Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
1999-06-10
2001-06-26
Hoke, Veronica P. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S496000, C525S074000
Reexamination Certificate
active
06251977
ABSTRACT:
The invention relates to an elastomer composition based on EPDM, and to a power transmission belt made of elastomer having said composition.
BACKGROUND OF THE INVENTION
Proposals have already been made on numerous occasions to use EPDM-based elastomers cured by organic peroxides in the manufacture of power transmission belts, because of the qualities and advantages of such elastomers such as cost, operating temperature range, and ability to withstand oxygen and ozone, such EPDM-based elastomers having additives which improve their dynamic properties such as resistance to fatigue and to wear, their breaking strength, and their modulus of elasticity, and also their adhesion to traction cords, which additives are generally constituted by metallic salts of &agr;,&bgr;-unsaturated organic acids (in particular zinc methacrylate) plus reinforcing fillers such as carbon black and possibly fibers, e.g. aramid fibers.
OBJECTS AND SUMMARY OF THE INVENTION
A particular object of the invention is to further improve the dynamic properties of EPDM-based elastomers, in particular for use in manufacturing power transmission belts.
To this end, the invention provides an elastomer composition for curing by organic peroxides, the composition essentially comprising, prior to curing, EPDM, at least one filler such as carbon black, for example, and a metallic salt of an &agr;,&bgr;-unsaturated organic acid, the composition comprising another additive which reacts with the above-specified metallic salt to enhance the curing of the elastomer, said other additive being essentially formed by an elastomer grafted with maleic anhydride.
Unexpectedly, the elastomer grafted with maleic anhydride reacts with the &agr;,&bgr;-unsaturated organic acid metallic salt to reinforce the curing of the EPDM-based elastomer and to improve its dynamic characteristics, such as in particular its modulus of elasticity, its breaking strength, and its hardness.
In general, the composition of the invention may comprise 2 to 30 parts by weight approximately of said other additive and 2 to 50 parts by weight approximately of the above-mentioned metallic salt per 100 parts by weight of EPDM.
In a preferred embodiment of the invention, said composition comprises about 3 to 5 parts by weight of said other additive and 15 to 25 parts by weight approximately of the above-mentioned metallic salt per 100 parts by weight of EPDM, the metallic salt is zinc methacrylate, in particular zinc mono-methacrylate, and the elastomer grafted with maleic anhydride is selected from polybutadiene, polyisoprene, polypropylene, and an ethyl vinyl acetate (EVA) copolymer.
It is also possible in a composition of the invention to use an elastomer comprising EPDM only or an elastomer which is a mixture of EPDM and some other elastomer such as hydrogenated nitrile rubber to improve resistance to oils and solvents (or possibly a nitrile rubber which is less expensive than hydrogenated nitrile rubber), and/or a polybutadiene to improve the dynamic properties and resistance to wear, or indeed a natural rubber to improve the raw adhesion, or a chlorosulfonated polyethylene with alkyl groups.
The invention also provides a power transmission belt, made essentially out of an elastomer having the above-defined composition.
REFERENCES:
patent: 3519609 (1970-07-01), McConnell et al.
patent: 3527736 (1970-09-01), Ayets Averink et al.
patent: 3644248 (1972-02-01), Luijk et al.
patent: 3884882 (1975-05-01), Caywood
patent: 4192790 (1980-03-01), McKinstry et al.
patent: 5098105 (1992-03-01), Sullivan
patent: 5300569 (1994-04-01), Drake et al.
patent: 5352739 (1994-10-01), Arjunan
patent: 5610217 (1997-03-01), Yarnell et al.
patent: 5962593 (1999-10-01), Hergenrother et al.
Georget Pierre
Morcel Julie
Hoke Veronica P.
Hutchinson
Morgan & Lewis & Bockius, LLP
LandOfFree
Elastomer composition based on EPDM, and a powder... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Elastomer composition based on EPDM, and a powder..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Elastomer composition based on EPDM, and a powder... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2455853