| 摘要 |
A hot melt adhesive composition comprises a copolymer of vinyl acetate and crotonic acid dispersible in dilute aqueous alkali and as plasticizer, a methylated diaryl sulphone with at least one methyl substituent in each aryl group, e.g. dixylyl, ditolyl or tolyl xylyl sulphone, a mixture of isomeric methylated diaryl sulphones, or a chlorinated diphenyl. Fillers, e.g. asbestine, cotton flock, regenerated cellulose flakes, glass fibres; additional plasticizers, e.g. di-(ethylene glycol monoethyl ether) phthalate, triethyl citrate, tricresyl phosphate and citrate, dicresyl carbitol, butyl phthalyl butyl glycollate, o-cresyl p-toluene sulphonate and polyethylene glycol di-2-ethyl hexoate, or a modified rosin may be included. The copolymers may be prepared with the aid of catalysts, e.g. lauryl and benzoyl peroxides, a ,a 1-azo-bis-(isobutyronitrile), and a ,a 1-azo-bis-(a -g -dimethyl valeronitrile), solvents, e.g. toluene, benzene, ethyl alcohol and t.-butyl alcohol and inhibitors, e.g. a trisubstituted phenol "Ionol" (Registered Trade Mark). The product may be purified by dissolving in ammonium hydroxide and precipitating with hydrochloric acid. The plasticizer may be added to the monomeric mixture and the catalyst added in two portions. Copolymers containing up to 10 per cent crotonic acid may be used as book-binding adhesives. Other copolymers may be used as label adhesives for glass or metal containers. Adhesive contaminated waste paper may be repulped at about 5 per cent consistency in water and deinked at between 110 DEG and 180 DEG F., using, for example, sodium silicate and sodium peroxide, or caustic soda alone or mixed with soda ash. U.S.A. Specifications 1,073,324 and 2,471,959 are referred to. |
