| 摘要 |
<p>A sizing composition comprises either: (i) the product obtained by polymerizing a C2-C4 alkyl acrylate with a gelatinized starch in the presence of a free-radical catalyst; or (ii) a blend of an aqueous starch paste and an aqueous emulsion of a polymerized C2-C4 alkyl acrylate, the compositions in both cases containing a nonionic surface active agent in an amount up to 30% of the combined weight of starch and acrylic ester, the water-soluble portion of the agent being a polyoxyethylene of from 2 to 120 units, and the ratio of starch to acrylic ester lying in the range of 7:3 to 1:19. The polymerized acrylic ester may contain a comonomer such as acrylic, methacrylic or itaconic acid, maleic anhydride or acrylamide. The starch used may be a native starch or a modified starch, e.g. oxidized, acid-modified or etherified, or a dextrin. The free-radical catalyst may be hydrogen peroxide, benzoyl peroxide, t-butyl hydroperoxide, sodium hypochlorite, persulphates and redox systems. Preferred surface active agents are octylphenoxy, nonylphenoxy, dioctylphenoxy, tridecylphenoxy and lauryl ethers of polyoxyethylenes.ALSO:Hydrophobic fibres, e.g. polyester fibres, are sized by applying thereto a composition comprising either: (i) the product obtained by polymerizing a C2-C4 alkyl acrylate with a gelatinized starch in the presence of a freeradical catalyst; or (ii) a blend of an aqueous starch paste and an aqueous emulsion of a polymerized C2-C4 alkyl acrylate, the compositions in both cases containing a non-ionic surface active agent in an amount up to 30% of the combined weight of acrylic ester and starch, the water-soluble portion of the agent being a polyoxyethylene of from 2 to 120 units, and the ratio of starch to acrylic ester lying within the range of 7:3 to 1:19. The polymerized acrylic ester may contain a comonomer, e.g. acrylic, methacrylic or itaconic acid, maleic acrylic, aretharacrific or itaconic acid, maleic anhydride or acrylamide. The starch may be a native starch or a modified starch, e.g. oxidized, acid-modified or etherified, or a dextrin. Preferred surface active agents are octylphenoxy, dioctylphenoxy, nonylphenoxy, tridecylphenoxy and lauryl ethers of polyoxyethylenes.</p> |
