Biaxially oriented film for electrical insulation and film capacitor made using biaxially oriented film for electrical insulation

• US 9,754,721 B2
• Filed: 10/26/2010
• Issued: 09/05/2017
• Est. Priority Date: 10/28/2009
• Status: Active Grant

• Current Assignee: Teijin DuPont Films Japan Ltd. (Teijin Limited)
• Original Assignee: Teijin DuPont Films Japan Ltd. (Teijin Limited)
• Inventors: Yoshida, Tetsuo
• Primary Examiner(s): Chen, Vivian
• Application Number:
  US13/504,778
• Publication Number:
  US 20120217040A1
• Time in Patent Office: 2,506 Days
• Field of Search: None
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 15/09 comprising polyesters
• CPC Class Codes: B32B 2250/03 3 layers
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 2255/205 Metallic coating
• CPC Class Codes: B32B 2255/26 Polymeric coating
• CPC Class Codes: B32B 2255/28 Multiple coating on one surface
• CPC Class Codes: B32B 2307/20 having particular electrical or magnetic properties, e.g. piezoelectric
• CPC Class Codes: B32B 2307/204 Di-electric
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2457/16 Capacitors
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/30 comprising vinyl (co)polymers; comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/302 comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08K 3/045 : Fullerenes
• CPC Class Codes: C08K 5/005 : Stabilisers against oxidation, heat, light, ozone
• CPC Class Codes: C08K 5/16 : Nitrogen-containing compounds C08K5/0091 takes precedence
• CPC Class Codes: C08K 5/20 : Carboxylic acid amides
• CPC Class Codes: C08K 7/16 : Solid spheres
• CPC Class Codes: C08L 2205/22 : Mixtures comprising a continuous polymer matrix in which are dispersed crosslinked particles of another polymer
• CPC Class Codes: C08L 25/06 : Polystyrene
• CPC Class Codes: C08L 2666/02 : Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 67/02 : Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 67/03 : the dicarboxylic acids and dihydroxy compounds having the carboxyl- and the hydroxy groups directly linked to aromatic rings
• CPC Class Codes: C08L 83/04 : Polysiloxanes
• CPC Class Codes: C09D 183/04 : Polysiloxanes
• CPC Class Codes: C09D 183/08 : containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen
• CPC Class Codes: H01B 3/30 : plastics; resins; waxes
• CPC Class Codes: H01B 3/421 : Polyesters
• CPC Class Codes: H01B 3/422 : Linear saturated polyesters derived from dicarboxylic acids and dihydroxy compounds
• CPC Class Codes: H01B 3/423 : Linear aromatic polyesters
• CPC Class Codes: H01B 3/442 : from aromatic vinyl compounds
• CPC Class Codes: H01B 3/46 : silicones
• CPC Class Codes: H01G 4/18 : of synthetic material, e.g. derivatives of cellulose H01G4/16 takes precedence
• CPC Class Codes: H01G 4/224 : Housing; Encapsulation
• CPC Class Codes: Y10T 428/254 : Polymeric or resinous material
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]

Abstract

Disclosed is a biaxially oriented film for electrical insulation having even better withstand voltage characteristics than before together with excellent film-forming properties. The biaxially oriented film for electrical insulation of the invention is a film that includes a substrate layer containing a crystalline thermoplastic resin as a main component. The substrate layer contains a phenolic stabilizer in an amount of 0.001 wt % or more and 3 wt % or less based on the weight of the substrate layer. The phenolic stabilizer is an alkylenebisamide-type hindered phenol.

Claims

1. A process for producing a film capacitor comprising forming the film capacitor with a biaxially oriented film for electrical insulation comprising a substrate layer containing crystalline thermoplastic resin as a main component, wherein the crystalline thermoplastic resin is a polyethylene naphthalene dicarboxylate alone or in combination with syndiotactic polystyrene,

wherein the polyethylene naphthalene dicarboxylate is present in an amount of 60 wt % or more based on the total amount of the crystalline thermoplastic resin,

wherein the film is characterized in that the substrate layer contains a phenolic stabilizer in an amount of 0.3 wt % or more and 1.5 wt % or less based on the weight of the substrate layer, and the phenolic stabilizer is an alkylene bisamide-type hindered phenol,

wherein the alkylene bisamide-type hindered phenol is N,N′

-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide],

wherein the film comprises a coating layer on one side or both sides of the substrate layer, the coating layer containing a silicone compound in an amount of 1 to 50 wt % based on the weight of the coating layer,

wherein the film further comprises a metal layer on the coating layer,

wherein the phenolic stabilizer is melt-kneaded with polymerized polyester,

wherein a breakdown voltage of the film at 25°

C. is 450V/μ

m or more.

2. The process according to claim 1, wherein the substrate layer contains spherical crosslinked polymeric resin particles (A) having an average particle size of 0.5 μ

m or more and 3.0 μ

m or less in an amount of 0.01 wt % or more and 1.5 wt % or less based on the weight of the substrate layer.

3. The process according to claim 2, wherein the substrate layer further contains inert particles (B) having an average particle size of 0.01 μ

m or more and less than 0.5 μ

m in an amount of 0.05 wt % or more and 2.0 wt % or less based on the weight of the substrate layer, the average particle size of the inert particles (B) being at least 0.4 μ

m smaller than the average particle size of the spherical crosslinked polymeric resin particles (A).

4. The process according to claim 3, wherein the inert particles (B) are spherical crosslinked polymeric resin particles (B1).

5. The process according to claim 4, wherein the spherical crosslinked polymeric resin particles (A) or (B1) are silicone resin particles.

6. The process according to claim 2, wherein the spherical crosslinked polymeric resin particles (A) are silicone resin particles.

7. The process according to claim 1, wherein the substrate layer contains a fullerene in an amount of 0.01 wt % or more and 1 wt % or less based on the weight of the substrate layer.

8. The process according to claim 1, wherein an average breakdown voltage of the film at 25°

C. obtained from 50 measurements is 450 V/μ

m or more with a standard deviation of 20 V/μ

m or less.

9. The process according to claim 1, wherein the substrate layer has a refractive index in the thickness direction nz of more than 1.505.

10. The process according to claim 1, wherein the substrate layer has a thickness of 0.2 μ

m or more and 5 μ

m or less.

11. The process according to claim 1, wherein the silicone compound has a reactive group.

12. A film capacitor made using a biaxially oriented film for electrical insulation comprising a substrate layer containing crystalline thermoplastic resin as a main component, wherein the crystalline thermoplastic resin is a polyethylene naphthalene dicarboxylate alone or in combination with syndiotactic polystyrene,

wherein the polyethylene naphthalene dicarboxylate is present in an amount of 60 wt % or more based on the total amount of the crystalline thermoplastic resin,

the film being characterized in that the substrate layer contains a phenolic stabilizer in an amount of 0.3 wt % or more and 1.5 wt % or less based on the weight of the substrate layer, and the phenolic stabilizer is an alkylenebisamide-type hindered phenol,

wherein the alkylene bisamide-type hindered phenol is N,N′

-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide],

the film comprising a coating layer on one side or both sides of the substrate layer, the coating layer containing a silicone compound in an amount of more than 20 wt % to 50 wt % based on the weight of the coating layer,

the film further comprising a metal layer on the coating layer,

wherein the phenolic stabilizer is melt-kneaded with polymerized polyester,

wherein a breakdown voltage of the film at 25°

C. is 450V/μ

m or more.

13. The film capacitor according to claim 12, wherein the coating layer contains a silicone compound in an amount of 40 to 50 wt % based on the weight of the coating layer.

14. The film capacitor according to claim 13, wherein no fullerene is present in the film.

15. The film capacitor according to claim 12, wherein the substrate layer contains the phenolic stabilizer in an amount of 0.49 wt % or more and 1.35 wt % or less based on the weight of the substrate layer.

16. The film capacitor according to claim 12, wherein the substrate layer contains the phenolic stabilizer in an amount of 0.49 wt % or more and 1.00 wt % or less based on the weight of the substrate layer.

17. The film capacitor according to claim 12, wherein the crystalline thermoplastic resin is present in an amount of 97 wt % or more based on the weight of the substrate layer.