Inorganic sheet laminate

• US 6,855,404 B2
• Filed: 03/13/2003
• Issued: 02/15/2005
• Est. Priority Date: 03/13/2003
• Status: Active Grant

• Current Assignee: DuPont Safety & Construction, Inc. (DuPont de Nemours, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Anderson, David Wayne, Kawka, Dariusz Wlodzimierz
• Primary Examiner(s): Chen, Vivian
• Application Number:
  US10/388,066
• Publication Number:
  US 20040180228A1
• Time in Patent Office: 705 Days
• Field of Search: 428/213, 428/430, 428/443, 428/446, 428/458, 428/480, 428/702, 428/426, 428/454, 428/457, 442/117, 442/172, 442/178, 442/179, 442/180, 442/286, 442/287, 442/295, 442/296, 442/394, 442/395, 442/376, 174/137.R, 174/110.R, 174/120.R, 174/121.R, 174/121.SR, 174/122.R, 174/122.G, 174/124.R, 174/124.G, 174/110.SR, 174/110.PM, 162/135, 162/138, 162/141, 162/145, 162/152, 162/153, 162/156, 162/161.1, 162/164.6, 162/181.1, 162/181.4, 162/181.6, 162/181.7, 162/181.8
• US Class Current: 428/213
• CPC Class Codes: B25B 13/5083 by internally gripping the pipe
• CPC Class Codes: B32B 2307/206 Insulating
• CPC Class Codes: B32B 2307/5825 Tear resistant
• CPC Class Codes: B32B 2309/105 Thickness
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2457/04 Insulators
• CPC Class Codes: B32B 27/10 of paper or cardboard
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 37/153 at least one layer is extruded and immediately laminated while in semi-molten state
• CPC Class Codes: B32B 5/22 characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed layer formed of natural mineral fibres or particles next to a foam layer B32B19/047, next to a layer made of particles B32B19/048, or next to a fibrous or filamentary layer B32B19/06; paper layer or cardboard layer next to a paper layer or cardboard layer B32B29/005, next to a foam layer B32B29/007, next to a fibrous or filamentary layer B32B29/02, or next to a particulate layer B32B29/04
• CPC Class Codes: B32B 5/28 impregnated with or embedded in a plastic substance not used
• CPC Class Codes: H01B 3/423 Linear aromatic polyesters
• CPC Class Codes: Y10T 156/1729 Fluid applied to nip between indefinite length webs
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/31616 Next to polyester [e.g., alkyd]
• CPC Class Codes: Y10T 428/31652 Of asbestos
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 442/2926 Coated or impregnated inorganic fiber fabric
• CPC Class Codes: Y10T 442/2975 Coated or impregnated ceramic fiber fabric
• CPC Class Codes: Y10T 442/2984 : Coated or impregnated carbon or carbonaceous fiber fabric
• CPC Class Codes: Y10T 442/2992 : Coated or impregnated glass fiber fabric
• CPC Class Codes: Y10T 442/3854 : Woven fabric with a preformed polymeric film or sheet
• CPC Class Codes: Y10T 442/3862 : Ester condensation polymer sheet or film [e.g., polyethylene terephthalate, etc.]
• CPC Class Codes: Y10T 442/3927 : Including a paper or wood pulp layer
• CPC Class Codes: Y10T 442/3935 : Mica paper layer
• CPC Class Codes: Y10T 442/674 : Nonwoven fabric with a preformed polymeric film or sheet
• CPC Class Codes: Y10T 442/675 : Ester condensation polymer sheet or film [e.g., polyethylene terephthalate, etc.]

Abstract

A laminate of inorganic sheet and polyester resin having an overall thickness of 5 to 25 mils and having an elongation at break in both the cross direction and machine direction of at least 25%.

Claims

1. A laminate of inorganic sheet and polyester resin having an overall thickness of 5 to 25 mils and having an elongation at break in both the cross direction and machine direction of at least 25%.

2. The laminate of claim 1 wherein the elongation at break in the cross direction is at least 30%.

3. The laminate of claim 2 wherein the thickness of the resin in the laminate is greater than the thickness of any individual inorganic sheet in the laminate.

4. The laminate of claim 1 wherein the inorganic sheet is a paper comprising an inorganic mineral, an inorganic reinforcement, and a binder.

5. The laminate of claim 4 wherein the inorganic mineral includes aluminum silicate.

6. The laminate of claim 4 wherein the inorganic reinforcement includes glass fiber.

7. The laminate of claim 4 wherein the binder includes acrylonitrile latex.

8. The laminate of claim 1 wherein the polyester resin is poly(ethylene terephthalate).

9. The laminate of claim 8 wherein the poly(ethylene terephthalate) includes a comonomer selected from the group of diethylene glycol, cyclohexanedimethanol, poly(ethylene glycol), glutaric acid, azelaic acid, sebacic acid, and isophthalic acid.

10. The laminate of claim 8 wherein the poly(ethylene terephthalate includes a branching agent selected from the group of trimesic acid, pyromellitic acid, trimethylolpropane, trimethyloloethane, and pentaerythritol.

11. The laminate of claim 1 wherein the polyester resin is poly(ethylene naphthalate).

12. The laminate of claim 1 wherein the polyester resin is sandwiched between two inorganic sheets.

13. The laminate of claim 12 wherein the polyester resin sandwiched between two inorganic sheets includes a layered combination of resins.

14. An electrical device containing an electrical conductor and an insulating laminate comprising inorganic sheet and polyester resin, said laminate having an overall thickness of 5 to 25 mils and having an elongation at break in both the cross direction and the machine direction of at least 25%.

15. The electrical device of claim 14 wherein the laminate has an elongation at break in the cross direction of at least 30%.

16. The electrical device of claim 14 which is a transformer.