Abstract: It has been found that saturated, halogen-containing polymers can be cross-linked to yield stable vulcanizates using 2,5-dimercapto-1,3,4-thiadiazole in the presence of certain basic materials in normal vulcanization procedures.
Abstract: A process for the cross-linking of high density polyethylene in the solid state according to which the polyethylene is admixed with the agents normally used for the vulcanization of unsaturated rubber compounds, then processed into the desired article and thereafter cross-linked at a temperature lower than the melting point of the polyethylene, the process being carried out in polyethylene containing a certain number of unsaturated bonds along the polymer chain.
Abstract: The present invention provides a process for the manufacture of vinyl chloride polymers by polymerization of the monomer or monomer mixture in aqueous dispersion in the presence of radical-forming catalysts and optionally suspension stabilizers, emulsifiers and further polymerization auxiliaries, which comprises carrying out the polymerization in a reactor the inner walls of which and other parts where polymer deposits may form are coated partially or entirely with a coating containing determined compounds of the formula ##STR1## In accordance with this invention, a substantial suppression of polymer deposit formation is achieved especially in the case of vinyl chloride copolymers.
Type:
Grant
Filed:
December 20, 1978
Date of Patent:
March 17, 1981
Assignee:
Hoechst Aktiengesellschaft
Inventors:
Edgar Fischer, Johannes Brandrup, Jurgen Weinlich
Abstract: A sulfur-curable acrylic rubber composition is provided which comprises [I] 100 parts of an acrylic rubber resulting from the copolymerization in the presence of a radical initiator of (1) 30 to 89.5% by weight of at least one alkyl acrylate with the alkyl group containing 1 to 8 carbon atoms, (2) 0.5 to 10% by weight of at least one monomer of the general formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, and R.sub.2 and R.sub.3, independently from each other, represent an alkyl group containing 1 to 3 carbon atoms, (3) 10 to 60% by weight of at least one alkoxyalkyl acrylate with the alkoxy group containing 1 to 4 carbon atoms and the alkylene group containing 1 to 4 carbon atoms, and 0 to 30% by weight of at least one of monovinyl and monovinylidene unsaturated compounds other than the said compounds; and [II] 1 to 5 parts by weight of a metal compound, and [III] 0.2 to 5 parts by weight, as sulfur, of at least one of sulfur and sulfur-containing organic compounds.
Abstract: The present invention relates to a vulcanizable rubber composition improved in a sulfur blooming obtained by coagulatingly keeping a supersaturated sulfur within said rubber composition. For preventing said sulfur blooming, in the present invention, a surface active agent such as sodium or potassium ethylxanthate, sodium or potassium isopropylxanthate, dialkyldithiophosphoric acid, diphenylthiourea, mercaptobenzothiazole, diphenylthiocarbazone, sodium oleate, sodium stearate or octadecylamineacetate is added to a rubber composition obtained by compounding sulfur as a vulcanizing agent in the amount of 0.5 to 10 parts by weight in relation to 100 parts by weight of rubber which may be any of natural rubber, synthetic rubber and the mixtures thereof.
Abstract: A thermally stable, curable fluoroelastomer composition containing sulfonium curing agent is described. The composition is curable in reactive admixture with an inorganic acid acceptor and includes:(a) a fluoroelastomer comprising vinylidene fluoride;(b) at least one triorgano sulfonium compound; and(c) at least one aromatic polyhydroxy compound.
Type:
Grant
Filed:
February 26, 1979
Date of Patent:
November 11, 1980
Assignee:
Minnesota Mining and Manufacturing Company
Abstract: A process for producing a sulfur-curable acrylic rubber is provided which comprises radical-copolymerizing (1) an alkyl acrylate with (2) an alkenyl acrylate or methacrylate, or radical-copolymerizing (1) an alkyl acrylate, (2) an alkenyl acrylate or methacrylate, (3) an alkoxyalkyl acrylate and optionally (4) acrylonitrile. These acrylic rubbers can be cured at a rate as fast as those for curing diene-type rubbers, and the cured products exhibit superior properties without long heat-treatment after curing.
Abstract: A vulcanizable rubber composition having an excellent adhesive property when vulcanized in contact with metals is obtained by compounding(a) 100 parts by weight of a raw rubber(b) from 0.5 to 10 parts by weight of a vulcanizing agent, and(c) from 0.01 to 1 part by weight (as metal content) of at least one metal compound selected from the class consisting of organic acid salts of titanium and molybdenum and organic complex compounds of titanium, molybdenum and cobalt.The vulcanizable rubber composition thus obtained is not susceptible to the oxidative deterioration in unvulcanized state during the storage.
Abstract: A rubber composition and a process for the preparation of rubber compositions comprising, in the presence of a metal oxide, vulcanizing, or vulcanizing after blending with another unsaturated rubber, of the reaction product of (1) an unsaturated rubber, sulfur and a sulfur cleaving agent, (2) an unsaturated rubber and a mercaptan compound, (3) a halogenated unsaturated rubber and a metal salt of a sulfur cleaving agent, or (4) an unsaturated rubber, a sulfur cleaving agent and a compound having a functional group such as a nitrile oxide, a nitroso or a thionylamine.
Abstract: An elastomeric interpolymer, method of preparation and blends thereof, where said interpolymer is comprised of (A) a conjugated diene, (B) a comonomer of selected esters and amides and (C) optionally a termonomer selected from at least one of (1) particular conjugated vinylic monomers and (2) selected alkyl esters. The elastomeric interpolymer is particularly useful for the production of industrial goods, especially when blended with thermoplastic materials.
Abstract: This invention is directed to a method, a rubber skim stock and a product containing the skim stock having improved adhesion between a metal member and contiguous rubber skim stock. The invention lies in the discovery that improved rubber-to-metal adhesion can be obtained by adding to an otherwise conventional rubber skim stock composition appropriate amounts of a transition salt of p-aminobenzoic acid.The method of this invention comprises the steps of mixing the transition salt of p-aminobenzoic acid into a rubber composition, bringing this composition into contiguous relationship with a metal member in an unvulcanized product and vulcanizing the product to yield the end product.
Type:
Grant
Filed:
September 8, 1978
Date of Patent:
May 20, 1980
Assignee:
The Firestone Tire & Rubber Company
Inventors:
Adel F. Halasa, Frederick J. Ravagnani, Steven E. Schonfeld
Abstract: Disclosed is a sulfur-cured rubber article that has high resistance to reversion and low compression set which is post-modified to improve its fatigue life. The method involves introducing additional elemental sulfur in solution into the low sulfur-cured rubber article subsequent to curing.
Abstract: Compounds of the formula ##STR1## IN WHICH R.sub.1 and R.sub.2 independently are hydrogen, alkyl or aryl are described which compounds are potent inhibitors of premature vulcanization of rubber.