摘要:
A propylene-ethylene-butene block copolymer is provided which includes from 60 to 85% by weight of a polypropylene portion and from 15 to 40% by weight of a propylene-ethylene-butene random copolymer portion, wherein the copolymer satisfies the requirements (1) and (2) given below. In addition, a molded article including such a propylene-ethylene-butene block copolymer is provided.(1) The random copolymer portion includes a propylene-ethylene random copolymer component (EP) and a propylene-ethylene-butene random copolymer component (EPB) and the copolymer component (EP) has an intrinsic viscosity of from 1.5 to 8 dl/g and an ethylene unit content of from 20 to 50% by weight, and the copolymer component (EPB) has an intrinsic viscosity of from 0.5 to 8 dl/g, an ethylene unit content of from 47 to 77% by weight and a butene unit component of from 3 to 33% by weight and the total of the ethylene unit content and the butene unit content is from 50 to 80% by weight.(2): The propylene-ethylene-butene block copolymer has a melt flow rate of from 5 to 120 g/10 min.
摘要:
There is provided a process for producing an olefin polymer, which comprises a step of polymerizing an olefin in a gas phase in the presence of a homogeneous solid catalyst having a content of particles having a particle size of not more than 180 &mgr;m of not more than 15% by weight based on 100% by weight of the total weight of the homogeneous solid catalyst.
摘要:
A propylene-ethylene random copolymer prepared by copolymerizing propylene with ethylene in the substantial absence of a liquid medium with a catalyst system comprising:(A) a solid catalyst component containing magnesium, titanium, a halogen and a first electron donor as an essential component,(B) an organoaluminum compound and(C) a second electron donor compound, wherein an ethylene content (E) of the copolymer is from 3.5 to 7.0% by weight, and wherein a content of a xylene-soluble portion at 20.degree. C. (D) of the copolymer satisfies the relationship D.ltoreq.E+2.0 (% by weight). Films of the copolymer have an excellent appearance (little bleed whitening) and an excellent balance between low-temperature heat-sealing property and rigidity.
摘要:
A polypropylene laminated film containing a crystalline polypropylene layer and, laminated on at least one side of the layer of the crystalline polypropylene, a layer of a copolymer of propylene and at least one .alpha.-olefin of from 4 to 10 carbon atoms having a specific composition, melt flow rate and molecular weight distribution in which the .alpha.-olefin content in the cold xylene soluble portion of the random copolymer is less than 1.7 times the .alpha.-olefin content in the copolymer and the random copolymer satisfies the mathematical expression,B.ltoreq.1.05A-10,wherein A is a weight percentage of the content of said at least one .alpha.-olefin having from 4 to 10 carbon atoms in the random copolymer and B is a weight percentage of the cold xylene soluble portion in the random copolymer, is superior in low temperature heat sealability and hot tack property and moreover has a good transparency, blocking resistance and printability, wherein the random copolymer is obtained by gas phase polymerization substantially in the absence of a liquid medium, and using a catalyst system comprising (i) a solid catalyst component containing magnesium, titanium and a halogen as essential constituents, (ii) an organoaluminum compound and (iii) an electron donative compound.
摘要:
A polypropylene composition comprising a melt-kneaded polyprolylene composition obtained, using Zieglar-Natta catalyst, by polymerizing a monomer comprising propylene to form a polymer comprising polypropylene (component A) in amount of from 60 to 80% by weight to the total polymer amount in substantially the absence of an inert solvent in a 1st step and then polymerizing a mixture of ethylene content of from 20 to 50% by weight (component B) in a vapor phase to form an ethylene-propylene copolymer (component B) in amount of from 20 to 40% by weight to the total polymer amount in a 2nd step, said polypropylene composition being such that the intrinsic viscosity of component B ([.eta.]B) is at least 2.0 dl/g and the ratio ([.eta.]B/[.eta.]A) of the intrinsic viscosity of the component B to the intrinsic viscosity of the component A ([.eta.]A) is 1.8 or less and the melt flow rate of the polypropylene composition after melt-kneaded being 0.5 to 10 g/10 minutes.
摘要:
A polypropylene laminate film comprising a crystalline polypropylene layer having laminated on at least one surface thereof a copolymer which is a random copolymer of propylene, ethylene, and an .alpha.-olefin having at least 4 carbon atoms, the copolymer being obtained by a vapor-phase polymerization using a catalyst system comprising a solid catalyst component containing magnesium, titanium, and a halogen, an organoaluminum compound, and an electron donative compound in substantially the absence of a liquid medium, and satisfying the following requirements (1) to (7):(1) the ethylene content of the copolymer is from 3.0 to 7.0% by weight,(2) the content of the .alpha.-olefin having at least 4 carbon atoms of the copolymer is from 2.0 to 6.0% by weight,(3) the ratio of the ethylene content to the content of the .alpha.-olefin having at least 4 carbon atoms in the copolymer is at least 1.0,(4) the melt flow rate of the copolymer is 10 g/10 minutes or less,(5) the ratio of the weight average molecular weight to the number average molecular weight of the copolymer is 4.5 or less,(6) the melting point of the copolymer is 135.degree.C. or less, and(7) the amount of the n-hexane-soluble components in the copolymer is less than 5.5% by weight.
摘要:
A process for producing ethylene-propylene block copolymer which comprises(1) The first step of reacting propylene or a mixture of propylene and ethylene in the presence of a catalyst composed essentially of(A) a solid catalyst component containing magnesium, titanium and a halogen as the indispensable ingredients,(B) an organoaluminum compound, and(C) a silicon compound (1) represented by the formula R.sup.1 R.sup.2 Si(OR.sup.3).sub.2, wherein R.sup.1 is an alicyclic hydrocarbon group of 5-20 carbon atoms and R.sup.2 and R.sup.3 are each independently a hydrocarbon group of 1-20 carbon atoms, to form a propylene homopolymer portion or an ethylene-propylene copolymer portion having an ethylene content of 3% by weight or less, in an amount corresponding to 50-95% by weight of the total block copolymer amount, and(2) the second step of reacting a mixture of ethylene and propylene with the polymer portion obtained in the first step in the presence of the aforesaid catalyst composed essentially of the components (a), (b) and (c) and in the additional presence of a silicon compound (2) represented by the formula R.sup.4.sub.a Si(OR.sup.5).sub.4-a, wherein R.sup.4 and R.sup.5 are each independently a hydrocarbon group of 1-20 carbon atoms and a is a number satisfying the equation 0.ltoreq.a
摘要:
High-Strength polypropylene fiber is obtained from polypropylene having incorporated therein from 0.05 to 10,000 ppm by weight of a vinylcycloalkane polymer. The disclosed fiber polypropylene has an intrinsic viscosity of from 0.5 to 2.5 dl/g as measured in a tetralin solution at 135.degree. C. and a ratio of weight average molecular weight to number average molecular weight of not more than 3.5/1.
摘要:
A process for the production of .alpha.-olefin block copolymer particles having excellent impact resistance at low temperature and excellent molding and processing characteristics, is disclosed. The process includes a two step gas phase polymerization procedure under specific conditions in the presence of a specific catalyst system.
摘要:
A process for producing a propylene-ethylene block copolymer by subjecting propylene and ethylene to three-step polymerization using a stereoregular polymerization catalyst, which comprises in the first step polymerizing propylene alone or a propylene/ethylene mixture so that the average ethylene/propylene reaction ratio is 6/94 or less, thereby polymerizing 60 to 95% by weight of the total polymerization amount, in the second step polymerizing a propylene/ethylene mixture so that the average ethylene/propylene reaction ratio is 25/75 to 67/33, thereby polymerizing 1 to 20% by weight of the total polymerization amount, and in the third step polymerizing a propylene/ethylene mixture so that the average ethylene/propylene reaction ratio is 76/24 to 89/11, thereby polymerizing 4 to 35% by weight of the total polymerization amount, wherein in the second and third steps, ethylene alone is supplied thereby gradually decreasing the amount of propylene in the polymerization system from the first step to the succeeding steps.