JP6171785B2 - Resin parts for automobiles - Google Patents

Description

  The present invention relates to an automotive resin component in which a coating film is formed on a resin substrate.

  The inner and outer plates for automobiles are painted with various paint colors. Among them, when painting high-brightness paint colors such as white pearl mica and super white, and high-saturation paint colors such as super red and yellow, the color of the substrate is not sufficiently concealed. As a result, the target color tone may not be developed. For this reason, in the case of such a coating color, a color base layer (undercoat base layer) or a color primer layer such as white or light gray is previously applied as an undercoat, and a method of coloring in accordance with the base color or a top coat base. A method is adopted in which a layer is applied a plurality of times to develop a color by increasing the film thickness of the coating film.

For example, in the coating method of a resin molded product of Patent Document 1, when a resin molded product is coated with a high-saturation color top coat, a material-colored resin molded product having the same color as the top coat color is used as the resin molded product. It is disclosed. This eliminates the need for color intermediate coating, so that the high chroma of the top coat is not impaired even when the thickness of the top coat is less than or equal to the thickness of the concealed film and the base can be seen through. ing.
For example, in the roof molding of patent document 2, it is disclosed that the decoration layer which uses a polypropylene as a resin component is colored with the coloring agent contained in a shaping | molding raw material.

JP 60-206470 A JP 2001-58545 A

  However, in the coating method of the above-mentioned Patent Document 1, there is no disclosure about the composition and blending for obtaining the performance such as weather resistance necessary as a resin base material and how to create the color of the resin molded product. Not done. Moreover, in the said patent document 2, the surface of a roof molding is a colored polypropylene, and is easy to be damaged.

  When the resin molded product is composed of a white thermoplastic resin, when the color primer layer is made thin or the color base layer (undercoat base layer) is eliminated, the UV transmittance to the resin substrate surface through the coating film is reduced. It is necessary to determine the composition in consideration of discoloration and peeling of the coating film caused by a decrease in the weather resistance of the resin substrate surface due to the increase. Further, when the resin molded product is composed of a polypropylene-based colored resin, it is necessary to devise a technique for maintaining a state in which the surface is hardly damaged.

  The present invention was made in view of such a background, suppresses a decrease in weather resistance due to an increase in the ultraviolet transmittance to the surface of the resin substrate, and in a state where the color of the resin substrate can be seen through the surface, In the case of being made of a polypropylene-based colored resin, it is possible to obtain a target color tone and to obtain an automotive resin part that suppresses surface scratches.

One aspect of the present invention includes a resin substrate which is molded into a predetermined shape, which is applied to the surface of the resin base material, white color primer layer and the overcoat base layer applied to the surface of the color primer layer A resin component for automobiles in which the color of the surface of the resin substrate can be seen through the topcoat base layer and the color primer layer,
The resin base material is 0.13 to 0.25 parts by mass of the ultraviolet absorber and 0.48 to 0 of the light stabilizer with respect to 100 parts by mass of the resin mixture produced by blending the white pigment with the polypropylene resin. .95 parts by mass of a resin component for automobiles.

Another aspect of the present invention, possess a resin base material molded into a predetermined shape, the applied on the surface of the resin substrate, and the base top layer of white, and a clear layer, the clear layer and the the vehicle resin component seen through the color of the surface of the resin substrate via the base top layer,
The resin base material is 0.13 to 0.25 parts by mass of the ultraviolet absorber and 0.48 to 0 of the light stabilizer with respect to 100 parts by mass of the resin mixture produced by blending the white pigment with the polypropylene resin. .95 parts by mass,
The resin component for automobiles is characterized in that a modified surface imparting adhesion of the topcoat base layer is formed on the surface of the resin base material.

Still another embodiment of the present invention has a resin base material molded into a predetermined shape, and a white-based topcoat base layer applied to the surface of the resin base material. It is a resin part for automobiles where the color of the surface of the resin substrate can be seen through,
The resin base material is 0.15 to 0.30 parts by mass of an ultraviolet absorber with respect to 100 parts by mass of a resin mixture prepared by blending a white pigment with an AES resin, AAS resin or ASA resin. The resin component for automobiles contains 0.57 to 1.14 parts by mass of a stabilizer.
Still another aspect of the present invention includes a resin substrate which is formed into a predetermined shape, and the undercoat base layer of white, and a base top layer applied to the surface of the undercoat base layer, the overcoat A resin part for automobiles in which the color of the surface of the resin base material can be seen through the base layer and the undercoat base layer,
The resin base material is 0.15 to 0.30 parts by mass of an ultraviolet absorber with respect to 100 parts by mass of a resin mixture prepared by blending a white pigment with an AES resin, AAS resin or ASA resin. The resin component for automobiles contains 0.57 to 1.14 parts by mass of a stabilizer.

In the resin component for automobiles according to the above aspect, the composition of the resin base material and the coating film thickness of the color primer layer are devised.
Specifically, a white pigment such as titanium oxide is blended with a polypropylene-based resin, and a resin mixture having the same color tone as that obtained when the color primer layer is applied with a film thickness that can hide the color of the surface of the resin base material is formed. And 0.13-0.25 mass part of ultraviolet absorbers and 0.48-0.95 mass part of light stabilizer are contained with respect to 100 mass parts of this resin mixture, and a resin base material is formed. As a result, even when a white pigment such as titanium oxide is blended to form a resin substrate, and the color primer layer is thinly formed, ultraviolet rays that pass through the color primer layer and the overcoat base layer lower the weather resistance of the resin substrate. It is possible to suppress this.

In addition, when a white or light gray color primer layer is applied, the color primer layer is thinned to a coating thickness that can ensure adhesion to the resin substrate. And even when the color of the resin base material surface can be seen through the color primer layer, the target color tone is obtained and the deterioration of the weather resistance of the resin base material is suppressed.
As described above, the color primer layer is used for the purpose of attaching the coating film to the resin base material and does not need to be used for concealing the color of the resin base material. Further, the overcoat base layer reflects the color tone of the surface of the color primer layer, and can develop a target color tone.

  Therefore, according to the automotive resin component of the above aspect, the deterioration of the weather resistance due to the increase in the ultraviolet transmittance to the surface of the resin base material is suppressed, and the white resin base or light The gray color primer layer can be formed as a thin film, and a target color tone can be obtained in a state where the color of the resin base material can be seen through the surface.

In the resin parts for automobiles according to the other aspects, the composition of the resin base material and the elimination of the color primer layer are devised.
Specifically, the resin base material is formed in the same manner as in the case of the automotive resin component of the above aspect. As a result, even if a white pigment such as titanium oxide is blended to form a resin base material and the color primer layer is abolished, the UV light transmitted through the topcoat base layer and the clear layer or the clear layer is weather resistant to the resin base material. Can be suppressed.

Here, the adhesion of the topcoat base layer or the clear layer to the resin substrate is ensured by the modified surface formed on the resin substrate without applying a white or light gray color primer. And even when the color of the resin base material surface is seen through, the target color tone is obtained and the deterioration of the weather resistance of the resin base material is suppressed.
Thus, the adhesion of the topcoat base layer or the clear layer can be ensured by the modified surface formed on the resin base material, and the color primer layer is formed for the purpose of attaching the topcoat base layer or the clear layer to the resin base material. There is no need to use it. Moreover, the topcoat base layer and the clear layer, or the clear layer can reflect the color tone of the surface of the resin base material and develop a target color tone.

  Therefore, the same effect as the case of the automotive resin component of the one aspect can be obtained by the automotive resin component of the other aspect.

  By the way, when forming resin parts for automobiles with material color specifications with the color of the resin base material without painting the surface of the resin base material using polypropylene resin, the glossiness of the surface is applied. It is difficult to increase it to the same level as when In this case, it is also difficult to improve the scratch resistance indicating the difficulty of entering a scratch when rubbing the surface of a resin part for automobiles until it becomes equivalent to the case of coating. This problem of glossiness and scratch resistance is made by applying a clear layer on the surface of a resin base material that is made of a polypropylene resin that takes the above color tone and weather resistance into consideration and has been surface-modified to ensure adhesion. , Can be significantly improved.

In the above-described automotive resin component of another aspect, the resin base material composition and the undercoat base layer are eliminated.
Specifically, AES resin (acrylonitrile / ethylene propylene rubber / styrene copolymer), AAS resin (acrylonitrile / acrylonitrile rubber / styrene copolymer) or ASA resin (acrylonitrile / styrene / acrylate copolymer) A white pigment such as titanium oxide is blended, and a resin mixture having the same color tone as that obtained when the undercoat base layer is applied with a film thickness that can conceal the color of the surface of the resin substrate is prepared. And 0.15-0.30 mass part of ultraviolet absorbers and 0.57-1.14 mass part of light stabilizer are contained with respect to 100 mass parts of this resin mixture, and a resin base material is formed. Thus, even if a white pigment such as titanium oxide is blended to form a resin base material and the undercoat base layer is abolished, the ultraviolet light that passes through the top coat base layer reduces the weather resistance of the resin base material. Can be suppressed.

Even without applying a white or light gray undercoat base layer, the overcoat base layer reflects the color of the surface of the resin base material to obtain the target color tone and reduces the weather resistance of the resin base material. It is suppressed.
As described above, even if the undercoat base layer is not used, the overcoat base layer reflects the color tone of the surface of the resin base material and can develop a target color tone.

  Therefore, according to the automotive resin component of the above still another aspect, the white color or light against the white resin base material is suppressed by suppressing the deterioration of the weather resistance due to the increase in the ultraviolet transmittance to the surface of the resin base material. The application of the gray base coat base layer can be abolished, and the desired color tone can be obtained in a state where the color of the resin substrate can be seen through the surface.

Sectional drawing which shows the resin component for motor vehicles concerning Example 1 schematically. Sectional drawing which shows the resin component for motor vehicles concerning Example 2 roughly. Sectional drawing which shows the resin component for motor vehicles concerning Example 3 roughly. Sectional drawing which shows the other automotive resin component concerning Example 3 roughly. Sectional drawing which shows schematically the resin component for motor vehicles concerning the confirmation test 1 as the comparative product 1. FIG. Sectional drawing which shows schematically the resin component for motor vehicles concerning the confirmation test 2 as the comparative product 2. FIG. The graph which shows the surface glossiness (%) confirmed about the comparative products AC and the test product 4 concerning the confirmation test 4. FIG. The graph which shows the scratch resistance (%) confirmed about the comparative products AC and the test product 4 concerning the confirmation test 4. FIG.

A preferred embodiment of the above-described automotive resin part will be described.
In the resin component for automobiles according to the one aspect, the resin base material is a polypropylene resin, and the color primer layer is used in order to easily bond the topcoat base layer to the resin base material. This color primer layer is prepared by, for example, gray or black primer paint to obtain the target color tone in order to obtain the color tone that reflects the color of the color primer layer on the surface of the resin parts for automobiles. It is.
Further, the surface of the automotive resin component obtains a target color tone in a state where the topcoat base layer is applied to the color primer layer, or in a state where the topcoat base layer is applied to the color primer layer and further a clear layer is applied. By making the color tone of the resin substrate the same as the color tone of the color primer layer, the color primer layer can be coated with a thin film.

  In the automotive resin component of the other aspect, the resin base material is a polypropylene resin, and the resin base material is modified to facilitate the bonding of the topcoat base layer or the clear layer to the resin base material. Form a quality surface. This modified surface is obtained by forming functional groups that contain oxygen and contribute to the adhesion of the coating film on the surface of the resin base material. The modified surface can be formed by various processing methods. As this processing method, for example, there are a plasma discharge process, a flame process, a corona discharge process, an ozone process, and the like performed in an atmospheric pressure or vacuum state.

  In addition, in the automotive resin component of the other aspect, the surface of the automotive resin component obtains a target color tone in a state where the top coat base layer is applied to the resin base material and the clear layer is further applied. By making the color of the surface of the resin substrate the same color as the undercoat color base layer, the undercoat color base layer can be eliminated. Moreover, in the state which apply | coated the clear layer to the resin base material, surface glossiness and damage resistance can be provided, maintaining the color tone of the colored resin base material.

  In the automotive resin component according to the still another aspect, the resin base material is an AES resin, an AAS resin, or an ASA resin, and a primer layer for bonding the topcoat base layer and the resin base material is unnecessary. It is. And by making the color of the surface of a resin base material the same color as an undercoat color base layer, an undercoat color base layer can be made unnecessary.

Examples of the polypropylene resin include those obtained by homopolymerizing propylene, those obtained by copolymerizing propylene with other olefin resins, and those obtained by combining inorganic fillers. The polypropylene resin may be ethylene / propylene / diene rubber (EPDM), elastomer-modified propylene / ethylene block copolymer, or the like.
The AES resin, AAS resin, and ASA resin may each be a polymer alloy (PC / AES resin, PC / AAS resin, PC / ASA resin) with polycarbonate.

As said ultraviolet absorber (UVA), things, such as a benzotriazole type and a benzophenone type, can be used.
As the light stabilizer (HALS), ones such as hindered amines and hindered benzoates can be used.

  In the resin component for automobiles according to the above aspect, when the content of the ultraviolet absorber relative to 100 parts by mass of the resin mixture is less than 0.13 parts by mass, the ultraviolet absorption effect becomes insufficient, and the weather resistance of the resin base material It becomes difficult to ensure. Also, in this case, due to insufficient UV absorption effect, the discoloration that occurs on the surface of the resin substrate can be seen through the color primer layer and topcoat base layer (and clear layer), maintaining the target color tone. Difficult to do. Moreover, in this case, there is a possibility that the coating film may be peeled off due to a decrease in adhesion between the resin base material and the color primer layer. In addition, when the content of the light stabilizer is less than 0.48 parts by mass with respect to 100 parts by mass of the resin mixture, there is a problem similar to the case of the ultraviolet absorber.

  On the other hand, when the content of the ultraviolet absorber with respect to 100 parts by mass of the resin mixture is more than 0.25 parts by mass, there is a problem that mechanical properties such as impact resistance of the base resin are deteriorated, and ultraviolet rays with respect to the blending amount. There is a problem that the absorption effect is lowered and the cost effectiveness is lowered. Further, when the content of the light stabilizer is more than 0.95 parts by mass with respect to 100 parts by mass of the resin mixture, there is a problem similar to the case of the ultraviolet absorber.

  In the resin component for automobiles according to the other aspect described above, when the content of the ultraviolet absorber with respect to 100 parts by mass of the resin mixture is less than 0.13 parts by mass, and the content of the light stabilizer with respect to 100 parts by mass of the resin mixture Is less than 0.48 parts by mass, there is the same problem as in the case of the resin component for automobiles according to the above aspect. On the other hand, when the content of the ultraviolet absorber with respect to 100 parts by mass of the resin mixture exceeds 0.25 parts by mass, and when the content of the light stabilizer with respect to 100 parts by mass of the resin mixture exceeds 0.95 parts by mass. However, there are problems similar to those of the ultraviolet absorber.

  In the automotive resin part according to the still another aspect, when the content of the ultraviolet absorber relative to 100 parts by mass of the resin mixture is less than 0.15 parts by mass, the ultraviolet absorption effect becomes insufficient, and It becomes difficult to ensure weather resistance. Further, in this case, since the ultraviolet ray absorbing effect is insufficient, the discoloration generated on the surface of the resin base material is seen through the topcoat base layer (and the clear layer), and it is difficult to maintain the target color tone. It becomes. Moreover, in this case, there is a possibility that the coating film may be peeled off due to a decrease in adhesion between the resin base material and the topcoat base layer. Further, when the content of the light stabilizer is less than 0.57 parts by mass with respect to 100 parts by mass of the resin mixture, there is a problem similar to the case of the ultraviolet absorber.

  On the other hand, when the content of the ultraviolet absorber with respect to 100 parts by mass of the resin mixture is more than 0.30 parts by mass, there is a problem that the mechanical properties such as impact resistance of the base resin are deteriorated, and the ultraviolet rays with respect to the blending amount. There is a problem that the absorption effect is lowered and the cost effectiveness is lowered. Further, when the content of the light stabilizer is more than 1.14 parts by mass with respect to 100 parts by mass of the resin mixture, there is a problem similar to the case of the ultraviolet absorber.

The resin parts for automobiles can be various resin parts used as inner and outer plates of automobiles. Each automobile resin component may be a component such as a bumper cover, a side mudguard, a rear spoiler, or a garnish.
According to the L ^* C ^* h color system, C ^* (C value) representing saturation is the light reception angle in the multi-angle spectrocolorimeter according to the L ^* C ^* h color system. It can be 67 or more at 25 °, 70 or more at 45 °, and 65 or more at 75 °. The white color tone is defined by the content of titanium oxide or the like as a white pigment.
While the resin base material 2 can exhibit a white color tone mainly by a white pigment, the resin base material 2 may contain a black pigment such as carbon black.

  In addition, the white color tone is expressed as a color tone that passes through the color primer layer and the overcoat base layer (and clear layer) in the automotive resin component according to the above aspect by adjusting the color tone of the substrate surface. can do. In addition, the white color tone can be expressed as a color tone through the top coat base layer (and clear layer) in the automotive resin component of the other aspect by adjusting the color tone of the substrate surface. it can.

In the automotive resin part of the above aspect, the color primer layer can have a thickness of 7 μm or more, preferably 10 μm or more, and the overcoat base layer can have a thickness of 13 μm or more, preferably 15 μm or more. A clear layer having a thickness of 15 μm or more, preferably 20 μm or more can be applied to the surface of the overcoat base layer.
In this case, even if the white or light gray color primer layer is thinly formed, the surface color of the resin base material can be seen through and the color of the surface of the resin base material can be changed to the color tone of the coating film. Reflected, the target color tone can be obtained. Further, by applying a clear layer, the overcoat base layer can be protected.
Moreover, when the thickness of the color primer layer is less than 7 μm, the bonding strength between the color primer layer and the resin base material is weakened. Moreover, the top coat base layer and the clear layer can sufficiently exhibit their functions by having the above thickness.

In the resin component for automobiles according to the other aspect, the overcoat base layer has a thickness of 13 μm or more, preferably 15 μm or more, and the surface of the topcoat base layer has a thickness of 15 μm or more, preferably 20 μm or more. Can be applied. Moreover, when utilizing the material color which is the color tone of the resin base material, a clear layer having a thickness of 15 μm or more, preferably 20 μm or more can be applied to the surface of the resin base material.
In this case, the target color tone can be obtained by reflecting the color of the surface of the resin base material in the color tone of the coating film in a state where the color of the surface of the resin base material is seen through. Moreover, the topcoat base layer or the resin base material can be protected by applying the clear layer.
Moreover, the top coat base layer and the clear layer can sufficiently exhibit their functions by having the above thickness.

In the automotive resin component according to the still another aspect, the overcoat base layer has a thickness of 13 μm or more, preferably 15 μm or more, and the surface of the overcoat base layer has a thickness of 15 μm or more, preferably 20 μm or more. A clear layer can be applied.
In this case, the color of the surface of the resin base material can be seen in the state where the color of the surface of the resin base material is seen through without applying an undercoat base layer to the top base layer on the surface of the resin base material. The target color tone can be obtained by reflecting the color tone. Further, by applying a clear layer, the overcoat base layer can be protected.
Moreover, the top coat base layer and the clear layer can sufficiently exhibit their functions by having the above thickness.

Hereinafter, embodiments of resin parts for automobiles will be described with reference to the drawings.
Example 1
As shown in FIG. 1, the automotive resin component 1 of this example includes a resin base material 2 molded into a predetermined shape, a color primer layer 3 applied to the surface of the resin base material 2, and the surface of the color primer layer 3. And a clear layer 5 applied to the surface of the topcoat base layer 4. The resin base material 2 is 0.13 to 0.25 parts by mass of the ultraviolet absorber and 0.48 to 0 of the light stabilizer with respect to 100 parts by mass of the resin mixture produced by blending the white pigment with the polypropylene resin. .95 parts by mass is contained.

Hereinafter, the automotive resin component 1 of this example will be described in detail with reference to FIG.
The automotive resin component 1 of this example is a component molded as an outer plate of an automobile. The color primer layer 3 of this example has a thickness of 10 to 16 μm (13 ± 3 μm), and the topcoat base layer 4 of this example has a thickness of 15 to 21 μm (18 ± 3 μm). The topcoat base layer 4 in this example is formed as a paint color that reflects the color of the surface of the color primer layer 3 to obtain a target color tone. The topcoat base layer 4 may contain bright pigments such as aluminum flakes and mica in addition to titanium oxide as a white pigment. The thickness of the color primer layer 3 is determined to be equal to or more than the lower limit film thickness at which the color primer layer 3 can be stably bonded to the resin substrate 2. The thickness of the overcoat base layer 4 is determined within an appropriate range for expressing a target color tone.
A clear layer 5 having a thickness of 20 to 26 μm (23 ± 3 μm) is applied to the surface of the overcoat base layer 4. The thickness of the clear layer 5 is determined within an appropriate range in consideration of durability as a constituent coating film and a finished appearance.

  In the automotive resin part 1 of this example, the same as when the color primer layer 3 is coated with a film thickness that can hide the color of the surface of the resin base material 2 by blending titanium oxide as a white pigment with polypropylene resin. Make a resin mixture of different colors. And 0.13-0.25 mass part of ultraviolet absorbers and 0.48-0.95 mass part of light stabilizer are contained with respect to 100 mass parts of this resin mixture, and the resin base material 2 is formed. . Thus, even when titanium oxide is blended to form the resin base material 2 and the color primer layer 3 is thinly formed, the ultraviolet rays that pass through the color primer layer 3 and the topcoat base layer 4 are effective for improving the weather resistance of the resin base material 2. It can suppress that it falls.

  Thus, since the color primer layer 3 is used for the purpose of attaching a coating film to the resin base material 2 and does not need to be used for concealing the color of the resin base material 2, it can be thinned. Further, the overcoat base layer 4 reflects the color tone of the surface of the color primer layer 3 and can develop a target color tone.

  Therefore, according to the resin component 1 for automobiles of this example, a decrease in the weather resistance due to an increase in the ultraviolet transmittance to the surface of the resin base material 2 is suppressed, and a white system is compared with the white resin base material 2. Alternatively, a light gray color primer layer can be formed as a thin film, and a target color tone can be obtained in a state where the color of the resin substrate 2 can be seen through the surface.

(Example 2)
As shown in FIG. 2, the automotive resin component 1 of the present example includes a resin base material 2 formed in a predetermined shape, a topcoat base layer 4 applied to the surface of the resin base material 2, and a surface of the topcoat base layer 4. And a clear layer 5 applied to the surface. The resin base material 2 is 0.15 to 0.30 parts by mass of the ultraviolet absorber and 0.57 to 1 of the light stabilizer with respect to 100 parts by mass of the resin mixture produced by blending the white pigment with the AES resin. .14 parts by mass

Hereinafter, the automotive resin component 1 of this example will be described in detail with reference to FIG.
The automotive resin component 1 of this example is also a component molded as an inner and outer plate of an automobile. The topcoat base layer 4 in this example has a thickness of 15 to 21 μm (18 ± 3 μm). The topcoat base layer 4 in this example is formed as a coating color that reflects the color of the surface of the resin substrate 2 and obtains a target color tone. The topcoat base layer 4 may contain bright pigments such as aluminum flakes and mica in addition to titanium oxide as a white pigment. In this example, the resin base material 2 composed of an AES resin is used, and the color primer layer 3 for bonding the resin base material 2 and the topcoat base layer 4 is not necessary. The thickness of the overcoat base layer 4 is determined within an appropriate range for expressing a target color tone.
A clear layer 5 having a thickness of 20 to 26 μm (23 ± 3 μm) is applied to the surface of the overcoat base layer 4. The thickness of the clear layer 5 is determined within an appropriate range in consideration of durability as a constituent coating film and a finished appearance.

  In the automotive resin part 1 of this example, titanium oxide as a white pigment is blended with an AES resin, and the undercoat color base layer is applied in a film thickness that can hide the color of the surface of the resin substrate 2. Make a resin mixture in shades. And 0.15-0.30 mass part of ultraviolet absorbers and 0.57-1.14 mass part of light stabilizer are contained with respect to 100 mass parts of this resin mixture, and the resin base material 2 is formed. . Thereby, even if a white pigment such as titanium oxide is blended to form the resin base material 2 and the undercoat color base layer is abolished, the ultraviolet light transmitted through the topcoat base layer 4 reduces the weather resistance of the resin base material 2. Can be suppressed.

  Therefore, according to the resin component 1 for automobiles of this example, a decrease in weather resistance due to an increase in the ultraviolet transmittance to the surface of the resin base material 2 is suppressed, and a white system or light for the white resin base material 2 is suppressed. The application of the gray undercoat color base layer can be abolished, and the target color tone can be obtained in a state where the color of the resin substrate 2 can be seen through the surface.

(Example 3)
As shown in FIG. 3, the automotive resin component 1 of this example includes a resin base material 2 formed in a predetermined shape, a topcoat base layer 4 applied to the surface of the resin base material 2, and a surface of the topcoat base layer 4. And a clear layer 5 applied to the surface. The resin base material 2 is 0.13 to 0.25 parts by mass of the ultraviolet absorber and 0.48 to 0 of the light stabilizer with respect to 100 parts by mass of the resin mixture produced by blending the white pigment with the polypropylene resin. .95 parts by mass is contained. On the surface of the resin base material 2, a modified surface 21 that imparts adhesion of the topcoat base layer 4 is formed.

Hereinafter, the automotive resin component 1 of this example will be described in detail with reference to FIG.
The automotive resin component 1 of this example is also a component molded as an inner and outer plate of an automobile. The topcoat base layer 4 in this example has a thickness of 15 to 21 μm (18 ± 3 μm). The topcoat base layer 4 in this example is formed as a coating color that reflects the color of the surface of the resin substrate 2 and obtains a target color tone. The topcoat base layer 4 may contain bright pigments such as aluminum flakes and mica in addition to titanium oxide as a white pigment. The thickness of the overcoat base layer 4 is determined within an appropriate range for expressing a target color tone.
The modified surface 21 of the resin base material 2 is an oxide film formed by performing plasma discharge treatment in an atmospheric pressure state.

In this example, a resin substrate 2 made of a polypropylene resin is used, and a modified surface 21 is formed on the resin substrate 2 in order to eliminate the color primer layer 3.
A clear layer 5 having a thickness of 20 to 26 μm (23 ± 3 μm) is applied to the surface of the overcoat base layer 4. The thickness of the clear layer 5 is determined within an appropriate range in consideration of durability as a constituent coating film and a finished appearance.

  In the automotive resin part 1 of this example, a white pigment such as titanium oxide is blended with polypropylene resin, and the color primer layer 3 is applied in a film thickness that can hide the color of the surface of the resin substrate 2. Make a resin mixture of different colors. And 0.13-0.25 mass part of ultraviolet absorbers and 0.48-0.95 mass part of light stabilizer are contained with respect to 100 mass parts of this resin mixture, and the resin base material 2 is formed. . Thereby, even if a white pigment such as titanium oxide is blended to form the resin base material 2 and the color primer layer 3 is eliminated, the ultraviolet light transmitted through the topcoat base layer 4 and the clear layer 5 is weather resistant to the resin base material 2. It can suppress that the property will fall.

  Moreover, the adhesion of the topcoat base layer 4 can be ensured by the modified surface 21 formed on the resin base material 2, and the color primer layer 3 needs to be used for the purpose of attaching the topcoat base layer 4 to the resin base material 2. There is no. Moreover, the top coat base layer 4 reflects the color tone of the surface of the resin base material 2 and can develop a target color tone.

  Therefore, according to the resin component 1 for automobiles of this example, a decrease in weather resistance due to an increase in the ultraviolet transmittance to the surface of the resin base material 2 is suppressed, and a white system or light for the white resin base material 2 is suppressed. The application of the gray color primer layer 3 can be abolished, and a target color tone can be obtained in a state where the color of the resin substrate 2 can be seen through the surface.

Example 4
As shown in FIG. 4, the automotive resin component 1 of the present example includes a resin base material 2 made of a polypropylene resin and a clear layer 5 applied to the surface of the resin base material 2. On the surface of the resin base material 2, a modified surface 21 that provides adhesion of the clear layer 5 is formed.
Also in this example, the other configurations of the resin base material 2 and the clear layer 5 are the same as those of the third embodiment.

In this example, the adhesion of the clear layer 5 can be ensured by the modified surface 21 formed on the resin base material 2, and the color primer layer 3 is used for the purpose of attaching the clear layer 5 to the resin base material 2. There is no need. Further, the color tone of the automotive resin component 1 is formed by the color of the surface of the resin base material 2 that appears to pass through the clear layer 5. Moreover, by forming the clear layer 5, the surface gloss and scratch resistance of the automotive resin component 1 can be improved.
Also in this example, other functions and effects are the same as those in the third embodiment.

(Confirmation test 1)
In this confirmation test, as shown in FIG. 5, an automotive resin component 9 (comparative product 1) in which a white color primer layer 93 is formed on the surface of a black resin base material 92, and as shown in FIG. A comparison was made with the automotive resin part 1 (test product 1) of Example 1 in which the white color primer layer 3 was formed on the surface of the white resin base material 2.

The resin base material 92 in the comparative product 1 has a UV absorber of 0.10 parts by mass or less with respect to 100 parts by mass of a resin mixture obtained by blending a color pigment mainly composed of carbon black into a polypropylene resin and adjusting the color to black. A light stabilizer is contained at 0.38 parts by mass or less.
In Comparative Product 1, the color primer layer 93 was formed on the surface of the resin base 92 with a thickness of 25 μm, the mica base layer (overcoat base layer) 94 was formed with a thickness of 15 μm, and the clear layer 95 was formed with a thickness of 25 μm. Then, when the color tone of the surface of the clear layer 95 was measured, L ^* = 92.33, a ^* = − 1.27, and b ^* = 0.23.

The resin base material 2 in the test product 1 is in the range of 0.13 to 0.25 parts by mass of the ultraviolet absorber with respect to 100 parts by mass of the resin mixture in which titanium oxide or the like as a white pigment is blended with polypropylene resin. The light stabilizer is contained in the range of 0.48 to 0.95 parts by mass.
In the test product 1, the color primer layer 3 was formed on the surface of the resin substrate 2 with a thickness of 10 μm, the mica base layer (overcoat base layer) 4 was formed with a thickness of 15 μm, and the clear layer 5 was formed with a thickness of 25 μm. As the color primer layer 3, the mica base layer 4 and the clear layer 5, the same color primer layer 93, mica base layer 94 and clear layer 95 of the comparative product 1 were used. And when the color tone of the surface of the clear layer 5 was measured, it became L ^* = 92.20, a ^* = − 1.24, b ^* = 0.06. The color difference ΔE ^* between the comparative product 1 and the test product 1 was 0.22, and there was almost no difference in the color tone between them, and visual discrimination was impossible.

In this confirmation test, the color primer is used in a state where the resin base material 2 is changed from a black system containing a color pigment mainly composed of carbon black to a white system mainly composed of titanium oxide, and the color of the resin base material 2 is seen through. The color tone was the same as when layer 3 was applied with a base concealing film thickness. As a result, the thickness of the color primer layer 3 could be significantly reduced to a thickness necessary for bonding the resin substrate 2 and the coating film.
And the increase in ultraviolet transmittance due to the reduction in the thickness of the color primer layer 3, and the weather resistance due to the reduction of the carbon black content from the main component of carbon black or the change of the color pigment formulation to the titanium oxide main component. The decrease in property can be compensated by increasing the blending amounts of the ultraviolet absorber and the light stabilizer.

(Confirmation test 2)
In this confirmation test, as shown in FIG. 6, an automotive resin component 9 (comparative product 2) in which a white undercoat color base layer 941, an overcoat base layer 94, and a clear layer 95 are formed on the surface of a black resin base material 92. As shown in FIG. 2, the automotive resin component of Example 2 in which the white base coat base layer 4 was formed without applying the white base coat base layer on the surface of the white resin base 2. Comparison with 1 (test product 2) was performed.

The resin base material 92 in the comparative product 2 is obtained by blending an AES resin with a color pigment mainly composed of carbon black and adjusting the color to black. The resin base material 92 has an ultraviolet absorber of 0.10 parts by mass or less. The light stabilizer is contained at 0.40 parts by mass or less.
In Comparative Product 2, the undercoat color base layer 941 was formed on the surface of the resin base 92 with a thickness of 25 μm, the mica base layer (overcoat base layer) 94 was formed with a thickness of 15 μm, and the clear layer 95 was formed with a thickness of 25 μm. Then, when the color tone of the surface of the clear layer 95 was measured, L ^* = 92.33, a ^* = − 1.27, and b ^* = 0.23.

The resin base material 2 in the test product 2 has an ultraviolet absorber of 0.15 to 0.30 parts by mass with respect to 100 parts by mass of a resin mixture formed by blending titanium oxide or the like as a white pigment with an AES resin. In the range, the light stabilizer is contained in the range of 0.57 to 1.14 parts by mass.
The test product 2 was formed on the surface of the resin base material 2 with a mica base layer (overcoat base layer) 4 having a thickness of 15 μm and a clear layer 5 having a thickness of 25 μm. As the mica base layer 4 and the clear layer 5, the same ones as the mica base layer 94 and the clear layer 95 of the comparative product 2 were used. And when the color tone of the surface of the clear layer 5 was measured, it became L ^* = 92.02, a ^* = − 1.20, b ^* = 0.20. The color difference ΔE ^* between the comparative product 2 and the test product 2 was 0.32, and there was almost no difference in color tone between them, and visual discrimination was impossible.

In this confirmation test, the resin base material 2 is changed from a black system in which a color pigment mainly composed of carbon black is mixed to a white system mainly composed of titanium oxide, and the resin base material 2 is coated without applying the undercoat color base layer 941. The surface color was set to the same color tone as when the undercoat color base layer 941 was applied. As a result, the undercoat color base layer 941 could be eliminated.
And the increase in ultraviolet light transmittance due to the abolition of the undercoat color base layer 941, and the decrease in weather resistance due to the reduction of the carbon black content from the main component of carbon black or the change of the color pigment formulation to the main component of titanium oxide. Can be supplemented by increasing the blending amount of the ultraviolet absorber and the light stabilizer.

(Confirmation test 3)
In this confirmation test, the automotive resin component 1 (test product 1) shown in the confirmation test 1 and a white base coat base on the modified surface 21 of the white resin base 2 as shown in FIG. A comparison was made with the automotive resin part 1 of Example 3 in which the layer 4 was formed (test product 3).

The resin base material 2 in the test product 3 is in the range of 0.13 to 0.25 part by mass of the ultraviolet absorber with respect to 100 parts by mass of the resin mixture in which titanium oxide or the like as a white pigment is blended with polypropylene resin. The light stabilizer is contained in the range of 0.48 to 0.95 parts by mass.
The test product 3 was formed on the modified surface 21 of the resin base material 2 with a mica base layer (overcoat base layer) 4 having a thickness of 15 μm and a clear layer 5 having a thickness of 25 μm. As the mica base layer 4 and the clear layer 5 of the test product 3, the same as the mica base layer 4 and the clear layer 5 of the test product 1 were used. And when the color tone of the surface of the clear layer 5 of the test product 3 was measured, it became L ^* = 92.02, a ^* = − 1.20, b ^* = 0.20. The color difference ΔE ^* between the test product 1 and the test product 3 was 0.23, and there was almost no difference in the color tone between them, and visual discrimination was impossible.

In this confirmation test, the resin base material 2 is changed from a black system in which a color pigment mainly composed of carbon black is mixed to a white system mainly composed of titanium oxide, and a modified surface 21 which is a surface modified layer is added. Even if the color primer layer 3 was not applied, the color of the surface of the resin base material 2 was the same as that when the color primer layer 3 was applied. Thereby, the color primer layer 3 was able to be abolished.
And the increase in ultraviolet transmittance due to the abolition of the color primer layer 3, and the decrease in the weather resistance due to the reduction of the carbon black content from the main component of carbon black or the change of the color pigment formulation to the titanium oxide main component Can be supplemented by increasing the blending amount of the ultraviolet absorber and the light stabilizer.

(Confirmation test 4)
In this confirmation test, as shown in FIG. 4, the automotive resin component 1 (test product 4) of Example 4 in which the clear layer 5 was formed on the modified surface 21 of the white resin substrate 2, and the polypropylene-based resin Surface glossiness and scratch resistance were confirmed for an automotive resin component (comparative product 3) composed only of a resin base material 2 composed of resin.
For Comparative product 3, the surface gloss and scratch resistance were confirmed for block polypropylene (Comparative product A), block polypropylene (Comparative product B), and homopolypropylene (Comparative product C) different from Comparative product A, respectively.

  The surface glossiness indicates the reflectance (%) of light when light is applied to the surface of an automotive resin component at an incident angle of 20 ° and received at a light receiving angle of 20 ° as surface glossiness (%). Scratch resistance is the difference in the rate of change in light reflection (%) when light is applied at an incident angle of 20 ° and received at an angle of 20 ° before and after rubbing the surface of an automotive resin part with a car wash brush. The smaller the numerical value, the better the scratch is less likely to enter.

In FIG. 7, the surface glossiness (%) confirmed about the comparison goods AC and the test goods 4 is shown. As shown in the figure, it was confirmed that the test product 4 was superior in surface gloss compared to the comparative products A to C. FIG. 8 shows the scratch resistance confirmed for the comparative products A to C and the test product 4. As shown in the figure, it was confirmed that the test product 4 was superior in scratch resistance compared to the comparative products A to C.
From the above results, it was possible to confirm the excellent effect of forming the clear layer 5 on the resin base material 2 composed of polypropylene resin.

DESCRIPTION OF SYMBOLS 1 Automotive resin part 2 Resin base material 21 Modified surface 3 Color primer layer 4 Top coat base layer 5 Clear layer

Claims (4)

It has a resin substrate molded in a predetermined shape, which is applied to the surface of the resin substrate, and the white color primer layer, a base top layer applied to the surface of the color primer layer, the overcoat A resin part for automobiles in which the color of the surface of the resin base material can be seen through the base layer and the color primer layer,
The resin base material is 0.13 to 0.25 parts by mass of the ultraviolet absorber and 0.48 to 0 of the light stabilizer with respect to 100 parts by mass of the resin mixture produced by blending the white pigment with the polypropylene resin. .95 parts by mass of resin parts for automobiles A resin base material molded into a predetermined shape; a white base coat base layer applied to a surface of the resin base; and a clear layer; and the resin through the clear layer and the top coat base layer It is a resin part for automobiles where the color of the surface of the substrate can be seen through,
The resin base material is 0.13 to 0.25 parts by mass of the ultraviolet absorber and 0.48 to 0 of the light stabilizer with respect to 100 parts by mass of the resin mixture produced by blending the white pigment with the polypropylene resin. .95 parts by mass,
An automotive resin part, wherein a surface of the resin base material is provided with a modified surface for imparting adhesion of the topcoat base layer. A resin base material molded into a predetermined shape and a white base coat base layer applied to the surface of the resin base, and the color of the surface of the resin base is transparent through the base coat base layer. Visible plastic parts for automobiles,
The resin base material is 0.15 to 0.30 parts by mass of an ultraviolet absorber with respect to 100 parts by mass of a resin mixture prepared by blending a white pigment with an AES resin, AAS resin or ASA resin. An automotive resin component comprising 0.57 to 1.14 parts by mass of a stabilizer. And the resin base material molded into the predetermined shape, has a subbing base layer of white, and a base top layer applied to the surface of the undercoat base layer, through the overcoat base layer and the undercoat base layer above It is a resin part for automobiles where the color of the surface of the resin substrate can be seen through,
The resin base material is 0.15 to 0.30 parts by mass of an ultraviolet absorber with respect to 100 parts by mass of a resin mixture prepared by blending a white pigment with an AES resin, AAS resin or ASA resin. An automotive resin component comprising 0.57 to 1.14 parts by mass of a stabilizer.

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