Colour indication in polyester resin curing

摘要

A room temperature curable polyester resin composition comprises an unsaturated polyester, a copolymerizable monomer, a colour indicator capable of imparting a transient colour to the polyester resin during curing with a peroxide catalyst and having the formula where Z is -S-, -NR1R2 or , wherein R, R1 and R2 are selected from hydrogen, alkyl, alkoxyalkylene, aryloxyalkylene, cycloalkyl, aryl and cycloalkoxyalkylene having 1 to 20 carbon atoms, Z being attached in an ortho or para position relative to the group, Y is selected from alkyl, aryl, alkoxy, and aryloxy having 1 to 20 carbon atoms and halogen and wherein n1 is 0 to 4 and n2 is 0 to 5, and a room temperature polyester resin curing promoter in an amount sufficient to compensate for any retarding effect of the colour indicator upon the curing of the resin. Conventional unsaturated polyesters, monomers, peroxide catalysts and promoters are used. Colour indicators employed in the examples are N,N1-di-b -naphthylphenylenediamine; diphenyl-p-phenylenediamine; 1,2 - benzophenothiazine; 2 - isopropoxy phenothiazine; N-ethoxymethyl-1,2-benzophenothiazine; N,N1-bis(ethoxymethyl)-N,N1-dinaphthylphenylenediamine N,N1 - di - iso -octyl dinaphthylphenylenediamine and phenothiazine.ALSO:A colour indicator composition capable of imparting a transient colour to a polyester resin during curing with a peroxide curing catalyst comprises a colour-indicator compound having the structural formula:- wherein Z is -S-; -NR1R2 or where R1 and R2 are selected from hydrogen, alkyl, alkoxyalkylene, aryloxyalkylene, cycloalkyl, aryl and cycloalkoxyalkylene having 1 to 20 carbon atoms and Z being attached in an ortho or para position relative to the group; Y is selected from alkyl, aryl, alkoxy and aryloxy having 1 to 20 carbon atoms and n1 is 0 to 4 and n2 is 0 to 5, and a room temperature polyester resin curing promoter in an amount sufficient to compensate for any retarting effect of the colour indicator upon the curing of the resin. Colour indicator comppounds employed in the examples are phenothiazine and substituted phenothiazines and substituted phenylenediamines. The promoters include cobalt salts of monocarboxylic acids and N,N-disubstituted anilines. Additional promoters such as zirconyl 2-ethyl -hexoate, hydrochloric acid, zinc chloride, ammonium chloride, organic phosphinic acid derivatives and n-butyl sulphite. The colour indicator compound is used in the resin mixture in an amount of 0.01 to 0.5% based on the weight of the resin. with a second roller which supplies paint from the reservoir 82 to the roller 92 or a brush (Fig. 7) which incorporates a flexible reservoir envelope 136 with an opening 144.