NO781898L - LIQUID DETERGENT MIXTURE. - Google Patents

Description

"Liquid detergent mixture".

The invention relates to a detergent mixture, in particular

an anhydrous non-ionic detergent mixture containing builders.

Heavy duty detergent mixtures for use e.g. in household washing machines is usually sold in powder form. The advantage of a powder is that it makes it possible to incorporate a wide range of inorganic builders into the product, further than if you made an aqueous mixture because some builders, e.g. sodium tripolyphosphate, are unstable in the presence of water and others, e.g. sodium perborate, in the presence of water oxidizes organic components in the product. It is also impossible to make a homogeneous liquid, aqueous mixture with organic surfactant and the desired amount of inorganic builders. The disadvantage of a powder is from the manufacturer's point of view that it is relatively expensive to produce. Compared to an equivalent aqueous product, a powder requires more expensive drying equipment for manufacture, and as well as being expensive, such equipment is often difficult and occasionally dangerous to operate.

A product has now been found which is liquid and which contains organic surfactants and builders of the type, and in the concentration, which could previously only be obtained in powder form.

According to the invention, a liquid detergent mixture comprises a dispersion of one or more builders in an essentially water-free, non-ionic liquid surfactant which contains a dispersant for the builder.

Any builder known for use in detergent mixtures can be used in the product according to the present invention. In general, such builders are inorganic in nature, but some organic products, especially sodium carboxymethyl cellulose, can be used. Suitable inorganic builders include phosphates, e.g. trisodium phosphate, tetrasodium pyrophosphate, sodium hexametaphosphate and, preferably, sodium tripolyphosphate, carbonates, e.g. sodium carbonate, sodium bicarbonate and sodium sesquicarbonate, clay, e.g. kaolin, montmorillonites and sodium bentonite, as well as various salts, e.g. sodium borate, sodium perborate, sodium percarbonate, sodium metasilicate, sodium sulfate and sodium chloride. The potassium analogues of these sodium compounds can also be used. It is preferred that a mixture of builders is present in the product, e.g. sodium tripolyphosphate, sodium metasilicate and sodium perborate.

In order to provide an effective dispersion of the builder(s) in the liquid non-ionic surfactant, it is desirable that at least 90% of the particles of the builder have particle sizes of less than 100, preferably less than 10 µm in diameter. The product contains a dispersant to facilitate and stabilize the dispersion. we have found that a particularly effective dispersant is a combination of finely divided silicon dioxide (particles with a diameter of 5-100, preferably 7-40> millimicrons) such as e.g. sold under the trade name "AER0SIL", which can be used in conjunction with a compound containing one or more polyether groups. The compound containing the polyether group(s) preferably has a molecular weight in the range 500-1,000,000, more preferably 20,000-100,000. The compound containing the polyether group(s) may be the result of grafting polyether chains onto a suitable substrate, e.g. in a single case, the product from the reaction of glycerol with ethylene oxide. Numerous substrates are known to be susceptible to reaction with an olefin oxide to give a polyoxyalkylene chain comprising ether groups, e.g. substrates which are compounds containing one or more carboxyl, hydroxyl or amino groups. The most convenient substrate is water, which reacts with an alkylene oxide to form a polyalkylene glycol. Although polyethylene glycol is preferred, polypropylene glycol, polybiethylene glycol and glycols derived from mixtures of ethylene oxide and/or butylene oxide can also be used. In the latter case, the glycol can contain the various alkylene oxides in any arrangement or in the form of blocks of the respective polyalkylene oxide. The preferred compound containing the polyether group(s) is polyethylene glycol with a molecular weight in the range of 60,000-100,000.

The non-ionic surfactant which is a component of the mixture according to the invention is also preferably an alkylene oxide derivative. In particular, the nonionic surfactant may be an alkylene oxide derivative of an amide, an alkylphenol or an alkanol. The alkyl group in the alkylphenol can be straight-chain or branched and can contain 6-20 carbon atoms, e.g. para-nonylphenol or para-dodecylphenol. The alkanol may contain 6-20 carbon atoms, especially 10-16 carbon atoms. The alcohol is preferably a primary or secondary alkanol having a linear or mono-branched alkyl group.

The product can suitably comprise two non-ionic surfactants, one of which fulfills a surface-active function and the other fulfills a surface-active function and reduces the product's pour point. The former surfactant can e.g. include alcohols having 12-16 carbon atoms that are alkoxylated with 5-15 moles of ethylene and/or propylene oxide; the other surface-active agent can be a C 8 -alcohol alkoxylate with a linear or branched chain comprising 2-8 mol of ethylene and/or propylene oxide per mol, branched-chain alcohols being preferred in the Cg_1-^ range and linear alcohols in the g-range, or an alkylphenol alkoxylate which has 2-6 mol of ethylene and/or propylene oxide per molecule, as the alkyl group is often in the para position and has 6-12 carbon atoms.

An additional surfactant of the anionic or cationic type may be included if desired. Such anionic or cationic surfactants can be of a known type, e.g. the anionic detergents can be soaps, alkylbenzene or olefin sulfonates, alcohol sulfates or alcohol alkylate sulfates; the cationic surfactants are usually di-C^ and preferably di-C^g_^g-alkyl, di-lower-alkylammonium salts or hydroxides, e.g. chlorides or sulfates. The lower alkyl groups are usually methyl groups.

In general, however, the alkylphenol or alkanol derivative may comprise 2-20 alkylene oxide units which are preferably ethylene oxide units, although a small number of propylene oxide or a smaller number of butylene oxide units may also be present. The amide is preferably a mono- or di-alkanolamide, e.g. a mono- or di-ethanolamide, preferably of a C, -C0/_-, more preferably a C, -C,_-o JO XO£0alkanoic acid, e.g. coconut acids, tallow acids or stearic acid.

An alternative nonionic surfactant for use

in a product according to the invention comprises a copolymer of ethylene oxide with propylene oxide and/or butylene oxide. The copolymer

comprises a block of propylene and/or butylene oxide units onto which ethylene oxide is grafted. The block preferably comprises 20-40 propylene oxide units, especially approx. 30 such units and 20-30, especially approx. 26 ethylene oxide units.

It is a feature of the product according to the invention that the dispersion of the builder or builders in the non-ionic surfactant is particularly stable. If the builder or builders separate at all, then the resulting phase is loosely flocculated and easily redispersible, but if the relative amounts of the builder or builders and the nonionic surfactant in the product are chosen correctly, then there is little phase separation the liquid fills the space between the loosely packed builder particles. The product may contain 20-70% by weight builder(s). It is preferred that the product contains 30-60% by weight and more preferably 40-60% by weight of builder(s), the remainder preferably being essentially non-ionic surfactant together with the dispersant. The amount of dispersant present is usually up to 5% by weight, but the product may also contain additives that are conventionally used in detergent mixtures, e.g.* optical brighteners, ethylenediaminetetraacetic acid, dyes, perfume or enzymes. In the following, the invention will be described by means of examples. in that the components were mixed and then stirred for 20 minutes with a high shear homogenizer. 2 parts by weight of finely divided silicon dioxide ("AEROSIL") was then added and mixed into the above mixture by stirring for the shortest possible time.

The nonionic surfactant comprised a mixture of 8 7.4% by weight alcohol alkylates (derived from a mixture of C^^~°9ci5~Primary alcohols comprising 55% straight chain and 45% chains with a methyl-

branching in the 2-position alkoxylated with a mixture of ethylene oxide (92% by weight) and propylene oxide (8% by weight)

so that an average alkylene oxide chain length of 9 was obtained).

10.9% by weight coconut acid diethanolamide and 1.7% by weight "Fluolite" (optical brightener).

The two products were stable, and the dispersion was not broken even after 3 weeks of storage at 0°C, ambient temperature, or at 50°C.

In washing tests, the products proved to be approximately as effective, under comparable conditions, as three different commercial powders.

Example 2

Products were made from the following components:

C-^Q-alcohol derived by hydroformylation of propylene trimer and

ethoxylated with an average of

6 ethylene oxide units per molecule. 10.5 A surface-active mixture comprising 8 7.4% by weight of alcohol alkylates

(derived from a mixture of C-^- and

C-j^- primary alcohols comprising 55%

straight-chain and 45% with a methyl branched in the 2-position alkoxylated with a mixture of 92% by weight ethylene oxide and 8

% by weight propylene oxide so that one got

an average alkylene oxide chain-

In the second product, the ethoxylated isodecanol was replaced with an ethoxylate of a mixture of C₁-C₂ primary alcohols comprising approximately 30% by weight linear, 60% by weight branched and 10% by weight alicyclic alcohols. The ethoxylate contained an average of 6 ethylene oxide units per molecule.

The two products were stable, and the dispersions were not broken after 3 weeks of storage at 0°C, ambient temperature and 50°C, respectively, while the detergency of the two products was comparable to commercial powders.

It should also be noted that the dispersant used in the two products described above was "AEROSIL" alone, compared to the dispersant described in Example 1 which included "AEROSIL" and a polyethylene glycol.

Example 3

Four products were made which were according to the invention, as indicated in example 1, using the following components:

The above products are low-foaming detergents that are suitable for use in automatic washing machines.

Products (c) and (d) are detergents that foam strongly and are suitable for use in washing machines with two containers. The sodium tri-polyphosphate, the silicate and the percarbonate were anhydrous in all cases.

The above products were tested for washing efficiency and compared with three well-known commercial washing powders in the following way: Fabric pieces. with the dimensions 10.16 cm x 7.62'cm of standard soiled cotton laundry from Krefeld was washed in 1 liter of test solutions for 10 minutes at 50°C and 100 rpm. my. in a Tergotometer. The powders were used in a concentration of 5 g/l, and the products according to the invention in a concentration of 1.25 g/l. The light reflection before and after washing was measured using a Gardner Reflectometer and the difference in reflectivity before and after washing, which is a measure of the efficiency of the washing process, was measured. The results were as follows:

Product (a): reflectivity change 29 units,

Product (b):" " 29 "

Products (c) and (d): reflectivity change 27 units.

The powder detergents produced reflectance changes of 30, 28 and 27 units respectively. These results indicate comparable washing efficiency using the products according to the invention in the above concentrations.

Example 4

A product was made as described in example 1,

of the following components:

The washing test of Example 3 was repeated using the above product and compared with the best of the powder detergents tested in Example 3, but using "Empa" soiled cotton test squares at 60°C. The reflectivity change in the powder detergent was 21 units, and for the product it was 28 units.

A product was obtained by the addition of 7 mol of a mixture of ethylene oxide and propylene oxide in a molar ratio of 92:8 to a mixture of C-^-C-^^ primary alcohols of which 55% had straight chains and 45% 2-methyl-substituted chains.

"Synperonic" and "Alphanol" are trade names of Imperial Chemical Industries Ltd.

Claims (7)

1.F flowing detergent mixture, characterized in that it comprises a dispersion of one or more builders in an essentially water-free non-ionic liquid surface-active agent which contains a dispersant for the builder. 2. V ash mixture as stated in claim 1, characterized in that at least 90% of the particles of the builder are smaller than 10^/ um in diameter. 3. V ash mixture as stated in any of the preceding claims, characterized in that the dispersant comprises finely divided silicon dioxide in which the average diameter of the silicon dioxide particles is preferably 7-40 millimicrons. 4. V ash composition as set forth in any of the preceding claims, characterized in that it comprises (a) a non-ionic surfactant which is an alkoxylate of a C-^ 2-C .^-alcohol with 5-15 mol ethylene and/or propylene oxide per mol alkoxylate and (b) an alkoxylate of a linear or branched C 8 -C 3 -alcohol with 2-8 mol ethylene oxide per mol and/or an alkoxylate of an alkylphenol with 2-6 moles of ethylene and/or propylene oxide per mol. 5. Detergent mixture as stated in any of the preceding claims, characterized in that it comprises a non-ionic or cationic surfactant. 6. Detergent mixture as stated in any of the preceding claims, characterized in that it comprises 30-60% by weight of builder, the remainder essentially being non-ionic surface-active agent together with the dispersant. 7. A process for washing laundry in water, comprising contacting the laundry with an aqueous solution, agitating the laundry to separate it from soiling materials, and removing the laundry from the water, characterized in that a product as set forth in any of the previous requirements are dissolved in the water.