DE1261269B - Process for greasing leather - Google Patents

Description

Process for greasing leather Greasing leather is an important one Part of leather manufacturing. Suppleness, resistance and durability of the individual types of leather are largely determined by the type of fatliquor used certainly. For the fatliquoring of mineral-> combined- or vegetable-tanned products using the liquor method Today, leather is available in a number of different fatliquoring agents, such as B. sulfated Foot oil, sulfated oil, sulfated sperm oil products, or sulfated fatliquoring agents available on a hydrocarbon basis. The products mentioned are added to Group of anion-active fatty agents, as the active ingredient in aqueous Solution is present in the anion. However, aids are also used today for which the emulsifier component, which is decisive for the effect, reacts as a cation. Belong here z. B. quaternary ammonium, phosphonium or sulfonium compounds or primary, secondary or tertiary amines. But also non-ionic fatliquoring agents, which by Emulsification of an untreated oil with non-ionic condensation products, such as you z. B. by etherification or esterification of suitable bodies with polyalcohols, Alkylene oxide or alkylene imine obtained are used for certain purposes.

The drying of leather after the pasting process is based on Art the fatliquor used has special requirements. Products or Product mixtures are required which, in addition to sufficient grease, also have a cause sufficient surface oiling of the leather, so that the glue drying The adhesives used do not penetrate the inside of the leather, which prevents the Leather on the glass plates can be made extremely difficult. Since the Fettungseffeki very much on the charge of the leather, which is caused by the tanning and retanning agents used is decisively determined, is dependent, you get with a product combination, which z. B. on a leather pretanned with chrome and vegetable retanned has proven its worth on leather that has been chrome-pretanned and with synthetic or resin tanning agents retanned does not give the same good results. The greasing of combined tanned leather types, especially upper leather, is therefore still a non problem solved completely satisfactorily. Difficulties also exist in that in the case of very soft leather types, the amount of fat cannot be increased indefinitely, without getting to loose-grain and thus inferior leather. On a mechanical one Post-processing of the leather by one or two staking processes after the For the aforementioned reason, Leders has not yet been able to be dispensed with.

The invention accordingly provides a process for the fatliquoring of vegetable, mineral or combined tanned leather in the lick process, in which this leather is treated with a mixture of at least one ester oil and mineral oil and soluble salts of a sulfated ester oil and an oxethylated fatty amine salt of the general formula where: R '= organic radical with at least 8 carbon atoms, R "= H or organic radical with at most 7 carbon atoms, X = anion of an inorganic or lower organic acid, m + n = 4 to 40, are treated.

The treatment according to the invention imparts to the leather without further additives so high a softness with sufficient strength that on the otherwise usual stollen process can be waived in whole or in part. Those given in the examples below and similar mixtures used are largely independent of the charge of the Leather surface and can therefore be used for very differently tanned products, namely vegetable, Mineral or combined tanned leather can be used with success.

The mixtures used according to the invention are preferred at 40 applied in an amount up to 70 ° C; which corresponds to 2 to 15 ° 10, based on the folded weight. In general, the intensity is the Surface lubrication, independent from the preparatory work, sufficient for drying after the pasting process. However, there is the possibility that towards the end of the licking process after about 40 Minutes of the liquor liquor, table salt is added in an amount that is 0.5 to 1.5%, based on the folded weight.

Ester oils suitable for the process are preferably those in nature occurring, namely sperm oil or other liquid waxes, as well as esterification products unsaturated fatty acids with alcohols, such as methanol, butanol, octanol or lauric alcohol, or other unsaturated fatty acid esters of monohydric alcohols. The sulphonation products of the ester oils mentioned, which are required for the process, are obtained in a known manner Way from the ester oils by the action of concentrated sulfuric acid, oleum or other sulphurizing agents and neutralization with alkalis, ammonia or low molecular weight amines, optionally after prior, simultaneous or subsequent Wash with water or saline solutions. The oxethylated fatty amine salts of the specified The formula is also obtained in a known manner in two stages. By exposure from ethylene oxide to primary amines in the first stage, the oxethylates are obtained. In the second stage, these are either mixed with hydrochloric acid, sulfuric acid, phosphoric acid, Formic acid, acetic acid, other inorganic or lower organic acids neutralized or z. B. quaternized with alkyl halides or sulfates. Preferred Dimethyl sulfate, chloromethyl, bromoethyl, benzyl chloride or the like are suitable for this.

An advantage of the mixtures used according to the invention is that they in contrast to other leather fatliquors with a relatively low water content can be produced. These mixtures are therefore over a longer period of time stable and show no tendency to separate during storage. Also the The ability to emulsify and the greasing properties are enhanced by a long storage time not affected. The fat absorption is, regardless of the tanning of the leather, almost completely.

In the following, the invention will be applied to some specific blends explained: The amounts given in the examples are, insofar as they relate to the Mixtures refer to parts by weight.

Example 1 It is initially a mixture of 60 parts of alkali salt a sulphated cod liver oil (fat content 75%; degree of sulphation 8 to 10%) and 6 parts of a condensate made from oleylamine and 15 moles of ethylene oxide and neutralized with formic acid or 85% phosphoric acid. After intimate Mix 10 parts of a low to the initially cloudy mixture in sequence viscous mineral oil, 4 parts of sperm oil and 20 parts of fish oil have been added. To the mixing gave a clear, viscous oil according to the invention can be used for fatliquoring combined tanned upper leather as follows: Material: Full chrome tanned, folded cowhide, thickness 1.4 to 1.5 mm. Wash With rinsing lid, 35 ° C, 5 minutes. Neutralization 200% water, 35 ° C, 4% of a synthetic Retanning agent with low astringency for chrome leather, 35 minutes. Rinse: With Rinsing lid, 30 ° C, 5 minutes. Fatliquoring and retanning: 200% water, 60 ° C, 7.5% der specified fat mixture, 40 minutes. Postscript: 8% liquid chestnut extract, 20 ° B6, added in three portions, 15 minutes apart. Further running time: 15 Minutes.

Leather on the buck overnight, drying after the pasting process, for example Store in a cool room for 3 days, sand the grain side of the leather with sandpaper No. 320. A stud of the leather is not necessary. That in the specified way Treated leather is sufficiently soft without further treatment and has a firm feel Scars and can be trimmed in the usual way. Example 2 material: full Vegetable tanned goatskin, suitable for lining leather, thickness approx. 0.8 mm.

The lining leather, which is fully vegetable tanned in the usual way, becomes treated further as follows.

Rinse 30 ° C, 10 minutes.

Retanning and fatliquoring according to the invention: 200% water, 45 ° C, 3% one synthetic full tanning agent, 15 minutes.

Addition 5.2% of the fat mixture given in Example 1, 40 minutes, Addition 1.2% table salt, 10 minutes.

Leather on the go, drying after the pasting process, storing for a few days in a cool room, sanding the carrion side with sandpaper No. 180. This type of leather does not require any further mechanical finishing to achieve greater softness.

EXAMPLE 3 First a mixture of 40 parts of an alkali salt of a sulfated sperm oil (degree of sulfation 28 to 30%; fat content 75%) and 10 parts of a condensate of oleylamine and 20 mol of ethylene oxide was prepared and neutralized with acetic acid. Another 25 parts of sperm oil and 25 parts of a medium viscosity mineral oil have been added to the mixture. A thick UI was obtained after stirring well. The specified mixture can be used according to the invention for the fatliquoring of soft, combined tanned leather as follows: Material Fully chrome-tanned, folded cowhide of the weight class 20 to 24 kg, thickness 1.5 mm. The pH value of the leather cross-section should be around 4.0.

Rinse with rinsing lid, 30 ° C, 10 minutes. Neutralization and retanning: 2500/0 water, 45'C, 2% of a polyphosphate, described in the journal »Das Leder ", 1952, p. 126, last paragraph and p. 127, 40 minutes.

Postscript 40.1o of a synthetic retanning agent with low astringency for chrome leather, 5 minutes. Postscript: 20/0 of a resin tanning agent on the basis of dicyandiamide and formaldehyde, described in U.S. Patent 2,567,238, 40 minutes. Liquor pH about 5.6.

Leather cross-section against bromocresol green.

Rinse with rinsing lid at 60 ° C, 10 minutes. Greasing 7.8% of the specified Fat mixture, 45 minutes. Follow-up: 0.5% table salt, 5 minutes.

Leather on the buck for 24 hours, drying after the pasting process, some Store for days in a cool room, sand the flesh side with sandpaper No. 320 and then prepare. A mechanical post-processing for the aforementioned leather type it is also not necessary to achieve greater softness. The leather meets the technical requirements in terms of softness and grain pattern.

Example 4 10 parts of a condensate of oleylamine and 20 mol of ethylene oxide, which has been made quaternary with dimethyl sulfate is with good stirring with 20 parts of sperm oil and 20 parts of a medium-viscosity mineral oil have been mixed. Then 50 parts of the alkali salt of a sulfated sperm oil (degree of sulfation 30%; Fat content 75%). The specified mixture can according to the invention Combined tanned leather, as described in Example 3, is used for fatliquoring will.

The progress achieved according to the invention is clearly shown when the method according to the invention with the method of the German patent specification 738 901 compares the use of fatty amine salts, especially the acetates or formates, described after or before the treatment of the leather finitely sulfonated Ulen is. In contrast to the subject matter of the invention, the known method has two baths and therefore more cumbersome. In addition, in this way of working it is very difficult to find the right ratio of fatty amine salts and sulfonates on the leather, since the aim is obviously to remove the sulfonated ones on the leather Ule to be converted into water-insoluble fatty amine salts. But this is only for one very specific mixing ratio possible because of excesses of one or the other Lead component to peptization.

The subject matter of the invention also has advantages over German patent specification 742 670, which describes the use of amine salts and quaternary fatty ammonium compounds to make leather waterproof or water-repellent. According to the known process, the leather is greased with a sulfonated 101 before or after the amine treatment. In principle, it is therefore the same process as in the first-mentioned German patent 738 901.

The German patent specification 863 243 describes a method for lubricating greasing. However, this method is fundamentally different from the method of the present invention, in which a vegetable, mineral or combined tanned leather according to the lick process, d. H. So is greased in aqueous liquor, different. .

According to the process of this patent, water-insoluble * oils on an animal, vegetable or synthetic basis together with higher esters Fatty acids or higher alcohols containing at least two residues of such fatty acids or contain alcohols and at least one basic nitrogen atom. Admittedly, according to this patent, the use of fatty acid esters with at least a basic nitrogen atom lead to a softer leather that is more pleasant to the touch, which at the same time has a lower water absorption, but it is the fatty acid esters listed in this patent are without exception water-insoluble Connections, as is understandable with greasing. On the other hand is the mixture of a fat combination used in the process according to the invention, consisting of an ester oil and mineral oil as well as soluble salts of a sulfated one Ester oil and an oxethylated fatty amine salt, soluble or emulsifiable in water.

Claims (2)

Claims: 1. A method for fatliquoring leather using salts of fatty amines or ammonium compounds, dadurchgekenn -z eichnet that vegetable, mineral or combined tanned leather in the Licker process with a mixture of at least one ester oil, mineral oil, soluble salts of sulfated ester oils and an oxethylated fatty amine salt of the general formula in which R 'is an organic radical with at least 8 carbon atoms, R "is hydrogen or an organic radical with at most 7 carbon atoms, X is an anion of an inorganic or lower organic acid and m + n = 4 to 40. 2. The method according to claim 1, characterized in that the mixture is used at temperatures between 40 and 70 ° C in amounts of 2 to 15 percent by weight, based on the shaved weight. Considered publications: German Patent Nos. 738901, 742670, 863243.