Nissan Chemical Industries Limited

Noriaki Koto

Kazumi Tsubaki

Toyohiko Abe

Kouichi Maeda

Hideo Suzuki

Takeo Moro

Kanji Otsuka

Joei Yukawa

Naotake Okada

Keiichi Kondo

A polyimide resin composed essentially of repeating units represented by the general formula: ##STR1## where R is a divalent aromatic hydrocarbon radical.

Polyimide resin from cyclobutane tetracarboxylic acid dianhydride

A process for producing chlorobenzene sulfochloride comprises adding a reaction mixture of chlorobenzene and chlorosulfonic acid to water or diluted sulfuric acid to decompose excess chlorosulfonic acid; driving off hydrogen chloride thereby generated, from the system; bringing the sulfuric acid concentration in the sulfuric acid layer upon completion of the decomposition to be from 60 to 90%; and then separating chlorobenzene sulfochloride. The process is characterized in that the excess chlorosulfonic acid is decomposed at a temperature of from 40.degree. to 85.degree. C. and the chlorobenzene sulfochloride is separated in a liquid state at a temperature of from 60.degree. to 80.degree. C.

Process for producing chlorobenzene sulfochloride

A process for producing a silver coated copper powder, characterized in that a metal silver is precipitated on the surface of a metal copper powder by means of a silver complex solution comprising a silver salt, an ammonium carbonate compound and ammonia water as essential components.

Process for the production of a silver coated copper powder and

A copolymer of ethylene and a C.sub.4 -C.sub.10 .alpha.-olefin at a content of 0.5 to 10 mol % is produced by forming a polymerization catalyst system by reacting a Grignard reagent with a chain or cyclic hydropolysiloxane having the unit

Process for producing copolymer of ethylene

Butene-1 is polymerized in the presence of a catalytic system comprising a solid catalytic component (A), a trialkylaluminum compound (B), an organic acid ester (C), and an organoaluminum compound (D) at a molar ratio of (D) to (B) ranging 0.1 to 10 wherein said solid catalytic component (A) is obtained by reacting a reaction product (a) of a Grignard reagent with a chain or cyclic hydropolysiloxane having the unit ##EQU1## (R.sup.1 represents an alkyl, aryl, aralkyl, alkoxy or aryloxy group; a is 0, 1 or 2; b is 1, 2 or 3 and a+b.ltoreq.3) with at least one compound having the formula

Process for producing polybutene-1

A powdery isotactic polyolefin having high isotactic characteristic and high bulk density and a narrow size distribution is produced by forming a polymerization catalyst system by reacting a Grignard reagent with a chain or cyclic hydropolysiloxane having the unit ##EQU1## (R.sup.1 represents an alkyl, aryl, aralkyl, alkoxy or aryloxy group; a is 0, 1 or 2; b is 1, 2 or 3 and a+b.ltoreq.3) to form a reaction product (a); reacting the reaction product (a) with at least one compound having the formula

Process for producing powdery isotactic polyolefin

An improvement is disclosed in a process for preparing a polyphosphonate which comprises polycondensing an aromatic diol having the formula (I) - (IV) ##SPC1## wherein Z represents chlorine or bromine atom or a lower alkyl group and m represents 0 or an integer of from 1 to 4 and n represents 0 or an integer of from 1 to 3; Y represents an alkylene group, cycloalkylene group, sulfonyl group, carbonyl group or oxygen atom; with a dihalide or arylphosphonic or thiophosphonic acid having the formula (V) ##SPC2## wherein A represents oxygen or sulfur atom; X represents chlorine or bromine atom; Z represents chlorine or bromine atom or a lower alkyl group; and 1 represents 0 or an integer of from 1 to 5, wherein the improvement comprises maintaining a solution of the polyphosphonate at a temperature such that solid polyphosphonate is produced after flashing; and then evaporating all or a part of the solvent from the solution by flashing whereby a porous solid polyphosphonate is formed.

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Ichihara, Japan

Noriaki Koto