DE2355025C3 - Process for the production of waterproof leather - Google Patents

Description

Chain lengths C ₁ to C ₈ . The procedure has the usual advantages of

5. The method according to claim 1 and 2, characterized in 30 Licker process from aqueous liquor, namely characterized in that component (B) tetra-avoidance of large amounts of low-boiling organihydrofurfuryl alcohol is. harsh solvents and elimination of pre-drying

6. The method according to claim 1 to 5, characterized in the tanned leather. In contrast to the known characterized in that a mixture is used. Processes are highly dynamic leathers obtained with a ratio of component (A) to 35 water resistance, with difficulties such as Component (B) from 9: 1 to 1: 9, preferably by superficial deposition of the impregnation 1: 1 up to 2: 1. by means of or staining or hard and unsightly

7. The method according to claim 1 to 6, thereby creating a pleasant grip, omitted,
characterized in that one in the aqueous liquor as component (A) are acidic citric acids for complete neutralization of the acidic ester of higher fatty alcohols of chain lengths C _n to citric acid ester insufficient amount of ammonium C ₂₂ , preferably Ci ₂ to C ₁₈ , into consideration. Preference is given to using niak as well. the esters of straight-chain unsaturated fatty

8. The method according to claim 1 to 7, characterized in alcohols and branched-chain saturated or unmarked, that chrome leather with the aqueous saturated fatty alcohols, z. B. Citric acid mono liquors be treated. 45 oleyl ester or citric acid monoisooctadecyl ester.

As the component (B) are organic solvents having a boiling point above 100 ° C, preferably above 130 ⁰ C, on the one hand with water

are wholly or partially miscible, and on the other hand

50 dissolve the acidic citric acid ester in every ratio. Examples of such solvents are the alkanediols of chain lengths C ₂ to C ₆ , such as ethanediol, 1,2- or 1,3-propanediol, 1,3- or 1,4-butanediol,

It is known that dry 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2-propylprofter Leather with an organic solution of acidic 55 pandiol-1,3, 2-methyl-2,4-pentanediol, also the ent fatty alcohol citric acid esters good dynamic water-speaking monoalkyl ethers with lower alcohols can achieve strengths. The practical users of chain lengths C, to C ", such as methanol, ethanol, However, the need to use large amounts of propanol, isopropanol, or butano !, as well as tetra quantities organic solvent, e.g. B. chlorinated hydrofurfuryl alcohol.

Hydrocarbons or gasoline, to use, quite 60 The quantitative ratio of component (A) to considerably more difficult. The use of such component (B) should be 9: 1 to 1: 9, preferably 1: 1 Solvent not only requires significant labor to be 2: 1.

Protective measures, but also easily leads to degradation. The used to impregnate the leather

Divorce or discoloration of the impregnated liquor liquor is caused by stirring in a solution of the Leather, since the solvents on the surface dissolve in the corresponding solution vapor and some of the dissolved dyes medium prepared in water in the usual way. the and transport tannins to the surface. Emulsification is made even easier when you use the In addition, the aqueous phase required before the impregnation before or during the emulsification process

Ganges had an insufficient amount of acidic citric acid ester to completely neutralize the and when tested in the Bally penetrometer, a very unfavorable water penetration value of ammonia added. You get a sufficient 3 minutes,
stable liquor, which is used in the usual way for licking, for example chrome-tanned or vegetable-based 5 B e ι s ρ ι e 1 2
synthetically tanned leather is used. The vegetable-synthetic retanned chromium content of acidic citric acid ester in the leather upper was rinsed, as described in Example 1, new liquor should be 3 to 8 percent by weight, based on the tralized, and rinsed in 200% water
Folding weight of the leather.

The quality of the Imprägniereffektes depends largely io ⁵ ° ^{/ o} Crtronensäure-monoalkcmylester

on the chosen solvent. This erlcich-, - "," r KettenlangenC ₁ to C ₁ ,,

not only the penetration of the citric acid ester Hl 6 klykolmonoathylather,

in the leather, but at the same time it also increases the ^{1) 25 / o ammonia} (25 ° / o «g)

Softness and smoothness of the leather as it tumbled bsi 60 minutes at 50 ⁰ C. In the case of the citric acid

the usual dry process because of its high 15 ester it is the esterification product of

Boiling point does not evaporate. The excellent citric acid with about 1 mole of a technical

dyDunic water resistance is based on the formation of a mixture of higher unsaturated alcohols, which in the

a viscous water-in-oil emulsion obtained as a residue on distillation of oleyl alcohol

Ingress of water clogs the pores of the leather and becomes (SZ: 0.5; JZ: 80; OHZ: 80 to 100).

prevents the water from penetrating deeper. _i0 The leather was soft and supple; in the Bally

A particular advantage of the inventive penetrometer was the excellent water permeability

driving consists in the firm binding of the impregnation step time of 125 minutes,
by means of the leather, especially chrome leather.

This is shown by the fact that the impregnating agent in the range of 13

In contrast to common liquor oils due to dichloro 25

methane (according to DIN 53 306) practically no more vegetable-synthetic retanned chrome leather

can be extracted. (Gap thickness 2 mm) was, as described in example 1

According to the claimed process, leathers are treated. Only in place of the glycol mono with good softness and suppleness and excellent ethyl ether were the following solvents with excellent dynamic water resistance, so used. When testing for dynamic water, that additions of customary fatliquoring agents were in the leak resistance in the Bally penetrometer, the subsequent liquor was generally unnecessary. A post-treatment is given the following water penetration times:
with retanning agents or dg'i. can in the usual way
be performed.

35 Example 1

Vegetable--synthetically retanned chrome leather (split thickness 1.1 mm) was purged for 20 minutes at 30 ⁰ C and then bicarbonate in 150% float with 1.0% sodium 40 45 minutes at 35 ⁰ C and then neutralized for 20 minutes at 35 ° C flushed.

The leather pretreated in this way was in 200% water with

5.00% citric acid monooleyl ester, ⁴⁵

3.35% glycol monoethyl ether, 1.25% ammonia (25%)

Fulled for 60 minutes at 50 ^° C. After draining

the liquor was in 200% water with 0.5% ant 50

acidified and with the addition of 2% chromium. For comparison, the leather was made with 5% pure fat

tanning agent (33% basicity, 26% Cr ₂ O ₃ ) licked with a commercially available sulphated semen oil for 60 minutes.

40 ° C. The leathers were drummed over night

Bock and received after the pasting process.

^ne '· 55 Example4

The leather obtained afterwards was soft and supple and had an excellent dynamic retanned chrome leather (gap thickness 2 mm) WUR water resistance, How: the test in the Bally Penetrode is processed as described in Example 1. As a soldering meter revealed. The passage of water took place after this solvent was used as glycol monoethyl ether Test procedure only after 73 minutes. 60 impregnating substance citric acid monoisoocta-

For comparison, a predecyl ester was used in the same way. Examination of the finished leather in Treated leather in a liquor (200%) with a Bally penetrometer gave a water penetration time

5.00% citric acid monooleyl ester, ^{from 50 minutes}

1.25% ammonia (25 ° / _o solution) B ρ ice ie 1 5

Fulled for 60 minutes at 50 ° C and vegetable-synthetic retanned chrome leather as described

was completed, as described in Example 1, with a

leather obtained afterwards was flat and tinny, a mixture of citric acid monooleyl ester and glycol

Kp. water passes through ⁰ C (Min.) Tetrahydrofurfuryl alcohol 178 170 Ethanediol 197 42 1,2 propanediol 188 109 1,4-butanediol 235 150 1,5-pentanediol 238 128 2 methyl 2,4-pentanediol 199 64 Glycol monomethyl ether 125 48 Glycol monobuty lather 171 85 1,2-propanediol mono- 174 75 buty lather Isopropanol 82 4th

monoethyl ether leaked. For comparison, a Corresponding chrome leather sample leaked with a commercially available sulfated sperm oil, whereby likewise 5% pure fat was used on the shaved weight of the leather. After finishing the leather the samples were chipped and extracted in the usual way for fat determination with dichloromethane. The following amounts of extract were obtained based on the leather:

Impregnated according to Example 5

Leather 1.5% extract

Licked with sulfated semen oil-

tes leather 6.4% extract

Blank value of the unlicked

Chrome leather (natural fat content) ... 1.3% extract

All values given relate to anhydrous leather.

Claims (4)

agile drying of the leather an additional patent claim: work process and considerable additional costs. Attempts have therefore already been made to the water-soluble 1. Process for the production of waterproof leather to use salts of the corresponding citric acid esters in water through Lickera with an aqueous liquor under Veriger liquor. However, using citric acid esters of higher fats, this process does not readily lead to useful results. For example, alcohols with a hydrocarbon chain with 12 can occur on chrome leather because of the up to 22 carbon atoms as an impregnating agent, thereby acidic reaction to form superficial deposits, characterized by the fact that the leakage with the neutralized water-soluble citric acid ester is a mixture of (A) io emulsified in water . Leathers impregnated in this way dry hard and have an acidic citric acid ester of the higher fat sheet metal and have insufficient water alcohols and (B) a wholly or partially firm. Neutralization of chrome leather water-soluble organic solvent for the entire cross section of time, although could facilitate unities citric acid ester with a boiling point of penetration of the impregnating agent, however, is carried out above 100 ⁰ C. 15 not practically feasible because it also means 2. The method according to claim 1, characterized in that the leather quality suffers. draws that component (A) is an acidic object of the invention is now a process for Citric acid ester of a straight-chain unsaturated production of waterproof leather by licking with a th fatty alcohol or a branched-chain, aqueous liquor using citric acid-saturated or unsaturated fatty alcohol of the ao esters of higher fatty alcohols with a hydrocarbon chain length of C ₁ J to C ₁₈ . chain with 12 to 22 carbon atoms as impregnation 3. The method according to claim 1 and 2, characterized in that the liquor is characterized in that component (B) is a with a mixture of (A) alkanediol of chain lengths C ₂ to C ₆ emulsified in water. an acidic citric acid ester of the higher fatty 4. The method according to claim 1 and 2, characterized in that 15 alcohols and (B) one wholly or partially in water, that component (B) is a soluble organic solvent for the citric monoalkyl ether of an alkanediol of the chain acid ester with a boiling point of above 100 ° C length C ₂ to C ₄ with a lower alcohol that carries out.