CA1184334A - Aqueous polyisocyanate emulsions useful as binders in the production of molded articles - Google Patents
Aqueous polyisocyanate emulsions useful as binders in the production of molded articlesInfo
- Publication number
- CA1184334A CA1184334A CA000418781A CA418781A CA1184334A CA 1184334 A CA1184334 A CA 1184334A CA 000418781 A CA000418781 A CA 000418781A CA 418781 A CA418781 A CA 418781A CA 1184334 A CA1184334 A CA 1184334A
- Authority
- CA
- Canada
- Prior art keywords
- emulsion
- diaminodiphenylmethane
- isocyanate
- polyisocyanate
- formaldehyde resin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L75/00—Compositions of polyureas or polyurethanes; Compositions of derivatives of such polymers
-
- 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
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/703—Isocyanates or isothiocyanates transformed in a latent form by physical means
- C08G18/705—Dispersions of isocyanates or isothiocyanates in a liquid medium
- C08G18/706—Dispersions of isocyanates or isothiocyanates in a liquid medium the liquid medium being water
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L97/00—Compositions of lignin-containing materials
- C08L97/02—Lignocellulosic material, e.g. wood, straw or bagasse
-
- 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
- C08G2125/00—Compositions for processes using internal mould release agents
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Dispersion Chemistry (AREA)
- Wood Science & Technology (AREA)
- Materials Engineering (AREA)
- Polyurethanes Or Polyureas (AREA)
- Dry Formation Of Fiberboard And The Like (AREA)
- Paints Or Removers (AREA)
- Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Aqueous polyisocyanate emulsions are made by emulsifying 5 to 70 parts by weight (on a basis of 100 parts) of a polyisocyanate which has not been modified to render it hydrophilic and emulsifiable with 30 to 95 parts by weight (on a basis of 100 parts) aqueous paraffin dispersion known additives in the presence of water. The water is used in a quantity such that the emulsion has a solids content of from 6 to 90 wt. %.
These emulsions are particularly useful as binders in the production of molded articles.
Aqueous polyisocyanate emulsions are made by emulsifying 5 to 70 parts by weight (on a basis of 100 parts) of a polyisocyanate which has not been modified to render it hydrophilic and emulsifiable with 30 to 95 parts by weight (on a basis of 100 parts) aqueous paraffin dispersion known additives in the presence of water. The water is used in a quantity such that the emulsion has a solids content of from 6 to 90 wt. %.
These emulsions are particularly useful as binders in the production of molded articles.
Description
9L33~
~10-2431 LeA 21,525 AQUEOUS P~LYISOCYANAi~E E~LSIONS Us~FrJL AS
BIMDERS IN THE PROD~CTION OF MOLDED ARTICLES
BACKGRO~ND OF THE INVENTION
This invention relates to aqueous poly-isocyanate emulsions useful as binders in thepro~luctLon of molded articles, particularly boards OI
materials containing lignocellulose.
Mold~d articles such as chipboard, composite board and the like are generally produced by hot molding an inorganic or organic raw material (e~g. a mass of wood shavings, wood fibers or oth~r material containing lignocellulose) together with binders (e.g.
aqueous dispersions or solutions of urea formaldehyde or phenol formaldehyde resins). It is known to use isocyanate solutions instead of urea formaldehyde or phenol formaldeh~de resins as binders for molded board (German Auslegeschrift 1,271,984, German Offenlegungs-schrift 1,653,177).
In these hot molding processes (particularly in the manufacture of wood chipboards) it is generally necessary under the standard regulations of the building trade (e.g. DIN 68 763) to add hydro-plloblcizing agents separately. In practice, such agents are usually in the form of aqueous paraffin di5persions because it is believed to be impossible to mix these agents with unmodified polyisocyanates ; (Sachs, 1977, Molz-Zentralblatt No. 20, page 295/296;
Ball/Redman, 1979, Holz-Zentralblatt No~ 88, page 1291). Use of isocyanates or the manufacture of chipboard is thereby rendered much more difficult.
Another known yrocess for the manufacture of boar~s or molded artlcles is hot rnolding a tnixture of LeA 21 525 -US
lignocellulose material and an aqueous emulsion of an organic polyisecyanate as binder (German OEfen-legun(~sschriften 2,610,552 and 2,703,271). In this process, the aqueous paraffin dispersions reqllired for the manufacturQ of wood chipboard may be applied separately or in admixture with a previously prepared aqueous isocyanate emulsion (Ball/Redman 1979, Holz-Zentralblatt No. 88~ page 1291; German Offenlegungs-schrift 2~948~015)o However, these aqueous emulsions have the serious disadvantage that expensive isocyanate modification processes are required to render the emulsion hydrophilic and emulsifiable. In some cases the necessary emulsifiers are expensive and they incxease the cost of the binders by 20 to 30% making such lsocyanate binders less competitive economically with conventional binders. Additionally, isocyanates which have been modified to render thern emulsifiable (see German Ausle~eschriften 2,921,681; 2,921,726,
~10-2431 LeA 21,525 AQUEOUS P~LYISOCYANAi~E E~LSIONS Us~FrJL AS
BIMDERS IN THE PROD~CTION OF MOLDED ARTICLES
BACKGRO~ND OF THE INVENTION
This invention relates to aqueous poly-isocyanate emulsions useful as binders in thepro~luctLon of molded articles, particularly boards OI
materials containing lignocellulose.
Mold~d articles such as chipboard, composite board and the like are generally produced by hot molding an inorganic or organic raw material (e~g. a mass of wood shavings, wood fibers or oth~r material containing lignocellulose) together with binders (e.g.
aqueous dispersions or solutions of urea formaldehyde or phenol formaldehyde resins). It is known to use isocyanate solutions instead of urea formaldehyde or phenol formaldeh~de resins as binders for molded board (German Auslegeschrift 1,271,984, German Offenlegungs-schrift 1,653,177).
In these hot molding processes (particularly in the manufacture of wood chipboards) it is generally necessary under the standard regulations of the building trade (e.g. DIN 68 763) to add hydro-plloblcizing agents separately. In practice, such agents are usually in the form of aqueous paraffin di5persions because it is believed to be impossible to mix these agents with unmodified polyisocyanates ; (Sachs, 1977, Molz-Zentralblatt No. 20, page 295/296;
Ball/Redman, 1979, Holz-Zentralblatt No~ 88, page 1291). Use of isocyanates or the manufacture of chipboard is thereby rendered much more difficult.
Another known yrocess for the manufacture of boar~s or molded artlcles is hot rnolding a tnixture of LeA 21 525 -US
lignocellulose material and an aqueous emulsion of an organic polyisecyanate as binder (German OEfen-legun(~sschriften 2,610,552 and 2,703,271). In this process, the aqueous paraffin dispersions reqllired for the manufacturQ of wood chipboard may be applied separately or in admixture with a previously prepared aqueous isocyanate emulsion (Ball/Redman 1979, Holz-Zentralblatt No. 88~ page 1291; German Offenlegungs-schrift 2~948~015)o However, these aqueous emulsions have the serious disadvantage that expensive isocyanate modification processes are required to render the emulsion hydrophilic and emulsifiable. In some cases the necessary emulsifiers are expensive and they incxease the cost of the binders by 20 to 30% making such lsocyanate binders less competitive economically with conventional binders. Additionally, isocyanates which have been modified to render thern emulsifiable (see German Ausle~eschriften 2,921,681; 2,921,726,
2,610,552 and 2,703,271 and the literature cited therein) give rise to storage problems c.f both the products themselves and the glue-covered chips.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide aqueous polyisocyanate emulsions.
It is also an object of the present invention 2~ to provide aqueous emulsions of polyisocyanates which polyisocyanates have not been hydrophilically modified.
It is another object of the pxesent invention to provide aqueous ernulsions useful in the production of molded articles by hot rnolding processes.
It ls yet another object of the present invention to provide an aqueous emulsion which is Mo-2431
SUMMARY OF THE INVENTION
It is an object of the present invention to provide aqueous polyisocyanate emulsions.
It is also an object of the present invention 2~ to provide aqueous emulsions of polyisocyanates which polyisocyanates have not been hydrophilically modified.
It is another object of the pxesent invention to provide aqueous ernulsions useful in the production of molded articles by hot rnolding processes.
It ls yet another object of the present invention to provide an aqueous emulsion which is Mo-2431
3~
simple to ~ake and use, 'nas reduced reactivit,y with water and is economical.
These a~d other objects which will ~e appar2n~
to those skilled ln t'ne art are accomplished by a,~
aqueous emulsion made from a~ 5-70 parts by weight emulsifier-free pol~,7isocyanate which polyisocyanate has not been modified to render it hydrophills and emulsifiable and b) 30-95 parts by ~Jeig'nt aqueous paraffin dispersion having a paraffin content of from 3 to 65 wt. % in a quantity of water such that the emulsion has a solids content of from 6 to 90 wt. ~.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to aqueous emulsions of organic polyisocyanates, aqueous paraffin dispersions and optionally additional water. These emulsions are made by emulsifyiny a) from 5 to 70 parts by weight ~preferably from 10 to 60 parts by weight) of an emulsifier-free polyisocyanate which has not been modified to render it hydrophilic and emulsifiable and b) from 30 to 95 parts by weight ~preferably from 40 to 30 parts by welgh-t), of an aqueous paraffin dispersion containing from 3 to 65 wt.
% of paraffin, and optionally the usual additives in the usual quantities in water without the addition of emulsifier. The quantity of water employed is calculated to provide an emulsion having a solids content (composed of a) plus b)) of from 6 to 90 wt. %, preferably from 10 to 70 wt. %.
The present invention also relates to the use of these polyisocyanate emulsions as binders in the production of molded articles by 'not molding a mass of size reduced organic and/or inorganic raw materials.
~o-2431 33~
mhe emulsions of the present invention may be prepared, for example, by mixing the polyisocyanate with the paraffin disp2rsion, optionally further diluted with water.
Examples of suitable paraffin dispersions include the dispersions obtalned according to German Offenlegungsschrift 2,948,015 by the dispersion of paraffins in the presence of dispersing agents based on cationic polyelectrolytes. The dispersions disclosed in ~.S. Patents 2,655,496 and 3,965,032 or similar products of ~lobil Oil (such as Mobilcer-A-331 or Mobil Oil experimental product ED 80/196 (see G. W. Ball et al, Holz-Zentralblatt ~o. 88 of 23rd July, 1979; or ~.I. Sachs, Holz-~entralblatt 103, No. 20, pages 295-296, and No. 25, pages 384-388 (1977)) may also be used.
The aqueou.s emulsions may be produced in industrial plants by mixing the starting components in special mixing apparatus, such as static mixers;
stirrers with mixing heads; Inline-Ultra-Turrax apparatus (as ~abricated by Ja~ke und Kunkel, ~-7~12, Bad Krotzingen-2,)by high pressure mixIllg heads or high pressure inJection inoculation blocks.
The emulsions of the present invention may be prepared and processed either batchwise or continuously. Continuous processes are preferred due to their increased reliability in production.
The isocyanate components used in the preparation of the emulsions of the present invention may `~e aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates such as those described, for example, by W. Siefken in Justus Liehigs Annalen der Chemie, 562, pages 75 to 136. Suita~le isocyanates include those corresponding to the formula ~o-2431 3~
Q (NC~)n in which n ~epres~nts 2 to 4, preferably 2, and ~2 repr~sents an alip~atic hydroc~rbon group havlng 2 to 18 (preferably 6 to 10) carbon atoms, a cyclo-aliph~tic hydrocar~on group having 4 to 23 (preferably 5 to 13) carbon atoms, ~n aromatic hydrocarbon group havin~ 6 to 23 (preferably 6 to 13) carbon atomst or an araliphatic hydrocarbon group havin~ 8 to 15 (preferably 8 to 13~ carbon ato~s.
Specific examples of such isocyanates are: 1,4-tetra-methylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1,3-diiso-cyanate, cyclohexane-1,3- and -1,4-diisocyanate and mixtures of these isomers; l-isocyanato-3,3,S-tri-methyl-5-isocyanatomethyl-cyclohexane (DE-3 1,202~785, U.S. Patent 3,401,190), 2,4- and 2,6-hexanydro-tolylene diisocyanate and mixtures of these isomers;
hexahydro-1,3-- and/or 1,4-phenylene diisocyanate, perhydro-2,4'-- and/or 4,4'-dipIlenylmethane diisocyanat~, 1,3- and 1,4~phenylene diisocyanate, 2,4-and 2,6-tolylene diisocyanate and mixtures OL these isomers; diphenylmethane-2,4' and/or 4,4'-diisocyanate, and naphthylene-1,5-diisocyanate.
The following may also be used in the present invention: triphenylmethane.-4,4',4"-trilsocyanate;
polyphenyl-polymethylene-polyisocyanates which may be obtained by aniline-formaldehyde condensation followed by phosgenation (described, for example in ~ritish Patents 874,430 and 848,671); m- and p-isocyanatophenyl sulfonyl isocyanates (U.S. Patent 3,454,606);
Mo-2431 perchlorinated arylpolyisocyanates (described for example~ in German Auslegeschrift 1,157,601 (U.S.
Patent 3,277,138)); polyisocyanates containing carbo-diimide groups (described i.n German Patent 1,092,007 (U.S. Patent 3,152,162) and in German Offenlegungs-schriften 2,504,400, 2,537,685 and 2,552,350);
norbornane diisocyanates (U.S. Patent 3,~92,330); poly-isocyanates containing allophanate groups ~described in Bri~ish Patent 994,890, Belgian Patent 761,626 and Netherlands Patent Specification 7,102,524); polyiso-cyanates containing isocyanurate groups (described in U.S. Patent 3,001,973, German Patents 1,022,789;
1,222,067 and 1,027,394 and in German Offenlegungs-schriften 1,929,034 and 2,004,048); polyisocyanates con~aining urethane groups (described ln Belgian Patent 752,261 or in U.S. Patents 3 9 394,164 and 3,644,457);
polyisocyanates containing acylated urea groups (German Patent 1,230,778); polyisocyanates containing biuret groups (described in U.S. Patents 3,124,605; 3,201,372 and in British Patent 889,040); polyisocyanates prepared by telomerization reactions (U.S. Patent 3,654,106); polyisocyanates containing ester groups (British Patents 965,474 and 1,077,956, U.S. Patent 3~567,763 and German Patent 1,231,688); reaction products of the above-mentioned isocyanates with acetals (German Patent 1,072,385) and polyisocyanates containing polymeric fatty acid esters (U.S. Patent 3,455,883). Any mixture of the above-mentioned poly-isocyanates may also be used.
It is generally preferred to use the commercially readily availa.ble polyisocyanates, such as 2,4 and 2,6-tolylene diisocyanate and any mixtures of these isomers ("TDI"); polyphenyl polymethylene poly-Mo-2431 .~
~ 3 ~ ~
isocyanates as prepared by aniline-formaldehyde condensation followed by phosgenation ("crude MDI");
and polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups, biuret groups or other groups used in isocyanate chemistry ("modified polyisocyanates").
Those modified polyisocyanates which are derived from 2,4 and/or 2,6-tolylene diisocyanate or from 4,4'-and/or 2,4'- and/or 2,2'-diphenylmethane diisocyanate are particularly pre:Eerred.
Prepolymers with an average molecular weight of about 300 to 2000 containing isocyanate end groups, such as those obtained in known manner by reacting relatively high molecular weight and/or low molecular weight polyols with an excess of polyisocyanate, may also be used in preparing the emulsion o-f the present invention. Relatively high molecular weight polyols which are particularly suitable for making such prepolymers are compounds having from 2 to 8 hydroxyl groups, especially those with molecular weights from 400 to 10,000 (preferably from 800 to 5000). Such polyols include polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyester amides having at least two, generally two to eight, preferably two to four hydroxyl groups, which are known to be useful in the production of both homogeneous and cellular polyurethanes~
Suitable polyesters containing hydroxyl groups include the reaction products of polyhydric (preferably 30 dihydric) alcohols, optionally with the addition of trihydric alcohols, and polybasic (preferably dibasic) carboxylic acids. Instead o free polycarboxylic Mo-2431 ~r 3~
acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof may also be used in the preparation of the polyesters. The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and/or heterocyclic and they may be substituted (e.g. with halogen atoms), and/or unsaturated.
The following are specific examples of carboxylic acids and deri~atives which may be used to prepare the polyesters: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic acid anhydride, tetrahydrophthalic acid anhydride, hexa-hydrophthalic acid anhydride, tetrachlorophthalic acid anhydride, endomethylene tetrahydrophthalic acid anhydride, glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric acid, dimerized and trimerized unsaturated fatty acids optionally mixed with monomeric unsaturated fatty acids (such as oleic acid); dimethy:Lterephthalate and terephthalic acid-bis-glycol esters. Examples of suitable polyhydric alcohols include: ethylene glycol, (1,2)- and (1,3)-propylene glycol, (1,4)- and (2,3)-butylene glycol, (1,6)-hexanediol, (1,8) octanediol, neopentyl glycol, 1,4-bis-hydroxymethylcyclohexane, 2 methyl-1,3-propanediol, glycerol, trimethylolpropane, (1,2,6)-hexanetriol, (1,2,4)-butanetriol, trimethylolethane, pentaerythritol, quinitol, mannitol and sorbitol, formitol, methyl glycoside, di-, tri-, tetra- and 3~ higher polyethylene glycols, di-, tri-, tetra- and higher polypropylene glycols and di-, tri- and tetra-Mo-2431 ~r.r and higher polybutylene glycols. The polyesters may contain a proportion of carboxyl end groups.
Polyes~ers of lactones, e.g. of ~ -caprolactone, or of hydroxycarboxylic acids, e.g., of ~ -hydroxycaproic acid 7 may also be used.
The polyethers which may be used in the present in~ention contain at least two, generally two to eight, preferably two to three hydroxyl groups.
These polyethers may be prepared by the polymerization of epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin, either on their own in the presence of Lewis catalysts such as BF3, or by chemical addition of these epo~ides (preferably ethylene oxide and propylene oxide, optionally as mixtures or lS successively) to starting components which have reactive hydrogen atoms. Appropriate starting components are water, alcohols, ammonia or amines.
Specific e~amples of such starting components are ethylene glycol, (1 5 3)- or (1,2)-propylene glycol, trimethylolpropane, glycerol, sorbitol, 4,4'-dihydroxy-diphenylpropane, aniline, ethanolamine or ethylene diamine. Sucrose polyethers such as those described in German Auslegeschriften 1,176,358 and 1,064,938 and polyethers started on formi~ol or formose (German Offenlegungsschriften 2,639,083 and 2,737,951) may also be used. It is in many cases preferred to use polyethers containing predominantly primary O~ groups (up to 90% weight % thereof, based on all. the O~l groups present in the polyether). Polybutadienes containing OH groups are also suitable to the present invention.
Mo-2431 '~;.
33~
Suitable polythioethers include the condensation products of thiodiglycol obtained by reacting the ~hiodiglycol on its own and/or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amino alcohols. The products thus obtained may be, for example, mlxed polythio ethers, polythio ether esters, or polythio ethPr ester amides, depending upon the co-components.
Suitable polyacetals include those prepared from glycols such as diethylene glycol, triethylene glycol, 4,4'-dioxethoxydiphenyldimethylmethane, he~ane-diol and formaldehyde. Polyacetals suitable for purposes of the present invention may also be prepared by the polymerization of cyclic acetals such as trioxane (German Offenlegungsschrift 1,694,128).
The polycarbonates with hydroxyl groups which may be used in the present invention are known to those in the art. Such polycarbonates may be prepared, for example, by the reaction of diols such as (173)-propane diol, (1,4)-butanediol and/or (1,6)-hexanediol, di-, tri- or tetra-ethylene glycol or thiodiglycol with diarylcarbonates (e.g. diphenylcarbonate) or phosgene (German Auslegeschriften 1,694,080; 1,915,908 and 2,221,751 and German Offenlegungsschrift 2,605,024).
Polyester amides and polyamides which may be used in the practice of the present invention include e.g. the predominantly linear condensates ob~ained from polyvalent saturated or unsaturated carboxylic acids or their anhydrides and polyvalent saturated or unsaturated amino alcohols, diamines, polyamines or mixtures thereof.
Mo-2431 .. , ,. ~.
3~
Polyhydroxyl compounds which already con-tain urethane or urea groups and modlfied or unmodified natural polyols such as castor oil or carbohydrates (e.g. starch) may also be used in the present invention. Addition products of alkylene oxides with phenol formaldehyde resins or with urea formaldehyde resins are also suitable to the present invention.
Suitab]e low molecular weight polyols (molecular weight from 62 to 399) include, for example, the compounds mentioned above as starting components for the preparation of relatively high molecular weight polyols.
Catalysts may also be used in practicing the present invention. Suitable catalysts include those of known type such as tertiary amines. Specific examples of appropria~e catalysts are: trie~hylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, -cocomorpholine, N,N,N',N' tetramethyl-ethylene-diamine, 17 4-diaza-bicyclo-(2,2,2)-octane, N-methyl-N'~dimethyl-aminoethylpiperazine, N,N-dimethylbenzyl-amine, bis-(N,N diethylaminoethyl)-adipate, N,N-di-ethylbenzylamine, pentamethyl-diethylene-triamine, N,N-dimethylcyclohexylamine, N,N,NI,N'-tetramethyl-1,3-butane diamine, N,N-dimethyl- ~-phenylethylamine, 1,2-dimethylimidazole and 2-methylimidazole. The catalysts used may also be known Mannich bases oE
secondary amines such as dimethylamine and aldehydes tpreferably formaldehyde~ or ketones (such as acetone, methyl ethyl ketone or cyclohexanone), and phenols (such as phenol, nonylphenyl or bisphenol). Examples of other tertiary amines with isocyanate reactive hydrogen atoms used as catalyst include Mo-2431 33'~
triethanolamine, triisopropanolaminQ, N-methyldiethanolamine, N-ethyl-diethanolamine, N,N-dimethylethanolamine and their reaction products with alkylene oxides such as propylene oxide and/or ethylene oxide.
Silaamines having carbon-silicon bonds as described e~g. in German Patent 1,229,290 (corresponding to U.S. Patent 3,620,984) may also be used as catalys~. Specific examples of such compounds are 2,2,4-trimethyl-2-silamorpholine and 1,3-di-ethylaminomethyl-tetramethyl-disiloxane.
The catalysts used may also be bases containing ni~rogen (such as tetraalkylammonium hydroxides) or alkali metal hydroxides (such as sodium hydroxide), alkali metal phenolates (such as sodium phenolate) or alkali metal alcoholates (such as sodium methylate). Hexahydrotriazines may also be used as catalysts. Organic metal compounds, particularly organîc tin compounds may also be used as catalysts.
The preferred organic tin compounds are tin-(II) salts of carboxylic acids such as tin-(II) acetate, tin (II) octoate, tin-(II)-ethyl hexoate and tin-(II)-laurate and tin-(IV) compounds such as dibutyl tin oxide, dibutyl tin dichloride, dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin maleate and dioctyl tin diacetate. Mixtures of any of the above-mentioned catalysts may, of course, also be used.
Additional representatives of catalysts which may be used in the present invention and the mode of action of the catalysts are described in Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, e.g. on pages 96 to 102.
Mo-2431 '~
The emulsions of ~he present invention are preferably used as binders for materials containing lignocellulose. Emulsions which have proved particularly suitable for this purpose are those in which the polyisocyanate component is the phosgenation product of the undistilled ground fraction which may be obtained by the removal of 25 to 90 wt. % (preferably 30 to 98 wt. %) of 2,2', 2,4' andlor 4,4'-diamino-diphenylmethane from an aniline/formaldehyde condensate. Another particularly desirable polyisocyanate component is the undistilled ground fraction obtained by removal of from 25 to 90 wt. %
(preferably from 30 to 85 wt. %) of 2,2'-, 2,4'-and/or 4,4'-diisocyanatodiphenylmethane from the crude phosgenation product of an aniline/formaldehyde condensate. In either of these polyisocyanates, the isocyanate component should generally contain from 35 to 70 wt. % (preferably from 45 to 60 wt. %) o~
diisocyanatodiphenylmethane, the 2,4'-diisocyanato-diphenylmethane content should amount to from l to 8 wt. % (preferably from 2 to 5 wt. %) while the 212'-di-isocyanatodiphenylmethane content should preferably be from 0 to 2 wtn %. The isocyanate component should generally have a viscosity at 25C of from 50 to 600 mPas, (preferably from 200 to 500 mPas) and an isocyanate content of from 28 to 32 wt. % (see German Auslegeschrift 2 J 711,958).
Such ground fractions may be obtained, for example, when from 45 to 90 wt. % ~preferably from 55 to 85 wt. %) of 4,4'-diisocyanatodiphenylmethane is removed from a crude diphenylmethane diisocyanate containing more than 85 wt. % (preferably more than 90 Mo-2431 , t, :~
3~3~
ll~
wt. ~) of 4,4'-diisocyanatodiphenylmethane. A crude diphenylmethane diisocyanate of this kind may be obtained, for example, by the process according to German Of-fenlegungsschrift 2,356,828.
Another possible method for making suitable ground fractions is by distilling off 25 to 80 wt. %
(preferably 30 to 60 wt. %) of 2,4-diisocyanato-diphenylmethane and optionally 4,4'- or 2,2'-diiso-cyanatodiphenylmethane from a crude phosgenation product containing from 60 to 90 w~. % (preferably from 65 to 75 wt. %) of diisocyanatodiphenylmethane isomers and having from 20 to 60 wt. % (preferably from 30 to 40 wt. %) of 2,4'-isomers. Distillation may be carried out in a manner such that the residue has the composition indicated above.
I~ is of course possible (and in many cases simpler in practice) to obtain the desired composition of isomers and oligomers in the polyisocyanate mixture by blending various ground fractions.
In addition to the preferred unmodified poly-isocyanates, polyisocyanates modified to be self-releasing from the mold may also be mixed with the paraffin dispersions. Such polyisocyanates which have been modified to be self-releasing from the mold have been described, for example, in German Offenlegung-sschrift 3,109,317 (U.S. Patent 4,258,169), German Offenlegungsschrift 2,932,175 ~U.S. Patent 4,257,995) and U.S. Patent 4,257,996. These disclosed poly-isocyanates are modified with phosphorus compounds.
The modification of polyisocyanates with from 0.1 to 30 30 wt. % of phosphoric acid-Cl-C7-dialkylesters (preferably phosphoric acid-di-n-butylester) is Mo-2431 '~
known. In accordance with the present invention, these modified polyisocyanates are mixed with the paraffin dis-persion without the addition of emulsifier Suitable lignocellulose-containing raw materials which may be bound with the emulsions of the present inven-tion include wood, tree bark, cork, bagasse, straw, flax, bamboo, alfalfa grass, rice husks, sisal fibers and coconut fibers. These raw materials may be in the form of ~ranules, chips, fibers or powders and may have a water content of from 0 to 35 wt. % (preferably -from 5 to 25 wt. %). In accordance with the present invention, the binder is added to the lignocellulose-containing raw material in a quantity of from 1 to 100 wt. ~ (preferably from 2 to 12 wt. %3 and molded generally ~ith the appl i-- 15 cation of heat and pressure to ~orm boards or shaped products.
Molded products may, of course, also be pro-duced in accordance with the present invention from other organic (e.g. plastic waste of all kinds) and/or inorganic raw materials (e.g. expanded mica or silicate pellets).
When the emulsion of the present invention is used, the material which is to be molded is mixed with the binder, preferabIy by spraying it with the a~ueous emulsion in order to obtain very homogeneous distribu-tion. It has been found that the aqueous emulsions of the present invention have a sufficiently low viscosity to enable them to be sprayed even when they have an isocyanate content of up to 70%. The solwtions of urea/
formaldehyde and phenol/Eormaldehyde resins conventionally used in the manufacture o e molded Mo-243I
.i~
~'~..,i`P"
board and similar ma~erials can, however, generally be sprayed only i~ the solid content is below ~0%. The present invention thus provides a method in which less water is used than w~s previously possible so that less water need be removed during the stage of hot molding and/or subsequent conditioning. Further, the ligno-cellulose materials need not be dried as extensively before being mixed with the binder as is required in known processes.
Since the polyisocyanates employed in the present invention have not been modified to render them hydrophilic and they contain no added emulsifiers, the wood chip board obtained thererom has the lowest possible absorption of water so that the tendency to swell upon contact with water is significantly reduced.
Periods of delay may occur between the individual stages of the process (preparation o~ the emulsion, spraying oE the material to be used). Delays may a~so occur due to mechanical difficulties or the need to readjust the operating conditions. However, the reaction between the isocyanate and wa~er in the emulsions of the present invention proceed at a rate sufficiently slow to permit delays of 2 hours or more between preparation of the emulsion and hot molding without significantly affecting the product. The velocity of the reaction may be reduced by altering the reactivity of the polyisocyanates with water. The reaction velocity may, for example, be considerably reduced by increasing -the proportion of 2,l~'- and/or 2,2'-diphenylmethane diisocyanate.
Mo-2431 . .~ , .
3;~
~17-Multilayered boards or articles composed of veneers, pap~r or fabric may be produced in a manner analogous to that for the production of molded ~oard.
Mul-tilayered boards or shaped articles composed o~
veneers and middle layers of strips and bars or small rods, (so-called joiner boards) may be produced in accordance with the present invention by treating the veneers with the polylsocyana~e emulsions as described above and then pressing these veneers to the middle layers, generally at elevated temperatures and pressures. Temperatures of from 100 to 250~C are general]y advantageous in such treatments with temperatures from 130 to 220C being particularly useful. The initial molding pressure employed should preferably be from 5 to 150 bar with the pressure in most cases falling towards zero during the course of the molding process.
In accordance with the present invention, the polyisocyanate emulsions may also be used in combination with the polyhydroxyl compounds described above in an NCO/OH ratio ranging from 1-2 to 10:1, preferably from 1.5:1 to 1:1. The two components may be used either separately or as a reac~ive mixture.
Such combinations of polyisocyanates and polyhydroxyl compounds are of practical importance as binders, e.g.
for binding granulated cork. ~nown blowing agents may also be used in a quantity of ca. 0.5 to 30 wt. ~, based on the binder or impregnating agent. In addition or alternatively, additives which influence foaming or the chemical reaction between polyisocyanates, ligno-cellulose-containing material and, if used, polyhydroxyl compounds may also be employed. Examples Mo-2431 .~,...
'~
3 ~ 3~
of such additives are stabilizers, catalysts and activators. Such acldltives, if used, should generally be used in a quantity of from 0.05 to 10 wt. % based on the binder or impregnating agent.
The polyisocyanate emulsions to be used as binders in the practice of the present invention may also be combined with aqueous solutions of the condensation products of formaldehyde with urea and/or melamine and/or phenol, which have been used predominantly in the woodworking industry. The emulsions may also be combined with other less commonly used binders and impregnating agents, such as sulphite waste liquors (lignin sulphonate or other industrial llgnin solutions obtained from the processing of wood) or tanning substances (such as tannin), in a quantity such that the proportion of the binder of the present invention to the additional binders is in the range of from 1:10 to 10: 1 3 preferably from 1-5 to 5:1. The polyisocyanate emulsion and the additional binder may be used separately or as mixtures.
Such emulsion-binder combinations are particularly advantageous for the manufacture of multi-layered boards which have special properties. For example, the outer lay~rs may be treated with conventional adhesives (alone or together with the polyisocyanate emulsion of the present invention) while one or more inner layers are treated with the polyisocyanate emulsions of the present invention (alone or together with conventional adhesives) and the layers may subsequently be pressed together.
The boards or molded articles based on ligno-Mo-2431 ~,, O.~ .~, 3~
cellulose-containing other organlc and/or inorganic raw materials produced in accordance with the present invention are particularly suitable for use in the building industry because of their excellent mechanical properties. In order to impart to -these boards or molded articles the necessary resistance to mold, insects, or fire, the usual commercial additives (such as organic or inorganic protective agents) may be added to the binders or raw materials, either neat or as solutiolls. These additives are generally used in a quantity of about 0.05 to 30 wt. %, preferably 0.5 to 20 wt. %, base~ on the entire quantity of material.
Solvents which may be used in the present invention include water and organic solvents such as residual oils from the petroleum industry, chlorinated hydrocarbons, etc. These solvents generally do not impair adhesive quality. In contrast to boards glued with phenol/formaldehyde resin, the materials produced in accordance with the present invention have the advantage that neither efflorescence of salt nor "bleeding" occurs.
Due to the powerful adhesive force of the binders of the present invention, molded products impregnated or bonded with these binders have a tendency to adhere to the surfaces of the hot presses or molds. This problem may be avoi~ed by the addition of mold release agents to the isocyanate emulsions.
Another solution ~o the adhesive problem is application of the mold release agents either neat or as solutions to the metallic surfaces which come into contact with the moldings or to the surface of the molding. The mold release agen~s used may be any of the substances Mo-2431 known to be sui~able for this purpose although it is preferred to use the compounds according ~o German Offenlegungsschrift 2,325~926 which catalyze the formation of isocyanurates from isocyanates. Examples of such mold release agents include phenol Mannich bases, derivatives of hexahydrotriazine and alkali metal salts of carboxylic acids. Another method of preventing adherence to the surface of the molds is provision of a separating layer between the molding and the metallic surfaces of the mold. This separating layer may consist of webs, foils or size reduced material made of various substances (e.g. plastics, paper, wood or metal).
As mentioned above, the isocyanate emulsions of the present invention may provide substantial improvements in the manufacture of chipboard as compared to conventional binders based on phenol/formaldehyde or urea/formaldehyde resins, both in the mechanical properties of the product and with resp~ct to processing considerations. Thus, in the case of wood chipboard, when the binder of the present invention is used in the same quantity as the phenol/formaldehyde or urea/formaldehyde resins conventionally used may provide an increase in flexural strength by up to 50% (in addition to an improvement in other mechanical properties). The same mechanical properties as those obtained with conventional phenol/
formaldehyde or urealformaldehyde resins may be obtained using the binder of the present invention in 30 concentrations from 25 to 70% less than that of the conventional binder. These optimum material properties are obtained, for example, when the binder used is a Mo-2431 ..~, !~ , 33~
polymethylenepolyphenylpolyisocyanate having the viscosity and distribution of isomers required in the present invention.
It is immaterial whether the polyisocyanate mixture was obtained from crude diphenylmethane diisocyanate by distilling off the 2,4' and/or
simple to ~ake and use, 'nas reduced reactivit,y with water and is economical.
These a~d other objects which will ~e appar2n~
to those skilled ln t'ne art are accomplished by a,~
aqueous emulsion made from a~ 5-70 parts by weight emulsifier-free pol~,7isocyanate which polyisocyanate has not been modified to render it hydrophills and emulsifiable and b) 30-95 parts by ~Jeig'nt aqueous paraffin dispersion having a paraffin content of from 3 to 65 wt. % in a quantity of water such that the emulsion has a solids content of from 6 to 90 wt. ~.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to aqueous emulsions of organic polyisocyanates, aqueous paraffin dispersions and optionally additional water. These emulsions are made by emulsifyiny a) from 5 to 70 parts by weight ~preferably from 10 to 60 parts by weight) of an emulsifier-free polyisocyanate which has not been modified to render it hydrophilic and emulsifiable and b) from 30 to 95 parts by weight ~preferably from 40 to 30 parts by welgh-t), of an aqueous paraffin dispersion containing from 3 to 65 wt.
% of paraffin, and optionally the usual additives in the usual quantities in water without the addition of emulsifier. The quantity of water employed is calculated to provide an emulsion having a solids content (composed of a) plus b)) of from 6 to 90 wt. %, preferably from 10 to 70 wt. %.
The present invention also relates to the use of these polyisocyanate emulsions as binders in the production of molded articles by 'not molding a mass of size reduced organic and/or inorganic raw materials.
~o-2431 33~
mhe emulsions of the present invention may be prepared, for example, by mixing the polyisocyanate with the paraffin disp2rsion, optionally further diluted with water.
Examples of suitable paraffin dispersions include the dispersions obtalned according to German Offenlegungsschrift 2,948,015 by the dispersion of paraffins in the presence of dispersing agents based on cationic polyelectrolytes. The dispersions disclosed in ~.S. Patents 2,655,496 and 3,965,032 or similar products of ~lobil Oil (such as Mobilcer-A-331 or Mobil Oil experimental product ED 80/196 (see G. W. Ball et al, Holz-Zentralblatt ~o. 88 of 23rd July, 1979; or ~.I. Sachs, Holz-~entralblatt 103, No. 20, pages 295-296, and No. 25, pages 384-388 (1977)) may also be used.
The aqueou.s emulsions may be produced in industrial plants by mixing the starting components in special mixing apparatus, such as static mixers;
stirrers with mixing heads; Inline-Ultra-Turrax apparatus (as ~abricated by Ja~ke und Kunkel, ~-7~12, Bad Krotzingen-2,)by high pressure mixIllg heads or high pressure inJection inoculation blocks.
The emulsions of the present invention may be prepared and processed either batchwise or continuously. Continuous processes are preferred due to their increased reliability in production.
The isocyanate components used in the preparation of the emulsions of the present invention may `~e aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates such as those described, for example, by W. Siefken in Justus Liehigs Annalen der Chemie, 562, pages 75 to 136. Suita~le isocyanates include those corresponding to the formula ~o-2431 3~
Q (NC~)n in which n ~epres~nts 2 to 4, preferably 2, and ~2 repr~sents an alip~atic hydroc~rbon group havlng 2 to 18 (preferably 6 to 10) carbon atoms, a cyclo-aliph~tic hydrocar~on group having 4 to 23 (preferably 5 to 13) carbon atoms, ~n aromatic hydrocarbon group havin~ 6 to 23 (preferably 6 to 13) carbon atomst or an araliphatic hydrocarbon group havin~ 8 to 15 (preferably 8 to 13~ carbon ato~s.
Specific examples of such isocyanates are: 1,4-tetra-methylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1,3-diiso-cyanate, cyclohexane-1,3- and -1,4-diisocyanate and mixtures of these isomers; l-isocyanato-3,3,S-tri-methyl-5-isocyanatomethyl-cyclohexane (DE-3 1,202~785, U.S. Patent 3,401,190), 2,4- and 2,6-hexanydro-tolylene diisocyanate and mixtures of these isomers;
hexahydro-1,3-- and/or 1,4-phenylene diisocyanate, perhydro-2,4'-- and/or 4,4'-dipIlenylmethane diisocyanat~, 1,3- and 1,4~phenylene diisocyanate, 2,4-and 2,6-tolylene diisocyanate and mixtures OL these isomers; diphenylmethane-2,4' and/or 4,4'-diisocyanate, and naphthylene-1,5-diisocyanate.
The following may also be used in the present invention: triphenylmethane.-4,4',4"-trilsocyanate;
polyphenyl-polymethylene-polyisocyanates which may be obtained by aniline-formaldehyde condensation followed by phosgenation (described, for example in ~ritish Patents 874,430 and 848,671); m- and p-isocyanatophenyl sulfonyl isocyanates (U.S. Patent 3,454,606);
Mo-2431 perchlorinated arylpolyisocyanates (described for example~ in German Auslegeschrift 1,157,601 (U.S.
Patent 3,277,138)); polyisocyanates containing carbo-diimide groups (described i.n German Patent 1,092,007 (U.S. Patent 3,152,162) and in German Offenlegungs-schriften 2,504,400, 2,537,685 and 2,552,350);
norbornane diisocyanates (U.S. Patent 3,~92,330); poly-isocyanates containing allophanate groups ~described in Bri~ish Patent 994,890, Belgian Patent 761,626 and Netherlands Patent Specification 7,102,524); polyiso-cyanates containing isocyanurate groups (described in U.S. Patent 3,001,973, German Patents 1,022,789;
1,222,067 and 1,027,394 and in German Offenlegungs-schriften 1,929,034 and 2,004,048); polyisocyanates con~aining urethane groups (described ln Belgian Patent 752,261 or in U.S. Patents 3 9 394,164 and 3,644,457);
polyisocyanates containing acylated urea groups (German Patent 1,230,778); polyisocyanates containing biuret groups (described in U.S. Patents 3,124,605; 3,201,372 and in British Patent 889,040); polyisocyanates prepared by telomerization reactions (U.S. Patent 3,654,106); polyisocyanates containing ester groups (British Patents 965,474 and 1,077,956, U.S. Patent 3~567,763 and German Patent 1,231,688); reaction products of the above-mentioned isocyanates with acetals (German Patent 1,072,385) and polyisocyanates containing polymeric fatty acid esters (U.S. Patent 3,455,883). Any mixture of the above-mentioned poly-isocyanates may also be used.
It is generally preferred to use the commercially readily availa.ble polyisocyanates, such as 2,4 and 2,6-tolylene diisocyanate and any mixtures of these isomers ("TDI"); polyphenyl polymethylene poly-Mo-2431 .~
~ 3 ~ ~
isocyanates as prepared by aniline-formaldehyde condensation followed by phosgenation ("crude MDI");
and polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups, biuret groups or other groups used in isocyanate chemistry ("modified polyisocyanates").
Those modified polyisocyanates which are derived from 2,4 and/or 2,6-tolylene diisocyanate or from 4,4'-and/or 2,4'- and/or 2,2'-diphenylmethane diisocyanate are particularly pre:Eerred.
Prepolymers with an average molecular weight of about 300 to 2000 containing isocyanate end groups, such as those obtained in known manner by reacting relatively high molecular weight and/or low molecular weight polyols with an excess of polyisocyanate, may also be used in preparing the emulsion o-f the present invention. Relatively high molecular weight polyols which are particularly suitable for making such prepolymers are compounds having from 2 to 8 hydroxyl groups, especially those with molecular weights from 400 to 10,000 (preferably from 800 to 5000). Such polyols include polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyester amides having at least two, generally two to eight, preferably two to four hydroxyl groups, which are known to be useful in the production of both homogeneous and cellular polyurethanes~
Suitable polyesters containing hydroxyl groups include the reaction products of polyhydric (preferably 30 dihydric) alcohols, optionally with the addition of trihydric alcohols, and polybasic (preferably dibasic) carboxylic acids. Instead o free polycarboxylic Mo-2431 ~r 3~
acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof may also be used in the preparation of the polyesters. The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and/or heterocyclic and they may be substituted (e.g. with halogen atoms), and/or unsaturated.
The following are specific examples of carboxylic acids and deri~atives which may be used to prepare the polyesters: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic acid anhydride, tetrahydrophthalic acid anhydride, hexa-hydrophthalic acid anhydride, tetrachlorophthalic acid anhydride, endomethylene tetrahydrophthalic acid anhydride, glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric acid, dimerized and trimerized unsaturated fatty acids optionally mixed with monomeric unsaturated fatty acids (such as oleic acid); dimethy:Lterephthalate and terephthalic acid-bis-glycol esters. Examples of suitable polyhydric alcohols include: ethylene glycol, (1,2)- and (1,3)-propylene glycol, (1,4)- and (2,3)-butylene glycol, (1,6)-hexanediol, (1,8) octanediol, neopentyl glycol, 1,4-bis-hydroxymethylcyclohexane, 2 methyl-1,3-propanediol, glycerol, trimethylolpropane, (1,2,6)-hexanetriol, (1,2,4)-butanetriol, trimethylolethane, pentaerythritol, quinitol, mannitol and sorbitol, formitol, methyl glycoside, di-, tri-, tetra- and 3~ higher polyethylene glycols, di-, tri-, tetra- and higher polypropylene glycols and di-, tri- and tetra-Mo-2431 ~r.r and higher polybutylene glycols. The polyesters may contain a proportion of carboxyl end groups.
Polyes~ers of lactones, e.g. of ~ -caprolactone, or of hydroxycarboxylic acids, e.g., of ~ -hydroxycaproic acid 7 may also be used.
The polyethers which may be used in the present in~ention contain at least two, generally two to eight, preferably two to three hydroxyl groups.
These polyethers may be prepared by the polymerization of epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin, either on their own in the presence of Lewis catalysts such as BF3, or by chemical addition of these epo~ides (preferably ethylene oxide and propylene oxide, optionally as mixtures or lS successively) to starting components which have reactive hydrogen atoms. Appropriate starting components are water, alcohols, ammonia or amines.
Specific e~amples of such starting components are ethylene glycol, (1 5 3)- or (1,2)-propylene glycol, trimethylolpropane, glycerol, sorbitol, 4,4'-dihydroxy-diphenylpropane, aniline, ethanolamine or ethylene diamine. Sucrose polyethers such as those described in German Auslegeschriften 1,176,358 and 1,064,938 and polyethers started on formi~ol or formose (German Offenlegungsschriften 2,639,083 and 2,737,951) may also be used. It is in many cases preferred to use polyethers containing predominantly primary O~ groups (up to 90% weight % thereof, based on all. the O~l groups present in the polyether). Polybutadienes containing OH groups are also suitable to the present invention.
Mo-2431 '~;.
33~
Suitable polythioethers include the condensation products of thiodiglycol obtained by reacting the ~hiodiglycol on its own and/or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amino alcohols. The products thus obtained may be, for example, mlxed polythio ethers, polythio ether esters, or polythio ethPr ester amides, depending upon the co-components.
Suitable polyacetals include those prepared from glycols such as diethylene glycol, triethylene glycol, 4,4'-dioxethoxydiphenyldimethylmethane, he~ane-diol and formaldehyde. Polyacetals suitable for purposes of the present invention may also be prepared by the polymerization of cyclic acetals such as trioxane (German Offenlegungsschrift 1,694,128).
The polycarbonates with hydroxyl groups which may be used in the present invention are known to those in the art. Such polycarbonates may be prepared, for example, by the reaction of diols such as (173)-propane diol, (1,4)-butanediol and/or (1,6)-hexanediol, di-, tri- or tetra-ethylene glycol or thiodiglycol with diarylcarbonates (e.g. diphenylcarbonate) or phosgene (German Auslegeschriften 1,694,080; 1,915,908 and 2,221,751 and German Offenlegungsschrift 2,605,024).
Polyester amides and polyamides which may be used in the practice of the present invention include e.g. the predominantly linear condensates ob~ained from polyvalent saturated or unsaturated carboxylic acids or their anhydrides and polyvalent saturated or unsaturated amino alcohols, diamines, polyamines or mixtures thereof.
Mo-2431 .. , ,. ~.
3~
Polyhydroxyl compounds which already con-tain urethane or urea groups and modlfied or unmodified natural polyols such as castor oil or carbohydrates (e.g. starch) may also be used in the present invention. Addition products of alkylene oxides with phenol formaldehyde resins or with urea formaldehyde resins are also suitable to the present invention.
Suitab]e low molecular weight polyols (molecular weight from 62 to 399) include, for example, the compounds mentioned above as starting components for the preparation of relatively high molecular weight polyols.
Catalysts may also be used in practicing the present invention. Suitable catalysts include those of known type such as tertiary amines. Specific examples of appropria~e catalysts are: trie~hylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, -cocomorpholine, N,N,N',N' tetramethyl-ethylene-diamine, 17 4-diaza-bicyclo-(2,2,2)-octane, N-methyl-N'~dimethyl-aminoethylpiperazine, N,N-dimethylbenzyl-amine, bis-(N,N diethylaminoethyl)-adipate, N,N-di-ethylbenzylamine, pentamethyl-diethylene-triamine, N,N-dimethylcyclohexylamine, N,N,NI,N'-tetramethyl-1,3-butane diamine, N,N-dimethyl- ~-phenylethylamine, 1,2-dimethylimidazole and 2-methylimidazole. The catalysts used may also be known Mannich bases oE
secondary amines such as dimethylamine and aldehydes tpreferably formaldehyde~ or ketones (such as acetone, methyl ethyl ketone or cyclohexanone), and phenols (such as phenol, nonylphenyl or bisphenol). Examples of other tertiary amines with isocyanate reactive hydrogen atoms used as catalyst include Mo-2431 33'~
triethanolamine, triisopropanolaminQ, N-methyldiethanolamine, N-ethyl-diethanolamine, N,N-dimethylethanolamine and their reaction products with alkylene oxides such as propylene oxide and/or ethylene oxide.
Silaamines having carbon-silicon bonds as described e~g. in German Patent 1,229,290 (corresponding to U.S. Patent 3,620,984) may also be used as catalys~. Specific examples of such compounds are 2,2,4-trimethyl-2-silamorpholine and 1,3-di-ethylaminomethyl-tetramethyl-disiloxane.
The catalysts used may also be bases containing ni~rogen (such as tetraalkylammonium hydroxides) or alkali metal hydroxides (such as sodium hydroxide), alkali metal phenolates (such as sodium phenolate) or alkali metal alcoholates (such as sodium methylate). Hexahydrotriazines may also be used as catalysts. Organic metal compounds, particularly organîc tin compounds may also be used as catalysts.
The preferred organic tin compounds are tin-(II) salts of carboxylic acids such as tin-(II) acetate, tin (II) octoate, tin-(II)-ethyl hexoate and tin-(II)-laurate and tin-(IV) compounds such as dibutyl tin oxide, dibutyl tin dichloride, dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin maleate and dioctyl tin diacetate. Mixtures of any of the above-mentioned catalysts may, of course, also be used.
Additional representatives of catalysts which may be used in the present invention and the mode of action of the catalysts are described in Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, e.g. on pages 96 to 102.
Mo-2431 '~
The emulsions of ~he present invention are preferably used as binders for materials containing lignocellulose. Emulsions which have proved particularly suitable for this purpose are those in which the polyisocyanate component is the phosgenation product of the undistilled ground fraction which may be obtained by the removal of 25 to 90 wt. % (preferably 30 to 98 wt. %) of 2,2', 2,4' andlor 4,4'-diamino-diphenylmethane from an aniline/formaldehyde condensate. Another particularly desirable polyisocyanate component is the undistilled ground fraction obtained by removal of from 25 to 90 wt. %
(preferably from 30 to 85 wt. %) of 2,2'-, 2,4'-and/or 4,4'-diisocyanatodiphenylmethane from the crude phosgenation product of an aniline/formaldehyde condensate. In either of these polyisocyanates, the isocyanate component should generally contain from 35 to 70 wt. % (preferably from 45 to 60 wt. %) o~
diisocyanatodiphenylmethane, the 2,4'-diisocyanato-diphenylmethane content should amount to from l to 8 wt. % (preferably from 2 to 5 wt. %) while the 212'-di-isocyanatodiphenylmethane content should preferably be from 0 to 2 wtn %. The isocyanate component should generally have a viscosity at 25C of from 50 to 600 mPas, (preferably from 200 to 500 mPas) and an isocyanate content of from 28 to 32 wt. % (see German Auslegeschrift 2 J 711,958).
Such ground fractions may be obtained, for example, when from 45 to 90 wt. % ~preferably from 55 to 85 wt. %) of 4,4'-diisocyanatodiphenylmethane is removed from a crude diphenylmethane diisocyanate containing more than 85 wt. % (preferably more than 90 Mo-2431 , t, :~
3~3~
ll~
wt. ~) of 4,4'-diisocyanatodiphenylmethane. A crude diphenylmethane diisocyanate of this kind may be obtained, for example, by the process according to German Of-fenlegungsschrift 2,356,828.
Another possible method for making suitable ground fractions is by distilling off 25 to 80 wt. %
(preferably 30 to 60 wt. %) of 2,4-diisocyanato-diphenylmethane and optionally 4,4'- or 2,2'-diiso-cyanatodiphenylmethane from a crude phosgenation product containing from 60 to 90 w~. % (preferably from 65 to 75 wt. %) of diisocyanatodiphenylmethane isomers and having from 20 to 60 wt. % (preferably from 30 to 40 wt. %) of 2,4'-isomers. Distillation may be carried out in a manner such that the residue has the composition indicated above.
I~ is of course possible (and in many cases simpler in practice) to obtain the desired composition of isomers and oligomers in the polyisocyanate mixture by blending various ground fractions.
In addition to the preferred unmodified poly-isocyanates, polyisocyanates modified to be self-releasing from the mold may also be mixed with the paraffin dispersions. Such polyisocyanates which have been modified to be self-releasing from the mold have been described, for example, in German Offenlegung-sschrift 3,109,317 (U.S. Patent 4,258,169), German Offenlegungsschrift 2,932,175 ~U.S. Patent 4,257,995) and U.S. Patent 4,257,996. These disclosed poly-isocyanates are modified with phosphorus compounds.
The modification of polyisocyanates with from 0.1 to 30 30 wt. % of phosphoric acid-Cl-C7-dialkylesters (preferably phosphoric acid-di-n-butylester) is Mo-2431 '~
known. In accordance with the present invention, these modified polyisocyanates are mixed with the paraffin dis-persion without the addition of emulsifier Suitable lignocellulose-containing raw materials which may be bound with the emulsions of the present inven-tion include wood, tree bark, cork, bagasse, straw, flax, bamboo, alfalfa grass, rice husks, sisal fibers and coconut fibers. These raw materials may be in the form of ~ranules, chips, fibers or powders and may have a water content of from 0 to 35 wt. % (preferably -from 5 to 25 wt. %). In accordance with the present invention, the binder is added to the lignocellulose-containing raw material in a quantity of from 1 to 100 wt. ~ (preferably from 2 to 12 wt. %3 and molded generally ~ith the appl i-- 15 cation of heat and pressure to ~orm boards or shaped products.
Molded products may, of course, also be pro-duced in accordance with the present invention from other organic (e.g. plastic waste of all kinds) and/or inorganic raw materials (e.g. expanded mica or silicate pellets).
When the emulsion of the present invention is used, the material which is to be molded is mixed with the binder, preferabIy by spraying it with the a~ueous emulsion in order to obtain very homogeneous distribu-tion. It has been found that the aqueous emulsions of the present invention have a sufficiently low viscosity to enable them to be sprayed even when they have an isocyanate content of up to 70%. The solwtions of urea/
formaldehyde and phenol/Eormaldehyde resins conventionally used in the manufacture o e molded Mo-243I
.i~
~'~..,i`P"
board and similar ma~erials can, however, generally be sprayed only i~ the solid content is below ~0%. The present invention thus provides a method in which less water is used than w~s previously possible so that less water need be removed during the stage of hot molding and/or subsequent conditioning. Further, the ligno-cellulose materials need not be dried as extensively before being mixed with the binder as is required in known processes.
Since the polyisocyanates employed in the present invention have not been modified to render them hydrophilic and they contain no added emulsifiers, the wood chip board obtained thererom has the lowest possible absorption of water so that the tendency to swell upon contact with water is significantly reduced.
Periods of delay may occur between the individual stages of the process (preparation o~ the emulsion, spraying oE the material to be used). Delays may a~so occur due to mechanical difficulties or the need to readjust the operating conditions. However, the reaction between the isocyanate and wa~er in the emulsions of the present invention proceed at a rate sufficiently slow to permit delays of 2 hours or more between preparation of the emulsion and hot molding without significantly affecting the product. The velocity of the reaction may be reduced by altering the reactivity of the polyisocyanates with water. The reaction velocity may, for example, be considerably reduced by increasing -the proportion of 2,l~'- and/or 2,2'-diphenylmethane diisocyanate.
Mo-2431 . .~ , .
3;~
~17-Multilayered boards or articles composed of veneers, pap~r or fabric may be produced in a manner analogous to that for the production of molded ~oard.
Mul-tilayered boards or shaped articles composed o~
veneers and middle layers of strips and bars or small rods, (so-called joiner boards) may be produced in accordance with the present invention by treating the veneers with the polylsocyana~e emulsions as described above and then pressing these veneers to the middle layers, generally at elevated temperatures and pressures. Temperatures of from 100 to 250~C are general]y advantageous in such treatments with temperatures from 130 to 220C being particularly useful. The initial molding pressure employed should preferably be from 5 to 150 bar with the pressure in most cases falling towards zero during the course of the molding process.
In accordance with the present invention, the polyisocyanate emulsions may also be used in combination with the polyhydroxyl compounds described above in an NCO/OH ratio ranging from 1-2 to 10:1, preferably from 1.5:1 to 1:1. The two components may be used either separately or as a reac~ive mixture.
Such combinations of polyisocyanates and polyhydroxyl compounds are of practical importance as binders, e.g.
for binding granulated cork. ~nown blowing agents may also be used in a quantity of ca. 0.5 to 30 wt. ~, based on the binder or impregnating agent. In addition or alternatively, additives which influence foaming or the chemical reaction between polyisocyanates, ligno-cellulose-containing material and, if used, polyhydroxyl compounds may also be employed. Examples Mo-2431 .~,...
'~
3 ~ 3~
of such additives are stabilizers, catalysts and activators. Such acldltives, if used, should generally be used in a quantity of from 0.05 to 10 wt. % based on the binder or impregnating agent.
The polyisocyanate emulsions to be used as binders in the practice of the present invention may also be combined with aqueous solutions of the condensation products of formaldehyde with urea and/or melamine and/or phenol, which have been used predominantly in the woodworking industry. The emulsions may also be combined with other less commonly used binders and impregnating agents, such as sulphite waste liquors (lignin sulphonate or other industrial llgnin solutions obtained from the processing of wood) or tanning substances (such as tannin), in a quantity such that the proportion of the binder of the present invention to the additional binders is in the range of from 1:10 to 10: 1 3 preferably from 1-5 to 5:1. The polyisocyanate emulsion and the additional binder may be used separately or as mixtures.
Such emulsion-binder combinations are particularly advantageous for the manufacture of multi-layered boards which have special properties. For example, the outer lay~rs may be treated with conventional adhesives (alone or together with the polyisocyanate emulsion of the present invention) while one or more inner layers are treated with the polyisocyanate emulsions of the present invention (alone or together with conventional adhesives) and the layers may subsequently be pressed together.
The boards or molded articles based on ligno-Mo-2431 ~,, O.~ .~, 3~
cellulose-containing other organlc and/or inorganic raw materials produced in accordance with the present invention are particularly suitable for use in the building industry because of their excellent mechanical properties. In order to impart to -these boards or molded articles the necessary resistance to mold, insects, or fire, the usual commercial additives (such as organic or inorganic protective agents) may be added to the binders or raw materials, either neat or as solutiolls. These additives are generally used in a quantity of about 0.05 to 30 wt. %, preferably 0.5 to 20 wt. %, base~ on the entire quantity of material.
Solvents which may be used in the present invention include water and organic solvents such as residual oils from the petroleum industry, chlorinated hydrocarbons, etc. These solvents generally do not impair adhesive quality. In contrast to boards glued with phenol/formaldehyde resin, the materials produced in accordance with the present invention have the advantage that neither efflorescence of salt nor "bleeding" occurs.
Due to the powerful adhesive force of the binders of the present invention, molded products impregnated or bonded with these binders have a tendency to adhere to the surfaces of the hot presses or molds. This problem may be avoi~ed by the addition of mold release agents to the isocyanate emulsions.
Another solution ~o the adhesive problem is application of the mold release agents either neat or as solutions to the metallic surfaces which come into contact with the moldings or to the surface of the molding. The mold release agen~s used may be any of the substances Mo-2431 known to be sui~able for this purpose although it is preferred to use the compounds according ~o German Offenlegungsschrift 2,325~926 which catalyze the formation of isocyanurates from isocyanates. Examples of such mold release agents include phenol Mannich bases, derivatives of hexahydrotriazine and alkali metal salts of carboxylic acids. Another method of preventing adherence to the surface of the molds is provision of a separating layer between the molding and the metallic surfaces of the mold. This separating layer may consist of webs, foils or size reduced material made of various substances (e.g. plastics, paper, wood or metal).
As mentioned above, the isocyanate emulsions of the present invention may provide substantial improvements in the manufacture of chipboard as compared to conventional binders based on phenol/formaldehyde or urea/formaldehyde resins, both in the mechanical properties of the product and with resp~ct to processing considerations. Thus, in the case of wood chipboard, when the binder of the present invention is used in the same quantity as the phenol/formaldehyde or urea/formaldehyde resins conventionally used may provide an increase in flexural strength by up to 50% (in addition to an improvement in other mechanical properties). The same mechanical properties as those obtained with conventional phenol/
formaldehyde or urealformaldehyde resins may be obtained using the binder of the present invention in 30 concentrations from 25 to 70% less than that of the conventional binder. These optimum material properties are obtained, for example, when the binder used is a Mo-2431 ..~, !~ , 33~
polymethylenepolyphenylpolyisocyanate having the viscosity and distribution of isomers required in the present invention.
It is immaterial whether the polyisocyanate mixture was obtained from crude diphenylmethane diisocyanate by distilling off the 2,4' and/or
4,4'-diisocyanatodiphenylmethane or by the removal of pure diaminodiphenylmethane from crude diaminodiphenyl-methane, followed by phosgenation of the resulting undistilled ground fraction of polyarylamines.
If the polyisocyanate contains more than 75 wt. % of diisocyanatodiphenylmethane, the physical properti.es of the chipboard produced therefrom generally deteriorate. If, on the other hand, the diisocyanatodiphenylmethane content falls below 35 wt.
%, the binder generally becomes too highly viscous at room temperature and will be difficult to emulsify.
The following Examples illustrate the present invention. Numerical data are to be understood as parts by weight or percentages by weight unless otherwise indicated.
EXAMPLES
Example 1 An 8% paraffin dispersion was prepared from 22 parts of a 65% aqueous paraffin dispersion (Trade product Mobilcer 739 (Mobil Oil-AG)) and 158 parts of water, by stirring the ingredients together. 55 parts of polyisocyanate A of German Offenlegungsschrift 2,711,958 were emulsified in this mixture within 30 seconds by means of a high speed stirrer.
2900 Parts of industrially producecl coniferous wood chips having a moisture content of 5~ were then Mo-2431 '`~., ~.~8~
sprayed with the emulsion in a laboratory sizing machine, using two-material eddy stream nozzles. A
molding was produced from these chips on a steel plate which had previously been trea~ed with an aqueous potassium acetate/diethylene glycol solution. The surface of the molding had also been wetted with a solution of mold release agent. After a molding time of 3.2 minutes at a hotplate temperature of 170 DC and at a molding pressure of 25 bar (which was reduced to 5 bar after 1/3 of the molding time), a chipboard having a ~ransverse tensile strength of 0.76 mPa. was obtained.
Example 2 An emulsion was prepared from 63 parts of a 35% aqueous paraffin dispersion (Trade product Mobilcer Ed 80/229) and 126 parts of polyisocyanate B
of German Offenlegungsschrift 2,711,958 by the inoculation block technique.
189 Parts of the emulsion were then added to 2250 parts of middle layer chips consisting of a mixture of conlferous wood and hardwood and having a moisture content of 7%. 980 Parts of coniferous wood top layer chips having a moisture content o 9% were then wetted with 240 parts of a commercial weakly alkaline 45% phenol/formaldehyde resin.
(Bakelite-2501; sold by Bakelith GmbH, D-5860, Iserlohn-7).
Three layered moldings were formed and a middle layer bonded with phenol/formaldehyde resin and a middle layer bonded with isocyanate emulsion, and the layers were pressed at a hotplate temperature of 170C.
The resulting chipboards of standard type V
100 according to DIN 68 763 had a V 100 transverse tensile strength of 0.24 mPa and a thickness swelling after 24 hours storage in water o~ 10.5%.
Mo-2431 3'133~
Example 3 An emulsion was prepared from 143 parts of water, 17 parts of potassium bifluoride ( Basilit SP
of Desowag-Bayer-Holzschutz GmbH), 29 parts of a 50%
paraffin dispersion ( Mobilcer 161 of Mobil Oll-AG) and 143 parts of polyisocyanate C of Çerman Offen-legungsschrift 2,711,958 by means of a high pressure mixing head. This emulsion was used to wet 2950 parts of an industrially produced wood chip mixture of 50%
coniferous wood and 50% hard wood having a moisture conten~ of 5%. These chips were placed between two pinewood veneers 1.5 mm thick as top layers to produce a molding which was then hardened as described in Example 1. The decorative, mold resistant chipboard obtained had high flexural strength in the direction of the fibers of the veneers, a V 20 transverse ~ensile streng~h of 1.08 mPa and a V 100 transverse t~nsile strength of 0.24 mPa.
2~
~o-2431 ~f , Ji~
If the polyisocyanate contains more than 75 wt. % of diisocyanatodiphenylmethane, the physical properti.es of the chipboard produced therefrom generally deteriorate. If, on the other hand, the diisocyanatodiphenylmethane content falls below 35 wt.
%, the binder generally becomes too highly viscous at room temperature and will be difficult to emulsify.
The following Examples illustrate the present invention. Numerical data are to be understood as parts by weight or percentages by weight unless otherwise indicated.
EXAMPLES
Example 1 An 8% paraffin dispersion was prepared from 22 parts of a 65% aqueous paraffin dispersion (Trade product Mobilcer 739 (Mobil Oil-AG)) and 158 parts of water, by stirring the ingredients together. 55 parts of polyisocyanate A of German Offenlegungsschrift 2,711,958 were emulsified in this mixture within 30 seconds by means of a high speed stirrer.
2900 Parts of industrially producecl coniferous wood chips having a moisture content of 5~ were then Mo-2431 '`~., ~.~8~
sprayed with the emulsion in a laboratory sizing machine, using two-material eddy stream nozzles. A
molding was produced from these chips on a steel plate which had previously been trea~ed with an aqueous potassium acetate/diethylene glycol solution. The surface of the molding had also been wetted with a solution of mold release agent. After a molding time of 3.2 minutes at a hotplate temperature of 170 DC and at a molding pressure of 25 bar (which was reduced to 5 bar after 1/3 of the molding time), a chipboard having a ~ransverse tensile strength of 0.76 mPa. was obtained.
Example 2 An emulsion was prepared from 63 parts of a 35% aqueous paraffin dispersion (Trade product Mobilcer Ed 80/229) and 126 parts of polyisocyanate B
of German Offenlegungsschrift 2,711,958 by the inoculation block technique.
189 Parts of the emulsion were then added to 2250 parts of middle layer chips consisting of a mixture of conlferous wood and hardwood and having a moisture content of 7%. 980 Parts of coniferous wood top layer chips having a moisture content o 9% were then wetted with 240 parts of a commercial weakly alkaline 45% phenol/formaldehyde resin.
(Bakelite-2501; sold by Bakelith GmbH, D-5860, Iserlohn-7).
Three layered moldings were formed and a middle layer bonded with phenol/formaldehyde resin and a middle layer bonded with isocyanate emulsion, and the layers were pressed at a hotplate temperature of 170C.
The resulting chipboards of standard type V
100 according to DIN 68 763 had a V 100 transverse tensile strength of 0.24 mPa and a thickness swelling after 24 hours storage in water o~ 10.5%.
Mo-2431 3'133~
Example 3 An emulsion was prepared from 143 parts of water, 17 parts of potassium bifluoride ( Basilit SP
of Desowag-Bayer-Holzschutz GmbH), 29 parts of a 50%
paraffin dispersion ( Mobilcer 161 of Mobil Oll-AG) and 143 parts of polyisocyanate C of Çerman Offen-legungsschrift 2,711,958 by means of a high pressure mixing head. This emulsion was used to wet 2950 parts of an industrially produced wood chip mixture of 50%
coniferous wood and 50% hard wood having a moisture conten~ of 5%. These chips were placed between two pinewood veneers 1.5 mm thick as top layers to produce a molding which was then hardened as described in Example 1. The decorative, mold resistant chipboard obtained had high flexural strength in the direction of the fibers of the veneers, a V 20 transverse ~ensile streng~h of 1.08 mPa and a V 100 transverse t~nsile strength of 0.24 mPa.
2~
~o-2431 ~f , Ji~
Claims (18)
1. An aqueous emulsion comprising:
a) 5-70 parts by weight emulsifier-free polyisocyanate which polyisocyanate has not been modified to render it hydrophilic and emulsifiable and b) 30-95 parts by weight aqueous paraffin dispersion said dispersion having a paraffin content from 3 to 65 wt. %
in a quantity of water such that the emulsion has a solids content of from 6 to 90 wt. %.
a) 5-70 parts by weight emulsifier-free polyisocyanate which polyisocyanate has not been modified to render it hydrophilic and emulsifiable and b) 30-95 parts by weight aqueous paraffin dispersion said dispersion having a paraffin content from 3 to 65 wt. %
in a quantity of water such that the emulsion has a solids content of from 6 to 90 wt. %.
2. The emulsion of Claim 1 further comprising a stabilizer and/or catalyst and/or activator.
3. The emulsion of Claim 1 wherein the poly-isocyanate a) is (i) the phosgenation product of an undistilled ground fraction of 25-90 wt. % of 2,2'-2,4'- and/or 4,4'-diaminodiphenylmethane produced from an aniline/formaldehyde condensate or (ii) an undistilled ground fraction of 25-90 wt. % of 2,2'-2,4'- and/or 4,4'-diisocyanatodiphenylmethane made from a crude phosgenation product of an aniline/formaldehyde condensate said polyisocyanate a) containing from 35-70 wt. % diisocyanatodiphenylmethane having a viscosity at 25°C of from 50 to 600 mPas and an isocyanate content of from 28-32 wt. %.
4. The emulsion of Claim 3 wherein the diisocyanatodiphenylmethanes include from 1 to 8 wt. %
of 2,4'-diisocyanatodiphenylmethane and from 0 to 2 wt. % of 2,2'-diisocyanatodiphenylmethane.
of 2,4'-diisocyanatodiphenylmethane and from 0 to 2 wt. % of 2,2'-diisocyanatodiphenylmethane.
5. The emulsion of Claim 1 wherein the polyisocyanate a) is obtained as a ground fraction by removing 45-90 wt. % of 4,4'-diphenylmethane diiso-cyanate by distillation from a crude diphenylmethane diisocyanate containing more than 85 wt. % diphenyl-methane diisocyanate.
6. The emulsion of Claim 1 wherein the poly-isocyanate a) is obtained by phosgenation of an undistilled ground fraction remaining after 45-90 wt. %
of 4,4'-diaminodiphenylmethane has been distilled off from crude diaminodiphenylmethane containing more than 85 wt. % pure diaminodiphenylmethane.
of 4,4'-diaminodiphenylmethane has been distilled off from crude diaminodiphenylmethane containing more than 85 wt. % pure diaminodiphenylmethane.
7. The emulsion of Claim 1 wherein the poly-isocyanate a) is that obtained by distilling off 25-80 wt. % 2,4'- and/or 4,4'-diisocyantodiphenylmethane from a crude diphenylmethane diisocyanate containing from 60 to 90 wt. % diisocyanatodiphenylmethane isomers in which 20 to 60 wt. % is 2,4'-isomers.
8. The emulsion of Claim 1 wherein the poly-isocyanate a) has been prepared by phosgenation of an undistilled ground fraction obtained by removal by distillation of 25-80 wt. % 2,4'-diaminodiphenylmethane and optionally 4,4'-diaminodiphenylmethane from a crude diaminodiphenylmethane containing 60-90 wt. % pure diaminodiphenylmethane which pure diaminodiphenyl-methane contains 20-60 wt. % 2,4'-diaminodiphenyl-methane.
9. A process for the production of molded articles by hot molding a mass of size reduced organic and/or inorganic raw materials in which the aqueous emulsion of Claim 1 is used as a binder.
10. The process of Claim 9 wherein the emulsion used as the binder is used in a quantity of from 1 to 100 wt. % (based on raw material).
11. The process of Claim 9 wherein the emulsion used as binder is used in combination with a polyol in quantities such that the NCO/OH ratio is in the range of from 1:2 to 10:1.
12. The process of Claim 11 wherein a blowing agent and/or foaming agent is employed.
13. The process of Claim 11 wherein from 0.01 to 10 wt. % catalyst is employed.
14. The process of Claim 9 wherein from 0.01 to 10 wt. % catalyst is employed.
15. The process of Claim 9 wherein the emulsion is used in combination with phenol/formal-dehyde resin and/or urea/formaldehyde resin and/or melamine/formaldehyde resin.
16. The process of Claim 9 wherein the molded article is a multi-layered board in which the outer layers are bonded with a urea/formaldehyde resin and/or a melamine/formaldehyde resin and/or a phenol/formal-dehyde resin and the middle layers are bonded with the aqueous emulsion.
17. The process of Claim 16 wherein the outer layers are bonded with a urea/formaldehyde resin and/or melamine/formaldehyde resin and/or a phenol/formal-dehyde resin in combination with the aqueous emulsion.
18. The process of Claim 17 wherein the middle layers are bonded with the aqueous emulsion in combination with urea/formaldehyde resin and/or a melamine/formaldehyde resin and/or a phenol/formal-dehyde resin.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19823201111 DE3201111A1 (en) | 1982-01-15 | 1982-01-15 | NEW AQUEOUS POLYSOCYANATE EMULSIONS AND THEIR USE AS BINDERS FOR THE PRODUCTION OF MOLDED BODIES |
| DEP3201111.3 | 1982-01-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1184334A true CA1184334A (en) | 1985-03-19 |
Family
ID=6153166
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000418781A Expired CA1184334A (en) | 1982-01-15 | 1982-12-30 | Aqueous polyisocyanate emulsions useful as binders in the production of molded articles |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4472230A (en) |
| EP (1) | EP0084313B1 (en) |
| AT (1) | ATE16098T1 (en) |
| CA (1) | CA1184334A (en) |
| DE (2) | DE3201111A1 (en) |
| DK (1) | DK172719B1 (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE34093E (en) * | 1982-05-24 | 1992-10-06 | Aqueous adhesive compositions | |
| US4710580A (en) * | 1986-08-12 | 1987-12-01 | American Home Products Corporation | 2-[1,3,2-dioxaphospholan-2-yloxy]ethyl compounds |
| US4904522A (en) * | 1988-07-26 | 1990-02-27 | Mobay Corporation | Process for the production of fiberglass mats |
| US5200267A (en) * | 1989-03-20 | 1993-04-06 | Medite Corporation | Fire-retardant synthretic board product |
| DE69005336T2 (en) * | 1989-03-20 | 1994-04-21 | Medite Europ | Device and method for the production of synthetic panels including fire-resistant panels. |
| ZA975821B (en) * | 1996-07-01 | 1998-07-01 | Ici Plc | Process for binding lignocellulosic material |
| DE69711384T2 (en) * | 1996-07-01 | 2002-10-17 | Huntsman Int Llc | METHOD FOR BINDING LIGNOCELLULOSIC MATERIALS |
| US6084003A (en) * | 1998-04-03 | 2000-07-04 | Kurple; Kenneth R. | Process for making foam using paint sludge |
| JP3522111B2 (en) * | 1998-06-16 | 2004-04-26 | セーレン株式会社 | Polyester fabric for inkjet recording and method for producing the same |
| EP0990680A1 (en) * | 1998-09-29 | 2000-04-05 | Haltermann AG | Process for the preparation of binder dispersions |
| AU731707B2 (en) * | 1998-10-13 | 2001-04-05 | Mitsui Chemicals, Inc. | Binder composition and process for the production of a board using the same |
| US6376566B1 (en) | 2000-06-14 | 2002-04-23 | Rhodia Inc. | Agricultural foam marker compositions and use thereof |
| DE102015113775A1 (en) * | 2015-08-19 | 2017-02-23 | Fritz Egger Gmbh & Co. Og | Broken dispersion for the hydrophobization of lignocellulose-containing material |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3317481A (en) * | 1963-12-27 | 1967-05-02 | Du Pont | Chemical compositions and process |
| AT270189B (en) * | 1966-03-17 | 1969-04-25 | Novopan Gmbh | Process for the production of panels or moldings by pressing, preferably hot pressing, a mass of wood chips, wood fibers or lignified raw materials mixed with binding agent |
| GB1523601A (en) * | 1975-03-12 | 1978-09-06 | Ici Ltd | Sheets or moulded bodies |
| DE2703271C3 (en) * | 1977-01-27 | 1980-02-14 | Basf Ag, 6700 Ludwigshafen | Preparation of aqueous isocyanate emulsions |
| DE2831674A1 (en) * | 1978-07-19 | 1980-02-07 | Basf Ag | AQUEOUS ISOCYANATE EMULSIONS FOR THE GLUING OF CHIPBOARDS |
| DE2832509C2 (en) * | 1978-07-25 | 1986-02-20 | Deutsche Novopan KG, 3400 Göttingen | Process for the production of chipboard |
| EP0013112A1 (en) * | 1978-12-27 | 1980-07-09 | Imperial Chemical Industries Plc | Emulsifiable compositions and aqueous emulsions of organic isocyanates, and process using them as binders for manufacturing lignocellulose sheets |
| DE2948015A1 (en) * | 1979-11-29 | 1981-06-11 | Basf Ag, 6700 Ludwigshafen | METHOD FOR PRODUCING AQUEOUS PARAFFIN DISPERSIONS IN THE PRESENCE OF CATIONIC POLYELECTROLYTES AS DISPERSING AGENTS |
| DE2921726A1 (en) * | 1979-05-29 | 1980-12-11 | Bayer Ag | AQUEOUS ISOCYANATE EMULSIONS AND THE USE THEREOF AS BINDERS IN A METHOD FOR PRODUCING MOLDED BODIES |
| DE2921681A1 (en) * | 1979-05-29 | 1980-12-11 | Bayer Ag | NEW EMULSIFIERS, AQUEOUS ISOCYANATE EMULSIONS CONTAINING THESE EMULSIFIERS AND THE USE THEREOF AS BINDERS IN A METHOD FOR PRODUCING MOLDED BODIES |
-
1982
- 1982-01-15 DE DE19823201111 patent/DE3201111A1/en not_active Withdrawn
- 1982-12-30 CA CA000418781A patent/CA1184334A/en not_active Expired
-
1983
- 1983-01-03 US US06/455,376 patent/US4472230A/en not_active Expired - Lifetime
- 1983-01-04 AT AT83100013T patent/ATE16098T1/en not_active IP Right Cessation
- 1983-01-04 EP EP83100013A patent/EP0084313B1/en not_active Expired
- 1983-01-04 DE DE8383100013T patent/DE3360993D1/en not_active Expired
- 1983-01-14 DK DK198300153A patent/DK172719B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DK172719B1 (en) | 1999-06-14 |
| US4472230A (en) | 1984-09-18 |
| ATE16098T1 (en) | 1985-11-15 |
| EP0084313B1 (en) | 1985-10-16 |
| DK15383D0 (en) | 1983-01-14 |
| DE3360993D1 (en) | 1985-11-21 |
| EP0084313A1 (en) | 1983-07-27 |
| DK15383A (en) | 1983-07-16 |
| DE3201111A1 (en) | 1983-07-28 |
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