Process for the production of laminates utilizing pre-treating followed by impregnation

• US 3,897,588 A
• Filed: 02/09/1973
• Issued: 07/29/1975
• Est. Priority Date: 02/12/1972
• Status: Expired due to Term

• Current Assignee: Touru Nohtomi
• Original Assignee: Touru Nohtomi
• Inventors: Nohtomi, Touru
• Primary Examiner(s): Drummond, Douglas J.
• Assistant Examiner(s): Dawson, Robert A.
• Application Number:
  US05/331,030
• Time in Patent Office: 900 Days
• Field of Search: 156/309,335,330 161/93,155,170,193,196,198,DIG.4,186,DIG.7 162/145
• US Class Current: 428/436
• CPC Class Codes: B32B 2260/021 Fibrous or filamentary layer
• CPC Class Codes: B32B 2260/046 Synthetic resin
• CPC Class Codes: B32B 2262/062 Cellulose fibres, e.g. cotton
• CPC Class Codes: B32B 2262/101 Glass fibres
• CPC Class Codes: B32B 2307/306 Resistant to heat
• CPC Class Codes: B32B 2307/734 Dimensional stability
• CPC Class Codes: B32B 5/08 the fibres or filaments of a layer being of different substances , e.g. conjugate fibres, mixture of different fibres
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: D21H 11/04 Kraft or sulfate pulp
• CPC Class Codes: D21H 11/12 Pulp from non-woody plants or crops, e.g. cotton, flax, straw, bagasse
• CPC Class Codes: D21H 13/40 vitreous, e.g. mineral wool, glass fibres
• CPC Class Codes: D21H 17/46 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: D21H 17/47 Condensation polymers of aldehydes or ketones
• CPC Class Codes: D21H 19/04 applied as foil
• CPC Class Codes: D21H 27/30 Multi-ply for surface covering D21H27/18; making on paper-making machines D21F9/00, D21F11/00
• CPC Class Codes: H05K 1/036 Multilayers with layers of different types
• CPC Class Codes: H05K 1/0366 reinforced, e.g. by fibres, fabrics H05K1/036 takes precedence
• CPC Class Codes: H05K 2201/0166 Polymeric layer used for special processing, e.g. resist for etching insulating material or photoresist used as a mask during plasma etching
• CPC Class Codes: H05K 2201/0284 Paper, e.g. as reinforcement
• CPC Class Codes: H05K 2201/0293 Non-woven fibrous reinforcement
• CPC Class Codes: H05K 2201/0355 : Metal foils
• CPC Class Codes: H05K 2203/1476 : Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning
• CPC Class Codes: Y10S 428/901 : Printed circuit
• CPC Class Codes: Y10T 428/31529 : Next to metal
• CPC Class Codes: Y10T 428/31627 : Next to aldehyde or ketone condensation product

Abstract

A process for the production of laminates composed of sheets made of cellulose and glass fibers by pre-treating the sheets with a melamine resin or a methylol group-rich phenolic resin, impregnating the pre-treated sheets with a thermosetting resin and then laminating the impregnated sheets to produce the laminates. In one embodiment, the laminates are covered with a resin-treated glass fabric on at least one of the outermost surfaces or are further covered with a copper foil on the glass fabric-covered surface.

Claims

1. A PROCESS FOR THE PRODUCTION OF LAMINATES COMPRISING THE STEPS OF:

PRE-TREATING GLASS-CELLULOSE SHEETS COMPOSED OF 20-70% BY WEIGHT OF CELLULOSIC FIBERS AND 30-80% BY WEIGHT OF GLASS FIBERS WITH AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF MELAMINE RESINS PREPARED FROM FORMALDEHYDE AND MELAMINE IN A MOLAR RATIO OF FROM 1 TO 6 IN THE PRESENCE OF AN ACID CATALYST, AND METHYLOL GROUP-RICH PHENOLIC RESINS PREPARED FROM FORMALDEHYDE AND PHENOL IN A MOLAR RATIO OF FROM 1.3 TO 3.0 IN THE PRESENCE OF AN ALKALI CATALYST, IMPREGNATING THE PRE-TREATED SHEETS WITH AN EPOXY RESIN, DRYING THE IMPREGNATED SHEETS TO FORM PREPREGS THEREOF, ARRANGING THE PREPREGS FOR LAMINATION, PLACING ON THE OUTERMOST ONES OF THE ARRANGED PREPREGS A GLASS FABRIC PREVIOUSLY TREATED WITH THE EPOXY RESIN AS USED IN THE IMPREGNATION STEP, AND LAMINATING THE ARRANGED PREPREGS WITH THE RESIN-TREATED GLASS FABRIC ON THE OUTERMOST PREPREGS TO PRODUCE THE LAMINATE.

2. A process for the production of metal-clad laminates comprising the steps of:

pretreating glass-cellulose sheets composed of 20-70% by weight of cellulosic fibers and 30-80% by weight of glass fibers with at least one member selected from the group consisting of melamine resins prepared from formaldehyde and melamine in a molar ratio of from 1 to 6 in the presence of an acid catalyst, and methylol group-rich phenolic resins prepared from formaldehyde and phenol in a molar ratio of from 1.3 to 3.0 in the presence of an alkali catalyst, impregnating the pre-treated sheets with a thermosetting synthetic resin, drying the impregnated sheets to form prepregs thereof, arranging the prepregs for lamination, placing on the outer surface of each of the outermost ones of the arranged prepregs a glass fabric previously treated with the same thermosetting synthetic resin as used in the impregnating step, covering with a metal foil the outer surface of at least one of the glass fabrics placed on said outermost prepregs, and laminating the prepregs, glass fabrics and metal foil or foils so position to produce the metal-clad laminate.

3. A process for the production of laminates according to claim 1, wherein the amount of resin impregnated into the sheets in the pre-treating step is from 20 to 70% by weight of the sheets.

4. A process for the production of laminates aCcording to claim 1, wherein the total amount of resins impregnated into the sheets in the pre-treating and impregnating steps is from 30 to 80% by weight of the prepregs.

5. A process for the production of metal-clad laminates according to claim 2, wherein the amount of resin impregnated into the sheets in the pre-treating step is from 20 to 70% by weight of the sheets.

6. A process for the production of metal-clad laminates according to claim 2, wherein the total amount of resins impregnated into the sheets in the pre-treating and impregnating steps is from 30 to 80% by weight of the prepregs.

7. A process for the production of laminates according to claim 1, wherein the amount of resin impregnated into the glass fabric is from 20 to 80% by weight thereof.

8. A process for the production of metal-clad laminates according to claim 2, wherein the amount of resin impregnated into the glass fabric is from 20 to 80% by weight thereof.

9. A process for the production of laminates according to claim 1, wherein the methylol group-rich phenolic resins have 1.7 to 2.7 methylol groups in the nucleus.

10. A process for the production of metal-clad laminates according to claim 2, wherein the methylol group-rich phenolic resins have 1.7 to 2.7 methylol groups in the nucleus.

11. A process for the production of metal-clad laminates according to claim 2, wherein the thermosetting used in the impregnating step is an epoxy resin.

12. A process for the production of metal-clad laminates according to claim 2, wherein the metal foil is selected from the group consisting of copper and nickel.

13. A process for the production of laminates according to claim 1, wherein the glass-cellulose sheets are composed of 20 to 60% by weight of cellulose fibers and 40 to 80% by weight of glass fibers.

14. A process for the production of metal-clad laminates according to claim 2, wherein the glass-cellulose sheets are composed of 20 to 60% by weight of cellulose fibers and 40 to 80% by weight of glass fibers.

15. A process for the production of laminates according to claim 1, wherein the methylol group-rich phenolic resins are prepared from formaldehyde and phenol in a molar ratio of 1.5 to 3.0 in the presence of alkali catalyst.

16. A process for the production of metal-clad laminates according to claim 2, wherein the methylol group-rich phenolic resins are prepared from formaldehyde and phenol in a molar ratio of 1.5 to 3.0 in the presence of alkali catalyst.

17. A METAL-CLAD LAMINATE OBTAINED BY THE PROCESS OF CLAIM 2.

18. A process according to claim 1 including the step of drying said glass cellulose sheets after said pre-treating step and before said impregnating step.

19. A process according to claim 2 including the step of drying said glass cellulose sheets after said pre-treating step and before said impregnating step.