Abstract: The present invention provides a dielectric ceramic composition, which is, in addition to having superior resistance to reduction during firing, superior capacitance temperature characteristics after firing and superior dielectric characteristics, also demonstrates an enhanced lifetime for insulation resistance. The present invention is a dielectric ceramic composition comprising 0.18 to 0.5 part by weight of Yb2O3, 0.6 to 1.5 parts by weight of MgO, 0.4 to 1.5 parts by weight of CaSiO3, 0.02 to 0.2 part by weight of WO3, 0.1 to 0.4 part by weight of MnCO3 and 0.02 to 0.2 part by weight of MoO3 based on 100 parts by weight of (BaO)m.TiO2 (wherein, m is from 0.990 to 0.995).

Abstract: The present invention provides a dielectric ceramic composition, which is, in addition to having superior resistance to reduction during firing, superior capacitance temperature characteristics after firing and superior dielectric characteristics, also demonstrates an enhanced lifetime for insulation resistance. The present invention is a dielectric ceramic composition comprising 0.18 to 0.5 part by weight of Yb2O3, 0.6 to 1.5 parts by weight of MgO, 0.4 to 1.5 parts by weight of CaSiO3, 0.02 to 0.2 part by weight of WO3, 0.1 to 0.4 part by weight of MnCO3 and 0.02 to 0.2 part by weight of MoO3 based on 100 parts by weight of (BaO)m.TiO2 (wherein, m is from 0.990 to 0.995).

Abstract: The present invention provides an aryl styrene-based polymer of a degree of polymerization of at least 5 having recurring units represented by the general formula ##STR1## in the formula, R.sup.1 to R.sup.5 each denote a hydrogen atom, halogen atom or substituent group containing at least either one kind of a carbon atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, selenium atom, silicon atom and tin atom and at least one of the R.sup.1 to R.sup.5 denotes an aryl group having a hydrogen atom, aryl group having a halogen atom or aryl group having a substituent group containing at least either one kind of a carbon atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, selenium atom, silicon atom and tin atom, of which the stereospecificity is a mainly syndiotactic configuration and a method for the preparation thereof as well as a styrene-based copolymer and a method for the preparation thereof.

Abstract: A process for producing a norbornene polymer consisting essentially of a repeating unit of the formula (I) ##STR1## wherein R.sup.1 to R.sup.12 are the same or different and are hydrogen, C.sub.1 -C.sub.20 hydrocarbon, or a group having a halogen, oxygen or nitrogen, R.sup.5 and R.sup.7 may combine to form a ring, and n is an integer of 0 or more; and having a weight average molecular weight as determined by GPC of 1.times.10.sup.5 to 1.times.10.sup.7. The process comprises polymerizing a norbornene monomer of the formula (II) ##STR2## wherein R.sup.1 to R.sup.12 are the same or different and are independently hydrogen, C.sub.1 -C.sub.20 hydrocarbon, or a substituent containing a halogen atom, an oxygen atom or a nitrogen atom; R.sup.5 and R.sup.

Abstract: The present invention provides a polyolefinic resin-coated carrier having a rough surface and containing a core material in a quantity of 90 or more % by weight. Said resin-coated layer may contain fine particles having a charge-controlling function and/or electrically conductive fine particles as additives.

Abstract: The present invention provides a carrier of a two component developer for developing electrostatic latent images comprising;a carrier core material comprising a magnetic particle,an irregular surface-coating layer formed by coating the carrier core material with polyolefinic resin, followed by heat treatment.

Abstract: The present invention provides fine particles comprising core particles and polyolefinic resin layers for composing an electrostatic latent image developer, characterized in that the polyolefinic resin layers are formed by polymerizing olefinic monomers on surfaces of the core particles.

Abstract: The present invention provides a polyolefinic resin-coated carrier having a rough surface and containing a core material in a quantity of 90 or more % by weight. Said resin-coated layer may contain fine particles having a charge-controlling function and/or electrically conductive fine particles as additives.

Abstract: A lip seal device for sealing the gap between a housing and a rotary shaft comprises a case surrounding the rotary shaft, a lip seal attached inside the case a, support for holding the lip seal on the outer circumferential portion thereof and a seal located on the outside circumferential surface of the case. The inner circumferential portion of the lip seal is curved toward the sealed fluid. The lip seal includes a sealing surface provided with an annular groove extending continuously in the circumferential direction of the rotary shaft so that the sealing surface has a first and second sealing portion, the contact pressure of the first sealing portion on the rotary shaft being lower than the contact pressure of the second sealing portion on the rotary shaft.

Abstract: A lip seal device for sealing the gap between a housing and a rotary shaft comprises a case surrounding the rotary shaft, a lip seal attached inside the case, support means for holding the lip seal on the other circumferential portion thereof and seal means located on the outside circumferential surface of the case. The inner circumferential portion of the lip seal is curved toward the sealed fluid. The lip seal includes a sealing surface provided with an annular groove extending continuously in the circumferential direction of the rotary shaft so that the sealing surface has a first and second sealing portion, the contact pressure of the first sealing portion on the rotary shaft being lower than the contact pressure of the second sealing portion on the rotary shaft.

Abstract: A lip seal device for sealing the gap between a housing and a rotary shaft comprises a case surrounding the rotary shaft, a plurality of lip seals fitted inside the case and including at least two lip seals, support means for holding the lip seals on the outer circumferential portions thereof and seal means located on the outside of the circumferential surface of the case. The inner circumferential portions of the lip seals are curved toward the sealed fluid and have a sealing surface in contact with the outside circumferential surface of the rotary shaft. The contact pressure of the lip seal furthest from the sealed fluid is lower than the contact pressure of the lip seal closest to the sealed fluid.

Abstract: A process for producing a polyethylene composition which comprises polymerizing ethylene in the presence of a catalyst comprising (A) a contact treatment product of (a) a high activity catalyst component and (b) a filler, and (B) an organoaluminum compound.This process has no need for a deashing step, i.e., a step to remove the catalyst after polymerization, since the catalyst has a remarkably high activity.In the polyethylene composition produced, the filler is dispersed uniformly and the separation of the filler from the polyethylene is scarcely observed.

Abstract: A process for the stereospecific polymerization of .alpha.-olefins which comprises polymerizing an .alpha.-olefin with a catalyst comprising (A) the reaction product of a magnesium compound and a titanium compound and (B) an organo-aluminum compound. Component (A) is prepared by reacting a (i) magnesium compound of the formula Mg(OR.sup.1).sub.n X.sup.1.sub.2-n wherein R.sup.1 contains from 1 to 10 carbon atoms and is an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group, X.sup.1 is a halogen atom, and n is a real number of from 1.0 to 2.0, with (ii) at least one halogen-containing compound selected from the group consisting of halogenated hydrocarbons, oxygen-containing halogenated hydrocarbons, halogenated thionyls, halogen-containing phosphorus compounds and halogen-containing nitrogen compounds, and (iii) an oxygen-containing titanium compound of the formula Ti(OR.sup.2).sub.4 wherein R.sup.

Abstract: A process for producing an improved titanium catalyst for use in the polymerization of olefins comprising heating a magnesium dialkoxide and an alcohol adduct of a magnesium dihalide to form a solid product, treating said solid product with an alcohol to form an alcohol treated solid product, and then reacting said alcohol treated solid product with a halogen-containing titanium compound. The reaction product of said alcohol treated solid product with the halogen-containing titanium compound may optionally be reacted with an organoaluminum compound. The products of the processes described in the preceding two sentences is an improved titanium catalyst which is generally used with an organoaluminum olefin polymerization cocatalyst.

Abstract: Ethylene is polymerized in the presence of a catalyst comprising: (A) the reaction product of a magnesium compound and titanium halide and (B) an organic aluminum compound wherein Component A is prepared by reacting magnesium dialkoxide with a halogen-containing silicon compound and an alcohol to provide a solid material and then reacting the solid material with titanium halide in the presence of an alkoxy-containing silicon compound.

Abstract: Block copolymers are produced by (i) polymerizing ethylene or propylene, or copolymerizing the same with another .alpha.-olefin of 2 to 7 carbon atoms in the presence of a Ziegler-type catalyst, and (ii) copolymerizing the resulting polymer or copolymer with a radical-polymerizable vinyl compound (e.g., methyl methacrylate) in the presence of an organic sulfoxide.

Abstract: Block copolymers of (i) a polymer of ethylene or propylene, or copolymer of ethylene or propylene with another .alpha.-olefin and (ii) a polymer of an acrylic ester or a methacrylic ester are formed by polymerizing (i) in the presence of a titanium halide and an organic aluminum compound, and then adding in order (a), (b) and (c) to copolymerize a product so obtained with (a) an acrylic ester or a methacrylic ester, in the presence of (b) an organic phosphorus compound or tertiary amine and (c) a benzyl halide, a ring-alkylated benzyl halide, a benzyl halide in which a methylene hydrogen is replaced with an alkyl or aryl group, or an alkyl halide.