JP2000085075A - Coating substitution film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating substitution film for obtaining a colored injection molding for an exterior part of an automobile or the like having excellent appearance by using a composite film having a base layer composed of a specified composition. SOLUTION: A composite film is formed by sequentially laminating a transparent layer, a colored layer, an adhering layer and a base layer. The base layer, which is a component layer of a coating substitution film, is composed of a propylene/ethylene random copolymer (a), 10-300 pts.wt. low-density polyethylene or a linear low-density polyethylene to 100 pts.wt. of (a) (b), and 5-40 pts.wt. talc having an average particle diameter of 10 μm or lower to 100 pts.wt. of (a)+(b). The coating substitution film has good preforming characteristics for thermoforming, and has an excellent appearance after preforming, thereby it is preferably used for a molding for an exterior part of an automobile or the like such as a bumper, a side mold, a mud guard, a wheel cap, a spoiler or the like which requires designing characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint substitute film having excellent appearance after molding, and more particularly to a paint substitute film for forming a colored coating layer on the surface of a molded product produced by injection molding simultaneously with injection molding. It is about a film.

[0002]

2. Description of the Related Art Most of plastic automobile exterior parts such as bumpers and side moldings are formed by injection molding. However, in most cases, acrylic modified melamine or acrylic modified isocyanate is used from the viewpoint of design and scratch resistance. The coating is applied by a method of spray-coating a thermosetting resin paint of a system onto a molded article, followed by baking. In other words, after applying a paint through a multi-step process in a coating facility, the plastic injection molded product requires many steps of drying in a drying facility, so that painting is expensive. there were. In addition, there is also a problem that there is a concern about workplace environmental hygiene and environmental protection due to volatile organic solvent emission during drying.

[0003] In recent years, studies have been made to solve or alleviate such a problem.
According to Japanese Patent No. 3077, after a composite sheet composed of a transparent layer, a colored layer, and a backup sheet (base layer) is preformed, this is inserted in a mold in advance, and synthetic resin is injection-molded and integrated. A method for obtaining a molded article provided with a colored coating layer has been proposed.

In recent years, polyolefins have been developed for automobile parts, and accordingly, there have been many demands for composite sheets as described above, which use a polyolefin resin for the base material layer. Various sheets are being considered. However, the appearance of these composite sheets is likely to be deteriorated due to the occurrence of surface unevenness called a shark soldering phenomenon at the stage of the heat treatment in the preforming, and this phenomenon does not disappear even after injection molding, and as a result, the image becomes clear. There was a problem that it was not possible to obtain a highly molded product.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a coating substitute film for improving the above-mentioned drawbacks and obtaining a colored injection molded article such as an exterior part for automobiles having an excellent appearance.

[0006]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by using a composite film having a substrate layer having a specific composition. This has led to the present invention. That is, the gist of the present invention is a composite film in which a transparent layer, a colored layer, an adhesive layer, and a base layer are sequentially laminated, and the base layer is composed of the following (a) to (c) A paint substitute film characterized by that.

(A) Propylene-ethylene random copolymer (b) 10 to 300 parts by weight of low-density polyethylene or linear low-density polyethylene per 100 parts by weight of (a) (c) ((a) + (b)) 100 5 to 40 parts by weight of talc having an average particle diameter of 10 μm or less per part by weight

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Each layer structure of the coating substitute film Transparent layer The transparent layer, which is a constituent layer of the coating substitute film of the present invention,
Those made of a mixture of a fluororesin and a thermoplastic acrylic resin are preferred. As the fluororesin, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, or the like can be used, but polyvinylidene fluoride (PVDF) is used because of good moldability at the time of preliminary molding. ) Are preferred.

On the other hand, as the thermoplastic acrylic resin, various thermoplastic acrylic resins such as a methacrylic acid ester resin can be used. From the viewpoint of the scratch resistance of the molded product surface, the glass transition temperature (Tg) is used. Is 60 ° C
It is preferable that it is the above. The mixing ratio of the fluorine resin and the thermoplastic acrylic resin is preferably fluorine resin / thermoplastic acrylic resin = 20 to 80/80 to 20 in weight ratio. If the weight ratio is less than 20/80, the weather resistance is reduced and the impact resistance is also reduced.
If it exceeds 0/20, the scratch resistance of the coating substitute film is inferior, which is not preferable.

The thickness of the transparent layer is preferably from 20 to 100 μm. If the thickness is less than 20 μm, the appearance (particularly the sense of depth) of the molded article tends to decrease. However, it is not preferable in terms of cost. In the transparent layer, in addition to the fluororesin and the thermoplastic acrylic resin, other synthetic resins may be blended as long as the object of the present invention is not impaired. Further, various resin additives can be blended as required.

2. Coloring layer The coloring layer, which is a constituent layer of the coating substitute film of the present invention,
Those composed of a colorant and a thermoplastic acrylic resin or a mixture of a thermoplastic acrylic resin and a fluororesin are preferred in terms of weather resistance, pigment dispersibility, and the like. When a mixture of a thermoplastic acrylic resin and a fluororesin is used, it is preferable that the fluororesin be 90 parts by weight or less based on 100 parts by weight of the total amount of the thermoplastic acrylic resin and the fluororesin. If the amount of the fluororesin is more than 90 parts by weight, it is difficult to obtain sufficient adhesion to the base material layer via the adhesive layer, which is not preferable.

As the fluororesin and the thermoplastic acrylic resin, those described in the above “1. Transparent layer” can be used. As a coloring agent used for the coloring layer, an inorganic pigment,
It may be selected from organic pigments and the like, for example, carbon black, titanium oxide, kaolin clay, zinc white, red iron,
Permanent red, molybdenum orange, cobalt blue, ultramarine, phthalocyanine blue, manganese violet and the like. These pigments can be used alone or in combination of two or more. In addition, aluminum flakes and pearl pigments may be added to the above-mentioned pigments in order to obtain a metallic tone and a pearl tone.

The amount of the colorant varies depending on the type of the colorant and the desired color tone, but is usually about 0.1 to 50 parts by weight per 100 parts by weight of the resin component. The thickness of the colored layer is 5
~ 50 μm is preferred. If the thickness is less than 5 μm, the color of the stretched portion in the preforming tends to change greatly, which is not preferable. Further, even if the thickness is more than 50 μm, the effect of improving the performance is small and the cost is not preferable. In the coloring layer, in addition to the fluororesin and the thermoplastic acrylic resin, other synthetic resins may be blended as long as the object of the present invention is not impaired. Further, various resin additives can be blended as required.

3. Adhesive Layer The synthetic resin component forming the adhesive layer, which is a constituent layer of the coating substitute film of the present invention, may be any as long as it sufficiently adheres the base material layer and the colored layer. As such a material, a chlorinated polyolefin-based resin such as chlorinated polyethylene and chlorinated polypropylene (including these acrylic modified resins) is preferable. The adhesive layer may be a laminate, and as such a laminate, a laminate having a layer made of a thermoplastic acrylic resin and a layer made of a chlorinated polyolefin resin is preferable, and a laminate composed of these two layers is particularly preferable. preferable.

As the chlorinated polyolefin resin used for the adhesive layer, chlorinated polypropylene is particularly preferred. As the thermoplastic acrylic resin, those described in the above “1. Transparent layer” can be used. When the adhesive layer is a laminate having a layer made of a thermoplastic acrylic resin and a layer made of a chlorinated polyolefin-based resin, the layer made of the thermoplastic acrylic resin serves as a side in contact with the colored layer, and is made of a chlorinated polyolefin-based resin. It is preferable that the layer be on the side in contact with the base material layer and that the thermoplastic acrylic resin be the same synthetic resin as that used for the colored layer. Further, it is preferable that the chlorinated polyolefin-based resin is appropriately selected depending on the composition of the base material layer.

The thickness of the adhesive layer is preferably 3 to 30 μm. Furthermore, in addition to the chlorinated polyolefin-based resin and the thermoplastic acrylic resin, other synthetic resins may be added to the adhesive layer within a range not to impair the object of the present invention. Further, various resin additives can be blended as required.

4. Base material layer A base material layer, which is a constituent layer of the coating alternative film of the present invention,
It consists of the following (a) to (c). (A) Propylene / ethylene random copolymer (b) 10 to 300 parts by weight of low-density polyethylene or linear low-density polyethylene per 100 parts by weight (c) Per 100 parts by weight of ((a) + (b)) 5 to 40 parts by weight of talc having an average particle diameter of 10 μm or less

The ethylene content of the propylene / ethylene random copolymer is preferably 1 to 10% by weight, more preferably 2 to 6% by weight. When the low-density polyethylene or the linear low-density polyethylene is less than 10 parts by weight per 100 parts by weight of the propylene / ethylene random copolymer, the forming temperature range of the preliminary forming of the coating substitute film becomes narrow, and the formability deteriorates. On the other hand, when the amount is more than 300 parts by weight, adhesion to an injection molding resin for an automobile exterior part or the like becomes poor, and heat resistance and rigidity decrease. If the rigidity of the film is low, the shape retention of the preformed product is deteriorated, which causes a problem during injection molding. The blending amount of the low-density polyethylene or linear low-density polyethylene is preferably 15 to 100 parts by weight, particularly preferably 20 to 100 parts by weight, more preferably 25 to 6 parts by weight, per 100 parts by weight of the propylene / ethylene random copolymer.
0 parts by weight is more preferred.

The average particle size of the talc compounded in the base material layer is 1
It is 0 μm or less, preferably 5 μm or less, and the compounding amount is 5 to 40 parts by weight, preferably 10 to 30 parts by weight per 100 parts by weight of ((a) + (b)). If the average particle size of talc is larger than 10 μm, the appearance of the coating substitute film after molding is reduced, and even if the amount of talc is more than 40 parts by weight, the appearance after molding is reduced. Mixing a specific amount of talc having the above specific particle diameter also has an effect of improving the rigidity of the film, and is therefore useful from the viewpoint of shape retention of the preform.

Further, in order to improve the impact resistance required for automobile parts such as bumpers, ethylene / α
-It is preferable to blend an olefin copolymer rubber. The compounding amount of the copolymer rubber is preferably 5 to 40 parts by weight, more preferably 10 to 100 parts by weight of ((a) + (b)).
-20 parts by weight. When the blending amount of the ethylene / α-olefin copolymer rubber is less than 5 parts by weight, it is difficult to obtain the effect of improving the impact resistance, and when it exceeds 40 parts by weight, the appearance after molding is lowered and the film It is not preferable because the rigidity is reduced.

Α of ethylene / α-olefin copolymer rubber
-As olefin components, propylene, butene-
1, pentene-1, hexene-1, octene-1, 4-
Methylpentene-1, heptene-1 and the like can be mentioned, and one or more of these may be used. In addition, a crystal nucleating agent may be added to the base material layer in order to improve the appearance and the rigidity of the film. As the nucleating agent, a sorbitol-based nucleating agent generally used for polyolefin-based resins is useful, and the compounding amount is 0.1 to 3 parts by weight, preferably 0.2 to 1 part by weight per 100 parts by weight of the resin component. It is.

Further, in addition to each of the above resin components,
Other synthetic resins may be blended within a range that does not impair the purpose of the present invention. Further, various resin additives can be blended as required. The thickness of the base material layer is preferably 0.1 to 1 mm in order to suppress the shape retention after the pre-molding and the destruction due to the injection pressure during the injection molding and the melting due to the heat from the injection resin.

[0023] In the production the present invention paint substitute film, a transparent layer, a colored layer, each layer of the adhesive layer and the base layer can be prepared as follows. A release film may be used for forming the transparent layer, the coloring layer, and the adhesive layer. That is, the resin forming each layer is dissolved or dispersed in an organic solvent, a conventionally known reverse roll coating method,
It can be formed by successively coating on a release film by a comma coating method or the like. When the film thickness is small, a gravure coating method can also be used. Depending on the type of synthetic resin selected, it can be formed by extrusion molding.

The substrate layer may be formed into a film by a conventionally known T-die extrusion method or the like. After the release film / (transparent layer / colored layer / adhesive layer) formed by the above method and the base layer are laminated by thermal lamination at a temperature equal to or higher than the softening point of the resin used for the adhesive layer, the release film Is peeled off to obtain a coating substitute film of the present invention. As the release film, a polyethylene terephthalate film is preferable from the viewpoint of heat resistance during thermal lamination.

Parts (molded products) using a paint substitute film
The coating substitute film obtained by the above method is then preformed by thermoforming to obtain a three-dimensional formed body (preformed product) having a shape corresponding to the target component. As the thermoforming, a forming method such as vacuum forming, pressure forming, vacuum press forming, or the like is suitable, but vacuum forming is particularly simple and preferable.

In vacuum forming, for example, a coating substitute film is heated from both sides using far-infrared ceramic heaters, and then the mold is moved up, down, left and right, and a part of the heated coating substitute film is brought into contact with the mold. The air between the film and the mold is evacuated through a vacuum hole in the mold, and the coating alternative film surface is brought into close contact with the mold, fixed and shaped, and forced-cooled by a blower or the like. A method of cooling and solidifying is preferable.

In order to make the elongation of the film at the time of vacuum forming uniform over the whole part, after heating the coating substitute film, and before evacuation, air is blown from the direction in contact with the mold to form the heated film. There is also a method of molding while inflating into a hemispherical shape, which is particularly suitable for a part with a deep drawing. Next, injection molding of a part using the obtained coating substitute film has a shape corresponding to the shape of the three-dimensional preformed product obtained by preforming as described above, and is hard and high without surface defects. After inserting the preform into a pair of injection molds having a cavity having a glossy and polished surface, the mold is closed, and molten resin is injected and injected. In this case, it is necessary to take care that the preform fixed in the mold does not turn over or move from the mold. Also, to prevent the resin injected and injected from the gate from going around the cavity side from the preform,
In order to prevent wrinkles due to welding, the type of gate,
It is also necessary to consider the number, position, direction and shape. In particular, the type of the gate is preferably a direct gate, a submarine gate, or the like. The number of gates needs to take into consideration the shape of the component, the fluidity of the injection resin, and the like. After injecting and injecting the molten resin, the mold is cooled, the mold is opened, the molded product is taken out, and a component in which the above-mentioned preformed product is integrally incorporated as a colored coating layer is obtained.

[0028]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Examples 1 to 5 and Comparative Examples 1 to 6 a) Preparation of coating alternative film 1) Preparation of (transparent layer / colored layer / adhesive layer) On a release polyester film, the composition shown in Table 1 was applied. A layered product was prepared by successively applying layers in such a manner. Each layer was formed by dissolving or dispersing the compositions shown in Table 1 in toluene, methyl ethyl ketone, γ-butyrolactone, or a mixture thereof, and then performing the reverse roll coating method.

2) Preparation of base material layer A film was formed by a T-die extrusion method so as to have a thickness of 0.5 mm with the composition shown in Table 2 to obtain a base material layer. The substrate layer obtained in (2) is thermally laminated at a temperature of 150 ° C. and a pressure of 10 kg / cm on the adhesive layer side of the laminate obtained in 1) at a temperature of 150 ° C., and then the releasable polyester film is peeled off to replace the coating. A film was obtained.

B) Molding of parts After evaluating the temperature range in which the coating substitute film obtained in a) can be vacuum formed, vacuum forming is performed at an appropriate temperature.
A preform having the shape shown in FIG. 1 was produced. The vacuum forming temperature is
Specifically, Examples 1 to 4 and Comparative Examples 1 and 4 to 6 are respectively provided.
Is 150 ° C. in Example 5, 140 ° C. in Example 5, and 160 ° C. in Comparative Examples 2 and 3.

The approximate size of the preform is:
The length is 150 mm, the width is 70 mm, and the thickness is 8 mm. The prepared preform was inserted into a cavity surface of an injection mold and fixed, then clamped, and a polypropylene resin (BC2E manufactured by Nippon Polychem Co., Ltd.) was injected to obtain a part.

C) Evaluation of Parts 1) Evaluation of Vacuum Formability The temperature range in which vacuum forming is possible was evaluated using an evaluation die (vacuum forming die) having a draw ratio of 0.5, and the results are shown in Table-3. The evaluation results are as follows. Good moldability ○>△> × Poor moldability (wide molding temperature range) (narrow molding temperature range)

2) Evaluation of Appearance of Parts The parts obtained in b) were evaluated for appearance, 60 ° gloss and image definition, and the results are shown in Table 3. In addition, the evaluation criteria and the measuring method are as follows. -Appearance: Evaluated visually on a 10-point scale. Sharkless None ← 10,9 ・ ・ ・ 2,1 → Sharkless ・ 60 ° gloss: Handy gloss meter HG-268 manufactured by Suga Test Instruments Co., Ltd. ・ Image sharpness: Portable mapping by Suga Test Instruments Co., Ltd. Use of a sharpness measuring instrument HA-NSIC The gloss at 60 ° and the sharpness of the image were measured on a plane portion of a part in which a preform having the shape shown in FIG. 1 was integrally incorporated as a colored coating layer.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

The coating substitute film of the present invention has good preformability by thermoforming and excellent appearance after preformation, so that bumpers, side moldings, mudguards, wheel caps, spoilers, etc., which require design properties are required. It is suitably used for molded articles such as automotive exterior parts.

[Brief description of the drawings]

FIG. 1 is a perspective view of a preformed product of a coating substitute film of the present invention.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kennori Kanayama F-term (reference) 4F100 AC10C AC10H AK03J AK06C AK17A AK17B AK25A AK25B AK25J AK62C AK63C 4-1-1, Shiba 4-chome, Minato-ku, Tokyo AK64C AL03C AL05A AL06J AN02C BA03 BA07 BA10A BA10C BA13 BA15 CA13B CA23C DE01C DE01H EH17 GB32 HB00B JA20A JA20B JB16A JB16J JL01 JL10B JN01A YY00A YY00B YY00C YY00H

Claims (6)

[Claims] 1. A composite film in which a transparent layer, a colored layer, an adhesive layer and a substrate layer are sequentially laminated, wherein the substrate layer comprises the following (a) to (c): Alternative film. (A) Propylene / ethylene random copolymer (b) 10 to 300 parts by weight of low-density polyethylene or linear low-density polyethylene per 100 parts by weight (c) Per 100 parts by weight of ((a) + (b)) 5 to 40 parts by weight of talc having an average particle diameter of 10 μm or less 2. The coating substitute film according to claim 1, wherein the base material layer contains an ethylene / α-olefin copolymer rubber. 3. The coating substitute film according to claim 2, wherein the content of the ethylene / α-olefin copolymer rubber in the base layer is 5 to 40 parts by weight per 100 parts by weight of ((a) + (b)). . 4. The transparent layer is made of a fluororesin and a thermoplastic acrylic resin, and the thickness of the transparent layer is 20 to 100 μm.
The coating substitute film according to any one of claims 1 to 3, wherein m is m. 5. The colored layer comprises a coloring agent and a thermoplastic acrylic resin or a thermoplastic acrylic resin and a fluororesin, and the colored layer has a thickness of 5 to 50 μm.
5. The coating substitute film according to any one of items 4 to 4. 6. The adhesive layer has a layer made of a chlorinated polyolefin resin, or a layer made of a thermoplastic acrylic resin and a layer made of a chlorinated polyolefin resin.
The coating substitute film according to any one of claims 1 to 5.