摘要:
A porous polymer of propylene optionally containing up to 15% by weight of an alpha-olefins of formula CH2═CHR wherein R is a hydrogen atom or a C2-C10 alkyl radical having the following characteristics: a) in the Temperature Rising Elution Temperature analysis (TREF) a fraction eluted at a temperature range front 25° C. to 97° higher than 20% of the total polymer eluted; and b) a pore volume (determined by mercury absorption) greater than 0.45 cc/g.
摘要:
A process for preparing porous olefin polymers comprising bringing into contact in a polymerization reactor, at a temperature T1, one or more olefins of the formula (I) CH2═CHR1, R1 being hydrogen, a C1–C20-alkyl or a C6–C12-aryl group, with a catalyst obtained by reacting a solid catalyst component in the form of spheroidal particles comprising a compound of Ti or V not containing metal-π bonds and a Mg halide, optionally containing one or more electron donor compounds, with an aluminum-alkyl (Al-alkyl) compound, then raising the temperature up to the polymerization temperature, said process being characterized in that: a) if the temperature T1 is lower than 40° C., the temperature is raised up to the polymerization temperature is such a way that, for a time of at least one minute after the introduction temperature in such a way that, for a time of at least one minute after the introduction of the catalyst system into the reactor, the temperature of the reaction T2 fulfills the following condition of formula (II) wherein m is the time expressed in minutes employed for reaching the temperature T2; or b) if temperature T1 is 40° C. or higher, the reactor is maintained for a time of at least one minute at a temperature of at least 40° C.
摘要:
A process for the preparation of heterophasic elastomeric polymer comprising the step of polymerizing ethylene, an alpha-olefin CH2=CHL, where L is an alkyl, cycloalkyl or aryl radical with 1-10 carbon atoms and a non-conjugated diene in the presence of a catalyst system comprising a transition metal catalyst component supported on a porous alpha-olefin polymer, characterized in that at least part of the diene is impregnated on the porous alpha-olefin polymer.
摘要:
A process for the preparation of heterophasic elastomeric polymer comprising the step of polymerizing ethylene, an alpha-olefin CH2═CHL, where L is an alkyl, cycloalkyl or aryl radical with 1–10 carbon atoms and a non-conjugated diene in the presence of a catalyst system comprising a transition metal catalyst component supported on a porous alpha-olefin polymer, characterized in that at least part of the diene is impregnated on the porous alpha-olefin polymer.
摘要:
Described is a thermoplastic composition including: (A) 10 to 99% by weight of a propylene polymer optionally containing from 0.1 to 5% by moles of units derived from an olefin of the formula CH2═CHR, R being hydrogen, a C2-C20-alkyl or a C6-C12-aryl group, having the following characteristics: 50
摘要:
Process for the preparation of ethylene copolymers comprising the copolymerization of ethylene with olefins CH2═CHR, in which R is a hydrocarbyl radical with 1-12 carbon atoms carried out in the presence of a catalyst comprising (i) a solid catalyst component comprising Mg, Ti, halogen and specific 1,3-diethers of formula (I) in which R is a C1-C10 hydrocarbon group, R1 is methyl or ethyl, optionally containing a heteroatom, and R2 is a C4-C12 linear alkyl optionally containing a heteroatom, and (ii) an organo-Al compound. The obtained copolymers are endowed with good comonomer distribution.
摘要:
A polyolefin composition, comprising: (A) from 5 to 95 parts by weight of a crystalline propylene polymer having an isotactic index greater than 80, selected from polypropylene homopolymer and propylene copolymers containing 0.5 to 15 mol % of ethylene and/or an α-olefin having 4 to 10 carbon atoms, and (B) from 5 to 95 parts by weight of an ethylene/α-olefin copolymer containing from 35 to 70% by weight of ethylene, from 30 to 65% by weight of an olefin CH2═CHR, in which R a hydrocarbyl radical with 1-12 carbon atoms, and from 0 to 10% of a polyene characterized by (i) a Molecular Weight Distribution expressed by Mw/Mn of higher than 3, (ii) a content of 2-1 regioinvertions of the α-olefin units of lower than 5% and (iii) a value of Shore A and content by weight of ethylenic units, calculated on the basis of the whole polymer, such that the point defined by such values falls below the curve defined by the following equation: Y=0.0438X2-4.1332X+A where Y is the value of the Shore A, X is the weight percentage of ethylene units in the polymer calculated by NMR and A is 145.
摘要翻译:一种聚烯烃组合物,其包含:(A)5至95重量份的全同立构指数大于80的结晶丙烯聚合物,其选自聚丙烯均聚物和含有0.5至15摩尔%乙烯和/或α-烯烃的丙烯共聚物, 具有4至10个碳原子的烯烃,和(B)5至95重量份的含有35至70重量%乙烯的乙烯/α-烯烃共聚物,30至65重量%的烯烃CH 2, 其中R 1具有1-12个碳原子的烃基和0至10%的多烯,其特征在于(i)由Mw / Mn表示的分子量分布高于3 ,(ii)α-烯烃单元的2-1区域转换的含量低于5%,(iii)肖氏A值和基于整个聚合物计算的烯属单元的重量含量,使得 由这些值定义的点低于由以下等式定义的曲线:<?in-line-formula description =“In-li “公式”end =“lead”?> Y = 0.0438X <2> -4.1332X + A <?in-line-formula description =“In-line Formulas”end =“tail”?> where Y是肖氏A的值,X是通过NMR计算的聚合物中乙烯单元的重量百分比,A是145。
摘要:
Polyolefin compositions particularly suitable for cast film, exhibiting heat sealability, retortability, low haze and stiffness, comprising: 1) 75-85% of a propylene homopolymer or copolymer of propylene with ethylene and/or one or more C4-C10 α-olefin(s), the homopolymer or copolymer having melting temperature equal to or higher than 150° C., 2) 15-25% of a copolymer of ethylene with one or more C4-C10 α-olefin(s) containing from 20 to 30% of said C4-C10 α-olefin(s); said composition having MFR (at 230° C., 2.16 kg) of from 5-10 g/10 min, the total content of ethylene of from 10 to 20%, the total content of C4-C10 α-olefin(s) of from 2 to 8%, the ratio XStot/XSm of the total fraction soluble in Xylene at room temperature to the fraction soluble in Xylene at room temperature of the matrix component (1) of from 5 to 15, and the value of the intrinsic viscosity of the total fraction soluble in Xylene at room temperature (XSIVtot) of 1.5 dl/g or less.
摘要:
Process for the preparation of ethylene copolymers comprising the copolymerization of ethylene with olefins CH2═CHR, in which R is a hyrdocarbyl radical with 1-12 carbon atoms carried out in the presence of a catalyst comprising (i) a solid catalyst component comprising Mg, Ti, halogen and specific 1,3-diethers of formula (I) in which R is a C1-C10 hydrocarbon group, R1 is methyl or ethyl, optionally containing a heteroatom, and R2 is a C4-C12 linear alkyl optionally containing a heteroatom, and (ii) an organo-Al compound. The obtained copolymers are endowed with good comonomer distribution.
摘要:
A low loss snubber provides stress relief for a first controllable semiconductor switch. The low loss snubber comprises a capacitor in series with a diode. This series combination is connected across the first switch, with the diode poled to conduct current to charge the capacitor when the first switch turns off. The low loss snubber further comprises an energy retrieval converter for removing energy from the capacitor when the first switch turns on. The energy retrieval converter has a second controllable semiconductor switch which is repeatedly turned on and off responsive to the first switch remaining in the closed position. An inductor means is in series with the second switch and the capacitor is provided for transferring the energy stored in the inductor means to an external load when the second switch is open.