KR20050045565A - Weatherproof laminated film for automobile decoration - Google Patents

Abstract

The present invention relates to a laminated film for automobile decoration excellent in weather resistance, the film preferably comprises a protective masking film from above, a transparent coat layer, a color coat layer, a pressure-sensitive adhesive layer and a release backing layer, the transparent coat in the structure The layer is a multilayer structure having a different composition of the first layer and the second layer, and the first layer contains 50 to 95% by weight of polyvinylidene fluorine resin and 5 to 50% by weight of polymethyl methacrylate resin. The layer contains 5 to 50 weight percent polyvinylidene fluorine resin, 50 to 95 weight percent polymethyl methacrylate resin and 0.1 to 15 weight percent UV stabilizer. In particular, the layer containing a lot of polyvinylidene fluorine resin is excellent in weather resistance to act as a protective layer, the layer containing a lot of polymethyl methacrylate resin is easy to color coating because it has good adhesion to the other side. The multilayered film has excellent adhesion durability after being laminated with an adhesive on a substrate, and also has excellent chemical resistance, weather resistance, scratch resistance, and glossiness, and thus is suitable for interior and exterior decorative films.

Description

Weatherproof laminated film for automobile decoration

The present invention relates to a vehicle decorative film including a fluororesin of a multi-layer structure. Since the film has excellent chemical resistance, weather resistance, scratch resistance and glossiness, it is suitable for use in decorative film applications.

Background Art A process of painting a vehicle body in a conventional automobile exterior has been generally used. The painting process usually repeats painting and drying three times, so the time, facility and cost account for 1/4 to 1/3 of the total automobile production. In addition, environmental equipment such as dust collecting equipment for removing volatile organic compounds (VOC) discharged from the paint is required, and additional costs are incurred to process the thermosetting hard coating upon recycling.

In order to overcome the problems of the painting process, a method of attaching a film to the outside of the vehicle body has been attempted. Initially, films using plasticized polyvinyl chloride (PVC) were developed. However, as environmental regulations on the use of PVC have been strengthened, films using polyvinylidene fluoride resin having excellent weatherability and elongation while replacing PVC have been developed.

US Pat. No. 5,518,786 and US Pat. No. 60,963,96 are examples of exterior films using polyvinylidene fluorine resin, the biggest difference being in the treatment of the transparent coat layer and the color coat layer. In US Pat. No. 5,518,786, an adhesive is used to connect the transparent coat layer and the collar coat layer. In US Patent 6096396, the composition of the transparent coat layer and the color coat layer is similar to allow coating with each other without using an adhesive. Although the process has been improved by reducing the adhesion step, the inclusion of more fluorine resin in the color coat layer than acryl in order to match the composition results in poor adhesion with the pigment and insufficient dispersion of the UV stabilizer resulting in evaporation or dissipation. .

Therefore, it is difficult to improve both the bonding of the transparent coat layer and the color coat layer, the adhesiveness with the pigment, and the dispersion of the UV stabilizer in the film containing the fluorine resin of the conventional single layer structure.

The present inventors solved the above problem by making the structure of the film containing a fluororesin into a multilayer. That is, the transparent coating layer film is manufactured by coextrusion by changing the composition of the fluorine resin and the acrylic resin in the first layer and the second layer of the transparent film. When ink printing is performed on the second layer of the transparent film, a color coat layer is realized, so that a process of connecting the transparent coat layer and the color coat layer with an adhesive is not necessary, and when manufacturing a multi-layer film by coextrusion. Since the composition of the fluororesin and the acrylic resin in the second layer can be different from that of the first layer, it was confirmed that an appropriate ratio can be selected in consideration of the adhesiveness with the pigment and the dispersion property of the UV stabilizer.

Accordingly, an object of the present invention is to improve the adhesion of pigments and insufficient dispersion of UV stabilizers, which is a problem of films containing fluororesins with a single layer structure, and does not require an adhesion process between the transparent coat layer and the color coat layer. It is to provide a laminated film for automobile decoration of high weather resistance.

In order to achieve the above object, the present invention is a weatherproof laminated film that can be used for automotive interior and exterior decoration, at least includes a transparent coat layer and a color coat layer, the transparent coat layer comprises a fluorine resin and an acrylic resin 2 It has a multilayer structure of more than one layer, and the composition ratio of fluorine resin and acrylic resin in each layer of the transparent coat layer of the multilayer structure is different from each other, but in the transparent coat layer adjacent to the color coat layer, the acrylic resin content is the same or higher than that of the fluorine resin. It provides a weather-resistant laminated film for automobile decoration, characterized in that.

In the present invention, the transparent coat layer has at least a two-layer structure, the first layer includes a fluororesin and an acrylic resin, and the second layer includes a fluororesin, an acrylic resin, and a UV stabilizer. The fluorine resin used for the transparent coat layer contains polyvinylidene fluoride, and the acrylic resin contains polymethyl methacrylate. Preferably, the transparent coat layer is prepared by coextrusion method. The total thickness of the transparent coat layer is 10 to 150㎛, wherein the thickness of the first layer is preferably 2 to 50㎛. The color coat layer may include an ink print layer and a base coat layer.

The weatherproof laminated film for automobile decoration of the present invention is preferably composed of a protective masking film, a transparent coat layer, a color coat layer, a pressure-sensitive adhesive layer and a release backing layer so as to be laminated on a substrate by an adhesive method. Polyethylene terephthalate or CPP (cast polypropylene) may be used as the protective masking film.

The transparent coat layer and the color coat layer preferably have sufficient weather resistance, heat resistance, chemical resistance, and glossiness for application to exterior decoration.

The invention can be explained in more detail with reference to the accompanying drawings.

1 is a cross-sectional view of a weatherproof laminated film for automobile decoration according to an embodiment of the present invention, wherein the laminated film is a transparent coat layer 4 and a transparent coat layer 4 laminated on a protective masking film 2 from above. ), A pressure-sensitive adhesive layer 8, a release backing layer 10, which is laminated on the color coat layer 6, the color coat layer 6, and detachably adhered to the release backing layer 10.

The protective masking film 2 should have sufficient heat resistance for the drying process in the lamination step, and an adhesive treatment is required on one side for bonding with the transparent coat layer 4. In addition, a high gloss surface is required to increase the glossiness when transitioned to the transparent coat layer 4. Suitable materials for this include PET (polyethylene terephthalate), CPP (cast polypropylene) and the like, and the preferred thickness of the protective masking film 2 is about 50 µm.

The transparent coat layer 4 is in the form of a film produced by coextrusion, and laminated on the protective masking film 2 through a lamination process. The layer is a multi-layered structure having different compositions of the first layer 4a and the second layer 4b, and the first layer 4a is 50 to 95 wt% polyvinylidene fluorine resin and 5 to 50 wt% poly Methyl methacrylate resin, the second layer (4b) is 5 to 50% by weight polyvinylidene fluorine resin, 50 to 95% by weight polymethyl methacrylate resin, 0.1 to 15% by weight UV stabilizer It contains. The composition of the first layer 4a and the second layer 4b can be changed depending on the application to which the product is applied. It should be noted that when the content of polyvinylidene fluorine resin is less than 50% by weight, the weather resistance is low and blocking may occur. When the content of the polyvinylidene fluorine resin is more than 95% by weight, peeling may occur due to poor adhesion to other surfaces. In addition, when the content of the polymethyl methacrylate resin is 50% by weight or less, the dispersion of the UV stabilizer is insufficient, so that evaporation or dissipation is likely to occur. Moreover, when it is 95 weight% or more, the adhesive force of the 1st layer 4a and the 2nd layer 4b falls.

If the film has a multilayer structure, all of the physical properties required by the color coat layer 6 and the transparent coat layer 4 can be satisfied. The layer containing a large amount of polyvinylidene fluorine resin acts as a protective layer because of its excellent weather resistance, and the layer containing a large amount of polymethyl methacrylate resin has good adhesion to adjacent surfaces without any surface treatment, so it is easy for color coating. Do. The total thickness of the transparent coat layer 4 is preferably 10 to 150 µm. In the case of the second layer 4b including the UV stabilizer, at least 20% of the total thickness may be sufficient to protect the substrate. Moreover, since the characteristic did not improve even if the thickness of the 1st layer 4b is 50 micrometers or more, 2-50 micrometers is suitable.

The color coat layer 6 is realized by performing ink printing on the transparent coat layer 4. It is coated on the second layer 4b of the transparent coat layer 4 by gravure printing or the like using the ink passed through the weather resistance, heat resistance and elongation test. By varying the pattern of the printing roll, a film having thousands of design patterns can be produced. Moreover, it can print by mixing ink binders, such as acrylic resin and urethane.

In order to make the printed pattern more clear, the base coat may be additionally coated. The ink used in the base coat should also have similar weather resistance and heat resistance as the ink used in the printing and should be composed of components that do not block. As for the thickness of the collar coat layer 6, 25-35 micrometers is preferable.

The pressure sensitive adhesive layer 8 is coated on the release backing layer 10 and then laminated on the color coat layer 6. Since the adhesive is applied to the exterior, it should be able to be thinly coated, and provide appropriate adhesion to both the substrate such as metal and the color coat layer 6, and should be easy to remove the adhesive remaining on the substrate when the film is peeled off.

When the laminated film of the present invention is applied to a substrate such as an automobile, the release backing layer 10, which is a release paper, is removed and then laminated by an adhesive method using the pressure-sensitive adhesive rather than thermoforming.

The use of the weatherproof laminated film according to the present invention is suitable for decoration, in particular for interior and exterior decoration of automobiles, the preferred use is to replace the paint coating of the car body, to give the same effect as the coating by attaching a film implementing ink printing instead of paint Used. In this case, it is preferable to use an adhesive that adheres well to the automobile body (steel), and the pressure-sensitive adhesive used here is, for example, acrylic resins such as ethyl acetate (EA), isopropyl alcohol (IPA), toluene (TOL), methyl It is prepared by coating the release backing layer with an adhesive liquid dissolved in a solvent mixed with ethyl ketone (MEK).

Example 1

The transparent coat layer is composed of two layers. The resins described below are mixed in proportion in a molten state using a twin screw extruder to obtain a mixture, and the mixture of each layer is prepared by co-extrusion using an extrusion T-die. . The mixing ratio was as follows and the total thickness was made to 50 μm.

The first layer contained 70 wt% of polyvinylidene fluoride and used "Kynar 720" from Atofina. The polymethyl methacrylate resin used 30 wt% of LG MMA "IG 840" and the thickness was 20 Prepared to μm.

The second layer contained 30 wt% polyvinylidene fluoride and used Atofina's "Kynar 720", 70 wt% polymethyl methacrylate resin used LG MMA's "IG 840", UV stable As a zero, 3 wt% of "Tinuvin P" of Ciba-Geigy was added. The thickness was made to 30 μm.

The color coat layer was prepared by printing the following ink coating liquid on the surface of the second layer of the transparent coat layer. The coating solution was 10 wt% of KYNAR 301F (Atofina), a polyvinyl fluoride resin, 16 wt% of CAP resin CAP-482-05 (Eastman), 3 wt% of MR-7HG (Soken), an anti-block agent. 3 RLTN (Ciba-Geigy), 2030 (Ciba-Geigy), Blue 8500 (Switzerland Chemical), M 380 (Toyo), 3 wt%, M 890 (Degussa) 2 wt%, isopropyl alcohol (IPA) 11 wt%, normal propyl alcohol (NPA) 17 wt%, ethyl acetate (EA) 17 wt%, propylene glycol methyl ether (PM) 12 wt%, ethyl cellosolve (EC) 3 wt%, toluene (TOL) 3 wt%, methyl ethyl ketone (MEK) 3 wt%.

Printing was coated on a clear coat layer using a gravure printing method.

The coating solution to be used as the base coat was prepared by changing the composition ratio of the pigment and the solvent in the coating solution. The base coat solution was coated on the printed surface of the color coat layer through gravure printing and then dried.

The pressure-sensitive adhesive layer was prepared by coating an adhesive resin obtained by dissolving an acrylic resin in a solvent mixed with ethyl acetate (EA), isopropyl alcohol (IPA), toluene (TOL), and methyl ethyl ketone (MEK) on a release backing layer.

Example 2

The laminated film prepared in Example 1 was found to be applicable to the exterior decoration through the following test.

The weather resistance of the film was measured using QUV, and the results are shown in Table 1 below.

division Early 250 hours change L * a * b * L * a * b * ΔE * Black 3.92 -0.14 -0.78 4.07 -0.12 -0.67 0.19 Red 31.18 51.09 48.24 31.17 51.05 48.25 0.05 Blue 12.67 4.25 -30.38 13.26 3.57 -29.96 0.99

After testing the QUV for 250 hours, the color change was measured using a color difference meter. As shown in Table 1, there was almost no color change of the color coat layer.

In addition, after testing for 2,500 hours in QUV, the adhesion between the transparent coat layer and the color coat layer was tested by the checker tape method (ASTM D 3359). As a result, all 100 cells were excellent in adhesive strength without the poor adhesion.

The present invention is to produce a transparent coat layer film by coextrusion by varying the composition of the fluorine resin and the acrylic resin in the structure of the transparent film containing a fluorine resin in a multi-layer, that is, the first layer and the second layer of the transparent film, When ink printing is performed on the second layer of the transparent film, a color coat layer is realized, so that a process of connecting the transparent coat layer and the color coat layer with an adhesive is not required. Since the composition of the fluorine resin and the acrylic resin can be different from that of the first layer in the second layer, an appropriate ratio can be selected in consideration of the adhesiveness with the pigment and the dispersion characteristics of the UV stabilizer.

In particular, the layer containing a lot of polyvinylidene fluorine resin is excellent in weather resistance to act as a protective layer, the layer containing a lot of polymethyl methacrylate resin is easy to color coating because it has good adhesion to the other side. The multilayered film has excellent adhesion durability after being laminated with an adhesive on a substrate, and also has excellent chemical resistance, weather resistance, scratch resistance, and glossiness, and thus is suitable for interior and exterior decorative films.

1 is a cross-sectional view of a weatherproof laminated film for automobile decoration according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

2: protective masking film

4: transparent coat layer

4a: first transparent coat layer

4b: second transparent coat layer

6: color coat layer

8: pressure-sensitive adhesive layer

10: release backing layer

Claims (9)

The first and second layers having different composition ratios of the fluororesin and the acrylic resin, wherein the interior and exterior decoration of the vehicle includes a transparent coating layer having a two-layer structure in which the acrylic resin content in the second layer is the same or higher than that of the fluororesin. In the weatherable laminated film that can be used as The laminated film is composed of a protective masking film, a transparent coat layer, a color coat layer, a pressure-sensitive adhesive layer and a release backing layer from above, and implements a color coat layer without adhesive by performing ink printing on the second layer of the transparent coat layer. Weatherproof laminated film for automobile decoration, characterized in that. The weatherproof laminated film for automobile decoration according to claim 1, wherein the second layer of the transparent coat layer comprises a fluororesin, an acrylic resin, and a UV stabilizer. The weatherproof laminated film for automobile decoration according to claim 1, wherein the fluororesin comprises polyvinylidene fluoride and the acrylic resin comprises polymethyl methacrylate. The weatherproof laminated film for automobile decoration according to claim 1, wherein the transparent coat layer is coextruded. The weatherproof laminated film for automobile decoration according to claim 1, wherein the total thickness of the transparent coat layer is 10 to 150 µm and the thickness of the first layer is 2 to 50 µm. 2. The weatherproof laminated film for automobile decoration according to claim 1, wherein the color coat layer further comprises an ink print layer and a base coat layer. The weatherproof laminated film for automobile decoration according to claim 1, wherein the protective masking film is polyethylene terephthalate or CPP (cast polypropylene). 8. The weatherproof laminated film for automobile decoration according to any one of claims 1 to 7, wherein the laminated film is used for paint coating of a vehicle body and laminated with a pressure-sensitive adhesive rather than thermoforming on the vehicle body. [Claim 9] The automobile of claim 8, wherein the pressure sensitive kneading agent is obtained by dissolving an acrylic resin in a solvent mixed with ethyl acetate (EA), isopropyl alcohol (IPA), toluene (TOL), and methyl ethyl ketone (MEK). Decorative weatherproof laminated film.