FLEXIBLE MOLDED SKIN

• US 20190084518A1
• Filed: 03/13/2018
• Published: 03/21/2019
• Est. Priority Date: 09/14/2015
• Status: Active Grant

• Current Assignee: MCPP Belgium BVBA (Mitsubishi Chemical Group Corp.), MCPP Innovation, LLC (Mitsubishi Chemical Group Corp.)
• Original Assignee: MCPP Belgium BVBA (Mitsubishi Chemical Group Corp.), MCPP Innovation, LLC (Mitsubishi Chemical Group Corp.)
• Inventors: BUSSELS, Raf, Bouwman, Ben, Trekels, Benny, Bemelmans, Stefan
• Granted Patent: US 10,640,071 B2
• Time in Patent Office: Days
• CPC Class Codes: B29C 41/003 characterised by the choice of material
• CPC Class Codes: B29C 41/18 Slush casting, i.e. pouring moulding material into a hollow mould with excess material being poured off
• CPC Class Codes: B29K 2027/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2105/16 Fillers
• CPC Class Codes: B29K 2509/00 Use of inorganic materials not provided for in groups B29K2503/00 - B29K2507/00, as filler
• CPC Class Codes: B29L 2031/3005 Body finishings
• CPC Class Codes: B29L 2031/3038 Air bag covers
• CPC Class Codes: B29L 2031/3041 Trim panels
• CPC Class Codes: B32B 2264/10 Inorganic particles
• CPC Class Codes: B32B 2264/203 Expanded, porous or hollow particles
• CPC Class Codes: B32B 2605/003 Interior finishings
• CPC Class Codes: B32B 27/065 of foam
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/304 comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: B32B 3/266 characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: B60R 21/2165 characterised by a tear line for defining a deployment opening
• CPC Class Codes: C08J 2327/06 Homopolymers or copolymers of vinyl chloride
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08J 9/0066 : Use of inorganic compounding ingredients
• CPC Class Codes: C08J 9/04 : using blowing gases generated by a previously added blowing agent
• CPC Class Codes: C08J 9/32 : from compositions containing microballoons, e.g. syntactic foams
• CPC Class Codes: C08K 2003/3045 : Sulfates
• CPC Class Codes: C08K 2201/005 : Additives being defined by their particle size in general
• CPC Class Codes: C08K 3/26 : Carbonates; Bicarbonates
• CPC Class Codes: C08K 3/30 : Sulfur-, selenium- or tellurium-containing compounds
• CPC Class Codes: C08K 3/34 : Silicon-containing compounds
• CPC Class Codes: C08K 3/346 : Clay
• CPC Class Codes: C08K 5/0016 : Plasticisers
• CPC Class Codes: C08K 5/11 : of acyclic polycarboxylic acids
• CPC Class Codes: C08K 5/12 : of cyclic polycarboxylic acids
• CPC Class Codes: C08K 7/16 : Solid spheres
• CPC Class Codes: C08L 27/06 : Homopolymers or copolymers of vinyl chloride

Abstract

The present invention relates to a flexible molded skin as part of a composite structure for an airbag cover, and to a composition for producing such a skin using slush molding. The composition and flexible molded skin have a thermoplastic plasticized vinyl polymer, and a tear promoting agent selected from the group of one or more particulate blowing agents, inorganic mineral materials, organic filler materials and microspheres or a mixture of two or more of the afore mentioned materials. The particles of the particulate tear promoting agent have an average particle size of between 0.005 and 50 μm, preferably between 0.005 and 40 μm.

Claims

1. A flexible molded skin for an airbag cover, wherein the skin comprises a sheet of a plasticized thermoplastic vinyl polymer material having particles of a tear promoting agent dispersed therein, wherein the particles of the tear promoting agent have a melting temperature above the melting temperature of the vinyl polymer material, wherein the tear promoting agent is contained in the sheet of plasticized thermoplastic vinyl polymer material in an amount of at least 0.1 wt. % and of maximum 7.5 wt. % such that the sheet of plasticized thermoplastic vinyl polymer material has an elongation at break of between 200.0% and 400.0% at room temperature measured according to ISO 527 part 1 and 2 test piece 5A, and a trouser tear strength of maximum 25 N/mm measured according to ISO 34-1 Method A.

2. A flexible molded skin as claimed in claim 1, wherein the sheet of plasticized thermoplastic vinyl polymer material has an elongation at break of at least 215%.

3. A flexible molded skin as claimed in claim 1, wherein the sheet of plasticized thermoplastic vinyl polymer material has an elongation at break of maximum 375%.

4. A flexible molded skin as claimed in claim 1, wherein the sheet of plasticized thermoplastic vinyl polymer material has a trouser tear strength of maximum 22.5 N/mm.

5. A flexible molded skin as claimed in claim 1, wherein the sheet of plasticized thermoplastic vinyl polymer material has a trouser tear strength of at least 5 N/mm.

6. A flexible molded skin as claimed in claim 5, wherein the sheet of plasticized thermoplastic vinyl polymer material has a trouser tear strength of at least 7.5 N/mm.

7. A flexible molded skin as claimed in claim 1, wherein the sheet of plasticized thermoplastic vinyl polymer material has a tensile strength of between 2 and 11 N/mm2, measured according to ISO 527 part 2 test piece 5A.

8. A flexible molded skin as claimed in claim 1, wherein the particles of the tear promoting agent are selected from the group consisting of particulate blowing agents, inorganic mineral materials, organic filler materials and microspheres and mixtures of two or more thereof.

9. A flexible molded skin as claimed in claim 1, wherein the particles of the tear promoting agent have an average particle size of between 0.005 and 50 μ

m.

10. A flexible molded skin as claimed in claim 1, wherein the sheet of plasticized thermoplastic vinyl polymer material contains at least 0.5 wt. % and less than 5.0 wt %, with respect to the weight of the sheet of the tear promoting agent.

11. A flexible molded skin as claimed in claim 10, wherein the sheet of plasticized thermoplastic vinyl polymer material contains at least 1.0 wt. % and less than 4.0 wt %, with respect to the weight of the sheet of the tear promoting agent.

12. A flexible molded skin as claimed in claim 1, wherein the tear promoting agent is an inorganic mineral material and the particles of the mineral tear promoting agent have an elongated shape.

13. A flexible molded skin as claimed in claim 12, wherein an aspect ratio of the largest dimension of the particles of the tear promoting agent with respect to the smallest dimension of the particles is at least 5.

14. A flexible molded skin as claimed in claim 13, wherein an aspect ratio of the largest dimension of the particles of the tear promoting agent with respect to the smallest dimension of the particles is at least 10.

15. A flexible molded skin as claimed in claim 12, wherein the tear promoting agent comprises one or more inorganic mineral materials selected from the group consisting of silicates, aluminosilicates, magnesium silicates, carbonates such as magnesium aluminum carbonates and mixtures of two or more thereof.

16. A flexible skin as claimed in claim 12, wherein the particles with an elongated shape have an aspect ratio of at least 5.0 and are contained in the flexible molded skin in an amount of at least 0.5 wt. and maximum 4.0 wt. %, with respect to the total weight of the sheet of plasticized thermoplastic vinyl polymer material.

17. A flexible molded skin as claimed in claim 1, wherein the tear promoting agent comprises one or more inorganic materials with an aspect ratio of maximum 5.0 selected from the group consisting of titanium dioxide, chalk, calcium sulfate, barium sulfate and mixtures of two or more thereof and are contained in the flexible molded skin in an amount of at least 2.0 wt. %, and less than 7.5 wt. % with respect to the weight of the sheet of plasticized thermoplastic vinyl polymer material.

18. A flexible molded skin as claimed in claim 1, wherein the tear promoting agent comprises one or more core shell materials having an aspect ratio of maximum 5.0, made of a first polymer of a soft rubber core, grafted with at least one second polymer of a different composition.

19. A flexible molded skin as claimed in claim 18, wherein the concentration of the core shell materials in the sheet of plasticized thermoplastic vinyl polymer material is at least 0.1 wt. %, and is maximum 7.5 wt %, with respect to the weight of the sheet of plasticized thermoplastic vinyl polymer material.

20. A flexible molded skin as claimed in claim 19, wherein the concentration of the core shell materials in the sheet of plasticized thermoplastic vinyl polymer material is at least 0.5 wt. %, and is maximum 7.5 wt %, with respect to the weight of the sheet of plasticized thermoplastic vinyl polymer material.

21. A flexible molded skin as claimed in claim 1, wherein the tear promoting agent comprises expandable microspheres, having a shell of an expandable thermoplastic material filled with a blowing agent and an aspect ration of maximum 5.0.

22. A flexible molded skin as claimed in claim 19, wherein the concentration of the expandable microspheres in the flexible molded skin is at least 0.05 by weight, and maximum 7.5 wt. %, with respect to the weight of the sheet of plasticized thermoplastic vinyl polymer material.

23. A flexible molded skin as claimed in claim 1, wherein the plasticized vinyl polymer comprises polyvinylchloride, optionally having a K value of at least 50 and a maximum of 80.

24. A flexible molded skin as claimed in claim 1, wherein sheet of plasticized thermoplastic vinyl polymer material contains from 30-50 wt. %, of at least one plasticizer composition.

25. A flexible molded skin as claimed in claim 24, wherein the plasticizer composition comprises a monomeric compound selected from the group consisting of azelates, trimellitates, sebacates, adipates, phthalates, citrates, benzoates, tallates, glutarates, fumarates, maleates, oleates, palmitates and acetates.

26. A flexible molded skin as claimed in claim 22, wherein the plasticizer composition contains at least 10 wt. % relative to the total amount of plasticizer of a polymeric plasticizer or a heavy molecular weight monomeric plasticizer, having a molecular weight of at least 350.

27. A flexible molded skin as claimed claim 1, comprising a weakening line which extends through part of a thickness of the skin.

28. A laminate, comprising a rigid carrier comprising an opening for receiving at least one airbag, wherein to at least part of one side of the rigid carrier a layer of a polymer foam is adhered, and wherein at least part of a side of the polymer foam layer opposite the side facing the carrier, is adhered to a flexible molded skin as claimed in claim 1.

29. A laminate according to claim 26, wherein the polymer foam is a polyurethane foam or a PVC foam.

30. A laminate according to claim 26, wherein the flexible molded skin comprises a material weakening line at a position which corresponds to an edge delimiting the airbag opening in the rigid carrier.

31. A laminate according to claim 26, wherein the airbag opening is substantially U-shaped, H-shaped or double Y-shaped.

32. A process for producing a flexible molded skin according to claim 1, wherein a mixture is produced comprising particles of a thermoplastic vinyl polymer material, particles of a tear promoting agent and a plasticizer, wherein the mixture is supplied to a mold of a slush molding device, wherein the mold is heated to a temperature of between 200 and 250°

C. and the mixture is subjected to slush molding to plasticize the vinyl polymer and produce a flexible skin, after which the flexible skin is removed from the mold and left to cool.

33. A process according to claim 32, wherein the mixture contains 0.1-7.5 wt. % of particles of a tear promoting agent and 30.0-50.0 wt. % of a plasticizer.

34. A composition for producing a flexible skin as claimed in claim 1, wherein the composition comprises 30.0-50.0 wt. % of a plasticizer, 0.1 to 7.5 wt. % of particles of at least one tear promoting agent, 40.0-60.0 wt. % of one or more vinyl polymers, and 1.0-20.0 wt. % of the usual remaining additives.

35. A flexible molded skin for an airbag cover, wherein the skin comprises a sheet of a plasticized thermoplastic vinyl polymer material having particles of a tear promoting agent dispersed therein, wherein the particles of the tear promoting agent have a melting temperature above the melting temperature of the vinyl polymer material, wherein the tear promoting agent is contained in the sheet of plasticized thermoplastic vinyl polymer material in an amount of at least 0.1 wt. % and of maximum 4.0 wt. % such that the sheet of plasticized thermoplastic vinyl polymer material has an elongation at break of between 200.0% and 400.0% at room temperature measured according to ISO 527 part 1 and 2 test piece 5A, and a trouser tear strength of maximum 25 N/mm measured according to ISO 34-1 Method A, wherein an aspect ratio of the largest dimension of the particles of the tear promoting agent with respect to the smallest dimension of the particles is at least 5.