Patent EP0315407A2 successfully refreshed from Google Patents.
EP0315407A2
Expired / Lapsed
EP
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High temperature release sheet for printed circuit boards
Assignee: DuPont Canada Inc
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Filing: 1988-11-01
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Granted: —
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Expires: 2008-11-01
Abstract
Abstract A process and nylon release sheet for manufacturing printed circuit boards from epoxy prepregs is disclosed. In such process layers of the prepregs are separated from one another by a release sheet. The release sheet comprises an aliphatic or aromatic nylon or nylon copolymer which is a condensation product of a dicarboxylic acid and a diamine. The nylon film contains a heat stabilizer and an inorganic particulate antiblock additive, e.g. diatomaceous earth, glass beads, amorphous silica, talc, mica and molybdenum disulphide. The nylon may be toughened by the addition of a phosphorus-containing catalyst or an epoxide.
Inventors
- 👤 Peter Andrew Sipos
- 👤 Erica Marie-Jose Besso
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 14:52
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B29; B29C; B29C33/00; B29C33/56; B29C33/68; B29C37/00; B29C37/0067; B29C37/0075; C08K; C08K3/00; C08K3/01; H; H05; H05K; H05K3/00; H05K3/02; H05K3/022; C08J2377/00; C08J2377/06; H05K2203/00; H05K2203/06; H05K2203/068
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
A process for the manufacture of printed circuit boards from epoxy prepregs, wherein a release sheet is used in such manufacture, characterised in that the release sheet is formed from a nylon composition selected from i) a condensation product of a dicarboxylic acid and a diamine and ii) a copolymer of such condensation product, wherein said nylon contains effective amounts of an inorganic particulate anti-block additive and a heat stabilizer, and wherein the release sheet has an effective relative viscosity of at least 50 and is substantially unoriented.
Claim 2
Dependent Claim
88 words
A process for the manufacture of printed circuit boards from epoxy prepregs, wherein a release sheet is used in such manufacture, characterised in that the release sheet is formed from a nylon composition selected from i) a condensation product of a dicarboxylic acid and a diamine and ii) a copolymer of such condensation product, wherein said nylon contains effective amounts of an inorganic particulate anti-block additive and a heat stabilizer, and wherein the release sheet has an effective relative viscosity of at least 50 and is substantially unoriented.
Claim 3
Dependent Claim
34 words
A process according to Claim 1 wherein the nylon has been toughened by the addition of a phosphorus-containing catalyst selected from: hypophosphorous acid, phosphoric acid, phosphonic acid, phosphonic acid esters and metallic salts thereof.
Claim 4
Dependent Claim
90 words
A process according to Claim 1 wherein the nylon has been toughened by the addition of an epoxide cross-linking agent selected from 0.01 to 2 wt % of the epoxide and up to 0.5 wt % of an acidic catalyst; the epoxide being selected from: polyglycol diepoxides, bisphenol-A diepoxides, glycidyl ethers, tetraglycidyl esters, and bisphenol-F diepoxides; and the acidic catalyst being selected from the group consisting of sodium hypophosphite, manganese hypophosphite, orthophosphoric acid, sodium phenyl phosphate, phosphine/boron trifluoride complex, potassium phosphate, potassium hydroxide and aliphatic carboxylic acids, and mixtures thereof.
Claim 5
Dependent Claim
28 words
A process according to any one of the preceding claims wherein the anti-block additive is selected from diatomaceous earth, glass beads, amorphous silica, talc, mica and molybdenum disulphide.
Claim 6
Dependent Claim
31 words
A process according to any one of the preceding claims wherein thc heat stabilizer is a combination of a) a copper salt of an alkanoic acid and b) an inorganic halide.
Claim 7
Dependent Claim
35 words
A proess according to any one of claims 1 to 4 wherein the heat stabilizer is an antioxidant selected from hindered phenolic antioxidants, and a mixture of a hindered phenolic antioxidant and a secondary antioxidant.
Claim 8
Dependent Claim
53 words
A process according to Claim 6 wherein the hindered phenolic antioxidant is selected from 1,3,5 trimethyl-2,4,6,tris(3,5-di-tert-butyl-4-hydroxybenzyl) benzene, octadecyl-3,5,di-tert-butyl-4-hydroxy cinnamate, tetrakis-methylene-3-(3,5-di-tert-butyl-4-hydroxy-phenyl) propionate methane, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,5-di-tert-butyl hydroquinone, 2,2-methyl-bis(4-methyl-6-tert-butyl phenol), 2,2-methylene-bis(4-ethyl-6-tert-butyl phenol), 4,4-butylidene-bis(6-tert-butyl-m-cresol) and N,N-hexamethylene bis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide and the secondary antioxidant is selected from di (stearyl)pentaerythritol diphosphite, tris(2,4-di-tert-butyl phenyl) phosphite, dilauryl thiodipropionate and bis (2,4-di-tert-butyl) pentaerythritol diphosphite.
Claim 9
Dependent Claim
52 words
A nylon composition selected from i) a condensation product of a dicarboxylic acid and a diamine and ii) a copolymer of such condensation product, wherein said nylon composition contains an inorganic particulate anti-block additive and a heat stabilizer, and wherein the nylon composition has an effective relative viscosity of at least 50.
Claim 10
Dependent Claim
52 words
A nylon composition selected from i) a condensation product of a dicarboxylic acid and a diamine and ii) a copolymer of such condensation product, wherein said nylon composition contains an inorganic particulate anti-block additive and a heat stabilizer, and wherein the nylon composition has an effective relative viscosity of at least 50.
References Cited (Backward Citations)
No citation records indexed.
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