Abstract: Blends are disclosed of monoolefin rubber with high-diene hydrocarbon rubber in which the monoolefin rubber is in the form of discrete vulcanized particles dispersed in a matrix of unvulcanized high-diene hydrocarbon rubber. The blends can be easily processed, and in a subsequent step, the high-diene hydrocarbon portion cured to give rubber articles having the ozone resistance of the monoolefin rubber and the good physical properties of the high-diene hydrocarbon rubber.
Abstract: Alkylthioalkanoic acids, salts or esters having the formulaR.sup.1 S(CR.sup.3 R.sup.4).sub.x CO.sub.2 R.sup.2where R.sup.1 represents an alkyl or alkenyl group, or a hydroxy- or alkoxy-substituted alkyl or alkenyl group, said group containing (apart from the alkoxy carbon atoms in an alkoxy-substituted alkyl or alkenyl group) from 4 to 22 carbon atoms, R.sup.2 represents hydrogen, a metallic or other cationic group, or an esterifying group, each of R.sup.3 and R.sup.4 represents independently hydrogen or an alkyl group, and x has a value of from 1 to 10, act as viscosity-modifying agents in unvulcanized rubber compositions. Compared with conventional processing aids, they improve the processing characteristics of unvulcanized rubber compositions and can have beneficial effect on the physical properties of vulcanisates obtained by the vulcanization of such compositions.
Abstract: Crosslinking of rubber having a carboxylic functionality is accomplished by heating the rubber in the presence of an isocyanate functionalized compound and an accelerator which is a metal salt of an organic acid. The crosslinked polymers are useful in a variety of shaped articles, and can be in the form of dispersed particles, in a continuous plastic phase.
Abstract: Butadiene polymer rubber compositions containing a polymeric activator have particularly beneficial characteristics. The activator is an interpolymer of a vinylpyridine monomer and a diene hydrocarbon monomer which interpolymer contains from 20% to 65% by weight of vinylpyridiene units. Composite articles made from these rubber compositions together with contiguous portions of a dissimilar rubber compound show greater strength and adhesion as a result of the presence of a activator in the butadiene polymer rubber composition.
Abstract: Mixtures of N,N'-disubstituted paraphenylenediamines are produced in a process wherein a nitrogen-containing compound such as 4-nitrodiphenylamine is reductively alkylated with a plurality of ketones in sequence. Preferably, one ketone is reacted to completion with an excess of the nitrogen-containing compound, then an excess of a second ketone is added and the reaction is continued until the nitrogen-containing compound is consumed. The product is then separated from the volatiles and the unreacted portion of the second ketone is recovered.
Abstract: Butadiene polymer rubber compositions containing a polymeric activator have particularly beneficial characteristics. The activator is an interpolymer of a vinylpyridine monomer and a diene hydrocarbon monomer which interpolymer contains from 20% to 65% by weight of vinylpyridine units. Composite articles made from these rubber compositions together with contiguous portions of a dissimilar rubber compound show greater strength and adhesion as a result of the presence of the activator in the butadiene polymer rubber composition.
Abstract: Shaped articles are made from blends of rubber and plastic in which the rubber is in the form of discrete vulcanized particles dispersed in the plastic. After shaping the articles, they are exposed to free-radical crosslinking which converts the blends from thermoplastics to thermosets.
Type:
Grant
Filed:
October 13, 1987
Date of Patent:
February 28, 1989
Assignee:
Monsanto Company
Inventors:
Raman Patel, Yun L. Wang, Sabet Abdou-Sabet
Abstract: A method and apparatus for testing samples of viscoelastic materials are shown, in which the sample is subjected to a sinusoidal excitation and the response to the excitation is measured. By sampling the response at at least three data points equally spaced through a single cycle of excitation and making the proper calculations based on the data points, the storage modulus or the loss modulus of the materials, or both, can be obtained. The apparatus includes a rotary drive, eccentric, sample holder, a rotor or moving die, a torque transducer, excitation means, response measuring means, data handler and a sampler to obtain responses at predetermined intervals.
Abstract: Blends are disclosed of monoolefin rubber with high-diene hydrocarbon rubber in which the monoolefin rubber is in the form of discrete vulcanized particles dispersed in a matrix of unvulcanized high-diene hydrocarbon rubber. The blends can be easily processed, and in a subsequent step, the high-diene hydrocarbon portion cured to give rubber articles having the ozone resistance of the monoolefin rubber and the good physical properties of the high-diene hydrocarbon rubber.
Abstract: The bond strength between a sulphur-vulcanisable rubber and a metal, especially brass, is increased by using as bonding promoter an organic substance containing one or more groups of the formula --S--SO.sub.2 R where R represents (a) a radical --OM where M is a monovalent metal, the equivalent of a multivalent metal, a monovalent ion derived by the addition of a proton to a nitrogeneous base or the equivalent of a multivalent ion derived by the addition of two or more protons to a nitrogeneous base, or (b) an organic radical. Preferred promoters include sodium, zinc, nickel and cobalt organothiosulphates.
Type:
Grant
Filed:
April 12, 1985
Date of Patent:
November 3, 1987
Assignee:
Monsanto Europe, S.A.
Inventors:
Jean-Marc Delseth, Daniel E. Mauer, Philippe G. Moniotte
Abstract: A rubber blend is produced by masticating a mixture of monoolefin copolymer rubber and high-diene hydrocarbon rubber while dynamically vulcanizing the monoolefin copolymer rubber. The blend is then further treated to vulcanize the high-diene hydrocarbon rubber portion. The resulting vulcanized blend has improved properties.
Abstract: A tire chuck is disclosed which is designed with stepped ridges so as to accommodate a range of tire sizes, and is constructed of a material which is deformable and is relatively transparent to, and not degraded by x-rays.
Abstract: Additives for rubber compositions, giving vulcanisates having improved retention of optimum physical properties, are polymeric trithiocarbonates having a structure comprising repeating units of the formula ##STR1## where R is an organic bridging group, e.g. an alkylene group.
Type:
Grant
Filed:
September 9, 1985
Date of Patent:
May 12, 1987
Assignee:
Monsanto Europe S. A.
Inventors:
Albert F. L. G. Devaux, Philippe G. Moniotte
Abstract: A cutting device for rubber samples produces constant-volume samples of rubber. The samples are suitable for testing, such as curemeter or rheometer testing, and their constant volume eliminates erratic test results caused by samples which are too large or too small. The device features a sizing mechanism which works in conjunction with a cutter, so as to ensure constant volume samples.
Abstract: Polynetwork EPDM rubber is EPDM rubber containing both ionomeric and covalent cross-links, and can be formed by treating EPDM rubber with maleic acid or anhydride or fumaric acid to attach succinic groups to the rubber, forming an ionomer thereof with a polyvalent metal oxide, hydroxide or salt, and then covalently cross-linking the rubber, for example, by sulfur vulcanization. Compositions are shown containing the polynetwork rubber in combination with oil and black, optionally in blends with high-diene hydrocarbon rubber, such as natural rubber.
Abstract: Additives for rubber compositions, giving vulcanizates having improved retention of optimum physical properties, are compounds having the formula R--S--B--S--R where B is an organic bridging group and R is an electron-withdrawing group, for example CN, CCl.sub.3, a radical containing an activated methylene group linked to the sulphur atom or the enolic tautomer of a keto-activated methylene group. Also useful as stabilizing agents are oligomeric analogues of such compounds.
Type:
Grant
Filed:
September 13, 1985
Date of Patent:
April 14, 1987
Assignee:
Monsanto Europe, S. A.
Inventors:
Albert F. L. G. Devaux, Philippe G. Moniotte
Abstract: Compounds containing an organic thiosulphate anion and cationic nickel or cobalt in association with an amine, are useful in increasing the bond strength between metal, especially brass, and vulcanized rubber. Typical complexes are those where the anion is dodecylthiosulphate or hexamethylenebis(thiosulphate), and the amine is ethylenediamine or N-benzyl-N-t-octylamine.
Abstract: Compatibilized polymer blends are described comprising a blend of olefin polymer, cross-linkable acrylic ester copolymer rubber, and a compatibilizing amount of a graft copolymer comprising acrylic ester copolymer compatibilizing segments and olefin polymer compatibilizing segments.