US4734477A
Expired / Lapsed
US
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Method for cast molding plastic substrate
Assignee: Mitsubishi Chemical Corp
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Filing: 1986-07-16
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Granted: 1988-03-29
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Expires: 2006-07-16
Abstract
Abstract A method for producing a plastic substrate having Tg of 110 DEG C. or more is disclosed, which comprises radical polymerizing a polyfunctional (meth)acrylate compound in a mold by a cast molding method, removing the resulting substrate from the mold when the glass transition temperature of the substrate reaches 10 DEG to 100 DEG C., and then post-curing the substrate. The method of the present invention can provide high quality plastic substrates with high productivity.
Inventors
- 👤 Takao Inoue
- 👤 Tadashi Sakairi
- 👤 Mitsutoshi Aritomi
- 👤 Tadao Takeyama
- 👤 Takahiro Matsuo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:09
CPC Classifications
B; B29; B29C; B29C35/00; B29C35/02; B29C35/0222; B29C39/00; B29C39/003; B29C39/006; B29C35/08; B29K; B29K2033/00; B29K2033/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
144 words
A method for obtaining a molded transparent plastic substrate by radical polymerizing a polymerizable monomeric liquid composed of at least one polyfunctional (meth)acrylate compound, the polymerization reactions consisting essentially of radical polymerization reactions, any catalyst present being a radical initiator, by a cast molding method, wherein in a first step the final shape of the plastic substrate is obtained by radical polymerizing the polyfunctional (meth)acrylate compound under cast molding conditions in a mold until the glass transition temperature of the polymerizing composition reaches 10° to 100° C., in a second step the shaped substrate as obtained in the first step is removed from the mold and in a third step the substrate is post-cured free of the restraints of a mold to obtain a substrate having a glass transition temperature of 110° C. or more and having the shape imparted by the first step.
Claim 2
Independent Claim
144 words
A method for obtaining a molded transparent plastic substrate by radical polymerizing a polymerizable monomeric liquid composed of at least one polyfunctional (meth)acrylate compound, the polymerization reactions consisting essentially of radical polymerization reactions, any catalyst present being a radical initiator, by a cast molding method, wherein in a first step the final shape of the plastic substrate is obtained by radical polymerizing the polyfunctional (meth)acrylate compound under cast molding conditions in a mold until the glass transition temperature of the polymerizing composition reaches 10° to 100° C., in a second step the shaped substrate as obtained in the first step is removed from the mold and in a third step the substrate is post-cured free of the restraints of a mold to obtain a substrate having a glass transition temperature of 110° C. or more and having the shape imparted by the first step.
Claim 3
Dependent Claim
51 words
The method as claimed in claim 1, wherein the polyfunctional (meth)acrylate compound is a compound represented by the formula (I): ##STR2## wherein R 1 is an alcohol residue having 2 to 50 carbon atoms, R 2 is H or CH 3 , and n is an integer of 2 to 6.
Claim 4
Independent Claim
181 words
A method for obtaining a molded transparent plastic substrate by radical polymerizing a polymerizable monomeric liquid composed of at least one polyfunctional (meth)acrylate compound alone or admixed with at most 10% of other radical polymerizable monomers, the polymerization reactions consisting essentially of radical polymerization reactions, any catalyst present being a radical initiator, by a cast molding method, wherein in a first step the final shape of the plastic substrate is obtained by radical polymerizing the polyfunctional (meth)acrylate compound under cast molding conditions in a mold until the glass transition temperature of the polymerizing composition reaches 10° to 100° , in a second step the shaped substrate as obtained in the first step is removed from the mold, and in a third step the substrate is post-cured at a temperature below 150° C. free of the restraints of a mold to obtain a substrate having a glass transition temperature of 110° C. or more, and this substrate is then further post-cured at a temperature of 150° C. or more, the shape of the final product being that imparted by the first step.
Claim 5
Independent Claim
181 words
A method for obtaining a molded transparent plastic substrate by radical polymerizing a polymerizable monomeric liquid composed of at least one polyfunctional (meth)acrylate compound alone or admixed with at most 10% of other radical polymerizable monomers, the polymerization reactions consisting essentially of radical polymerization reactions, any catalyst present being a radical initiator, by a cast molding method, wherein in a first step the final shape of the plastic substrate is obtained by radical polymerizing the polyfunctional (meth)acrylate compound under cast molding conditions in a mold until the glass transition temperature of the polymerizing composition reaches 10° to 100° , in a second step the shaped substrate as obtained in the first step is removed from the mold, and in a third step the substrate is post-cured at a temperature below 150° C. free of the restraints of a mold to obtain a substrate having a glass transition temperature of 110° C. or more, and this substrate is then further post-cured at a temperature of 150° C. or more, the shape of the final product being that imparted by the first step.
Claim 6
Dependent Claim
50 words
The method as claimed in claim 3, wherein the polyfunctional(meth)acrylate compound is a compound represented by the formula (I): ##STR3## wherein R 1 is an alcohol residue having 2 to 50 carbon atoms, R 2 is H or CH 3 , and n is an integer of 2 to 6.
Claim 7
Dependent Claim
22 words
The method as claimed in claim 3, wherein the radical polymerization in the mold is carried out by irradiation with ultraviolet rays.
Claim 8
Dependent Claim
22 words
The method according to claim 2 wherein the polyfunctional (meth)acrylate compound is admixed with at most 10% of other radical polymerizable monomers.
Claim 9
Dependent Claim
22 words
The method according to claim 4, wherein the polyfunctional (meth)acrylate compound is admixed with at most 10% of other radical polymerizable monomers.
Claim 10
Dependent Claim
21 words
The method as claimed in claim 2 wherein the monomeric liquid is composed of at least one polyfunctional (meth)acrylate compound alone.
Claim 11
Dependent Claim
36 words
The method as claimed in claim 5 wherein the monomeric liquid is composed of at least one polyfunctional (methy)acrylate compound alone and the transparent substrate is a disc substrate for optical discs or magneto optical discs.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |