Neste Oy

Neste Chemicals Oy

Optatech Oy

Opatatech Corporation

Erkki Halme

Salme Koskimies

Jukka Koskinen

Pekka Knuuttila

Vesa Niemi

Leila Lahtinen

Sigmund M Csicsery

Christer Bergstr&ouml;m

Kari Vahteristo

Raija Savolainen

Mikael Skrifvars

Mika Kapanen

Markku Laatikainen

Sergey Ivanchev

Leena Rantanen

Nina Byrdina

Jaana Rantanen

Jouni Kivi

Valery Pavlyuchenko

Mika Per&auml;l&auml;

Hanna Laamanen

Matti Lindstr&ouml;m

Disclosed is a method for the preparation of norbornene and substituted norbornene compounds via a Diels-Alder reaction, in which a cyclic diene is reacted with an olefinic compound in order to prepare a norbornene compound. According to the invention a cyclic diene is gradually added to react with an olefinic compound, in order to keep the concentration of the cyclic diene in the reaction mixture as low as possible during the reaction. It is possible to obtain a very pure product, high yield, short reaction time and high concentrations of the exo diastereomer with the method of the invention.

Method for preparing norbornene and substituted derivatives of norbornene

A method for the preparation of latexes with hollow polymer particles useful as opacifying agents. The process comprises the preparation of hollow polymer particle latex by emulsion copolymerization with water soluble initiator and anionic surfactant as follows: a) preparation of seed latex of copolymer containing methyl methacrylate and methacrylic acid; b) preparation of latex of highly carboxylated copolymer containing methyl methacrylate and a cross-linking agent and optionally a vinyl aromatic compound; c) using highly carboxylated latex synthesized at stage b) in the preparation of the intermediate shell comprising a copolymer of methyl methacrylate, acrylic acid ester, a cross-linking agent and optionally vinyl aromatic compound, said intermediate shell copolymer having a glass transition temperature below 80&deg; C.; d) swelling the particles prepared at stage c) by addition of volatile basic compound; e) preparation of a hard shell on the swollen expanded particles comprising a copolymer of vinyl aromatic compound, acrylonitrile and/or methyl methacrylate, and cross-linking agent, said hard shell having a glass transition temperature above 80&deg; C.; and f) optional preparation of an external shell.

Method for the preparation of hollow polymer particle latex

Manufacturing of 2,6-dimethylnaphthalene

Alkenyl substituted cyclic carboxyl acid anhydrides and their

Catalyst system for selective alkylation of toluene

The invention concerns a procedure for manufacturing short-chain linear .alpha.-olefines, in particular 1-butylene, selectively from ethylene. A nickel chelate in which the ligand is diphenyl (2-carboxymethyl) phosphine, diphenyl (2-carboxyethyl) phosphine, or an alkali metal salt of these, or an alkali metal salt of diphenyl (2-hydroxyethyl) phosphine, with or without a promoter, is used for a catalyst.

Procedure for manufacturing short-chain linear .alpha.-olefines from

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Helsinki, Finland

Erkki Halme