Abstract A cement and technique for bonding stocks made from EPDM made with ethylidene norbornene or isopropylidene norbornene as the third monomer to conventional general purpose butadiene polymer rubber stocks are disclosed. The cement is made by dissolving compounded polybutadiene having a cis content not over 30%, a trans content of from 35% to 75%, a vinyl content of from 15% to 40%, and a combined trans and vinyl content of at least 70%, and an intrinsic viscosity greater than 2 in a volatile organic solvent. The surfaces of the two stocks to be joined are coated with this cement. The solvent is then caused to evaporate, the two surfaces are pressed together and the plied assembly of the two stocks is then cured under heat and pressure.
A BONDING CEEEMENT CONSISTING ESSENTIALLY OF A SOLUTION OF COMPOUNDED POL CEYBUTADIENE IN A VOLATILE ORGANIC SOLVENT, SAID POLYBUTADDIENE HAVING A CIS CONTENT OF 10% TO 25%, A TRANS CONTENT OF FROM 40% TO 70%, A VINYL CONTENT OF FROM 17% TO 35%, AND A COMBINED TRANS AND VINYL CONTENT AT LEAST EQUAL TO 70%, SAID PERCENTAGES BEING BY WEIGHT, AND AN INTRINSIC VISCOSITY GREATER THAN 2, SAID CEMENT COMPRISING COMPOUNDING AND VULCANIZING INGREDIENTS CAPABLE OF EFFECTING VULCANIZATION OF SAID POLYBUTADIENE.
Claim 2
Dependent Claim
81 words
A BONDING CEEEMENT CONSISTING ESSENTIALLY OF A SOLUTION OF COMPOUNDED POL CEYBUTADIENE IN A VOLATILE ORGANIC SOLVENT, SAID POLYBUTADDIENE HAVING A CIS CONTENT OF 10% TO 25%, A TRANS CONTENT OF FROM 40% TO 70%, A VINYL CONTENT OF FROM 17% TO 35%, AND A COMBINED TRANS AND VINYL CONTENT AT LEAST EQUAL TO 70%, SAID PERCENTAGES BEING BY WEIGHT, AND AN INTRINSIC VISCOSITY GREATER THAN 2, SAID CEMENT COMPRISING COMPOUNDING AND VULCANIZING INGREDIENTS CAPABLE OF EFFECTING VULCANIZATION OF SAID POLYBUTADIENE.
Claim 3
Dependent Claim
28 words
A cement as set forth in claim 1 in which the total solids content ranges from 3 to 20 parts by weight per 100 parts of the cement.
Claim 4
Dependent Claim
44 words
A cement as set forth in claim 1 wherein said vulcanizing ingredients include vulcanization accelerator which is approximately equally effective for EPDM rubber in which the third monomer is 5-ethylidene-2-norbornene, EPDM rubber in which the third monomer is 5-isopropylidene-2-norbornene, and general purpose butadiene rubbers.
Claim 5
Dependent Claim
14 words
A cement as set forth in claim 3 wherein said accelerator is a sulfenamide.
Claim 6
Dependent Claim
14 words
A cement as set forth in claim 4 wherein said accelerator is N-cyclohexyl-2-benzothiazole sulfenamide.