Silicone-coated release film with a special vacuum deep drawing capability

Patent metadata

Field	Value
Publication number	US-10100165-B2
Application number	US-201414767127-A
Country	US
Kind code	B2
Filing date	Feb 11, 2014
Priority date	Feb 12, 2013
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

Siliconized release film for the production of polymer moldings from fiber composites using a mold, which comprises a support film which is capable of vacuum deep drawing at room temperature and a coating which can be applied in liquid form and consists, optionally after removal of any solvent, of more than 90 atom % of silicon, carbon and/or oxygen, more than 45 atom % of carbon and more than 20 atom % of silicon, in each case based on the total coating and measured by XPS, characterized in that the coating has been crosslinked by means of condensation reactions, addition reactions or radiation.

First claim

The invention claimed is:

1. A siliconized release film for use in the production of a polymer molding using a mold comprising
a support film being capable of vacuum deep drawing at room temperature;
wherein the support film has an elongation at break in accordance with DIN EN ISO 527, longitudinally and transversely, of from 100% to 2000%; and
a coating which is applied in liquid form on the support film and consists, optionally after removal of any solvent, of more than 90 atom % of silicon, carbon and/or oxygen, more than 45 atom % of carbon, and more than 20 atom % of silicon, in each case based on the total coating and measured by XPS;
wherein the coating has been crosslinked by means of condensation reactions or addition reactions;
wherein the polymer molding comprises a fiber composite; and
wherein the siliconized release film is flexible and can fit fine contours of a mold.

2. The release film as claimed in claim 1 , wherein the support film has a stress at 50% elongation in accordance with DIN EN ISO 527 of from 1 to 40 MPa.

3. The release film as claimed in claim 1 , wherein the support film has a softening range from 100 to 450° C.

4. The release film as claimed in claim 1 , wherein the crosslinked coating contains not more than 5% by weight of extractable constituents.

5. The release film as claimed in claim 1 , wherein the support film consists of thermoplastic polyester elastomers (TPE-E), thermoplastic copolyesters (TPC), crosslinked thermoplastic elastomers based on olefin (TPE-V/TPV); thermoplastic elastomers based on urethane (TPE-U/TPU), thermoplastic copolyamides (TPE-A/TPA) and/or mixtures of ethylene-vinyl acetate and polyvinylidene chloride (EVA/PVDC).

6. The release film as claimed in claim 1 , wherein the support film has a breaking stress in accordance with DIN EN ISO 527, longitudinally and transversely, of from 10 to 150 MPa.

7. The release film as claimed in claim 1 , wherein the support film has a tear propagation resistance in accordance with DIN ISO 34-1, B, longitudinally and transversely, of from 30 to 500 kN/m.

8. The release film as claimed in claim 1 , wherein the support film has a film thickness of from 8 μm to 250 μm.

9. The release film as claimed in claim 1 , wherein the support film is present in a deep-drawn state.

10. An arrangement made up of a mold for molding a polymer workpiece and a release film as claimed in claim 1 deep-drawn therein.

11. A process for producing a release film as claimed in claim 1 by coating a support film which is capable of being deep-drawn at room temperature, which comprises or consists of activating the film by treatment with wet-chemical primers, corona, DBD, low-pressure plasma, atmospheric pressure plasma and/or vacuum-UV radiation in a first step, applying a reactive silicone mixture by doctor blade coating or rolling in a second step, where the weight per unit area is from 2 to 50 g/m 2 , and crosslinking the reactive silicone mixture in a third step.

12. A process for using the release film according to claim 1 comprising using the release film as a demolding aid in the production of polymer moldings composed of fiber composite materials.

13. A process for using the release film according to claim 1 comprising using the release film as a protective film for polymer moldings composed of fiber composite materials.

14. A protective layer system for use with a mold comprising:
a release film comprising:
a support film being capable of vacuum deep drawing at room temperature;
wherein the support film has an elongation at break in accordance with DIN EN ISO 527, longitudinally and transversely, of from 100% to 2000%; and
a coating which is applied in liquid form on the support film and consists, optionally after removal of any solvent, of more than 90 atom % of silicon, carbon and/or oxygen, more than 45 atom % of carbon, and more than 20 atom % of silicon, in each case based on the total coating and measured by XPS;
wherein the coating has been crosslinked by means of condensation reactions, addition reactions or radiation; and

a molding component comprising a polymer fiber composite;
wherein the release film with the coating facing the molding component is disposed on and remains as surface protection on the molding component until removed as required with the coating remaining on the support film.

15. The protective layer system according to claim 14 , wherein the support film has a stress at 50% elongation in accordance with DIN EN ISO 527 of from 1 to 40 MPa.

16. The protective layer system according to claim 14 , wherein the support film has a softening range from 100 to 450° C.

17. The protective layer system according to claim 14 , wherein the coating has been cross linked by means of radiation.

18. The protective layer system according to claim 14 , wherein the crosslinked coating contains not more than 5% by weight of extractable constituents.

19. The protective layer system according to claim 14 , wherein the support film consists of thermoplastic polyester elastomers (TPE-E), thermoplastic copolyesters (TPC), crosslinked thermoplastic elastomers based on olefin (TPE-V/TPV); thermoplastic elastomers based on urethane (TPE-U/TPU), thermoplastic copolyamides (TPE-A/TPA) and/or mixtures of ethylene-vinyl acetate and polyvinylidene chloride (EVA/PVDC).

20. The protective layer system according to claim 14 , wherein the support film has a breaking stress in accordance with DIN EN ISO 527, longitudinally and transversely, of from 10 to 150 MPa.

21. The protective layer system according to claim 14 , wherein the support film has a tear propagation resistance in accordance with DIN ISO 34-1, B, longitudinally and transversely, of from 30 to 500 kN/m.

22. The protective layer system according to claim 14 , wherein the support film has a film thickness of from 8 μm to 250 μm.

23. The protective layer system according to claim 14 , wherein the support film is present in a deep-drawn state.

24. A process for producing the protective layer system according to claim 14 , comprising:
activating the support film with a treatment selected from the group consisting of a wet-chemical primer treatment, a corona treatment, a DBD treatment, a low-pressure plasma treatment, an atmospheric pressure plasma treatment, a vacuum-UV radiation treatment, and a combination of at least two of the aforementioned treatments;
after the activating step, applying a reactive silicone mixture to the support film by a doctor blade coating process or a rolling process;
wherein the weight per unit area of the reactive silicone mixture applied to the support film is in an amount from 2 to 50 g/m 2 ; and
crosslinking the reactive silicone mixture, thereby coating the support film.

25. A process for using the protective layer system according to claim 14 , comprising using the release film as a demolding aid in a production of polymer moldings composed of fiber composite materials.

26. A process for using the protective layer system according to claim 14 , comprising using the release film as a protective film for polymer moldings composed of fiber composite materials.

Assignees

• Fraunhofer Ges Forschung
• Fraunhofer Ges Z Foerderung Der Angewandten Forschung E V

Inventors

• Wilken Ralph
• Ott Matthias
• Vissing Klaus-Dieter
• Grassl Gregor

Classifications

• C09J2477/005

  in the release coating · CPC title

• C09J2427/005

  in the release coating · CPC title

• C08G77/12

  containing silicon bound to hydrogen · CPC title

• C08J7/12

  Chemical modification · CPC title

• C09J2483/005

  in the release coating · CPC title