EP0622449B1 - Water-softening compositions - Google Patents

Abstract

The invention relates to the use of water-softening compositions which contain (a) biodegradable copolymers, (b) inorganic water-softening silicates and, where appropriate, (c) further inorganic salts, (d) dispersants and complexing agents and (e) surfactants as well as other customary additives. These compositions are distinguished by better biodegradability.

Description

The invention relates to water-softening formulations improved biodegradability.

The function of a water softener is that of the Water-derived calcium and magnesium ions by complexation, Dispersion and sequestration from the washing process too eliminate and thereby support the washing effect of the surfactants. The softener reduces the formation of deposits in the washing machine, e.g. on the heating elements.

There are usually water softeners according to J. Falbe, surfactants in Consumer Products, 1987, 292-293, predominantly from Phosphates or from mixtures of phosphates, zeolites and Polycarboxylates. Although both types of softeners bind well for alkaline earth ions and an excellent dispersing and have dirt-bearing capacity, they are ecological Disadvantages. So the pollution of the wastewater with phosphates over-fertilization of the waters and those with eutrophication related problems. As substitutes for phosphates Combinations of zeolites and polycarboxylates are common used. For example, DE-A-39 31 871 is phosphate-free Water softeners are described that are predominantly made up Zeolite, layered silicate and sodium salt of a polycarboxylic acid, preferably an acrylic acid-maleic acid copolymer.

EP 0 404 377 A1 also describes water-soluble copolymers from maleic anhydride and (meth) acrylic acid or their corresponding ammonium and / or alkali salts by oxidative Cleavage of high molecular weight polymers in aqueous solution can be obtained with strong oxidizing agents, the copolymers in detergents or as a means of preventing Scale or precipitation should be used.

EP 0 425 068 A2 and EP 0 391 711 A2 relate to copolymers or optionally terpolymers of maleic anhydride and vinyl acetate, by copolymerization in a non-aqueous medium be obtained and also to prevent scale formation or similar deposits.

EP 0 497 611 A1 describes the production or use of partially biodegradable terpolymers in detergent formulations or water treatment agents from unsaturated Monocarboxylic acids, dicarboxylic anhydride and vinyl acetate, which polymerized in organic solvents and then be hydrolyzed by water, the non-aqueous Polymerization obtained copolymers or terpolymers hydrolyzed Have groups of less than 1 mole%.

Disadvantage of the polycarboxylates used today is that the polymers have a low biological Have degradability and therefore only a small part in the Wastewater treatment plant to be mineralized.

There was therefore the task of water softening formulations to provide the environmental disadvantages mentioned do not have.

(a) 5 bis 80 Gew.-% biologisch abbaubare Copolymere, die einen Abbaugrad von ≥ 60% aufweisen und erhältlich sind durch radikalische Polymerisation von

A. monoethylenisch ungesättigten Dicarbonsäuren und/oder deren Salzen,

B. monoethylenisch ungesättigten Monocarbonsäuren und/oder deren Salzen,

C. einfach ungesättigten Monomeren, die nach Polymerisation und Hydrolyse oder Verseifung Monomereinheiten ergeben, die eine oder mehrere Hydroxylgruppen an der Kohlenstoffkette aufweisen, und

D. 0 bis 15 Gew.-% weiteren, radikalisch copolymerisierbaren Monomeren, in wässrigem Medium und anschließender Hydrolyse oder Verseifung der polymerisierten Monomereinheiten nach C,

(b) 10 bis 95 Gew.-% wasserenthärtende anorganische Silikate,

(c) 0 bis 80 Gew.-% weitere anorganische Salze,

(d) 0 bis 70 Gew.-% Dispergier- und Komplexierungsmittel und

(e) 0 bis 5 Gew.-% Tenside

enthalten.According to the invention, the object is achieved by water-softening formulations which, based on the anhydrous substance,

(a) 5 to 80% by weight of biodegradable copolymers which have a degree of degradation of ≥ 60% and are obtainable by radical polymerization of

A. monoethylenically unsaturated dicarboxylic acids and / or their salts,

B. monoethylenically unsaturated monocarboxylic acids and / or their salts,

C. monounsaturated monomers which, after polymerization and hydrolysis or saponification, give monomer units which have one or more hydroxyl groups on the carbon chain, and

D. 0 to 15% by weight of further free-radically copolymerizable monomers, in an aqueous medium and subsequent hydrolysis or saponification of the polymerized monomer units according to C,

(b) 10 to 95% by weight of water-softening inorganic silicates,

(c) 0 to 80% by weight of further inorganic salts,

(d) 0 to 70% by weight of dispersing and complexing agents and

(e) 0 to 5 wt% surfactants

contain.

Formulations which are particularly preferred contain the Copolymers as component (a) in proportions of 5 to 30% by weight.

Monomers of group A are monoethylenically unsaturated C ₄ -C ₈ dicarboxylic acids, their anhydrides or their alkali and / or ammonium salts and / or amine salts. Suitable dicarboxylic acids are, for example, maleic acid, fumaric acid, itaconic acid and methylene malonic acid. Maleic acid, maleic anhydride, itaconic acid, itaconic anhydride and the corresponding sodium, potassium or ammonium salts of maleic or itaconic acid are preferably used. The group A monomers are preferably present in the monomer mixture in an amount of 10 to 70% by weight, more preferably 20 to 60% by weight and very particularly preferably 25 to 55% by weight.

Suitable group B monomers are monoethylenically unsaturated C ₃ -C ₁₀ -monocarboxylic acids and their alkali and / or ammonium salts and / or amine salts. These monomers include, for example, acrylic acid, methacrylic acid, dimethyl acid, ethyl acrylic acid, vinyl acetic acid and allylacetic acid. From this group of monomers, preference is given to using acrylic acid, methacrylic acid, their mixtures and the sodium, potassium or ammonium salts or mixtures thereof. The group B monomers are preferably present in the monomer mixture in an amount of 20 to 85% by weight, more preferably 25 to 60% by weight and very particularly preferably 30 to 60% by weight.

The group C monomers include those after the copolymerization and a subsequent hydrolysis or saponification of the polymer one or more hydroxyl groups directly on the C-C polymer carbon chain are covalently bound, release. Be exemplary called: vinyl acetate, vinyl propionate, methyl vinyl acetate, Methyl vinyl ether, ethylene glycol monovinyl ether and vinylidene carbonate. The Group C monomers are preferably 1 to 50% by weight, particularly preferably 4 to 40% by weight and very particularly preferably 8 to 30% by weight present in the monomer mixture.

As group D monomers used to modify the copolymers can be z. B. sulfone groups and sulfate groups containing monomers, such as meth (allylsulfonic acid), vinylsulfonic acid, Styrene sulfonic acid, acrylamidomethyl propane sulfonic acid and Monomers containing phosphonic acid groups, such as vinylphosphonic acid, Allylphosphonic acid and acrylamidomethylpropanephosphonic acid and their salts and hydroxyethyl (meth) acrylate sulfates, allyl alcohol sulfates and phosphates. Group D monomers may also be used because of the required solubility, however, only in a limited amount - twice ethylenically unsaturated non-conjugated compounds and polyalkylene glycol esters of (meth) acrylic acid and polyalkylene glycol ether with (Meth) allyl alcohol, which may or may not be end-capped, is used become. The group D monomers are optionally up to 15 % By weight, preferably up to 10% by weight, is present in the monomer mixture.

The copolymers are obtained by radical polymerization in an aqueous medium manufactured. Such a polymerization is, for example described in German patent application 43 00 772, published on 7/21/94.

This is followed by monoethylenically unsaturated dicarboxylic acids and / or their salts and / or dicarboxylic acid anhydrides, monoethylenic unsaturated monomers after hydrolysis or Saponification to form monomer units with one or more at the C-C chain covalently bonded hydroxyl groups are converted can and optionally other radically copolymerizable Contain monomers in aqueous solution at 40 to 180 ° C in Radically polymerized presence of polymerization initiators with subsequent hydrolysis and saponification, likewise in an aqueous medium. As polymerization initiators Compounds used under the polymerization conditions Form radicals, e.g. B. inorganic and organic peroxides, Persulfates, azo compounds and so-called redox catalysts. The monomer components are used for the polymerization either submitted in total in aqueous solution and by Polymerized addition of the initiator system or over a period of 1 to 10 hours in the polymerization reactor dosed. In one embodiment of that in DE-A-4300772 Process described are the dicarboxylic acids, dicarboxylic anhydrides and at least a portion of the hydrolyzable or saponifiable monomers together in the reaction vessel submitted and the remaining monomers during the polymerization added and the polymerization optionally in closed polymerization reactor carried out. Here the dicarboxylic anhydride can be hydrolyzed prior to polymerization and be at least partially neutralized. The final one Hydrolysis or alkaline saponification can take place in the presence of peroxides, e.g. Hydrogen peroxide, or with Sulfur dioxide is preferably carried out after the polymerization become.

The copolymers act as dispersants and complexing agents. With you polyvalent metal ions, e.g. B. Ca, Mg and Fe ions, in water-soluble Complex bound. The copolymers disperse precipitated ones Water hardness and dirt particles. The products are characterized by a good environmental compatibility. On the use of previously used Complexing and dispersing agents, such as. B. phosphates, phosphonates, non-degradable polyacrylates, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), which have ecological disadvantages usually be dispensed with.

For the purposes of this invention, the copolymers are biodegradable if they in the modified OECD storm test (EC Directive 84/449 / EEC C 5 and OECD Guideline 301 B) (see e.g. Soap-Oil-Fat-Waxes 117 (1991), 740 to 744), have a degree of degradation of ≥ 60%.

In addition to the copolymers, the formulations also contain water-softening agents inorganic silicates b, such as. B. Zeolite A type sodium aluminum silicates and / or crystalline sodium silicates with layer structures. Preferably are the inorganic silicates with proportions from 30 to 80% by weight, based on the anhydrous substance.

Furthermore, other inorganic salts, preferably, as component c Alkali and ammonium salts of sulfuric, hydrochloric and carbonic acid, be included. Sodium sulfate can be found in powder products and granules improve the grain structure and a beneficial effect on the Have washing behavior in the washing machine. Such inorganic salts if you have included them in the recipes, preferably 20 up to 60% by weight.

Component d is preferably 2 to 40% by weight in the formulations contain. Suitable dispersing and complexing agents are, for example Citrates, phosphonates, isoserine diacetic acid, homo- and copolymers acrylic acid as well as ethylenediaminetetraacetic acid and nitrilotriacetic acid and salts of the aforementioned compounds.

The formulations can also contain 0 to 5% by weight of anionic, have nonionic or cationic surfactants.

In addition, the formulations generally contain customary formulations Additives such as B. water-soluble alkali metal or alkali disilicates as Corrosion inhibitors as well as perfume oils and dyes in total amounts 0 to 30% by weight.

The formulations according to the invention can be in the form of liquids, in powder form Products or granules are used.

The liquid formulations can be prepared by mixing the Components are done. The powdered products are usually by mixing the powdered constituents and, if necessary, by Spraying on the liquid constituents or by spray drying an aqueous, liquid to pasty approach of the starting components.

The formulations according to the invention can be used as water softeners become. If there is increased water hardness, you can also use the Detergents and cleaning agents are added.

Compared to formulations in which component a is made by a commercially available Compound replaced, are the formulations of the invention better in effect or at least equally good. The now claimed Formulations also have an improved biological Degradability.

The following examples are intended to illustrate the invention.

example 1 Copolymer

By radical polymerization of 35 wt .-% maleic anhydride in Form of sodium maleate, 45% by weight acrylic acid and 20% by weight vinyl acetate in aqueous solution and saponification, a copolymer with a medium obtained molar mass of about 15,000 g / mol.

The copolymer obtained in aqueous solution is spray dried in transferred a powdery product.

Example 2 Biodegradability

The biodegradability of the copolymers is modified according to the OECD storm test in accordance with EC Directive 84/449 / EEC C 5 and the OECD Guideline 301 B tested.

For the substance mentioned in Example 1, a degree of degradation of over 60% determined.

Commercial polycarboxylates, such as. B. homopolyacrylates and copolymers from acrylic acid and maleic acid, on the other hand, have lower biodegradability on.

Example 3 Wording

Powdery water-softening formulations of the following composition are prepared from the copolymer of Example 1: 1 % 2% 3% Zeolite A 80 60 40 Copolymer, powdery 20th 15 10th Sodium sulfate, light - 20th 30th Sodium citrate dihydrate - - 20th Sodium disilicate - 5 -

Comparative formulation: 4% Zeolite A 80 Commercial polycarboxylate 20th

Example 4

1.0 g / l of formulation 1 according to the invention or of comparison formulation 4 together with 5 g / l of a detergent formulation typical of the market consist of 8th % n-alkylbenzenesulfonate, Na salt 6% Fatty alcohol ethoxylate 2% Soap 25% Zeolite A 6% Acrylic acid-maleic acid copolymer, Na salt 17% sodium 5% Sodium metasilicate pentahydrate 20% Sodium perborate tetrahydrate 5% Tetraacetylethylenediamine 1 % Carboxymethyl cellulose 5% Sodium sulfate, light washed in a Lini-Test laboratory washing machine. Wash cycles 10 washes Washing temperature 90 ° C Water hardness 30 ° dH

The addition of the water softener reduces the deposits on the fabric. The following table shows the ash content as a measure of the deposits. formulation 1 4th Ash content (%) 2.3 2.5

When using the water softening formulation 1 according to the invention less tissue incrustation than in the comparison formulation 4, which corresponds to the state of the art.

The claimed formulations are therefore biological Degradability and tissue incrustation improved.

Claims (5)

1. Water-softening compositions, containing

   (a) from 5 to 80 wt.-% of biodegradable copolymers which have a degradability of ≥60% and may be obtained by free-radical polymerization of

   A. monoethylenically unsaturated dicarboxylic acids and/or salts thereof,

   B. monoethylenically unsaturated monocarboxylic acids and/or salts thereof,

   C. mono-unsaturated monomers which, following polymerization and hydrolysis or saponification, yield monomer units having one or more hydroxyl groups on the carbon chain, and

   D. from 0 to 15 wt.-% of other free-radical-copolymerizable monomers,

   in an aqueous medium, and subsequent hydrolysis or saponification of the polymerized monomer units according to C.,

   (b) from 10 to 95 wt.-% of water-softening inorganic silicates,

   (c) from 0 to 80 wt.-% of other inorganic salts,

   (d) from 0 to 70 wt.-% of dispersing and complexing agents, and

   (e) from 0 to 5 wt.-% of surfactants,

   relative to the anhydrous substance.
2. The compositions of claim 1, characterized in that component (a) is contained at a level of from 5 to 30 wt.-%.
3. The compositions of claim 2, characterized in that component (b) is contained at a level of from 30 to 80 wt.-%.
4. The compositions of claim 1, characterized in that component (d) is contained at a level of from 2 to 40 wt.-%.
5. Use of the compositions according to claim 1 as water softeners.