Kuraray Co., Ltd.

Masaji Kato

Kenichi Hamada

Kazushige Ishiura

Sachie Yaginuma

Tomohiro Ono

Naohiko Uchiumi

Yoshihiro Morishita

Hiroshi Oshima

Tatsufumi Watanabe

Kazunori Watanabe

Susumu Matsunaga

Jun Nagai

Tatsuo Morotomi

The present invention relates to a method of obtaining a (meth)acrylate-based polymer from a reaction solution containing the (meth)acrylate-based polymer, the method including (a) adding an acid to the reaction solution containing the (meth)acrylate-based polymer which is obtained by polymerizing a monomer composed mainly of a (meth)acrylate in a water-insoluble organic solvent in the presence of a metal compound, (b) washing the reaction solution to which the acid has been added by admixing water at 90&#xb0; C. or more, (c) separating the mixed solution of the reaction solution and water generated by the washing in (b) into an organic solvent solution layer and an aqueous solution layer, and (d) isolating each of the organic solvent solution layer and the aqueous solution layer in order to obtain the (meth)acrylate-based polymer from the isolated organic solvent solution layer.

Method of taking (meth)acrylic ester polymer out of liquid reaction mixture

A block copolymer is obtained by anionic polymerization, includes two or more polymer blocks A miscible with each other, and at least one (meth)acrylic ester polymer block B immiscible with the polymer blocks A, has a ratio [Mn(A)/Mn(A)] of 2 or more, wherein the ratio [Mn(A)/Mn(A)] is the ratio of the largest number average molecular weight [Mn(A)] to the smallest number average molecular weight [Mn(A)] among the polymer blocks A, has at least one block bonding including polymer block A-polymer block B-polymer block A, and has a total content of the polymer blocks A ranging from 20 wt % to 45 wt % based on the total mass of the block copolymer. This invention provides block copolymers having two or more polymer blocks A miscible with each other and at least one (meth)acrylic ester polymer block B immiscible with the polymer blocks A and exhibiting satisfactory flexibility, melt fluidity, moldability, coatability, mechanical properties, and other properties. The block copolymers of the present invention can yield molded articles having reduced anisotropy and surface stickiness and excellent mechanical properties and pressure-sensitive adhesive compositions having excellent adhesive properties.

Block copolymer

A process for the preparation of an acrylic acid ester polymer, includes carrying out polymerization of an acrylic acid ester or block copolymerization of an acrylic acid ester and another (meth)acrylic monomer in the presence of an organolithium compound and an organoaluminum compound represented by the following formula (I):AlRRR&#x2003;&#x2003;(I)wherein Rrepresents an alkyl group having at least 3 carbon atoms, an alkoxy group having at least 3 carbon atoms or an aryloxy group, Rand Reach independently represent an aryloxy group or may be coupled together to form an arylenedioxy group. The process makes it possible to heighten the reaction rate and living properties upon polymerization and heighten the block formation efficiency upon block copolymerization.

Preparation process of acrylic acid ester polymer

In anionic polymerization using an anionic polymerization initiator, a tertiary organoaluminum compound (A) having in the molecule thereof a chemical structure represented by a general formula: Al&mdash;O&mdash;Ar wherein Ar represents an aromatic ring, and at least one Lewis base (B) selected from the group consisting of an ether compound and a tertiary polyamine compound are caused to be present in the polymerization system. In this way, the polar monomer can be polymerized with a high polymerization initiation efficiency and a high living polymerization property and at a high polymerization rate even if the used polymerization initiator is suitable for industrial use and a relatively mild cooling condition or a temperature condition near room temperature is adopted as a polymerization temperature condition.

Anionic polymerization process, and process for producing a polymer by the anionic polymerization process

In anionic polymerization using an anionic polymerization initiator, a tertiary organoaluminum compound (A) having in the molecule thereof a chemical structure represented by a general formula: Al&mdash;O&mdash;Ar wherein Ar represents an aromatic ring, and at least one Lewis base (B) selected from the group consisting of a tertiary polyamine compound, are caused to be present in the polymerization system. In this way, the polar monomer can be polymerized with a high polymerization initiation efficiency and a high living polymerization property and at a high polymerization rate even if the used polymerization initiator is suitable for industrial use, and a relatively mild cooling condition or a temperature condition near room temperature is adopted as a polymerization temperature condition.

Growing community of inventors

Tsukuba, Japan

Masaji Kato