| 摘要 |
Tackifying cements for ethylene/propylene copolymers and ethylene/propylene/diene terpolymers comprise by weight blends of solutions in aliphatic hydrocarbon or chlorine-substituted aliphatic hydrocarbon solvents of (1) 100 parts of an ethylene/propylene copolymer or ethylene/propylene/diene terpolymer having a reinforcing filler incorporated therein; (2) 5 to 25 parts of a raw polymer cohesive agent; and (3) a mixture of 10 to 40 parts of a tackifying resin and as softening agent 20 to 100 parts of a polymer of a C3- 6 a -olefin, e.g. low molecular weight polybutene-1 or amorphous polypropylene, the cement having a solids content of 5 to 20%. Specified solvents are hexane, naphtha, 1,1,2 - trichloroethane, trichloroethylene and carbon tetrachloride. The reinforcing filler may be carbon black or silica. The cohesive agent may be polychloroprene, butyl rubber, halogenated butyl rubbers, chlorosulphonated polyethylene, chlorinated polyethylene and polyisobutylene. The tackifying resin may be an alkylphenol/formaldehyde or alkylphenol/acetylene condensate. Improved tack retention may be obtained by incorporating a low molecular weight ethylene/propylene/diene terpolymer in (1), e.g. obtained by hydrogen modification or thermal depolymerization. Examples describe cements comprising (1) copolymers and terpolymers with and without low molecular weight terpolymer, reinforced with carbon black and containing conventional curatives; (2) butyl rubber; and (3) mixtures of p-t. butylphenol/ acetylene condensates and polybutene-1, the components being dissolved and the resulting solutions combined. |
