NO135323B - - Google Patents

Description

Detergent mixture.

The invention relates to detergent mixtures which comprise vinyl polymers as dirt-carrying agents.

Modern textiles, especially those made of synthetic material or a mixture of natural and synthetic material, or chemically modified cotton, show a tendency to turn gray when washed.

So far, sodium carboxymethyl cellulose has been used

largely in detergent mixtures to reduce dirt deposition during the washing process. While it is a very effective dirt-carrying agent for cotton and similar materials, it is however ineffective as a dirt-carrying agent for synthetic materials, especially polyester fabrics. In recent years, vinyl compounds, namely polyvinyl alcohol and polyvinyl pyrrolidone, have been proposed as

dirt-carrying means for preventing the renewed deposition of dirt, as disclosed in the German patent documents Nos. 1,156,927 and 1,293,378, but with very little success. Furthermore, it has now been established that especially polyvinyl alcohols with a high molecular weight show disadvantages during the processing and use of detergent mixtures containing these materials. These substances tend to agglomerate in the slurry, which may be caused by their tendency to be salted out by electrolytes. The result is that coarse particles form, and these in some cases grow into large lumps that stick to the stirring elements in the slurry mixer. When added as a fine powder to the final mixture to overcome this difficulty, their agglomerating tendency still causes the formation of undissolved flakes during the washing process, and these are apt to stick to the laundry, especially to knitted garments that need to be delicately washed.

It has now been found that copolymers of vinyl pyrrolidone and vinyl acetate are good dirt carriers for synthetic and similar—

nd material without showing the above disadvantagesE. These copolymers already show, when used in small quantities, the prevention of renewed deposition of dirt on synthetic material, as sodium carboxymethyl cellulose does on cotton. The specific or exact degree of polymerization is not critical, provided that the material has the desired water solubility. In general, the suitable vinyl pyrrolidone/vinyl acetate copolymers have an average molecular weight usually in the range of approx. 10,000 to approx. 400,000 and preferably from approx. 20,000 to approx. 200,000. Such copolymers are known from US Patent No. 2,667,473 and have been commercially available, but their use as soil-carrying agents has so far not been described. Their degree of effectiveness in reducing re-deposition of dirt is dependent on the ratio between the vinylpyrrolidone-(VP) and vinylacetate-(VA) portion in the copolymer. Optimum activity was observed at a VP : VA molar ratio of 50 : 50. The preferred copolymers according to the invention are those which have a VP : VA molar ratio of between 10 : 90 and 90 : 10, more preferably between 30 : 70 and 70 : 30.

The VP/VA copolymers can be incorporated into liquid as well as particulate or solid detergent mixtures. Used in particulate detergent compositions, they can be mixed with the other ingredients in a conventional manner during the preparation of the slurry, followed by spray drying. Some degree of hydrolysis of the acetate part of the copolymer can take place during the preparation, without this having an effect on the physical properties of the slurry or on the powder properties or the preparation. The spray-dried powder shows no increase in hygroscopicity at all at the VP/VA copolymer content and retains its free-flowing properties during storage.

The invention therefore provides a detergent mixture which essentially comprises a detergent-active compound and a copolymer of vinyl pyrrolidone and vinyl acetate as defined above.

In general, the amount of the vinyl pyrrolidone/vinyl acetate copolymer used as a soil carrier in the composition should be a minor proportion of the composition, e.g. 0.1 to 5.0% by weight of the detergent mixture, preferably from 0.2 and up to 2.0% by weight.

The detergent-active compound in the composition according to the invention can be any of the conventional anionic, non-ionic, cationic or ampholytic detergent-active compounds normally used in laundry detergent compositions. Examples of suitable detergent-active compounds are: alkylarylsulfonates, alkyl or alkane sulfonates, alkyl sulfates, alkyl phosphates, mixtures of anionic detergent-active compounds produced by sulfonation with sulfur trioxide, and subsequent hydrolysis and neutralization of unsaturated hydrocarbons (usually called olefin sulfonates), ethoxylated alcohols, ethoxylated alkylphenols, ethoxylated amines, ethoxylated fatty acid amides, sulfates and phosphates of these ethoxylated materials, amine oxides, isothionates, Cg-C^ fatty acid soaps, taurines, betaines and sulfobetaines. Mixtures of these wax-active compounds can be used if desired. They normally make up 2 to 60% by weight of the detergent mixture, but the soap powder or soap flakes generally have a much higher content of detergent-active material, i.e. up to 95%.

In addition to the detergent-active compound and the VP/VA copolymer, a mixture according to the invention may comprise any of the other conventional ingredients in detergent mixtures, e.g. fatty acid amide foam enhancers, e.g. coconut ethanolamide and palm kernel ethanolamide, inorganic and organic detergency builders, e.g. sodium tripolyphosphate, trisodium orthophosphate and sodium nitrile triacetate, hydrotropes, e.g. sodium xylene sulphonate, sodium toluene sulphonate etc, additives to prevent corrosion and destruction of the laundry, e.g. silicates, inorganic salts, e.g. sodium sulfate and sodium carbonate, bleaching agents, e.g. sodium perborate, sodium percarbonate and sodium chlorocyanurates, and finally, usually present in small amounts, perfumes, dyes, fluorescent agents, germicides, enzymes and other soil carriers, e.g. sodium or potassium carboxymethylcellulose. The latter agent can be present in the mixture in amounts of the same order of magnitude as the soil-carrying agent according to the invention, namely 0.1-5.0% by weight, without affecting the performance of any of the others.

The following examples illustrate features of the invention in greater detail.

EXAMPLES I- II

The soil-carrying properties of two VP/VA copolymers were compared with the values of polyviriylpyrrolidone in a conventional powdered non-ionic detergent composition, at using the following test method. A vertical washing machine equipped with a mechanical stirrer was used.

The above table clearly shows the good soil-carrying effect of the copolymers according to the invention in a non-ionic detergent mixture.

EXAMPLES III-VI

The soil-carrying properties of four VP/VA copolymers were compared with the values of other polymeric compounds in a conventional powdered detergent composition containing soap. The test method explained in examples I-II was used.

<1>^ Example 3: VP/VA copolymer 50:50 (from GAF, sold under the trade name "ELFA" E 53 5) Example 4: VP/VA copolymer 20:80 (from BASF, sold under the trade name trade name "Luviskol" VA 28) Example 5: VP/VA copolymer 50:50 (from BASF, sold under the trade name "Luviskol" VA 55E) Example 6: VP/VA copolymer 60:40 (from BASF, sold under trade name "Luviskol" VA 64) Example D: Alkyl monoester of poly(methyl vinyl ether) (from GAF, sold under the code name ES 225) Example E: Styrene-acrylic ester copolymer (from Hoechst, sold under the code name DM60)

Table II above shows that even in soapy mixtures the effect of the VP/VA copolymers is still clearly noticeable.

EXAMPLE VII

The soil-carrying properties of the mixture from Example V were tested by washing naturally soiled material in a Schultheiss drum-type washing machine for the synthetic wash cycle with a maximum temperature of 60°C. The degree of whiteness after 25 and 50 washes, measured with the "Elrepho" photometer , was compared to a similar blend without VP/VA copolymer present, with the exception that sodium carboxymethyl cellulose was present as a soil carrier in cotton fabrics in conventional blends (blend F). These results are shown in table III. Test conditions.

Normally soiled white laundry was washed together with cotton, nylon, polyester and "Splendesto" samples.

Amount of laundry: 4 kg

Concentration of detergent: 5 g/l

Water hardness: 20° German hardness

Bath ratio: 1:6

Washing temperature: 60° C

EXAMPLES VIII-XI

The following powdered detergent mixes were made without difficulty and were equally good in terms of powder structure and performance.

EXAMPLES XII- XIV

Liquid mixtures comprising VP/VA copolymers recommended for fine washing.

<1>^ Example 12: VP/VA copolymer 50t50, from BASF

Example 13: VP/VA copolymer 20:80 from BASF Example 14: VP/VA copolymer 60:40 from BASF

Claims (4)

1. Detergent mixture for cleaning textiles, containing an anionic, non-ionic or arapolytic surface-active compound as well as commonly used detergent ingredients, characterized in that the mixture as dirt carrier contains 0.1-5.0% by weight of a copolymer of vinylpyrrolidone and vinyl acetate, where the copolymer has an average molecular weight in the range of 10,000 to 400,000 and a vinyl pyrrolidone/vinyl acetate molar ratio of between 10:90 and 90:10. 2. Detergent mixture as stated in claim 1, characterized in that the copolymer has an average molecular weight of between 20,000 and 200,000. 3. Detergent mixture as stated in claim 1, characterized in that the amount of copolymer is 0.2 to 2.0% by weight of the detergent mixture. 4. Detergent composition as set forth in any one of claims 1 to 3, characterized in that it also contains an alkali metal carboxymethylcellulose in an amount of 0.1-5.0% by weight of the composition.