SE430793B - PROCEDURE FOR FAT LICKER TREATMENT OF LEADER, AND MEASURED PROCEDURE TREATED LEADER - Google Patents

Description

7s1ani4s4-e4 Sulfonated mineral, vegetable or animal oils are most often used as fatty substances, often in admixture with non-sulphonated oils. Examples of such oils are turquoise oil, sulfonated tranol oil, sulfonated sperm oil, clove oil, sulfonated fatty alcohols and also partially chlorinated, sulfonated or oxidized fats and fatty oils.

To carry out the fat lick treatment, the leather is brought into contact at approximately 30 - 60 ° C with 100 - 200% by weight of water containing 5 - 10% by weight of fat, in which case the percentage is calculated on the weight of the leather. The liqueur treatment is continued until the maximum amount of fat is taken up by the leather, which generally takes about 40-60 minutes. French patent 647 456 proposes the use of phosphatides in the fat liqueur treatment due to their emulsifying properties and it is said that the phosphatides would contribute to the penetration of the fat into the leather and increase its fat absorption capacity.

In practice, however, the use of phosphatides in the fat lick treatment is limited due to the fact that they are absorbed in insufficient amount in the leather and give insufficient fat in the interior of the leather. Such insufficient greasing makes the leather too hard and stiff. In addition, the poor fat absorption means that a high residual fat content is present in the liquid * and this leads to large fat losses.

It has now been found that hydroxylated phosphatides are unusually suitable for use as a fatty substance in the fatty liquids for greasing the leather. In contrast to unmodified phosphatides, the hydroxylated phosphatides penetrate the entire thickness of the leather and are almost completely taken up by the leather from the grease licking liquid, making the residual content in the licking ring bath very low. The present invention thus relates to a process for fat-licking treatment of tanned leather with an aqueous emulsion of a fatty substance comprising a phosphatide, the process being characterized in that a hydroxylated phosphatide is used as phosphatide. Preferably the fatty substance comprises 30 - 100% by weight, most preferably 70 - 100% by weight of the hydroxylated phosphatide.

Preferably, a mixture of hydroxylated phosphatides obtained by hydroxylation of a vegetable phosphatide mixture, separated from a vegetable oil such as soybean oil, peanut oil, rapeseed oil, cottonseed oil, cottonseed oil, etc., by a suitable slurry ; for example by treating the oil with water or steam.

Soybean phosphatides in particular are preferred because they are widely available.

In addition, phosphatides modified before or after the hydroxylation can be used in other ways. Particularly useful in this regard are phosphatides which, before or after the hydroxylation, have been subjected to partial hydrolysis by treatment with an acid, a base or an enzyme, such as phospholipase A. Preferably, hydroxylated phosphatides which have been hydroxylated until the iodine value is reduced by 5-25 percent are used. . Phosphatide fractions obtained by fractionation of crude or modified phosphatide mixtures with a solvent or a mixture of solvents can also be used as starting materials for the hydroxylation; the hydroxylated phosphatide mixture may also be fractionated and one or both of the fractions may be used as a greasing agent according to the invention. Alternatively, the fatty substance may contain soybean oil. 7a1 fi4 than-4 For use with chrome-tanned leather, it is desirable that the greasing composition according to the invention should contain a substance which increases its chrome resistance. As such substances, ethoxylated alkylphenols can be used such as ethoxylated nonylphenol, which is available under the trademark Arkopal - N 150 B 'from Tarbwerke Hoechst, Germany. in use, the amount of the chromium resistance-increasing agent added is usually about 3 to 15% by weight, preferably 3 to 10 percent and most preferably about 4 to 26 percent, based on the total fat mixture. The salt stability of the greasing mixture is also increased by such means. An emulsifier may also be added.

Process for hydroxylating phosphatides is described in U.S. Patents 2,445,948 and 2,629,662. In said process, the phosphatides are reacted with an oxidizing agent, preferably hydrogen peroxide, optionally in the presence of an acid such as acetic acid, but preferably lactic acid, which serves as a catalyst; Through the reaction, the double bonds in the fatty acid chains of the phosphatides are converted to glycol hydroxyl groups, some of which can be esterified with acyl groups. According to this process, the iodine content of the phosphatides, which for soybean phosphatides is originally about 95 - 10 0, is reduced by 5 -225 percent.

The phosphatide greases according to the invention are used in essentially the same way as the greasers usually used in grease licking treatment of leather, ie. in a rotating container, the leather is contacted at 40 - 60 ° C with 100 - 200% by weight of water containing 5 - 10% by weight of the phosphatide degreaser until the desired degree of degreasing is reached.

The greasing agent according to the invention can be used for fat-licking treatment of all kinds of leather, such as buckskin (deer leather), split upper leather (split upper leather), vegetable tanned leather, grained leather, suede etc. 7810454-4 The invention is further illustrated by the following examples wherein the temperature refers to degrees Celsius.

Example A number of chrome-tanned "wet-blue" cowhides were shaved to a thickness of 1.6 mm. The skins contained 5.9 percent Cr2O3, calculated on the dry matter and their pH was 3.3. The skins are transferred to a rotating container and 200% by weight of water at 55 ° C is added. Then 2% by weight, calculated on the skin, Tanigan PC R (a tanning agent from Bayer, Germany) was added. After 10 minutes, 0.8% by weight of Luganilbraun NT R (a dye from BASF, Germany) dissolved in 15 times its weight of water, after which, after a further 10 minutes, 6.3% by weight of a hydroxylated soybean phosphatide mixture (iodine value 87.6 and containing 5% by weight of Arkopal-N150 \ EÖ an ethoxylated nonylphenol from Farbwerke Hoechst, Germany), dispersed in 7 times its weight of water. The bath temperature was 38 ° C and the pH was 4.72 After 20 minutes a mixture of 2% by weight of wattle, 2% by weight of Tanigan PR (a tanning agent from Bayer, Germany) and 2% by weight of Retingan R7 was added for 15 minutes 0.15% by weight formic acid and after exterior (a tanning agent from Bayer, Germany) to the bath. at night. The skins were then pressed, vacuum dried at 85 ° C for 2.5 minutes and post-dried at 25-30 ° C for 1.5 hours. After a few days, the skins were stretched (staked).

After the greasing step, the liquid contained only 0.95 g / l of the phosphatides. Considering that 50 percent of the 200 percent added water is absorbed by the skins, this means that 98 percent of the phosphatides are absorbed by the leather. The greased skins contained 8.5% by weight of the phosphatides, calculated on the dry leather (determined by extraction with methylene chloride).

The physical properties of the greased skins corresponded to demands for good quality leather.

Claims (10)

1. 7ïas1§oï§ss4- = 4g é l '_ PATENT CLAIMS àörfaranae for greasy treatment of tannery: laden with a water emulsion of a fatty substance comprising a phosphatide, k ä-n ne t'e ck “na = t' d-ä rav , that a hydroxylated phosphatide was used as the phosphatide. 2. A process according to claim 1, characterized in that the fatty substance comprises 30-100% by weight of the hydroxylated phosphatide. 3. A process according to claim 1 or 2, characterized in that a hydroxylated vegetable phosphatide mixture is used. 4. Process according to claims 1 - 3, characterized in that hydroxylated soybean phosphatides "are used. 5. A process according to claims 1-4, characterized in that a phosphatide is used which has been hydroxylated until the iodine value has been reduced by 5-25 percent. Process according to one of Claims 1 to 5, characterized in that a partially hydrolyzed hydroxylated phosphatide is used. 7. A method according to any one of claims 1 to 6, characterized in that an additional fatty oil and / or sulfonated oil such as clove oil, sperm oil or sulfonated sperm oil is used in the liqueur treatment bath. 8. A process according to claim 7, characterized in that soybean oil is used as the fatty oil, A method according to any one of claims 1 - R, k 3 ß ~ n e t k c n a t 8 ”r af that the liqueur treatment bathct contains an emulsifier. Leather, characterized in that it has been treated by the method according to any one of claims 1 to 9. '7ë3-ï1f0-'f4ï54- 4' 'SUMMARY Hydroxylated phosphatides -used-as a component in or as the only greasing agent-in the fat-licking treatment liquid. The hydroxylated phosphatide: penetrates the entire thickness of the leather in contrast to unmodified phosphatides, thus giving the leather suppleness and softness. The residual fat content in the liqueur treatment bath is low.