Rubber compositions with a high elastic modulus

US5196483A · kind A · utility

Assignee

• American Cyanamid Company · US

Inventors

• Daniel Zimmerman · Stratford, US
• John Milks · Stamford, US
• Sidney Binder · Stamford, US
• Roger J. Card · Paris, FR
• Winfried Wunderlich · Roßdorf, DE
• Werner Siol · Pfungstadt, DE

Key dates

• Filing date: Jul 6, 1990
• Grant date: Mar 23, 1993
• Expiry date: Jul 6, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F255/06
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Modified rubber compositions comprise by weight about 15-60% of a highly saturated aliphatic rubber such as ethylene-propylene-diene rubber, about 25-80% of acrylate monomer units; and less than about 5% multi-functional monomer units. The compositions exist as amorphous heterogeneously dispersed phases. The first phase comprises the copolymer rubber to which polymers of at least 10% of the other monomer units are grafted. The second phase comprises the other monomers polymerized as homo and copolymers, not grafted to the rubber. Optionally, up to 20% of the composition comprises high index monomer units. The high index monomer units may be copolymerized with the acrylate and grafted to the rubber. Greater than 10% of the monomer units other than rubber are grafted to the rubber. The number average molecular weight of the grafts is between 10,000 and 80,000 daltons. About 2-20% by weight of one or more polymers may be provided to adjust the refractive indices of the rubber or the polyacrylate phase in the final product such that when the composition is present at the 10% rubber level, the haze can be reduced to less than 20%.