Method for producing (meth)acrylic resin composition

Patent metadata

Field	Value
Publication number	US-2017226237-A1
Application number	US-201515501586-A
Country	US
Kind code	A1
Filing date	Aug 6, 2015
Priority date	Aug 6, 2014
Publication date	Aug 10, 2017
Grant date	—

Abstract

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.

First claim

1 . A method for producing a (meth)acrylic resin composition, the method comprising:
continuously feeding a raw material solution into a tank reactor, wherein the raw material solution comprises methyl methacrylate, a chain transfer agent and a radical polymerization initiator, and optionally comprises 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; bulk-polymerizing in the tank reactor at a polymerization conversion ratio of 40 to 70% by mass to obtain a reaction product; 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.

2 . The method according to claim 1 , further comprising:
purging an additive preparation tank with an inert gas; and subsequently melting at least one additive in the additive preparation tank to obtain the liquid additive.

3 . The method according to claim 1 , further comprising:
storing the liquid additive at not more than 130° C.

4 . The method according to claim 1 , wherein both of the removing the volatile matter from the reaction product and the adding the filtrated liquid additive to the reaction product are conducted in a vented extruder.

5 . The method according to claim 4 , wherein the adding the filtrated liquid additive to the reaction product within the vented extruder is conducted at a position closer to a polymer outlet than a front vent closest to the polymer outlet.

6 . The method according to claim 1 , wherein the raw material solution is prepared by mixing a raw material solution (A) comprising the methyl methacrylate and the chain transfer agent and optionally comprising the acrylic acid alkyl ester with a raw material solution (B) comprising the radical polymerization initiator and methyl methacrylate.

7 . The method according to claim 1 , wherein the continuously feeding a raw material solution, the bulk-polymerizing, the continuously discharging the reaction product, the heating the discharged reaction product, the removing volatile matter, the filtrating a liquid additive and the adding the filtrated liquid additive are carried out concurrently.

8 . The method according to claim 1 , wherein the chain transfer agent is a monofunctional alkylmercaptan.

9 . The method according to claim 1 , wherein the radical polymerization initiator has a half-life of 0.5 to 120 seconds at a temperature inside the tank reactor.

10 . The method according to claim 1 , wherein the polymerization initiator has a hydrogen abstraction capacity of not more than 40%.

11 . The method according to claim 1 , wherein the polymerization initiator is 2,2′-azobis(2-methylpropionitrile), t-hexylperoxy 2-ethylhexanoate, 1,1-bis(t-hexylperoxy)cyclohexane, or dimethyl 2,2′-azobis(2-methylpropionate).

12 . The method according to claim 6 , wherein the raw material solution (A) comprises 0.1 ppm to 50 ppm of a polymerization inhibitor.

13 . The method according to claim 6 , wherein the raw material solution (A) has a dissolved oxygen concentration of not more than 50 ppm.

14 . The method according to claim 6 , wherein the raw material solution (A) has a b* value of −1 to +2.

15 . The method according to claim 6 , wherein the raw material solution (A) is obtained by mixing methyl methacrylate, the acrylic acid alkyl ester and the chain transfer agent at a predetermined proportion and then bringing the resulting mixture into contact with an inert gas for removal of dissolved oxygen.

16 . The method according to claim 15 , wherein a ratio of the amount of the raw material solution (A) being fed (kg/h) to the amount of the inert gas being fed (Nm 3 /h) is less than 0.30.

17 . The method according to claim 6 , wherein the concentration of the radical polymerization initiator in the raw material solution (B) is not less than 0.01% by mass and less than 4% by mass.

18 . The method according to claim 6 , wherein the raw material solution (B) comprises 0.1 ppm to 50 ppm of a polymerization inhibitor.

19 . The method according to claim 6 , wherein the temperature of the raw material solution (B) in the presence of oxygen is maintained at not more than 0° C.

20 . The method according to claim 4 , wherein the vented extruder is equipped with a breaker plate or a screen at a polymer outlet.

21 . The method according to claim 1 , wherein the filter has an operating temperature limit of not less than 140° C.

22 . The method according to claim 1 , wherein a reaction tank in the tank reactor is equipped with a Maxblend stirring device.

23 . The method according to claim 1 , wherein a polymerization conversion ratio of the bulk polymerization reaches 40 to 70% by mass.

24 . The method according to claim 1 , wherein a temperature of a liquid in a reactor tank in the tank reactor is 100° C. to 170° C.

25 . The method according to claim 1 , wherein an amount of a liquid in a reaction tank in the tank reactor is not less than ¼ the capacity of the reaction tank.

26 . The method according to claim 1 , wherein a water content of a liquid in the tank reactor is not more than 1000 ppm.

Assignees

• Kuraray Co

Inventors

• Kitade Yasuhito
• Ozawa Hiroshi
• Tanaka Shouji

Classifications

• C08K5/09

  Carboxylic acids; Metal salts thereof; Anhydrides thereof · CPC title

• C08F2/38

  Polymerisation using regulators, e.g. chain terminating agents {, e.g. telomerisation} · CPC title

• C08K5/101

  of monocarboxylic acids · CPC title

• C08F6/005

  from solid polymers · CPC title

• C08F20/14 Primary

  Methyl esters {, e.g. methyl (meth)acrylate} · CPC title