| 摘要 |
An adhesive, binder or coating composition comprises a polyvinyl acetal, a butadiene rubber, and a phenol-aldehyde resin in proportions of 95-70 per cent acetal and 5-30 per cent rubber, and from 3 to 200 per cent of the phenol-aldehyde resin, the percentages being based on the sum of acetal and rubber. The butadiene rubber is either polybutadiene or a copolymer thereof containing at least 25 per cent butadiene, e.g. a copolymer with acrylonitrile, methyl acrylate, an alkyl methacrylate, vinyl pyridine, vinylidene chloride or dialkyl fumarate. Specified acetals are the formal, acetal and butyral. The phenol-aldehyde resin may be liquid or solid or a mixture of both. Volatile organic solvents such as a blend of toluene, ethyl alcohol and 1,4-dioxane and also water may be present. |
