| 摘要 |
Optically brightened shaped structures of linear polyamides are made by adding to the polyamide prior to its shaping, or to the starting materials from which the polyamide is manufactured, a substantially colourless sparingly water-soluble metal salt of an optical brightener of the formula:- <FORM:0878669/IV (a)/1> in which A1, A2, A3 and A4 are residues formed from a primary or secondary amine by removal of a hydrogen atom attached directly to the amino nitrogen atom and m and n are each 1 or 2. Specified polyamides are those derived from w-aminoundecanoic acid, e -aminocaproic acid, e -caprolactam and adipic acid and hexamethylene diamine. Specified metal salts are those of manganese, titanium, zinc, zirconium, aluminium, magnesium, strontium, barium and calcium. In the example 10,000 parts of polyhexamethylene adipamide having a molecular weight of about 13,000 is tumbled in the form of chips with 30 parts of titanium dioxide and 5 parts of the neutral calcium, barium, zirconium or magnesium salts of:- <FORM:0878669/IV (a)/2> the neutral barium salt of:- <FORM:0878669/IV (a)/3> the neutral barium salt of:- <FORM:0878669/IV (a)/4> and the aluminium salt of:- <FORM:0878669/IV (a)/5> the mixtures being melted and spun into filaments which are stretched.ALSO:The Specification discloses the preparation of sparingly water-soluble neutral calcium and barium salts of <FORM:0878669/IV (b)/1> by reacting the free disulphonic acid with calcium or barium hydroxide, the salts formed being optical brightening agents. Other optical brightening agents specified which it is stated are prepared by analogous methods are the neutral zirconium and magnesium salts of the above specified disulphonic acid, the neutral barium salts of <FORM:0878669/IV (b)/2> and <FORM:0878669/IV (b)/3> and the aluminium salt of <FORM:0878669/IV (b)/4> |
