Methacrylic resin composition, resin modifier, and molded article

Patent metadata

Field	Value
Publication number	US-9527994-B2
Application number	US-201113881310-A
Country	US
Kind code	B2
Filing date	Oct 24, 2011
Priority date	Oct 29, 2010
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

An object of the present invention is to provide a methacrylic resin composition which exhibits excellent flexibility, elasticity, impact resistance, and plasticity and moldability while transparency inherent to methacrylic resins is maintained. A methacrylic resin composition to be produced is composed of 10 to 99 parts by mass of a methacrylic resin (A) containing not less than 80 mass % of a methyl methacrylate unit and 90 to 1 part by mass of a block copolymer (B) containing 10 to 60 mass % of a methyl methacrylate polymer block (b1) and 90 to 40 mass % of an acrylate polymer block (b2) and having a refractive index of 1.485 to 1.495 (the total of (A) and (B) is 100 parts by mass).

First claim

The invention claimed is:

1. A resin modifier, comprising:
a block copolymer (B) comprising from 10 to 60 mass % of a methyl methacrylate polymer block (a) and from 90 to 40 mass % of an acrylate polymer block (b),
wherein the acrylate polymer block (b) comprises from 50 to 90 mass % of an alkyl acrylate and from 50 to 10 mass % of an aromatic (meth)acrylate, and the alkyl acrylate is at least one selected from the group consisting of n-butyl acrylate and 2-ethylhexyl acrylate, and
wherein the block copolymer (B) has a refractive index of from 1.485 to 1.495,
wherein the methyl methacrylate polymer block (a) has a refractive index ranging from 1.485 to 1.495 and the acry late polymer block (b) has a refractive index ranging from 1.485 to 1.495.

2. The resin modifier according to claim 1 , wherein the aromatic (meth)acrylate is benzyl acrylate.

3. A methacrylic resin composition, comprising:
from 10 to 99 parts by mass of a methacrylic resin (A) comprising not less than 80 mass % of a methyl methacrylate unit and
from 90 to 1 part by mass of a block copolymer (B) comprising from 10 to 60 mass % of a methyl methacrylate polymer block (b1) and from 90 to 40 mass % of an acrylate polymer block (b2),
wherein the acrylate polymer block (b2) is a copolymer block comprising from 50 to 90 mass % of an alkyl acrylate and from 50 to 10 mass % of an aromatic (meth)acrylate, and the alkyl acrylate is at least one selected from the group consisting of n-butyl acrylate and 2-ethylhexyl acrylate, and
wherein the block copolymer (B) has a refractive index of from 1.485 to 1.495 and a total of (A) and (B) is 100 parts by mass,
wherein the methyl methacrylate polymer block (b1) has a refractive index ranging from 1.485 to 1.495 and the acrylate polymer block (b2) has a refractive index ranging from 1.485 to 1.495.

4. The methacrylic resin composition according to claim 3 , wherein the aromatic (meth)acrylate is benzyl acrylate.

5. The methacrylic resin composition according to claim 3 , wherein the methacrylic resin composition is suitable for producing a 3-mm-thick molded article having a haze of not more than 2%.

6. The methacrylic resin composition according to claim 5 , wherein the methacrylic resin composition comprises the acrylate polymer block (b2) in an amount of from 5 to 20 mass % and the methacrylic resin composition exhibits an MFR of not less than 20 g/10 min at 230° C. under 37.3 N.

7. A molded article, comprising:
the methacrylic resin composition according to claim 3 .

8. The molded article according to claim 7 , wherein the molded article is an injection-molded article.

9. The methacrylic resin composition according to claim 3 , wherein the block copolymer (B) is a diblock copolymer.

10. The methacrylic resin composition according to claim 3 , wherein the block copolymer (B) is a triblock copolymer.

Assignees

• Ozawa Hiroshi
• Takahashi Toru
• Matsumura Atsushi
• Hamada Kenichi
• Morishita Yoshihiro
• Kurihara Toyoaki
• Kuraray Co

Inventors

• Ozawa Hiroshi
• Takahashi Toru
• Matsumura Atsushi
• Hamada Kenichi
• Morishita Yoshihiro
• Kurihara Toyoaki

Classifications

• C08F297/026

  polymerising acrylic acid, methacrylic acid or derivatives thereof · CPC title

• C08L53/00 Primary

  Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers · CPC title

• C08F220/1807

  C7-(meth)acrylate, e.g. heptyl (meth)acrylate or benzyl (meth)acrylate · CPC title

• B29K2233/12

  Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate · CPC title

• C08L33/08

  Homopolymers or copolymers of acrylic acid esters · CPC title