Mitsubishi Chemical Corporation

Nitto-denko Corporation

Mitsubishi Plastics, Inc.

Michiaki Fuji

Tomohiko Tanaka

Masanori Yamamoto

Shingo Namiki

Minako Akita

Nao Murakami

Takashi Shimizu

Masashi Yokogi

Masaki Yamamoto

Kazuya Tanaka

Kouichirou Taniguchi

Tomoko Maeda

Hisatoshi Uehara

Kenichi Satake

Haruo Sasaki

Hiroyuki Hayashi

Takafumi Nakagawa

Yuuichi Nishida

Kiminori Kawakami

Kazuki Fukumoto

Masahi Yokogi

Naoya Kageyama

Takahiro Fukumoto

Takayoshi Takahashi

Disclosed herein is a process for producing a transparent film, including the step of stretching a film in at least one direction under a condition(s) that satisfies an expression (5):200%/min&#x2264;[stretching speed(strain rate)]&#x2264;1,200%/min&#x2003;&#x2003;(5),wherein the film comprises a polycarbonate resin containing at least a constitutional unit derived from a dihydroxy compound (A) that has a bonded structure represented by a structural formula (1): in which no hydrogen atom is bonded to the oxygen atom contained in the structural formula (1).

Polycarbonate resin film, and transparent film and process for producing the same

The present invention relates to a polycarbonate resin containing, in the molecule, a structure represented by the following formula (1): wherein X has a structure represented by any one of the following formula (2) to (4): wherein each of Rto Rindependently represents a hydrogen atom or an organic group having a carbon number of 1 to 30; the organic group may have an arbitrary substituent, and any two or more members of Rto Rmay combine with each other to form a ring, which is excellent in heat resistance, transparency, light resistance, weather resistance and mechanical strength.

Polycarbonate resin

A polycarbonate resin film of the present invention is formed from a polycarbonate resin which contains at least a constitutional unit derived from a dihydroxy compound having a bonded structure represented by the following structural formula (1) and satisfies the following expression (2) when subjected to a tensile test at a standard stretching temperature for the polycarbonate resin and at a pulling speed (strain rate) of 1,000%/min.[Chem. 1]CH&#x2014;O&#x2003;&#x2003;(1)(No hydrogen atom is bonded to the oxygen atom contained in the structural formula (1).)0.9&#x2266;[(lower yield stress in tension)/(upper yield stress in tension)]&#x2266;1&#x2003;&#x2003;(2).

The invention is to provide polycarbonate resins having excellent light resistance, transparency, hue, heat resistance, thermal stability, and mechanical strength and to provide processes for efficiently and stably producing a polycarbonate resin which stably shows those performances. The invention includes: polycarbonate resins which at least contain structural units derived from a dihydroxy compound having the portion represented by formula (1) as part of the structure thereof and which have specific properties; and processes for producing the polycarbonate resins,CH&#x2014;O&#x2003;&#x2003;(1)where the case where the portion represented by formula (1) is part of &#x2014;CH&#x2014;O&#x2014;H is excluded.

Polycarbonate resins and processes for producing the same

The problem to be solved by the present invention is to provide a polycarbonate copolymer containing a plant-derived raw material, which is excellent in the mechanical strength and heat-resistant and assured of small refractive index, large Abbe number, small birefringence and excellent transparency. The present invention provides a polycarbonate copolymer containing a constitutional unit derived from a dihydroxy compound represented by the following formula (1) and a constitutional unit derived from an alicyclic dihydroxy compound, wherein the Abbe number is 50 or more and the 5% thermal reduction temperature is 340&#xb0; C. or more; and a method of producing this polycarbonate copolymer by reacting a dihydroxy compound represented by the following formula (1) and an alicyclic hydroxy compound with a carbonic acid diester in the presence of a polymerization catalyst. 

Polycarbonate copolymer and method of producing the same

The invention provides polycarbonate resins which are excellent in terms of light resistance, transparency, hue, heat resistance, thermal stability, and mechanical strength. The invention relates to a polycarbonate resin composition containing: a polycarbonate resin at least containing structural units derived from a dihydroxy compound having the portion represented by the following formula (1) as part of the structure thereof; and a bluing agent. The invention further relates to a polycarbonate resin composition including: a polycarbonate resin (A) containing structural units derived from a dihydroxy compound represented by the following formula (2) as part of the structure thereof; and a bluing agent.CH&#x2014;O&#x2003;&#x2003;(1)The case where the portion represented by the general formula (1) constitutes &#x2014;CH&#x2014;O&#x2014;H is excluded. 

Polycarbonate resin compositions and molded articles

The invention is to provide polycarbonate resins having excellent light resistance, transparency, hue, heat resistance, thermal stability, and mechanical strength and to provide processes for efficiently and stably producing a polycarbonate resin which stably shows those performances. The invention includes: polycarbonate resins which at least contain structural units derived from a dihydroxy compound having the portion represented by the following general formula (1) as part of the structure thereof and which have specific properties; and processes for producing the polycarbonate resins.[Chem. 1]CH&#x2014;O&#x2003;&#x2003;(1)(The case where the portion represented by general formula (1) is part of &#x2014;CH&#x2014;O&#x2014;H is excluded.)

A subject for the invention relates to processes for producing a polycarbonate containing a plant-derived starting material and to molded articles thereof, the polycarbonate having excellent mechanical strength, heat resistance, a low refractive index, a large Abbe number, low birefringence, and excellent transparency. The invention relates to a process for producing a polycarbonate which includes a step in which one or more dihydroxy compounds including a dihydroxy compound having at least one linking group &#x2014;CH&#x2014;O&#x2014; in the molecule thereof are reacted with a carbonic acid diester in the presence of a polymerization catalyst, wherein the dihydroxy compound having at least one linking group &#x2014;CH&#x2014;O&#x2014; in the molecule thereof has a formic acid content lower than 20 ppm. The invention further relates to a molded article constituted of a polycarbonate or a composition of the polycarbonate, the polycarbonate being a polycarbonate which contains constituent units derived from a dihydroxy compound having at least one linking group &#x2014;CH&#x2014;O&#x2014; in the molecule thereof and has an Abbe number of 50 or larger and a 5% weight loss temperature of 340&#xb0; C. or higher.

Processes for producing polycarbonate and molded polycarbonate articles

The present invention relates to a polycarbonate resin composition (X) which includes a polycarbonate resin (A) and an aromatic polycarbonate resin (B), the polycarbonate resin (A) including a constitutional unit derived from a dihydroxy compound (a) having, as part of the structure thereof, a site represented by the following formula (1) and a constitutional unit derived from a dihydroxy compound (b) of an aliphatic hydrocarbon, wherein the proportion of the constitutional unit derived from the dihydroxy compound (b) of an aliphatic hydrocarbon based on all constitutional units each derived from a dihydroxy compound in the polycarbonate resin (A) is 45% by mole or more. (The case where the site represented by the formula (1) is part of &#x2014;CH&#x2014;O&#x2014;H is omitted.)

Polycarbonate resin composition, and molded object, film, plate, and injection-molded article obtained by molding the same

A subject for the invention is to provide a polycarbonate having excellent mechanical strength, heat resistance, a low refractive index, a large Abbe number, reduced birefringence, and excellent transparency. The invention relates to a polycarbonate characterized by being obtained by subjecting one or more dihydroxy compounds including a dihydroxy compound having at least one linking group &#x2014;CH&#x2014;O&#x2014; in the molecule thereof to melt polycondensation with a carbonic acid diester, and by having a reduced viscosity of from 0.40 dL/g to 1.70 dL/g and a formic acid content lower than 5 ppm by weight.

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Mie, Japan

Michiaki Fuji