Abstract:
A diene rubber composition comprising 25 to 90 parts by weight of at least one high molecular weight diene rubber (A) having an intrinsic viscosity [.eta.] of at least 2.0 and a glass transition point of not lower than -50.degree. C. and 75 to 10 parts by weight of at least one low molecular weight diene rubber (B) having an intrinsic viscosity [.eta.] of 0.01 to 2.0, said composition having an average intrinsic viscosity of at least 1.8.Since this composition has an excellent wet grip and rolling resistance property and moreover has excellent processability, it is employed as tire tread rubber.
Abstract:
A conjugated diene block polymer composed of blocks having a different microstructure from each other such that one block contains 20 to 60% by mole of 1,2- and/or 3,4-bonding, the other block contains 50 to 90% by mole of 1,2- and/or 3,4-bonding, the difference in the 1,2- and/or 3,4-bonding content between the both blocks is from 20 to 50% mole and the average content of 1,2- and/or 3,4-bonding in the polymer is from 50 to 85% by mole. The block polymer has a high wet skid resistance and a low dynamic heat generating property, and is very useful as a material for automobile tires.
Abstract:
A rubber composition containing an isoprene homopolymer or copolymer having a glass transition temperature of not less than -50.degree. C. and a Mooney viscosity of 20 to 120. The composition can provide a cured rubber having a high wet road gripping force and a small dynamic heat generating characteristic, and is very suitable for use in tires of automobiles.
Abstract:
Processes for preparing 1-benzyl-4-[(5,6-dimethoxy-lindanon)-2-yl]methylpiperidine (donepezil), which is useful as an intermediate for medicines, and for producing 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine hydrochloride (donepezil hydrochloride), which is useful as a medicine. The process for donepezil hydrochloride production comprises catalytically hydrogenating the compound represented by the structural formula (III) [1-benzyl-4-[(5,6-dimethoxy-lindanon)-2-ylidene]methylpiperidine] with a Raney nickel catalyst under mild conditions and subsequently treating it with hydrochloric acid. Thus, impurities are further diminished. The operations are simple and the process is suitable for industrial production.
Abstract:
An α-olefin polymerization catalyst comprising (A) a solid catalyst component containing a titanium compound obtained by treating a solid product having a titanium content of 1.5% by weight or less obtained by reducing Ti(OR1)aX4-a (R1 represents a hydrocarbon group having 1 to 20 carbon atoms, X represents a halogen atom and a represents a number satisfying 0
Abstract:
A catalyst for &agr;-olefin polymerization obtained by contacting (A) a solid catalyst component containing a titanium compound which is obtained by treating a solid product obtained by contacting an organosilicon compound having an Si—O bond, an ester compound and an organomagnesium compound, with an ether compound, titanium tetrachloride and an acyl halide, and successively treating said treated solid with an mixture of an ether compound and titanium tetrachloride, or a mixture of an ether compound, titanium tetrachloride and an ester compound, (B) an organoaluminum compound and (C) an electron-donative compound, and a process for producing an &agr;-olefin polymer with the catalyst.
Abstract:
Donepezil hydrochloride, 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine hydrochloride, is provided here in the form of four polymorphs which are stable against heat and humidity in the pharmaceutical use. They can be industrially produced. They are specified by peaks in X-ray powder diffraction pattern and absorption peaks in infrared absorption spectra in potassium bromide.
Abstract:
A transition metal complex represented by the formula [1] ##STR1## wherein M is a transition metal atom of the group 4 of the periodic table of elements; Cp is a group having a cyclopentadiene type anionic skeleton; A and G are each a divalent residue containing an atom of the group 15 or 16 of the periodic table of elements and may be the same with or different from each other; X.sup.1, X.sup.2, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each independently a hydrogen atom, halogen atom, alkyl group with the number of carbon atoms of 1-20 optionally substituted with at least one halogen atom, aralkyl group with the number of carbon atoms of 7-20 optionally substituted with at least one halogen atom, aryl group with the number of carbon atoms of 6-20 optionally substituted with at least one halogen atom, substituted silyl group with the number of carbon atoms of 1-20 optionally substituted with at least one halogen atom, alkoxy group with the number of carbon atoms of 1-20 optionally substituted with at least one halogen atom, aralkyloxy group with the number of carbon atoms of 7-20 optionally substituted with at least one halogen atom, aryloxy group with the number of carbon atoms of 6-20 optionally substituted with at least one halogen atom or a di-substituted amino group with the number of carbon atoms of 2-20, provided that R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may optionally combine with each other to form a ring; L is a Lewis base and w is an integer of 0-2, an olefin polymerization catalyst and a process for producing olefin polymers which uses the catalyst.
Abstract:
Donepezil hydrochloride, 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine hydrochloride, is provided here in the form of four polymorphs which are stable against heat and humidity in the pharmaceutical use. They can be industrially produced. They are specified by peaks in X-ray powder diffraction pattern and absorption peaks in infrared absorption spectra in potassium bromide.
Abstract:
An .alpha.-olefin polymerization catalyst system having so high a catalytic activity and stereoregularity that the catalyst residue and amorphous polymer need not be removed and a process for producing an.alpha.-olefin polymer using the catalyst system, said catalyst system consisting essentially of:(A) a trivalent titanium compound-containing solid catalyst component prepared by reducing a titanium compound, represented by the general formula Ti(OR.sup.1).sub.a X.sub.4-a in which R.sup.1 represents a hydrocarbon group having 1 to 20 carbon atoms; X represents a halogen atom; and a represents a numeral satisfying 0
Abstract translation:具有如此高的催化活性和立构规整性的催化剂残余物和无定形聚合物不需要除去的α-烯烃聚合催化剂体系和使用该催化剂体系生产α-烯烃聚合物的方法,所述催化剂体系基本上由以下组成:(A )通过还原由通式Ti(OR 1)a X 4-a表示的钛化合物制备的含三价钛化合物的固体催化剂组分,其中R 1表示具有1至20个碳原子的烃基; X表示卤原子; 和a表示满足0