| 摘要 |
1286553 Crosslinking polymers on leather or synthetic leather BADISCHE ANILIN- & SODA-FABRIK AG 22 Dec 1969 [21 Dec 1968] 62282/69 Heading B2E [Also in Division C3] A process for dressing leather or synthetic leather substitute comprises applying to the surface of the leather or leather substitute (1) a solution or dispersion (aqueous or non- aqueous) of a copolymer carrying acetoacetate groups and/or cyano-acetate groups, and (2) one or more aldehydes and/or compounds capable of dissociating to give an aldehyde, as cross-linking agent; the major part of the crosslinking of the copolymer by means of the cross-linking agent occurring only after application of components (1) and (2) to said surface. Component (1) is suitably derived from a monomer of the formula where X is C 2 -C 10 alkylene or oxa alkylene, R is H or methyl and Y is acetyl or cyano, or from acetoacetates and cyanoacetates vinyl thioalcohols, e.g. vinyl thioglycol acetoacetate; these monomers are copolymerised with, for example, acrylic or methacrylic acid and alkyl and hydroxyalkyl esters thereof, vinyl esters of carboxylic acids, (meth)acrylonitrile, N- hydroxymethyl amides of (meth)acrylic acid and their alkyl ethers, (methyl)allylalcohol, vinyl chloride, vinylidene chloride, butadiene or mixtures thereof. Specified as component (2) are formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, glyoxal, acrolein, methacrolein, dimethylolurea and hexamethylenetetramine. The solutions or dispersions may optionally contain additives such as plasticisers, pigments, flow improvers and additional binding agents, e.g. phenolic resins, amino resins, alkyd resins, epoxide resins, acrylate resins or cellulose derivatives. To avoid a major amount of premature cross-linking, components (1) and (2) should be stored separately until required for use, except possibly when component (2) is not in free aldehyde form. The components are suitably applied to the leather or substitute by means of a two-component spray gun or a twocomponent casting machine. |
