US 7,018,697 B2 · Optical recording medium

Abstract

An optical recording medium including a substrate and a light transmitting layer provided on the substrate so as to have a smaller thickness than that of the substrate, which is hardly warped and excellent in electrical characteristics and productivity, is provided. An optical recording medium includes: a substrate; and a light transmitting layer having a smaller thickness than that of the substrate. In this medium, a material of the substrate is an olefin maleimide copolymer.

Drawings

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Drawings

Claims1

Dependent claims

An optical recording medium comprising:

a substrate;
and
a light transmitting layer having a thickness smaller than that of the substrate, wherein a material of the substrate is an olefin maleimide copolymer,
the olefin maleimide copolymer is a copolymer comprising:
at least one kind of an N-phenyl-substituted maleimide unit represented by the general formula (I),
at least one kind of an N-alkyl maleimide unit represented by the general formula (II), and
an α-olefin unit represented by the general formula (III), and
wherein a copolymer composition is such that a total content of (I) and (II) is in a range of 30 to 98 mol % and a content of (III) is in a range of 70 to 2 mol %, and a weight-average molecular weight relative to polystyrene is in a range of 1×103 to 5×106
where R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are independently hydrogen, halogen, a carboxylic acid, or a straight-chain or branched alkyl group having 1 to 8 carbon atoms, and R11, R12, and R13 are independently hydrogen or an alkyl group having 1 to 6 carbons.

6 more elements

Dependencies are inferred from the claim text.

Description3,862 words

Summary1,385 words

#1. Field of the Invention

#The present invention relates to an optical recording medium including a substrate and a light transmitting layer having a smaller thickness than that of the substrate.

#2. Description of the Related Art

Brief description of the drawings2 figures

#FIG. 1 is a sectional side view schematically showing a structure of an optical recording medium according to an embodiment of the present invention; and

#FIG. 2 is a graph showing changes in warp angle of optical recording media according to the embodiment of the present invention and a Comparative Example in comparison.

Detailed description2,424 words

#Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

#FIG. 1 is a sectional side view schematically showing a structure of an optical recording medium 10 according of the present invention.

#The optical recording medium 10 includes: a substrate 12; and a light transmitting layer 14 having a smaller thickness than that of the substrate 12, and is characterized in that a material of the substrate 12 is an olefin maleimide copolymer having a high rigidity. Since the remaining structure is similar to that of a conventional optical recording medium, the description thereof is herein appropriately omitted.

Facts

Application

10/854,713Filed 27 May 2004

Priority

JP 2003-15296029 May 2003

Published

US 2004/0241378 A12 Dec 2004

Granted

28 Mar 2006

Term ended

27 May 2024

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification5 codes

G11B 7/2533
Of substrates: comprising resins
G11B 7/252
Characterised by the selection of the material: of layers other than recording layers
Y10T 428/21
Stock material or miscellaneous articles: circular sheet or circular blank
G11B
Information storage based on relative movement between record carrier and transducer

Optical recording medium

Life of this patent

Optical recording medium

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims1

Description3,862 words

Drawings

Classification5 codes

Life of this patent

Description3,862 words