| 摘要 |
554,268. Size. DU PONT DE NEMOURS & CO., E. I. Sept. 12, 1941, No. 11689. Convention date, Sept. 21, 1940. [Class 2 (iii)] A size for synthetic linear polyamide yarn comprises an aqueous solution containing 3 to 12 per cent. of a hydroxylated polyvinyl compound and 5 to 25 per cent. of boric acid based on the polyvinyl compound. The hydroxylated polyvinyl compound may be partially hydrolysed polyvinyl acetate, propionate, glycollate, formate or lactate, a partial ether of polyvinyl alcohol with glycol, glycollic acid, methyl or ethyl alcohol, partial polyvinyl formals acetals, propionals, butyrals, glyoxals, or partial polyvinyl ethyl methyl ketal. Examples include the preparation of (1) a partial polyvinyl formal by heating an aqueous solution of a low viscosity polyvinyl alcohol with formaldehyde and hydrochloric acid and neutralizing with ammonia and (2) a partial polyvinyl isobutyral by heating an aqueous solution of partially hydrolysed polyvinyl acetate with isobutyraldehyde and hydrochloric acid and neutralizing with caustic potash. Specifications 382,785, 413,624, 461,236, 461,237, 524,953 and U.S.A. Specification 2,157,116 are referred to. |
