Abstract: A polyethylene terephthalate resin composition comprising a polyethylene terephthalate resin and from 0.

Abstract: Disclosed herein is a transparent copolyamide which comprises constitutional units derived from a diamine component comprising (a) bis(3-methyl-4-aminocyclohexyl)methane and (b) hexamethylenediamine and a dicarboxylic acid component comprising (c) isophthalic acid and (d) terephthalic acid, the molar ratio of said components simultaneously satisfying the following two formulas:(a):(b)=3:97 to 18:82(c):(d)=60:40 to 90:10and relative viscosity of said copolyamide being 1.9 to 2.5 as measured at 25.degree. C. and a concentration of 1 g/dl in 98% concentrated sulfuric acid.The transparent copolyamide according to the present invention shows a sufficient resistance to alcohols, a sufficient resistance to boiling water and high moldability, therefore, is useful as the material for molded articles such as parts in automobiles, electronic and electric appliances and machines.

Abstract: A process for producing a polycarbonate resin having a viscosity-average molecular weight of from 9,000 to 50,000 by reacting at least one bisphenol compound with phosgene or a carbonate, characterized in that a phenol compound having the formula: ##STR1## wherein R is an alkyl group having from 5 to 7 carbon atoms, and R is located at the ortho- or para-position relative to the OH group, is used as a molecular weight modifier.

Abstract: A polycarbonate containing from 25 to 100% by weight, based on the total carbonate bond-constituting units, of carbonate bond-constituting units each containing at least one pendant aromatic group, and having an average molecular weight of from 9,500 to 14,000.

Abstract: An optical disc substrate made of a polycarbonate containing from 5 to 100% by weight, based on the total carbonate bond-constituting units, of carbonate bond-constituting units having the formula: ##STR1## wherein each of Y and Z is a hydrogen atom or an aliphatic hydrocarbon group having from 1 to 6 carbon atoms, and each of X and W is an aliphatic hydrocarbon group having from 1 to 6 carbon atoms.

Abstract: In a process for preparing polyolefin by polymerizing an olefin in the presence of a catalyst system combining an organo-aluminum compound and a titanium containing solid catalytic component prepared by mixing (a) a silanol compound (b) a Grignard reagent and (c) a titanium tetrahalide, the components (a) (b) or (c) or the reaction mixture of two or three components thereof is contacted with (d) one or more electron donor selected from the group consisting of amines, carboxylic acid amides, phosphines, phosphine oxides, phosphoric esters, phosphorous esters, phosphoric acid amides, ketones and carboxylic esters. The polyolefin having high isotactic index can be obtained.

Abstract: A process for producing a polyolefin characterized by polymerizing an olefin in the presence of a catalytic system composed of solid titanium trichloride, an organic aluminum compound, an aromatic hydrocarbon and a monocarboxylic acid ester having an olefinic double bond or an aromatic ring in the molecule thereof.

Abstract: A propylene-ethylene block copolymer in the presence of a catalyst comprises as main components, a solid titanium-containing catalytic component and an organoaluminum compound having the formulaAIR.sub.m.sup.1 Cl.sub.3-m(R.sup.1 represents a C.sub.1-20 hydrocarbon moiety; and m is 3.gtoreq.m>1.5) by producing a homopolymer of propylene or a propylene-ethylene copolymer by polymerizing propylene or both propylene and ethylene at a vapor phase propylene concentration of 90 mol % or higher based on the sum of propylene and ethylene in a first step and producing a propylene-ethylene block copolymer by copolymerizing propylene and ethylene at a vapor phase propylene concentration of less than 90 mol % based on the sum of propylene and ethylene in the presence of the polymer resulted in the first step and the catalyst in a second step is produced by newly adding an aluminum compound having the formulaAlR.sub.n.sup.2 X.sub.3-n(R.sup.2 represents a C.sub.

Abstract: Propylene is polymerized in the presence of a catalytic system of the type which comprises a solid titanium trichloride-based complex serving as a catalyst, said complex having an atomic ratio of aluminum to titanium in the range of below 0.15:1 and containing a complexing agent, and an organic aluminum compound of the general formula, AlR.sup.1.sub.n Cl.sub.3-n wherein R.sup.1 represents an n-propyl group or an n-hexyl group and n is a value of 1.95-2.10. The catalytic system may further comprise an electron-donor compound as a third catalytic component.

Abstract: A propylene-ethylene block copolymer is produced in the presence of a catalytic system essentially comprising an organoaluminum compound and a solid titanium trichloride catalytic complex having an atomic ratio of Al to Ti of less than 0.15 and having a complexing agent in two stages of polymerization;(a) a first stage for polymerizing propylene in the presence of a liquid propylene and hydrogen to produce a propylene homopolymer having a melt flow index of 1 to 150 at a ratio of 70 to 95% by weight based on a total of polymers; and(b) a second stage for copolymerizing propylene and ethylene in the presence of hydrogen and a liquid propylene at a concentration of propylene in vapor phase based on a total of propylene and ethylene in vapor phase of 50 to 85 mol. % and at a concentration of hydrogen in vapor phase based on a total of propylene and ethylene in vapor phase of 0.5 to 30 mol %, to produce ethylene-propylene copolymer having a melt flow index of 10.sup.-7 to 0.

Abstract: A fine solid titanium trichloride is used as a catalyst for a polymerization of an .alpha.-olefin. The solid titanium trichloride is produced by precipitating it at lower than 150.degree. C. from a liquid titanium trichloride complex in the presence of an ester having the formula ##STR1## wherein R.sup.1 and R.sup.2 respectively represent a hydrocarbon moiety and total carbon atoms of R.sup.1 and R.sup.2 are 10 or more.

Abstract: Propylene is polymerized in the presence of a catalytic system of the type which comprises a solid titanium trichloride-based complex serving as a catalyst, said complex having an atomic ratio of aluminum to titanium in the range of below 0.15:1 and containing a complexing agent, and an organic aluminium compound of the general formula, AlR.sub.n.sup.1 Cl.sub.3-n wherein R.sup.1 represents an n-propyl group or an n-hexyl group and n is a value of 1.95-2.10. The catalytic system may further comprise an electron-donor compound as a third catalytic component.

Abstract: In a process for preparing polyolefin by polymerizing an olefin in the presence of a catalyst system combining an organoaluminum compound and a titanium-containing solid catalytic component prepared by mixing (a) water and/or a hydroxy compound, (b) a Grignard reagent and (c) a titanium tetrahalide, the components (a) (b) or (c) or the reaction mixture of two or three components thereof is contacted with (d) one or more electron donor selected from the group consisting of amines, carboxylic acid amides, phosphines, phosphine oxides, phosphoric esters, phosphorous esters, phosphoric acid amides, ketones and carboxylic esters. The polyolefin having high isotactic index can be obtained.

Abstract: Solid titanium trichloride in the form of fine granules having low aluminum compound content, which is suitable as a catalyst for polymerization of .alpha.-olefins, especially, propylene is obtained as a precipitate by heating liquefied titanium trichloride in the presence of a liberating agent, and separating the thus formed precipitate. The liquified titanium trichloride is preferably prepared with an reducing titanium tetrachloride by organic aluminum compound in the presence of ether and hydrocarbon.

Abstract: Solid titanium trichloride in the form of fine granules having low aluminum compound content, which is suitable as a catalyst for polymerization of .alpha.-olefins, especially, propylene is obtained as a precipitate by heating liquefied titanium trichloride in the presence of a liberating agent, and separating the thus formed precipitate. The liquefied titanium trichloride is preferably prepared with an reducing titanium tetrachloride by organic aluminium compound in the presence of ether and hydrocarbon.