Patent EP0273092A2 successfully refreshed from Google Patents.
EP0273092A2
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EP
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A random copolymer containing hexagonal imide units,a process for producing the same,and an optical disc substrate made of the random copolymer
Assignee: Asahi Kasei Corp
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Filing: 1987-03-03
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Granted: —
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Expires: 2007-03-03
Abstract
Abstract A novel random copolymer comprising, in specific ratios, methyl methacrylate units, aromatic vinyl compound units, methacrylic acid units, hexagonal anhydride units and hexagonal imide units of the formula has been found to have excellent optical properties, mechanical strength, heat distortion resistance, heat decomposition resistance and oil resistance, and have low water absorption. The copolymer can advantageously be employed as a material for parts of light electric apparatus, engineering plastics, lenses, optical fiber cables, and is especially useful as a material for a substrate of optical discs.
Inventors
- 👤 Akihiro Wada
- 👤 Rin-Ichi Kakuta
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 22:47
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/48; C08F2800/00; C08F2800/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
284 words
A substrate for an optical disc which is made of a random copolymer, comprising: (A) 29 to 92 % by weight, based on the copolymer, of methyl methacrylate units, (B) 5 to 67 % by weight, based on the copolymer, of aromatic vinyl compound units of the formula (I) wherein X is selected from the group consisting of a hydrogen atom and a methyl group, and Y and Z are independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a chlorine atom, (C) 1 to 10 % by weight, based on the copolymer, of methacrylic acid units, (D) 0 to 48 % by weight, based on the copolymer, of hexagonal anhydride units of the formula (II) and (E) 2 to 50 % by weight, based on the copolymer, of hexagonal imide units of the formula (III) wherein R is selected from the group consisting of a hydrogen atom and R¹ in which R¹ is selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an aralkyl group having 7 to 22 carbon atoms and an aryl group having 6 to 12 carbon atoms, the sum of said units (A) and (B) and the sum of said units (D) and (E) being respectively in the ranges of 49 to 97 % by weight and 2 to 50 % by weight based on the copolymer, wherein the random copolymer has a reduced viscosity (ηsp/C) of 0.15 to 2 dl/g as measured at 25 °C with respect to 0.5 dl of a solution of 0.15 g of the random copolymer in chloroform.
Claim 2
Dependent Claim
284 words
A substrate for an optical disc which is made of a random copolymer, comprising: (A) 29 to 92 % by weight, based on the copolymer, of methyl methacrylate units, (B) 5 to 67 % by weight, based on the copolymer, of aromatic vinyl compound units of the formula (I) wherein X is selected from the group consisting of a hydrogen atom and a methyl group, and Y and Z are independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a chlorine atom, (C) 1 to 10 % by weight, based on the copolymer, of methacrylic acid units, (D) 0 to 48 % by weight, based on the copolymer, of hexagonal anhydride units of the formula (II) and (E) 2 to 50 % by weight, based on the copolymer, of hexagonal imide units of the formula (III) wherein R is selected from the group consisting of a hydrogen atom and R¹ in which R¹ is selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an aralkyl group having 7 to 22 carbon atoms and an aryl group having 6 to 12 carbon atoms, the sum of said units (A) and (B) and the sum of said units (D) and (E) being respectively in the ranges of 49 to 97 % by weight and 2 to 50 % by weight based on the copolymer, wherein the random copolymer has a reduced viscosity (ηsp/C) of 0.15 to 2 dl/g as measured at 25 °C with respect to 0.5 dl of a solution of 0.15 g of the random copolymer in chloroform.
Claim 3
Dependent Claim
30 words
The substrate according to claim 1, wherein the proportion of said methyl methacrylate units (A) is in the range of 50 to 80 % by weight based on the copolymer.
Claim 4
Dependent Claim
37 words
The substrate according to claim 1 or 2, wherein the proportion of said aromatic vinyl compound units (B) of the formula (I) is in the range of 5 to 56 % by weight based on the copolymer.
Claim 5
Dependent Claim
33 words
The substrate according to any one of claims 1 to 3, wherein said aromatic vinyl compound units (B) are units selected from the group of styrene units, α-methylstyrene units, and a combination thereof.
Claim 6
Dependent Claim
39 words
The substrate according to any one of claims 1 to 4, wherein the proportion of said hexagonal anhydride units (D) of the formula (II) is in the range of 0 to 20 % by weight based on the copolymer.
Claim 7
Dependent Claim
39 words
The substrate according to any one of claims 1 to 5, wherein the proportion of said hexagonal imide units (E) of the formula (III) is in the range of 4 to 40 % by weight based on the copolymer.
Claim 8
Dependent Claim
37 words
The substrate according to any one of claims 1 to 6, wherein R in the formula (III) representing said hexagonal imide units (E) is a hydrogen atom, a methyl group, a cyclohexyl group or a phenyl group.
Claim 9
Dependent Claim
39 words
The substrate according to any one of claims 1 to 7, wherein the sum of said units (D) and (E) is in the range of 10 to 22.5 % by weight based on the total weight of the copolymer.
Claim 10
Dependent Claim
25 words
The substrate according to any one of claims 1 to 8, wherein the reduced viscosity (ηsp/C) is in the range of 0.15 to 0.8 dl/g.
Claim 11
Dependent Claim
25 words
The substrate according to any one of claims 1 to 9, wherein the reduced viscosity (ηsp/C) is in the range of 0.2 to 0.8 dl/g.
References Cited (Backward Citations)
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