BINDEMITTEL FUER TEXTILE FASERGEBILDE.

摘要

Self crosslinking vinyl ester dispersions (i) with reduced or nil formaldehyde content are new. Dispersions are copolymers of: (a) 40-99 wt.% vinyl esters or branched or unbranched 1-12C carboxylic acids, (b) 1-60 wt.% vinyltrialkox and/or alkylvinyldialkoxysilanes with branched or unbranched 1-4C alkyl or alkoxy gps., (c) 0-40 wt.% ethylene, (d) 0-10 wt.% ethylenic unsatd. hydroxyalkyl cpds., (e) 0-10 wt.% ethylenic unsatd. carboxylic acid; (f) 0-5 wt.% ethylenic unsatd. carboxylic acid amides, N-alkyl amides, and/or N-alkoxyalkylamides; and (g) 0-1 wt.% multiple ethylenically unsatd. cpds. Pref. formaldehyde free dispersions contain no (f). Pref. (a) is e.g. vinyl acetate, vinyl propionate, pref. 70-98 wt.% for hard systems and 40-80 wt.% for soft. (b) 1-6 wt.% alkyl is CH3 and alkoxy is CH3O, C2H5O, pref. 1-4 wt.% vinyl trimethoxy, vinyltriethoxy silanes, (c) is pref. in soft systems 5-35 wt.%, (d) is 0-7.5 wt.% e.g. hydroxyethyl acrylate, or hydroxyproplyacrylate. (e) 0-5 wt.% monocarboxylic acid e.g. acrylic and ethylenically unsatd. dicarboxylics and their half esters e.g. maleic. (f) is e.g. acrylamide, N-methylol acrylamide at 0.5-2.5 wt.%. (g) 0-0.75 wt.% e.g. allylmethacrylate, or divinyladipate. (i) are prepd. by conventional emulsion polymerisation using free radical catalysis at 0-100 deg.C. Solids content is 45-60 wt.%. Crosslinking occurs at approx. 50 deg.C and content of binder on fibre is 20-40 wt.% of the dried material.