Mitsubishi Gas Chemical Company, Inc.

Mitsubishi Gas Chemical, Inc.

Shojiro Kuwahara

Masahiro Kurokawa

Takeshi Hirokane

Tsuyoshi Ikeda

Nobuyuki Koike

Yasushi Higuchi

Shinichi Hieda

Tadashi Kawabata

Tomohito Oyama

Nobuya Saegusa

Koshi Koide

Takamasa Kawashima

A thermoplastic transparent resin which is produced by hydrogenating 70% or more of aromatic double bonds of a copolymer. The copolymer is produced by polymerizing a monomer composition containing at least one (meth)acrylic ester monomer and at least one aromatic vinyl monomer and has a molar ratio (A/B) of from 1 to 4 wherein A is a molar amount of a constitutional unit derived from the (meth)acrylic ester monomer and B is a molar amount of a constitutional unit derived from the aromatic vinyl monomer. The thermoplastic transparent resin is suitable for the production of a molded article such as optical article having a good color tone because molding defect is less produced.

Thermoplastic transparent resin

The present invention relates to a polyester film produced by melt-extruding a polyester composed of a dicarboxylic acid unit and a diol unit, wherein 1 to 80 mol % of the diol unit is a unit containing a cyclic acetal skeleton, and the polyester film has an in-plane retardation of 20 nm or less at a wavelength of 550 nm. The polyester film is an optically isotropic polyester film which is easily produced by an extrusion-molding method and has an economical advantage. The polyester film is useful for production of optical members or optical products such as phase difference films, protective films for polarizing plates, light diffusion films, lens sheets, anti-reflection films and optical information recording media.

Polyester film, process for producing the same and use thereof

Disclosed is an acrylic syrup containing a vinyl monomer (A) of methyl methacrylate and a polymerized solid component (B) which is a high polymer of said vinyl monomer and has a weight average molecular weight of from 30,000 to 2,000,000 as measured by the GPC and a viscosity at 25&#xb0; C. of from 0.1 to 50 Pa&#xb7;s, wherein at least part of said polymerized solid component (B) is a grafted rubber obtained by graft-polymerizing said vinyl monomer with a rubbery polymer, and said grafted rubber has a large branching coefficient. The acrylic resin molded articles obtained from the acrylic syrup exhibit excellent impact resistance.

Acrylic syrup and method of producing the same

Disclosed is a method of producing a powdery coating material by using: a curable polyester resin (A) having a hydroxyl group and/or a carboxyl group at the terminals thereof, and further having a number average molecular weight of from 1,000 to 30,000, a glass transition temperature of from 30 to 100&#xb0; C.; a curing agent (B) which is solid at normal temperature and is capable of being reacted with the hydroxyl group or the carboxyl group of the curable polyester resin (A); and a solvent (C) having a boiling point under normal pressure of from 50 to 130&#xb0; C.; and comprising a step of kneading the curable polyester resin (A), the curing agent (B) and the solvent (C) under condition in which at 50 to 130&#xb0; C., not less than 20% by weight of the curing agent (B) is dissolved in the solvent and, then, vapor-removing the solvent (C) under a reduced pressure.

Method of producing polyester powdery coating material

In the invention, a polyester resin comprising dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process comprising an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a basic compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.

Process for producing polyester resins

In the invention, a polyester resin having dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process including an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a titanium compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.

Polyester resin composition (C) comprises polyester resin (A), which comprises polyester resin (l) comprising a diol unit having a cyclic acetal structure (CA) and a dicarboxylic acid unit having no CA, polyester resin (m) comprising a dicarboxylic acid unit having CA and a diol unit having no CA and/or polyester resin (n) comprising a diol unit having CA and a dicarboxylic acid unit having CA, and polyester resin (B) having no CA. The sum of the fraction of the dicarboxylic acid unit having CA in the entire dicarboxylic acid unit and the fraction of the diol unit having CA in the entire diol unit in composition (C) is 0.05% by mole or greater. The polyester resin compositions are excellent in transparency, melt viscoelasticity, heat resistance and moldability, and exhibit a samll crystallization rate.

Polyester resin composition

Acrylic syrup and method of producing same

Disclosed is a method of producing a powdery coating material by using a curable acrylic resin (A) having a number average molecular weight of from 2,000 to 20,000 and a glass transition temperature of from 30 to 90&#xb0; C. obtained by polymerizing a starting monomer containing from 15 to 50 mol % of an unsaturated compound which contains at least a glycidyl group and/or a methylglycidyl group, and from 20 to 50 mol % of methyl methacrylate; a curing agent (B) capable of being reacted with the glycidyl group or the methylglycidyl group constituting the curable acrylic resin (A); and an alcohol solvent (C) having a boiling point under normal pressure of from 70 to 120&#xb0; C.; said method comprising a kneading step of so kneading the curable acrylic resin (A), the curing agent (B) and the alcohol solvent (C) that at least the curing agent (B) is dissolved in the alcohol solvent (C) at a temperature of not higher than 130&#xb0;C., and a vapor-removing step of continuously vapor-removing the alcohol solvent (C) under a reduced pressure at a temperature of not higher than 130&#xb0; C.

Method of producing powdery coating material

The process of the present invention for producing a polyester resin comprising a dicarboxylic acid constitutional unit and a diol constitutional unit having a cyclic acetal skeleton comprises a step (1) of subjecting a diol (A) having a cyclic acetal skeleton and an ester (D) to transesterification reaction and a step (2) of mainly converting the resultant oligomer into a high polymer. The step (1) simultaneously satisfies the requirements (i) to (iv) as described in the specification. In the process of the present invention, the polyester resins having excellent moldability and mechanical properties are stably produced by a transesterification method which is less detrimental to environments.

Method of producing polyester powdery coating

In the production method of the present invention, a copolyester of intended sublimable diol proportion is produced by the reaction of a dicarboxylic acid and/or an ester-forming derivative thereof with a sublimable diol and a non-sublimable diol with an increased conversion of the sublimable diol. Since the escape of the sublimable diol is effectively prevented, the process solves the problem of clogging pressure-reduced pipes, etc. of an apparatus for polyester resin production.

Process for producing copolyester resin

A high quality copolymer of styrene and methyl methacrylate is economically produced by polymerizing styrene and methyl methacrylate in a homogeneous solution of raw materials comprising methyl methacrylate, styrene, and an antioxidant, while the solution of raw materials is continuously supplied to a polymerization reactor including at least one complete-mixing type reaction tank, continuously removing the polymerization product from the polymerization reactor, supplying the polymerization product removed from the polymerization reactor directly to an extruder having a plurality of vents, and extruding a copolymer from the extruder, while volatile matter are removed through the plurality of vents.

Process for producing a copolymer

A process is provided for preparing a high-quality methyl methacrylate polymer by polymerizing a monomer comprising methyl methacrylate as a main component in the presence of a radical polymerization initiator, a chain transfer agent, and 5 to less than 10 wt. % methanol. The polymerization is carried out in a uniform solution. According to this process, a methyl methacrylate polymer is obtained which reduces the generation of silver streaks, voids, coloring, odor and the like at the time of thermal molding.

Process for preparing methyl methacrylate polymer

A process for purifying a polymer by separating and removing volatile components from a polymer composition containing the volatile components, which comprises: (a) heating the polymer composition containing a methanol solvent to a temperature of 120.degree. to 240.degree. C. by a heater, wherein an internal pressure the heater is maintained at 8 to 35 kg/cm.sup.2 G; (b) discharging the heated polymer composition into a tank in which pressure is maintained at -0.7 to 1.0 kg/cm.sup.2 G, and then separating and collecting most of the volatile components to lower the concentration of the solvent in the remaining volatile components in the polymer composition to 0.5% by weight or less; and (c) feeding the resultant polymer composition to a vent extruder maintained such that a barrel temperature at an inner side thereof is 160.degree. to 280.degree. C. and pressure in a vent portion is 5 to 400 Torr, and then extruding the polymer composition to lower the content of the remaining volatile components in the composition to 1% by weight or less. Alternatively, between the above-mentioned steps (b) and (c), there can be interposed a step (b') of introducing an inert gas into the polymer composition before heating or during heating, or in the vicinity of the polymer composition which is being discharged into the tank. By using this process, a polymer can easily be separated and purified, so that a high-quality polymer, particularly a methyl methacrylate polymer, can be efficiently manufactured, without polymer discoloration.

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Kanagawa, Japan

Shojiro Kuwahara