US1992131A - Leather dressing composition - Google Patents

Description

Patented Feb. 19, 1935 LEATHER DRESSING CODIPOSITION Emil Sajak, Dresden, Germany No Drawing. Application September 25, 1930,

Serial No. 484,466. 1929 In Germany August 31,

8 Claims. (01. 149-6) This invention relates to a leather-dressing composition, applicable to both ordinary or oak tanned and chrome tanned leathers, for example for leather wearing apparel, upholstery leather,

footwear, and other forms in which leather is employed, the object of the present invention 'beingto render the leather soft, pliable, tough and 1 waterproof.

By liquid wax" as used herein are meant oer- 10 tain substances, neither oils nor fats which have certain physical and chemical properties. These substances, so far as now known are the so called sperm oil and the bottle-nosed whale oil the use of oil in these terms being a misnomer. These two in smell, taste and color reactions resemble .the well known train oils but have a specific gravity of only 0.875 to 0.884 and are of astonishingly low viscosity less influenced by temperature changes than the train oils. The waxy nature shows in the degree of saponification and they yield only 60 to 65 percent of fatty acids. They are highly resistant to oxidization and the iodine figure is only 80 to 8'7.

Waxes have already been used for leather- 85 dressing, solid waxes being only used in conjunction with fats or oils or when dissolved in benzine or turpentine, while sperm oil has been used in tanneries for fat-liquoring and greasing the hides. Liquid waxes alone, such as the latter, penetrate through the leather and make itoily to the touch. .Solutions of solid waxes in benzine, turpentine or the like are not stable, because the solvent evaporates again, causing the waxes to become hard and to impart brittleness to the leather. When combined withoils and fats they can only be employed inefficiently in small amounts, consequently the glycerides which form the chief constituents are easily decomposed and the leather is thus not permanently protected.

The present invention consists in the employment of a solution or mixture of solid waxes in liquid waxes to which animal or vegetable fats or oils, preferably castor oil, can be added. The liquid waxes w ch may be employed may be, for example, d6glings oil (hyperoodon rostratus' oil), or sperm oil. These oils are of animal origin and although termedoils they really belong to the wax class, because they contain either none or very little glycerine, but in place thereof have about 32 to 43% of a monovalent high molecular alcohol, viz. cetyl alcohol, which contrary to glycerine is insoluble in water. The liquid waxes have a very low specific gravity (0.8754384), and very low viscosity, which is less affected by variations in temperature than that of the fatty adapted for preserving leather and for rendering it soft, pliable and waterproof. Such a solutlOIl is also particularly suitable, especially for footwear and other wearing apparel, owing to its low heat conductivity. 10

If castor oil is added to such a solution, the further advantage is obtained that the properties favourable to the preservation of leather, viz. durability, low acidvcontent and water repellent action are retained. The undesirable 15 properties, viz. high viscosity and tendency to "gum and to form a tough adhesive gummy coating, are eliminated.

Castor oil has a favourable action on the waxes, particularly on liquid waxes, by raising the low viscosity and enabling the waxes to adhere more firmly to the leather.

The improved leather-dressing composition meets all the requirements of a satisfactory dressing composition. The improved composition ren- 25 ders the leather tough, soft and-pliable and protects it in its chemical state, is. against the oxidizing action of the atmosphere and against the de-tanning effect of acids or alkalis; it also makes the leather waterproof, causes it to retain its ventilating properties and protects it from premature mechanical wear; it also makes it more effective as a heat insulator. It contains no readily volatile constituents, which by evaporation would permitsub'st'ances dissolved therein to. re- 35 turn to their previous hard consistency and thus render the leather brittle. It also contains no solvents which would, for example, dissolve the pitch usedin closing the seams in footwear, as well as also containing no substances which tend to absorb water. It remains unchanged and of the same consistency in the leather and excellently protects the leather, each fibre of the leather being enveloped in a wax protective coating. Leather which is impregnated with this dressing composition does not become hard, even when left long in water. On the other hand, leather which has become hard by lying in water, can be made soft again by treatment with this dressing composition. One of its particular advantages is that it protects the leather against the action of caustic alkalis. .As waxes are not decomposed at ordinary temperatures by caustic alkalis and the fibres of the leather treated with this dressing composition are enveloped in a wax coating, the

alkalis are unable to reach the substance of the leather and to decompose it. This is of great importance to gardeners and agricultural workers, who have to work with artificial manures containing lime and also builders workmen who handle lime.

The following are examples of the improved dressing compositionz- 2.5 parts by weight each of bees wax and spermaceti in 95 parts of sperm oil may be employed,

for example, for snow boots, motor leathers and leather coats.

5 parts each of bees Wax and spermaceti in 90 parts of sperm oil may be used as a thicker oil for stronger boots, such as fishing boots and workmenis boots.

7.5 parts each of bees wax andspermaceti in 85 parts of sperm oil in the form of a cream may be used in summer and for the fishing and building trades.

2.5 parts each of bees wax and spermaceti in 50 parts of sperm oil and parts of castor oil forms a viscous liquid dressing for snow boots and leather coats.

5 parts each of bees wax and spermaceti in parts of sperm oil and 40 parts of castor oil, 20 parts of which may be replaced by animal fats, can be employed in the form of a cream in trades which have to work in water and wet grass, such as anglers, hunters, fishers and agricultural workers.

A solution of about 15% by weight of bees wax' and 15% of carnauba wax in liquid wax is exceptionally good for rendering hard leather waterproof, such as sole leather and leather belting. It renders it elastic but not so soft that it is not suitable for the purpose for which it is to be employed as sole leather or leather belting.

I claim:

1. A leather-dressing composition comprising a mixture of solid waxes in sperm oil and castor oil.

2. A leather-dressing composition comprising a mixture of solid waxes in approximately equal parts of sperm oil and castor oil.

3. A leather-dressing composition comprising a mixture of solid waxes, sperm oil, castor oil and animal fat.

4. A leather-dressing oompositon comprising a mixture of solid waxes, sperm oil, castor oil and animal fat, the castor oil and animal fat being EMIL SAJAK.