摘要:
Three-component accelerator system for the vulcanization of rubber, one accelerator being 2-(morpholinodithio)-benzothiazole, a second accelerator being a compound such as 2-(morpholinothio)benzothiazole, and a third accelerator being a thiuram such as tetramethylthiuram disulfide.
摘要:
Simple metal salts are found to be useful as primary accelerators for the sulfur vulcanization of nonpolar, unsaturated hydrocarbon rubbers. Useful metals include those of Group I-A, Group II-A, and transition metals of the periodic table including mixtures thereof. The metals are usually employed in the form of metallo-organic compounds. However, certain inorganic metal salts such as metal halides, carbonates and nitrates are also applicable.
摘要:
Rubber is cross-linked by heating with compounds of the formula (Acc-SSx)nR wherein Acc-S- is an accelerating moiety, R is an organic bridging group and n is two or more. If it is postulated that cross-link formation results from direct reaction of accelerator polysulfide intermediates via a concerted mechanism and that there is ultimately formed from reaction of accelerator and sulfur a polysulfide, Acc-SSx-S-Acc, the simplest cross-linking reaction involves formation of rubber intermediate combining the accelerator moiety followed by formation of sulfur cross-linked rubber and regeneration of the accelerator moiety. Consistent with these postulations, crosslinking of rubber is described with a compound containing two Acc-SSx- groups connected through the organic bridging group R which becomes part of the cross-link.
摘要:
A combination of a vulcanization accelerator and an inhibitor which allows longer and safer processing time for rubber, the inhibitor being characterized by the nucleus
摘要:
Sulfonamides such as N-methyl-N-(piperidinothio)-ptoluenesulfonamide are used to affect the vulcanization characteristics of sulfur vulcanizable polymers by increasing the state of vulcanization and/or improving scorch resistance and/or increasing the rate of vulcanization.
摘要:
A PROCESS FOR THE VULCANIZATION OF TERPOLYMERS OF ETHYLENE AND PROPYLENE, ALSO KNOWN AS EPDM RUBBERS, IS DESCRIBED. MORE PARTICULARLY VULCANIZATION ACCELERATORS FOR SUCH A PROCESS HAVING THE FORMULA
(R-O)2-P(=S)-S-CO-S-P(=S)(-O-R)2
IN WHICH THE RADICALS R REPRESENT THE SAME OR DIFFERENT STRAIGHT CHAINED OR BRANCHED LOWER ALKYL RADICALS, EACH OF WHICH MAY BE SUBSTITUTED BY A LOWER ALKOXY GROUP, ARE DESCRIBED.
摘要:
A SEALANT IS MADE BY COMPOUNDING A GELLED DRING OR SEMI-DRYING OIL WITH AN ELASTOMER AND VULCANIZING THE MIXTURE. THE GELLING OF THE OIL MAY BE ACCOMPLISHED DURING THE COMPOUNDING STEP BY SELECTING A GELLING AGENT EFFECTIVE AT THE COMPOUNDING TEMPERATURE.
摘要:
CURBING OF SILICA PIGMENT LOSSES AND THE PROMOTION OF UNIFORMITY OF PRODUCT IN THE PREPARATION OF AN ELASTOMERSILICA PIGMENT MASTERBATCH ARE EFFECTED (A)~ BY COMBINING (1) AN AQUEOUS SLURRY OF HYDRATED SILICA PIGMENT PRECIPITATE WHICH HAS A BOUND ALKALI CONTENT, WHICH HAS BEEN PREPARED BY PRECIPITATION FROM AN AQUEOUS ALKALI METAL SILICATE SOLUTION, AND WHICH HAS BEEN CONTINUOUSLY MAINTAINED IN AN AQUEOUS PHASE WITHOUT HAVING BEEN DRIED AFTER ITS PRECIPITATION, WITH (2) A QUANTITY OF OLEOPHILIC QUATERNARY AMMONIUM MATERIAL, (3) COMBINING THE RESULTING TREATED SILICA PIGMENT SLURRY WITH A SOLVENT DISPERSION OF THE ELASTOMER, WITH OR WITHOUT (4) CARBON BLACK AND/OR PROCESSING OIL AND (5) SELECTED REACTANT, AND (B) REMOVING THE SOLVENT AND AQUEOUS PHASE AND RECOVERING
THE RESULTING COMBINATION AS A MASTERBATCH ESSENTIALLY WITHOUT LOSS OF SILICA PIGMENT.
摘要:
CURBING OF SILICA PIGMENT LOSSES AND THE PROMOTION OF UNIFORMITY OF PRODUCT INTHE PREPARATION OF AN ELASTOMERSILICA PIGMENT MASTERBATCH ARE EFFECTED (A) BY COMBINING (1) AN AQUEOUSLY WET HYDRATED SILICA PIGMENT PRECIPITATE WHICH HAS A BOUND ALKALI CONTENT, WHICH HAS BEEN PREPARED BY PRECIPITATION FROM AN AQUEOUS ALKALI METAL SILICATE SOLUTION, AND WHICH HAS BEEN CONTINUOUSLY MAINTAINED IN AN AQUEOUSLY WET STATE WITHOUT HAVING BEEN DRIED AFTER ITS PRECIPITATION, WITH (2) A QUANTITY OF OLEOPHILIC AMINE CARBOXYLATE MATERIAL, (3) COMBINING THE RESULTING TREATED SILICA PIGMENT SLURRY WITH A SOLVENT DISPERSION OF THE ELASTOMER, WITH OR WITH OUT (4) CARBON BLACK AND/OR PROCESSING OIL AND (5) SELECTED REACTANT, AND (B) REMOVING THE SOLVENT AND AQUEOUS PHASE AND RECOVERING THE RESULTING COMBINATION AS A MASTERBATCH ESSENTIALLY WITHOUT LOSS OF SILICA PIGMENT. THE WET PIGMENT MAY BE TREATED WITH WATER SOLUBLE SALT OF ALUMINUM, OR ZINC, OR THE ALKALINE EARTH METALS AND/OR WITH WATER SOLUBLE ACID, AS WELL AS WITH THE SAID AMINE CARBOXYLATE, AND AFTER SUCH TREATMENT THE RESULTING PIGMENT COMPOSITION MAY BE COMBINED AS IN (3), (4) AND (5) ABOVE, AND BE RECOVERED AS IN (B) ABOVE IN THE FORM OF A MASTERBATCH.
摘要:
SHRINKAGE IS NORMALLY OBSERVED UPON CURING MOLDING COMPOSITIONS BASED UPON 1,2-BUTADIENE POLYMERS HAVING AT LEAST 80% OF THE BUTADIENE CONTACT COMBINED THEREIN IN THE 1,2 FORM. SUCH SHRINKAGE IN BOTH UNFILLED AND FILLED COMPOSITIONS CAN BE GREATLY REDUCED WITHOUT REDUCING THE CURE RATE BY INCLUDING IN THE COMPOSITION A NORMALLY SOLID THERMOPLASTIC ORGANIC RESIN AND A NORMALLY LIQUID VINYL MONOMER IN AMOUNTS OF ABOUT 20-100 PARTS EACH, PER 100 PARTS BY WEIGHT OF BUTADIENE POLYMER. THE THERMOPLASTIC RESIN MUST BE AT LEAST PARTIALLY INCOMPATIBLE WITH THE BUTADIENE POLYMER WHEN THE COMPOSITION CURED. EXAMPLES OF SUCH THERMOPLASTIC RESIN INCLUDE METHYL METHACRYLATE POLYMER AND STYRENE POLYMER AND EXAMPLES OF SUCH VINYL MONOMER INCLUDE STYRENE.