Kuraray Co., Ltd.

Shouji Tanaka

Hiroshi Ozawa

Yasuhito Kitade

A method for producing a (meth)acrylic resin composition, comprising: continuously feeding reaction starting materials to a tank reactor, the reaction starting materials comprising a polymerizable monomer component, a chain transfer agent and a radical polymerization initiator, the polymerizable monomer component comprising 50 to 100% by mass of methyl methacrylate, 0 to 20% by mass of an acrylic acid alkyl ester and 0 to 30% by mass of an additional monomer; conducting bulk polymerization of the polymerizable monomer component at a polymerization conversion ratio of 40 to 70% by mass to obtain a liquid containing a (meth)acrylic resin; continuously feeding the resulting liquid to a vented extruder to separate volatile component from the (meth)acrylic resin; conducting distillation using an atmospheric distillation column to separate the volatile component into a high boiling fraction (C) and a low boiling fraction (A); and conducting distillation using a vacuum distillation column having a pressure of &#x2212;50 kPaG to &#x2212;101 kPaG at the top of the vacuum distillation column to separate the high boiling fraction (C) into a high boiling fraction (C) and a low boiling fraction (A); reusing the low boiling fraction (A) and the low boiling fraction (A) as part of the reaction starting materials.

Process for producing (meth)acrylic resin composition

A (meth)acrylic resin composition is obtained by a method comprising: continuously feeding a raw material solution essentially comprising methyl methacrylate, a chain transfer agent and a radical polymerization initiator, and optionally comprising an acrylic acid alkyl ester in a mass ratio of the acrylic acid alkyl ester to the methyl methacrylate of 0/100 to 20/80 into a tank reactor to allow bulk polymerization to proceed in the tank reactor at a polymerization conversion ratio of 40 to 70% by mass to obtain a reaction product while continuously discharging the reaction product from the tank reactor; heating the discharged reaction product with a heat exchanger; removing volatile matter from the heated reaction product; filtrating a liquid additive through a filter; and adding the filtrated liquid additive to the reaction product from which the volatile matter has been removed.

Method for producing (meth)acrylic resin composition

A method for producing a (meth)acrylic resin composition, the method comprising continuously feeding a polymerizable monomer component comprising 50 to 100% by mass of methyl methacrylate, 0 to 20% by mass of an acrylic acid alkyl ester and 0 to 30% by mass of an additional monomer, a chain transfer agent, and a radical polymerization initiator to a tank reactor; conducting bulk polymerization of the polymerizable monomer component at a polymerization conversion ratio of 40 to 70% by mass to obtain a liquid containing a (meth)acrylic resin; continuously feeding the liquid to a vented extruder to separate a volatile component from the (meth)acrylic resin; continuously feeding the separated volatile component to a distillation column to obtain a fraction containing methyl methacrylate; adding a polymerization inhibitor to the fraction; and reusing the fraction which contains the polymerization inhibitor as part of the polymerizable monomer component.

A (meth)acrylic resin composition is obtained by a method that comprises: preparing a liquid starting material (A) comprising methyl methacrylate, an acrylic acid alkyl ester and a chain transfer agent, having a mass ratio of the acrylic acid alkyl ester to the methyl methacrylate of 0/100 to 20/80, and having a dissolved oxygen concentration of not more than 50 ppm, preparing a liquid starting material (B) comprising a radical polymerization initiator, a polymerization inhibitor and methyl methacrylate, and having been maintained at a temperature of not more than 10&#xb0; C. in the presence of oxygen, continuously feeding the liquid starting material (A) and the liquid starting material (B) into a tank reactor, allowing bulk polymerization to proceed in the tank reactor at a polymerization conversion ratio of 40 to 70% by mass to give a reaction product, and continuously discharging the reaction product from the tank reactor.

Production method of (meth)acrylic resin composition

A method of producing a (meth)acrylic resin composition. The method comprises a step of continuously feeding a monomer mixture comprising 80 to 100% by mass of methyl methacrylate and 20 to 0% by mass of an alkyl acrylate to a tank reactor and bulk polymerizing the monomer mixture until obtaining a polymerization conversion of 40 to 70% by mass to prepare a reaction product; continuously discharging the reaction product, and heating the reaction product to 200&#xb0; C. to 270&#xb0; C. with a heater, and then separating the unreacted monomer with a extruder equipped with a vent; and transferring the separated unreacted monomer entrained by an inert gas flow to reuse the separated unreacted monomer as a raw material of the monomer mixture.

A method for producing a (meth)acrylic resin composition, the method comprises the steps of continuously feeding methyl methacrylate and the other materials into a tank reactor while controlling each of the amounts thereof, performing bulk polymerization in the tank reactor to obtain a reaction product, recovering a mixture (A) containing methyl methacrylate and the others from the reaction product, and continuously feeding the mixture (A) into the tank reactor, wherein each of the amounts of methyl methacrylate and the others being fed into the tank reactor are controlled on the basis of the amount of the mixture (A) being fed into the tank reactor and the proportions of methyl methacrylate and the others in the mixture (A), and the perfect-mixing time of the tank reactor, the half life of a radical polymerization initiator at a temperature equal to the temperature inside the tank reactor, the agitation power of the tank reactor, the mean residence time of a reaction starting material in the tank reactor, and the concentration of the radical polymerization initiator in the reaction starting material satisfy a particular relationship.

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Tainai, Japan

Shouji Tanaka