US5053288A — Optical recording medium

Claim 1

Independent Claim 170 words

An optical recording medium, comprising: a hard plastic substrate; an optical recording film formed over said hard plastic substrate; and a UV-cured resin layer formed over said optical recording film, said UV-cured resin being formed by curing a UV-curable resin composition which comprises: a) 15 to 85% by weight of a first ingredient of an acrylate and/or a methacrylate having at least three functionalities; b) 15 to 70% by weight of a second ingredient of a compound having a linear structure and a molecular weight of at least 300 and a molecular weight of at least 150 per ethlenically unsaturated bond; c) at least 0.3% by weight of a photopolymerization initiator; and d) not more than 40% by weight of a third ingredient of an acrylate and/or methacrylate having two functionalities; said UV-curable resin composition containing as an ingredient substantially no acrylate or methacrylate having one functionality, wherein said UV-cured resin layer has an acid value of not more than 1.5 and a softening point not lower than 50° C.

Claim 2

Dependent Claim 170 words

An optical recording medium, comprising: a hard plastic substrate; an optical recording film formed over said hard plastic substrate; and a UV-cured resin layer formed over said optical recording film, said UV-cured resin being formed by curing a UV-curable resin composition which comprises: a) 15 to 85% by weight of a first ingredient of an acrylate and/or a methacrylate having at least three functionalities; b) 15 to 70% by weight of a second ingredient of a compound having a linear structure and a molecular weight of at least 300 and a molecular weight of at least 150 per ethlenically unsaturated bond; c) at least 0.3% by weight of a photopolymerization initiator; and d) not more than 40% by weight of a third ingredient of an acrylate and/or methacrylate having two functionalities; said UV-curable resin composition containing as an ingredient substantially no acrylate or methacrylate having one functionality, wherein said UV-cured resin layer has an acid value of not more than 1.5 and a softening point not lower than 50° C.

Claim 3

Dependent Claim 36 words

An optical recording medium according to claim 1, wherein said optical recording film is a magneto-optical recording film of an amorphous film consisting of at least one rare earth metal and at least one transition metal.

Claim 4

Dependent Claim 30 words

An optical medium according to claim 1, wherein said UV-cured resin layer has an acid value of not more than 0.1 and a softening point not lower than 115° C.

Claim 5

Dependent Claim 35 words

An optical medium according to claim 1, wherein said second ingredient is an addition polymerizable compound having at least one ethylenically unsaturated bond and a molecular weight of at least 150 per ethylenically unsaturated bond.

Claim 6

Dependent Claim 20 words

An optical medium according to claim 4, wherein said second ingredient is a phenol-based novolak epoxy acrylate or methacrylate compound.

Claim 7

Dependent Claim 41 words

An optical medium according to claim 1, wherein said UV-curable resin composition comprises 25 to 75% by weight of said first ingredient, 25 to 55% by weight of said second ingredient and at least 0.3% by weight of said photopolymerization initiator.

Claim 8

Dependent Claim 23 words

An optical medium according to claim 1, wherein said second ingredient has a molecular weight of more than 1000 per ethylenically unsaturated bond.

Claim 9

Dependent Claim 19 words

An optical medium according to claim 1, further comprising an inorganic layer between said recording film and said substrate.

Claim 10

Dependent Claim 24 words

An optical recording medium according to claim 1, further comprising another hard plastic substrate laminated over said UV-cured resin layer by an adhesive layer.

Claim 11

Dependent Claim 25 words

An optical medium according to claim 9, further comprising another optical recording layer formed between said UV-cured resin layer and said another hard plastic substrate.

Claim 12

Dependent Claim 188 words

A process for manufacturing an optical recording medium, said process comprising the steps of: forming an optical recording film over a hard plastic substrate; coating a UV-curable resin composition over said optical recording film to form a UV-curable resin layer, said UV-curable resin composition comprising; a) 15 to 85% by weight of a first ingredient of an acrylate and/or a methacrylate having at least three functionalities; b) 15 to 70% by weight of a second ingredient of a compound having a linear structure and a molecular weight of at least 300 and a molecular weight of at least 150 per ethlenically unsaturated bond; c) at least 0.3% by weight of a photopolymerization initiator; and d) not more than 40% by weight of a third ingredient of an acrylate and/or methacrylate having two functionalities; said UV-curable resin composition containing as an ingredient substantially no acrylate or methacrylate having one functionality, said UV-curable resin composition having an acid value of not more than 1.5 and a viscosity of 10 to 5,000 cps at 25° C.; and irradiating said UV-curable resin layer with UV rays to form said UV-cured resin layer.

Claim 13

Dependent Claim 188 words

A process for manufacturing an optical recording medium, said process comprising the steps of: forming an optical recording film over a hard plastic substrate; coating a UV-curable resin composition over said optical recording film to form a UV-curable resin layer, said UV-curable resin composition comprising; a) 15 to 85% by weight of a first ingredient of an acrylate and/or a methacrylate having at least three functionalities; b) 15 to 70% by weight of a second ingredient of a compound having a linear structure and a molecular weight of at least 300 and a molecular weight of at least 150 per ethlenically unsaturated bond; c) at least 0.3% by weight of a photopolymerization initiator; and d) not more than 40% by weight of a third ingredient of an acrylate and/or methacrylate having two functionalities; said UV-curable resin composition containing as an ingredient substantially no acrylate or methacrylate having one functionality, said UV-curable resin composition having an acid value of not more than 1.5 and a viscosity of 10 to 5,000 cps at 25° C.; and irradiating said UV-curable resin layer with UV rays to form said UV-cured resin layer.

Claim 14

Dependent Claim 30 words

An optical process according to claim 11, wherein said UV-cured resin layer has an acid value of not more than 0.1 and a softening point not lower than 115° C.

Claim 15

Dependent Claim 35 words

A process according to claim 11, further comprising the step of placing another hard plastic substrate over said UV-curable resin layer between said steps of forming the UV-curable resin layer and the UV irradiation thereof.

Claim 16

Dependent Claim 40 words

A process according to claim 13, wherein said another hard plastic substrate includes another optical recording film on a side thereof and said another optical recording film is located between said another hard plastic substrate and said UV-cured resin layer.

Claim 17

Dependent Claim 22 words

An optical recording medium according to claim 1, wherein said UV-cured resin layer has an acid value of not more than 0.7.

Claim 18

Dependent Claim 22 words

An optical recording medium according to claim 15, wherein said UV-cured resin layer has an acid value of not more than 0.1.

Claim 19

Dependent Claim 22 words

An optical recording medium according to claim 1, wherein said UV-cured resin layer has a softening point not lower than 80° C.

Claim 20

Dependent Claim 22 words

An optical recording medium according to claim 17, wherein said UV-cured resin layer has a softening point not lower than 115° C.

Claim 21

Dependent Claim 31 words

An optical recording medium according to claim 1, wherein said UV-cured resin layer has an acid value of not more than 0.7 and a softening point not lower than 80° C.

Claim 22

Dependent Claim 33 words

An optical recording medium according to claim 9, wherein said UV-cured resin layer itself is adhesive and wherein said optical recording medium comprises another hand plastic substrate adherence to said UV-cured resin layer.

Claim 23

Dependent Claim 20 words

A process according to claim 11, wherein said UV-curable resin composition has an acid value of not more than 0.7.

Claim 24

Dependent Claim 20 words

A process according to claim 21, wherein said UV-curable resin composition has an acid value of not more than 0.1.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-09-30	1995-04-01	1995-10-01	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-09-30	1999-04-01	1999-10-01	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-09-30	2003-04-01	2003-10-01	$7700.00	Window Closed / Lapsed

Optical recording medium

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