Patent GB-1047467-A (GB)
Title: Improvements in the treatment of leather
IPC: C14C7/00
Filed: 1963-09-11
Abstract: In stretching and finishing a sheet of leather, a thin layer of an aqueous adhesive composition, comprising a water-soluble cellulose derivative and a water-soluble polyhydric alcohol, having 2 to 6 hydroxyl groups per molecule and a viscosity not exceeding 100 centistokes at 99 DEG C., or an ether, preferably, a monoether thereof, and, if desired, a water-miscible organic solvent, such as a monohydric alcohol, is applied, as by brushes or rollers, to the sheet of leather, which is adhered, by means of said thin layer, to a plate, e.g. of glass and then dried together with the adhesive composition, e.g. at 30 DEG  to 50 DEG C.  The dried sheet of leather is removed from the plate and the dried adhesive composition is removed from the leather, as by applying water. The weight ratio of the cellulose derivative to the polyhydric alcohol or ether thereof may range from 1:10 to 3:1.  The adhesive composition may contain between 2 and 5 per cent, by weight, of the cellulose derivative and between 2 and 20 per cent of the polyhydric alcohol or ether thereof. Specified cellulose derivatives are: ethyl-hydroxyethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl-hydroxypropyl cellulose, ethyl cellulose, methyl cellulose, methyl ethyl cellulose, ethyl hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl carboxymethyl cellulose, sulphomethyl cellulose, sulphoethyl cellulose and cellulose sulphate. Specified polyhydric alcohols and ethers thereof are: glycerol, sorbitol, mannitol polyethylene glycol with a molecular weight between 200 and 5000, polypropylene glycol, polyethylene-propylene glycol, neopentyl glycol, triethylene glycol monomethyl ether, trimethylol propane and p-nonylphenol polyglycol ether, which is an adduct of p-nonyl phenol and ethylene oxide.ALSO:An aqueous adhesive composition, comprising a water-soluble cellulose derivative and a water-soluble polyhydric alcohol, having 2 to 6 hydroxyl groups per molecule and a viscosity not exceeding 100 centistokes at 99 DEG  C., or an ether, preferably, a monoether thereof, and, if desired, a water-miscible organic solvent, such as a monohydric alcohol, is used for stretching and finishing leather.  The weight ratio of the cellulose derivative to the polyhydric alcohol or ether thereof may range from 1 : 10 to 3 : 1. The adhesive composition may contain between 2 and 5% by weight of the cellulose derivative and between 2 and 20% of the polyhydric alcohol or ether thereof.  Specified cellulose derivatives are:  ethylhydroxyethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl - hydroxypropyl cellulose, ethyl cellulose, methyl cellulose, methyl ethyl cellulose, ethyl hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl carboxymethyl cellulose, sulphomethyl cellulose, sulphoethyl cellulose and cellulose sulphate. Specified polyhydric alcohols and ethers thereof are: glycerol, sorbitol, mannitol, polyethylene glycol with a molecular weight between 200 and 5000, polypropylene glycol, polyethylene-propylene glycol, neopentyl glycol, triethylene glycol monomethyl ether, trimethylol propane and p-nonylphenol polyglycol ether, which is an adduct of p-nonyl phenol and ethylene oxide.