Process for softening/stuffing leather and fur skins

Details Process for softening/stuffing leather and fur skins Process for softening/stuffing leather and fur skins

1995-06-09

1996-11-19

Green, Anthony

Compositions

Leather or fur treating

8 941R, 8 9414, 8 9418, 8 9421, 8 9422, C14C 900, C14C 1100

Patent

active

055759394

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to a process for softening/fat liquoring and greasing leathers and fur skins with an aqueous dispersion of a copolymer obtainable by acid and/or maleic acid with C.sub.12 -C.sub.30 alcohols and
saturated monomers which are copolymerizable with a) and b), with the proviso that a)+b)+c)=100, polymerization with monovalent alcohols comprising at least one ether functionality, whereby the molar ratio of anhydride to alcohol is of the order of 1:0.5 to 1:2, preferably 1:0.7 to 1:1.5 so that the amount of hydrophilic units of the resultant polymer body is larger than 50%-wt. and groups in the polymer and manufacturing a flowable dispersion having an active substance content of at least 40%-wt., preferably at least 50%-wt.
In the leather industry, fat liquors and greases are frequently used to produce soft, supple leather types. For the most part, these are natural fats, oils and waxes which are partly rendered hydrophilic by a suitable chemical treatment, for example by sulfatation or sulfitation, so that they can be used in aqueous liquor on the one hand, and, on the other hand, an improved bond to the fibrous structure of the leather is achieved. The disadvantage of said fat liquors is the fact that they can be removed from the fibrous network by washing or, in particular, during usual dry cleaning with halogenated hydrocarbons, which leads to an embrittlement of the leather. A similar effect may occur when the fat liquors are removed from the leather by migration, in particular at elevated temperatures caused by intensive solar radiation. In the special case of seat covers in vehicles, this process results in the so-called "fogging"-behavior since the dissolved low-molecular constituents of the leather deposit as foggy, smeary films on the window panes.
To eliminate said disadvantages, the use of polymeric substances having softening properties has been recommended.
DE 2 629 748 claims the use of copolymers of monoolefins having 10 to 30 carbon atoms and maleic anhydride to fill and fat liquor leathers and fur skins. Soft and full leathers are obtained even without using additional fat liquors and greases. However, large amounts of difficultly degradable organic solvents, such as paraffin oils or xylenes, are necessary in the production of the copolymers; a fact that is not desired any longer from today's ecological point of view.
DE 3 926 167 A1 proposes the use of copolymers of long-chain monoolefins with ethylenically unsaturated dicarboxylic acid anhydrides to make leather and fur skins hydrophobic. The difference to DE 2 629 748 lies in the fact that a solvolysis of the anhydride groups of the polymer is carried out after the polymerization by means of alcohols or amines, whereby a maximum of 50 mole-% of the present anhydride groups shall be esterified or amidated in this manner. According to this application, alcohols having 1 to 40, preferably 3 to 30 carbon atoms are suitable for this purpose. There is no indication with respect to the use of alcohols having an additional ether function. Solid contents of 10 to 60%-wt., preferably 20 to 55%-wt. are claimed for the polymers obtained by mass polymerization, however, in the examples a maximum solid content of only 30% is obtained.
For the same purpose, i.e., making leathers and furs hydrophobic, DE 39 31 039 A 1 proposes the use of copolymers comprising incorporated by polymerization a)i 50 to 90%-wt. C.sub.8 to C.sub.40 -alkyl(meth)acrylates or vinyl esters of C.sub.8 to C.sub.40 -carboxylic acids and b) 10 to 50%-wt. monoethylenically unsaturated C.sub.3 to C.sub.12 -carboxylic acids, monoethylenically unsaturated dicarboxylic acid anhydrides, semiesters or semiamides of monoethylenically unsaturated C.sub.4 to C.sub.12 -dicarboxylic acids, amides of C.sub.3 to C.sub.12 -monocarboxylic acids or mixtures thereof. If maleic anhydride is used as monomer of group b), this is at least partially neutralized or solvolised in the above meaning after termination of the polymerization.
The preparation of the polymers is effected ei

REFERENCES:
patent: 3721654 (1973-03-01), Schlumbom et al.
patent: 3721655 (1973-03-01), Schlumbom et al.
patent: 4931197 (1990-06-01), Beck et al.
patent: 5124181 (1992-06-01), Schaffer et al.
patent: 5279613 (1994-01-01), Schaffer et al.
patent: 5425784 (1995-06-01), Denzinger et al.
patent: 5433752 (1995-07-01), Birkhofer et al.

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