Methacrylic resin

Patent metadata

Field	Value
Publication number	US-10174145-B1
Application number	US-201815880480-A
Country	US
Kind code	B1
Filing date	Jan 25, 2018
Priority date	Jan 25, 2018
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

Methacrylic resin having high heat resistance, highly controlled birefringence, excellent color tone and transparency, and excellent moldability is provided. A methacrylic resin comprises a structural unit (B) having a cyclic structure-containing main chain, the structural unit (B) including at least one structural unit selected from the group consisting of an N-substituted maleimide-based structural unit (B-1) and a lactone ring structural unit (B-2), wherein a glass transition temperature is more than 120° C. and 160° C. or less, an amount of a methanol-soluble content is 5 mass % or less relative to 100 mass % of a total amount of the methanol-soluble content and a methanol-insoluble content in the methacrylic resin, and an yellowness index YI measured using a 10 cm optical path length cell for a 20 w/v % chloroform solution of the methanol-insoluble content is 0 to 7.

First claim

The invention claimed is:

1. A methacrylic resin composition consisting essentially of a methacrylic resin, the methacrylic resin comprising
a structural unit (B) having a cyclic structure-containing main chain, the structural unit (B) including at least one structural unit selected from the group consisting of an N-substituted maleimide-based structural unit (B-1) and a lactone ring structural unit (B-2), wherein
a glass transition temperature of the methacrylic resin is more than 120° C. and 160° C. or less,
an amount of a methanol-soluble content is 5 mass % or less relative to 100 mass % of a total amount of the methanol-soluble content and a methanol-insoluble content in the methacrylic resin, and
an yellowness index YI measured using a 10 cm optical path length cell for a 20 w/v % chloroform solution of the methanol-insoluble content of the methacrylic resin is 0 to 7.

2. The methacrylic resin composition according to claim 1 , wherein
a transmittance in 680 nm as measured using the 10 cm optical path length cell for the 20 w/v % chloroform solution of the methanol-insoluble content is 90% or more.

3. The methacrylic resin composition according to claim 1 , wherein the methacrylic resin comprises 50 mass % to 97 mass % of a methacrylic acid ester monomer unit (A), relative to 100 mass % of the methacrylic resin.

4. The methacrylic resin composition according to claim 1 , wherein
the methacrylic resin comprises 3 mass % to 30 mass % of the structural unit (B) having a cyclic structure-containing main chain, and 0 mass % to 20 mass % of an other vinyl-based monomer unit (C) copolymerizable with a methacrylic acid ester monomer, relative to 100 mass % of the methacrylic resin.

5. The methacrylic resin composition according to claim 4 , wherein
the structural unit (B) is contained in an amount of 45 mass % to 100 mass % relative to 100 mass %, in total, of the structural unit (B) and the monomer unit (C).

6. The methacrylic resin composition according to claim 4 , wherein
the monomer unit (C) includes at least one structural unit selected from the group consisting of an acrylic acid ester monomer, an aromatic vinyl-based monomer, and a vinyl cyanide-based monomer.

7. The methacrylic resin composition according to claim 1 , wherein the methacrylic resin has a photoelastic coefficient of −2×10 −12 Pa −1 to +2×10 −12 Pa −1 .

8. The methacrylic resin composition according to claim 1 , wherein the methacrylic resin has a ratio Mz/Mw of a Z-average molecular weight Mz to a weight-average molecular weight Mw of 1.3 to 2.0 as measured by gel permeation chromatography (GPC).

9. The methacrylic resin composition according to claim 2 , wherein the methacrylic resin comprises 50 mass % to 97 mass % of a methacrylic acid ester monomer unit (A), relative to 100 mass % of the methacrylic resin.

10. The methacrylic resin composition according to claim 2 , wherein the methacrylic resin has a photoelastic coefficient of −2×10 −12 Pa −1 to +2×10 −12 Pa −1 .

11. The methacrylic resin composition according to claim 2 , wherein the methacrylic resin has a ratio Mz/Mw of a Z-average molecular weight Mz to a weight-average molecular weight Mw of 1.3 to 2.0 as measured by gel permeation chromatography (GPC).

12. The methacrylic resin composition according to claim 3 , wherein the methacrylic resin has a photoelastic coefficient of −2×10 −12 Pa −1 to +2×10 −12 Pa −1 .

13. The methacrylic resin composition according to claim 3 , wherein the methacrylic resin has a ratio Mz/Mw of a Z-average molecular weight Mz to a weight-average molecular weight Mw of 1.3 to 2.0 as measured by gel permeation chromatography (GPC).

14. The methacrylic resin composition according to claim 7 , wherein the methacrylic resin has a ratio Mz/Mw of a Z-average molecular weight Mz to a weight-average molecular weight Mw of 1.3 to 2.0 as measured by gel permeation chromatography (GPC).

15. The methacrylic resin composition according to claim 10 , wherein the methacrylic resin has a ratio Mz/Mw of a Z-average molecular weight Mz to a weight-average molecular weight Mw of 1.3 to 2.0 as measured by gel permeation chromatography (GPC).

16. The methacrylic resin composition according to claim 9 , wherein the methacrylic resin has a photoelastic coefficient of −2×10 −12 Pa −1 to +2×10 −12 Pa −1 .

17. The methacrylic resin composition according to claim 16 , wherein the methacrylic resin has a ratio Mz/Mw of a Z-average molecular weight Mz to a weight-average molecular weight Mw of 1.3 to 2.0 as measured by gel permeation chromatography (GPC).

Assignees

• Asahi Chemical Ind

Inventors

• Yoshida Junichi
• Watanabe Harumi
• Iwase Katsuhiro
• Sasaki Keigo
• Kazunori Miyuki

Classifications

• C08F212/08

  Styrene · CPC title

• C08L33/10

  Homopolymers or copolymers of methacrylic acid esters · CPC title

• C08F222/40

  Imides, e.g. cyclic imides · CPC title

• C08F220/281

  and containing only one oxygen, e.g. furfuryl (meth)acrylate or 2-methoxyethyl (meth)acrylate · CPC title

• C08L33/12

  Homopolymers or copolymers of methyl methacrylate · CPC title