Mitsui Petrochemical Industries, Ltd.

Yoshihisa Ushida

Norio Kashiwa

Hiroshi Mase

Akinori Toyota

Nobuki Hirai

Mamoru Kioka

Syuji Minami

Takao Ohno

Kiyoshi Odawara

Hiroyuki Nagayama

Yoshikatu Amimoto

Laminated ceramic devices useful as an actuator or other device responsive to electrostrictive effects or photoelectric effects are manufactured by a method which includes the steps of forming an internal electrode on each of a plurality of unbaked ceramic sheets. Each of the internal electrodes is provided with a notched area for defining a so-called future space. A plurality of the unbaked ceramic sheets is assembled to form a laminate whereby the notched areas defining the future spaces are alternately located on two different sides of the laminate with the alternate notched areas being vertically aligned. The assembled plurality of ceramic sheets is then fired and the internal electrodes baked to thereby definitively form spaces defined by the notched areas which define the so-called future or void spaces. The resulting formed spaces are thereby alternatively located on different sides of the laminate. The device is completed by connecting first and second groups of alternating internal electrodes with respective external electrodes arranged along the different sides opposite to the corresponding respective spaces. As a result, each of the external electrodes is separated from the group of alternating internal electrodes to which it is not electrically connected by the resulting corresponding spaces. As a result, the laminated ceramic device is not or is less subject to concentration of stress due to uneven distribution of strain caused by application of an electric field whereby the durability of the laminated ceramic device is improved.

Method of manufacturing a laminated ceramic device

As improved process for producing an olefin polymer or copolymer by using a novel catalyst composition composed of (A) a titanium catalyst component containing magnesium, titanium, halogen and an ester specified in claim 1, as an electron donor, (B) an organoaluminum compound and (C) a heterocyclic compound or a ketone specified in claim 1, as a third component. The combination parameter of the ester in (A) and the (C) component is new, and the process can give a highly stereospecific olefin polymer or copolymer in high yields.

Process for producing an olefin polymer or copolymer and catalyst

A piezoelectric ceramic is provided which comprises a perovskite-based solid solution represented by the formula:

Piezoelectric ceramics

The present invention relates to Perovskite ferroelectric ceramics comprising a Perovskite solid solution represented by the formula

Ferroelectric ceramics

The present invention relates to a ferroelectric ceramic material which is a Perovskite solid solution comprising a solid solution represented by the formula:

Ferroelectric ceramic material

The present invention relates to a ferroelectric ceramic material which is a Perovskite solid said solution comprising a solid solution represented by the formula

Ferroelectric ceramics represented by xPbTiO.sub.3 -yPbZrO.sub.3 -zPb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3 -mSrTiO.sub.3 -nSnO.sub.2 -pZnO-qBi.sub.2 O.sub.3 -rX wherein x,y,z,m,n,p,q and r represent amounts by mole, respectively, with the proviso that x+y+z being 1, Z is at least one oxide selected from the group consisting of Dy.sub.2 O.sub.3, Ta.sub.2 O.sub.5, and Y.sub.2 O.sub.3, and wherein x is from 0.25 to 0.50, y is from 0.05 to 0.70, z is from 0.05 to 0.70, m is from 0 to 0.10, n is from 0 to 0.04, p is from 0 to 0.04, q is from 0 to 0.02 and r is from 0.005 to 0.02. The disclosed ferroelectric ceramics have increased relative dielectric constant and/or electromechanical coupling factor, and are suitable for use as actuators.

A process for polymerizing or copolymerizing olefins, which comprises polymerizing or copolymerizing olefins in the presence of a catalyst composed of (A) a solid titanium catalyst component obtained by reacting (i) a titanium composition composed essentially of tetravalent titanium, magnesium, halogen and an electron donor or electron donor residue selected from the group consisting of organic acid esters, alkoxy groups and aryloxy groups with (ii) an organic silicon compound having an Si--O--C bond in the molecule in the presence of (iii) an organoaluminum compound, or by first treating the titanium composition (i) with the organoaluminum compound (iii) and then reacting it with the organic silicon compound (ii), until the amount of the electron donor or electron donor residue in the titanium composition (i) decreases from that before the reaction, thus including a part of the silicon compound in the titanium composition, and; (B) an organoaluminum compound.

Process for polymerizing or copolymerizing olefins

In a process for producing an olefin polymer or copolymer by polymerizing an alpha-olefin having at least 3 carbon atoms or copolymerizing such alpha-olefins with each other or such an alpha-olefin with up to 20 mole % of ethylene and/or a diene in the presence of a catalyst comprising (1) a solid titanium catalyst component having magnesium, halogen, titanium, phosphorus and a carboxylic acid ester and (2) an organometallic compound of a metal of Groups I to III of the Mendelejeff's periodic table; the improvement wherein said catalyst is composed of (A) the solid titanium catalyst component (1) in which the molar ratio of the phosphorus to the carboxylic acid ester is from about 0.05 to about 2 and which has a specific surface area of not less than about 40 m.sup.2 /g, (B) the organometallic compound (2), and (C) an electron donor; and a catalyst used for aforesaid process.

Process for producing olefin polymers or copolymers and catalyst therefor

This invention provides a process for producing spherical carrier particles for olefin polymerization catalyst, which comprises

Process for the production of spherical carrier particles for olefin

A process for polymerizing or copolymerizing .alpha.-olefins having at least 3 carbon atoms or copolymerizing .alpha.-olefins having at least 3 carbon atoms with not more than 50 mole % of ethylene in the presence of a catalyst composed of an organometallic compound of a metal of Groups I to III of the periodic table and a titanium catalyst component supported on a halogen-containing magnesium compound, said titanium catalyst component being a solid reaction product obtained by treating (i) a mechanically copulverized product of a halogen-containing compound and an organic acid ester with (ii) an organo-metallic compound of a metal of Groups I to III of the periodic table, and then reacting the resulting solid product with (iii) a titanium compound in the absence of mechanical pulverization.

Growing community of inventors

Chiba, Japan

Yoshihisa Ushida