JP2000327835A - Resin molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To advantageously reduce unevenness of color tones in the appearance by composing a resin molded article of a base material, composed essentially of a resin, and glossy micro-bodies which are mixed at least in the surface layer side of the base material so as to adjust the color tones of the surface layer of the base material, the glossy micro-bodies being composed of a plate- like object having a three-dimensionally curved part. SOLUTION: A resin molded article A comprises a base material 1 composed essentially of a polypropylene which is a light-transmitting resin, and a large number of glossy micro-bodies 3 mixed in the base material 1. Even when a weld part 100 is formed in the resin molded article A, it is possible to prevent generation of a large difference in orientations between glossy micro-bodies 3 (3A) in one weld part 101 and glossy micro-bodies 3 (3B) in the other weld part 102, both parts being adjacent to each other via the weld part 100 as the boundary. Thus, unevenness of metallic color tones in the appearance of the resin molded article having a weld part 100 as a boundary is advantageously reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded article containing glossy fine particles for adjusting the appearance color tone.

[0002]

2. Description of the Related Art As a resin molded article, a resin molded article in which glossy fine bodies are mixed with a resin base material is known. In this resin molded product, the color tone of the resin molded product is adjusted by the glossy fine body.
For example, the color tone of the resin molded product can be made metallic. As this kind of technology, Japanese Patent Application Laid-Open No. Hei 9-164543 discloses a technique in which a two-dimensional disk-shaped thermoplastic resin mixed with glossy fine particles is used, and the resin is loaded into a cavity of a mold by injection molding. And a method of manufacturing the same.

As described above, when two-dimensional disc-shaped glossy fine particles are mixed in a resin molded product, the reflection area and the amount of reflected light with respect to external light can be reduced as compared with the case where the glossy fine particles are spherical. It is ensured well, and the color tone of the appearance of the resin molded product is improved.

[0004]

Although the above technique improves the appearance color tone of a resin molded product, the two-dimensional mere disk-shaped glossy fine body is employed, so that the influence of the flow direction of the resin and the like is not obtained. This may cause a difference in the orientation of the glossy fine bodies. When the difference in the orientation of the glossy fine bodies is large, unevenness in color tone of the resin molded product is likely to occur.

[0005] The color tone unevenness is inferred as follows, taking as an example a difference in the orientation of the glossy fine body in the vicinity of the weld portion, which is the trace of collision of the resin flow. FIG. 8 shows a conceptual diagram of the orientation form of the glossy fine body in the resin molded product. When the resin containing the glossy fine particles is solidified, a resin molded product having surfaces 100a and 100c is obtained. As shown in FIG. 8, when molding a resin molded product, a resin flow from one side (X1 direction) may collide with a resin flow from a different direction (X2 direction). When the resins flowing from different directions collide with each other as described above, a trace of the collision tends to remain. The collision trace is generally called a weld portion 100 after the resin is solidified.
When the weld portion 100 exists in the resin molded product, the glossy fine body 200 (200A) on the surface layer on one side 101 of the weld portion 100 and the other 10 of the weld portion 100 are formed.
An alignment difference is likely to occur between the glossy fine body 200 (200B) on the surface layer on the second side. The reason is 10
This is because the resin flow direction differs between the first side and the other 102 side. Note that the difference in the orientation of the glossy fine bodies 200 mainly occurs near the surfaces 100a and 100c of the resin molded product.
It is considered that a difference in the orientation of the glossy fine bodies 200 hardly occurs inside the resin molded product.

As described above, the glossy fine bodies 200A, 20A
When there is an orientation difference of 0B, when the incident lights 300 and 302 enter the resin molded product from the same direction,
The reflection angle of the incident light 300 incident on one side and the reflection angle of the incident light 302 incident on the other 102 side tend to be different. Also, for the incident lights 300 and 302 in the same direction, the same degree of light reflectivity by the glossy fine bodies 200A and 200B is secured. However, the incident light 306 from the opposite direction is
Since it is along the direction of 00B, the incident light 306 is hardly reflected by the glossy minute body 200B.

[0007] Therefore, when the resin molded product is visually recognized by the naked eye, color tone unevenness of the appearance of the resin molded product may occur from the weld portion 100 as a boundary. Note that the main cause of the color tone unevenness is not limited to the welded portion 100 but is the glossy fine body 20.
It may also occur in other portions where a 0 orientation difference occurs. The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a resin molded product that is advantageous in reducing color tone unevenness in appearance.

[0008]

Means for Solving the Problems A resin molded product according to the present invention comprises a base material mainly composed of a resin and a glossy fine body mixed at least on the surface side of the base material to adjust the color tone of the surface layer of the base material. And wherein the glossy minute body is formed of a plate-like body having a curved portion curved three-dimensionally.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The base material of the resin molded article according to the present invention contains a resin as a main component. As the resin, polypropylene, polyethylene, ABS, polyamide, polyimide,
Various thermoplastic resins such as polyamide imide, polyester, polystyrene, polyvinyl chloride, and polyoxymethylene (POM) can be employed. Alternatively, a thermosetting resin such as a phenol resin and an epoxy resin can be used as the resin. When the base material is a thermoplastic resin, the resin can be easily regenerated. As the resin, a resin having high transmissivity for visible light can be used.

The base material is a colorant, a filler, a plasticizer, a foaming agent,
At least one of additives such as an ultraviolet absorber, a light stabilizer, an antistatic agent, an antioxidant, and a lubricant can be appropriately contained. Therefore, at least one of rubber, talc and barium sulfate
Seeds can be included as appropriate. Black pigments as colorants,
A black dye can be employed. As the colorant, an achromatic color system such as black or white, or a chromatic color system such as red can be used as necessary.

As a colorant exhibiting black, black pigments such as carbon black, acetylene black, iron black (iron sesquioxide) and graphite, black dyes, and composite oxide pigments can be used. If necessary, a pulverized product of a material (a thermosetting resin or the like) colored in a milled black such as carbon fiber can also be used. In addition, at least one of barium sulfate, zinc white, zinc sulfide, calcium carbonate, and the like may be added to the base material together with the above-described black colorant.

The glossy minute body is a minute body for adjusting the color tone of the appearance of the resin molded product. The glossy fine bodies are mixed at least on the surface layer side of the substrate. Therefore, the glossy fine bodies may be mixed in the entire substrate, or may be mixed only on the surface layer side of the substrate. The glossy minute body is formed of a plate-like body having a curved portion that is curved (including curved) three-dimensionally. Therefore, the glossy fine body can be configured by bending (including bending) a fine plate-like portion.

The three-dimensionally curved glossy minute body may be a plate-like minute body having a curved portion at least partially curved in the cross section of the glossy minute body, or a plate-like minute body entirely curved. Can be adopted. As the above-mentioned glossy minute body, a bowl-shaped minute body, a pseudo-bowl-shaped minute body, a half-bowl-shaped minute body exhibiting about half of a bowl, a dish-shaped minute body, a pseudo-dish-shaped minute body, a dish-shaped minute body A half-bowl-shaped minute body, a saddle-shaped minute body, a pseudo-saddle-shaped minute body, and a half-saddle-shaped minute body, which is about half the saddle-shaped body, are provided.

Therefore, the glossy fine particles according to the present invention include:
In the cross section of the glossy fine body, one having a bowl shape, a dish shape, a bow shape, a C shape, an S shape, a wave shape, or the like can be adopted. For example, the above-mentioned glossy minute body is obtained by appropriately applying a pressing force in the thickness direction to a two-dimensional plate-like minute body (for example, a disk shape, an elliptical plate shape, a square plate shape, a polygonal plate shape, etc.). Can be obtained by

In the resin molded product according to the present invention, a plurality of types of glossy fine bodies such as the above-mentioned bowl type, saddle type, and dish type may be mixed in the base material, or a single type of glossy fine The body may be mixed with the base material. In some cases, a form in which a spherical or disk-shaped glossy fine body is mixed with a base material together with a glossy fine body of a bowl shape, a saddle shape, a dish shape, or the like may be used. FIG.
FIG. 6 to FIG. 6 show typical examples of glossy fine bodies. FIG. 4 shows an example of the appearance of a bowl-shaped glossy fine body. The bowl-shaped glossy minute body 10 has a three-dimensionally curved concave surface 10a
A thin plate-like body 10d provided with a curved portion 10c having a convex surface and another surface 10b, and one surface 10d of the plate-like body 10d.
and a depression 10e formed on the side a.

FIG. 5 shows an example of the appearance of a saddle-shaped glossy fine body. The saddle-shaped glossy minute body 13 has a thin plate-like body 13d provided with a curved portion 13c having one surface 13a and another surface 13b curved three-dimensionally, and a concave portion formed on the surface 13a side. 13e and a recess 13f formed on the other surface 13b side
With FIG. 6 shows another example of the appearance of a saddle-shaped glossy fine body. The saddle-shaped glossy fine body 16 includes a thin plate-like body 16d having a curved portion 16c having a three-dimensionally curved one surface 16a and another surface 16b, and a concave portion 16e formed on the one surface 16a side. A recess 16f formed on the other surface 16b side
With

In the resin molded article according to the present invention, the size of the above-mentioned glossy minute body is not particularly limited, and is appropriately selected in consideration of the type and use of the resin molded article, the kind and use of the glossy minute body, and the like. . For example, the upper limit value of the average diameter of the glossy fine bodies (the average diameter of the projection form) is 200 μm or 100 μm.
m, 50 μm, and 30 μm can be adopted, and 1 μm, 2 μm, 5 μm, and 10 μm can be adopted as the lower limit. Therefore, the total average diameter of the glossy fine particles is 5
９０90 μm can be adopted. However, it is not limited to the above numerical values.

In the case of the bowl-shaped glossy fine body 10 shown in FIG. 4, the average diameter D1 of the glossy fine body 10 (the average diameter of the projection form) may be 5 to 90 μm. However, it is not limited to the above numerical values. When the height of the glossy fine body 10 is H1, the ratio of D1 to H1 is relatively 1 and the diameter D1 is relatively 1. When the height H1 is in the range of 0.01 to 1.0, 0. .1 to 0.8. However, it is not limited to the above numerical values. The glossy fine bodies shown in FIGS. 5 and 6 can be similarly defined.

The average thickness of the glossy fine body can be appropriately selected in consideration of the type and use of the resin molded article, the type and use of the glossy fine body, and can be, for example, 0.1 to 20 μm. However, it is not limited to this. Since the glossy microparticles according to the present invention are three-dimensionally curved, the difference in orientation of the glossy microparticles due to the flow of the resin, compared to the case where a two-dimensional plain glossy microparticle is used. Is less likely to occur. Therefore, it is advantageous to suppress the occurrence of a difference in the orientation of the glossy fine bodies in a state where the glossy fine bodies are mixed in the base material.

The material of the glossy fine body is not particularly limited as long as it has gloss. In order to secure the metallic tone of the appearance of the resin molded product, as a material of the glossy fine body, a metal-based material such as aluminum, titanium, iron, zinc, tin, nickel, silver, gold, copper, and an alloy thereof,
Alloys such as brass, brass, and stainless steel can be employed. Alternatively, synthetic pearl, mica, or the like can be used as the material of the glossy fine body.

The proportion of the glossy fine particles to be added to the resin molded product is not particularly limited, and is appropriately selected in consideration of the type and use of the resin molded product, the type and use of the glossy fine particles, and the like. Assuming that the resin molded product is 100%,
The upper limit of the addition ratio of the glossy fine particles is 0.80%,
1.0%, 2.0%, 5.0% can be appropriately adopted, and the lower limit is 0.01%, 0.10%, 0.30%.
% And 0.50% can be appropriately adopted. Therefore, the addition ratio of the glossy fine particles can be, for example, 0.20% to 0.90%. However, the addition ratio of the glossy fine particles is not limited to the above-mentioned numerical value.

When the resin molded product contains a colorant, the ratio of the colorant to be added is not particularly limited, and is appropriately selected in consideration of the type and use of the resin molded product, the type and use of the colorant, and the like. . Assuming that the resin molded product is 100%, the weight ratio of the coloring agent is 0.0001% to 0.1%,
In particular, 0.0003 to 0.05% can be adopted. Therefore, the addition ratio of the coloring agent is, for example, 0.0005% or more.
0.06%. However, the addition ratio of the coloring agent is not limited to the above value.

When the resin molded product contains rubber, the rubber can be, for example, 10% to 30% by weight when the resin molded product is 100%. When the resin molded product contains talc, when the resin molded product is 100%,
Talc can be, for example, 5% to 20% by weight. The resin molded product according to the present invention can be molded by a known molding method such as injection molding, extrusion molding, compression molding, and blow molding. Further, a clear paint or a transparent smoke paint can be applied to the surface of the resin molded product to laminate a transparent coating film.

The resin molded article according to the present invention can be applied to exterior parts and interior parts in vehicles, general equipment, industrial equipment and the like.
In a vehicle, for example, the present invention can be applied to a bumper, a cover, a scuff plate, a cluster, and the like.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a cross section near the surface layer of the resin molded product A. The resin molded product A according to the present embodiment has a base material 1 mainly composed of polypropylene, which is a resin having a light-transmitting property, and a large number of glossy fine bodies 3 mixed in the base material 1.

The substrate 1 contains carbon black, talc, and rubber in addition to polypropylene. The composition of the resin molded product A is about 74% by weight of the resin when the resin molded product is 100%.
%, Talc about 10%, rubber about 15%, glossy fines 3
Is about 0.7% and carbon black is about 0.007%. The glossy minute body 3 is a minute aluminum-based metal plate-like body mixed in order to improve the color tone of the appearance of the substrate 1, and can contribute to making the appearance of the resin molded product A a metallic color tone. In the glossy fine body 3, the average diameter D (the average diameter of the projection form) is in the range of about 20 to 70 μm, the average height H is in the range of about 5 to 35 μm, and the thickness is about 0.5 to 1 μm.
It is in the range of 0 μm.

The glossy fine body 3 used in this embodiment has a thin plate shape that is three-dimensionally curved. Therefore, the glossy fine body 3
Is formed of a thin plate having a bent portion 3c that is three-dimensionally curved. Therefore, as shown in FIG. 1, in the cross section of the glossy minute body 3, the glossy minute body 3 has an arcuate shape, a concave surface concaved in an arc shape, and a convex surface protruding in an arc shape. Surface 3b.

In this embodiment, as shown in FIGS. 2 and 3, the mold surfaces 51 and 52 for forming the molding cavity 50 are formed.
Is used. Then, using a fluid material containing the base material 1 and the glossy fine body 3 as main components, the fluid material is injected into the molding cavity 50 of the molding die 5 at a predetermined injection molding pressure from an unillustrated injection port of the molding die 5. It is loaded and solidified by injection molding. Then, the resin mold A is obtained by releasing the mold 5. Many glossy microscopic bodies 3 are mixed in the surface layer and inside of the resin molded product A.

As described above, in this embodiment, since the glossy minute body 3 has a three-dimensionally curved thin plate shape, it is compared with the case where a simple two-dimensional disk-like glossy minute body is used. Thus, it is advantageous to suppress the glossy minute body 3 from being oriented in a specific direction due to the influence of the resin flow. Therefore, in the present embodiment, even if there is a difference in resin flow or a collision at the time of molding, in the resin molded product A, the glossy fine particles 3
Can be suppressed. Therefore, it is advantageous for reducing unevenness of the metallic color tone in the appearance of the resin molded product A when visually recognized with the naked eye.

In this embodiment, even when the welded portion 100 is formed on the resin molded product A as shown in FIG.
01 side, the glossy minute body 3 (3A) and the weld portion 1
Glossy minute body 3 on the other 102 side with 00 as the boundary
With (3B), it is possible to prevent a large alignment difference from occurring. Therefore, it is advantageous to reduce metallic color tone unevenness in the appearance of the resin molded product A at the boundary of the weld portion 100.

As described above, in the present embodiment, it is advantageous to reduce the unevenness of the color tone while reducing the blending amount of the glossy fine particles 3, so that the consumption of the glossy fine particles 3 can be reduced. This is advantageous. Therefore, the price of the resin molded product A is reduced,
Further, it can contribute to securing the strength of the resin molded product A. Further, a transparent coating film may be laminated on the surface 100a of the resin molded product A by clear coating or the like. In this embodiment, since the color tone unevenness of the appearance of the resin molded product A can be reduced, it is advantageous for simplifying or eliminating the above-mentioned coating film.

(Application Example) FIG. 7 shows an application example. This example is applied to a buffer bumper 7 mounted on a vehicle. The bumper 7 is made of a polypropylene resin as a base material, and includes two ends 71 and 72 and a bridge 73 connecting the ends 71 and 72. At the time of injection molding, using a fluid molding material containing resin, talc, rubber, a colorant and glossy fine particles 3, through an injection port provided in a molding die,
The molding material is charged into a molding cavity of a mold and integrally molded. Since the bumper 7 includes the glossy minute body 3 according to the present invention, the bumper 7 has an appearance of a metallic color tone, and the color tone unevenness is suppressed.

(Supplementary Note) The following technical idea can be understood from the above description. : In a resin molded product including a base material mainly composed of a resin and a glossy fine body mixed on at least the surface layer side of the base material and adjusting the color tone of the surface layer of the base material, the glossy fine body has a curved plate shape. A resin molded article characterized by being constituted by a body.

In the above or claim 1, the glossy minute body may be a bowl-shaped minute body, a pseudo-bowl-shaped minute body, a half-bowl-shaped minute body representing about half of a bowl, a dish-shaped minute body,
Pseudo-dish-shaped micro-body, semi-bowl-shaped micro-body that shows about half of the plate, saddle-shaped micro-body, pseudo-saddle-shaped micro-body, semi-saddle-shaped micro-body that shows about half of the saddle-shaped , At least one of which is a resin molded product.

The glossy microparticle as described above or in claim 1, wherein the cross section of the glossy microparticle has a bowl shape,
A resin molded product having one of a dish shape, a bow shape, a C shape, an S shape, a wave shape, and a pseudo shape thereof. : A three-dimensionally curved piece in a resin molded product including a base material mainly composed of a resin and a glossy fine body mixed on at least the surface layer side of the base material and adjusting the color tone of the surface layer of the base material A resin molded article characterized in that a plate-like body having a component is included as a glossy fine body.

The resin molded article in the above-mentioned or claim 1 is a bumper.

[0037]

According to the resin molded product of the present invention, since the glossy minute body is constituted by a three-dimensionally curved plate-like body, a two-dimensional simple disk-like glossy minute body is obtained. Compared with the case of using, it is more advantageous to suppress the gloss microscopic body from being oriented in a specific direction due to the influence of the resin flow. Therefore, unevenness in color tone in the appearance of the resin molded product can be reduced, and the appearance quality can be improved.

The resin molded product according to the present invention, which can reduce color tone unevenness, is advantageous in reducing color tone unevenness while reducing the blending amount of glossy fine particles. Therefore, it is advantageous to reduce the consumption of the glossy fine body, and the price can be reduced.
Further, it can contribute to securing the strength of the resin molded product. Further, a transparent coating film may be laminated on the surface of the resin molded product in order to further improve the design. In this case, according to the resin molded product of the present invention, the color tone unevenness of the appearance of the resin molded product can be reduced, which is advantageous for simplifying or eliminating the coating film.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram schematically showing a cross section near a surface layer of a resin molded product.

FIG. 2 is a partial sectional view of a molding die.

FIG. 3 is a partial cross-sectional view of a state where a resin molded product is molded by a molding die.

FIG. 4 is a conceptual perspective view showing an example of a glossy fine body.

FIG. 5 is a conceptual perspective view showing another example of a glossy fine body.

FIG. 6 is a conceptual perspective view showing still another example of a glossy fine body.

FIG. 7 is a perspective view according to an application example.

FIG. 8 is a conceptual diagram schematically showing a cross section of a resin molded product according to the prior art.

[Explanation of symbols]

 In the figure, 1 is a substrate, 3 is a glossy fine body, and 5 is a mold.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toko Nobuhiko 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Keita Nagano 3-6-8 Kutaro-cho, Chuo-ku, Osaka-shi Toyo Aluminum Co., Ltd. (72) Inventor Isamu Yamaguchi 1-7-6, Nihonbashi Bakurocho, Chuo-ku, Tokyo Dainichi Seika Industry Co., Ltd. F-term (reference) 4F070 AA13 AA15 AA18 AA22 AA42 AA47 AA54 AA55 AC06 AC07 AC27 AD01 AD10 AE04 FA01 4F100 AA37A AB10A AC10A AD11A AK01A AK07A AN00A BA01 BA43 CA13A DE01A EH36 GB32 JN21A JN24 4F206 AA11 AA45 AB12 AB18 AB25 AB26 AB27 AC04 AG03 AH24 JA07 JF02 4F207 AA11 AB04 AB12 AB12 AB12 AB13 AB12 CB001 CC031 CD001 CF001 CL001 CM041 DA036 DA078 DA088 DA098 DA108 DC008 DE107 DE116 DE237 DG027 DG047 F A018 FD096 GM00 GN00

Claims (1)

[Claims] 1. A resin molded article comprising: a base material mainly composed of a resin; and a glossy fine body mixed on at least a surface layer side of the base material and adjusting a color tone of a surface layer of the base material. A resin molded article characterized in that the body is constituted by a plate-like body having a bent portion three-dimensionally bent.