Patent GB-880980-A (GB)
Title: Improvements in or relating to the sizing of textile yarns and compositions therefor
Inventor: RIPLEY-DUGGAN BASIL ALEXANDER
IPC: D06M15/263
Filed: 1959-02-26
Abstract: A sizing composition for textile yarns comprises an aqueous solution of a mixture of polymeric materials which are capable of being dried and heated on the yarns to form a size which can be readily removed by aqueous media, the mixture of polymeric materials consisting of, in every 100 parts, between 15 and 50 parts of a hydroxylated polyvinyl compound containing between 35 and 50 hydroxyl groups for every 100 carbon atoms in the polyvinyl chain, and between 50 and 85 parts of a polymeric substance containing between 4 and 25 carboxyl group; for every 100 carbon atoms in the largest chain, such carboxyl containing polymeric substance being obtained by copolymerizing at least one ethylenically unsaturated carboxylic acid with vinyl acetate or with a mixture of ethylenically unsaturated compounds containing a major proportion of vinyl acetate.  The hydroxylated polyvinyl compound may be polyvinyl alcohol or a partially hydrolyzed or alcoholyzed vinyl ester polymer or copolymer.  The carboxyl-containing polymer may be derived from crotonic, acrylic, itaconic, fumaric or maleic acids or the lower alkyl half esters of the dibasic acids and carboxyl-free components such as ethylene, vinyl chloride, vinyl propionate or butyrate, acrylate or crotonate esters or dialkyl esters of itaconic, maleic or fumaric acid.  The solution may also comprise basic compounds, to effect solution of the copolymer, such as sodium or potassium hydroxides, carbonates or basic salts, ammonia, organic amines such as mono-, di- or tri-ethanolamine or quaternary ammonium hydroxides, and the solution may contain further known additives. An examples is given of the preparation of a copolymer from vinyl acetate and crotonic acid in aqueous dispersion in the presence of partially alcoholyzed polyvinyl acetate, using benzoyl peroxide as catalyst.  All the alcoholyzed polyvinyl acetate required in the final composition is present at the start of the polymerization and a graft copolymer is stated to be formed.ALSO:Textile yarns, e.g. polyester fibres, are sized using a composition comprising an aqueous solution of a mixture of polymeric materials which are capable of being dried and heated on the yarns to form a size which can be readily removed by aqueous media, the mixture of polymeric materials consisting of (in every 100 parts) between 15 and 50 parts of a hydroxylated polyvinyl compound containing between 35 and 50 hydroxyl groups for every 100 carbon atoms in the polyvinyl chain, and between 50 and 85 parts of a polymeric substance containing between 4 and 25 carboxyl groups for every 100 carbon atoms in the longest chain, such carboxyl containing polymeric substances being obtained by copolymerizing at least one ethylenically unsaturated carboxylic acid with vinyl acetate or with a mixture of ethylenically unsaturated compounds containing a major proportion of vinyl acetate.  The hydroxylated polyvinyl compound may be polyvinyl alcohol or a partially alcoholysed or hydrolysed vinyl ester polymer or copolymer.  The carboxyl containing polymer may be derived from crotonic, acrylic, itaconic, maleic or fumaric acid or the lower alkyl half esters of the dibasic acids and carboxyl-free components such as ethylene, vinyl chloride, propionate or butyrate, acrylate or crotonate esters of dialkyl esters of itaconic, maleic or fumaric acid.  The solution may also comprise basic compounds such as sodium or potassium hydroxides, carbonates or basic salts, ammonia or organic bases to effect solution of the copolymer, and the solution may also contain further known additives.  If volatile bases are present in the composition then the size may be insolubilised by heating to volatilise the base and an alkaline medium is necessary to remove the size.  The preferred concentration of polymers in the solution is between 5% and 25% and the preferred temperature is 40 DEG C. to 50 DEG C. to deposit at least 3% on the fibre.  After coating with the size the yarn may be passed over heated rollers or through drying chambers.