Patent GB-431195-A (GB)
Title: Manufacture of coloured rubber products
IPC: C08K5/23
Filed: 1933-12-27
Abstract: Disazo dyes are obtained by tetrazotising benzidine or derivatives thereof containing halogen, alkyl or alkoxy groups and coupling with a 1 - phenyl - 5 - pyrazolone - 3 - carboxylic acid methyl or ethyl ester, the phenyl radical of which may contain halogen, alkyl or alkoxy groups.  They are used for colouring rubber.  The dyestuff 3 : 3<1> - dichloro - 4 : 4<1> - diaminodiphenyl \sQ 1 - phenyl - 5 - pyrazolone - 3 - carboxylic acid ethyl ester is referred to in an example.  Other components specified are tolidine, dianisidine, 2 : 2<1> - dichloro - 3 : 3<1>-dimethyl - 4 : 4<1> - diaminodiphenyl and 2 : 2<1>-dichloro - 5 : 5<1> - dimethoxy - 4 : 4<1> - diaminodiphenyl; 1 - (2<1> - chlorophenyl) -, 1-(2<1> : 5<1>-dichlorophenyl)-, 1-(4<1>-methylphenyl)-, and 1-(2<1>-chloro - 6<1> - methylphenyl) - 5 - pyrazole 3 - carboxylic acid methyl or ethyl ester.  The Specification as open to inspection under Sect. 91 refers also to the use of 1-phenyl-5-pyrazolone - 3 - carboxylic acid alkyl esters as coupling components and states that the dyes may be used in the manufacture of lakes.  The dyestuffs benzidine or dianisidine \sQ 1-phenyl - 5 - pyrazolone - 3 - carboxylic acid ethyl ester are described in examples.  Other components specified are 3 : 3<1> - dibromo -, 3 : 3<1> - dichloro - 2 : 2<1> - dimethoxy- and 6 : 6<1> - dichloro - 3 : 3<1>-diethoxy - 4 : 4<1>-diaminodiphenyl; 1 - (4<1> - bromophenyl) - 5-pyrazolone - 3 - carboxylic acid ethyl ester. This subject-matter does not appear in the Specification as accepted.ALSO:Rubber products (natural or synthetic) are coloured in clear yellow to red to violet shades by incorporating with the rubber products or mixtures containing them, prior to vulcanization, water-insoluble disazo dyes obtainable by tetrazotizing benzidine or derivatives thereof containing halogen, alkyl or alkoxy groups and coupling with a 1-phenyl-5-pyrazolone-3-car-boxylic acid methyl- or ethyl-ester, the phenyl radical of which may contain halogen, alkyl or alkoxy groups, and then vulcanizing the mixture. In examples, a mixture of cr<\>zepe rubber, stearic acid, sulphur, zinc white, mercaptobenzothiazole, hexamethylenetetramine, calcium carbonate, ozokerite, lithopone, titanium dioxide and the dyestuff 3 : 31-dichloro-4 : 41-diaminodiphenyl \sQ 1-phenyl-5-pyrazolone-3-carboxylic acid ethyl ester is vulcanized at steam pressure or by immersing in a solution of sulphur chloride in benzine.  The following dyestuff components are also specified: tolidine, dianisidine, 2 : 21-dichloro-3 : 31-dimethyl-4 : 41-diaminodiphenyl and 2 : 21 - dichloro - 5 : 51-dimethoxy - 4 : 41 - diaminodiphenyl ; 1 - (21-chlorophenyl)-, 1 - (21 : 51- dichlorophenyl)-, 1 - (41 - methylphenyl)-, and 1 - (21 - chloro - 61-methylphenyl) - 5 - pyrazolone - 3 - carboxylic acid methyl or ethyl ester.  The Specification as open to inspection under Sect. 91 refers also to the use of 1-phenyl-5-pyrazolone-3-carboxylic acid alkyl esters as coupling components and states that the dyes may be used for the manufacture of lakes.  The dyestuffs benzidine or dianisidine \sQ 1-phenyl-5-pyrazolone-3-carboxylic acid ethyl ester are described in examples and mixtures thereof respectively with cr<\>zepe rubber and (a) sulphur, thiuram, zinc white, ozokerite and stearic acid; (b) sulphur, paraffin oil, stearic acid, brown coal tar oil, colophony, calcium carbonate, zinc white, magnesium oxide, kaolin and thiuram.  Other dyestuff components specified are 3 : 31-dibromo-4 : 41-diaminodiphenyl, 3 : 31-dichloro-2 : 21-dimethoxy- and 6 : 61-dichloro-3 : 31-diethoxy-4 : 41-diaminodiphenyl ; 1 - (41 - bromophenyl) - 5 - pyrazolone-3-carboxylic acid ethyl ester.  This subject-matter does not appear in the Specification as accepted.