US4662973A
Expired / Lapsed
US
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Continuous process for preparing reinforced resin laminates
Assignee: Kanegafuchi Chemical Industry Co Ltd
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Filing: 1982-12-20
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Granted: 1987-05-05
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Expires: 2002-12-20
Abstract
Abstract A continuous process for producing reinforced resin laminates is disclosed. A plurality of fibrous substrate is continuously and sequentially subjected to the steps of (a) impregnating with resin, (b) laminating into a unitary member, (c) sandwiching between a pair of covering sheet, at least one of which is a cladding metal foil, and (d) curing the resin while supporting between said covering sheets without applying pressure on the laminate surface.
Inventors
- 👤 Masana Gotou
- 👤 Minoru Isshiki
- 👤 Shoji Uozumi
- 👤 Masayuki Ohizumi
- 👤 Yasuo Fushiki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:36
CPC Classifications
B; B32; B32B; B32B38/00; B32B38/08; H; H05; H05K; H05K3/00; H05K3/02; H05K3/022; B32B2457/00; B32B2457/08; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; H05K1/036; H05K1/0366; H05K2203/00; H05K2203/06; H05K2203/068; H05K2203/15; H05K2203/1545; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
211 words
In a continuous process for preparing flat, rigid, reinforced resin laminate printed circuit board stock material comprising the steps of impregnating a plurality of fibrous substrate sheets with a liquid themosetting resin composition free of volatile components and capable of curing without generating a volatile byproduct; continuously combining a plurality of the resultant impregnated substrates into a continuous, unitary, multiple ply uncured laminate sheet; continuously sandwiching the uncured laminate sheet between a pair of continuous covering sheets, at least one of which is a cladding metal foil capable of adhering to the surface of the uncured laminate to form a continuous flat sandwich; and continuously curing the resultant sandwich to form a continuous sheet of printed circuit board stock material; the improvement which comprises: (a) thoroughly impregnating the substrate sheets with resin by continuously contacting the sheets individually and separately with excess resin; (b) continuously forming the resin-impregnated substrate sheets and cover sheets into a sandwich of a desired thickness while the resin is uncured; and (c) continuously curing the uncured sandwich in the absence of external compressive force thereon perpendicular to the plane of the sandwich to form a continuous sheet of the printed circuit board stock material having uniform thickness, electrical, dielectric, and heat resistant properties along its length.
Claim 2
Dependent Claim
211 words
In a continuous process for preparing flat, rigid, reinforced resin laminate printed circuit board stock material comprising the steps of impregnating a plurality of fibrous substrate sheets with a liquid themosetting resin composition free of volatile components and capable of curing without generating a volatile byproduct; continuously combining a plurality of the resultant impregnated substrates into a continuous, unitary, multiple ply uncured laminate sheet; continuously sandwiching the uncured laminate sheet between a pair of continuous covering sheets, at least one of which is a cladding metal foil capable of adhering to the surface of the uncured laminate to form a continuous flat sandwich; and continuously curing the resultant sandwich to form a continuous sheet of printed circuit board stock material; the improvement which comprises: (a) thoroughly impregnating the substrate sheets with resin by continuously contacting the sheets individually and separately with excess resin; (b) continuously forming the resin-impregnated substrate sheets and cover sheets into a sandwich of a desired thickness while the resin is uncured; and (c) continuously curing the uncured sandwich in the absence of external compressive force thereon perpendicular to the plane of the sandwich to form a continuous sheet of the printed circuit board stock material having uniform thickness, electrical, dielectric, and heat resistant properties along its length.
Claim 3
Dependent Claim
14 words
A process according to claim 1, wherein both covering sheets are cladding metal foils.
Claim 4
Dependent Claim
37 words
A process according to claim 1, wherein only one of the covering sheets is a cladding metal foil and the other covering sheet is continuously released from the printed circuit board stock material after the curing step.
Claim 5
Dependent Claim
16 words
A process according to claim 1, wherein the continuously releasing covering sheet is an endless belt.
Claim 6
Dependent Claim
15 words
A process according to claim 1, wherein the cladding metal foil is electrolytic copper foil.
Claim 7
Dependent Claim
18 words
A process according to claim 5, wherein the copper foil has been pre-coated with a silane coupling agent.
Claim 8
Dependent Claim
138 words
A process according to claim 1, wherein dry substrate sheets are pre-impregnated with an effective amount of up to 50% by weight of a composition selected from the group consisting of: (a) a silane coupling agent to improve the adhesion of the substrate to the resin; (b) polymerizable monomers or comonomers to increase resin impregnation speed; (c) a thermoplastic material to improve mechanical and/or electrical characteristics of the resulting laminate; (d) a solution of thermosetting resin or a prepolymer thereof to reduce moisture pick-up in the finished laminate; (e) ethylenically unsaturated aliphatic carboxylic acids to improve impregnation of the substrate with unsaturated polyester resin; (f) a hydrophobic reactant for the substrate to retard moisture pick-up of a hydrophobic substrate; (g) a curing catalyst followed by drying to prolong the pot life of liquid resin; and (h) inorganic fillers.
Claim 9
Dependent Claim
22 words
A process according to claim 1, wherein the substrate is impregnated by pouring the liquid resin onto only the upper side thereof.
Claim 10
Dependent Claim
23 words
A process according to claim 1, wherein the resin composition is capable of heat curing and the uncured sandwich is cured by heating.
Claim 11
Dependent Claim
20 words
A process according to claim 1, wherein the fibrous substrate is paper having a moisture content of less than 2%.
Claim 12
Dependent Claim
23 words
A process according to claim 10, wherein the paper substrate is continuously dried in a heating step prior to impregnation with the resin.
Claim 13
Dependent Claim
103 words
A process according to claim 10, further comprising pre-impregnating the paper substrate with an effective amount of up to 50% by weight of a composition selected from the group consisting of: (a) acrylate or methacrylate comonomers to increase resin impregnation speed; (b) polyethylene glycol to increase the impact strength of the finished resin laminate; (c) a solution of thermosetting resin or a prepolymer thereof to reduce moisture pick-up in the finished laminate; (d) a cellulose acylating agent to retard moisture pick-up of a hydrophilic substrate material; and (e) inorganic fillers and drying the pre-impregnated substrate when it is (b), (c), (d), or (e).
Claim 14
Dependent Claim
22 words
A process according to claim 10, wherein the substrate is impregnated by pouring the liquid resin onto only the upper side thereof.
Claim 15
Dependent Claim
14 words
A process according to claim 10, wherein the resin is an unsaturated polyester resin.
Claim 16
Dependent Claim
23 words
A process according to claim 14, wherein the resin composition is capable of heat curing and the uncured sandwich is cured by heating.
Claim 17
Dependent Claim
37 words
A process according to claim 15, wherein the polyester resin composition comprises (a) a condensate of a polyhydric alcohol with an unsaturated polycarboxylic acid and a saturated polycarboxylic acid, and (b) an ethylenically unsaturated, non-volatile crosslinking monomer.
Claim 18
Dependent Claim
12 words
A process according to claim 16, wherein the crosslinking monomer is styrene.
Claim 19
Dependent Claim
42 words
A process according to claim 17, wherein the substrate is five sheets of paper having a weight basis of about 150 g/m 2 , an air dried density of about 0.53 g/cm 3 , and a mean thickness of about 280 μm.
Claim 20
Dependent Claim
94 words
A process according to claim 18, wherein the resin composition consists essentially of (a) about 100 parts of liquid unsaturated polyester resin containing maleic acid:isophthalic acid:ethylene glycol in a molar ratio of about 82:18:100, a styrene monomer content of about 37%, and a viscosity at 25° C. of about 5 poise; (b) one part t-butylperoxy-2-ethylhexanoate; and (c) 0.2 parts 6% cobalt naphthenate, which is cured to a polyester resin film having a flexural modulus of 283 kg/mm 2 , a Rockwell hardness of about 106, and a glass transition temperature of about 90° C.
Claim 21
Dependent Claim
22 words
A process according to claim 18, further comprising pre-impregnating the substrate with an aqueous solution of methylolmelamine and drying the pre-impregnated substrate.
Claim 22
Dependent Claim
94 words
A process according to claim 20, wherein the resin composition consists essentially of (a) about 100 parts of liquid unsaturated polyester resin containing maleic acid:isophthalic acid:ethylene glycol in a molar ratio of about 82:18:100, a styrene monomer content of about 37%, and a viscosity at 25° C. of about 5 poise; (b) one part t-butylperoxy-2-ethylhexanoate; and (c) 0.2 parts 6% cobalt naphthenate, which is cured to a polyester resin film having a flexural modulus of 283 kg/mm 2 , a Rockwell hardness of about 106, and a glass transition temperature of about 90° C.
Claim 23
Dependent Claim
14 words
A process according to claim 1, wherein the fibrous substrate is a glass fabric.
Claim 24
Dependent Claim
97 words
A process according to claim 22, further comprising pre-impregnating the glass fabric substrate with an effective amount of up to 50% by weight of a composition selected from the group consisting of: (a) a silane coupling agent to improve the adhesion of the substrate to the resin; (b) ethylenically unsaturated aliphatic carboxylic acids to improve impregnation of the substrate with unsaturated polyester resin; (c) a curing catalyst followed by drying and pre-impregnation with epoxy resin free of the curing catalyst to prolong the pot life of liquid resin; and (d) inorganic fillers and drying the pre-impregnated substrate.
Claim 25
Dependent Claim
22 words
A process according to claim 22, wherein the substrate is impregnated by pouring the liquid resin onto only the upper side thereof.
Claim 26
Dependent Claim
13 words
A process according to claim 22, wherein the resin is an epoxy resin.
Claim 27
Dependent Claim
23 words
A process according to claim 25, wherein the resin composition is capable of heat curing and the uncured sandwich is cured by heating.
Claim 28
Dependent Claim
31 words
A process according to claim 26, wherein the epoxy resin is selected from the group consisting of Bisphenol A epoxy resins, Bisphenol F epoxy resins, epoxy novoloc resins, and mixtures thereof.
Claim 29
Dependent Claim
15 words
A process according to claim 24, wherein the substrate comprises eight plies of fiberglass fabric.
Claim 30
Dependent Claim
62 words
A process according to claim 28, wherein the epoxy resin composition consists essentially of 100 parts of a Bisphenol A type epoxy resin, 80 parts of methyl tetrahydrophthalic anhydride, and 0.5 parts of N,N-dimethylbenzylamine having a viscosity at 25° C. of about 6.5 poises, and wherein both sides of the sandwich are coated with an electrolytic copper foil to form the laminate.
Claim 31
Dependent Claim
67 words
A process according to claim 1, wherein step (b) is conducted by continuously combining the resin-impregnated substrate sheets into a continuous, unitary, multiple ply uncured laminate sheet by passage through a first pair of laminating rollers and continuously forming the uncured laminate sheet and cover sheets into a sandwich of a desired thickness by passage through a second pair of laminating rollers while the resin is uncured.
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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) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |