Abstract:
A process is provided for the preparation of an aminothiadiazolylacetyl halide derivative represented by the following formula (II): ##STR1## wherein R.sup.1 represents a lower alkyl, cycloalkyl or halogenated lower alkyl group; and R.sup.2 represents an amino-protecting group or a hydrogen atom, or a salt thereof, which process uses as the starting material a compound represented by the following formula (I): ##STR2## wherein R.sup.1 and R.sup.2 have the same meanings as defined above, or a salt thereof.
Abstract:
A modified polymer rubber is obtained by(1) graft-polymerizing at least one grafting monomer to a shreaded rubbery polymer (A) in an aqueous suspension at a temperature of 30.degree.-130.degree. C. to obtain a graft polymer, and(2) kneading the graft polymer with at least one polymerizable monomer in the presence of a free radical initiator at a temperature of 180.degree.-280.degree. C. This process does not cause gel formation and is advantageous in manufacturing cost.The modified polymer rubber thus obtained is excellent in processability and storage stability, and highly useful as a compatibilizer for various resins.
Abstract:
A process for preparing modified diene polymer rubbers having an increased impact resilience, a reduced hardness at low temperatures and an improved processability, and useful as rubber materials for automobile tires and other industries which comprises producing a conjugated diene polymer having alkali metal end or ends, and reacting the alkali metal-containing polymer with (a) a silicon or tin compound of the formula: R.sub.a MX.sub.b wherein R is an alkyl group, an alkenyl group, a cycloalkenyl group or an aromatic hydrocarbon group, M is silicon atom or tin atom, X is a halogen atom, a is 0, 1 or 2 and b is 2, 3 or 4, and (b) at least one member selected from the group consisting of a nitro compound; a phosphoryl chloride compound of the formula (1): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are an alkyl group; an aminosilane compound of the formula (2): ##STR2## wherein R.sup.5, R.sup.6 and R.sup.7 are an alkyl group or an alkoxyl group, R.sup.8 and R.sup.9 are an alkyl group, and n is an integer; an acrylamide compound of the formula (3): ##STR3## wherein R.sup.10 is hydrogen atom or methyl group, R.sup.11 and R.sup.12 are an alkyl group, and m is an integer; and an aminovinylsilane compound of the formula (4): ##STR4## wherein R.sup.13, R.sup.14, R.sup.15, R.sup.16 and R.sup.17 are an alkyl group.
Abstract:
A tire tread rubber composition which is improved in grip characteristic, steering stability characteristics and low-temperature characteristics, containing 15 to 50 parts by weight of a particular styrene-butadiene rubber obtained by solution polymerization containing polymer chains modified with trifunctional and/or tetrafunctional coupling agents, 50 to 85 parts by weight of at least one rubber selected from the group consisting of emulsion-polymerized styrene-butadiene rubber, natural rubber, synthetic polyisoprene rubber and butadiene rubber, at least one compound as plasticizer selected from the group consisting of a sebacic acid ester, an adipic acid ester and a fatty acid ester, and carbon black having an average particle size of not more than 30 m.mu..
Abstract:
In a process for producing a high impact polystyrene comprising the radical polymerization of styrene in the presence of a butadiene rubber, the improvement which comprises, the butadiene rubber being a highly branched polymer prepared by homopolymerizing 1,3-butadiene or copolymerizing 1,3-butadiene and styrene in the presence of an organolithium compound and a Lewis base compound, followed by further reacting the resulting polymer with a multifunctional halogen compound; in the butadiene rubber, the average content of 1,2-bonds being 18 to 32 mole % based on the total bonded butadiene, the content of bonded styrene being up to 10% by weight, and the content of branched polymer chains being at least 60% by weight; the butadiene rubber exhibiting a Mooney viscosity of 40 to 90 at 100.degree. C. and a solution viscosity in styrene of 60 to 90 cps at 25.degree. C. and at a concentration of 5% by weight; and the styrene polymerization being carried out so that the content of the butadiene rubber in the product polystyrene lies between 3 and 20% by weight.
Abstract:
A branched polymer which is a butadiene homopolymer or a copolymer of an aromatic vinyl compound and butadiene and has a glass transition temperature of not less than -50.degree. C. and of which at least 70% by weight of the polymer chains has a branched structure in which high molecules are coupled by a trifunctional or tetrafunctional coupling agent, has an excellent roll processability as required in mixing a rubber component with additives and provides a rubber component for tire tread showing a low rolling resistance and an excellent wet skid resistance characteristic.
Abstract:
An aromatic vinyl compound and a conjugated diene are block-copolymerized in a hydrocarbon solvent using an organolithium compound as an initiator to form a hydrocarbon solution of a block copolymer resin which is then steam-stripped off the solvent in the presence of a specified block polyether type dispersing agent to yield a granular polymer. The block copolymer thus obtained has favorable properties as granules and can be fabricated into articles being highly transparent and having excellent mechanical properties.
Abstract:
A driven-side rotator is rotatable synchronously with a camshaft and is supported between a gear member and a sprocket member of the driving-side rotator in an axial direction. A stopper portion of the driven-side rotator is adapted to contact the driving-side rotator in a rotational direction to limit a change in a relative phase between the crankshaft and the camshaft. The stopper portion radially outwardly projects from a small diameter portion provided at one end part of the driven-side rotator. A large diameter portion is provided at the other end part of the driven-side rotator and has a radial size that is measured from a rotational axis to a radially outer peripheral surface of the large diameter portion and is equal to or larger than that of the stopper portion.
Abstract:
A valve timing adjusting apparatus includes a driving-side rotor, a driven-side rotor, a sun gear, and a planet gear. The driving-side rotor is rotatable synchronously with the crankshaft. The driven-side rotor is received in the driving-side rotor and rotatable synchronously with a camshaft. The sun gear is rotatable integrally with the driving-side rotor. The planet gear moves epicyclically relative to the sun gear. The driving-side rotor includes a peripheral wall member and a bottom wall member. One of the sun gear and the bottom wall member is fitted with an inner peripheral side of one axial end portion of the peripheral wall member. The other one is fitted with an outer peripheral side of the other axial end portion of the peripheral wall member.