Thermal switch based on polymer compound

• US 10,450,490 B2
• Filed: 03/11/2016
• Issued: 10/22/2019
• Est. Priority Date: 03/12/2015
• Status: Active Grant

• Current Assignee: Total Research & Technology Feluy SA (Totalenergies Se)
• Original Assignee: Total Research & Technology Feluy SA (Totalenergies Se)
• Inventors: Lhost, Olivier, Rousseaux, Dimitri
• Primary Examiner(s): Kopec, Mark
• Assistant Examiner(s): Thomas, Jaison P
• Application Number:
  US15/557,420
• Publication Number:
  US 20180273822A1
• Time in Patent Office: 1,320 Days
• CPC Class Codes: B29C 48/022 characterised by the choice of material
• CPC Class Codes: B29C 48/78 Thermal treatment of the extrusion moulding material or of preformed parts or layers, e.g. by heating or cooling
• CPC Class Codes: B29C 67/24 characterised by the choice of material
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2025/06 PS, i.e. polystyrene
• CPC Class Codes: B29K 2105/0094 having particular viscosity
• CPC Class Codes: B29K 2105/162 Nanoparticles
• CPC Class Codes: B29K 2507/04 Carbon
• CPC Class Codes: B29K 2995/0005 Conductive
• CPC Class Codes: B29K 2995/0039 Amorphous
• CPC Class Codes: B29K 2995/004 Semi-crystalline
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C08J 2323/06 Polyethene
• CPC Class Codes: C08J 2325/04 Homopolymers or copolymers of styrene
• CPC Class Codes: C08J 2325/06 Polystyrene
• CPC Class Codes: C08J 2423/06 Polyethene
• CPC Class Codes: C08J 2425/06 Polystyrene
• CPC Class Codes: C08J 3/226 using a polymer as a carrier
• CPC Class Codes: C08K 2201/001 Conductive additives
• CPC Class Codes: C08K 2201/011 : Nanostructured additives
• CPC Class Codes: C08K 3/04 : Carbon
• CPC Class Codes: C08K 3/041 : Carbon nanotubes
• CPC Class Codes: C08K 3/046 : Carbon nanorods, nanowires, nanoplatelets or nanofibres
• CPC Class Codes: C08L 2203/20 : use in electrical or conductive gadgets
• CPC Class Codes: C08L 2205/025 : containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 23/06 : Polyethene
• CPC Class Codes: C08L 2310/00 : Masterbatches
• CPC Class Codes: C08L 25/06 : Polystyrene
• CPC Class Codes: C09K 5/14 : Solid materials, e.g. powdery or granular
• CPC Class Codes: H01B 1/24 : the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01C 17/00 : Apparatus or processes specially adapted for manufacturing resistors providing fillings for housings or enclosures H01C1/02; reducing insulation surrounding a resistor to powder H01C1/03; manufacture of thermally variable resistors H01C7/02, H01C7/04
• CPC Class Codes: H01C 17/0652 : containing carbon or carbides
• CPC Class Codes: H01C 17/06586 : composed of organic material
• CPC Class Codes: H01C 7/008 : Thermistors H01C7/02 - H01C7/06 take precedence
• CPC Class Codes: H01C 7/027 : consisting of conducting or semi-conducting material dispersed in a non-conductive organic material
• CPC Class Codes: Y10S 977/752 : Multi-walled
• CPC Class Codes: Y10S 977/753 : with polymeric or organic binder
• CPC Class Codes: Y10S 977/842 : for carbon nanotubes or fullerenes
• CPC Class Codes: Y10S 977/955 : Of thermal property

Abstract

The present invention relates to an article suitable to act as a thermal switch device, the article having a surface resistance of more than 10⁵ ohms and formed from a polymer composition comprising from 50 to 99.9 wt % relative to the total weight of the polymer composition, of a polymer being selected from an amorphous polymer having a glass transition temperature Tg, a semi-crystalline polymer having a melting temperature Tm or a mixture thereof, and from 0.1 to 50 wt % relative to the total weight of the polymer composition, of a conductive material, wherein the surface resistance of the article is divided by at least 10, preferably by at least 100, when said article is submitted for a determined period of time of less than 5 minutes to a temperature of switch i) ranging from Tg+10° C. to Tg+250° C. if the polymer composition comprises an amorphous polymer, or ii) ranging from Tm−80° C. to Tm+250° C. if the polymer composition comprises a semi-crystalline polymer.

Claims

1. An article suitable to act as a thermal switch device, the article having a surface resistance of more than 10⁵ ohms as determined according to ASTM D257-07, and being formed from a polymer composition, said polymer composition comprising

from 50 to 99.9 wt % relative to the total weight of the polymer composition, of a polymer being selected from an amorphous polymer having a glass transition temperature Tg, a semi-crystalline polymer having a melting temperature Tm or a mixture thereof, and

from 0.1 to 50 wt % relative to the total weight of the polymer composition, of a conductive material;

wherein the surface resistance of the article is divided by at least 10, when said article is submitted for a determined period of time of less than 5 minutes to a temperature switch

i) ranging from Tg+10°

C. to Tg+250°

C. if the polymer composition comprises an amorphous polymer,

ii) ranging from Tm−

80°

C. to Tm+250°

C. if the polymer composition comprises a semi-crystalline polymer,

iii) ranging from Tg+10°

C. to Tg+250°

C. if the polymer composition comprises a mixture of amorphous and semi-crystalline polymers and the amorphous polymer forming the continuous polymeric phase, or

iv) ranging from Tm−

80°

C. to Tm+250°

C. if the polymer composition comprises a mixture of amorphous and semi-crystalline polymers and the semi-crystalline polymer forming the continuous polymeric phase.

2. The article according to claim 1, wherein the conductive material of the polymer composition is selected from the group consisting of carbon nanotubes, carbon nanofibers, carbon black, metal fibers, metal powders and blends thereof.

3. The article according to claim 1, wherein the polymer composition comprises an amorphous polymer, wherein the amorphous polymer is selected from polystyrene (PS), atactic polypropylene (aPP), acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), styrene acrylonitrile (SAN), poly(methyl methacrylate) (PMMA), poly(vinyl chloride) (PVC), polybutadiene (PBu), polybutylene terephthalate (PBt), poly(p-phenylene oxide) (PPO), polysulfone (PSU), polyethersulfone (PES), polyethylenimine (PEI), polyphenylsulfone (PPSU), acrylonitrile styrene acrylate (ASA) or any combination thereof.

4. The article according to claim 1, wherein the polymer composition comprises an semi-crystalline polymer, and wherein the semi-crystalline polymer is selected from polyamide, homo- and co-polymer of ethylene (PE), homo- and co-polymer of propylene (PP), impact copolymer of propylene (IPP), Polylactide (PLA), polyether ether ketone (PEEK), polyoxymethylene (POM), syndiotactic polystyrene (sPS), polyphenylene sulfide (PPS), liquid crystalline polymers (LCP), homo- and co-polymer of butane, homo- and co-polymer of hexene, ethylene vinyl acetate (EVA), polyurethane or any combination thereof.

5. The article according to claim 1, wherein the surface resistance of the article is divided by at least 10, when said article is submitted for a determined period of time of less than 5 minutes to temperature switch

i) ranging from Tg+75°

C. to Tg+250°

C. if the polymer composition comprises an amorphous polymer.

6. The article according to claim 5 wherein the surface resistance of the article is divided by at least 10, when said article is submitted for less than 2 minutes to the temperature switch.

7. The article according to claim 1, wherein the polymer composition comprises at least 0.5 wt % relative to the total weight of the polymer composition, of the conductive material.

8. The article according to claim 1 having a thermal conductivity higher than 0.4 W/(m*K).

9. The article according to claim 1, wherein the article is a film, a sheet, a formed sheet, a pipe or an injected article.

10. A process to produce an article suitable to act as a thermal switch device according to claim 1, comprising the step of:

a) providing a polymer composition having a surface resistance of less than 10⁴ ohms, said polymer composition comprising;

from 50 to 99.9 wt % relative to the total weight of the polymer composition, of a polymer being selected from an amorphous polymer having a glass transition temperature Tg, a semi-crystalline polymer having a melting temperature Tm or a mixture thereof, and

from 0.1 to 50 wt % relative to the total weight of the polymer composition, of a conductive material;

b) forming or pre-forming an article; and

c) cooling the article by contact with a cooling device system or medium using a temperature of at least Tg−

20°

C. if the polymer composition comprises an amorphous polymer or at least Tm−

20°

C. if the polymer composition comprises a semi-crystalline polymer.

11. A process according to claim 10, wherein the step b) of forming or performing the article is made by extrusion or injection.

12. A process according to claim 10, wherein the step c) comprises cooling the article by a cooling device system using a temperature ranging from Tg−

20°

C. to Tg−

150°

C. if the polymer composition comprises an amorphous polymer, ranging from Tm−

20°

C. to Tm−

150°

C. if the polymer composition comprises a semi-crystalline polymer, ranging from Tg+10°

C. to Tg+250°

C. if the polymer composition comprises a mixture of amorphous and semi-crystalline polymers and the amorphous polymer forming the continuous polymeric phase, or ranging from Tm−

80°

C. to Tm+250°

C. if the polymer composition comprises a mixture of amorphous and semi-crystalline polymers and the semi-crystalline polymer forming the continuous polymeric phase.

13. A process according to claim 10, the process comprising a step b) of pre-forming the article resulting in a pre-formed article wherein the process further comprises after step c), a step d) of forming the article from the preformed article at a temperature less than Tg when the polymer composition comprises an amorphous polymer, less than Tm when the polymer composition comprises a semi-crystalline polymer, at a temperature less than Tg when the polymer composition comprises a mixture of amorphous and semi-crystalline polymers and the amorphous polymer forming a continuos polymeric phase, or at a temperature less than Tm when the polymer composition comprises a mixture of amorphous and semi-crystalline polymers and the semi-crystalline polymer forming the continuous polymeric phase.