EP0367049A2 - Use of partially esterified copolymers in liquid detergent compositions - Google Patents

Abstract

The use of partially esterified copolymers which can be obtained by copolymerisation of (a) at least one C4- to C28-olefin and (b) ethylenically unsaturated dicarboxylic anhydrides with 4 to 8 C atoms in the molar ratio 1:1 and subsequent partial esterification of the copolymers with reaction products of (A) C1- to C30-alcohols, C8- to C22-fatty acids, C1- to C12-alkylphenols or secondary C2- to C30-amines with (B) at least one C2- to C4-alkylene oxide or tetrahydrofuran in the molar ratio (A):(B) of 1:2 to 50 and hydrolysis of the anhydride groups of the copolymers to carboxyl groups, where the partial esterification of the copolymers is continued until more than 5 to 50% of the carboxyl groups in the copolymers are esterified, as additive to liquid detergent compositions in an amount of 0.1 to 20% by weight and liquid detergent compositions which contain the partially esterified copolymers.

Description

EP-PS 0 116 930 describes water-soluble copolymers of 40 to 90% by weight of at least one ethylenically unsaturated monocarboxylic acid with 3 to 5 C atoms and 60 to 10% by weight of at least one ethylenically unsaturated dicarboxylic acid with 4 to 8 C atoms and / or their corresponding dicarboxylic acid anhydrides are known, in which 2 to 60% by weight, based on the total weight of the carboxylic acids or carboxylic acid anhydrides, are esterified with alkoxylated C₁ to C₁₈ alcohols or C₁ to C₁₂ alkylphenols. The partially esterified copolymers and their water-soluble salts are used, inter alia, in amounts of 0.5 to 10% by weight also used in liquid detergent formulations. As is known from this reference, the compatibility of the partially esterified copolymers of at least one monoethylenically unsaturated monocarboxylic acid and at least one monoethylenically unsaturated dicarboxylic acid is significantly more favorable than that of the non-esterified products, so that there are fewer phase separations. However, the partially esterified copolymers of the type described are not stable to hydrolysis, so that they hydrolyze in liquid detergent formulations. As a result, inhomogeneities occur, which can even go so far as to result in phase separation of the liquid detergent.

From EP-A-0 237 075 liquid detergents are known which contain at least one nonionic surface-active agent in an amount of 5 to 25% by weight, 2 to 25% by weight of a builder, approximately 1 to 10% by weight of C₄- to C₃₀ - contain α-olefin-maleic anhydride copolymers and, to make up to 100% by weight, water. Although these liquid detergents initially represent clear solutions, they separate relatively quickly during storage.

From US Pat. No. 3,328,309, liquid alkaline detergent formulations are known which, in addition to water and detergents as stabilizers, contain 0.1 to 5%, based on the entire formulation, of a hydrolyzed copolymer of an α, β-unsaturated carboxylic anhydride with a vinyl ester, vinyl ether or contain an α-olefin in partially esterified form. Addition products of alkylene oxides, in particular ethylene oxide, onto alkylphenols are also suitable as alcohol components for the esterification. Only 0.01 to 5% of the carboxyl groups of the copolymer are present as ester groups. Although these liquid detergents contain components which are compatible with one another, ie they remain in solution without separating or clouding, the primary washing action of this liquid detergent formulation is still in need of improvement.

The present invention has for its object to provide polymers for the preparation of stable liquid detergent formulations which have an improved primary and secondary washing action compared to the liquid detergent formulations of the prior art. In the present context, stable liquid detergent formulation should be understood to mean the fact that the individual components of the formulation are compatible with one another and do not separate even after prolonged storage.

• (a) mindestens einem C₄- bis C₂₈-Olefin oder Mischungen aus mindestens einem C₄- bis C₂₈-Olefin mit bis zu 20 Mol% C₁- bis C₂₈-Alkylvinylethern und
• (b) ethylenisch ungesättigten Dicarbonsäureanhydriden mit 4 bis 8 C-Atomen

im Molverhältnis 1:1 zu Copolymerisaten mit K-Werten von 6 bis 100 (bestimmt nach H. Fikentscher in Tetrahydrofuran bei 25°C und einer Polymerkonzentration von 1 Gew.%) und anschließende partielle Veresterung der Copolymerisate mit umsetzungsprodukten von

• (A) C₁- bis C₃₀-Alkoholen, C₈- bis C₂₂-Fettsäuren, C₁- bis C₁₂-Alkyl­phenolen, sekundären C₂- bis C₃₀-Aminen oder deren Mischungen mit
• (B) mindestens einem C₂- bis C₄-Alkylenoxid oder Tetrahydrofuran

im Molverhältnis (A):(B) von 1:2 bis 50 und Hydrolyse der Anhydridgruppen der Copolymerisate zu Carboxylgruppen, wobei die partielle Veresterung der Copolymerisate so weit geführt wird, daß mehr als 5 bis 50 % der Carboxylgruppen der Copolymerisate verestert sind, oder von Salzen dieser partiell veresterten Copolymerisate,
als Zusatz zu Flüssigwaschmitteln in einer Menge von 0, 1 bis 20 Gew.%.The object is achieved according to the invention by using partially esterified copolymers which can be obtained by copolymerizing

• (a) at least one C₄ to C₂₈ olefin or mixtures of at least one C₄ to C₂₈ olefin with up to 20 mol% of C₁ to C₂₈ alkyl vinyl ethers and
• (b) ethylenically unsaturated dicarboxylic acid anhydrides with 4 to 8 carbon atoms

in a molar ratio of 1: 1 to copolymers with K values from 6 to 100 (determined according to H. Fikentscher in tetrahydrofuran at 25 ° C and a polymer concentration of 1% by weight) and subsequent partial esterification of the copolymers with reaction products of

• (A) C₁ to C₃₀ alcohols, C₈ to C₂₂ fatty acids, C₁ to C₁₂ alkylphenols, secondary C₂ to C₃₀ amines or mixtures thereof
• (B) at least one C₂ to C₄ alkylene oxide or tetrahydrofuran

in a molar ratio (A) :( B) of 1: 2 to 50 and hydrolysis of the anhydride groups of the copolymers to carboxyl groups, the partial esterification of the copolymers being carried out to such an extent that more than 5 to 50% of the carboxyl groups of the copolymers are esterified, or of salts of these partially esterified copolymers,
as an additive to liquid detergents in an amount of 0.1 to 20% by weight.

The liquid detergents which contain the partially esterified copolymers to be used according to the invention, when mixed with aqueous alkaline solutions of anionic and / or nonionic surfactants, give clear aqueous solutions which are stable on storage. These formulations have an increased primary and secondary washing action compared to comparable liquid detergents of the prior art.

• (a) mindestens ein C₄- bis C₂₈-Olefin oder Mischungen aus mindestens einem C₄- bis C₂₈-Olefin mit bis zu 20 Mol% C₁- bis C₄-Alkylvinylethern und
• (b) ethylenisch ungesättigten Dicarbonsäureanhydriden mit 4 bis 8 C-Atomen

im Molverhältnis 1:1 copolymerisiert. Als Komponente (a) kommen beispielsweise Isobutylen, Octen, Decen, Dodecen, Tetradecen, Hexadecen, Heptadecen, Octadecen und Mischungen der genannten Olefine in Betracht. Von den genannten Olefinen kommen nicht nur die Olefine mit endständiger Doppelbindung in Betracht, sondern auch Isomere. Vorzugsweise setzt man als Komponente (a) verzweigte C₆- bis C₁₈-Olefine oder deren Gemische ein. Besonders bevorzugt ist die Verwendung von Mischungen aus 2,4,4′-Trimethylpenten-1 und 2,4,4′-Trimethylpenten-2 als Komponente (a) der Copolymerisate.The partially esterified copolymers to be used according to the invention are prepared, for example, by first

• (a) at least one C₄ to C₂₈ olefin or mixtures of at least one C₄ to C₂₈ olefin with up to 20 mol% of C₁ to C₄ alkyl vinyl ethers and
• (b) ethylenically unsaturated dicarboxylic acid anhydrides with 4 to 8 carbon atoms

copolymerized in a molar ratio of 1: 1. Examples of possible components (a) are isobutylene, octene, decene, dodecene, tetradecene, hexadecene, heptadecene, octadecene and mixtures of the olefins mentioned. Of the olefins mentioned, not only the olefins with a terminal double bond can be considered, but also isomers. Preferably used as component (a) is a branched C₆ to C₁₈ olefins or mixtures thereof. The use of mixtures of 2,4,4'-trimethylpentene-1 and 2,4,4'-trimethylpentene-2 as component (a) of the copolymers is particularly preferred.

The isomeric trimethylpentenes mentioned can be used in any ratio in the copolymerization. Mixtures of these olefins which are used with particular preference comprise 35 to 45 mol% of 2,4,4'-trimethylpentene-1 and 5 to 15 mol% of 2,4,4'-trimethylpentene-2. Terpolymers which contain trimethylpentenes in copolymerized form with maleic anhydride are known, for example, from EP-PS 9 169 and EP-PS 9 170. Said olefins having 4 to 28 carbon atoms can optionally also be mixed with C₁ to C₂₈ alkyl vinyl ethers, e.g. Methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether or isobutyl vinyl ether can be copolymerized. The proportion of alkyl vinyl ethers in the mixture with at least one of the olefins in question is up to 20 mol%. For example, mixtures of 80 mol% diisobutylene and 20 mol% methyl vinyl ether can be used as component (a).

Monoethylenically unsaturated dicarboxylic anhydrides having 4 to 8 carbon atoms, for example maleic anhydride, itaconic anhydride, mesaconic anhydride, citraconic anhydride and methylene malonic anhydride, are suitable as component (b) for the preparation of the copolymers. Of the anhydrides mentioned, maleic anhydride and itaconic anhydride are preferably used, maleic anhydride being of particular importance in practice. The copolymerization of the monomers according to (a) and (b) produces alternating copolymers which contain the monomers mentioned in copolymerized form in a molar ratio of 1: 1. The K values of the copolymers are 6 to 100, preferably 8 to 40 (measured according to H. Fikentscher at 25 ° C. in tetrahydrofuran and a polymer concentration of 1% by weight). The copolymerization of the monomers (a) and (b) is carried out by known processes, for example in polar solvents which are inert to the acid anhydrides, such as acetone, tetrahydrofuran or dioxane as solution polymerization, in toluene, xylene or aliphatic hydrocarbons in the form of a precipitation polymerization or else by Bulk polymerization of components (a) and (b), it being advantageous to choose an excess of monomers of component (a) as the diluent. The polymerization is initiated in all processes with the aid of polymerization initiators. All compounds which break down into free radicals, for example peroxides, hydroperoxides, redox initiators and azo compounds, are suitable as polymerization initiators. The copolymers thus obtainable are then partially esterified and hydrolyzed, so that the anhydride groups are converted into carboxyl groups. It is also possible to first hydrolyze the copolymers containing anhydride groups so that all anhydride groups are present as carboxyl groups and then to carry out the esterification by known methods. However, a procedure is preferred in which the carboxylic anhydride groups of the copolymer are first partially esterified with the reaction products of (A) and (B).

Suitable compounds (A) are C₁ to C₃₀ alcohols, e.g. Methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, pentanol, cyclohexanol, n-hexanol, n-octanol, 2-ethylhexanol, decanol, dodecanol and stearyl alcohol. The alcohols produced by the oxo process, e.g. C₁₀ alcohols, C₁₃ alcohols and C₁₃ / C₁₅ alcohols or also natural alcohols, such as e.g. C₁₆ / C₁₈ tallow fatty alcohols. These alcohols and the native alcohols produced by the oxo process are generally mixtures of several alcohols.

Suitable compounds (A) are also C₈ to C₂₂ fatty acids, e.g. Stearic acid, palmitic acid, coconut fatty acid, tallow fatty acid, lauric acid and behenic acid. Component (A) also includes C₁ to C₁₂ alkylphenols, e.g. n-decylphenol, n-nonylphenol, isononylphenol, n-octylphenol, isobutylphenol and methylphenol. Secondary C₂ to C₃₀ amines are also used as component (A), e.g. Dimethylamine, di-n-butylamine, di-n-octylamine and di-stearylamine. Secondary C₈ to C₁₈ fatty amines are preferably used. C₁ to C₃ C alcohols or sec.-C₂ to C₁ sek amines are preferably used as component (A).

As component (B) are C₂ to C₄ alkylene oxides, such as ethylene oxide, propylene oxide, n-butylene oxide and isobutylene oxide. Also comes Tetrahydrofuran as component (B) into consideration. Compounds (B) which are preferably used are ethylene oxide and propylene oxide. Ethylene oxide and propylene oxide can either be added alone to the compounds indicated under (A) or in the form of a mixed gas with the formation of adducts containing random ethylene oxide and propylene oxide units, or else in such a way that ethylene oxide is initially added to the compounds mentioned under (A) and then adds propylene oxide or reverses the order, or first adds ethylene oxide, then propylene oxide and again ethylene oxide to the compounds (A), so that block copolymers are formed. Methods for the alkoxylation of the compounds (A) belong to the prior art.

The compounds (A) are reacted with the compounds (B) in a molar ratio of (A) to (B) from 1: 2 to 50, preferably 1: 3 to 12. This reaction produces reaction products in all cases in which at least one end group is an OH group. The reaction products of (A) and (B) thus produced are reacted with the copolymers of monomers (a) and (b) described above, partially esterified copolymers being formed. This reaction can be carried out in the presence of solvents which are inert to carboxylic anhydride groups, for example acetone or tetrahydrofuran, and is preferably carried out in bulk, ie the copolymers containing olefin-dicarboxylic anhydride groups are reacted directly with the reaction products of (A) and (B). The amounts are chosen so that only partial esterification of the anhydride groups occurs. Based on the hydrolyzed partially esterified polymer, more than 5, for example 5.5 to 50, preferably 9 to 30% of the carboxyl groups are esterified. The esterification itself is generally carried out at higher temperatures, for example 50 to 200, preferably 80 to 150 ° C. in the presence of customary esterification catalysts. P-Toluenesulfonic acid is particularly suitable as a catalyst. The esterification reaction is complete after about 0.5 to 20, preferably 1 to 10 hours. Solvents for the esterification reaction, if they are used at all, are all those organic liquids which are inert to the anhydride groups and which dissolve or swell both the starting materials and the partially esterified copolymers, for example toluene, xylene, ethylene benzene, aliphatic hydrocarbons and ketones, such as acetone and methyl ketone. After the partial esterification, the solvents - if they are used - are removed from the reaction mixture, for example by distillation, and the remaining partially esterified copolymers are dissolved in water with the addition of alkalis. The anhydride groups still present in copolymers are hydrolyzed here. Suitable alkalis are, for example, sodium hydroxide solution, potassium hydroxide solution, ammonia, amines and alkanolamines. The pH of the aqueous partially esterified copolymer solutions thus obtained is 4 to 10 and is preferably in the range of 6 to 8.

The partially esterified copolymers to be used according to the invention are also obtainable, for example, by mono- and diesters derived from C₁ to C₃ alcohols, the monoethylenically unsaturated dicarboxylic acids (component (b)) with the reaction products of (A) described above and (B) partially transesterified and the transesterified products then copolymerized with at least one C₄ to C₂₈ olefin or mixtures of at least one C₄ to C₂₈ olefin with up to 20 mol% of C₁ to C₄ alkyl vinyl ethers. The reaction of the mono- and diesters of the monoethylenically unsaturated dicarboxylic acids with the reaction products from (A) and (B) is only carried out to an extent which is at least 5 to 50% of the ester groups which are derived from a C₁ to C₃ alcohol , react. After the copolymerization, the reaction takes place with alkali, ammonia and / or alkanolamines to give the water-soluble salts, at least some hydrolysis of the starting mono- or diesters of C₁ to C₃ alcohols occurring. However, partial esterification of alternating copolymers from (a) and (b) containing anhydride groups with the reaction products of (A) and (B) is preferred in any case.

• (a) mindestens einem C₄- bis C₂₈-Olefin oder Mischungen aus mindestens einem C₄- bis C₂₈-Olefin mit bis zu 20 Mol% C₁- bis C₂₈-Alkylvinyl­ethern und
• (b) den Reaktionsprodukten aus (b1) ethylenisch ungesättigten Dicarbon­säureanhydriden mit 4 bis 8 C-Atomen und (b2) den Umsetzungsprodukten aus
  
• (A) C₁- bis C₃₀-Alkoholen, C₈- bis C₂₂-Fettsäuren, C₁- bis C₁₂-Alkylphenolen oder sekundären C₂- bis C₃₀-Aminen mit
  
• (B) mindestens einem C₂- bis C₄-Alkylenoxid oder Tetrahydrofuran
  im Molverhältnis (A):(B) von 1:2 bis 50, so daß mehr als 5 bis 50 % der Anhydridgruppen verestert sind,

im Molverhältnis (a):(b) von 1:1 zu Copolymerisaten mit K-Werten von 6 bis 100 und Hydrolyse der nicht umgesetzten Anhydridgruppen der Copolymerisate zu Carboxylgruppen oder deren Salze.The copolymers to be used according to the invention can also be obtained by copolymerizing

• (a) at least one C₄ to C₂₈ olefin or mixtures of at least one C₄ to C₂₈ olefin with up to 20 mol% of C₁ to C₂₈ alkyl vinyl ethers and
• (b) the reaction products from (b1) ethylenically unsaturated dicarboxylic acid anhydrides having 4 to 8 carbon atoms and (b2) the reaction products
  
• (A) C₁ to C₃₀ alcohols, C₈ to C₂₂ fatty acids, C₁ to C₁₂ alkylphenols or secondary C₂ to C₃₀ amines with
  
• (B) at least one C₂ to C₄ alkylene oxide or tetrahydrofuran
  in the molar ratio (A) :( B) from 1: 2 to 50, so that more than 5 to 50% of the anhydride groups are esterified,

in the molar ratio (a) :( b) of 1: 1 to copolymers with K values from 6 to 100 and hydrolysis of the unreacted anhydride groups of the copolymers to carboxyl groups or their salts.

The partially esterified copolymers to be used according to the invention can be in the form of the free acids and in partially or completely neutralized form and can be added to liquid detergents in each of these forms. The liquid detergent formulations, which contain the partially esterified copolymers described above in an amount of 0.1 to 20, preferably 1 to 10% by weight, are usually made alkaline and have, as a further essential constituent, at least one anionic surfactant, a nonionic surfactant or their mixtures and water. These are clear aqueous solutions. Suitable anionic surfactants are, for example, sodium alkylbenzenesulfonates, fatty alcohol sulfates and fatty alcohol polyglycol ether sulfates. Individual compounds of this type are, for example, C₈ to C₁₂ alkyl benzene sulfonates, C₁₂ to C₁- alkane sulfonates, C₁₂ to C₁₆ alkyl sulfates, C₁₂ to C₁₆ alkyl sulfosuccinates and sulfated ethoxylated C₁₂ to C₁₆ alkanols. Also suitable as anionic surfactants are sulfated fatty acid alkanolamines, fatty acid monoglycerides or reaction products of 1 to 4 moles of ethylene oxide with primary or secondary fatty alcohols or alkylphenols. Further suitable anionic surfactants are fatty acid esters or fatty acid amides of hydroxy or aminocarboxylic acids or sulfonic acids, such as, for example, the fatty acid sarcosides, glycolates, lactates, taurides or isothionates. The anionic surfactants can be in the form of the sodium, potassium and ammonium salts and also as soluble salts of organic bases, such as mono-, di- or triethanolamine or other substituted amines. The anionic surfactants also include the usual soaps, i.e. the alkali salts of natural fatty acids.

Addition products of 3 to 40, preferably 4 to 20 moles of ethylene oxide with 1 mole of fatty alcohol, alkylphenol, fatty acid, fatty amine, fatty acid amide or alkanesulfonamide can be used, for example, as nonionic surfactants (nonionics). The addition products of 5 to 16 moles of ethylene oxide with coconut oil or tallow fatty alcohols, with oleyl alcohol or with synthetic alcohols with 8 to 18, preferably 12 to 18 carbon atoms, and with mono- or dialkylphenols with 6 to 14 carbon atoms in are particularly important the alkyl residues. In addition to these water-soluble nonionics, non-fully or not fully water-soluble polyglycol ethers with 1 to 4 ethylene glycol ether residues in the molecule are also of interest, in particular if they are used together with water-soluble nonionic or anionic surfactants.

Furthermore, the non-ionic surfactants that can be used are the water-soluble adducts of ethylene oxide with 20 to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups with polypropylene glycol ethers, alkylene diaminopolypropylene glycol and alkyl polypropylene glycols with 1 to 10 carbon atoms in the alkyl chain, in which the polypropylene glycol ether chain functions as a hydrophobic residue.

Nonionic surfactants of the amine oxide or sulfoxide type can also be used.

The foaming power of the surfactants can be increased or decreased by combining suitable types of surfactants. A reduction can also be achieved by adding non-surfactant-like organic substances.

The liquid, aqueous detergents contain 10 to 50% by weight of surfactants. You can contain an anionic or nonionic surfactant in the amount specified. However, it is also possible to use mixtures of anionic and nonionic surfactants. In such a case, the content of anionic surfactants in the liquid detergent is chosen from 10 to 30% by weight and the content of nonionic surfactants in the liquid detergent from 5 to 20% by weight, based on the total detergent formulation.

As an essential component, the liquid detergents contain the partially esterified copolymers to be used according to the invention in amounts of 0.1 to 20, preferably 1 to 10% by weight and water in amounts of 10 to 60, preferably 20 to 50% by weight.

The liquid detergents may also contain other substances for modification. These include, for example, alcohols, such as ethanol, n-propanol and isopropanol. If used, these substances are used in amounts of 3 to 8% by weight, based on the total detergent formulation. The liquid detergents may also contain hydrotropes. This includes compounds such as 1,2-propanediol, cumene sulfonate and toluene sulfonate. If such compounds are used to modify the liquid detergent, their amount, based on the total weight of the liquid detergent, is 2 to 5% by weight. In many cases, addition of complexing agents has also proven to be advantageous for modification. Complexing agents are, for example, ethylenediaminetetraacetic acid, nitrilotriacetate and isoserinediacetic acid. The complexing agents are used in amounts of 0 to 10% by weight, based on the liquid detergent. The liquid detergents can also contain citrates, di- or Contain triethanolamine, opacifiers, optical brighteners, enzymes, perfume oils and dyes. If these substances are used to modify the liquid detergents, they are present in quantities of up to 5% by weight. The liquid detergents according to the invention are preferably phosphate-free. However, they can also contain phosphates, for example pentasodium triphosphate and / or tetrapotassium pyrophosphate. If phosphates are used, the proportion of phosphates in the total formulation of the liquid detergent is 10 to 25% by weight.

The liquid detergents described above have the advantage over the powder detergents that they are easy to dose and have very good fat and oil dissolving power at greasy soiled laundry at lower washing temperatures. Liquid detergents contain high levels of detergent substances, which remove dirt from the textile fabric at washing temperatures of 40 to 60 ° C. The dispersing properties of polymers have hitherto not been able to be used in aqueous liquid detergents because, as a result of high electrolyte concentrations in the detergents, it was not possible to obtain stable solutions with the polymers. With the partially esterified copolymers to be used according to the invention, it is now possible to produce stable aqueous solutions of liquid detergents and to significantly improve the washing properties of liquid detergents. The effectiveness of the partially esterified copolymers to be used according to the invention in liquid detergents is demonstrated in the examples with the aid of the stability of the liquid detergents and the primary and secondary washing action of these detergents. The primary washing effect is the actual removal of dirt from the textile material. The degree of dirt removal is the difference in the degree of whiteness between the unwashed and the washed textile material after washing. Cotton, cotton / polyester and polyester fabrics with standard soiling are used as the textile test material. After each wash, the whiteness of the fabric in% remission is determined in an Zeiss elrephophotometer.

Secondary washing is understood to mean the effects which arise from the re-accumulation of the dirt detached from the fabric on the fabric in the wash liquor. The secondary washing effect can only become visible after several washes, for example 3, 5, 10 or even only 20 washes, which is noticeable in increasing graying (redeposition), that is, dirt from the washing liquor accumulates on the fabric. To determine the tendency to graying, standard soiling fabric is washed several times together with white test fabric and the soiled fabric is renewed after each wash. The dirt detached from the dirt fabric, which is drawn onto the white test fabric during washing, causes one Decrease in whiteness that is measured. The partially esterified copolymers or their water-soluble salts to be used in liquid detergents according to the invention can also be used for the formulation of powder detergents.

The percentages in the examples are percentages by weight. The K values were determined according to H. Fikentscher, Cellulose Chemie, Vol. 13, 58 to 64 and 71 to 74 (1932). The K values of the copolymers containing anhydride groups were determined in tetrahydrofuran at a temperature of 25 ° C. and a polymer concentration of 1% by weight. The K values of the hydrolyzed copolymers were measured in aqueous solution at 25.degree. C., a pH of 7.5 and a polymer concentration of 1% by weight.

Preparation of the partially esterified copolymers to be used according to the invention Copolymer 1

550 g of n-dodecene and 98 g of maleic anhydride are placed in a polymerization reactor provided with a stirrer, thermometer, cooler, nitrogen inlet and nitrogen outlet and metering devices and heated to a temperature of 100 ° C. in a gentle stream of nitrogen. As soon as the temperature of 100 ° C. is reached, a solution of 5 g of tert-butylethylhexanoate in 34 g of dodecene is added within 3 hours and the reaction mixture is heated to a temperature of 100 ° C. 2 hours after the initiator has been added. A clear solution of a copolymer in dodecene is obtained. The unreacted dodecene is distilled off under reduced pressure. 266 g of a copolymer of n-dodecene and maleic anhydride having a K value of 10.7 are obtained.

266 g of the product obtained in the copolymerization are reacted with 104.4 g of the adduct of 7 moles of ethylene oxide with 1 mole of a C₁₃ / C₁₅ oxo alcohol in the presence of 0.275 g of a p-toluenesulfonic acid within 4 hours at 150 ° C. The reaction mixture is then cooled to a temperature of 100 ° C. and processed into an aqueous solution by simultaneously adding 250 g of water and 83 g of 50% strength aqueous potassium hydroxide solution. After adding the water and the potassium hydroxide solution, the reaction mixture is stirred at 55 to 60 ° C for 2 hours. The result is a light brown viscous solution with a solids content of 56.2%. The pH of this solution is 7.3. The K value of the dissolved copolymer is 27.9. 10% of the carboxyl groups were esterified in the reaction.

Copolymer 2

980 g of maleic anhydride, 1440 g of xylene and 14 g of polyvinylethyl ether having a K value of 50 (determined on 1% strength solutions in cyclohexanone) are initially introduced into the polymerization reactor described above, which is also designed for working under elevated pressure. The reactor is then tightly sealed and pressurized with 10 bar of nitrogen. Immediately afterwards, the reactor is let down. The nitrogen injection is repeated two more times. The reactor contents are then heated to a temperature of 140 ° C. and 600 g of isobutene are metered in within 3 hours and a solution of 46 g of tert-butyl perethylhexanoate and 31 g of di-tert is added within 4 hours after the temperature has reached 140 ° C. -butyl peroxide in 100 g of xylene and the reaction mixture is heated at 140 ° C. for 1 hour after the addition of the initiator has ended. A maximum pressure of 8 bar was established during the reaction. After the completion of the reaction, the reaction mixture is carefully let down and the xylene used as solvent is distilled off. The 150 ° C hot melt is then emptied onto a metal sheet on which it solidifies to form a brown, brittle resin with a K value of 9.7.

308 g of the copolymer of isobutene and maleic anhydride thus prepared are then with 208.8 g of the reaction product of 7 moles of ethylene oxide with one mole of a C₁₃ / C₁₅ oxo alcohol in the presence of 0.31 g of p-toluenesulfonic acid at 150 ° C within 4 hours partially esterified with stirring. The reaction mixture is then cooled to 100 ° C. and dissolved by adding 375 g of water and 185 g of a 50% strength aqueous potassium hydroxide solution and then stirring at 50 to 60 ° C. for 2 hours. A brown viscous solution with a solids content of 43.8% is formed. The pH of this solution is 7.1. The K value of the partially esterified copolymer is 28.9. 10% of the carboxyl groups were esterified.

Copolymer 3

In the reactor described in Example 1, 1507.3 g of diisobutene (isomer mixture of 80% trimethylpentene-1 and 20% trimethylpentene-2), 630 g of maleic anhydride and 5.4 g of polyvinyl ethyl ether with a K value of 50 (measured in a 1% strength solution) in cyclohexanone) and heated to boiling. Half of a solution of 30 g of tert-butyl perethylhexanoate in 100 parts of diisobutene is added within 2 hours and the other half of this solution is then metered in over the course of 1 hour. After the initiator has been added, the reaction mixture is heated to boiling for a further 2 hours. The fine-grained suspension of the copolymer is then filtered off and dried in a rotary evaporator at 60 ° C. under a Pressure of 20 mbar. 1350 g of a fine white powder are obtained, which has a K value of 36.

420 g of copolymerized maleic anhydride thus prepared copolymers are reacted with 159.6 g of an adduct which can be obtained by reacting 5 moles of propylene oxide and then 2.5 moles of ethylene oxide with one mole of a C₁₃ / C₁₅ oxo alcohol. In the partial esterification, 0.42 g of p-toluenesulfonic acid is used as the catalyst and 362 g of toluene are used as the diluent. This reaction mixture is refluxed for 12 hours. The toluene is then distilled off and 320 g of a light yellow, brittle resin are obtained, which is dissolved in a solution of 152 g of potassium hydroxide solution in 300 g of water at 80.degree. After the partially esterified copolymer has completely dissolved, there is a highly viscous solution which is diluted by adding water to such an extent that it can be easily stirred. The clear, slightly yellowish solution thus obtained has a solids content of 27.6% and a pH of 7.1. The K value of the partially esterified copolymer is 47.5. 6.5% of the carboxyl groups of the hydrolyzed copolymer were esterified.

Copolymers 4 to 13

In the reactor specified in Example 1, which is operated under excess pressure, 1082 g of diisobutylene (isomer mixture of 80% trimethylpentene-1 and 20% trimethylpentene-2) and 49 g of maleic anhydride are introduced. The reactor is then closed tightly and injected with 6 bar of nitrogen. The reactor is then depressurized and pressed twice more in the white described with 6 bar of nitrogen. The contents of the reactor are then heated to 160 ° C. with stirring. 931 g of maleic anhydride are then metered in over the course of 2 hours, and a solution of 63 g of di-tert-butyl peroxide in 150 g of diisobutene is added over the course of 3 hours. After the addition of initiator has ended, the reaction mixture is stirred at 160 ° C. for a further hour. Then 246 g of unpolymerized diisobutene are distilled off under a pressure of 100 mbar. The clear, golden-yellow melt obtainable in this way is emptied onto a metal sheet and, after cooling to room temperature, is present as a brittle resin which has a K value of 12.6. 420 g of this resin are then mixed with the amounts of alkoxylated compounds given in Table 1, which can be obtained by reacting (A) with the alkylene oxides (B), in the presence of 0.8 g of p-toluenesulfonic acid within 4 hours at 150 ° C implemented. The anhydride groups of the partially esterified copolymer are then hydrolyzed and the free acid groups are neutralized by dissolving the reaction product in the amounts of KOH and water indicated in Table 1. in all cases there are clear aqueous solutions of the potassium salts of the partially esterified copolymers. Table 1 Copolymer Proportion of COOH groups converted to esters [%] Alkoxylated amount [g] Compound obtainable by alkoxylation of 1 mol (A) with ... mol (B) H₂O [g] KOH 50% [g] Solids content of the aqueous solution PH value K value of the final product 4th 10th 173.6 C₁₃ / C₁₅ oxo alcohol 5 EO ¹⁾ 380 211 43.8 7.1 15.3 5 10th 208.8 C₁₃ / C₁₅ oxo alcohol 7 EO 420 218 49.3 7.2 14.8 6 10th 261.6 C₁₃ / C₁₅ oxo alcohol 10 EO 420 232 54.4 7.2 14.3 7 12.5 261 C₁₃ / C₁₅ oxo alcohol 7 EO 300 205 62.2 7.2 14.3 8th 25th 522 C₁₃ / C₁₅ oxo alcohol 7 EO 400 149 59.4 7.6 15.0 9 10.3 228 C₁₃ oxo alcohol 8 EO 400 223 50.2 7.0 13.8 10th 32.5 611 C₁₀ oxo alcohol 7 EO 800 170 52.5 7.0 12.8 11 10th 314.8 Fatty amine 12 EO 450 178 40.7 8.4 11.7 12 10th 276.8 Methanol 15 EO 430 178 49.0 7.0 12.6 13 10th 220 C₁₂ / C₁₄ oxo alcohol 8 EO 400 213 53.1 7.1 13.7 ¹⁾ EO = ethylene oxide

Example 14

In a reactor according to Example 1, which can be operated under excess pressure, 196 g of maleic anhydride, 0.42 g of p-toluenesulfonic acid and 228 g of a reaction product of a C₁₃ oxo alcohol with 8 moles of ethylene oxide are heated to 150 ° C. After 4 hours at 150 ° C., the reactor is tightly sealed, pressed three times with 6 bar of nitrogen and 224 g of diisobutene (isomer mixture of 80% trimethylpentene-1 and 20% trimethylpentene-2) are pumped in, a pressure of 8 bar being established. A solution of 12.5 g of di-tert-butyl peroxide in 50 g of diisobutene is then metered in within 4 hours and the mixture is then heated at 150 ° C. for 1 hour. The pressure is then carefully released and then the last traces of unreacted diisobutene are distilled off under vacuum. It is then cooled to 90 ° C. and 400 g of water and 222 g of 50% strength aqueous potassium hydroxide solution are metered in over the course of 0.5 hours and the mixture is reheated at 60 ° C. for 2 hours. The yellow solution obtained has a solids content of 54.3%. The K value of the end product is 15.9.

Application engineering examples

Copolymers 1 to 14 described above were tested in the following liquid detergent formulation:

Liquid detergent formulation

20% of the reaction product from 1 mole of C₁₃ / C₁₅ oxo alcohol and 7 moles of ethylene oxide
10% sodium dodecylbenzenesulfonate, 50% in water
10% coconut fatty acid
5% triethanolamine
6% copolymer (calc. 100%)
Rest on 100 water

For comparison with the prior art, a copolymer-free detergent formulation and a detergent formulation which contained 6% of a copolymer of maleic anhydride and diisobutene with a K value of 12.6 as the potassium salt were tested.

The primary washing effect was determined under the following washing conditions: Dirt removal, whiteness -% remission Washing machine Launder-O-meter Washing temperature 60 ° C Water hardness 3 mmol Ca²⁺ / = 16.8 ° d Ca: Mg ratio 3: 2 Washing time 30 minutes Wash cycles 1 Detergent dosage 6 g detergent per liter Fleet ratio 1:25 tissue WFK ¹) 20 D (polyester / cotton) EMPA ²) 104 (polyester / cotton) Whiteness measurement in Elrepho in% remission Whiteness of unwashed fabrics: WFK 20 D 40.5 EMPA 104 13 ¹) WFK = laundry research Krefeld ²) EMPA = Federal Materials Testing Office, St. Gallen, Switzerland The secondary washing effect, which is a measure of the graying of the fabric, was determined as follows: Washing machine Launder-O-meter Washing temperature 60 ° C Water hardness 3 mmol Ca²⁺ / = 18, ° d Ca: Mg ratio 3: 2 Washing time 30 minutes Wash cycles 1 Detergent dosage 6 g detergent per liter Fleet ratio 1:14 tissue Cotton / polyester fabric Polyester fabric WFK dirt fabric (is renewed after every wash) Whiteness measurement in Elrepho in% remission Whiteness of unwashed fabrics: Cotton polyester 72 polyester 74 The stability of the liquid detergent formulations produced in each case and the primary wash action and secondary wash action which can be achieved with these formulations are given in Table 2. Table 2 Stability, primary and secondary washing action of the detergent formulations Example No. Copolymer Stability at room temperature (23 ° C) after Primary washing effect -% remission Secondary wash effect -% remission 1 day 1 week 4 weeks WFK 20 D fabric EMPA 104 fabric Cotton polyester polyester 1 1 + + + 56.0 25.0 68.5 45.0 2nd 2nd + + + 54.5 25.6 67.5 45.5 3rd 3rd + + + 56.5 26.0 65.0 46.0 4th 4th + + + 56.5 26.5 68.5 45.0 5 5 + + + 56.0 27.5 70.0 45.5 6 6 + + + 54.0 24.5 62.0 44.0 7 7 + + + 57.0 27.0 71.0 50.0 8th 8th + + + 56.5 26.5 69.5 47.0 9 9 + + + 55.8 25.5 69.0 46.0 10th 10th + + + 54.5 24.7 63.0 44.5 11 11 + + + 55.0 25.0 60.0 45.0 12 12 + + + 57.0 25.4 67.0 44.5 13 13 + + + 57.0 26.5 66.0 45.0 14 14 + + + 53.5 24.5 63.0 44.0 Cf. Example No. 1 without + + + 46.0 23.0 55.0 43.0 Cf. Example No. 2 Copo from MSA / DIB - - - 52.0 23.5 60.0 43.5 + = stable - = unstable Example 2 is a copolymer of maleic anhydride and diisobutene with a K value of 12.6 as the potassium salt

As clearly shown in Table 2, when using the partially esterified copolymers to be used according to the invention, liquid detergents are obtained which are stable in storage and which have an improved primary washing action and secondary washing action compared to a hydrolyzed, non-esterified copolymer made from maleic anhydride and diisobutene.

Claims (6)

1. Use of partially esterified copolymers which are obtainable by copolymerizing
(a) at least one C₄ to C₂₈ olefin or mixtures of at least one C₄ to C₂₈ olefin with up to 20 mol% of C₁ to C₂₈ alkyl vinyl ethers and
(b) ethylenically unsaturated dicarboxylic acid anhydrides with 4 to 8 carbon atoms
in a 1: 1 molar ratio to copolymers with K values from 6 to 100 (determined according to H. Fikentscher in tetrahydrofuran at 25 ° C. and a polymer concentration of 1% by weight) and subsequent partial esterification of the copolymers with reaction products of
(A) C₁ to C₃₀ alcohols, C₈ to C₂₂ fatty acids, C₁ to C₁₂ alkylphenols, secondary C₂ to C₃₀ amines or mixtures thereof
(B) at least one C₂ to C₄ alkylene oxide or tetrahydrofuran
in a molar ratio (A) :( B) of 1: 2 to 50 and hydrolysis of the anhydride groups of the copolymers to carboxyl groups, the partial esterification of the copolymers being carried out to such an extent that more than 5 to 50% of the carboxyl groups of the copolymers are esterified, or of salts of these partially esterified copolymers,
as an additive to liquid detergents in an amount of 0.1 to 20% by weight. 2. Use according to claim 1, characterized in that initially for the preparation of the partially esterified copolymers
(A) branched C₆ to C₁₈ olefins or mixtures thereof and
(b) Maleic anhydride or itaconic anhydride are copolymerized and then the copolymers thus prepared with reaction products of
(A) C₁ to C₃₀ alcohols, C₈ to C₁₈ fatty acids, C₁ to C₁₂ alkylphenols or secondary C₂ to C₃₀ amines
(B) ethylene oxide and / or propylene oxide
are partially esterified in a molar ratio (A) :( B) of 1: 2 to 50, the partial esterification of the copolymers being carried out to such an extent that 9 to 30% of the carboxyl groups of the copolymers are esterified. 3. Use according to claim 1 or 2, characterized in that for the preparation of the partially esterified copolymers as a component
(a) Mixtures of 2,4,4'-trimethylpentene-1 and 2,4,4'-trimethylpentene-2 and as a component
(b) Maleic anhydride
be used. 4. Use according to one of claims 1 to 3, characterized in that for the preparation of the partially esterified copolymers, the partial esterification with reaction products of
(A) C₁ to C₃₀ alcohols or secondary C₂ to C₃₀ amines
(B) ethylene oxide or ethylene oxide and propylene oxide
is made. 5. Use according to claim 1, characterized in that the partially esterified copolymers are obtainable by copolymerizing
(a) at least one C₄ to C₂₈ olefin or mixtures of at least one C₄ to C₂₈ olefin with up to 20 mol% of C₁ to C₂₈ alkyl vinyl ethers and
(b) the reaction products from (b1) ethylenically unsaturated dicarboxylic acid anhydrides having 4 to 8 carbon atoms and (b2) the reaction products
(A) C₁ to C₃₀ alcohols, C₈ to C₂₂ fatty acids, C₁ to C₁₂ alkylphenols or secondary C₂ to C₃₀ amines with
(B) at least one C₂ to C₄ alkylene oxide or tetrahydrofuran
in the molar ratio (A) :( B) from 1: 2 to 50, so that more than 5 to 50% of the anhydride groups are esterified,
in the molar ratio (a) :( b) of 1: 1 to copolymers with K values from 6 to 100 and hydrolysis of the unreacted anhydride groups of the copolymers to carboxyl groups or their salts. 6. Liquid, alkaline detergent formulations that are essential ingredients
(1) at least one anionic surfactant, a nonionic surfactant or mixtures thereof,
(2) partially esterified copolymers and
(3) water
Contain, characterized in that they contain partially esterified copolymers as an ingredient (2) in an amount of 0.1 to 20 wt.%, And that these copolymers can be prepared by copolymerizing
(a) at least one C₄ to C₂₈ olefin or mixtures of at least one C₄ to C₂₈ olefin with up to 20 mol% of C₁ to C₄ alkyl vinyl ethers and
(b) ethylenically unsaturated dicarboxylic acid anhydrides with 4 to 8 carbon atoms
in a 1: 1 molar ratio to copolymers with K values from 6 to 100 (determined according to H. Fikentscher in tetrahydrofuran at 25 ° C. and a polymer concentration of 1% by weight) and subsequent partial esterification of the copolymers with reaction products of
(A) C₁ to C₃₀ alcohols, C₈ to C₂₂ fatty acids, C₁ to C₁₂ alkylphenols, secondary C₂ to C₃₀ amines or mixtures thereof
(B) at least one C₂ to C₄ alkylene oxide or tetrahydrofuran
in a molar ratio (A) :( 8) of 1: 2 to 50 and hydrolysis of the anhydride groups of the copolymers to carboxyl groups, the partial esterification of the copolymers being carried out to such an extent that more than 5 to 50% of the carboxyl groups of the copolymers are esterified.