CA2038332A1 - Preparation of homopolymers and copolymers of monoethylenically unsaturated dicarboxylic acids and use thereof - Google Patents

Abstract

- 29 - O.Z. 0050/41484 Abstract of the Disclosure: Homopolymers and copolymers of monoethylenically unsaturated dicarboxylic acids of K
7 - 50 which are useful as additives in textile and dishwashing detergent compositions in amounts of from 0.1 to 15% by weight are obtained by free radical polymeriza-tion of (a) monoethylenically unsaturated dicarboxylic acids, (b) hydroxy-C2-C4-alkyl (meht)acrylates and optionally (c) other water-soluble monoethylenically unsaturated monomers at a degree of neutralization of the acid group-contain-ing monomers during the polymerization of from 52 to 70%, and contain not more than 1.5% by weight of unpolymerized dicarboxylic acid.

Description

~03~ Z
O.Z. 0050/41484 PreParation of homoeolymers and co olymers of monoethylenically un~aturated dicarboxylic aclds and use thereof EP-B-0,075,820 disclose~ a process for preparing copolymers o~ monoethylenically unsaturated mono- and dicarboxylic aoids wherein monomer mixtur~s of from 10 to 60% by weight of a monoethylenically unsaturated dicar-boxylic acid, ~uch as maleic acid~ and from 90 to 40% by weight of a monoethylenically unsaturated monocarboxylic acid o~ from 3 to 10 carbon atom8~ such a~ acrylic acid, are polymerized in an aqueous medium at 60 - 150C and at a degree o~ neutralization of from 20 to 80% during the pol~merization reaction using from 0.5 to 5% ~y weight of a water-soluble initiator~ based on the monomers. Thi~
process give~ copolymers containing less than 1.5~ by weight of residual, unpolymerized dicarboxylic acid.
DE-A-35 12 223 di~closes the preparation of homopolymer~ and copolymars of maleic acid by copolymer-ization of maleic acid in an aqueous medium with or without other water-~oluble ethylenically un~aturated monomer~ in the pre~ence of polymexization initiators. In this proce~, maleic acid i9 ix3t neutralized with an alkali metal hydroxide or ammonia in a molar ratio of fxom 100 : 0 to 100 : g0 and then pol~merized by the ; 25 addition of a polymerization initiatorO Further alkali metal hydroxide or ~mmonia i~ addad to the reaction mixture in the cour~e of the polymerization, 80 that the molar ratio of maleic acid to ba~e i~ from 100 : 100 to 100 : 130. The polymerization i~ then completed. Accord-: 30 ing to the examples, however, the ratio o~ male~c acid to sodium hydroxide solution aft~r the polymerization has ended i~ not more than 1:1. The pol~mers thus preparable have a narrow molecular weight di~tribution and molecular weights within the range ~rom 200 to 20,000. According to said patent application, it i~ impo~ible to achieve a ~: high rate o~ polymerization out~ide the neutralization range specified for maleic acid. The copolymer~ are used , .
, -, , ~ ~ ; , 1' ~2~3~333Z
- ~ - O.Z. 0050/41484 for example as scale inhibitor~ fox boiler or desalina~
tion sy~tems, as detergen builders and as dispersants for inorganic pismen~s.
EP-A-O, 337, 694 concerns a proces~ fox preparing maleic acid polymers in the aci~ form having a number average molecular weight of from 300 to 5,000 and a narrow moleoular weight distribution (ratio of M~ : MN
less than 2.5) by polymerizing maleic: acid in an aqueous medium, optionally together with from S0 to 0.1% by weight of other water-soluble ethylenically unsaturated monomer~, i~ the presence of metal ions (eg. iron, vanadium and copper ions) in amounts of from 0.5 to 500 ppm and hydrogen peroxide in amounts of from 8 to 100 g/mole of monomer~ The polymers thus obtainable are u~ed as water treatment agents. It i~ true that according to the comparative example3 even an up to S0~ or 23 . 7~
neutralized maleic acid polymerize~ in the pre~ence of an :~ initiator sy~tem of hydrogen pero~ide and iron ions, but ~ the polymer~ obtained contain high re~idual level~ o ::~ 20 maleic acid.
:~ It i~ an ob~ect of the present invention to provide a ~rocQ~s for preparing homopolymer~ and copoly-mers of monoethylenically unsaturated dicarboxylic acid~
:: which converts a monoethylenically un~aturated dicarbox-: 25 ylic acid content of at lea~t 65% by weight into a polymsr containing not more than 1.5% by weight of residual monoethyl~nically un~atura~ed dicarboxylic acid monomer.
We have found that thi~ ob~ect l~ achieved according to the present invention by a proces~ for : preparing a homopolym2r or copolymer of a monoethyleni-cally un~aturated dicarbo~ylic acid having a ~ value of from 7 to S0 (determinad after H. Fikent~cher on the sodium salt of the polymer at pH 7 and 25aC in 1%
; 35 ~tren~th aqu90u~ ~olution) by free radical polymerization ' ~ of (a) a monoethylenically unsaturated C4-Câ-dicarboxylic :~ :

;~03~333~
- 3 - O.Z. 0050/41484 acid, (b) a hydroxy-C2-C4-alkyl acrylate or methacrylate and (c) another water-soluble monoethylenically unsaturated monomer in a weight ratio of (a) : (b) : (c) of (100 - 65) : ~0 -35) : (O - 35) in partially neutralized form in aqueous solution, which comprises setting the degree of neutra-lization of the acid group-containing monomer(s) to 52-70% during the polymerization, which in the case of the preparation of a copolymer of (a) with an acid group-containing monomer (c), when the degree of neutralization of monomer (a) at the ~tart may be as high as 85%, is achieved by using the acid group-containing monomer (c) in nonneutraliz~d form.
1~ The monomers of group (a) are monoethylenically unsaturated C4-C8-dicarboxylic acids. Suitable dicarbox-ylic acid3 are far e~ample maleic acid, fumaric acid, : itaconic acid, mesaconic acid, methylenemalonic acid and citraconic acid. I~ is of cour~a al~o po~sible to use ~0 dicarboxylic anhydrides which on ~is~olving in water convert into the acid form. Suitable anhy~ride~ of thi~
kind are for example maleic anhydride, itaconic anhydride and methylen~malonic anh~dride. Preferred monomers of : this group are maleic acid, fumaric acid and itaconic acid, especially maleic acid or the anhydride thereof.
I The monomer3 of group ta) are either homopolymerized or copolym~rized with one another or with monomexs of groups (b) and/or (c). In the ca~e of copolymer~, ~hey co~ain at least 65% by weight, pra~erably from 80 to 95~ by weight, of monomers of group (a) as copolymerized units.
The monomers of group (b) are hydro~y-C2~C4 alkyl acrylates and~or m~thacrylate~. Compounds o~ thi~ ~ype are for oxample 2-hydroxyet~yl acrylate, 2-hydroxyethyl methac~ylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, ~-hydxoxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl ~, : :
. . . -, ~[33~3332 - 4 - 0.2. 0050/41484 methac~ylate and mixtures thereof, which also includes all isomers and isomer mixtures. Preferred monomers of this group are hydroxyethyl acrylate, hydroxyethyl methacxylate, hydro~ypropyl acryla~e~ and hydroxypropyl methacrylate~. The monomers of group ~a) are copol~mer-ized with the monomers of group ~b) in a weight ratio of : (100 - 65) : ~0 - 35), preferably (99 - 80) ~ 20).
Monomers o group (c) are other water-soluble monoethylenically unsaturated monomer~ which are copoly-merizable with monomers (a) and (b~. Examples of monomers of group ~c) are C3-C1O-monocarboxylic acids, such as acrylic acid~ methacrylic acid, dLmethylacryrlic acid, ethylacrylic acid, allylacetic acid and vinylacetic acid.
Prefexence i~ given to u~ing from thi~ group of monomers acrylic acid~ methacryrlic acid and mixture~ thereo~.
Other suitable monomar~ (c) are ~ulfo-containing mono-mer~, eg. vinyl~ulfonic acid, allyl~ulfonic acid, meth-allylsulfonic acid, styrene3ulfonic acid, 3-~ulfopropyl acrylate, 3-sul~opropyl methacryrlate and acryrlamido-methylpropane~ulfonic acid, and also phosphono-containing : monomers, eg. vinylpho~phonic acid, allylphosphonic acid and acrylamidome~hylpropanephosphonic acid. It is also .~ pos~ible to use acid group-free water-soluble mono-~; ethylenically unsaturated monomers as monomers of group ~ 25 ~c) in the copolymerization, for example amides such as r~ acrylamide, msthacrylamide, N-alkylacryrlamides having ',r,~ ' fro~ 1 to 18 carbon atoms in the alkyl group, eg. ~-r~ methylacrylamide, ~-dim~hylacrylamide, N-tert-butyl-acrylamide and N-oc~adecylacrylamid~, N-vinylpyrrolidone, ~ 30 N-vinylcaprolactam, N-vinylimidazole, l-vinyl-2 methyl-.~ ~ imidazole,1-vinyli~idazoline,l-vinyl-2-methylvinylimid-`~ azoline, N-vinylformamide, N-vinyl-N-methylformamide, N-~:~ vinylacetamide, N vinyl-2-methylacetamide and mixtures .. thereof. The monomers of yroup (c) are copolymerized with :~. ; 35 the monomer~ of group (a) either alone or together with $ ~ the monomer~ of group (b). The weight ratio of (a) : ~b) $~ ~ : (C) in the copolymerization i8 (100 65): (O - 35):
~',.,:
"' `
$~

' ',; ~;

.,, .
.,:' . ' .~ . .

- 5 - O.~. 0050/41484 t0 - 35). If monomers of group (c~ are u~ed in the copolymerization, the amount based on 100 parts by weight of copolymer is prefexably from 1 ~o 20 parts by weight.
Preferred monomers o~ this group are acrylic acid, methacrylïc acid and acrylamidomethylpropanesulfonic acid.
To modify the copolymers, it i5 possible to include monomers of group ~d) in amounts of up to 5% by weight, based on the total amount of monomers used in the polymerization. The monomers of group (d) are cross-linker~, for example N,N-methyleneb;sacrylamide, esters of acrylic acid, methacrylic acid and maleic acid with polyhydric alcohols and polyalkylene glycol~, these esters having at lea~t two monoethylenically unsaturated double bonds, eg. glycol diacrylate, glycol dimethacry-late, glycerol ~riacrylate, glycerol trimethacrylatQ, polyethylene glycol diacrylate~ derived from polyalkylene glycols of molecular weight 96 - ca. 2,000, and al~o the corresponding polyethylene glycol dimethacrylatesl ~: 20 polyethylene glycol dimaleate~ o~ polyethylene ~lycols of i molecular weights of up to 2,000, glycol dimaleate and also doubly acrylated or methacrylated polyols, such a~
pentaerythritol and glucose. It is also po~ible to use cro~slinked divinylbenzene, divinyldioxane, pentaeryth-:~ 25 ritol diallyl ether and pentaallylsucrose. I cros~-linkers are included in th~ copolymeri2ation, they are prs~erably u~ed in an amount of from 0.05 to 5~ by weight, ba~ed vn the total amount of monomers u~ed in the polymerization.
- To prepare polymer~ having a particularly low K
value, the monomers are polymerized in the presence of regulators. Suitable ragulators are for example mercapto compound~, such as mercaptoethanol, mercap~opropanol, mercaptobutanol, merc~ptoacetic acid, mercaptopropionic acid, butylmercaptan and dodecylmercaptan. Other suitable regulator~ are allyl compound~ ~uch a~ allyl alcohol, hydroxylamine, formic acid, ethylene glycol, propylene ', ' , ~`

3~3;332 - 6 - O.g. 0050/41484 glycol r polyethylene glycol and polypropylene glycol having moleculax weights of up to 6,000 and secondary alcohols r sueh as isopropanol and sec.-butanol. If the polymerization is carried out in the presence of regula-tors, they are used in an amount of from 0.05 to 20% hy weight. It is of course al~o possible to carry out the polymerization in the presence of both regulators and monomers of group (d), the crosslinkers.
The monomers are subjected to a polymerization initiated with a free radical initiator. Suitable initia-tors for the polymerization are consequently all com-pounds which ~orm free radicals under the polymerization conditions, such a~ azo compound~ and peroxides. This also includes redox systems. Preference i9 given to water-soluble initiator~ such as persulfates r eg. sodium persulfate, potas~ium persulfatQ and ammonium persulfate, and hydrogen peroxide. Especially in tho~e ca~es where the polymerization i5 carried out at relatively low temperatures it i~ advantageou~ to use redox initiators ~ 20 to ~peed up the reaction. Such redox initiator system~
;~ comprise cu3tomary free radical compounds, such as peroxides, persulfates or percarboxylic acids, together with a reducing compound, sueh as ~odium hydrogen sul-fite, sodium di~ulfite, sodium dithionite, sodium formaldahyde ~ulfoxylate~ sulfur dioxide, ascorbic acid or mixture~ thereof. It i9 also posslble to use heavy m2tal~, such a~ iron, copper, nickel, chromium, manganese and vanadLum ion~, in the form of soluble salts as redox component. The heavy metal ion~ are added in amount~ of from 0.1 to 100, preferably from 0.1 to 10, ppm~ It is advanta~eous in ~ome in~tances to use not only reducing agents bu~ also heavy metal ions, If reducing a~ents are present in the catalyst sy~tem, their amount i~ fr~m 0.1 ~o 10, preferably from 0.2 to 5, % by weight, based on the monomers. ~he polymerization initiator3 are used in amounts of from 0,5 to 20, preferably from 2 ~o 13, ~ by weight, based on the monomersO If the homopolymers or ' ~

~C~3~
- 7 - O.Z. 0050/41484 copolymers are to have a relatively high maleic acid content, the amount of initiator used will be toward the ~op end of the above-described range, while copolymers which are to contain from 65 to about 80~ by wei.ght of maleic acid as copolymerized units are prepared using initiator quantities within the range from 0.5 to 12% by weight.
The polymerization is carried out with aqueou~
solutions of the monomers. The concentrations of the monomers in ~hQ aqueous solution is customarily from 10 to 70, preferably from 20 to 60, % by weight. The monomers are customarily polymerized within the tempera-ture range from 70 to 150C, preferably from 80 to 130C.
Particular prefexence i~ given to polymeri~ing under :: 15 boiling conditions of the reaction mixture. If the polymerization temperature is above the boiling point o:~
the reaction mixture, an appropriately designed p:ressure apparatus is u ed. ~he polymerization can of cour~e also be carried out under reduced pre~ure. However, it is m~st 8imply carried out at atmospheric pres~ure. A~ is cu~tomary with polymerizations, the polymeri2ation is carried out with the exclu ion of oxygen, for example in an inert gas atmo~phere, eg. under nitrogen. During the ~; polymerization it i~ ad~antageou~ to en3ure thorough :~ 25 mixing of the reactants. This can be achieved for example i~ any r3actor which is equipped ~ith a stirrer, for example a hor~eshoe stirrer.
According to the presPnt invention, tha degree of neutralization of the acid group-containing monomers is ad~usted to 52 - 70~ during the homopolymerization or copolymerizatLon, so that the polymer~ ob~ained after the polymerization ha~ ended are already partially neutral-: ized in that the acid group-containing monomer~ present a~ copolymeri~ed unit~ have been neutralized to 52 - 70%, proferably 55 - 65%.
: In preparing copolymers by copolymerizing mono-mer~ (a) with acid group-containlng comonomers (c) it is , .

~ :, ~)3833~
- 8 - O.~. 0050/41484 initially pos~ible to set a dPgree of neutralization of monomers (a) which is a~ove the range from 52 to 70% if the acid group-containing monomers (c) are sub~equently added to the initially charged monomers (a), being up to 85~ neutralized, in nonneutrali2ed form. After all the monomer (c) has been added this then too produces a partially neutralized copolymer having a degree of neutralization in respect of the copolymerized acid groups of from 52 to 70%, preferably from 55 to 65%. If copolymer~ are to be prepared ~rom monomers (a) and (b) or from (a) and acid group-free monomer ~c) and option-ally monomer (d) or from monomers (a) and (b), acid group-free monomers (c~ and optionally monomer~ ~d), it is preferable first to intro~uce ~he monomers of group ~a) in the form of a 10-70% strength aqueou~ solution having a degree of neutralization of from 52 to 70~, preferably from 55 to 65~, and then to add the comonomer~
and the initiator to the reac~ion mixture at a ra~e commensurate with the rate of copolymerization; that is, to add the comonomers and the initiator to the reaction mixture at ~uch a rate that the polymerizatio~ reaction remain~ readily controllable, ~o that the heat of poly-merization can be safely removed.
Another way of maintaining the degree of neutral-~ 25 ization within the abovementioned range during the : copolymerization of monomer~ (a) with acid group-contain-ing monomers (c) and optionally (b) and td) i8 to neutra-li~e the monomer~ (a3 in aqueous solution to 52 - 70~ and to add the acid group-containing monomers (c~ and option-ally the other comonomer~ to the initially introduced aqueous solution of the partially neutrali2ed monomar3 (a) together with a base, ~o that the acid group-contain-ing monomers (c) likewi~e ha~e a degree o~ neutralization wi~hin the range from 52 to 70%, preferably from 55 to 65%. However, the acid group-containing monomer~ (c) may al~o be added to the initially introduced aqueous, p~rtially neutralized solution of monomer (a) in an .

' ' ' ~0~332 _ g - O.Z. 0050/41484 already partially neutralized form with a degree of neutralization which is within the specified range. And the acid group containing monomer (c) may also be added to an at least 60~ neutralized monomer (a) with the lower degree of neutralization of 52~. The only requirement is tha~ the acid group-containing units (c) and (a) present in the copolymer ha~e a total degree of neutralization of from 52 to 70%. But in some in~tances it may also be advanta~eous to add the acid group-containi~g monomers (c) in a partially or completely neutralized form, in which case, however, the initially introduced monomers (a) must then be neutralized to a correspondingly smaller percentage.
The neutralizing agent used is an al~ali metal base, ammonia or an amine. Preference is given tc~ using sodium hydroxide and potassium hydroxide. Suitable amine~ :
for use a-~ neutralizing agents are for example ethanol-amine~ dia~hanolamine, triethanolEmine, morpholina and mixtures thereo~

2~ ~o prepare colorles3 or only sli~htly colored homopolymer~ and copolymers from monom~rs (a) to (d), the polymerization is advantageously carried out in the . presence of water-soluble phosphorus compounds in which the phosphoru~ has an oxidation number of from 1 to 4, the water-soluble alkali metal or ammonium salts thereof, ~;. water-soluble PO(O~)2-containing compounds and/or water-: soluble ~alts thereof. Preference i~ given to using phocphorouR acid. The contemplated phosphoru~ compounds are used for reducing the discoloration of polymer~ in .~;. 30 amount~ of from 0.01 to 5~ by weight, based on the ~:~ monomer~ used. The contemplated pho~phorus compounds are described in con~ection with other polymerization pro-ces~es in EP-A-0,17S,317.
The process according to the pre~ent invention : ~ 35 gives polymers having R value~ of from 7 to 50, prefer-ably from 8 to 30 (measured at 25C on 1% streng~h aqueous solution~ of the polymers ad~usted to pH 7 with ,....

,~

lO - O.Z. 0050141484 sodium hydroxide solution). The homopolymers and copoly-mers obtainable by the process according ~o the pre3en~
invention contain relatively low levels of residual monomers of group (a). The residual monomer level of S maleic acid i5 for example not more than loS%~ base~ on solids. The polymer~ thus obtainable can therefore be directly used for the intended purpo~e~ or after complete neutralization. The homopolymers and copolymers are usable for example as additives in fabric and dishwashing detergent compositions in amounts o~E from O.l to 15~ by weight, in either case based on the formulation as a whole~
Dishwashing compositions contain for example from 5 to 20% by weight of an ammonium or alkali metal carbon-ate or of an ammonium or alkali me~al ~ulfate, at least 2~ ~y weight o~ an alkali metal 3ilicate and from 0.5 to 8~ by weight of a low-foam surfactant and al~o, as a - further essential component, a polymer obtainable by the ~: proces~ according to the present invention, ~hey may ; : 20 contain up to 94~ by weight of sodium ~ilicate and up to ~ about 50% by weight of an ammonium or alkali metal ;~ carbonate or ~ulfate. They may al~o contain compoundY
which give off active chlorine, for ex~mple the potassium ~ or sodium ~alt~ of dichloroisocyanurate, in which case `. 25 the active chlorine content of the formulation may ba up to 3% by weight. In addition, gluconic acid or glucoheptonic acid an~ the alkali meta~ salts thereof may be pre~ent in amounts of up to 20% by weigh~. Dishwashing detergent compo3itions may contain still other cu~tomary additives, ~or example antifoams~ dy2s, ~cents, dust-proofing agents and commercial polymer~, for example polyacrylate~ or copolymers of 70% by weight of acrylic acid and 30% b~ weight o maleic acid9 in tha cu~tomary concentrations. Since ths compo~itions of dishwa~hing agents vary widely, the above statement~ are to be treated as mexely illustrative.
~he homopolymer~ and copolymer~ obtainable by the ,., ~

~: :

~03~33~
~ O.Z. 0050/414~
process according to the present invention can also be used in textile washing detergent compositions, herein-after sLmply called detergent~. In many cases it is necessary for this purpose that the polymer solutions obtained in the polymerization can be dried to a powder or granules in customary dryers ~uch a~ drum dryers, spray dryers or combined spray/fluidized bed dryers.
The polymers act as incru~ation inhibitors and pigment soil dispersants in the detergents. They can be u~ed not only in liquid but also in pulverulent deter-gents and cleaners. Compared with the copolymers of monomers ~a) and acid group-containing monomers ~c) disclosed in EP-B~0 025 551, they ~how in particular Lmproved compatibility in liquid detergent formulations.
~he compositions of detergant formulation3 can vary widely. The same i8 true of the compo~itions of clea~er formulation~. Detergent and cleaner formulation~
customarily contain surfactants with or without builder~.
This applies not only to liquid but al90 to pulverulent detergent and cleaner foDmulation~. Examples o compo~i-tions of dete~gent formulations customary in Europe, the VSA and Japan are found in tabla form for example in Chemical and Engn. New~ 67 (1989)~ 35, and in Ullmann3 Encyklop~die der techni~chen Chemie, Verlag Chemie, ~; 25 Weinheim 1983, 4th edition, page~ 63-160.
The above-Ae~cribed polymers are u~ed according to the pre e~t invention in detergents which contain up to 45% by weight of phosphate, although the u~e of the polymer3 in detergent~ having a reduced pho3phate content (~o be under~tood a~ meaning a phosphate content of less : than 25% by weight of Rodium tripho~phate) or in phos-phate-free d~terg2nt~ and also in cleaners is preferred.
The polymer~ may be added to the detergent formulation in the form of granule~, a~ a pa~te~ a~ a highly vi3cou~
mass, a~ a disper3ion or aq a solutiQn in a olvent. The polymer~ can al~o be adsorbed at the ~urface o~ colorle~s diluents, for exa~ple ~odium sulfate, or b~ilder~ (zeo-'~
: : , `

~3833;~
- 12 - 0.2. 0050/41484 lites or bentonites) and also other solid ingredients of the detergent formulation.
Detergent formulations and cleaner formulations are pulverulent or liquid. They may vary in composition by region and according to the specific intended use.
Univer~al household detergents for drum type washing machines of the type widely used in Europe usually contain from 5 to 10~ by weight of anionic suractants, from 1 to 5% by weigh~ of nonionic surfac~
tants, from 1 to 5~ by weight of foam regulators, such as silicone oils or soaps, from 0 to 40% by weight of a water softener, such as sodium carbo~ate or pentasodium triphosphate, which may be replaced in whole or :in part by the compounds according to the present invention, from 0 to 30% by weight o~ an ion exchanger such as zeolite A, from 2 to 7% by weight o sodium silicate as co:rrosion inhibitors, from 10 to 30~ by weight o~ bleaching agents, ~uch as sodium perborate, sodium perGarbonate, organic peracid~ or salt~ thereof, ~rom 0 to 5% by weigh~ of bleach activators, such a~ tetraacatylethylenadiamine, pentaacetylglucose, hexaacetyl~orbi~ol or acyloxybenzene-~ulfonate, stabilizer~, such as magne~ium silicate or ethylenediaminetetraace~ate, grayne3~ inhibitors, such as carbvxymethylcellulo~e, methylalkylcellulose and hydroxy-~- 25 alkylcellulose, polyglycols grafted wi~h vinyl acetate, oligomeric and polymeric terephthalic acid/ethylene glycol/polyethylene glycol est8r3, enzymes, fluo:rescent whitening agents, scents, fabric ~oftener~, dyes, and diluents.
~ By contra~t, the heavy duty detergents which are widely u8ed in the USA, Japan and ne.ighborlng countries in tub type washing machine~ axe uAually frae of bleach ing agents, but on the other hand their anionics con~ent i~ tWQ or ~hrse times higher and they contain more wash alkalis, such a~ sodium carbonate and sodium silicates (in general up to 25~ by weight), but they usually also lack the bleach activators and xtabilizers. The levels of : .. : , ~: . : :

: . :
,~ . .

2~3~3332 - 13 - O.Z. 0050/~14~4 surfactants and other ingredients can be apprec.iably higher in the case of detergent concentrates r which are available with little or no diluent. Detergents for easy-care and colored fabrics, wool detergents and manual wash S detergents likewise usually contain no bleaching ag~nts and low levels of alkaline ingredients together with an appropria~ely increased ~urfactant co:ntent.
Detergents for the commercial sector are designed for the special conditions of industrial wa~hing ( 50~t water, continuQus washing) which make it possible to customize the de~ergent to the type of article being washed and to the nature of the soil. Combinations are therefore used in which one ingredient predominates or others are completely ab~ent on~y to be added separately lS whe~ requixed. For this reason the surfactants, builders, alkalis and hleaching agents of these detergents vary within wide limit~.
5uitable anionic ~urfactants for the afore-mentioned pulverulent detergent~, or washing powder~, are for example sodium alkylbenzenesul~onates, fatty alcohol ~ulfates and fatty alcohol polyglycol ether sulfate Individual compound~ of this type are for example Ca-Cl2-;alkylbenzenesulfonate~, Cl2-Cl6-alkanesulfonates, Cl2-Cl6-alkyl~ulfates, Clz Cl6-alkylsulfo3uccinate~ and sulfated etho~ylated C12-C16-a}kanols. Other suitable anionic ~uractants are ~ulfated fatty acid alkanolamines, ~-~ulfo fatty acid esters, fatty acid monoglycerides or reaction products of from 1 to 4 mol of ethylene oxide with primary or secondary fatty alcohols or alkylphenols.
F~rther suitable anionic surfactan~s are fatty acid ester~ and fatty acid amides of hydroxy- or amino-carbox-ylic or -sulfonic acids, for sxample the fatty acid sarcoside~, glycolates, lactate~, tauridea or isethion-akes. The anionic 3urfactants can bo present in the form of the ~odium, potassium and ammonium salt3 and al~o aa solubla salta of organic bases, such as mono-, di- or triethanolamine or other substituted amines. Tha group of .: . . , :
-' ' ' ~ ~ ' :, .

~31~33~
- 14 - o.Z. 0050/41484 anionic ~urfactants also includes the ordinary soaps, ie.
the alkali metal salts of natural fatty acid~.
Suitable nonionic surfactants ~nonionics) are for example addition products of from 3 to 40, preferably from 4 to 20, mol of ethylene oxide with 1 mol of fatty alcohol, alkylphenol, fatty acid, fatty amine, fatty acid amide or alkanesulfonamide. The abovementioned addition products of ethylene oxide may additionally contain up to 90% by weight of propylene o~ide as copolymerized unit, based on the polymerized ethylene oxide and propylene oxide. The addition products which contain ethylene oxide and propylene oxide may be modified by incorporation of butylene oxide in amounts of up to 60% by weight, based on the total alkylene oxide content. Of particular importance are the addition products of 5 ~o 16 mol of ethylene oxide with coco or tallow fatty alcohol~, with oleyl alcohol or with synthetic alcohvls of from ~ to 18, preferably fxom 12 to 18, carbon atoms, and also with mono- or dialkylphenols having from 6 to 14 carbon atoms in the alkyl moietie~. Besides these water-soluble nonionic~, however, it is als~ pos~ible to usa water-insoluble or incompletely water-soluble polyglycol ethers havin~ from 1 to 4 ethylene glycol ether moieties in the molecule, in particular if they are used together with water-soluble nonionic or anionic surfactants.
Further usable nonionic surfactants are th~
water-~olubl~ addition products of ethylene oxide with poIypropylene glycol ether~, alkylenediaminopolypropylene glycol and al}~ylpolypropylene glycol~ having from 1 to 10 carbon atoms in the alkyl chain which contain from 20 to 250 ethylene glycol ether group~ and from 10 to 100 propylene glycol ether groups, the po1ypropylana glycol ether chain acting a~ the hydrophobic moiety.
It is also po~sible to use nonionic surfactants of th~ type of the amine oxides or sulfoxides.
The foaming power of the 3urfactants can be increased or reduced by combining suitable surfactant '':

, ~.

,,. , ~ .

8~
- 15 - O.Z. 0050/41484 types. A reduction can also he achieved by adding non-surfactantlike organic substances.
Further possible formulation ingredients of detergents include monomeric, oligomeric and polymeric phosphonates, ether sulfonate~ based on unsaturated fatty alcohols, eg. oleyl alcohol ethoxylate butyl ether, and alkali metal salts thereof. The~e substances can be characterized for example with the aid of the formula RO(CH2CH2O)n-C4H~-$O3Na, whare n is from S to 40 and R is oleyl.
The above-described pol~mers may also be used as additives in liquid detergents. Liquid detergents contain liquid surfactants or else solid surfactants which are soluble or at least dispersible in the detergent formula ~ion. 5uitable surfactan~s for this purpose are those products which are also used in pulverulent detexgent~, : and also liquid polyalkylene oxides or polyalkoxylated compounds. If the pol~mers are not directly miscible with the other constituent~ of the liquid detergent, it i~
possible to prepare homogeneou~ mixtures with ~he aid of ' ~ a small amount of a ~olubilizer~ for example water or a water-miscible organic 301vent ~ eg . isopropanol, ' methanol, ethanol, glycol, diethylene glycol o.r triethyl-; ene glycol or correspondlng propylene glycol~. The amount ~ 25 of surfactant in liquid deterqent3 is within the range } ~rom 4 to 50~ by weight, ba~ed on the formulation as a ¦ ~ whole, ~lnce in liquid detergent~ too the proportions of the ingredient~ vary within wide limits according to regional market conditions or the intended use.
- Liquid detergent3 may contain water in amounts of ' from 10 to 60, preferably from 20 to 50, ~ by weight. But they can al80 be free of water.
Water-free liquid datergent~ may al~o contain peroxo compounds ~or bleaohing in suspended or di~per3ed form. Examples of suitable peroxo compounds are: ~odium perborate, peroxocarboxylic acids and polymer~ having i; ~ som~ peroxo-containing group~. Liquid detergent~ may al90 .

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contain hydrotropes . These are compounds such as 1, 2-propanediol, cumenesulonate and toluenesulfonate. If such compound~ are used for modifying a liquid detergent, their amount is from 2 to 5~ by weight, ba~ed on ~he total weight of the liquid detergent. Xn many cases an addition of complexing agents ha~ alqo proved advantage-ous for modifying pulverulent and liquid detergents.
Complexing agents are for example ethylenediaminetetra-acetic acidr nitrilotriacetate and isoserinediacetic acid and also phosphonates, such as aminotrismethylenephos-phonic acid, hydroxyethanediphosphonic acid, ethylene-diaminetetraethylenephosphonic acid and salts thereof.
Complexing agents are used in amounts of from 0 to 10~ by weight, bas~d on the detergent. Detergen~ may also contain citrates, di- ox triethanolamine, clouding agents, optical brighteners, enzymes, per~ume oils and dyes. These sub~tances, i~ they are used for modifying a liquid detergent, together account for up to 5% by weight. Detergents are preferably phosphAte-free. How-ever, they may also contain phosphatas, eg. penta~odium triphosphate and/or tetrapotas~ium pyrophosphate. If ; phosphate~ are used, they account for up to 45, prefer-ably up to ~5, ~ by weight of the total formulation of detergent.
The polymer~ oan al~o combine with o~her known detergent addi~ives (for exaMple grayness inhibitors, clay di~per~ant~, ~ubsta~ces which enhanc~ prLmary detergenGy, color transfer inhibitors, bleach activators) in pulveruIent and liquid deteryent~ (phosphate-contain-ing and pho~phate-free) to create synergistic effectY
~oosting not only the grayness inhibition but also the action of the o~her detergent additive.
The K values were determined by the method of H. Fikentscher, Cellulosechemie 13 (1932), 58 - 64, 71 -74; K=kx103. The measurement~ were carried out on 1%
strength aqueous solution of the sodium salt~ of the polymers at 25C and pH 7. The re3idual level~ of mono-`.: '.' ~ , 2~3~3~
17 - O.Z. 0050/~1484 meric maleic acid in the polymers were detenmined polaro-graphically. The percentages of residual maleic acid in the polymer are expressed in terms of solids. The per-ce~ages are by weight.
EXAMPLES 1 ~O 4 AND COMPARATIVE EXAMPLE 1 A heatable reactor which is equipped with a stirrer, a reflux condenser, a thermometer, an addition means and a nitrogen inlet i~ charged with 300 g of water, 380.17 g of maleic anhydride, 3 g o 50% strength aqueous phosphorous acid, 20 ml of a 0.035% ~trength aqueous solution of ammonium iron(II~ sulfate and the amount of sodium hydro~ide mentioned in Table l, and this : initial charge i5 heated to the boil under nitrogen. The boiling ~olution, which is being stirred continuously, is admixed in the cour~e of 5 hour~ with a 301ution of 50 g of hydroxypropyl acrylate in 80 g o water and separately therefrom in the course of 6 hours with 266 g of 30~
stren~th hydrogen pexoxide. The polymerization is carried out at the boiling point of the reaction mixture. After all the hydrogen peroxide ha~ been added, the reaction mixture i5 heated at the boil for a ~urther 2 hours. It is then neutralized to pH 6.8 by adding the amounts of : 50% strength agueou-~ sodium hydroxide ~olution indicated in Table 1. Table 1 a}so indicates the 301ids content~ of the polymer solutions, the K value~ of the polymer~ and the level~ of unpolymerized maleic acid in the copoly-mers.

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- 18 - O.Z. 0050/41484 Example NaOH quantity NaOH 50~ Solids K Residual No~ Degree strength content value maleic of or acid 5neutral- neutral-ization izing the polymer solution [amount ~g] ~]in ~] [%] r%~
.
l 17~.7055 115 45.~0 0.56 2 186.2~60 g0 45.611.6 0.2~
3 201.7065 75 4~.810.5 0.71 ~ 217.2470 5~ ~5.410.2 1.4 Compara-tive Example 1 155.17~0 139 43.~11.1 2.29 ~XAMPLES 5 TO 10 AND COMPARATIV~ EX~MP1ES 2 TO 4 : The reactor de~cribed in Example 1 is charged in each ca~e with 300 g of water, 338 g of maleic anhydride ; and the ~mount Qf ~odium peroxide mentioned in Table 2, and ~he content~ are heated to the boil. The boiling i ~ mixture i8 admixed in the course o 5 hours with a : ~ solution of ~00 g of acrylic acid in 110 g of water and separately therefrom in the cour~e o~ 6 hour~ with a :~ solution of 20 g of sodium persulfate in 7~ g of water and a solution of 66.6 g of 30% strength hydrogen pero~-ide in 23.34 g o~ water at a uniform ratej and the polymeriza~ion is carried out a~ the boiling point of the ~ r~action mixture. After all the ini~iator ha~ been added, : the raaction mixture is heated at the boil for a Eurtheer 2 hour~, This produces clear, yellowi~h polymer solution~
whose solids contents are indicated in Table 2. T~ble 2 also indlcate~ the ~ values of the polymer~ and the 20~333Z
- 19 - O.~. 0050/41484 reiidual levels of maleic acid.

Example Amount of NaOH
No. added to initial charge Degree of Solids K Residual ~: nPutralization content value maleic rg] ~ acid of on initial com-charge pleted ~ addltion [%] [%]

: 5 231.77 84 ~9.9 53.3 17.2 1.00 6 221.74 80 66.~ 52.8 18.1 ~).47 ~: 7 213.84 77.5 64.5 52.9 2~.0 0.16 8 20~.g~ 75.~ ~2~4 52.6 18.7 0.35 :: 9 193.14 70 5~.2 52.6 ~0.8 0.55 ~0 17g.35 65 54.2 52.5 20.4 1.4 ;~ 20 Compara-tive:
~xample No.
248.33 90 7~.g S3.7 15.7 1.87 i! ~ 3 165-55 60 49-5 52.1 20.0 4.39 25~ 4: 137.96 50~ 41.6 49.8 15.0 11.30 ~.
: : EXA~P~E 11 ~:
The reactor ~pecified in Exampl~ 1 i9 charqed :: with 270 g of water~ 401.3 g of maleic anhydride and 213.42 g o 30dium hydroxide, and this initial charge i~
heated to the boil. Immediately the mixture begins to ~; : boil it is admixed in the cour~e of 5 hour~ with a olution o~ 25 g of acrylic ~cld in 80 g of water and in the cour~e of 6 hours with a ~olu~ion of 50 g of sodium per~ulfate in 120 g of water and ~eparately therefrom with 100 g of 50% ~trength hydrogen peroxide at uniform ~, ratQS t and~polymerized at the boiling point. After the ~:" ~

;~)38332 - 20 - o.æ. 0050/41484 initiator has been added, the reaction mixture is heated at the boil for a further 2 hours and then neutralized with lO0 g of 50~ strength aqueous sodium hydroxide solution. The degree of neutralization of the initial charge was about 65%. After all ~he acrylic acid had been added, the total degree of neutralization of the carboxylic acid groups in the copolymer was 62.5~. The resulting clear brownish solution hacl a solid~ content of 53.4~. ~he copolymer had a K value of 12.1 and contained 0.12% of monomeric maleic acid.

.` The reactor described in Example 1 is charged with 3~0 g of water, 38S g of m~leic anhydride, 7 ml of a 0.1% strength aqueous ~olution of ammonium ixen(II~
~ulfate and 193.15 g of sodi~m hydroxide, and this initial charge i~ heated to the ~oil. Immediately the mixture begin~ to boil, it is admixed in the course of S
hours with a solution of 50 g of acrylic acid, 95.35 g of 58% strength aqueou~ solutLon of the ~odium salt of acrylamidomathylpropane~ulfo~ic acid and 30.fi g of water and in the course of 6 hours from the start of boilin~
~ith a ~olution o 40 g of ~odium per~ulfate in 12V g of water and 133.33 g of 30% strength hydrogen peroxide at unlform rate~. After all the initiator has been added, 2~ the re~ction mixture i~ heated at the boil ~or a further ;~ hour and then neutralized with 50~ strength aqueou sodium hydroxide solution to pH 7Ø The sli~htly cloudy brown ~olution ~hus obtainable has a solid~ content of 50.8~. The copol~mer ha~ a K value of 13.3 and contain~
1;06~ of monomeric maleic acid.
~ EXAMPLE 13 : Application testing of the polymers a~ di~hwashing formulation additives ~ he following pulverulent di~hwashing formulation wa~ used to test an example according to the pre~ent . invention again~t comparative example~.
;. 32 part~ of sodium sulfate , ~ .

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- 21 - O.Z. 0050/41~84 55 parts of sodium metasilicate (anhydrous) 5 parts of sodium carbonate (anhydrous) 3 parts of the addition product of 2 mol of ethylene oxide and 4 mol of propylene oxide with 1 mol of a Cl3/C~5 fatty alcohol 5 parts of polymer The formulation was in each ca~e obtained by mixing the abovementioned products. The polymer product tested is specified below in the Table. To test each individual formulation, 2 g of the formulatiQn were used per liter of tapwater ~18 German hardness), and the aqueous solution of ~he formulation was hea~ed to 80C.
Then sets of flatware were immersecl, the solution was stirred with a magnetic stirrer for S minutes/ and t~e flatware was left to stand in the aqueou~ dishwasher liquor at 80C for a further S minutes. Then the flatware was dried unrinsed at 23C and the film left, if arly, waQ
rated on a scale from 1 to 5, where 1 denote~ a very poor result, ie. a clearly visible white film, while 5 clenote~
a very good result, ie. no film at all. qlhe polymAr~ used in the indiyidual formulation~ and the result~ are indica~ed in Table 3.

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i~38332 - 23 - O.Z. 0050/414~4 Testing of polymers as detergent additives The comparison is against a commercial copolymer of 70% by weight of acrylic acid and 30% by weight of maleic acid in the form of the sodi~ salt of K 60. This copolymer will hereinafter be referred to a~ comparati~e polymer 1.
The performance charact~ri~tics tested are the incrustation-inhibiting effect and the soil-dispersing ': 10 effect ~clay dispersion test).
: Incru~tation inhibitor effect To test the incrustation-inhibiting effect of the polymers described, each polymer WAS incorporated into a phosphate-~ree washing powder. This deterg~nt formulation was used to wash te~t abrics made of cotton. The number : of wash cycles used was 10. After each cycle the fabrlc wa~ ironed dry. Following this number o washes the a~h ;: content of each ~est fabric wa~ de~ermined by ashing the ;; ~abric. The greater the e~fectiveness of the polymer in the ~etergent, the lower the a~h content of the te~t .` fabric.
Experimental conditions for determining incru~tation:
Apparatus: ~aunder-0-Meter from Atlas, ~: Chicago 25 Number of wa~h cycle~ 10 Waqh liquor: 250 g, water used containing 4 . : mmol of hardnes per liter (molar ratio ef calcium to magnesium = 3 : 1) Washing time: 30 min at 60~ (including heating up time) Detergent dosage: 8 g/l Cotton fabric: 20 g "~
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, ~ ~ : " ~ , , ~ , , , ~0~ 32 - 24 - O.Z. 0050/41484 Detergent (phosphate-free) 12.5% of dodecylbenzenesulfonate ~50%) 4.7~ of a C13/CI5 oxo process alcohol polyglycol ether containing 7 ethylene oxide units 2.8~ of soap 25% of zeolite A
12% of sodium carbonate 4% of ~odium di~ilicate 1% of magnesium silicate 20~ of sodium perborate 5% of copolymer of operative or comparative exampls (calculated a~ 100% ~trength) O.6~ of odium carboxymethylcellulose Remainder to 100%: sodium sulfate 15 Effectiveness of polymers in respect of incrusta~ion inhibition Copol~mer added te Ash content detergant formulation ~
_ _ No polymer added 1.~9 Comparative polymer 1 0.57 Polymer o~ Example 8 0.59 Polymer ef Example 9 ~.49 ~'.
Clay disper3ion ~h2 removal of particulate soil from fabric ~uraces i~ augmented by the pre~ence of polyelectro-lytes. The~e polyelectrolyte~ have the import~nt task of : stabilizing the di~per~ion which form~ on detachment of : the particle~ from the fabric surface. The stabilizing effect of anionic disper~ants i~ due to the fact that the adaorption ~f disper3ant molecule~ at the particle surface increase~ their ~urface charge and the repul~ion energy. Further factors having a bearing on the stability of the di~perslon includa ~teric effects, the tempera-t~re, the p~I and the e1ectrolyte concentration.

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~1338332 - 25 - O.Z. 0050/41484 The clay dispersion (CD) test described herein-after provides a simple means for testing the dispersing power of various polyelectrolytes.
CD test The model ~mployed to represent particulate soil is finely ground china clay SPS 151. 1 g of clay is thoroughly dispersed in 98 ml of water in the presence of 1 ml of a 0.1% strength sodium salt solution of the polyelectrolyte in a graduated cylinder (100 ml) for 10 minute~. Immediately after stirring, a 2.5 ml s~nple is taken from the center of the graduated cylinder and diluted with water to 25 ml to measure the cloudine~s of the di.~persion with a turbidLmeter. Further samples were taken after the dispexsion had stood for 30 and 60 : 15 minutes and assessed turbid~metrically. The cloudi.ne~s of the disper~ion is reported in N~Us (nephelometric turbidity units). The slower th2 rate of settling o f the ~ dispersion during storage, the higher th~ measured :~ turbidity values and the stabler the di~per~ion.
The second physical variabls determined is the disper~ion constant r~ which describes the time course of the sedimentation proce3s. Since the ~edimentation process can be describe~ to an approximation with a monoexponential time law, r indicate~ the time within which the turbidi~y drop~ to l/e-th of the original ~tate at time t = 0.
~he higher r, the ~lower the rate of ~edimenta-~ tion of the di~persion.
:: Clay disper3ion test S~b~ance tested C~oudine~ in ~TU~ Di~persion after ~torage con~tant T
at once 30 min. 60 min.

Without polymer 600 37 33 41.4 Comparative polymer 1 540 470 380 g7.2 Polymer of Example 8 6~0 550 5~0 234.9 Polymer o~ Example 9 600 540 500 261.0 '~

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- 26 - O.Z. 0050/41484 The superiority o~ the copolymers according to the present invention over a commercial copolymer having a lower maleic acid content is evident. While the incrusta-tion inhibition effects are approxLmately the same, the copolymer according to the present in~ention is dis-tinctly more effective in the clay dispersion test, a measure of primary detergency.

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Claims (5)

1. A process for preparing a homopolymer or copoly-mer of a monoethylenically unsaturated dicarboxylic acid having a K value of from 7 to 50 (determined after H. Fikentscher on the sodium salt of the polymer at pH 7 and 25°C in 1% strength aqueous solution) by free radical polymerization of (a) a monoethylenically unsaturated C4-C8-dicarboxylic acid, (b) a hydroxy-C2-C4-alkyl acrylate or methacrylate and (c) another water-soluble monoethylenically unsaturated monomer in a weight ratio of (a) : (b) : (c) of (100 - 65) : (0 -35) : (0 - 35) in partially neutralized form in aqueous solution, the degree of neutralization of the acid group-containing monomer(s) being set to 52-70% during the polymerization, which in the case of the preparation of a copolymer of (a) with an acid group-containing monomer (c), when the degree of neutralization of monomer (a) at the start may be as high as 85%, is achieved by using the acid group-containing monomer (c) in nonneutralized form.

2. A process as claimed in claim 1, wherein a copolymer is prepared from monomers (a) and (b) in a weight ratio of (a) : (b) of (99 - 65) : (35) at a degree of neutralization of monomer (a) of from 55 to 65%.

3. A process as claimed in claim 1, wherein a copolymer is prepared from monomer (a) and (c) in a weight ratio of (a) : (c) of (99 - 65) : (35) by introducing the monomer (a) into the polymerization reactor, neutralizing it up to 85% with an alkali metal bass, ammonia or an amine and then adding an initiator and the acid group-containing monomer (c) in nonneutral-ized form at a rate commensurate with the rate of poly-merization.

4. A process as claimed in claim 1, wherein a copolymer is prepared from monomers (a), (b) and (c) in - 28 - O.Z. 0050/41484 a weight ratio of (a) : (b) : (c) of (99 - 65) : (1 - 35) : (1 - 35) at a total degree of neutralization of the acid group-containing monomers of from 55 to 65%.

5. A textile or dishwashing detergent composition containing from 0.1 to 15% by weight, based on the formula-tion as a whole, of a homopolymer or copolymer of a mono-ethylenically unsaturated dicarboxylic acid having a K
value of from 7 to 50 (determined after H. Fikentscher on the sodium salt of the polymer at pH 7 and 25°C in 1%
strength aqueous solution), obtainable by free radical polymerization of (a) a monoethylenically unsaturated C4-C8-dicarboxylic acid, (b) a hydroxy-C2-C4 alkyl acrylate or methacrylate and (c) another water-soluble monoethylenically unsaturated monomer in a weight ratio of (a) : (b) : (c) of (100 - 65) : (0 -35) : (0 - 35) in aqueous solution, with a degree of neutralization of the acid group-containing monomer(s) of 52-70% during the polymerization, which in the case of the preparation of a copolymer of (a) with an acid group-containing monomer (c), when the degree of neutralization of monomer (a) at the start may be as high as 85%, is achieved by using the acid group-containing monomer (c) in nonneutralized form.