Method for forming bodies comprising previously crosslinked thermally stable resin and product made thereby

• US 5,256,361 A
• Filed: 05/22/1992
• Issued: 10/26/1993
• Est. Priority Date: 05/22/1992
• Status: Expired due to Fees

• Current Assignee: Cooper-Standard Automotive Incorporated (Cooper-Standard Holdings Incorporated)
• Original Assignee: The Standard Products Company (Goodyear Tire & Rubber Company)
• Inventors: Keys, James F.
• Primary Examiner(s): Thurlow, Jeffery
• Application Number:
  US07/887,311
• Time in Patent Office: 522 Days
• Field of Search: 264/236, 264/347, 264/211.24, 264/177.10, 264/177.17, 264/177.19, 264/339, 264/248, 264/261, 264/152, 156/221
• US Class Current: 264/236
• CPC Class Codes: B29C 65/00 Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326
• CPC Class Codes: B29C 65/70 by moulding using a particular moulding technique, see the relevant technique , e.g. by injection B29C45/14467
• CPC Class Codes: B29C 66/1142 Single butt to butt joints
• CPC Class Codes: B29C 66/52431 with a right angle, e.g. for making L-shaped pieces
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73754 the to-be-joined areas of both parts to be joined being partially cured
• CPC Class Codes: B29C 66/73941 characterised by the materials of both parts being thermosets
• CPC Class Codes: B29C 70/845 by moulding material on a relative small portion of the preformed parts
• CPC Class Codes: B29K 2009/00 Use of rubber derived from conjugated dienes, as moulding material
• CPC Class Codes: B29K 2011/00 Use of rubber derived from chloroprene as moulding material
• CPC Class Codes: B29K 2019/00 Use of rubber not provided for in a single one of main groups B29K2007/00 - B29K2011/00, as moulding material
• CPC Class Codes: B29K 2023/16 EPM, i.e. ethylene-propylene copolymers; EPDM, i.e. ethylene-propylene-diene copolymers; EPT, i.e. ethylene-propylene terpolymers
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2081/04 Polysulfides, e.g. PPS, i.e. polyphenylene sulfide or derivatives thereof
• CPC Class Codes: B29K 2083/00 Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
• CPC Class Codes: B29K 2105/24 crosslinked or vulcanised
• CPC Class Codes: B29K 2105/243 Partially cured
• CPC Class Codes: B29L 2031/26 Sealing devices, e.g. packaging for pistons or pipe joints
• CPC Class Codes: B60J 10/21 having corner parts or bends
• CPC Class Codes: Y10T 156/1043 : Subsequent to assembly

Abstract

A method of forming a body comprising resin material which can be crosslinked to form a thermally stable resin is carried out by the sequential steps of:

(A) providing a body of resin which can be crosslinked to form a thermally stable resin;

(B) selectively crosslinking said body to provide a first zone of substantially uncrosslinked resin; a zone of substantially crosslinked resin and a transition zone therebetween;

(C) forming said first zone and transition zone; and

(D) substantially crosslinking said first zone and transition zone.

Step (C) can be carried out by introducing a first zone and associated transition zone into a mold cavity in effective contacting relationship with second zone of substantially uncrosslinked resin and associated transition zone and then step (D) can be carried out to thereby bond said first and second zone together. The present invention also relates to the products made by the method of this invention.

Claims

1. A method of forming a body comprising resin material which can be crosslinked to form a thermally stable resin, said method comprising the sequential steps of

(A) providing a body of resin which can be crosslinked to form a thermally stable resin;

(B) selectively crosslinking said body to provide a first zone of substantially uncrosslinked resin;

a zone of substantially crosslinked resin and a transition zone therebetween;

(C) forming said first zone and transition zone; and

(D) substantially crosslinking said first zone and transition zone for providing a body substantially free of a visible joint line.

2. The method of claim 1 wherein step (A) is carried out by extruding said resin.

3. The method of claim 2 wherein step (B) is carried out by selectively heating said body.

4. The method of claim 3 wherein said first zone is sandwiched between two substantially crosslinked zones with a transition zone between said first zone and each one of said two substantially crosslinked zones.

5. The method of claim 4 wherein step (C) is carried out by compressing said first zone and associated transition zones in a mold cavity.

6. The method of claim 5 wherein said resin is rubber.

7. The method of claim 6 wherein said rubber is cis-1,4-polyisoprene, polybutadiene, poly(butadiene-co-styrene), poly(butadiene-co-acrylonitrile), poly(isobutylene-co-isoprene), poly(ethylene-co-propylene-co-diene), polychloroprene, polydimethylsiloxane, polyalkylenesulfide, polyester or polyether urethanes.

8. The method of claim 1 wherein said first zone is an end face portion of said body;

step (C) is carried out by placing said end face in effective contacting relationship with another said face; and

step (D) is carried out by crosslinking said faces into bonding relationship.

9. A method of bonding adjoining faces of a resin material which has been previously crosslinked to form a thermally stable resin comprises the steps of:

(A) providing first and second faces of substantially uncrosslinked resin, each of said faces having an associated body of resin which has been substantially crosslinked to a thermally stable condition and first and second transition zones between each respecting face and body;

(B) introducing said first and second faces, and said first and second transition zones into a mold cavity, said faces being placed in effective contacting relationship;

(C) substantially crosslinking the resin of said first and second faces and said first and second transition zones for forming a connection between said first and second faces substantially free of a visible joint line.

10. The method of claim 9 wherein step (A) is carried out by extruding a resin and then selectively curing said resin to provide said faces, transition zones and body.

11. The method of claim 9 wherein step (C) is carried out under conditions of heat and pressure.

12. The method of claim 10 wherein said resin is rubber.

13. The method of claim 12 wherein said rubber is EPDM.

14. The method of claim 10 wherein said faces are end faces of the same elongated extrudate body.

15. The method of claim 10 wherein said faces are facing portions of different extrudate pieces.

16. The method of claim 10 wherein said faces are bonded to form a T-joint.

17. The method of claim 9 wherein said faces are placed in abutting relationship in said mold.

18. The method of claim 9 wherein said faces are placed in effective contacting relationship by introducing into said mold additional substantially uncrosslinked resin material between said faces.