Method for manufacturing methacrylic resin composition

Patent metadata

Field	Value
Publication number	US-11286237-B2
Application number	US-202016920753-A
Country	US
Kind code	B2
Filing date	Jul 6, 2020
Priority date	Aug 30, 2016
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

Provided is a method for manufacturing a methacrylic resin composition having excellent surface processability and displaying excellent preservability of formed surface processing. A method for manufacturing a methacrylic resin composition, wherein the methacrylic resin composition comprises two or more types of methacrylic resins that each have a structural unit (X) having the same type of cyclic structure-containing main chain, the methacrylic resin composition has a Vicat softening temperature of 120° C. to 160° C., methanol-soluble content is contained in an amount of 5 mass % or less relative to 100 mass %, in total, of the methanol-soluble content and methanol-insoluble content, comprising mixing a low molecular weight component and a high molecular weight component.

First claim

The invention claimed is:

1. A method for manufacturing a methacrylic resin composition, the method comprising:
mixing a low molecular weight methacrylic resin having a weight average molecular weight (Mw) of 70,000 to 157,000 and a ratio (S/H) of integrated intensity (S) of a syndiotactic fraction (rr) relative to integrated intensity (H) of a heterotactic fraction (mr), as determined by 1 H-NMR measurement, is 1.10 to 1.40, and a high molecular weight methacrylic resin having a weight average molecular weight (Mw) of 185,000 to 800,000 and a ratio (S/H) of integrated intensity (S) of a syndiotactic fraction (rr) relative to integrated intensity (H) of a heterotactic fraction (mr), as determined by 1 H-NMR measurement, is 1.30 to 1.95,
wherein
the low molecular weight methacrylic resin and the high molecular weight methacrylic resin each have a structural unit (X) having same cyclic structure-containing main chain and said cyclic structure-containing main chain includes a lactone ring structural unit,
the methacrylic resin composition comprises the low molecular weight methacrylic resin and the high molecular weight methacrylic resin,
the methacrylic resin composition has a Vicat softening temperature of 120° C. to 160° C.,
methanol-soluble content is contained in an amount of 5 mass % or less relative to 100 mass %, in total, of the methanol-soluble content and methanol-insoluble content,
and
a total content of the lactone ring structural units is 5 mass % to 40 mass % relative to 100 mass % of the methacrylic resin composition.

2. The method for manufacturing a methacrylic resin composition according to claim 1 , wherein the methacrylic resin composition has a weight average molecular weight (Mw) of 120,000 to 200,000 as measured by gel permeation chromatography as a polymethyl methacrylate equivalent molecular weight.

3. The method for manufacturing a methacrylic resin composition according to claim 1 , wherein the methacrylic resin composition has a photoelastic coefficient with an absolute value of 2.0×10 −12 Pa −1 or less.

4. The method for manufacturing a methacrylic resin composition according to claim 3 , wherein the methacrylic resin composition has a photoelastic coefficient with an absolute value of 1.0×10 −12 Pa −1 or less.

Assignees

• Asahi Chemical Ind

Inventors

• Iwase Katsuhiro
• Watanabe Harumi
• Sasaki Keigo

Classifications

• C07D207/448 Primary

  with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms, e.g. maleimide · CPC title

• C08L33/24

  Homopolymers or copolymers of amides or imides · CPC title

• C08F220/14

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

• C08L33/10

  Homopolymers or copolymers of methacrylic acid esters · CPC title

• C08L35/06

  Copolymers with vinyl aromatic monomers · CPC title