NO131603B - - Google Patents

Description

Built detergent mixture.

The invention relates to synthetic detergents, in particular detergents which are adapted for dry washing, as well as new detergent builders and their production.

Conventional detergents are based on detergent-active compounds and detergency builders, the most common of which are the condensed phosphates, e.g. sodium tripolyphosphate. It has been suggested that the use of phosphorus-containing detergency builders may be a contributing factor in eutrophication, i.e. the high degree of fertilization of aquatic plants. It has been proposed to use as detergency builders certain non-phosphate-containing compounds, but the materials suggested tend to suffer from disadvantages, either with regard to the physical properties which reduce their use in the washing powder, or they suffer from poor detergent-building properties.

In US-PS 3,459,670, it is specifically proposed to use cycloalkane-polycarboxylic acids, e.g. cyclopropane and cyclopentane tetracarboxylic acids, but these materials are not sufficiently biodynamically degradable for commercial use in detergent mixtures,

According to the invention, phosphorus-free detergency builders for use in detergents are water-soluble or water-dispersible salts of furanic or tetrahydrofuran-tetracarboxylic acids, which have formulas I and II respectively

The alkali metal salts are preferred, especially the sodium salts, but the salts with ammonium and substituted ammonium cations, e.g. morpholine, alkyl ammonium and mono-, di- and trialkanolammonium can be used if desired. The alkyl and alkanol ammonium cations generally contain lower alkyl groups with 1 to 3 carbon atoms.

Detergents can be made from these furan or tetrahydrofuran-tetracarboxylate builders with washing properties, while not containing phosphorus. The tetrahydrofuran tetracarboxylates are the most effective builders.

Examples of suitable salts are the tetrasodium, tetrapotassium, tetralithium and tetraammonium tetrahydrofuran tetracarboxylates, the monoethanolamine, diethanolamine and triethanolamine salts of tetrahydrofuran tetracarboxylic acid, the tetra (tetramethylammonium) and tetra (ethylammonium) tetrahydrofuran tetracarboxylates, mono-, the di- and triisopropanolamine salts of tetrahydrofuran-tetracarboxylic acid, monosodium tripotassium, disodium dipotassium and trisodium monopotassium tetrahydrofuran tetracarboxylates, morpholine tetrahydrofuran tetracarboxylate and the corresponding furan tetracarboxylates.

It should be understood that the normal salts, i.e. the fully neutralized salts, will usually be used in detergents, although neutralization can be carried out in the washing liquid if desired. However, if the pH value of the washing solution is below approx. 8.6, some of the salts of the furan- or tetrahydrofuran-tetracarboxylic acid be present in the acid salt form and some in the normal salt form.

When detergent builders are used in detergents, it is necessary that one or more detergent-active compounds are also present. Suitable detersive compounds include anionic (soap and non-soap), nonionic, zwitterionic and amphoteric compounds well known in the art. Specific compounds of which examples can be given are alkyl benzene sulfonates, alkyl and alkyl ether sulfates, alkyl sulfonates, olefin sulfonates (by this term is meant the sulfonation product with sulfur trioxide of an olefin, followed by neutralization and hydrolysis of the reaction product), N-hydroxyalkylmethyl taurines , trialkylammonium alkanesulfonates and polyalkylene oxide condensates with aliphatic alcohols and alkylphenols. Further examples can be found in the literature, e.g. in "Surface Active Agents" by Schwartz and Perry and "Surface Active Agents and Detergents" by Schwartz, Perry and Berch.

The weight ratio between the furan or tetrahydrofuran-tetracarboxylate detergency builders and the detergent-active compounds when these are used in detergents for laundry and manual dishwashing generally varies from approx. 1:20 to approx. 20:1, preferably from approx. 1:3 to 10:1, especially from approx. 2:1 to 5:1. However, when these detergency builders are used in detergents for dishwashers, the ratio between detergency builder and the detergency-active compound is generally from approx. 10:1 to 50:1. The amount of washability builder is generally in the range from approx. 25 to 75% by weight.

The furan and tetrahydrofuran-tetracarboxylate detergency builders can be used either as the only detergency builders, or if desired they can be used in conjunction with other known detergency builders, e.g. tetrasodium and tetrapotassium pyrophosphates, pentasodium and pentapotassium tripolyphosphates, trisodium and tripotassium nitrile triacetates, sodium polyacrylate, sodium copolyethylene/maleate and the like.

The detergents according to the invention may include conventional additives including e.g. dirt-carrying agents, hydrotropes, corrosion inhibitors, dyes, perfumes, fillers, optical brighteners, enzymes, foam enhancers, anti-foam agents, bactericidal agents, anti-staining agents, cationic washing-active compounds, softeners, bleaches and the like. When the detergents according to the invention are used for washing clothes, the washing solutions should normally have a pH value of approx. 7 to approx. 12, preferably from approx. 9 to approx. 11. Therefore, it is usually desirable to include a pH buffer in the detergent, e.g. sodium silicate, carbonate or bicarbonate. The rest of the detergents are made up of water.

The detergents can have any of the usual physical forms for such products, e.g. powders, beads, flakes, bars, pieces, noodles, liquids, pastes and the like. The detergents can be prepared and used in a conventional way.

The tetrahydrofuran-tetracarboxylate detergent builder salts can

easily prepared by neutralization of tetrahydrofuran-tetracarboxylic acid with the appropriate base. Thus, e.g. the pure tetrasodium salt is prepared by dissolving the commercially available acid in a slight excess of dilute NaOH. Approximately 4 parts by volume of ethanol are added, and a white precipitate forms which is filtered. The precipitate is redissolved in water and Jelles again in the same way

again 3 more times, after which the salt is dried in a vacuum oven at 105°C. The product is essentially pure tetrasodium tetrahydrofuran tetracarboxylate, which is shown by titrating a sample with perchloric acid in glacial acetic acid.

Likewise, the mixed salts of tetrahydrofuran-tetracarboxylic acid can be prepared by neutralizing the acid with the necessary relative amounts of basic compounds containing the

desired cations.

The tetrasodium salt of tetrahydrofuran-tetracarboxylic acid has

no melting point, but decomposes before it melts. Differential thermal analysis of the material indicated that the cleavage did not begin

below 400°C. Thus, this material is able to counter-

withstand high processing temperatures.

The furan tetracarboxylates can likewise be prepared by neutralization of furan tetracarboxylic acid. The production of the acid is described in Hel v. Chem, Acta, JL6 276 (1933) and involves the condensation of 2 molecules of sodium diethyloxaloacetate with bromine in chlorine

form that gives a tetraester compound that is cyclized in concentrated sulfuric acid so that you get tetraethylfuran-tetracarboxylate which is then hydrolyzed to the acid. Tetrahydrofuran-tetracarboxyl-

acid can be prepared by reduction of furan-tetracarboxylic acid or it can be synthesized directly, e.g. by oxidation of endoxotetrahydrophthalic acid or its anhydride with nitric acid.

Detergents according to the invention shall be illustrated

by the following examples, which include comparative products,

where parts and percentages indicate weight unless otherwise stated. The washing properties of the different products are included in the examples. Unless otherwise stated, the washability tests were carried out in a Terg-O-Tometer where a test piece of "Dacron" (RTM) polyester 65%/cotton 35% soiled with vacuum cleaner dust was washed at 49°C in a 0, 15% solution of the detergent that should

investigated, in water containing 180 ppm calcium and magnesium ions (2:1), at an initial pH value of 10. The average washability units (VE) of the products were calculated as the final reflectance of the washed garment minus the initial reflectance of the soiled cloth (average of 2 trials), the reflectance being measured with a Gardner Automatic Color Difference Meter, Model AC-3.

EXAMPLES 1 to 11.

A variety of detergents were prepared by mixing the ingredients, and their detergency was measured. The compositions and detergency are shown in Table I below.

These results show that the tetrahydrofuran tetracarboxylate is generally equivalent to sodium tripolyphosphate, especially at lower concentrations of the detergency builders.

EXAMPLES 12 to 17.

A variety of detergents were prepared as indicated in the examples

1 to 11, but the sodium silicate was omitted from the products. Together-in/

sentences and wash capacities are shown in Table II below:

These results show that the tetrahydrofuran tetracarboxylate is only slightly inferior to sodium tripolyphosphate in the absence of the sodium silicate buffer.

EXAMPLE 18.

The products from Examples 1 and 2 were examined for washability in water with different degrees of hardness, and the results are shown in Table III below:

The results show that the products according to example 1 with tetrasodium tetrahydrofuran tetracarboxylate are approximately equivalent with respect to washing ability over a wide range of degrees of hardness, with the sodium tripolyphosphate-based product.

EXAMPLES 19 to 26.

A variety of detergents were made using different detergent active compounds as shown in Table IV below, which includes the wash test results:

The washing ability-

named (average) '27.9 31.4 27.1 29.9 29.2 30.8 24.7 27.3

"^A non-ionic detergent active compound which is an adduct of a modified "OXO"-type C-^-C^-alcohol with an average of 11 moles of ethylene oxide. 2)'Measured for Examples 19 to 22 in 0.2 % concentration and for

examples 23 to 26 in 0.15% concentration.

These results show that the tetrahydrofuran-tetracarboxylate is an effective detergency builder for the non-ionic, zwitterionic and amphoteric detergent-active compounds.

EXAMPLES 27 to 32.

A number of detergents were produced with mixtures of tetrasodium tetrahydrofuran tetracarboxylate and sodium nitrile triacetate as detergency builders. The compositions of the products and of the products with each of the materials as the only detergency builder and with sodium tripolyphosphate as detergency builder, as well as the washing test results are shown in table V below:

EXAMPLE 33.

A detergent was produced with the following composition:

The detergency of this product and of a comparison product A with sodium tripolyphosphate as detergency builder instead of tetrasodium tetrahydrofuran tetracarboxylate was determined at different concentrations. In the method for determining detergency, a solution of the product in water of 18°H (Ca:Mg,2:l) at 45°C was used to wash a sample piece of cotton, impregnated with carbon-14-labeled synthetic sebum in a Terg-O-Tometer for 10 minutes, and the radioactivity in the piece of cloth was measured before and after the wash. The washability is % change in radioactivity.

The results for Example 33 and Comparative Product A are shown in Table VI below:

These results show that the tetrahydrofuran tetracarboxylate is generally equivalent to sodium tripolyphosphate for the removal of greasy soil, especially at low product concentrations.

EXAMPLE 34.

A detergent was made with the following composition:

This product was used to wash in a normal household soiled pillowcases, napkins and towels in a household washing machine.

machine of the brand "Hotpoint" Empress using water of 18°H (Ca:Mg,

2:1) at 45°C. Similar tests were performed using a wash-

agent of the same composition, but where the detergency builder was sodium tripolyphosphate, with each object being divided into 2 and each half

part washed with different detergent. The washed objects were assessed visually with regard to appearance, and in most cases no difference was noted, but where there was a difference, the objects that had been washed in the detergent were

keep to the invention, preferred.

Example 35.

A detergent was made with the following composition:

The washing properties of this product were measured by the method described above, using a Terg-O-Tometer, in comparison with a similar product where the tetranate tetracarboxylate was replaced by sodium tripolyphosphate. It turned out that at 0.2% concentration the detergency building effect of the furan tetracarboxylate was only 67% of the value for sodium tripolyphosphate, but this still represented a significant improvement in relation to the use of the detergent active compound without any detergency builder.

Claims (1)

Constructed detergent mixture comprising from 25 to 45% by weight of an anionic, zwitterionic or amphoteric detergent-active compound and a builder, characterized in that the builder is a water-soluble or water-dispersible alkali metal, ammonium or substituted ammonium salt of furan or tetrahydrofuran-tetracarboxylic acid, the weight ratio between the detergent-active compound and the building salt is from 3:1 to approx. 1:10.