Resin molded article

Abstract

Provided is a resin molded article that can be thermally decomposed with less labor, time, and cost. This resin molded article contains a resin, anatase titania, and a light blocking agent that reduces the amount of light having a frequency of from 3 THz to 30 PHz with which the anatase titania is irradiated. The resin molded article has a resin substrate (1) containing a resin, an anatase layer (2) containing anatase titania, and a light blocking layer (3) containing a light blocking agent, and has a laminated structure in which the anatase layer (2) is disposed between the surface of the resin substrate (1) and the light blocking layer (3).

Description

Resin molded product

[0001] The present invention relates to a resin molded product.

[0002] Recycling of used automobiles is being carried out, and among the automobile shredder residues generated from used automobiles, waste resin is subjected to pyrolysis treatment. Patent Document 1 discloses a technique for pyrolyzing waste resin by adding rutile-type titania to the waste resin and heating it.

[0003] International Publication No. 2014 / 125995

[0004] However, in the technique disclosed in Patent Document 1, since a step of adding rutile-type titania to the waste resin is required during the pyrolysis treatment, there is a risk that the labor, time, and cost required for the pyrolysis treatment will increase. An object of the present invention is to provide a resin molded product that can be pyrolyzed with less labor, time, and cost.

[0005] The resin molded product according to one aspect of the present invention mainly contains a resin, anatase-type titania, and a light blocking agent that reduces the amount of light having a frequency of 3 THz or more and 30 PHz or less irradiated to the anatase-type titania.

[0006] According to the present invention, a resin molded product that can be pyrolyzed with less labor, time, and cost can be provided.

[0007] It is a schematic cross-sectional view showing the structure of a resin molded product according to the first embodiment of the present invention. It is a schematic cross-sectional view showing the structure of a resin molded product according to the second embodiment of the present invention. It is a schematic cross-sectional view showing the structure of a resin molded product according to the third embodiment of the present invention. It is a schematic cross-sectional view showing the structure of a resin molded product according to the fourth embodiment of the present invention.

[0008] One embodiment of the present invention will be described below. Note that this embodiment shows an example of the present invention, and the present invention is not limited to this embodiment. In addition, various changes or improvements can be made to this embodiment, and forms with such changes or improvements can also be included in the present invention.

[0009] The resin molded product according to this embodiment contains a resin, anatase-type titania, and a light-blocking agent that reduces the amount of light with a frequency of 3 THz to 30 PHz irradiated onto the anatase-type titania. Since the resin molded product according to this embodiment contains anatase-type titania, the step of adding titania is unnecessary when the resin molded product is subjected to thermal decomposition treatment. Conventionally, for example, a method was used in which the resin molded product was crushed, titania was mixed in, and then heated to thermally decompose the resin, but if the resin molded product contains anatase-type titania, it is not necessary to add titania when performing thermal decomposition treatment. Since the resin molded product according to this embodiment does not require the step of adding titania, thermal decomposition treatment can be performed with less effort, time, and cost.

[0010] Furthermore, conventionally, rutile-type titania was added and heated to perform thermal decomposition of the resin, resulting in a large amount of carbon dioxide being emitted during the thermal decomposition of the resin. In contrast, since the resin molded product according to this embodiment contains anatase-type titania, heating using light with a frequency of 3 MHz to 30 GHz (for example, microwaves (light with a frequency of 300 MHz to 2450 MHz)) is possible, resulting in the effect of relatively low carbon dioxide emissions during the thermal decomposition of the resin. This effect will be explained in detail below.

[0011] Rutile titania does not react to light with a frequency of 3 MHz to 30 GHz, but anatase titania reacts to light with a frequency of 3 MHz to 30 GHz, transforming into rutile titania and generating heat. This heat can then be used to thermally decompose the resin. For example, if a resin molded product according to this embodiment is irradiated with microwaves, the resin in the molded product will be thermally decomposed due to the heat generated by the transformation of anatase titania to rutile titania. When a resin is thermally decomposed by heat generated by irradiation with light with a frequency of 3 MHz to 30 GHz, the amount of carbon dioxide emitted during thermal decomposition is relatively small compared to when the resin is thermally decomposed by simple heating. Therefore, by irradiating a resin molded product according to this embodiment with light with a frequency of 3 MHz to 30 GHz, thermal decomposition can be performed with a small amount of carbon dioxide emissions.

[0012] However, anatase titania is photoactive and has a photocatalytic effect that decomposes resins in response to light with a frequency of 3 THz to 30 Hz. For example, when a mixture of resin and anatase titania is irradiated with ultraviolet light (light with a frequency of 750 THz to 30 Hz), the resin present in the vicinity of the anatase titania is decomposed by the photocatalytic effect of the anatase titania.

[0013] However, since the resin molded product according to this embodiment contains a light-blocking agent that reduces the amount of light with a frequency of 3 THz to 30 Hz irradiated onto the anatase-type titania, even if light with a frequency of 3 THz to 30 Hz irradiated onto the anatase-type titania is reduced. As a result, the photocatalytic effect of anatase-type titania is less likely to occur, and even if the resin molded product according to this embodiment is irradiated with light with a frequency of 3 THz to 30 Hz, decomposition of the resin due to the photocatalytic effect of anatase-type titania is less likely to occur. Therefore, even if the resin molded product according to this embodiment is irradiated with light with a frequency of 3 THz to 30 Hz, performance degradation such as a decrease in strength is less likely to occur.

[0014] Examples of resin molded articles according to this embodiment (first to fourth embodiments) will be described with reference to Figures 1 to 4. Figure 1 is a schematic cross-sectional view showing the structure of a resin molded article according to the first embodiment of the present invention. That is, the resin molded article according to the first embodiment has a resin substrate 1 containing resin, an anatase layer 2 containing anatase-type titania, and a light-blocking layer 3 containing a light-blocking agent, and has a laminated structure in which the anatase layer 2 is disposed between the surface of the resin substrate 1 and the light-blocking layer 3.

[0015] For example, the resin substrate 1 is a component formed from a resin material, the anatase layer 2 is a coating layer containing anatase-type titania, and the light-blocking layer 3 is a coating layer containing a light-blocking agent. The resin molded product according to the first embodiment has a laminated structure in which the anatase layer 2 is formed on the surface of the resin substrate 1, and the light-blocking layer 3 is formed on top of the anatase layer 2. In the resin molded product according to the first embodiment, other layers may be interposed between the resin substrate 1 and the anatase layer 2, or between the anatase layer 2 and the light-blocking layer 3, or both. Examples of other layers include adhesive layers that improve the adhesion between the upper and lower layers.

[0016] When the resin molded product according to the first embodiment is irradiated with light with a frequency of 3 MHz to 30 GHz, the anatase-type titania in the anatase layer 2 is converted to rutile-type titania and generates heat. This heat can cause thermal decomposition of the resin in the resin substrate 1. Furthermore, since the light-blocking layer 3 is formed on the anatase layer 2, even if the resin molded product according to the first embodiment is irradiated with light with a frequency of 3 THz to 30 PHz, the light-blocking layer 3 blocks the light with a frequency of 3 THz to 30 PHz, reducing the amount of light with a frequency of 3 THz to 30 PHz that reaches the anatase layer 2. Therefore, the photocatalytic effect of anatase-type titania is less likely to occur, and thus photocatalytic decomposition of the resin in the resin substrate 1 is less likely to occur.

[0017] In the resin molded product according to the first embodiment, the anatase layer 2 contains anatase-type titania, but the light-blocking layer 3 may also further contain anatase-type titania together with a light-blocking agent. The light-blocking layer 3 blocks light with a frequency of 3 THz to 30 Hz, and the amount of light with a frequency of 3 THz to 30 Hz reaching the anatase-type titania in the light-blocking layer 3 is reduced. Therefore, even if the resin molded product according to the first embodiment is irradiated with light with a frequency of 3 THz to 30 Hz, the photocatalytic effect of the anatase-type titania in the light-blocking layer 3 is unlikely to occur. Furthermore, since the anatase-type titania in the light-blocking layer 3 and the resin substrate 1 are not in contact, even if the photocatalytic effect of the anatase-type titania in the light-blocking layer 3 is expressed, decomposition of the resin in the resin substrate 1 due to the photocatalytic effect is unlikely to occur.

[0018] Figure 2 is a schematic cross-sectional view showing the structure of a resin molded product according to the second embodiment of the present invention. Specifically, the resin molded product according to the second embodiment comprises a resin substrate 1 containing resin, an anatase layer 2 containing anatase-type titania, a light-blocking layer 3 containing a light-blocking agent, and a surface layer 4 made of paint or coating agent. The anatase layer 2 is disposed between the surface of the resin substrate 1 and the light-blocking layer 3, and the surface layer 4 is disposed on the surface of the light-blocking layer 3 opposite to the surface facing the anatase layer 2, resulting in a laminated structure.

[0019] For example, the resin substrate 1 is a component formed from a resin material, the anatase layer 2 is a coating layer containing anatase-type titania, the light-blocking layer 3 is a coating layer containing a light-blocking agent, and the surface layer 4 is the outermost layer. The resin molded product according to the second embodiment has a laminated structure in which the anatase layer 2 is formed on the surface of the resin substrate 1, the light-blocking layer 3 is formed on the anatase layer 2, and the surface layer 4 is formed on the light-blocking layer 3.

[0020] In the resin molded product according to the second embodiment, at least one other layer may be interposed between the resin substrate 1 and the anatase layer 2, between the anatase layer 2 and the light-blocking layer 3, and between the light-blocking layer 3 and the surface layer 4. Examples of other layers include adhesive layers that improve the adhesion between the upper and lower layers.

[0021] The resin molded product according to the second embodiment has the same structure as the resin molded product according to the first embodiment, except that it has a surface layer 4, and therefore achieves the same effects as the resin molded product according to the first embodiment. Furthermore, because it has a surface layer 4, the resin molded product according to the second embodiment has excellent design, weather resistance, and durability.

[0022] In the resin molded product according to the second embodiment, the anatase layer 2 contains anatase-type titania, but the light-blocking layer 3 may also further contain anatase-type titania together with a light-blocking agent. The light-blocking layer 3 blocks light with a frequency of 3 THz to 30 Hz, and the amount of light with a frequency of 3 THz to 30 Hz reaching the anatase-type titania in the light-blocking layer 3 is reduced. Therefore, even if the resin molded product according to the second embodiment is irradiated with light with a frequency of 3 THz to 30 Hz, the photocatalytic effect of the anatase-type titania in the light-blocking layer 3 is unlikely to occur. Furthermore, since the anatase-type titania in the light-blocking layer 3 and the resin substrate 1 are not in contact, even if the photocatalytic effect of the anatase-type titania in the light-blocking layer 3 is expressed, decomposition of the resin in the resin substrate 1 due to the photocatalytic effect is unlikely to occur.

[0023] Figure 3 is a schematic cross-sectional view showing the structure of a resin molded product according to the third embodiment of the present invention. That is, the resin molded product according to the third embodiment has a resin substrate 1 containing resin and an anatase layer 5 containing core-shell type titania particles (not shown), and the anatase layer 5 is disposed on the resin substrate 1. The core-shell type titania particles in the anatase layer 5 are particles that have a core portion having anatase-type titania and a shell portion having a light-blocking agent and covering the core portion, thereby forming a core-shell structure.

[0024] For example, the resin substrate 1 is a component formed from a resin material, and the anatase layer 5 is a coating layer containing the core-shell type titania particles. The resin molded product according to the third embodiment has a structure in which the anatase layer 5 is formed on the surface of the resin substrate 1. In the resin molded product according to the third embodiment, other layers may be interposed between the resin substrate 1 and the anatase layer 5. Examples of other layers include adhesive layers that improve the adhesion between the upper and lower layers.

[0025] When the resin molded product according to the third embodiment is irradiated with light of a frequency of 3 MHz to 30 GHz, the anatase-type titania in the core-shell type titania particles in the anatase layer 5 is converted to rutile-type titania, generating heat. This heat can cause the resin in the resin substrate 1 to be thermally decomposed.

[0026] Furthermore, the core-shell type titania particles in the anatase layer 5 have a core-shell structure in which the core portion containing anatase-type titania is covered by a shell portion containing a light-blocking agent. Therefore, even if the resin molded product according to the third embodiment is irradiated with light of a frequency of 3 THz to 30 Hz, the shell portion blocks the light of a frequency of 3 THz to 30 Hz, reducing the amount of light of a frequency of 3 THz to 30 Hz that reaches the core. As a result, the photocatalytic effect of anatase-type titania is less likely to be expressed, and decomposition of the resin in the resin substrate 1 due to the photocatalytic effect is less likely to occur.

[0027] Figure 4 is a schematic cross-sectional view showing the structure of a resin molded article according to the fourth embodiment of the present invention. Specifically, the resin molded article according to the fourth embodiment comprises a resin substrate 1 containing resin, an anatase layer 5 containing core-shell type titania particles (not shown), and a surface layer 4 made of paint or coating agent. The anatase layer 5 is arranged on the resin substrate 1, and the surface layer 4 is arranged on the surface of the anatase layer 5 opposite to the surface facing the resin substrate 1, resulting in a laminated structure. The core-shell type titania particles in the anatase layer 5 are the same as those in the third embodiment.

[0028] For example, the resin substrate 1 is a component formed from a resin material, the anatase layer 5 is a coating layer containing the core-shell type titania particles, and the surface layer 4 is the outermost layer. The resin molded product according to the fourth embodiment has a laminated structure in which the anatase layer 5 is formed on the surface of the resin substrate 1, and the surface layer 4 is formed on top of the anatase layer 5. In the resin molded product according to the fourth embodiment, other layers may be interposed between the resin substrate 1 and the anatase layer 5, or between the anatase layer 5 and the surface layer 4, or both. Examples of other layers include adhesive layers that improve the adhesion between the upper and lower layers.

[0029] The resin molded product according to the fourth embodiment has the same structure as the resin molded product according to the third embodiment, except that it has a surface layer 4, and therefore achieves the same effects as the resin molded product according to the third embodiment. Furthermore, because it has a surface layer 4, the resin molded product according to the fourth embodiment has excellent design, weather resistance, and durability.

[0030] The resin molded product according to this embodiment will be described in more detail below. [Resin Substrate] The resin substrate is, for example, a component formed from a resin material containing resin, and may be formed from resin alone, or from a resin composition containing resin, reinforcing material, and additives. A resin substrate can be obtained by molding a resin material containing resin using a molding method such as melt molding or compression molding.

[0031] [Type of Resin] The type of resin contained in the resin substrate is not particularly limited; for example, both thermoplastic resins and thermosetting resins can be used. Specific examples of thermoplastic resins include polyethylene, polypropylene, polyethylene terephthalate, and ABS resin. These resins may be used individually or in combination of two or more. ABS resin is a copolymer of acrylonitrile, butadiene, and styrene.

[0032] When the resin of a resin substrate undergoes thermal decomposition, decomposition gases are generated. Examples of decomposition gases include carbon monoxide (CO), carbon dioxide (CO2), hydrogen gas (H2), and hydrocarbon gases. Therefore, the resin molded product according to this embodiment can be used as a raw material for producing hydrogen gas.

[0033] [Light-blocking layer] The light-blocking layer is a layer containing a light-blocking agent, which reduces the amount of light with a frequency of 3 THz to 30 MHz that is irradiated onto the anatase-type titania. For example, a light-blocking layer can be formed on a resin substrate by applying a paint containing a light-blocking agent to form a coating film. Examples of light with a frequency of 3 THz to 30 MHz include ultraviolet light, infrared light (far-infrared and near-infrared), and visible light.

[0034] If the amount of light with a frequency of 3 THz to 30 PHz that passes through the light-blocking layer is reduced, the mechanism by which the light-blocking layer blocks light with a frequency of 3 THz to 30 PHz is not particularly limited. Mechanisms for blocking light with a frequency of 3 THz to 30 PHz include, for example, reflection, scattering, and absorption of light with a frequency of 3 THz to 30 PHz by the light-blocking layer.

[0035] [Light Blocking Agent] The type of light blocking agent is not particularly limited as long as it can reduce the amount of light with a frequency of 3 THz to 30 PHz that is irradiated onto the anatase-type titania, but silica (SiO2) is an example.

[0036] [Anatase Layer] The anatase layer is a layer containing anatase-type titania. When irradiated with light of a frequency of 3 MHz to 30 GHz, the anatase-type titania is converted to rutile-type titania and generates heat. For example, the anatase layer may be formed on a resin substrate by attaching and fixing anatase-type titania to the surface of the resin substrate, or the anatase layer may be formed on a resin substrate by applying a paint containing anatase-type titania to form a coating film. The properties of the anatase-type titania can be, for example, powder or granules. Examples of light of a frequency of 3 MHz to 30 GHz include microwaves and short waves. Microwaves are light of a frequency of 300 MHz to 2450 MHz.

[0037] [Core-shell type titania particles] The anatase-type titania used in the resin molded product according to this embodiment may be a powder made of anatase-type titania, or it may be the core-shell type titania particles described above. An example of a light-blocking agent in the shell is silica. The shell may be formed of silica, or it may be formed of a mixture of silica and other components.

[0038] [Surface Layer] The surface layer consists of a paint or coating agent and is primarily the outermost layer provided on the resin molded product according to this embodiment. Examples of paints include paints containing pigments, dyes, etc. Examples of coating agents include glass coating agents containing glass and polymer coating agents containing polymers.

[0039] [Light Absorber] In the resin molded product according to this embodiment (for example, the resin molded product according to the first to fourth embodiments), the resin substrate may contain a light absorber that absorbs light with a frequency of 3 MHz to 30 GHz and generates heat. When the resin molded product according to this embodiment is irradiated with light with a frequency of 3 MHz to 30 GHz, the light absorber absorbs the light and generates heat, reaching a high temperature (for example, 400°C), thus promoting the thermal decomposition of the resin. Then, a dehydrogenation reaction proceeds at the interface between the light absorber and the resin, generating hydrogen gas, and carbon nanotubes grow with the light absorber as a nucleus.

[0040] The type of light absorber is not particularly limited as long as it absorbs light with a frequency of 3 MHz to 30 GHz and generates heat, but examples include metals, metal oxides, and carbon materials. Specific examples of metals include iron (Fe), aluminum (Al), nickel (Ni), cobalt (Co), and titanium (Ti). These metals may be used individually or in combination of two or more. When two or more metals are used in combination, they may be mixtures or alloys of those metals.

[0041] Specific examples of metal oxides include iron oxide (FeO, Fe2O3), aluminum oxide (Al2O3), nickel oxide (NiO), cobalt oxide (CoO, Co2O3), and titanium oxide (TiO2). These metal oxides may be used individually or in combination of two or more.

[0042] When two or more metal oxides are used in combination, they may be a mixture of the two or more metal oxides, or a composite oxide of the two or more metals. An example of a composite oxide of two or more metals is a composite oxide of iron and aluminum. Specific examples of carbon materials include activated carbon, graphene nanoplatelets, graphene, graphite, and carbon nanotubes. These carbon materials may be used individually or in combination of two or more.

[0043] [Use of the resin molded product] The use of the resin molded product according to this embodiment is not particularly limited. For example, it can be used as an automotive part and can be used for both exterior and interior automotive parts. A specific example of an exterior automotive part is a bumper.

[0044] In the first and second embodiments, a resin molded product in which anatase layer 2 containing anatase-type titania is formed on the surface of resin substrate 1 is exemplified. However, the resin substrate 1 may contain anatase-type titania. That is, the resin substrate 1 may be formed of a resin material containing anatase-type titania.

[0045] When the resin substrate 1 contains anatase-type titania, the resin molded product may or may not have anatase layer 2. When the resin molded product does not have anatase layer 2, the resin molded product according to the first embodiment has a configuration including resin substrate 1 and light-blocking layer 3, and the resin molded product according to the second embodiment has a configuration including resin substrate 1, light-blocking layer 3, and surface layer 4.

[0046] In the resin molded products according to the first and second embodiments, anatase layer 2 and light-blocking layer 3 are laminated as separate layers, but they may be an integral layer. That is, a layer containing both anatase-type titania and a light-blocking agent may be formed on the surface of resin substrate 1. Since this layer contains both anatase-type titania and a light-blocking agent, it functions as an anatase layer and also functions as a light-blocking layer at the same time.

[0047] Furthermore, in the third and fourth embodiments, a resin molded product in which anatase layer 5 containing core-shell type titania particles is formed on the surface of resin substrate 1 is exemplified. However, the resin substrate 1 may contain core-shell type titania particles. That is, the resin substrate 1 may be formed of a resin material containing core-shell type titania particles.

[0048] When the resin matrix 1 contains core-shell type titania particles, the resin molded product may or may not have the anatase layer 5. When the resin molded product does not have the anatase layer 5, the resin molded product according to the third embodiment is composed only of the resin matrix 1, and the resin molded product according to the fourth embodiment has a structure including the resin matrix 1 and the surface layer 4.

[0049] Examples and comparative examples are shown below to more specifically explain the present invention. [Example 1] Anatase type titania powder with an average particle size of 0.18 μm (Titanium Oxide JA-1 manufactured by Tayca Corporation), xylene, ethyl acetate, and n-butanol were mixed at a mass ratio of 2:1:1:1, and this mixture was sprayed onto the surface of a polypropylene resin matrix by spray coating. Then, xylene, ethyl acetate, and n-butanol were removed by drying to form an anatase layer composed of anatase type titania on the surface of the resin matrix. These operations were performed in a dark room. The ratio of the mass of anatase type titania adhering to the surface of the resin matrix to the mass of the resin matrix is 1:5.

[0050] Next, a base paint (Protouch Mono Coat manufactured by Rock Paint Co., Ltd.) was applied by spray coating to the resin matrix with the anatase layer formed thereon to form a base layer with a thickness of 10 to 40 μm on the anatase layer. Then, a clear paint was applied (clear coating) to the resin matrix with the base layer formed thereon to form a clear layer with a thickness of 20 to 35 μm on the base layer. Since this clear paint contains a component that reflects ultraviolet rays, the clear layer is a light shielding layer having ultraviolet blocking performance. In this way, the resin molded product of Example 1 was manufactured.

[0051] [Comparative Example 1] A paint (Paint SPM-180 manufactured by Nippon Paint Co., Ltd.) containing rutile type titania powder and not containing anatase type titania powder was sprayed onto the surface of a polypropylene resin matrix by spray coating. Then, the solvent was removed by drying to form a coating film containing rutile type titania on the surface of the resin matrix. These operations were performed in a dark room.

[0052] Next, a base coat (Protouch Monocoat manufactured by Rock Paint Co., Ltd.) was spray-coated onto a resin substrate that had a coating film containing rutile-type titania, forming a base layer with a thickness of 10 to 40 μm on top of the coating film containing rutile-type titania. Then, a clear coat was applied to the resin substrate with the base layer (clear coating), forming a clear layer with a thickness of 20 to 35 μm on top of the base layer. Since this clear coat contains a component that reflects ultraviolet light, the clear layer is a light-blocking layer with ultraviolet light blocking properties. In this way, the resin molded product of Comparative Example 1 was manufactured.

[0053] [Example 2] To a paint (paint SPM-180 manufactured by Nippon Paint Co., Ltd.) that does not contain anatase-type titania powder but contains rutile-type titania powder, anatase-type titania powder (titanium dioxide JA-1 manufactured by Teika Co., Ltd.) with an average particle size of 0.18 μm was added to obtain a paint containing both anatase-type titania powder and rutile-type titania powder. The content of anatase-type titania powder in the total titania powder contained in the paint was 20% by mass (i.e., the content of rutile-type titania powder was 80% by mass).

[0054] A coating containing anatase-type titania powder and rutile-type titania powder was spray-coated onto the surface of a polypropylene resin substrate. The solvent was then removed by drying, forming an anatase layer containing the anatase-type titania powder and rutile-type titania powder on the surface of the resin substrate. These operations were performed in a darkroom.

[0055] Next, a base coating (Protouch Monocoat manufactured by Rock Paint Co., Ltd.) was applied to the resin substrate on which the anatase layer had been formed by spray coating, forming a base layer with a thickness of 10 to 40 μm on top of the anatase layer containing anatase-type titania powder and rutile-type titania powder. Then, a clear coating was applied to the resin substrate on which the base layer had been formed (clear coating), forming a clear layer with a thickness of 20 to 35 μm on top of the base layer. Since this clear coating contains components that reflect ultraviolet rays, the clear layer is a light-blocking layer with ultraviolet light blocking properties. In this way, the resin molded product of Example 2 was manufactured.

[0056] [Examples 3, 4, and 5] Resin molded products of Examples 3, 4, and 5 were manufactured in the same manner as in Example 2, except that the content of anatase-type titania powder in the total titania powder contained in the paint was different. The content of anatase-type titania powder in the total titania powder contained in the paint was 40% by mass for Example 3, 60% by mass for Example 4, and 80% by mass for Example 5.

[0057] Next, the resin molded products of Examples 1 to 5 and Comparative Example 1 were each finely crushed, and the resulting crushed material was irradiated with microwaves (frequency 2450 MHz) at an output of 300 W for 120 seconds to perform thermal decomposition of the resin. After microwave irradiation, the temperature of the crushed material was measured, and the appearance of the crushed material was visually observed. The results are described below.

[0058] The temperature of the crushed material in Comparative Example 1 was 25°C, and there was no change in appearance. Since no heat was generated when the rutile-type titania powder was irradiated with microwaves, it is considered that no thermal decomposition of the resin occurred. The temperature of the crushed material in Example 2 was 80°C, and discoloration was observed on the surface of the crushed material. The temperature of the crushed material in Example 3 was 230°C, and the crushed material melted. The temperature of the crushed material in Example 4 was 270°C, and the crushed material melted. The temperature of the crushed material in Example 5 was 480°C, and the surface of the crushed material was charred, indicating thermal decomposition of the resin. The temperature of the crushed material in Example 1 was 500°C, and the resin had thermally decomposed and turned into a sooty substance.

[0059] When the anatase-type titania powder was irradiated with microwaves, heat was generated. The higher the proportion of anatase-type titania powder in the total titania powder, the higher the temperature of the crushed material after microwave irradiation. Furthermore, in the case of the crushed resin molded products in Examples 1 and 5, the resin underwent thermal decomposition.

[0060] [Example 10] A test was conducted to confirm the effect of the light absorber. High-density polyethylene powder and metallic iron powder were mixed in a mass ratio of 1:1. Anatase-type titania powder was not mixed. This mixed powder was irradiated with microwaves (frequency 2450 MHz) at an output of 1000 W for 5 minutes. As a result, the metallic iron, which is the light absorber, absorbed the microwaves and generated heat, causing the high-density polyethylene to thermally decompose, and 0.24 L of hydrogen gas was generated per gram of high-density polyethylene.

[0061] [Example 11] An experiment was conducted in the same manner as in Example 10, except that iron oxide (FeO) was used as the light absorber, to confirm the effect of the light absorber. As a result, the iron oxide, which is the light absorber, absorbed microwaves and generated heat, causing the high-density polyethylene to decompose thermally, and 1.26 L of hydrogen gas was generated per gram of high-density polyethylene.

[0062] [Example 12] An experiment was conducted in the same manner as in Example 10, except that activated carbon was used as the light absorber, to confirm the effect of the light absorber. As a result, the activated carbon, which is the light absorber, absorbed microwaves and generated heat, causing the high-density polyethylene to decompose thermally, and 0.24 L of hydrogen gas was generated per gram of high-density polyethylene.

[0063] 1... Resin substrate 2... Anatase layer 3... Light-blocking layer 4... Surface layer 5... Anatase layer

Claims

1. A resin molded product containing a resin, anatase-type titania, and a light-blocking agent that reduces the amount of light with a frequency of 3 THz to 30 PHz irradiated onto the anatase-type titania.

2. The resin molded article according to claim 1, having a laminated structure comprising a resin substrate containing the resin, an anatase layer containing the anatase-type titania, and a light-blocking layer containing the light-blocking agent, wherein the anatase layer is disposed between the surface of the resin substrate and the light-blocking layer.

3. The resin molded article according to claim 2, further comprising a surface layer made of paint or a coating agent on the surface of the light-blocking layer opposite to the surface facing the anatase layer.

4. The resin molded article according to claim 2, wherein the light-blocking layer further contains anatase-type titania.

5. The resin molded article according to claim 1, comprising a resin substrate containing the resin and an anatase layer containing core-shell type titania particles, wherein the anatase layer is disposed on the resin substrate, and the core-shell type titania particles are particles having a core portion containing the anatase-type titania and a shell portion having the light-blocking agent and covering the core portion, thereby forming a core-shell structure.

6. The resin molded article according to claim 5, further comprising a surface layer made of paint or a coating agent on the surface of the anatase layer opposite to the surface facing the resin substrate.

7. The resin molded article according to any one of claims 1 to 6, wherein the resin is at least one of polyethylene, polypropylene, polyethylene terephthalate, and ABS resin.

8. The resin molded article according to any one of claims 1 to 6, wherein the resin substrate contains a light absorber that absorbs light with a frequency of 3 MHz or more and 30 GHz or less and generates heat.

9. The resin molded article according to claim 8, wherein the light absorber is at least one of iron, aluminum, nickel, cobalt, and titanium.

10. The resin molded article according to claim 8, wherein the light absorber is an oxide of at least one of iron, aluminum, nickel, cobalt, and titanium.

11. The resin molded article according to claim 8, wherein the light absorber is at least one of activated carbon, graphene nanoplatelets, graphene, graphite, and carbon nanotubes.

12. A resin molded article according to any one of claims 1 to 6, which is an automobile part.

13. A resin molded article according to any one of claims 1 to 6, which is an exterior part for an automobile or an interior part for an automobile.

Images