Mitsubishi Gas Chemical Company, Inc.

Tatsuya Yamauchi

Yasuhiro Kushida

Yoshikazu Shima

Yuuichi Sugano

Hideyuki Sato

Junichi Edahiro

Takami Morishita

The present invention provides a method for producing a polyester resin comprising dicarboxylic acid units and diol units, wherein at least a portion of the diol units is a diol unit having a cyclic acetal skeleton, the method comprising specific steps (1) to (4-2).

Method for producing polyester resin

A safe and stable production method of a hydrogenated polymer having high transparency, which is a production method of a hydrogenated polymer by hydrogenating aromatic rings of an aromatic vinyl compound-(meth)acrylate copolymer, in which (1) a solvent solution of the copolymer is added to a reactor, which has a solvent and a supported palladium catalyst charged therein, under a hydrogen atmosphere at a rate of from 0.01 to 15 g/hour in terms of the copolymer per unit mass (g) of the supported palladium catalyst, thereby performing hydrogenation reaction, and then such an operation is performed repeatedly that (2) a hydrogenated polymer is obtained from 30 to 90% by mass of the resulting reaction mixed solution, and a fresh solvent solution of the copolymer is added to the reactor, in which the residual reaction mixed solution is left, or to which the residual reaction mixed solution is returned, at a rate of from 0.01 to 15 g/hour in terms of the copolymer per unit mass (g) of the supported palladium catalyst, thereby performing hydrogenation reaction.

Process for production of nucleus-hydrogenated aromatic vinyl/(meth)acrylate copolymers

A process for producing a hydrogenated polymer, which includes a step of hydrogenating aromatic rings of an aromatic vinyl compound&#x2014;(meth)acrylate copolymer. In the process, the copolymer having a ratio, A/B, of from 0.25 to 4.0 (A is a molar number of constitutional units derived from the (meth)acrylate monomer, and B is a molar number of constitutional units derived from the aromatic vinyl monomer) is hydrogenated in a solvent in the presence of a catalyst which is composed of zirconium oxide supporting palladium. By the process, a highly transparent, hydrogenated polymer is stably and rapidly produced for a long period of time or repeatedly.

Process for producing hydrogenated polymers

In the production of a nuclear-hydrogenated polymer, the hydrogenation of an aromatic vinyl compound&#x2014;(meth)acrylate copolymer is conducted in a mixed solvent comprising an ester compound and an alcohol compound in the presence of a catalyst. By this method, a highly transparent nuclear-hydrogenated polymer is produced safely, stably and quickly, even when the degree of nuclear-hydrogenation is low.

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Niigata, Japan

Tatsuya Yamauchi