CA1336216C - Pigment grinding vehicles containing quaternary ammonium and ternary sulfonium groups - Google Patents
Pigment grinding vehicles containing quaternary ammonium and ternary sulfonium groupsInfo
- Publication number
- CA1336216C CA1336216C CA000595208A CA595208A CA1336216C CA 1336216 C CA1336216 C CA 1336216C CA 000595208 A CA000595208 A CA 000595208A CA 595208 A CA595208 A CA 595208A CA 1336216 C CA1336216 C CA 1336216C
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- Prior art keywords
- pigment
- cationic
- paint
- paste
- grinding vehicle
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D17/00—Pigment pastes, e.g. for mixing in paints
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/14—Polycondensates modified by chemical after-treatment
- C08G59/1433—Polycondensates modified by chemical after-treatment with organic low-molecular-weight compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
- C08G59/62—Alcohols or phenols
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/44—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/44—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications
- C09D5/4488—Cathodic paints
- C09D5/4492—Cathodic paints containing special additives, e.g. grinding agents
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S524/00—Synthetic resins or natural rubbers -- part of the class 520 series
- Y10S524/901—Electrodepositable compositions
Abstract
A pigment paste suitable for use in cationic electrodeposition is disclosed. The pigment paste comprises a cationic resinous grinding vehicle derived from an epoxy resin containing both quaternary ammonium and ternary sulfonium salt groups. Also disclosed are cationic electrodeposition paints containing the pigment paste and the use of these paints in the process of cationic electrodeposition. The paste improves the stability of lead-containing cationic electrodeposition paints.
Description
-~ 33621 6 PIGMENT GRINDING VEHICLES CONTAINING
7QUAT~RNARY AMMONIUM AND T~RNARY SULFONIUM GROUPS
Back~round of the Invention 13Field of the Invention: The present invention relates to novel pigment pastes, to cationic electrodeposition paints cont~n~ng 15 the novel pigment pastes and to the use of these paints in the process of cationic electrodeposition.
17 Brief Description of the Prior Art: In the formulation of paints and especially electrodeposition paints, an important factor 19 is the introduction of pigments into the paint. The pigments are typically ground in a pigment grinding vehicle which acts as a 21 dispersing agent to form a paste and the resultant pigment paste is blended with a main resinous vehicle and optionally diluents to form 23 the paint. For electrodeposition paints, the pigment grinding vehicle preferably is a resinous material having the same charge as 25 the main resinous vehicle so that it will electrodeposit with the main resinous vehicle. Typical pigment grinding vehicles for 27 cationic electrodeposition are quaternary ammonium salt group-containing resins such as are described in U.S. Patents 4,007,154 and 29 4,186,124. Also, ternary sulfonium salt group-containing resins such as described in U.S. 4,715,898 can also be used as pigment grinding 31 vehicles.
One disadvantage associated with quaternary ammonium salt 33 group-contain~ng resins as pigment grinding vehicles is that they often result in relatively rough films. On the other hand, the 35 sulfonium salt group-containing resins such as described in the aforementioned U.S. offer an advantage over the quaternary ammonium 37 salt group-containing resins in that they result in smoother electrodeposited films, particularly films which deposit at higher 1 film builds. Unfortunately, it has been found that the sulfonium salt group-containing resins have a stability problem with 3 lead-contain~ng paints. Such paints for reasons which are not entirely understood are not particularly stable to the shearing 5 forces the paint encounters when it passes through a recirculating pump tyically used with industrial cationic electrodeposition baths.
7 In addition, it has been found that lead-containing paints which additionally contain the pigment carbon black result in a 9 particularly troublesome sedimentation which forms upon storage of the paint. Although the sedimentation problem can be overcome by 11 using quaternary ammonium group-contain~ng resins as the pigment grinding vehicles, rough films often result.
SummarY of the Invention The present invention provides for a lead-containing cationic electrodeposition paint comprising a film-forming cationic 17 electrodepositable resin, a pigment and a pigment grinding vehicle which is a cationic resin derived from an epoxy resin and containing 19 both quaternary ammonium and ternary sulfonium groups.
In another embodiment, the invention provides for a pigment 21 paste suitable for use in cationic electrodeposition comprising a cationic resinous grinding vehicle derived from an epoxy resin 23 contain~ng both quaternary ammonium and ternary sulfonium salt groups and a pigment component dispersed in the grinding vehicle. The 25 pigment component contains a lead-containing pigment and the pigment to resin solids weight ratio being at least 2:1.
27 The invention also provides for a method of coating an electrically conductive substrate serving as a cathode in an 29 electrical circuit comprising said cathode and an anode in an aqueous electrodeposition paint by passing electric current between the anode 31 and the cathode to cause the paint to deposit on the cathode. The aqueous electrodeposition paint being the lead-containing cationic 33 electrodeposition paint mentioned above.
~ 3 ~ 13362~6 1 Detailed Descri~tion The cationic resinous pigment grinding vehicle is derived 3 from an epoxy resin. The epoxy resins which are used are typically polymeric polyepoxides which have a 1,2-epoxy equivalency greater 5 than 1.0, that is, in which the average number of 1,2-epoxy groups per molecule is greater than one. Preferably, the epoxy resin will 7 have an epoxy equivalency of 1.8 to 2.2, most preferably about 2.
A useful class of polyepoxides are the polyglycidyl ethers 9 of polyphenols such as bisphenol F and bisphenol A, the latter being preferred. These may be prepared, for example, by etherification of 11 the polyphenol with epichlorohydrin or dichlorohydrin in the presence of alkali. The polyphenol may be 2,2-bis(4-hydroxy-phenyl)propane, 13 4,4'-dihydroxybenzophenone, 1,1-bis(4-hydroxy-phenyl)ethane, 4,4'-dihydroxydiphenylmethane or the like. Another quite useful 15 class of polyepoxides are produced similarly from novolak resins or similar polyphenol resins.
17 Also suitable are polyglycidyl ethers of aliphatic and cycloaliphatic polyols such as ethylene glycol, diethylene glycol, 19 1,2-propylene glycol, 1,4-butylene glycol, glycerol, 2,2-bis-(4-hydroxycyclohexyl)propane, and the like.
21 Other epoxides which may be employed are acrylic polymers containing epoxy groups. Preferably, these ac nlic polymers are 23 polymers produced by copolymerizing a polymerizable ethylenically unsaturated epoxy group-containing monomer with at least one other 25 ethylenically unsaturated monomer which is free of epoxy groups.
Examples of ethylenically unsaturated monomers containing 27 epoxy groups are those containing 1,2-epoxy groups and include glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether.
29 Examples of ethylenically unsaturated monomers which do not contain epoxy groups are alkyl esters of acrylic and methacrylic acid 31 containing from 1 to 20 atoms in the alkyl group. Specific examples of these acrylates and methacrylates are methyl methacrylate, ethyl 33 methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. Also, hydroxyalkyl esters of acrylic acid and 35 methacrylic acid containing from 2 to 4 atoms in the hydroxyalkyl group can be used. Examples include hydroxyethyl methacrylate and ` -1 hydroxypropyl acrylate. Suitable other copolymerizable ethylenically unsaturated monomers include vinyl aromatic compounds such as styrene 3 and vinyl toluene; nitriles such as acrylonitrile and methacryloni-trile; vinyl and vinylidene halides such as vinyl chloride and 5 vinylidene fluoride and vinyl esters such as vinyl acetate.
The epoxy group-containing ethylenically unsaturated 7 monomer is preferably used in amounts of from about 5 to 60, more preferably from 20 to 50 percent by weight of the total monomers used 9 in preparing the epoxy-cont~n~ng acrylic polymer. Of the remaining polymerizable ethylenically unsaturated monomers, preferably from 40 11 to 95 percent, more preferably from 50 to 80 percent by weight of the total monomers are the alkyl esters of acrylic and methacrylic acid.
13 The acrylic polymer may be prepared by solution polymerization techniques in the presence of suitable catalysts such 15 as organic peroxides or azo compounds, for example, benzoyl peroxide or N,N'-azobis(isobutyronitrile). The polymerization can be carried 17 out in an organic solution in which the monomers are soluble.
Suitable solvents are aromatic solvents such as xylene and toluene 19 and ketones such as methyl amyl ketone. Alternately, the acrylic polymer may be prepared by aqueous emulsion or dispersion 21 polymerization techniques.
The average molecular weight of the polyepoxide can vary 23 from about at least 200 to about 50,000. The polyglycidyl ethers have relatively low molecular weights, that is, from about 200 to 25 3000, whereas the epoxy-containing acrylic polymers have relatively high molecular weights, that is, from about 1000 to 50,000. Prefera-27 bly, the polyepoxide is a polyglycidyl ether of a polyphenol.
To incorporate the sulfonium and quaternary ammonium groups 29 into the cationic resin, the epoxy resin is typically reacted with asulfide-amine-acid mixture. The sulfide employed may be virtually 31 any sulfide which reacts with epoxy groups and which does not contain interfering groups. For example, the sulfide may be aliphatic, mixed 33 aliphatic-aromatic, aralkyl or cyclic. Examples of such sulfides include diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diphenyl 35 sulfide, dihexyl sulfide, ethylphenyl sulfide, tetramethylene sulfide, pentamethylene sulfide, thiodiethanol, thiodipropanol, 1 thiodibutanol and the like. Preferably, the sulfide is of the structure R-S-R' with R and R' being the same or different and being 3 alkyl or hydroxyalkyl cont~lnlng from 2 to 12 carbon atoms, preferably with at least one hydroxyl group being beta to sulfur.
5 The most preferred sulfide is thiodiethanol.
The amine is preferably a tertiary amine. The amine may be 7 unsubstituted or substituted with non-reactive substituents such as halogen or hydroxyl. Hydroxylamines such as alkanol and dialkanol 9 amines are preferred. Examples include dimethylethanolamine, dimethylpropanolamine and methyldiethanolamine.
11 The acid employed may be virtually any acid which forms the desired ternary sulfonium and quaternary ammonium salts upon reaction 13 with epoxy. Preferably, the acid is an organic carboxylic acid.
Examples of acids which may be employed are boric acid, formic acid, 15 lactic acid, acetic acid, propionic acid, butyric acid, dimethylolpro-pionic acid, hydrochloric acid, phosphoric acid and sulfuric acid, 17 with the dimethylolpropionic acid being preferred.
The ratio of sulfide and amine to acid is not unduly 19 critical. Since one mole of acid is utilized to form one mole of onium group (i.e., ternary sulfonium and quaternary ammonium salt 21 group), it is preferred that at least one mole of acid be present for each mole of sulfide and each mole of amine.
23 Preferably, the pigment grinding vehicle should contain from 0.25 to 1.4 milliequivalents of onium salt group per gram of 25 resin solids. Lower than the recommended amounts result in poor pigment wetting properties, whereas higher than the recommended 27 amount results in vehicles which are too water soluble.
Preferably, the pigment grinding vehicle contains from 0.05 29 to 1.20 milliequivalents of quaternary ammonium salt groups and from 0.20 to 1.35 milliequivalents of ternary sulfonium salt groups per 31 gram of resin solids to give the best blend of smoothness and stability in the resultant coating.
33 The sulfide-acid mixture and the epoxy resin are reacted by mixing the components usually at moderately elevated temperatures 35 such as 60 to 95C., preferably 70 to 85C. Solvent is not necessary although one is often used in order to afford better 1 33 62 1 ~
1 control of the reaction. Preferably, the solvent is an alcohol and/or water. Examples of alcohols are monoalkyl ethers of ethylene 3 glycol and of propylene glycol and aliphatic alcohols such as 2-butoxyethanol, 1-butoxy-2-propanol and butanol. Optionally, 5 additional non-protic solvents such as methyl isobutyl ketone or toluene can be used.
7 Preferably, alkyl phenoxy groups are present in the grinding vehicle. The alkyl phenol provides for higher film builds.
9 The alkyl phenoxy groups are typically of the structure:
11 R ~ R' 13 where R is an alkyl radical including branched and linear alkyl groups containing at least 4 and preferably from about 8 to 12 carbon 15 atoms. Examples of alkyl groups include tertiary butyl, allyl, octyl, nonyl and dodecyl. R' can be hydrogen or an alkyl group of 17 the type described for R. Examples of suitable alkyl phenoxy groups are those derived from alkyl phenols such as tertiary butyl phenol, 19 allyl phenol, octyl phenol, nonyl phenol, dinonyl phenol and dodecyl phenol, with nonyl phenol being preferred.
21 The alkyl phenoxy groups are incorporated into the grinding vehicle by reacting the epoxy resin with the corresponding alkyl 23 phenol. Reaction occurs readily, particularly in the presence of a catalyst such as ethyltriphenyl phosphonium iodide, benzyldimethyla-25 mine, 2-phenylimidazole or 2-ethyl-4-methylimidazole at a temperature of about 120 to 200C., preferably 140 to 180C. The epoxy resin 27 and alkyl phenol can be reacted neat or preferably in the presence of a solvent such as xylene, methyl isobutyl ketone or l-butoxy-2-29 propanol.
The order of reaction is not particularly critical although 31 preferably the epoxy resin is reacted first with the alkyl phenol andthen with the sulfide-amine-acid mixture. Since both the alkyl 33 phenol and sulfide-amine-acid mixture react with the epoxide functionality, the amounts and equivalents of the reactants should be 35 controlled so as to get the desired product.
~ 7 ~ 1 33621 6 1 The amount of alkyl phenoxy groups in the cationic resin is preferably from 1.9 to 25, more preferably from 5 to 20 percent by 3 weight based on total weight of cationic resin solids, that is, the weight of alkyl phenol divided by the total weight of reactants on a 5 solid basis used in making the cationic resin.
Pigment pastes of the present invention are prepared by 7 grinding or dispersing a pigment component which includes a lead-conta~n~ng pigment into the grinding vehicle described above.
9 For reasons not understood, lead in the cationic electrodeposition paints presents shear instability problems in the paint which the 11 pigment grinding vehicles of the present invention help to stabilize.
Examples of lead-containing pigments are basic lead 13 carbonate, basic lead silicate, lead oxide and lead cyanimide.
Examples of other pigments which may be used include titanium 15 dioxide, antimony oxide, zinc oxide, barium carbonate, calcium carbonate, aluminum silicate, silica, magnesium carbonate and 17 magnesium silicate. Color pigments may also be employed, for example, cadmium yellow, cadmium red, carbon black, phthalocyanine 19 blue, chrome yellow, toluidine red and hydrated iron oxide. Carbon black in combination with the lead presents a sedimentation problem 21 which the pigment grinding vehicles of the present invention help to stabilize.
23 Besides pigment and grinding vehicle, the paste in addition may contain optional ingredients such as wetting agents, surfactants 25 and defoamers.
Grinding is usually accomplished by the use of ball mills, 27 sand mills, Cowles dissolvers, continuous attritors and the like until the pigment has been reduced to a desired size and preferably 29 has been wetted by and dispersed by the grinding vehicle. After grinding, the particle size of the pigment should be in the range of 31 10 microns or less, preferably as small as practical. Generally, a Hegman grind gauge reading of about 6 to 8, preferably 7 to 8, is 33 employed.
Usually, grinding is conducted in an aqueous dispersion of 35 the vehicle. The amount of water present in the aqueous grind should be sufficient to produce a continuous aqueous phase. The aqueous -l ~3621 6 1 grind usually contains from about 30 to 70 percent solids. The use of more water merely reduces the effective capacity of the mill and 3 while less water can be employed, higher resultant viscosity may create problems in certain instances. Although the pigment paste is 5 usually prepared in the presence of water, water is not absolutely necessary and, in fact, the pigment dispersants of the present 7 invention can be used to prepare non-aqueous pigment pastes which are subsequently dispersible in water-based compositions. The 9 pigment-binder ratio in the grinding step is usually maintained within the range of about 1 to 10:1, preferably about 4 to 6:1.
11 Typically, the lead-cont~in~ng pigment is present in the paste in amounts of O.Ol to 5.0 percent by weight based on total 13 paste solids.
The carbon black when present is present in the paste in 15 amounts of O.OI to 5.0 percent based on total paste solids.
For a general review of pigment grinding in paint 17 formulation, reference may be made to: D. H. Parker, Principles of Surface Coatin~ Technolo~v, Interscience Publishers, New York (1965);
19 R. L. Yeates, Electropaintin~, Robert Draper Ltd., Teddington, ~ngl~n~ (1966); H. F. Payne, Or~anic Coatin~ Technolo~v, Vol. 2, 21 Wiley and Sons, New York (1961).
For use in electrodeposition, the pigment paste is combined 23 with a film-forming cationic electrodepositable resin which is the principal resin in the cationic electrodeposition process. Typical-25 ly, the film-forming cationic electrodepositable resin will constitute from 5 to 19.5 percent by weight resin solids of the 27 electrodeposition paint and the pigment grinding vehicle will constitute from O.l to 3 percent by weight resin solids of the 29 electrodeposition paint.
Examples of cationic electrodepositable resins include 31 amine salt group-containing resins such as the acid-solubilized reaction products of polyepoxides and primary or secondary amines 33 such as those described in U.S. Patents Nos. 3,663,389-; 3,984,299;
3,947,338 and 3,947,339. Usually, these amine salt group-containing 35 resins are used in combination with a blocked isocyanate curing agent. The isocyanate can be fully blocked as described in the 1 aforementioned U.S. Patent No. 3,984,299 or the isocyanate can be partially blocked and reacted with the resin backbone such as 3 described in U.S. Patent No. 3,947,338. Also, one-component compositions as described in U.S. Patent No. 4,134,866 and DE-OS
5 2,707,405 can be used as the film-forming resin. Besides the epoxy-amine reaction products, film-forming resins can also be 7 selected from cationic acrylic resins such as those described in U.S.
Patents Nos. 3,455,806 and 3,928,157.
9 Besides amine salt group-containing resins, quaternary ammonium salt group-containing resins can also be employed. Examples 11 of these resins are those which are formed from reacting an organic polyepoxide with a tertiary amine salt. Such resins are described in 13 U.S. Patents Nos. 3,962,165; 3,975,346 and 4,001,101. Examples of other cationic resins are ternary sulfonium salt group-containing 15 resins and quaternary phosphonium salt group-containing resins such as those described in U.S. Patents Nos. 3,793,278 and 3,984,922, 17 respectively. Also, film-forming resins which cure via transesterifi-cation such as described in published ~uropean Application No. 12463 can be 19 used. Further, cationic compositions prepared from Mannich bases such as described in U.S. Patent No. 4,134,932 can also be used.
21 Preferably, the cationic electrodepositable resin contains primary and/or secondary amine groups. Such resins are described in 23 U.S. Patents Nos. 3,663,389; 3,947,339 and 4,116,900. In U.S. Patent No. 3,947,339, a polyketimine derivative of a polyamine such as 25 diethylenetriamine or triethylenetetraamine is reacted with a polyepoxide. When the reaction product is neutralized with acid and 27 dispersed in water, free primary amine groups are generated. Also, equivalent products are formed when polyepoxide is reacted with 29 excess polyamines such as diethylenetriamine and triethylenetetraa-mine and the excess polyamine vacuum stripped from the reaction 31 mixture. Such products are described in U.S. Patents Nos. 3,663,389 and 4,116,900.
33 Enough of the pigment paste is used so that the final electrodepositable composition (electrodepositable resin plus pigment 35 paste and optional ingredient) has the proper color, opacity, application and film properties required for electrodeposition. In ~ 336216 1 most instances, the final electrodepositable composition has a pigment-to-binder (electrodepositable resin plus pigment dispersing 3 vehicle) ratio of between about 0.01 to about 0.5.
For electrodeposition, a bath conta~n~ng about 1 to 50, 5 usually from 5 to 30 percent by weight solids, that is, pigment plus resinous vehicle, is usually employed. The final electrodepositable 7 composition may contain in addition to the pigment dispersion and electrodeposition resin, ad~uvant resins, solvents, anti-oxidants, 9 surfactants and other adjuvants typically employed in an electrodeposition process.
11 Besides incorporating lead into the cationic electrodeposition paint through the pigment paste as described above, 13 the lead can also be incorporated into the paint by simply adding a soluble lead salt such as lead acetate, lead lactate or lead oxide to 15 the paint. Addition can be to the paint itself, to the pigment paste or to the cationic electrodepositable resin prior to combination with 17 the paste to form the paint. Lead contents (both soluble and insoluble) of from 200 to 5000 parts per million based on total 19 weight of cationic electrodeposition paint are typical.
For electrodeposition, the aqueous composition is placed in 21 contact with an electrically conductive anode and an electrically conductive cathode in an electric circuit. While in contact with the 23 bath conta~n~ng the coating composition, an adherent film of the coating composition is deposited on the cathode. The conditions 25 under which the electrodeposition is carried out are, in general, similar to those used in the electrodeposition of other types of 27 coatings. The applied voltage may be varied greatly and can be, for example, as low as one volt or as high as several thousand volts, 29 although typically between 50 volts and 500 volts are usually employed. The current density is usually between about 0.25 ampere 31 and 15 amperes per square foot and tends to decrease during electrodeposition. The method of the invention is applicable to the 33 coating of any conductive substrate and especially metal such as steel, al~ ~ , copper and the like. After deposition, the coating 35 is cured at elevated temperatures by any convenient method such as in 1 baking ovens or with banks of infra-red heat lamps. Curing temperatures of 200-400F. (93-204C.) and curing times of 10 to 60 3 minutes are typical.
Illustrating the invention are the following examples which 5 are not to be construed as limiting the invention to their details.
All parts and percentages in the examples as well as throughout the 7 specification are by weight unless otherwise specified.
The following examples (I-IV) show the formulation of 11 various cationic electrodeposition paints containing lead pigment and carbon black. Two paints (Examples I and III) were prepared using 13 the pigment grinding vehicle of the present invention (Example F) which contained both ternary sulfonium and quaternary ammonium salt 15 groups, and two paints (Examples II and IV) were prepared using the pigment grinding vehicle of the prior art (Example E) which contained 17 only ternary sulfonium groups. The paints were evaluated for pump stability and for stability against sedimenting.
19 In preparing the cationic electrodeposition paints, the following cationic resin, additive, pigment grinding vehicles, 21 pigment pastes and catalyst pastes were used.
23 ExamPle A
A cationic film-forming resin was prepared by reacting a 25 polyepoxide with N-methylethanolamine and the methyl isobutyl diketimine of diethylenetriamine. The reaction product was combined 27 with a fully blocked polyisocyanate and solubilized with acid as generally described in Example 2 of published European Application 236,050.
ADDITIVE
31 Example B
A polyoxyalkylenepolyamine-polyepoxide adduct having an 33 amine to epoxide equivalent ratio of 1.34/1 was prepared, solubilized with lactic acid and dispersed in water (solids content 38.7 percent) 35 as generally described in Example J of U.S. 4,615,779.
- 12 - l 3 3 6 2 1 6 PIGMENT GRINDING VEHICLE
Example C
A pigment grinding vehicle was prepared as generally described in Example M of U.S. Patent No. 4,615,779.
Example E
A pigment grinding vehicle was prepared by reacting a polyglycidyl ether of bisphenol A with nonyl phenol (1.9 percent by weight) and thiodiethanol and dimethylolpropionic acid (0.992 milliequivalents of sulfonium per gram of resin) as follows:
Parts by Weight Solids Ingredients (in grams) (in grams) Equivalents EPON* 8281 533.2 533.2 2.836 Bisphenol A 199.6 199.6 1.751 Nonyl phenol 19.2 19.2 0.086 Ethyltriphenyl phosphonium iodide 0.75 Monobutyl ether of propylene glycol 201.6 Thiodiethanol 122.1 122.1 1.0 Dimethylolpropionic acid 134.1 134.1 1.0 Deionized water 30.6 I Polyglycidyl ether of bisphenol A, available from Shell Chemical Co.
The EPON* 828, bisphenol A and nonyl phenol were charged to a reaction vessel and heated to 107C. and held at this temperature until the bisphenol A dissolves. The ethyltriphenyl phosphonium iodide was then added and the reaction mixture heated to 125C. to initiate an exotherm. The reaction mixture was m~int~ined at exotherm for about one hour until a viscosity of P (measured as a 50 percent resin solids solution in 2-methoxypropanol, DOWANOL* PM) was obtained (epoxy equivalent weight of about 763). The reaction mixture was cooled to 75C. followed by the addition of the monobutyl ether of propylene glycol, thiodiethanol, dimethylolpropionic acid and water.
The reaction mixture was heated to 70-75C. and held at *Trade-mark y \
- 13 - I 3 3 6 2 1 ~
1 this temperature until an acid value of 3.36 was obtained. The reaction mixture was then cooled and thinned with additional water to 3 a solids content of 36.2 percent.
ExamPle F
A pigment grinding vehicle similar to Example E was 7 prepared but in which the polyglycidyl ether of bisphenol A was reacted with a mixture of thiodiethanol and dimethylethanolamine to 9 form a vehicle containing both ternary sulfonium and quaternary ammonium groups.
11 Parts by Weight Solids In~redients (in ~rams) (in ~rams) Equivalents 13 EPON 828 533.2 533.2 2.836 Bisphenol A 199.6 199.6 1.751 15 Nonyl phenol 19.2 19.2 0.086 Ethyltriphenyl 17 phosphonium iodide 0.5 - -Monobutyl ether of 19 propylene glycol 200.5 Sulfide-amine mixturel177.3 146.7 0.785 (sulfide) 21 0.215 (amine) 0.237 (acid) 23 Dimethylolpropionic acid 102.3 102.3 0.763 lThe sulfide-amine mixture was prepared from the following 25 ingredients:
Parts by Weight Solids 27 In~redients (in ~rams) (in ~rams) Equi'valents Thiodiethanol 287.4 287.4 2.355 29 Dimethylethanolamine57.6 57.6 0.645 Dimethylolpropionic acid 95.1 95.1 0.710 31 Deionized water 91.8 The thiodiethanol and dimethylethanolamine were charged to a reaction 33 vessel and mixed. Dimethylolpropionic acid and water were then added and the mixture stirred at 60C. until a solution was obtained.
` -t336216 1 The EPON 828, bisphenol A and nonyl phenol were charged to a reaction vessel and heated to 107C. and held at this temperature 3 until the bisphenol A dissolves. The ethyltriphenyl phosphonium iodide was then added and the reaction mixture heated to 125C. to 5 initiate an exotherm. The reaction mixture was maintained at exotherm for about one hour until a viscosity of P (50 percent in 7 DOWANOL PM, epoxy equivalent of 775) was achieved. After addition of the monobutyl ether of propylene glycol, sulfide-amine mixture and 9 dimethylolpropionic acid, the reactants were heated to 70-75C.
until an acid value of 5.61 was obtained. The reaction mixture was 11 cooled and thinned with deionized water to a solids content of 32.1 percent.
CATALYST PASTE
ExamPle G
Dibutyltin oxide catalyst was dispersed in the grinding 17 vehicle prepared as described above in Example C in the following charge ratio:
19 In~redients Parts bv Wei~ht Quaternary ammonium salt group-21 cont~nlng pigment grinding vehicle prepared as described in Example C 145 23 Deioni~ed water 321.6 Dibutyltin oxide 200 The above ingredients were mixed together and ground in a mill to a Hegman No. 7 grind.
ExamPle H
29 Dibutyltin oxide catalyst was dispersed in the grinding vehicle prepared as described above in Example E in the following 31 charge ratio:
1 In~redients Parts by Wei~ht (in ~rams) Ternary sulfonium salt group-3 containing pigment grinding vehicle prepared as described above in Example E 735.2 SURFYNOL* 104El 2.25 7 Deionized water 340.7 Dibutyltin oxide 562.5 9 lAcetylenic alcohol available from Air Products and Chemicals Inc.
11 The above ingredients were mixed together and ground in a sand mill for 3 hours to a Hegman No. 7 grind.
ExamPle J
Dibutyltin oxide catalyst was dispersed in the grinding vehicle prepared as descrlbed above in Example F in the following 17 charge ratio:
In~redients Parts by Wei~ht (in ~rams) 19 Mixed quaternary ammonium-ternary sulfonium salt group-containing 21 pigment grinding vehicle prepared as described above in Example F 732.9 23 Deionized water 363.2 Dibutyltin oxide 500.0 The above ingredients were mixed together and ground in a sand mill for 3 hours to a Hegman No. 7 grind.
PIGMENT PASTE
29 Example K
A pigment paste was prepared by dispersing clay, titanium 31 dioxide and lead silicate in the pigment grinding vehicle of Example E as follows:
33 Ingredients Parts bY Wei~ht ~in ~rams) Pigment grinding vehicle of Example E 498.0 Catalyst paste of Example H 116.4 Deionized water 206.4 37 Clay 16.8 Titanium dioxide 701.0 39 Lead silicate 61.4 * Trade-mark ~1. .f ~
1 The above ingredients were ground together in a sand mill for 45 minutes to a Hegman No. 7 grind.
ExamDle L
A pigment paste was prepared by dispersing clay, titanium dioxide and lead silicate in the pigment grinding vehicle of Example 7 F as follows:
In~redients Parts bY Wei~ht (in ~rams) 9 Pigment grinding vehicle of Example F 482.3 Deionized water 222.1 11 Catalyst pacte 116.4 Clay 16.8 13 Titanium dioxide 701.0 Lead silicate 61.4 The ingredients were ground together in a sand mill for 45 minutes to a Hegman No. 7 grind.
Exam~le M
19 A pigment paste was prepared by dispersing lead silicate, carbon black and titanium dioxide in a mixed pigment grinding vehicle 21 consisting of the pigment grinding vehicle of Example F and of Example C.
23 In~redients Parts bY Wei~ht (in ~rams) Pigment grinding vehicle of Example F 275.3 Deionized water 286.5 , Pigment grinding vehicle of Example C 177.9 27 Lead silicate 64.3 Carbon black 28.4 29 Titanium dioxide 848.3 Catalyst paste of Example G 179.3 31 The ingredients were ground together in a sand mill to a Hegman No. 7 grind.
1 3362 1 ~
1 ExamPle N
A pigment paste was prepared by dispersing lead silicate, 3 carbon black and titanium dioxide in a mixed pigment grinding vehicle consisting of the pigment grinding vehicle of Example E and of 5 Example C.
In~redients Parts bY Wei~ht (in ~rams) 7 Pigment grinding vehicle of Example E 270.1 Deionized water 291.7 9 Pigment grinding vehicle of Example C 177.9 Lead silicate 64.3 11 Carbon black 28.4 Titanium dioxide 848.3 13 Catalyst paste of Example G 179.3 The above ingredients were ground in a sand mill to a 15 Hegman No. 7 grind.
The pigment grinding vehicle prepared as described 17 immediately above (500.1 grams) was mixed with an additional 8 grams of deionized water to form the final pigment paste.
PAINTS
21 ExamPle I
A cationic electrodeposition paint was prepared by mixing 23 together the following ingredients in the order indicated in a one gallon paint can under agitation from an overhead stirrer:
In~redients Parts by WeiRht (in ~rams) Cationic resin of Example A1457.6 27 Additive of Example B 160.5 Plasticizerl 37.9 29 Deionized water 1751.9 Pigment paste of Example K392.1 31 lPropoxylated cresol available from Rohm and Haas Co. as WP 1.
The paint formulated as described above was tested for pump 33 stability and resistance to sedimentation. The results are reported in the table below.
- 18 - 13~6216 1 Example II
A cationic electrodeposition paint was prepared as 3 generally described in Example I from the following ingredients:
In~redientsParts bY Wei~ht (in ~rams) Cationic resin of Example A 1457.3 Additive of Example B160.5 7 Plasticizer of Example I37.9 Deionized water 1749.4 9 Pigment paste of Example L 394.4 11 ExamPle III
A cationic electrodeposition paint was prepared as 13 generally described above in Example I from the following ingredients:
In~redients Parts bY Wei~ht (in ~rams~
Cationic resin of Example A 1328.8 Additive of Example B 146.3 17 Plasticizer of Example I 34.5 Deionized water 1942.3 19 Pigment paste of Example M 348.1 The cationic electrodeposition paint was passed through an 21 ultrafilter to the extent of 20 percent of its volume. The ultrafiltrate was replaced with deionized water. Phosphated 23 (BONDERITE* 40) steel panels were cathodically electrodeposited in the paint at a voltage of 275 volts for 2 minutes at a bath temperature 25 of 83F. (28C.) to form a continuous film. The paint was tested for pump stability and for resistance to sedimentation. The results are 27 reported in the table below.
29 Example IV
A cationic electrodeposition paint was prepared as 31 generally described above in Example I as follows:
In~redientsParts by Wei~ht (in ~rams~
33 Cationic resin of Example A 1328.9 Additive of Example B146.3 Plasticizer of Example I34.5 Deionized water 1983.7 37 Pigment paste of Example N 342.6 *Trade-mark 1 3 3 6 2 1 b 1 The paint was passed through an ultrafilter to 20 percent of its initial volume and the ultrafiltrate replaced with deionized 3 water. Phosphated steel panels were cathodically electrodeposited in the bath at 275 volts for 2 minutes at a bath temperature of 83F.
5 (28C.) to form a continuous film. The paint was tested for pump stability and for resistance to sedimentation. The results are 7 reported in the table below.
TABLE
9Pump Stability and Resistance to Sedimentation 11of Paints of ExamPles I-IV
Pigment Pigment 13 Paint Grinding Grinding Pump Example Vehicle Vehicle Stabilityl Sedimentation 15 No. (Exam~le~ (Ty~e~ (~rams~ Ratin~2 _ 17 I E ternary sulfonium 5.2 0/0 19 II F mixed ternary 2.2 5/8 sulfonium-quaternary 21 ammonium 23 III F+C mixed sulfonium- 0.3 9-3/4 / 10 quaternary ammonium + quaternary ammonium 27 IV E+C ternary sulfonium + 5.9 2/0 quaternary ammonium lThe pump stability is a measure of the resistance of the 31 paint to shearing forces. The pump stability was determined by recirculating one gallon of paint in a centrifugal pump (Little Giant 33 4MD) for 8 hours at a paint temperature of 90F. (32C.). The pigment pastes used in formulating the paints were heat aged for 3 35 days at 140F. (60C.) prior to formulation. The paint is then passed through a 200-mesh screen and the grams of sludge collected on 37 the screen is weighed and reported. The lower the amount of sludge collected, the greater the pump stability.
39 2The sedimentation rating is a measure of the sedimenting tendency of the paint and the ease of reincorporating the sediment 41 back into the paint. The pigment pastes used in formulating the paints were heat aged for 3 days at 140F. (60C.) prior to -- 20 - ~ 336216 1 formulation. In determining the sedimentation rating, a sample of the paint is placed in a 4-ounce glass ~ar and allowed to stand at 3 room temperature for 7 hours. The jar is then placed in an oven at 140F. (60C.) for 8 hours. The ~ar is then removed from the oven, 5 allowed to cool at room temperature and placed upside down in a Burell Model 75 wrist action shaker. Shaking is continued for 30 7 minutes. The reincorporation of sediment back into the paint is evaluated and given a first rating. The jar is removed from the 9 shaker and the bottom of the jar scraped thoroughly with a spatula.
The ~ar is shaken an additional 30 minutes, removed from the shaker 11 and allowed to stand in an upright position for an additional 10 minutes. The reincorporation of the sediment back into the paint is 13 given a second rating. A value of 10 is rated as excellent and 0 is rated very poor.
7QUAT~RNARY AMMONIUM AND T~RNARY SULFONIUM GROUPS
Back~round of the Invention 13Field of the Invention: The present invention relates to novel pigment pastes, to cationic electrodeposition paints cont~n~ng 15 the novel pigment pastes and to the use of these paints in the process of cationic electrodeposition.
17 Brief Description of the Prior Art: In the formulation of paints and especially electrodeposition paints, an important factor 19 is the introduction of pigments into the paint. The pigments are typically ground in a pigment grinding vehicle which acts as a 21 dispersing agent to form a paste and the resultant pigment paste is blended with a main resinous vehicle and optionally diluents to form 23 the paint. For electrodeposition paints, the pigment grinding vehicle preferably is a resinous material having the same charge as 25 the main resinous vehicle so that it will electrodeposit with the main resinous vehicle. Typical pigment grinding vehicles for 27 cationic electrodeposition are quaternary ammonium salt group-containing resins such as are described in U.S. Patents 4,007,154 and 29 4,186,124. Also, ternary sulfonium salt group-containing resins such as described in U.S. 4,715,898 can also be used as pigment grinding 31 vehicles.
One disadvantage associated with quaternary ammonium salt 33 group-contain~ng resins as pigment grinding vehicles is that they often result in relatively rough films. On the other hand, the 35 sulfonium salt group-containing resins such as described in the aforementioned U.S. offer an advantage over the quaternary ammonium 37 salt group-containing resins in that they result in smoother electrodeposited films, particularly films which deposit at higher 1 film builds. Unfortunately, it has been found that the sulfonium salt group-containing resins have a stability problem with 3 lead-contain~ng paints. Such paints for reasons which are not entirely understood are not particularly stable to the shearing 5 forces the paint encounters when it passes through a recirculating pump tyically used with industrial cationic electrodeposition baths.
7 In addition, it has been found that lead-containing paints which additionally contain the pigment carbon black result in a 9 particularly troublesome sedimentation which forms upon storage of the paint. Although the sedimentation problem can be overcome by 11 using quaternary ammonium group-contain~ng resins as the pigment grinding vehicles, rough films often result.
SummarY of the Invention The present invention provides for a lead-containing cationic electrodeposition paint comprising a film-forming cationic 17 electrodepositable resin, a pigment and a pigment grinding vehicle which is a cationic resin derived from an epoxy resin and containing 19 both quaternary ammonium and ternary sulfonium groups.
In another embodiment, the invention provides for a pigment 21 paste suitable for use in cationic electrodeposition comprising a cationic resinous grinding vehicle derived from an epoxy resin 23 contain~ng both quaternary ammonium and ternary sulfonium salt groups and a pigment component dispersed in the grinding vehicle. The 25 pigment component contains a lead-containing pigment and the pigment to resin solids weight ratio being at least 2:1.
27 The invention also provides for a method of coating an electrically conductive substrate serving as a cathode in an 29 electrical circuit comprising said cathode and an anode in an aqueous electrodeposition paint by passing electric current between the anode 31 and the cathode to cause the paint to deposit on the cathode. The aqueous electrodeposition paint being the lead-containing cationic 33 electrodeposition paint mentioned above.
~ 3 ~ 13362~6 1 Detailed Descri~tion The cationic resinous pigment grinding vehicle is derived 3 from an epoxy resin. The epoxy resins which are used are typically polymeric polyepoxides which have a 1,2-epoxy equivalency greater 5 than 1.0, that is, in which the average number of 1,2-epoxy groups per molecule is greater than one. Preferably, the epoxy resin will 7 have an epoxy equivalency of 1.8 to 2.2, most preferably about 2.
A useful class of polyepoxides are the polyglycidyl ethers 9 of polyphenols such as bisphenol F and bisphenol A, the latter being preferred. These may be prepared, for example, by etherification of 11 the polyphenol with epichlorohydrin or dichlorohydrin in the presence of alkali. The polyphenol may be 2,2-bis(4-hydroxy-phenyl)propane, 13 4,4'-dihydroxybenzophenone, 1,1-bis(4-hydroxy-phenyl)ethane, 4,4'-dihydroxydiphenylmethane or the like. Another quite useful 15 class of polyepoxides are produced similarly from novolak resins or similar polyphenol resins.
17 Also suitable are polyglycidyl ethers of aliphatic and cycloaliphatic polyols such as ethylene glycol, diethylene glycol, 19 1,2-propylene glycol, 1,4-butylene glycol, glycerol, 2,2-bis-(4-hydroxycyclohexyl)propane, and the like.
21 Other epoxides which may be employed are acrylic polymers containing epoxy groups. Preferably, these ac nlic polymers are 23 polymers produced by copolymerizing a polymerizable ethylenically unsaturated epoxy group-containing monomer with at least one other 25 ethylenically unsaturated monomer which is free of epoxy groups.
Examples of ethylenically unsaturated monomers containing 27 epoxy groups are those containing 1,2-epoxy groups and include glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether.
29 Examples of ethylenically unsaturated monomers which do not contain epoxy groups are alkyl esters of acrylic and methacrylic acid 31 containing from 1 to 20 atoms in the alkyl group. Specific examples of these acrylates and methacrylates are methyl methacrylate, ethyl 33 methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. Also, hydroxyalkyl esters of acrylic acid and 35 methacrylic acid containing from 2 to 4 atoms in the hydroxyalkyl group can be used. Examples include hydroxyethyl methacrylate and ` -1 hydroxypropyl acrylate. Suitable other copolymerizable ethylenically unsaturated monomers include vinyl aromatic compounds such as styrene 3 and vinyl toluene; nitriles such as acrylonitrile and methacryloni-trile; vinyl and vinylidene halides such as vinyl chloride and 5 vinylidene fluoride and vinyl esters such as vinyl acetate.
The epoxy group-containing ethylenically unsaturated 7 monomer is preferably used in amounts of from about 5 to 60, more preferably from 20 to 50 percent by weight of the total monomers used 9 in preparing the epoxy-cont~n~ng acrylic polymer. Of the remaining polymerizable ethylenically unsaturated monomers, preferably from 40 11 to 95 percent, more preferably from 50 to 80 percent by weight of the total monomers are the alkyl esters of acrylic and methacrylic acid.
13 The acrylic polymer may be prepared by solution polymerization techniques in the presence of suitable catalysts such 15 as organic peroxides or azo compounds, for example, benzoyl peroxide or N,N'-azobis(isobutyronitrile). The polymerization can be carried 17 out in an organic solution in which the monomers are soluble.
Suitable solvents are aromatic solvents such as xylene and toluene 19 and ketones such as methyl amyl ketone. Alternately, the acrylic polymer may be prepared by aqueous emulsion or dispersion 21 polymerization techniques.
The average molecular weight of the polyepoxide can vary 23 from about at least 200 to about 50,000. The polyglycidyl ethers have relatively low molecular weights, that is, from about 200 to 25 3000, whereas the epoxy-containing acrylic polymers have relatively high molecular weights, that is, from about 1000 to 50,000. Prefera-27 bly, the polyepoxide is a polyglycidyl ether of a polyphenol.
To incorporate the sulfonium and quaternary ammonium groups 29 into the cationic resin, the epoxy resin is typically reacted with asulfide-amine-acid mixture. The sulfide employed may be virtually 31 any sulfide which reacts with epoxy groups and which does not contain interfering groups. For example, the sulfide may be aliphatic, mixed 33 aliphatic-aromatic, aralkyl or cyclic. Examples of such sulfides include diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diphenyl 35 sulfide, dihexyl sulfide, ethylphenyl sulfide, tetramethylene sulfide, pentamethylene sulfide, thiodiethanol, thiodipropanol, 1 thiodibutanol and the like. Preferably, the sulfide is of the structure R-S-R' with R and R' being the same or different and being 3 alkyl or hydroxyalkyl cont~lnlng from 2 to 12 carbon atoms, preferably with at least one hydroxyl group being beta to sulfur.
5 The most preferred sulfide is thiodiethanol.
The amine is preferably a tertiary amine. The amine may be 7 unsubstituted or substituted with non-reactive substituents such as halogen or hydroxyl. Hydroxylamines such as alkanol and dialkanol 9 amines are preferred. Examples include dimethylethanolamine, dimethylpropanolamine and methyldiethanolamine.
11 The acid employed may be virtually any acid which forms the desired ternary sulfonium and quaternary ammonium salts upon reaction 13 with epoxy. Preferably, the acid is an organic carboxylic acid.
Examples of acids which may be employed are boric acid, formic acid, 15 lactic acid, acetic acid, propionic acid, butyric acid, dimethylolpro-pionic acid, hydrochloric acid, phosphoric acid and sulfuric acid, 17 with the dimethylolpropionic acid being preferred.
The ratio of sulfide and amine to acid is not unduly 19 critical. Since one mole of acid is utilized to form one mole of onium group (i.e., ternary sulfonium and quaternary ammonium salt 21 group), it is preferred that at least one mole of acid be present for each mole of sulfide and each mole of amine.
23 Preferably, the pigment grinding vehicle should contain from 0.25 to 1.4 milliequivalents of onium salt group per gram of 25 resin solids. Lower than the recommended amounts result in poor pigment wetting properties, whereas higher than the recommended 27 amount results in vehicles which are too water soluble.
Preferably, the pigment grinding vehicle contains from 0.05 29 to 1.20 milliequivalents of quaternary ammonium salt groups and from 0.20 to 1.35 milliequivalents of ternary sulfonium salt groups per 31 gram of resin solids to give the best blend of smoothness and stability in the resultant coating.
33 The sulfide-acid mixture and the epoxy resin are reacted by mixing the components usually at moderately elevated temperatures 35 such as 60 to 95C., preferably 70 to 85C. Solvent is not necessary although one is often used in order to afford better 1 33 62 1 ~
1 control of the reaction. Preferably, the solvent is an alcohol and/or water. Examples of alcohols are monoalkyl ethers of ethylene 3 glycol and of propylene glycol and aliphatic alcohols such as 2-butoxyethanol, 1-butoxy-2-propanol and butanol. Optionally, 5 additional non-protic solvents such as methyl isobutyl ketone or toluene can be used.
7 Preferably, alkyl phenoxy groups are present in the grinding vehicle. The alkyl phenol provides for higher film builds.
9 The alkyl phenoxy groups are typically of the structure:
11 R ~ R' 13 where R is an alkyl radical including branched and linear alkyl groups containing at least 4 and preferably from about 8 to 12 carbon 15 atoms. Examples of alkyl groups include tertiary butyl, allyl, octyl, nonyl and dodecyl. R' can be hydrogen or an alkyl group of 17 the type described for R. Examples of suitable alkyl phenoxy groups are those derived from alkyl phenols such as tertiary butyl phenol, 19 allyl phenol, octyl phenol, nonyl phenol, dinonyl phenol and dodecyl phenol, with nonyl phenol being preferred.
21 The alkyl phenoxy groups are incorporated into the grinding vehicle by reacting the epoxy resin with the corresponding alkyl 23 phenol. Reaction occurs readily, particularly in the presence of a catalyst such as ethyltriphenyl phosphonium iodide, benzyldimethyla-25 mine, 2-phenylimidazole or 2-ethyl-4-methylimidazole at a temperature of about 120 to 200C., preferably 140 to 180C. The epoxy resin 27 and alkyl phenol can be reacted neat or preferably in the presence of a solvent such as xylene, methyl isobutyl ketone or l-butoxy-2-29 propanol.
The order of reaction is not particularly critical although 31 preferably the epoxy resin is reacted first with the alkyl phenol andthen with the sulfide-amine-acid mixture. Since both the alkyl 33 phenol and sulfide-amine-acid mixture react with the epoxide functionality, the amounts and equivalents of the reactants should be 35 controlled so as to get the desired product.
~ 7 ~ 1 33621 6 1 The amount of alkyl phenoxy groups in the cationic resin is preferably from 1.9 to 25, more preferably from 5 to 20 percent by 3 weight based on total weight of cationic resin solids, that is, the weight of alkyl phenol divided by the total weight of reactants on a 5 solid basis used in making the cationic resin.
Pigment pastes of the present invention are prepared by 7 grinding or dispersing a pigment component which includes a lead-conta~n~ng pigment into the grinding vehicle described above.
9 For reasons not understood, lead in the cationic electrodeposition paints presents shear instability problems in the paint which the 11 pigment grinding vehicles of the present invention help to stabilize.
Examples of lead-containing pigments are basic lead 13 carbonate, basic lead silicate, lead oxide and lead cyanimide.
Examples of other pigments which may be used include titanium 15 dioxide, antimony oxide, zinc oxide, barium carbonate, calcium carbonate, aluminum silicate, silica, magnesium carbonate and 17 magnesium silicate. Color pigments may also be employed, for example, cadmium yellow, cadmium red, carbon black, phthalocyanine 19 blue, chrome yellow, toluidine red and hydrated iron oxide. Carbon black in combination with the lead presents a sedimentation problem 21 which the pigment grinding vehicles of the present invention help to stabilize.
23 Besides pigment and grinding vehicle, the paste in addition may contain optional ingredients such as wetting agents, surfactants 25 and defoamers.
Grinding is usually accomplished by the use of ball mills, 27 sand mills, Cowles dissolvers, continuous attritors and the like until the pigment has been reduced to a desired size and preferably 29 has been wetted by and dispersed by the grinding vehicle. After grinding, the particle size of the pigment should be in the range of 31 10 microns or less, preferably as small as practical. Generally, a Hegman grind gauge reading of about 6 to 8, preferably 7 to 8, is 33 employed.
Usually, grinding is conducted in an aqueous dispersion of 35 the vehicle. The amount of water present in the aqueous grind should be sufficient to produce a continuous aqueous phase. The aqueous -l ~3621 6 1 grind usually contains from about 30 to 70 percent solids. The use of more water merely reduces the effective capacity of the mill and 3 while less water can be employed, higher resultant viscosity may create problems in certain instances. Although the pigment paste is 5 usually prepared in the presence of water, water is not absolutely necessary and, in fact, the pigment dispersants of the present 7 invention can be used to prepare non-aqueous pigment pastes which are subsequently dispersible in water-based compositions. The 9 pigment-binder ratio in the grinding step is usually maintained within the range of about 1 to 10:1, preferably about 4 to 6:1.
11 Typically, the lead-cont~in~ng pigment is present in the paste in amounts of O.Ol to 5.0 percent by weight based on total 13 paste solids.
The carbon black when present is present in the paste in 15 amounts of O.OI to 5.0 percent based on total paste solids.
For a general review of pigment grinding in paint 17 formulation, reference may be made to: D. H. Parker, Principles of Surface Coatin~ Technolo~v, Interscience Publishers, New York (1965);
19 R. L. Yeates, Electropaintin~, Robert Draper Ltd., Teddington, ~ngl~n~ (1966); H. F. Payne, Or~anic Coatin~ Technolo~v, Vol. 2, 21 Wiley and Sons, New York (1961).
For use in electrodeposition, the pigment paste is combined 23 with a film-forming cationic electrodepositable resin which is the principal resin in the cationic electrodeposition process. Typical-25 ly, the film-forming cationic electrodepositable resin will constitute from 5 to 19.5 percent by weight resin solids of the 27 electrodeposition paint and the pigment grinding vehicle will constitute from O.l to 3 percent by weight resin solids of the 29 electrodeposition paint.
Examples of cationic electrodepositable resins include 31 amine salt group-containing resins such as the acid-solubilized reaction products of polyepoxides and primary or secondary amines 33 such as those described in U.S. Patents Nos. 3,663,389-; 3,984,299;
3,947,338 and 3,947,339. Usually, these amine salt group-containing 35 resins are used in combination with a blocked isocyanate curing agent. The isocyanate can be fully blocked as described in the 1 aforementioned U.S. Patent No. 3,984,299 or the isocyanate can be partially blocked and reacted with the resin backbone such as 3 described in U.S. Patent No. 3,947,338. Also, one-component compositions as described in U.S. Patent No. 4,134,866 and DE-OS
5 2,707,405 can be used as the film-forming resin. Besides the epoxy-amine reaction products, film-forming resins can also be 7 selected from cationic acrylic resins such as those described in U.S.
Patents Nos. 3,455,806 and 3,928,157.
9 Besides amine salt group-containing resins, quaternary ammonium salt group-containing resins can also be employed. Examples 11 of these resins are those which are formed from reacting an organic polyepoxide with a tertiary amine salt. Such resins are described in 13 U.S. Patents Nos. 3,962,165; 3,975,346 and 4,001,101. Examples of other cationic resins are ternary sulfonium salt group-containing 15 resins and quaternary phosphonium salt group-containing resins such as those described in U.S. Patents Nos. 3,793,278 and 3,984,922, 17 respectively. Also, film-forming resins which cure via transesterifi-cation such as described in published ~uropean Application No. 12463 can be 19 used. Further, cationic compositions prepared from Mannich bases such as described in U.S. Patent No. 4,134,932 can also be used.
21 Preferably, the cationic electrodepositable resin contains primary and/or secondary amine groups. Such resins are described in 23 U.S. Patents Nos. 3,663,389; 3,947,339 and 4,116,900. In U.S. Patent No. 3,947,339, a polyketimine derivative of a polyamine such as 25 diethylenetriamine or triethylenetetraamine is reacted with a polyepoxide. When the reaction product is neutralized with acid and 27 dispersed in water, free primary amine groups are generated. Also, equivalent products are formed when polyepoxide is reacted with 29 excess polyamines such as diethylenetriamine and triethylenetetraa-mine and the excess polyamine vacuum stripped from the reaction 31 mixture. Such products are described in U.S. Patents Nos. 3,663,389 and 4,116,900.
33 Enough of the pigment paste is used so that the final electrodepositable composition (electrodepositable resin plus pigment 35 paste and optional ingredient) has the proper color, opacity, application and film properties required for electrodeposition. In ~ 336216 1 most instances, the final electrodepositable composition has a pigment-to-binder (electrodepositable resin plus pigment dispersing 3 vehicle) ratio of between about 0.01 to about 0.5.
For electrodeposition, a bath conta~n~ng about 1 to 50, 5 usually from 5 to 30 percent by weight solids, that is, pigment plus resinous vehicle, is usually employed. The final electrodepositable 7 composition may contain in addition to the pigment dispersion and electrodeposition resin, ad~uvant resins, solvents, anti-oxidants, 9 surfactants and other adjuvants typically employed in an electrodeposition process.
11 Besides incorporating lead into the cationic electrodeposition paint through the pigment paste as described above, 13 the lead can also be incorporated into the paint by simply adding a soluble lead salt such as lead acetate, lead lactate or lead oxide to 15 the paint. Addition can be to the paint itself, to the pigment paste or to the cationic electrodepositable resin prior to combination with 17 the paste to form the paint. Lead contents (both soluble and insoluble) of from 200 to 5000 parts per million based on total 19 weight of cationic electrodeposition paint are typical.
For electrodeposition, the aqueous composition is placed in 21 contact with an electrically conductive anode and an electrically conductive cathode in an electric circuit. While in contact with the 23 bath conta~n~ng the coating composition, an adherent film of the coating composition is deposited on the cathode. The conditions 25 under which the electrodeposition is carried out are, in general, similar to those used in the electrodeposition of other types of 27 coatings. The applied voltage may be varied greatly and can be, for example, as low as one volt or as high as several thousand volts, 29 although typically between 50 volts and 500 volts are usually employed. The current density is usually between about 0.25 ampere 31 and 15 amperes per square foot and tends to decrease during electrodeposition. The method of the invention is applicable to the 33 coating of any conductive substrate and especially metal such as steel, al~ ~ , copper and the like. After deposition, the coating 35 is cured at elevated temperatures by any convenient method such as in 1 baking ovens or with banks of infra-red heat lamps. Curing temperatures of 200-400F. (93-204C.) and curing times of 10 to 60 3 minutes are typical.
Illustrating the invention are the following examples which 5 are not to be construed as limiting the invention to their details.
All parts and percentages in the examples as well as throughout the 7 specification are by weight unless otherwise specified.
The following examples (I-IV) show the formulation of 11 various cationic electrodeposition paints containing lead pigment and carbon black. Two paints (Examples I and III) were prepared using 13 the pigment grinding vehicle of the present invention (Example F) which contained both ternary sulfonium and quaternary ammonium salt 15 groups, and two paints (Examples II and IV) were prepared using the pigment grinding vehicle of the prior art (Example E) which contained 17 only ternary sulfonium groups. The paints were evaluated for pump stability and for stability against sedimenting.
19 In preparing the cationic electrodeposition paints, the following cationic resin, additive, pigment grinding vehicles, 21 pigment pastes and catalyst pastes were used.
23 ExamPle A
A cationic film-forming resin was prepared by reacting a 25 polyepoxide with N-methylethanolamine and the methyl isobutyl diketimine of diethylenetriamine. The reaction product was combined 27 with a fully blocked polyisocyanate and solubilized with acid as generally described in Example 2 of published European Application 236,050.
ADDITIVE
31 Example B
A polyoxyalkylenepolyamine-polyepoxide adduct having an 33 amine to epoxide equivalent ratio of 1.34/1 was prepared, solubilized with lactic acid and dispersed in water (solids content 38.7 percent) 35 as generally described in Example J of U.S. 4,615,779.
- 12 - l 3 3 6 2 1 6 PIGMENT GRINDING VEHICLE
Example C
A pigment grinding vehicle was prepared as generally described in Example M of U.S. Patent No. 4,615,779.
Example E
A pigment grinding vehicle was prepared by reacting a polyglycidyl ether of bisphenol A with nonyl phenol (1.9 percent by weight) and thiodiethanol and dimethylolpropionic acid (0.992 milliequivalents of sulfonium per gram of resin) as follows:
Parts by Weight Solids Ingredients (in grams) (in grams) Equivalents EPON* 8281 533.2 533.2 2.836 Bisphenol A 199.6 199.6 1.751 Nonyl phenol 19.2 19.2 0.086 Ethyltriphenyl phosphonium iodide 0.75 Monobutyl ether of propylene glycol 201.6 Thiodiethanol 122.1 122.1 1.0 Dimethylolpropionic acid 134.1 134.1 1.0 Deionized water 30.6 I Polyglycidyl ether of bisphenol A, available from Shell Chemical Co.
The EPON* 828, bisphenol A and nonyl phenol were charged to a reaction vessel and heated to 107C. and held at this temperature until the bisphenol A dissolves. The ethyltriphenyl phosphonium iodide was then added and the reaction mixture heated to 125C. to initiate an exotherm. The reaction mixture was m~int~ined at exotherm for about one hour until a viscosity of P (measured as a 50 percent resin solids solution in 2-methoxypropanol, DOWANOL* PM) was obtained (epoxy equivalent weight of about 763). The reaction mixture was cooled to 75C. followed by the addition of the monobutyl ether of propylene glycol, thiodiethanol, dimethylolpropionic acid and water.
The reaction mixture was heated to 70-75C. and held at *Trade-mark y \
- 13 - I 3 3 6 2 1 ~
1 this temperature until an acid value of 3.36 was obtained. The reaction mixture was then cooled and thinned with additional water to 3 a solids content of 36.2 percent.
ExamPle F
A pigment grinding vehicle similar to Example E was 7 prepared but in which the polyglycidyl ether of bisphenol A was reacted with a mixture of thiodiethanol and dimethylethanolamine to 9 form a vehicle containing both ternary sulfonium and quaternary ammonium groups.
11 Parts by Weight Solids In~redients (in ~rams) (in ~rams) Equivalents 13 EPON 828 533.2 533.2 2.836 Bisphenol A 199.6 199.6 1.751 15 Nonyl phenol 19.2 19.2 0.086 Ethyltriphenyl 17 phosphonium iodide 0.5 - -Monobutyl ether of 19 propylene glycol 200.5 Sulfide-amine mixturel177.3 146.7 0.785 (sulfide) 21 0.215 (amine) 0.237 (acid) 23 Dimethylolpropionic acid 102.3 102.3 0.763 lThe sulfide-amine mixture was prepared from the following 25 ingredients:
Parts by Weight Solids 27 In~redients (in ~rams) (in ~rams) Equi'valents Thiodiethanol 287.4 287.4 2.355 29 Dimethylethanolamine57.6 57.6 0.645 Dimethylolpropionic acid 95.1 95.1 0.710 31 Deionized water 91.8 The thiodiethanol and dimethylethanolamine were charged to a reaction 33 vessel and mixed. Dimethylolpropionic acid and water were then added and the mixture stirred at 60C. until a solution was obtained.
` -t336216 1 The EPON 828, bisphenol A and nonyl phenol were charged to a reaction vessel and heated to 107C. and held at this temperature 3 until the bisphenol A dissolves. The ethyltriphenyl phosphonium iodide was then added and the reaction mixture heated to 125C. to 5 initiate an exotherm. The reaction mixture was maintained at exotherm for about one hour until a viscosity of P (50 percent in 7 DOWANOL PM, epoxy equivalent of 775) was achieved. After addition of the monobutyl ether of propylene glycol, sulfide-amine mixture and 9 dimethylolpropionic acid, the reactants were heated to 70-75C.
until an acid value of 5.61 was obtained. The reaction mixture was 11 cooled and thinned with deionized water to a solids content of 32.1 percent.
CATALYST PASTE
ExamPle G
Dibutyltin oxide catalyst was dispersed in the grinding 17 vehicle prepared as described above in Example C in the following charge ratio:
19 In~redients Parts bv Wei~ht Quaternary ammonium salt group-21 cont~nlng pigment grinding vehicle prepared as described in Example C 145 23 Deioni~ed water 321.6 Dibutyltin oxide 200 The above ingredients were mixed together and ground in a mill to a Hegman No. 7 grind.
ExamPle H
29 Dibutyltin oxide catalyst was dispersed in the grinding vehicle prepared as described above in Example E in the following 31 charge ratio:
1 In~redients Parts by Wei~ht (in ~rams) Ternary sulfonium salt group-3 containing pigment grinding vehicle prepared as described above in Example E 735.2 SURFYNOL* 104El 2.25 7 Deionized water 340.7 Dibutyltin oxide 562.5 9 lAcetylenic alcohol available from Air Products and Chemicals Inc.
11 The above ingredients were mixed together and ground in a sand mill for 3 hours to a Hegman No. 7 grind.
ExamPle J
Dibutyltin oxide catalyst was dispersed in the grinding vehicle prepared as descrlbed above in Example F in the following 17 charge ratio:
In~redients Parts by Wei~ht (in ~rams) 19 Mixed quaternary ammonium-ternary sulfonium salt group-containing 21 pigment grinding vehicle prepared as described above in Example F 732.9 23 Deionized water 363.2 Dibutyltin oxide 500.0 The above ingredients were mixed together and ground in a sand mill for 3 hours to a Hegman No. 7 grind.
PIGMENT PASTE
29 Example K
A pigment paste was prepared by dispersing clay, titanium 31 dioxide and lead silicate in the pigment grinding vehicle of Example E as follows:
33 Ingredients Parts bY Wei~ht ~in ~rams) Pigment grinding vehicle of Example E 498.0 Catalyst paste of Example H 116.4 Deionized water 206.4 37 Clay 16.8 Titanium dioxide 701.0 39 Lead silicate 61.4 * Trade-mark ~1. .f ~
1 The above ingredients were ground together in a sand mill for 45 minutes to a Hegman No. 7 grind.
ExamDle L
A pigment paste was prepared by dispersing clay, titanium dioxide and lead silicate in the pigment grinding vehicle of Example 7 F as follows:
In~redients Parts bY Wei~ht (in ~rams) 9 Pigment grinding vehicle of Example F 482.3 Deionized water 222.1 11 Catalyst pacte 116.4 Clay 16.8 13 Titanium dioxide 701.0 Lead silicate 61.4 The ingredients were ground together in a sand mill for 45 minutes to a Hegman No. 7 grind.
Exam~le M
19 A pigment paste was prepared by dispersing lead silicate, carbon black and titanium dioxide in a mixed pigment grinding vehicle 21 consisting of the pigment grinding vehicle of Example F and of Example C.
23 In~redients Parts bY Wei~ht (in ~rams) Pigment grinding vehicle of Example F 275.3 Deionized water 286.5 , Pigment grinding vehicle of Example C 177.9 27 Lead silicate 64.3 Carbon black 28.4 29 Titanium dioxide 848.3 Catalyst paste of Example G 179.3 31 The ingredients were ground together in a sand mill to a Hegman No. 7 grind.
1 3362 1 ~
1 ExamPle N
A pigment paste was prepared by dispersing lead silicate, 3 carbon black and titanium dioxide in a mixed pigment grinding vehicle consisting of the pigment grinding vehicle of Example E and of 5 Example C.
In~redients Parts bY Wei~ht (in ~rams) 7 Pigment grinding vehicle of Example E 270.1 Deionized water 291.7 9 Pigment grinding vehicle of Example C 177.9 Lead silicate 64.3 11 Carbon black 28.4 Titanium dioxide 848.3 13 Catalyst paste of Example G 179.3 The above ingredients were ground in a sand mill to a 15 Hegman No. 7 grind.
The pigment grinding vehicle prepared as described 17 immediately above (500.1 grams) was mixed with an additional 8 grams of deionized water to form the final pigment paste.
PAINTS
21 ExamPle I
A cationic electrodeposition paint was prepared by mixing 23 together the following ingredients in the order indicated in a one gallon paint can under agitation from an overhead stirrer:
In~redients Parts by WeiRht (in ~rams) Cationic resin of Example A1457.6 27 Additive of Example B 160.5 Plasticizerl 37.9 29 Deionized water 1751.9 Pigment paste of Example K392.1 31 lPropoxylated cresol available from Rohm and Haas Co. as WP 1.
The paint formulated as described above was tested for pump 33 stability and resistance to sedimentation. The results are reported in the table below.
- 18 - 13~6216 1 Example II
A cationic electrodeposition paint was prepared as 3 generally described in Example I from the following ingredients:
In~redientsParts bY Wei~ht (in ~rams) Cationic resin of Example A 1457.3 Additive of Example B160.5 7 Plasticizer of Example I37.9 Deionized water 1749.4 9 Pigment paste of Example L 394.4 11 ExamPle III
A cationic electrodeposition paint was prepared as 13 generally described above in Example I from the following ingredients:
In~redients Parts bY Wei~ht (in ~rams~
Cationic resin of Example A 1328.8 Additive of Example B 146.3 17 Plasticizer of Example I 34.5 Deionized water 1942.3 19 Pigment paste of Example M 348.1 The cationic electrodeposition paint was passed through an 21 ultrafilter to the extent of 20 percent of its volume. The ultrafiltrate was replaced with deionized water. Phosphated 23 (BONDERITE* 40) steel panels were cathodically electrodeposited in the paint at a voltage of 275 volts for 2 minutes at a bath temperature 25 of 83F. (28C.) to form a continuous film. The paint was tested for pump stability and for resistance to sedimentation. The results are 27 reported in the table below.
29 Example IV
A cationic electrodeposition paint was prepared as 31 generally described above in Example I as follows:
In~redientsParts by Wei~ht (in ~rams~
33 Cationic resin of Example A 1328.9 Additive of Example B146.3 Plasticizer of Example I34.5 Deionized water 1983.7 37 Pigment paste of Example N 342.6 *Trade-mark 1 3 3 6 2 1 b 1 The paint was passed through an ultrafilter to 20 percent of its initial volume and the ultrafiltrate replaced with deionized 3 water. Phosphated steel panels were cathodically electrodeposited in the bath at 275 volts for 2 minutes at a bath temperature of 83F.
5 (28C.) to form a continuous film. The paint was tested for pump stability and for resistance to sedimentation. The results are 7 reported in the table below.
TABLE
9Pump Stability and Resistance to Sedimentation 11of Paints of ExamPles I-IV
Pigment Pigment 13 Paint Grinding Grinding Pump Example Vehicle Vehicle Stabilityl Sedimentation 15 No. (Exam~le~ (Ty~e~ (~rams~ Ratin~2 _ 17 I E ternary sulfonium 5.2 0/0 19 II F mixed ternary 2.2 5/8 sulfonium-quaternary 21 ammonium 23 III F+C mixed sulfonium- 0.3 9-3/4 / 10 quaternary ammonium + quaternary ammonium 27 IV E+C ternary sulfonium + 5.9 2/0 quaternary ammonium lThe pump stability is a measure of the resistance of the 31 paint to shearing forces. The pump stability was determined by recirculating one gallon of paint in a centrifugal pump (Little Giant 33 4MD) for 8 hours at a paint temperature of 90F. (32C.). The pigment pastes used in formulating the paints were heat aged for 3 35 days at 140F. (60C.) prior to formulation. The paint is then passed through a 200-mesh screen and the grams of sludge collected on 37 the screen is weighed and reported. The lower the amount of sludge collected, the greater the pump stability.
39 2The sedimentation rating is a measure of the sedimenting tendency of the paint and the ease of reincorporating the sediment 41 back into the paint. The pigment pastes used in formulating the paints were heat aged for 3 days at 140F. (60C.) prior to -- 20 - ~ 336216 1 formulation. In determining the sedimentation rating, a sample of the paint is placed in a 4-ounce glass ~ar and allowed to stand at 3 room temperature for 7 hours. The jar is then placed in an oven at 140F. (60C.) for 8 hours. The ~ar is then removed from the oven, 5 allowed to cool at room temperature and placed upside down in a Burell Model 75 wrist action shaker. Shaking is continued for 30 7 minutes. The reincorporation of sediment back into the paint is evaluated and given a first rating. The jar is removed from the 9 shaker and the bottom of the jar scraped thoroughly with a spatula.
The ~ar is shaken an additional 30 minutes, removed from the shaker 11 and allowed to stand in an upright position for an additional 10 minutes. The reincorporation of the sediment back into the paint is 13 given a second rating. A value of 10 is rated as excellent and 0 is rated very poor.
Claims (15)
1. A pigment paste suitable for cationic electrodeposition comprising:
(a) a cationic resinous grinding vehicle derived from an epoxy resin and containing salt groups comprising both quaternary ammonium and ternary sulfonium salt groups whereby said cationic resinous grinding vehicle is formed by simultaneously treating the epoxy resin with an acidified sulfide amine mixture, (b) a pigment component dispersed in the grinding vehicle, said pigment component containing a lead-containing pigment;
the pigment component to resin solids weight ratio being at least 2:1.
(a) a cationic resinous grinding vehicle derived from an epoxy resin and containing salt groups comprising both quaternary ammonium and ternary sulfonium salt groups whereby said cationic resinous grinding vehicle is formed by simultaneously treating the epoxy resin with an acidified sulfide amine mixture, (b) a pigment component dispersed in the grinding vehicle, said pigment component containing a lead-containing pigment;
the pigment component to resin solids weight ratio being at least 2:1.
2. The pigment paste of Claim 1 in which the epoxy resin is a polyglycidyl ether of a polyphenol.
3. The pigment paste of Claim 1 which contains from 0.05 to 1.20 milliequivalents of quaternary ammonium salt groups and 0.20 to 1.35 milliequivalents of ternary sulfonium salt groups per gram of resin solids.
4. The pigment paste of Claim 1 in which the lead-containing pigment is basic lead silicate.
5. The pigment paste of Claim 4 in which the lead-containing pigment is present in the pigment paste in amounts of 0.01 to 5.0 percent by weight based on total pigment paste solids.
6. The pigment paste of Claim 1 in which the pigment composition additionally contains carbon black.
7. The pigment paste of Claim 6 in which the carbon black is present in amounts of 0.01 to 5.0 percent by weight based on total paste solids.
8. The pigment paste of Claim 1 in which the pigment component to cationic resinous grinding vehicle solids weight ratio is from 2 to 7:1.
9. A cationic electrodeposition paint comprising a film-forming cationic electrodepositable resin, a pigment and a pigment grinding vehicle, said paint containing lead, characterized in that the pigment grinding vehicle is a cationic resin derived from an epoxy resin and containing salt groups comprising both quaternary ammonium and ternary sulfonium salt groups whereby said cationic resin is formed by simultaneously treating the epoxy resin with an acidified sulfide amine mixture.
10. The cationic paint of Claim 9 which contains from 200 to 5000 parts per million lead based on total paint weight.
11. The cationic paint of Claim 9 in which the epoxy resin is a polyglycidyl ether of a polyphenol.
12. The cationic paint of Claim 9 in which the pigment grinding vehicle contains from 0.05 to 1.20 milliequivalents of quaternary ammonium salt group and from 0.20 to 1.35 milliequivalents of ternary sulfonium salt group per gram of pigment grinding vehicle solids.
13. A method of coating an electrically conductive substrate serving as a cathode in an electrical circuit comprising said cathode and an anode in an aqueous electrodeposition paint by passing electric current between said cathode and said anode to cause the paint to deposit on the cathode; said aqueous electrodeposition paint being that in accordance with Claim 9.
14. The method of Claim 13 in which the aqueous electrodepositable paint is that of Claim 10.
15. The method of Claim 13 in which the aqueous electrodepositable paint is that of Claim 12.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17719488A | 1988-04-04 | 1988-04-04 | |
| US07/177,194 | 1988-04-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1336216C true CA1336216C (en) | 1995-07-04 |
Family
ID=22647593
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000595208A Expired - Fee Related CA1336216C (en) | 1988-04-04 | 1989-03-30 | Pigment grinding vehicles containing quaternary ammonium and ternary sulfonium groups |
Country Status (11)
| Country | Link |
|---|---|
| US (1) | US5130004A (en) |
| EP (1) | EP0336599B1 (en) |
| JP (1) | JPH0692554B2 (en) |
| KR (1) | KR930004697B1 (en) |
| AR (1) | AR246545A1 (en) |
| AU (1) | AU594259B2 (en) |
| BR (1) | BR8901553A (en) |
| CA (1) | CA1336216C (en) |
| DE (1) | DE68903592T2 (en) |
| ES (1) | ES2052904T3 (en) |
| ZA (1) | ZA891937B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE110096T1 (en) * | 1989-01-31 | 1994-09-15 | Basf Corp | HYDROFOBIC CATHODICALLY DEPOSIBLE ELECTROCOAT DYES. |
| DE69226777T2 (en) * | 1991-06-27 | 1999-04-29 | Basf Corp | METHOD FOR PRODUCING AN ELECTRO DIP PAINT COMPOSITION CONTAINING A SOLID PIGMENT DISPERSION |
| US5323054A (en) * | 1991-07-01 | 1994-06-21 | Matsushita Electric Industrial Co., Ltd. | Semiconductor device including integrated injection logic and vertical NPN and PNP transistors |
| KR950011017B1 (en) * | 1991-07-01 | 1995-09-27 | 미쯔시다덴기산교 가부시기가이샤 | Semiconductor device and its making method |
| DE4133853A1 (en) * | 1991-10-12 | 1993-04-15 | Basf Lacke & Farben | SYNTHETIC RESINS |
| CZ282509B6 (en) * | 1992-05-29 | 1997-07-16 | Vianova Resins Aktiengesellschaft | Catalytic, cationic binding agent of a varnish and process for preparing thereof |
| US5358884A (en) * | 1992-09-11 | 1994-10-25 | Micron Technology, Inc. | Dual purpose collector contact and isolation scheme for advanced bicmos processes |
| AT398987B (en) * | 1993-09-07 | 1995-02-27 | Vianova Kunstharz Ag | METHOD FOR THE PRODUCTION OF PREPARATIONS CONTAINING BISMUTH SALTS AND THE USE THEREOF AS A CATALYST COMPONENT IN CATHODICALLY DEPOSIBLE ELECTRIC DIVERS |
| US5378762A (en) * | 1993-12-22 | 1995-01-03 | Basf Corporation | Polymeric pigment dispersants for use in coating compositions |
| IL116376A (en) * | 1994-12-15 | 2001-03-19 | Cabot Corp | Aqueous ink jet ink compositions containing modified carbon products |
| US5571311A (en) * | 1994-12-15 | 1996-11-05 | Cabot Corporation | Ink jet ink formulations containing carbon black products |
| US5575845A (en) * | 1994-12-15 | 1996-11-19 | Cabot Corporation | Carbon black products for coloring mineral binders |
| US5559169A (en) * | 1994-12-15 | 1996-09-24 | Cabot Corporation | EPDM, HNBR and Butyl rubber compositions containing carbon black products |
| US5554739A (en) * | 1994-12-15 | 1996-09-10 | Cabot Corporation | Process for preparing carbon materials with diazonium salts and resultant carbon products |
| US5807494A (en) | 1994-12-15 | 1998-09-15 | Boes; Ralph Ulrich | Gel compositions comprising silica and functionalized carbon products |
| IL116378A (en) * | 1994-12-15 | 2003-05-29 | Cabot Corp | Non-aqueous coating or ink composition with improved optical properties containing modified carbon product and method of preparation of the composition |
| IL116379A (en) * | 1994-12-15 | 2003-12-10 | Cabot Corp | Aqueous inks and coatings containing modified carbon products |
| IL116377A (en) | 1994-12-15 | 2003-05-29 | Cabot Corp | Reaction of carbon black with diazonium salts, resultant carbon black products and their uses |
| US5622557A (en) | 1995-05-22 | 1997-04-22 | Cabot Corporation | Mineral binders colored with silicon-containing carbon black |
| US6028137A (en) | 1995-05-22 | 2000-02-22 | Cabot Corporation | Elastomeric compounds incorporating silicon-treated carbon blacks |
| HUP9802554A3 (en) | 1995-05-22 | 1999-04-28 | Cabot Corp | Elastomeric compounds incorporating partially coated carbon blacks |
| US6323273B1 (en) | 1995-05-22 | 2001-11-27 | Cabot Corporation | Elastomeric compounds incorporating silicon-treated carbon blacks |
| US5958999A (en) | 1996-04-05 | 1999-09-28 | Cabot Corporation | Ink compositions and method for generating images produced therefrom |
| US5707432A (en) | 1996-06-14 | 1998-01-13 | Cabot Corporation | Modified carbon products and inks and coatings containing modified carbon products |
| US5747562A (en) | 1996-06-14 | 1998-05-05 | Cabot Corporation | Ink and coating compositions containing silicon-treated carbon black |
| US5698016A (en) * | 1996-06-14 | 1997-12-16 | Cabot Corporation | Compositions of modified carbon products and amphiphilic ions and methods of using the same |
| US5908912A (en) * | 1996-09-06 | 1999-06-01 | Ppg Industries Ohio, Inc. | Electrodepositable coating composition containing bismuth and amino acid materials and electrodeposition method |
| US5919855A (en) | 1997-02-11 | 1999-07-06 | Cabot Corporation | Use of modified carbon black in gas-phase polymerizations |
| US6423425B1 (en) | 1998-05-26 | 2002-07-23 | Ppg Industries Ohio, Inc. | Article having a chip-resistant electrodeposited coating and a process for forming an electrodeposited coating |
| US6248225B1 (en) | 1998-05-26 | 2001-06-19 | Ppg Industries Ohio, Inc. | Process for forming a two-coat electrodeposited composite coating the composite coating and chip resistant electrodeposited coating composition |
| KR100891156B1 (en) * | 2007-01-16 | 2009-04-06 | 주식회사 케이씨씨 | A cationic pigment grinding resin and an electrodepositable coating composition comprising the same |
| JP5007979B2 (en) | 2008-05-22 | 2012-08-22 | 独立行政法人産業技術総合研究所 | Defect inspection method and defect inspection apparatus |
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|---|---|---|---|---|
| US3793278A (en) * | 1972-03-10 | 1974-02-19 | Ppg Industries Inc | Method of preparing sulfonium group containing compositions |
| US3936405A (en) * | 1972-08-16 | 1976-02-03 | Ppg Industries, Inc. | Novel pigment grinding vehicles |
| US3959106A (en) * | 1974-03-27 | 1976-05-25 | Ppg Industries, Inc. | Method of electrodepositing quaternary sulfonium group-containing resins |
| US4097352A (en) * | 1975-07-08 | 1978-06-27 | Ppg Industries, Inc. | Electrodeposition of compositions containing sulfonium resins and capped polyisocyanates |
| US4186124A (en) * | 1975-08-01 | 1980-01-29 | Ppg Industries, Inc. | Novel pigment grinding vehicle |
| US4007154A (en) * | 1975-08-01 | 1977-02-08 | Ppg Industries, Inc. | Novel pigment paste for cationic electrodeposition |
| US4066523A (en) * | 1976-02-17 | 1978-01-03 | Scm Corporation | Dual cure cathodic electrocoating composition |
| US4035273A (en) * | 1976-05-24 | 1977-07-12 | Scm Corporation | Cathodic electrocoating process |
| US4260716A (en) * | 1979-05-07 | 1981-04-07 | Ppg Industries, Inc. | Polymeric quaternary ammonium hydroxides and their use in coating applications |
| US4292155A (en) * | 1979-10-31 | 1981-09-29 | Ppg Industries, Inc. | Cationic electrodeposition employing novel mercapto chain extended products |
| US4468307A (en) * | 1981-09-14 | 1984-08-28 | Ppg Industries, Inc. | Method of cationic electrodeposition |
| US4485259A (en) * | 1982-09-30 | 1984-11-27 | Ppg Industries, Inc. | Pigment grinding vehicle |
| AU547702B2 (en) * | 1982-09-30 | 1985-10-31 | Ppg Industries, Inc. | Amine modified epoxy |
| JPS61235476A (en) * | 1985-04-10 | 1986-10-20 | Nippon Paint Co Ltd | Cationic electrodeposition paint composition |
| DE3518770A1 (en) * | 1985-05-24 | 1986-11-27 | BASF Lacke + Farben AG, 4400 Münster | WATER-DISCOVERABLE BINDING AGENTS FOR CATIONIC ELECTRO-DIP COATINGS AND METHOD FOR THEIR PRODUCTION |
| DE3518732A1 (en) * | 1985-05-24 | 1986-11-27 | BASF Lacke + Farben AG, 4400 Münster | WATER-DISCOVERABLE BINDING AGENTS FOR CATIONIC ELECTRO-DIP COATINGS AND METHOD FOR THEIR PRODUCTION |
| DE3530179A1 (en) * | 1985-08-23 | 1987-02-26 | Herberts Gmbh | CATHODICALLY DEPOSITABLE AQUEOUS ELECTRODESCENT COATING AGENT |
| US4715898A (en) * | 1986-06-30 | 1987-12-29 | Ppg Industries, Inc. | Sulfonium resins useful as pigment grinding vehicles in cationic electrodeposition |
-
1989
- 1989-03-14 ZA ZA891937A patent/ZA891937B/en unknown
- 1989-03-21 DE DE8989302768T patent/DE68903592T2/en not_active Expired - Fee Related
- 1989-03-21 EP EP89302768A patent/EP0336599B1/en not_active Expired - Lifetime
- 1989-03-21 ES ES89302768T patent/ES2052904T3/en not_active Expired - Lifetime
- 1989-03-30 CA CA000595208A patent/CA1336216C/en not_active Expired - Fee Related
- 1989-04-03 BR BR898901553A patent/BR8901553A/en not_active IP Right Cessation
- 1989-04-03 AR AR89313567A patent/AR246545A1/en active
- 1989-04-03 AU AU32355/89A patent/AU594259B2/en not_active Ceased
- 1989-04-03 KR KR1019890004355A patent/KR930004697B1/en not_active IP Right Cessation
- 1989-04-04 JP JP1085631A patent/JPH0692554B2/en not_active Expired - Fee Related
-
1990
- 1990-02-20 US US07/481,812 patent/US5130004A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| BR8901553A (en) | 1989-11-14 |
| AU594259B2 (en) | 1990-03-01 |
| DE68903592D1 (en) | 1993-01-07 |
| ES2052904T3 (en) | 1994-07-16 |
| JPH0211668A (en) | 1990-01-16 |
| AR246545A1 (en) | 1994-08-31 |
| EP0336599A3 (en) | 1991-03-06 |
| ZA891937B (en) | 1990-11-28 |
| DE68903592T2 (en) | 1993-04-08 |
| KR930004697B1 (en) | 1993-06-03 |
| EP0336599B1 (en) | 1992-11-25 |
| JPH0692554B2 (en) | 1994-11-16 |
| EP0336599A2 (en) | 1989-10-11 |
| US5130004A (en) | 1992-07-14 |
| KR890016134A (en) | 1989-11-28 |
| AU3235589A (en) | 1989-11-23 |
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