Assembly with temporary protective film

Abstract

The invention relates to a composite comprising (i) a plastics component or (ii) a semifinished plastics product with a protective layer system, where the protective layer system comprises a plastics film and an organosilicon plasma polymer layer, the organosilicon plasma polymer layer is arranged between the (i) plastics component or the (ii) semifinished plastics product and the plastics film and, after the hardening of the (i) plastics component or of the (ii) semifinished plastics product, the organosilicon plasma polymer layer adheres more securely to the plastics film than to the (i) plastics component or the (ii) semifinished plastics product.

Claims

1. An assembly comprising: a mold; and (i) a plastic component or (ii) a semi-finished plastic product, each of (i) the plastic component or (ii) the semi-finished plastic product having a protective layer system disposed between the mold and (i) the plastic component or (ii) the semi-finished plastic product; wherein the protective layer system comprises a plastic film and an organosilicon plasma polymer layer, the plastic film being arranged between the mold and the organosilicon plasma polymer layer and the organosilicon plasma polymer layer being arranged between the plastic film and (i) the plastic component or (ii) the semi-finished plastic product and the plastic film; wherein after hardening of (i) the plastic component or of (ii) the semi-finished plastic product, the organosilicon plasma polymer layer adheres more securely to the plastic film than to (i) the plastic component or (ii) the semi-finished plastic product; wherein the plastic film comprises a material selected from the group consisting of a thermoplastic elastomer and a thermoplastic polymer; wherein the atomic ratios in the organosilicon plasma polymer layer as measured by means of XPS are: TABLE-US-00007 1.00 n(O + N):n(Si) 2.20, 1.20 n(C):n(Si) 2.00, 0.70 n(C):n(O + N) 2.00; and wherein the plastic film of the protective layer system is adapted for exerting a release effect in relation to the mold such that (i) the plastic component or (ii) the semi-finished plastic product having the protective layer system can be removed from the mold and subsequently the protective layer system can be peeled from (i) the plastic component or (ii) the semi-finished plastic product after the hardening of (i) the plastic component or (ii) the semi-finished plastic product.

2. The assembly according to claim 1, wherein based on the entirety of the elements silicon, oxygen, nitrogen, and carbon as 100 atom %, the following applies to values measured by means of XPS on the organosilicon plasma polymer layer: TABLE-US-00008 silicon from 17 to 27 atom %, (oxygen + nitrogen) from 26 to 50 atom %, carbon from 25 to 50 atom %.

3. The assembly according to claim 1, wherein a thickness of the organosilicon plasma polymer layer is 2 m or less.

4. The assembly according to claim 1, wherein a portion of (i) the plastic component or (ii) the semi-finished plastic product disposed on a side directed toward the organosilicon plasma polymer layer is entirely composed of a material selected from the group consisting of a thermoset, a thermoplastic, a matrix resin for a fiber-composite plastic, a plastic foam, and a lacquer.

5. The assembly according to claim 4, wherein the matrix resin for the fiber-composite plastic is a matrix resin selected from the group consisting of an epoxy resin, an polyurethane resin, a polyester resin, a vinyl ester resin, and a phenolic resin.

6. The assembly according to claim 4, wherein the lacquer is applied in an application selected from the group consisting of a gel coat and an adhesive.

7. The assembly according to claim 1, comprising: the plastic component; wherein the plastic component has been produced by a process selected from the group consisting of an injection molding, a reaction injection molding process, a foaming process, a fiber-composite material production process, an infusion process, a vacuum infusion process, a lamination process, a manual lamination process, an injection process, a resin transfer molding process, a liquid resin press molding process, a pray layup process, a prepreg process, and an in-mold-coating process.

8. The assembly according to claim 7, wherein the fiber-composite material production process is based on fibers selected from the group consisting of carbon fibers, glass fibers, and polymer fibers.

9. The assembly according to claim 1, wherein the softening point of the plastic film is 100 C. or greater.

10. The assembly according to claim 1, comprising the semi-finished plastic product being in a state which is not yet entirely hardened.

11. The assembly according to claim 10, wherein (i) the plastic component or (ii) the semi-finished plastic product is a web product.

12. The assembly according to claim 11, wherein the web product is a windable web product.

13. The assembly according to claim 1, wherein a material of (i) the plastic component or (ii) the semi-finished plastic product comprises a fiber-composite material.

14. The assembly according to claim 1 further comprising a layer of a coating material adjacent to the organosilicon plasma polymer layer and directed toward (i) the plastic component or (ii) the semi-finished plastic product.

15. The assembly according to claim 1, wherein based on the entirety of the elements silicon, oxygen, nitrogen, and carbon as 100 atom %, the following applies to values measured by means of XPS on the organosilicon plasma polymer layer: TABLE-US-00009 silicon from 17 to 27 atom %, (oxygen + nitrogen) from 26 to 50 atom %, carbon from 25 to 50 atom %; and and wherein: the thickness of the organosilicon plasma polymer layer is 2 m or less; the plastic film is composed of: a thermoplastic elastomer selected from the group consisting of a thermoplastic polyester elastomer (TPE-E), a thermoplastic copolyester (TPC), a polyetherester, a crosslinked thermoplastic elastomer based on olefins (TPE-V/TPV), a mixture of polypropylene and ethylene-propylene-diene rubber (EPDM/PP), a thermoplastic elastomer based on urethanes (TPE-U/TPU), a mixture of natural rubber and polypropylene (NR/PP), a mixture of nitrile rubber and polypropylene (NBR/PP), and a mixture of ethylene-vinyl acetate and polyvinylidene chloride (EVA/PVDC), or a thermoplastic polymer selected from the group consisting of a polyolefin, a polymethylpentene (PMP), a polyolefin copolymer, a polyamide, a nylon-6,6, a poly--caprolactam, a polyethylene terephthalate (PET), and a polyimide (PI); a portion of (i) the plastic component or (ii) the semi-finished plastic product disposed on a side directed toward the organosilicon plasma polymer layer is entirely composed of a material selected from the group consisting of a thermoset, a thermoplastic, a matrix resin for fiber-composite plastics, a plastic foam, and a lacquer; the plastic component has been produced by a process selected from the group consisting of an injection molding, a reaction injection molding, a foaming process, a fiber-composite material production process, an infusion process, a vacuum infusion process, a lamination process, a manual lamination process, an injection process, a resin transfer molding process, a liquid resin press molding process, a pray layup process, a prepreg process, and an in-mold-coating process; the softening point of the plastic film is 100 C. or greater; the material for the plastic component or the semi-finished plastic product comprises a fiber-composite material; and the assembly further comprises a layer of a coating material adjacent to the organosilicon plasma polymer layer and directed toward the (i) plastic component or (ii) semi-finished plastic product.

16. The assembly according to claim 15, wherein based on the entirety of the elements silicon, oxygen, nitrogen, and carbon as 100 atom %, the following applies to values measured by means of XPS on the organosilicon plasma polymer layer: TABLE-US-00010 silicon from 19 to 26 atom %, oxygen from 30 to 45 atom %, carbon from 33 to 48 atom %.

17. The assembly according to claim 1, wherein the atomic ratios in the organosilicon plasma polymer layer, measured by means of XPS, are: TABLE-US-00011 1.25 n(O):n(Si) 2.10, 1.60 n(C):n(Si) 2.00, 0.80 n(C):n(O) 1.80.

18. The assembly according to claim 1, wherein based on the entirety of the elements silicon, oxygen, nitrogen, and carbon as 100 atom %, the following applies to values measured by means of XPS on the organosilicon plasma polymer layer: TABLE-US-00012 silicon from 19 to 26 atom %, oxygen from 30 to 45 atom %, carbon from 33 to 48 atom %.

19. The assembly according to claim 1, wherein the plastic film is composed of a thermoplastic elastomer is selected from the group consisting of a thermoplastic polyester elastomer (TPE-E), a thermoplastic copolyester (TPC), a polyetherester, a crosslinked thermoplastic elastomer based on olefins (TPE-V/TPV), a mixture of polypropylene and ethylene-propylene-diene rubber (EPDM/PP), a thermoplastic elastomer based on urethanes (TPE-U/TPU), a mixture of natural rubber and polypropylene (NR/PP), a mixture of nitrile rubber and polypropylene (NBR/PP), and a mixture of ethylene-vinyl acetate and polyvinylidene chloride (EVA/PVDC).

20. The assembly according to claim 1, wherein the plastic film is composed of a thermoplastic polymer selected from the group consisting of a polyolefin, a polymethylpentene (PMP), a polyolefin copolymer, a polyamide, a nylon-6,6, a poly--caprolactam, a polyethylene terephthalate (PET), and a polyimide (PI).

21. An assembly comprising: a mold; and (i) a plastic component or (ii) a semi-finished plastic product, each of (i) the plastic component or (ii) the semi-finished plastic product having a protective layer system disposed between the mold and (i) the plastic component or (ii) the semi-finished plastic product; wherein the protective layer system comprises a plastic film and an organosilicon plasma polymer layer, the plastic film being arranged between the mold and the organosilicon plasma polymer layer and the organosilicon plasma polymer layer being arranged between the plastic film and (i) the plastic component or (ii) the semi-finished plastic product and the plastic film; wherein after hardening of (i) the plastic component or of (ii) the semi-finished plastic product, the organosilicon plasma polymer layer adheres more securely to the plastic film than to (i) the plastic component or (ii) the semi-finished plastic product; wherein the plastic film comprises a material selected from the group consisting of a thermoplastic elastomer and a thermoplastic polymer; wherein the atomic ratios in the organosilicon plasma polymer layer as measured by means of XPS are: TABLE-US-00013 1.00 n(O + N):n(Si) 2.20, 1.20 n(C):n(Si) 2.00, 0.70 n(C):n(O + N) 2.00; and wherein the plastic film of the protective layer system is adapted for exerting a release effect in relation to the mold such that (i) the plastic component or (ii) the semi-finished plastic product having the protective layer system can be removed from the mold and subsequently the protective layer system can be peeled from (i) the plastic component or (ii) the semi-finished plastic product after the hardening of (i) the plastic component or (ii) the semi-finished plastic product; wherein the plastic component has been produced by a process selected from the group consisting of an injection molding, a reaction injection molding process, a foaming process, a fiber-composite material production process, an infusion process, a vacuum infusion process, a lamination process, a manual lamination process, an injection process, a resin transfer molding process, a liquid resin press molding process, a pray layup process, a prepreg process, and an in-mold-coating process; wherein (i) the plastic component has been produced by the lamination process and (i) the plastic component or (ii) the semi-finished plastic product further comprises a material selected from the group consisting of a wood, a metal and a combination thereof.

Description

EXAMPLES

Example 1

(1) Production of Protective Layer Systems to be Used in the Invention

(2) The (temporary) protective layer system to be used in the invention was produced by providing a plasma polymer coating in a 3 m.sup.3 plasma reactor to Walopur 2102 AK 050 thermoplastic polyurethane film from Epurex Films. The film here, width 1600 mm and thickness 50 m, was passed at a distance of about 40 mm in front of two cooled electroplates each of which measured 500 mm (along the direction of the web)2300 mm. The plasma process parameters set during the coating process were as follows:

(3) TABLE-US-00005 TABLE 1 Process parameters Coating 1 Coating 2 Coating 3 Flow rate of O.sub.2 gas (Sccm): 250 350 450 Flow rate of HMDSO (Sccm): 250 175 150 Power (W): 4500 4500 5500 Web velocity (m/min) 2.5 2.5 2.5 Pressure (mbar): 0.021 0.02 0.025

(4) Before the process was carried out it was ensured that the rate of leakage (external leaks) of the vacuum chamber used was markedly less than 210.sup.1 mbar L/s. The operating frequency was 13.56 MHz.

Example 2

(5) XPS Measurements

(6) XPS measurements (ESCA measurements) were made with an Escalab spectrometer from VG. The measurement equipment was calibrated in such a way that the aliphatic Anteil C 1s peak is at 285.00 eV. Because of charge effects it was necessary to shift the energy axis to this fixed value, with no further modification. The analysis chamber was provided with an X-ray source for monochromatic Al K radiation, an electron source as neutralizer, and a quadrupole mass spectrometer. The system also had a magnetic lens which focused the photoelectrons through an entrance slit into a hemispherical analyzer. During measurement the normal to the surface was directed toward the entrance slit of the hemispherical analyzer. The pass energy during determination of the atomic ratios was always 80 eV. During determination of the peak parameters the pass energy was always 20 eV.

(7) It was found that, within the bounds of measurement tolerances, the measurement results could be regarded as identical irrespective of whether the coating was measured on the temporary protective film or on silicon wafers as reference material. The results on wafers are shown here:

(8) TABLE-US-00006 TABLE 2 Results of XPS measurements O C Si N (at %) (at %) (at %) (at %) O/Si C/Si C/O Coating 1 32.1 44.6 23.3 0 1.38 1.91 1.39 Coating 2 40.8 37.6 21.4 0.2 1.91 1.76 0.92 Coating 3 41.2 37.8 20.8 0.2 1.98 1.82 0.92

Example 3

(9) Formability

(10) Formability was determined by subjecting film sections from Example 1 to a forming process in an open mold at room temperature with vacuum support up to a tensile strain value of 250%, and then applying gel coat from Bergolin with the following composition, and hardening for about 3 hours at room temperature: Steodur PUR GELCOAT Handmasse 6D970-5015-1; 50 g Steodur PUR HARDNER 7D202; 30 g Steodur PUR Beschleuniger Blau 6D972-0000; 1.5 ml

(11) The film sections with the three coatings could then be peeled without difficulty. This was true even for the regions with 250% tensile strain.

Example 4

(12) Adhesion

(13) Bond strengths were moreover estimated by using the two-component epoxy adhesive 2011 Araldite 2000+ from Huntsman to bond the coated films from Example 3 to a glass microscope slide (adhesive joint: 1 mm). After four days of hardening at room temperature, a lateral incision was made in a film strip of width 20 mm, and a spring balance was used to peel the material at a velocity of about 120 cm/min at an angle of 180. The forces required for this were:

(14) Coating 1: about 0.09 N

(15) Coating 2: about 0.14 N

(16) Coating 3: about 0.12 N

(17) As comparison, the same polymer film was also equipped with a coating as in DE 10 2006 018 491 A1. Peeling of the film here required a force of only 0.02 N, whereas the force required for the uncoated film was more than 10 N, and the peeling process here also caused severe plastic deformation of the film.

(18) Bond strengths in relation to an epoxy resin (Cycom 977-2) were estimated by hardening sample sheets made of four layers of the woven-fabric prepreg 977-2A-35-6KHTA-5H-370-T2 from Cytec on the coated film from Example 3 in an autoclave at 180 C. under a gauge pressure of 8 bar. The heating and cooling rates selected for this were respectively 4 K/min and 5 K/min. Between heating and cooling, the temperature was kept at 180 C. for two hours. After cooling to room temperature, a lateral incision was made in a film strip of width 25 mm, and the material was peeled at a velocity of about 120 cm/min in and, respectively, perpendicularly to the direction of the fibers. The forces required for this were as follows:

(19) Coating 1: about 0.03 N

(20) Coating 2: about 0.13 N

(21) Coating 3: about 0.45 N

(22) As comparison, the same polymer film was also equipped with a coating as in DE 10 2006 018 491 A1. The force required here to peel the film was only 0.01 N, whereas the uncoated film could not be peeled from the hardened prepreg sheets, but instead tore.

(23) The adhesion on the polymer film with the coating of the invention on the molding is on the one hand sufficiently small that the film can be peeled from the cured molding without difficulty (in particular without tears in the polymer film). On the other hand, the adhesion of the film is sufficiently good to provide effective protection of the molding, and to permit storage or transport thereof, or even mechanical operations thereon, with the protective film of the invention.

(24) In the embodiment of the invention in which external areas of semifinished products are equipped with the release film for the manufacture of fiber-composite components (in particular prepregs), an additional handling cost is moreover saved by laying a release film in/on the mold before the prepreg layers, or the surface master, are/is assembled. This is possible because of the adhesion values in the layer composite.

Example 5

(25) Glassfiber-Composite Component (Rotor Blade) Produced by Infusion Technology Inclusive of in-Mold Coating

(26) Before manufacture of an external GRP skin of a rotor blade for wind turbines with the aid of infusion technology, a TPU film of thickness 40 m in the form of web product, which had been equipped in advance in a low-pressure plasma process on the side facing away from the mold with 20 nm of Coating 2 from Example 1 was placed across the mold, instead of a liquid release agent. Said film is then inserted into the mold by a forming process, and a gel coat based on polyurethane is applied as outer coating material. Directly after application, the outer coating material is predried to a small extent by IR driers, and the laid glassfiber scrim, and also the other manufacturing elements, are placed thereon. Once the usual vacuum has been applied, the fiber material is evacuated, and the epoxy-based matrix resin is injected. The GRP component is then hardened in the usual way by heating, and then removed from the mold with the TPU film. The film remains very substantially as surface protection on the outer coating material until transport to the wind turbine has been completed. Prior to assembly, the film is peeled (e.g. manually). Coating 2 from Example 1 remains entirely on the film here. The surface structure of the matt TPU film provides a matt surface on the hardened external skin of the rotor blade.

Example 6

(27) Filament Winding

(28) Filament winding is used to mold carbon fibers, which during the winding procedure are wetted with an epoxy-based matrix resin, and are then hardened in an autoclave. For demolding without use of release agent, a plastic tube of thickness 60 m made of TPC and previously provided externally with Coating 3 from Example 1 in a low-pressure web-product plasma process is drawn onto the core before the winding process. After the winding process, a TPC tube of thickness 60 m which had previously been provided externally with Coating 3 from Example 1 in a low-pressure web-product plasma process was drawn externally over the fibers. The external side of this tube is, however, turned toward the inside. This second tube has regular holes through which excess resin material can escape during the hardening process. After the usual hardening process, the tubes initially still remain as surface protection on the CFC component, and are withdrawn manually only when necessary. All of the Coating 3 here remains on the TPC film. The CFC surface is clean and free from release agents, and can therefore by way of example be coated without difficulty.

Example 7

(29) Carbon-Fiber Composite Component Produced by Prepreg Technology

(30) With use of prepreg technology, preimpregnated carbon fibers which, after production thereof, have been wetted with an epoxy-based matrix resin are placed manually (manual lamination) or by machine (e.g. tape laying, fiber placement) onto or into a mold with release film to be used in the invention (polymer film, protective film), and are then hardened in an autoclave. These preimpregnated semifinished products have to be stored under cold conditions (generally <-18 C.) in order to suppress premature hardening of the matrix resin. For demolding without use of additional external or internal release agents, a 60 m TPU film which has previously, in the form of web product, been equipped with 50 nm of Coating 2 from Example 1 in a low-pressure plasma process on the side facing away from the mold is drawn into the mold by a forming process so that it is in crease-free contact with the mold surface. The subsequent placing of the prepreg layers takes place in a manner such that the first layer is placed on the coated protective film previously drawn into the mold (temporary) peripheral fixing of the protective film. A procedure that has proven to be helpful here is, in particular during the placing of the first 1-2 prepreg layers. Once the final prepreg layer has been placed, the usual vacuum is applied, and the usual hardening process takes place in the autoclave. After demolding, the TPU film initially still remains as surface protection on the CFC component, and is peeled only when necessary. All of Coating 2 here remains on the TPU film. The CFC surface is clean and free from release agents, and can therefore by way of example be coated without difficulty.

Example 8

(31) Preimpregnated Semifinished Products for the Manufacture of Fiber-Composite Components

Semifinished Products for Lightning Protection

(32) For the manufacture of a fiber-composite external-skin component using preimpregnated semifinished products for lightning protection (copper mesh), the copper mesh preimpregnated with an epoxy resin is wound onto a roll with a TPU film of thickness 60 m which in the form of web product had previously been provided on the side facing toward the preimpregnated copper mesh with 60 nm of Coating 2 from Example 1 in a low-pressure plasma process. Said preimpregnated copper mesh is then, with the film, placed into the mold by hand or by machine. Any required overlap of adjacent webs (to ensure conduction of electrical current) is ensured in that either the film in the overlapping marginal region on the upper web is peeled directly before insertion, or said marginal region is not provided with said film. The usual plurality of prepreg layers are then placed on the semifinished product for lightning protection. After the usual autoclave hardening process, the fiber-composite external skin inclusive of the temporary protective film is cleanly demolded from the mold. The temporary protective film initially still remains as surface protection on the CFC component, and is peeled only when necessary.

Example 9

(33) Preimpregnated Semifinished Products for the Manufacture of Fiber-Composite Components: Laid Fiber Scrims

(34) A fiber-composite component is manufactured by winding unidirectional epoxy-resin prepreg onto a roll with a TPU film of thickness 60 m which had previously, in the form of web product, been provided on the side facing toward the prepreg with 30 nm of Coating 2 from Example 1 in a low-pressure plasma process. This prepreg is then placed by machine edge-to-edge as first layer with the film into a mold. Further layers of prepreg without the film are then placed as usual on this first layer. After the usual autoclave hardening process, the fiber-composite external skin inclusive of the temporary protective film is cleanly demolded from the mold. The temporary protective film initially still remains as surface protection on the CFC component, and is peeled only when necessary.

Example 10

(35) Coated Fiber-Composite Component Produced by Prepreg Technology

(36) A coated fiber-composite component is manufactured by using, in the production of the prepreg material, not only the protective film (coated polymer film) to be used in the invention but also a film of coating material (preferably in the form of formable film material) that has not been entirely hardened, arranged between the film and a unidirectional phenolic resin prepreg material. This prepreg structure permits introduction of roll product or panel product into a heated forming mold in which the composite is converted to the final form and hardened.

(37) The temporary protective film protects the surface of the coating during processing and optionally during further processing and/or transport of the component. It moreover ensures that forming molds are clean (without accumulation of release agent), and that a uniform surface of the coating material is obtained by a solvent-free manufacturing process. This is a general feature when the composite of the invention is used in combination with a coating material.

(38) The prepreg material is produced by using a TPU film of thickness 80 m which, in the form of web product, had previously been provided on the side facing toward the prepreg with a Coating 2 of thickness 50 nm from Example 1 in a low-pressure plasma process. The film of other coating material is applied to said coating. The preimpregnated fiber material is applied to the film of coating material. It is possible here not only to apply unidirectional layers or woven fabrics but also to apply short-fiber material for the production of (quasi-)isotropic fiber-reinforced plastics for example via spraying. The resultant surface is generally protectively covered by a release film or a release paper. If the fiber-composite component to be manufactured is to be manufactured with only one layer of said semifinished product comprising coating material, a further layer of the coated TPU film described above can be used.

(39) After the forming process and hardening process, the TPU film can initially remain as surface protection on the fiber-composite component, and is peeled only when necessary. All of the Coating 2 here remains on the TPU film here. Hardening of the film of coating material and the prepreg material together in the heated forming mold produces a composite with firm adhesion. The extensible protective film is effective in suppressing defects produced by the forming process in the surface of the coating material, and equally traditional coating defects due to dust or to emission of gas from the fiber material.