JPH11130966A - Heat-ray-nonabsorbent coloring composition containing metal semiconductor powder and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat-ray-nonabsorbent coloring compsn. which enables a molded article to be colored black or deeply and to be heat-ray-nonabsorbent by incorporating a metal semiconductor powder such as a silicon powder into the same. SOLUTION: This coloring compsn. contains a metal semiconductor powder as a pigment. Powders of silicon, germanium, gallium-arsenic, gallium-aluminum- arsenic, etc., are listed as the metal semiconductor powders. Light with energy higher than the band gap, 0.8-1.5 eV, of these metal semiconductors is completely absorbed, though light with a lower energy is not absorbed. Silicon, having a band gap of 1.1 eV, does not absorb light with a wavelength corresponding to the band gap, i.e., 1100 nm, or higher while absorbing visible light only and hence looks black. The reflectance of heat rays can be increased by increasing the amt. of metal semiconductor particles compounded, and the transmittance of heat rays can be increased by decreasing the particle size and film thickness. The coloring compsn. can be used in resin compsns., coating compsns., oil or fat compsns., etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat ray non-absorbing colored composition, a molded article composed of the colored composition, and a molded article having a layer composed of the colored composition. The present invention relates to a colored composition which is colored and has a non-heat ray absorbing property despite being colored, a molded article composed of the colored composition, and a molded article having a layer composed of the colored composition. .

[0002]

2. Description of the Related Art While a white film has a high reflectance of visible light and infrared light, a colored film or a black colored film absorbs infrared light (heat ray) together with visible light. For this reason, there is a problem that, for example, when an object having a black film is exposed to sunlight, the object is heated to a higher temperature than an object having a white film, and the object temperature rises.

Conventionally, most of black paint, black resin and the like use fine particles such as carbon black dispersed therein. Carbon black absorbs light in the entire visible light range and therefore exhibits a very good black color. However, carbon black absorbs light well in the infrared region. Of the light from the sun, the infrared region, particularly the near infrared region (1000
(2500 nm) is a heat ray, and carbon black easily absorbs this heat ray and easily generates heat.

For example, when a black film is used for a surface exposed to sunlight such as an exterior material or a roof, for example, carbon black generates heat, and the coating absorbs the heat, thereby heating the coating material. Therefore, there was a problem that the inside of the building was also heated. As a countermeasure, a method of incorporating a metal oxide pigment such as manganese oxide, cobalt oxide, iron oxide, or chromium oxide that reflects infrared rays into a paint or a colored resin has been implemented. However, these pigments do not
Although it does not absorb heat rays as much as Bon Black, it has not less absorption bands not only in the visible light region but also in the infrared region. Therefore, pigments, paints and resin compositions which do not absorb heat rays have been desired.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a method for coloring black or colored. An object of the present invention is to provide a colored composition which is non-heat ray-absorbing, a molded article composed of the colored composition, and a molded article having a layer composed of the colored composition.

[0006]

Means for Solving the Problems As a result of diligent studies on the above-mentioned problems, the present inventors have found that when metal semiconductor fine particles are added as a pigment, they are black and colored, but not heat ray-absorbing. It has been found that a composition that is capable of reflecting or transmitting heat rays can be obtained by adjusting the composition and the like, and the present invention has been completed.

That is, the heat ray non-absorbing coloring composition of the present invention is characterized by containing a metal semiconductor fine powder. Furthermore, the molded article of the present invention is a molded article characterized by being constituted by the above-mentioned colored composition, or a molded article characterized by having a layer constituted by the above-mentioned colored composition. Further, the heat ray non-absorbing coloring composition of the present invention is a heat ray reflecting coloring composition or a heat ray transmitting coloring composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the fine metal semiconductor powder that can be used in the present invention include silicon, germanium, gallium / arsenic, and gallium / aluminum / arsenic. These are semiconductors having a band gap in the range of 0.8 to 1.5 eV. When these metal semiconductor fine powders are used, light having an energy larger than their band gap is completely absorbed, but light having an energy smaller than their band gap is not absorbed. In the present invention, for example, when using a silicon fine powder as the metal semiconductor fine powder,
The band gap of silicon is 1.1 eV, which corresponds to a wavelength of 1100 nm. Therefore, light having a wavelength shorter than 1100 nm is almost completely absorbed, but 1100 nm
Light having a wavelength longer than nm is not absorbed. That is, light in the visible light region is completely absorbed and exhibits good black color, but infrared light is not absorbed.

Metal semiconductors include single crystal powders and polycrystalline powders, but the present invention utilizes the essential physical properties of metal semiconductors, and their production method and shape are not limited. But,
Large-grain metal semiconductors and flake metal semiconductors have metallic luster and have poor dispersibility in resins, oils, paint compositions, etc. It is difficult. However, fine particles, preferably fine particles having an average particle diameter of 100 μm or less, have good dispersibility in resins, oils and fats, coating compositions and the like, and tend to improve blackness. It is desirable to use as. As the fine powder, a pulverized powder of a metal semiconductor or a semiconductor cutting residue can also be used. However, since gallium / arsenic fine powder is harmful to humans, it is generally desirable to use silicon fine powder. Even if the metal semiconductor contains an impurity, for example, a dopant such as phosphorus, there is almost no difference in heat ray non-absorption and heat ray reflection efficiency.

By incorporating these metal semiconductor fine powders into resins, paints, oils and fats (cosmetics, etc.), and in particular into coating compositions such as black paints, black resins and black films, it is possible to obtain the conventional The absorption of heat rays can be extremely reduced as compared with the black coating composition. Also,
In addition to the black type, the composition can be changed from a gray type to a black type or various chromatic colors by mixing other various color pigments with the metal semiconductor fine particles.

In the coloring composition of the present invention, the particle size of the metal semiconductor fine particles in the composition, the mixing ratio with the resin, the paint or the oil and the like are changed, or the thickness of the film formed by the coloring composition is changed. By changing the value, it is possible to control the reflection of heat rays by the molded article and the degree of the heat rays passing through the molded article.

For example, when the blending amount of the metal semiconductor fine particles is increased, the reflectance of the heat ray is increased, and the transmittance of the heat ray can be increased by reducing the particle diameter and the thickness of the film. . When silicon fine particles are used, the particle diameter is 100 μm or less, preferably 50 μm.
If it is less than m, it is possible to form a film having heat ray permeability by dispersing well with a resin, oil or the like. Examples of the coloring composition of the present invention include a resin composition, a coating composition, a fat composition (such as cosmetics), and the like, but the raw materials, components, and compositions of each composition are not particularly limited.

The coloring composition of the present invention can reflect or transmit heat rays by changing the particle size of the metal semiconductor fine particles as described above. Can be cited. As a first mode of use, there is a case where a coating of the coloring composition of the present invention is applied to the surface of a material such as metal, resin, wood, and porcelain in order to suppress the material from being heated. In this case, the coating should not absorb heat rays but reflect at the coating surface. As a second mode of use, there is a case where a film of the coloring composition of the present invention is formed on a transparent material such as glass or a resin film. In this case, the coating should transmit heat rays without absorbing them.

In the molded article having the heat ray non-absorbing layer constituted according to the above-mentioned use form, the entire molded article may be constituted by the coloring composition of the present invention, or only the surface layer of the molded article may be constituted. It may be composed of the coloring composition of the present invention and the inside thereof may be composed of a composition other than the present invention. Furthermore, a protective film may be provided on those surfaces.

[0015] Black coatings and resin molded products have a design property and are aesthetically pleasing, so they are widely used, but have the drawback that they tend to become hot when they absorb sunlight and the like. The disadvantages can be overcome by using the coloring composition of the invention. Therefore, the coloring composition of the present invention can be widely used for, for example, building exteriors, roofs, light-shielding materials, window glasses, shutters, vehicle exterior coatings, vehicle interior materials, and the like. Further, the coloring composition of the present invention can form a film or the like that is less likely to absorb heat from sunlight or the like even in colors other than black.

[0016]

【Example】

Example 1 ₅₀ g of silicon fine powder (average particle size D _50% = 5.8 μm) recovered from silicon semiconductor cutting oil and acrylic silica
A black paint (Munsell symbol: approx. 5YR2 / 1) was prepared by mixing well with 100 g of a clear paint. This was applied to a metal plate with a brush and dried for one day.

Visible-near infrared spectrophotometer (manufactured by Hitachi, Ltd .:
U-4000), and the reflection spectrum of this coated metal plate was measured using an integrating sphere. As a result, as shown in FIG. 1, it was confirmed that visible light (400 nm to 800 nm) was well absorbed and a black color was observed. However, light having a wavelength of 1 μm or more was substantially uniform except for absorption by the coating film. It can be seen that the light is reflected. The wavelength of light called heat rays is mainly 1 μm
As described above, it was confirmed that the paint reflects these lights. The solar reflectance of this film (JISR 31
06 (1985), the solar reflectance was 24.0%.

COMPARATIVE EXAMPLE 1 100 g of an acrylic silicate-based clear coating material was added to 3.
8 g, 2.6 g of graphite, 2 g of titanium oxide, 7 g of calcium carbonate and 2 g of carbon black were added to prepare a paint of the same color as in Example 1. This was brush-coated on a metal plate and dried. The visible-near infrared reflection spectrum of this film was measured. As a result, as shown in FIG. 1, the infrared ray region was absorbed as well as the visible light region, and the heat ray reflection was extremely low. The solar reflectance of this film was 7.4%.

Example 2 and Comparative Example 2 The paint prepared in Example 1 was applied to six outer surfaces of a 3 × 3 × 4 cm aluminum closed container with a lid to produce a black container. Install a thermometer in the center of this container,
4 on the ground where sunlight is directly radiated outdoors
The temperature rise was measured by exposing at an angle of 5 °. as a result,
Exposure was started at 9:00 in fine weather in the middle of July, and the temperature inside the container measured at 14:00 was 39 ° C.

On the other hand, the paint prepared in Comparative Example 1 was similarly applied to the outer surface of an aluminum container to produce a black container. When this was exposed to sunlight under the same conditions as in Example 2, the temperature inside the container was 44 ° C., and the temperature inside the container was 5 ° C. higher than in Example 2.

Example 3 A coating was prepared by mixing 8.5 g of the silicon fine powder and 8.5 g of titanium oxide used in Example 1 with 100 g of an acrylic silicate-based coating. The paint was applied to a metal plate and dried to obtain a gray (Munsell symbol: N-5.5) film. The visible-near infrared spectral reflection spectrum of this film was measured to obtain the results shown in FIG. The solar reflectance is 39.
7%.

Comparative Example 3 Titanium oxide 16 was added to 100 g of an acrylic silicate paint.
g, red iron oxide 0.1 g, graphite 0.3 g and carbon black 0.3 g were added and mixed to prepare a paint. This paint is applied to a metal plate and dried to give a grayish (Munsell symbol: N-
6) A film was prepared. The visible-near infrared spectral reflection spectrum of this film was measured to obtain the results shown in FIG. The solar reflectance was 27.1%, which was lower than the value of Example 3.

Example 4 and Comparative Example 4 18 g of the silicon fine powder used in Example 1 and phthalocyanine rubble were added to 100 g of an acrylic silicate paint.
3 g were mixed to prepare a paint. This was applied to a metal plate and dried to obtain a black (Munsell symbol: N-2) film. The visible-near infrared spectral reflection spectrum of this film was measured to obtain the results shown in FIG. The solar reflectance is 20.
9%.

On the other hand, 100 g of an acrylic silicate paint
Was mixed with 20 g of carbon black to prepare a paint. This was applied to a metal plate and dried to form a black film of the same color as in Example 4. The visible-near infrared spectral reflection spectrum of this film was measured to obtain the results shown in FIG. The solar reflectance was 4.1%. As is clear from these results, it is understood that the paint containing the silicon fine powder is a very good heat ray reflective coating as a black paint.

Example 5 and Comparative Example 5 A paint was prepared by mixing 7 g of dichromium trioxide and 8 g of the fine silicon powder used in Example 1 with 100 g of an acrylic silicate paint. The paint was applied to a metal plate and dried to obtain a dark green (Munsell symbol: approx. 2.5G3 / 4) film. The visible-near infrared reflection spectrum of this film was measured to obtain the results shown in FIG.

For comparison, acrylic silicate paint 1
Then, 7 g of dichromium trioxide and 1.5 g of carbon black were mixed with 00 g to prepare a paint having substantially the same color as in Example 5. This coating material was applied to a metal plate and dried, and the visible-near infrared reflection spectrum of the film obtained was measured to obtain the results shown in FIG.

As is apparent from the comparison of these spectra, it was confirmed that the reflectance in the near infrared region was extremely different while exhibiting almost the same color. From these results, it was confirmed that the paint according to the present invention exhibited an extremely high effect as a heat ray reflective paint having a chromatic color, particularly a dark chromatic color which was conventionally toned with carbon black.

Examples 6 to 7 and Comparative Example 6 1.9 g of the silicon fine powder used in Example 1 was added to 38 g of ethylene-ethyl acrylate resin (Nippon Petrochemical Lexlon EEA) (addition ratio: 5.0 wt. %) And 19
After kneading at 0 ° C., a film was formed by a film forming machine (Example 6). The thickness of this film is about 200μ
m, the color was brown and almost opaque visually.

Further, 0.57 g of silicon fine powder was added to 38 g of ethylene-ethyl acrylate resin (Nippon Petrochemical Lexlon EEA) (addition ratio: 1.5% by weight).
Then, a film was formed in the same manner (Example 7). The thickness of this film was about 170 μm, and was visually translucent.

The visible-near-infrared spectral transmission spectrum of these films was measured. As shown in FIG. 5, light was almost absorbed in the visible light region, but light in the near-infrared region was almost the same except for absorption by the resin. It was confirmed that the light was uniformly transmitted. For comparison, 0.04 g of carbon black was added in place of the silicon fine powder, and an almost opaque black resin film was similarly produced (Comparative Example 6). The visible-near infrared spectral transmission spectrum of this film is also shown in FIG. It can be seen that addition of carbon black almost completely absorbs light in the visible light region and almost absorbs light in the near-infrared region even in a minute amount.

From these results, it can be seen that the metal semiconductor-containing film obtained from the resin composition of the present invention is translucent or almost opaque in the visible light region as compared with the conventional black film using carbon black. Also, it was confirmed that the film had high near-infrared transmittance and was effective as a film that did not absorb heat rays.

Example 8 and Comparative Example 7 1.9 g of the silicon fine powder used in Example 1 was added to 38 g of polyethylene (addition ratio: 5.0% by weight), kneaded at 190 ° C., and injection molded. A brown resin molded product having a thickness of about 3 mm was obtained. As a result of measuring the visible-near infrared reflection spectrum of the surface of the resin molded product, the result was as shown in FIG.

On the other hand, for comparison, carbon black (0.04 g) was added instead of silicon fine powder,
And then injection molded to obtain a black resin molded product having a thickness of about 3 mm. As shown in FIG. 6, the visible-near-infrared reflection spectrum of the surface of the resin molded product is almost completely absorbed from visible light to near-infrared light. From these results, compared with the conventional black resin molded product using carbon black, the resin molded product containing the metal semiconductor absorbs light in the visible light region but has a high reflectance of near-infrared rays, and the heat ray reflective resin molded product is used. The product was confirmed to be effective.

[0034]

As described above, the heat ray non-absorbable coloring composition of the present invention, a molded article composed of the coloring composition, and a molded article having a layer composed of the coloring composition The layer composition can be colored in various ways and does not absorb heat rays, so that it can be used for various applications.

[Brief description of the drawings]

FIG. 1 is a view showing a visible-near-infrared spectral reflection spectrum of a metal plate with a black coating film obtained in Example 1 and Comparative Example 1.

FIG. 2 is a view showing a visible-near-infrared spectral reflection spectrum of a metal plate with a gray coating film obtained in Example 3 and Comparative Example 3.

FIG. 3 is a view showing a visible-near-infrared spectral reflection spectrum of the metal plate with a black coating film obtained in Example 4 and Comparative Example 4.

FIG. 4 is a view showing a visible-near-infrared spectral reflection spectrum of the dark green coating film obtained in Example 5 and Comparative Example 5.

FIG. 5 is a view showing the visible-near-infrared spectral transmission spectra of the black resin films obtained in Examples 6, 7 and Comparative Example 6.

FIG. 6 is a view showing a visible-near-infrared spectral reflection spectrum of the black resin obtained in Example 8 and Comparative Example 7.

Claims (10)

[Claims] 1. A heat ray non-absorbing colored composition comprising a metal semiconductor fine powder. 2. The coloring composition according to claim 1, wherein the heat ray non-absorbing coloring composition is a heat ray reflecting coloring composition. 3. The coloring composition according to claim 1, wherein the heat ray non-absorbing coloring composition is a heat ray transmitting coloring composition. 4. The coloring composition according to claim 1, wherein the metal semiconductor fine powder is a silicon fine powder. 5. The colored composition according to claim 1, wherein the metal semiconductor powder has an average particle size of 100 μm or less. 6. The coloring composition according to claim 1, further comprising another pigment together with the metal semiconductor fine powder. 7. The coloring composition according to claim 1, wherein the heat ray non-absorbing coloring composition is a coloring resin composition. 8. The coloring composition according to claim 1, wherein the heat ray non-absorbing coloring composition is a coloring coating composition. 9. A molded article comprising the coloring composition according to claim 7. 10. A molded article having a layer composed of the coloring composition according to claim 7 or 8.