Laundry Softener Concentrate

The present invention relates to a laundry softener concentrate.

Laundry softeners are added to washing liquids to improve hand and to increase the softness of textile fabrics washed therein. Such softeners most usually are cationic tetraalkylammonium compounds and imidazoline derivatives, the effectiveness of which depends on the chemical nature of the alkyl groups.

Since, because of these long-chain alkyl residues, these laundry softeners are not soluble in water, they are conventionally marketed in the form of a 5%-8% by weight aqueous dispersion. This great dilution has obvious economic disadvantages. Large, unweildy and expensive packages are necessary, and above all a great deal of water must be transported. Furthermore, any conceivable automatic metering into a household washing machine is made difficult by the large volume of the required tank.

It is known to use laundry softener concentrates which likewise are dispersions and have a softener content of 15%-30% by weight. However, these known laundry softener concentrates have an exponential increase of viscosity with concentration (Tenside Detergents 18 (1981) 5, pp. 243-246).

The object of the present invention is a laundry softener concentrate which comprises a mixture of one or more laundry softeners, synthetic silicon dioxide and, if necessary, one or more solubilizers for the laundry softener or softeners used.

The laundry softener concentrate of the present invention will contain a sufficient amount of synthetic silicon dioxide whereby the concentrate is in the form of a free-flowing powder. Generally, the concentrate will contain from about 49% to about 75% by weight laundry softener and from about 25% to about 51% by weight synthetic silicon dioxide.

In a particular embodiment of the invention, the laundry softener concentrate can consist of the laundry softener and up to 50% by weight synthetic silicon dioxide alone. In a preferred embodiment, the laundry softener concentrate can contain 30-35% by weight of synthetic silicon dioxide. The content of active material then amounts to up to 70% by weight.

As synthetic silicon dioxides there can be used, as well as oven-dried and milled precipitated silicon dioxides, spray-dried precipitated silicon dioxides, which are either milled or not milled. In addition, silicon dioxides produced by high temperature hydrolysis (pyrogenically produced) can be utilized.

The cationic laundry softeners present in the laundry softener concentrate according to the invention are commercially known products. Preferably cationic nitrogen-containing compounds are used, such as quaternary ammonium compounds and amine salts, which possess one or two straight-chain organic residues containing at least 8 carbon atoms, of which residues advantageously at least one contains 12-22 carbon atoms. There are preferred as laundry softeners in the composition according to the invention, quaternary ammonium compounds having the following formula: ##STR1## wherein R.sup.1 is a long-chain aliphatic residue containing 8-22 carbon atoms or a fatty acid ester group, R.sup.2 is a long-chain aliphatic residue containing 8-22 carbon atoms or an alkyl residue containing 1-6 carbon atoms or an aryl, aryloxy, alkoxy or aralkyl residue containing 6-28 carbon atoms or a fatty acid ester group, R.sup.3 and R.sup.4 are alkyl or hydroxyalkyl residues containing 1-6 carbon atoms or hydroxypolyalkoxyalkyl residues containing 4-20 carbon atoms, and X denotes an anion forming a water-soluble salt, such as, for example, a halide (chloride, bromide, iodide), sulfate, methosulfate, acetate, hydroxide anion, or a similar inorganic solubilizing mono- or dibasic group. The nitrogen can be a ring nitrogen, and the residues R.sup.2 and R.sup.3 can be replaced by a ring formed from 4 or 5 carbon atoms. Particularly good results are obtained with compounds of the given formula which have straight-chain alkyl residues, e.g., alkyl residues, as each of the residues R.sup.1, R.sup.2, R.sup.3 and R.sup.4. Examples of quaternary ammonium compounds which are very suitable as laundry softeners in the laundry softener concentrate according to the invention include: hydrogenated ditalloildimethylammonium chloride; ethoxylated distearyldimethylammonium chloride; dimethyldistearylammonium chloride; trimethylstearylammonium bromide; cetyltrimethylammonium chloride; dicocodimethylammonium chloride; cetylpyridinium chloride; alkyldimethylbenzylammonium chloride containing higher alkyl groups; diisobutyl-phenoxyethyldimethylbenzylammonium chloride; laurylisoquinolinium bromide; distearyldimethylammonium methosulfate; dimethyl-diarchidyl-behenylammonium chloride; di(soya)-dimethylammonium chloride; and stearyldimethylbenzylammonium chloride.

Compounds of the following formula are also usable as laundry softeners: ##STR2## in which R.sup.5 is a long-chain aliphatic residue containing 8-22 carbon atoms, R.sup.6 is an alkyl residue containing 1-6 carbon atoms, R.sup.7 is an alkylamido residue containing 8-22 carbon atoms or a hydroxyalkyl residue containing 2-6 carbon atoms. Examples of these compounds include 2-heptadecyl-1-methyl-1-[(stearylamido)-ethyl]imidazoline methyl sulfate and 2-heptadecyl-1-hydroxyethyl-imidazoline chloride.

Examples of amines which can be used in the form of their water-soluble salts in the laundry softener according to the invention are primary tall oil amine, primary coco amine, primary hydrogenated tall oil amine, tall oil-1,3-propylenediamine, oleyl-1,3-propylenediamine, and coco-1,3-propylenediamine. The water-soluble salts of the amines disclosed above which are particularly suitable are, e.g., the sulfates, the hydrogen sulfates, and the chlorides. By the term "coco" is meant fatty acid groups which are present in the fatty acids of coconut oil. Such acids containing 8-18 carbon atoms per molecule, with the acids containing 12-14 carbon atoms predominating.

The laundry softener concentrates according to the invention can contain up to a total of 35% by weight of a solubilizer or of said solubilizer and water, based on the amount of softener. As solubilizers there can be used isopropanol, ethanol, glycol, benzenesulfonates, toluenesulfonates, xylenesulfonates, or wetting agents such as, e.g., non-ionic surfactants such as nonylphenol ethoxylates, fatty alcohol ethoxylates, and the like.

The laundry softener concentrate according to the invention is a freely-flowing powder. It is stable in storage and, because of its powdery nature, requires only a small packaging space. It can be easily metered, and can if desired or necessary be combined with detergent.

1. The laundry softener REWOQUAT.RTM. CR 3099 (100%) (difatty acid ester dimethylammonium methosulfate) was heated to 60.degree. C. and mixed with 31% by weight of the silicon dioxide Sipernat 22 S. The laundry softener concentrate obtained as a flowable powder.

2. The 75% laundry softener dispersion REWOQUAT.RTM. W 7500 (75% quaternary imidazolinium-dialkyl compound with 25% isopropanol) was mixed with 34% by weight Sipernat 22. The laundry softener concentrate obtained was a flowable powder.

3. The 75% laundry softener dispersion REWOQUAT.RTM. W 7500 H was first melted and then mixed with 35% by weight Sipernat 50. The laundry softener concentrate obtained was a flowable powder.

4. The 75% laundry softener dispersion Prapagen WK (distearyl dimethylammonium chloride) was mixed with 32% Sipernat 50 S. The laundry softener concentrate obtained was a flowable powder.

The silicon dioxide Sipernat 22 used is a precipitated and spray-dried silicon dioxide. It has the following physical and chemical characteristics:

The silicon dioxide Sipernat 22 S used is a spray-dried and milled precipitated silicon dioxide with the following physical and chemical characteristics:

The silicon dioxides Sipernat 50 and 50S used are spray-dried precipitated silicon dioxides with the following physical and chemical characteristics: