JP2003042841A - Infrared sensor cover and infrared sensor unit using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared sensor cover in which the number of laminations of high-refractive-index substance layers and low-refractive-index substance layers constituting a mirror coating layer is suppressed to be small, and which can display the decorative function of the mirror coating layer in addition to the intrinsic protective function of the cover, and to provide an infrared sensor unit. SOLUTION: The infrared sensor cover comprises a black synthetic-resin layer 1 through which infrared rays can be transmitted, and the mirror coating layer 2 which is formed partially on one face of the layer 1 and in which the high-refractive-index substance layers and the low-refractive-index substance layers are laminated. Its infrared transmissivity in a state that the layer 1 and the layer 2 are laminated is 70% or more. The infrared sensor unit is provided with the infrared sensor cover constituted in this manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared sensor cover which is arranged in front of an infrared sensor and has a function of concealing and protecting the infrared sensor and a decorative function, and an infrared sensor unit equipped with the infrared sensor cover. The present invention relates to an infrared sensor cover suitable for use as a vehicle-to-vehicle distance detection sensor and the like, and an infrared sensor unit using the same.

[0002]

2. Description of the Related Art As described above, when an infrared sensor cover is used to cover an inter-vehicle distance detection sensor mounted on a synthetic resin radiator grill of an automobile, for example, it is an important point in determining a vehicle design. Since the surface of the radiator grille is given a metallic glitter color to give a feeling of high quality, a mirror coat treatment is applied to the surface of the cover in order not to significantly deteriorate the design of the radiator grille as a whole. It is considered to be applied.

[0003]

However, if the mirror coat is made to satisfy the two functions of the function of transmitting infrared rays while protecting the infrared sensor and the function of absorbing visible light and concealing the infrared sensor, it becomes It is necessary to increase the number of layers of two types of thin films, a thin film of a refractive index material and a thin film of a low refractive index material, and as a black base material that transmits infrared rays, a plastic material having a linear expansion coefficient different from that of an inorganic mirror coat layer is used. When using such a synthetic resin,
There is a problem that cracks may occur during mirror coat processing and during use, and not only the function as a decorative item but also the original function as a cover may be impaired. Was becoming.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, in which the number of high refractive index substance layers and low refractive index substance layers constituting a mirror coat layer is suppressed to a small number,
An object of the present invention is to provide an infrared sensor cover capable of exhibiting a decorative function of a mirror coat in addition to the original protective function of the cover, and an infrared sensor unit using the infrared sensor cover.

[0005]

An infrared sensor cover according to claim 1 of the present invention comprises a black synthetic resin layer capable of transmitting infrared rays and a high refractive index partially formed on one surface of the black synthetic resin layer. The infrared ray transmissivity in the state where the black synthetic resin layer and the mirror coat layer are laminated is 70% or more, including the mirror coat layer in which the material layers and the low refractive index material layers are alternately laminated one by one or alternately. It is characterized by having a certain configuration, and the infrared sensor cover of this configuration is a means for solving the above-mentioned conventional problems.

An infrared sensor cover according to claim 2 of the present invention is a black synthetic resin layer through which infrared rays can pass, and a high refractive index substance layer and a low refractive index substance layer formed on one entire surface of the black synthetic resin layer. A mirror coat layer in which layers are alternately laminated one by one or alternately by a plurality of layers, and visible light partially formed on the mirror coat surface of this mirror coat layer is absorbed in a part of wavelength range and infrared rays are absorbed. A black synthetic resin layer including a color material layer containing at least one kind of permeable color material;
It is characterized in that the infrared transmittance in the state where the mirror coat layer and the color material layer are laminated is 70% or more, and the infrared sensor cover having this structure is used as a means for solving the above-mentioned conventional problems. .

The infrared sensor cover according to claim 3 of the present invention is constructed by laminating a protective layer containing a protective material capable of transmitting visible light and infrared rays, and the infrared sensor cover according to claim 4 of the present invention is The colorant layer comprises a UV absorber having an absorption spectrum in the UV wavelength range and capable of transmitting visible rays and infrared rays. The infrared sensor cover according to claim 5 of the present invention has a protective layer as a protective layer. ,
It is configured to include an ultraviolet absorber having an absorption spectrum in the ultraviolet wavelength range and capable of transmitting visible rays and infrared rays.

On the other hand, an infrared sensor unit using the infrared sensor cover according to claim 6 of the present invention is characterized by including the infrared sensor cover according to any one of claims 1 to 5. .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The infrared sensor cover of the present invention will be described in detail below. In addition, in this specification, "%" shows a mass percentage unless otherwise specified.

The infrared sensor cover according to the present invention is
Laminated black synthetic resin layer and mirror coat layer,
For example, an infrared sensor cover as shown in FIGS. 1 and 2 can be used. A protective layer 3 is laminated on these infrared sensor covers in addition to the black synthetic resin layer 1 and the mirror coat layer 2, and a color material layer 4 is also laminated on the infrared sensor covers shown in FIG. There is.

Here, the black synthetic resin layer 1 contains a transparent base material through which infrared rays can pass, and examples of the transparent base material include polymethyl (meth) acrylate, polyethyl (meth) acrylate, and polybutyl. Acrylic resins such as homopolymers or copolymers of (meth) acrylic acid esters such as (meth) acrylate, methyl (meth) acrylate / butyl (meth) acrylate copolymer, polyethylene terephthalate, polybutylene terephthalate, ethylene terephthalate / iso Thermoplastic polyester resin such as phthalate copolymer, polyethylene, polypropylene, polyolefin resin such as olefinic thermoplastic elastomer, polyvinyl fluoride, polyvinylidene fluoride,
Fluorine resins such as polytetrafluoroethylene and ethylene / tetrafluoroethylene copolymer, vinyl resins such as polyvinyl chloride and polyvinyl acetate, carbonate resins such as polycarbonate, polyether resins and polyurethane resins can be used. In addition, these can be used alone,
It is also possible to use two or more types in an arbitrary combination.

In order to make the transparent base material black, a dye having a wavelength of 750 nm to 1000 nm and having transparency is used as the synthetic resin. For example, azo dyes, anthraquinone dyes, naphthol dyes, and polymethine dyes can be used. These can also be used alone or in any combination of two or more, and the compounding amount is such that the visible light transmittance of the synthetic resin is 0 to 0 when the thickness is used as a cover. The content is 40%, more preferably 0 to 20%. 40% compounding amount
If it exceeds, the hiding power will decrease and the object on the back side will be visible.

The mirror coat layer 2 has a high refractive index.
Alternating material layers and low refractive index material layers one by one or alternating
The high refractive index material and low
Examples of the refractive index material include CaF_Two, NaF, Na
_ThreeAlF₆, LiF, MgF _Two, SiO_Two, LaF_Three,
NdF_Three, Al_TwoO_Three, CeF_Three, PbF_Two, MgO,
ThO_Two, SnO_Two, La_TwoO_Three, SiO, In
_TwoO_Three, Nd_TwoO_Three, Sb_TwoO_Three, ZrO_Two, Ce
O_Two, TiO_Two, ZnS, Bi_TwoO_Three, ZnSe, Cd
S, Sb_TwoS_Three, CdTe, Si, Ge, Te and P
bTe can be mentioned, and of these, the high refractive index
It is possible to select and use two types of substances,
Can be used.

The high refractive index material layer has a refractive index of 1.4 to
5.5, the low refractive index material layer has a refractive index of 1.2 to 4.9.
Is preferable, and the difference in refractive index between the two is 0.5 to
It is preferably 1.2. With such a configuration, it is easy for the object to be coated to exhibit a glittering feeling such as plating to give a high-class feeling, and the hiding property is easily improved.

In this case, the high refractive index substance and the low refractive index substance can be formed into a thin film of about 0.1 to 0.2 μm by a vacuum deposition method, an ion plating method and a sputtering method. ₂ thin film and SiO ₂
The mirror coating layer can be formed by alternately laminating a total of 10 thin films.

Furthermore, the color material layer 4 contains at least one kind of color material capable of absorbing visible light in a part of wavelength range and transmitting infrared light. 1
As the coloring material binder in which one or more coloring materials are mixed, a generally known film-forming polymer can be contained, and for example, acrylic resin, alkyd resin, polyester resin, polyurethane resin and amino resin can be used.

At this time, as a curing agent, for example, an alkoxymethylol melamine resin, an isocyanate compound or a blocked isocyanate compound, a polyacid anhydride and a polyepoxy compound can be contained. It is also possible to add a polymer such as nitrocellulose resin or polymer acrylic resin, which is a polymer that forms a film when a solvent evaporates, or an alkyd resin, which is a polymer that forms a film by reacting with oxygen or moisture in the air. it can. Further, a solvent capable of dissolving or dispersing the above-mentioned polymer or curing agent, for example, toluene, xylene, butyl acetate, methyl acetate, methyl ethyl ketone, methyl isobutyl ketone, butyl alcohol, aliphatic hydrocarbon and aromatic hydrocarbon may be added. Good. The solvent is not limited to the organic solvent, and an inorganic solvent such as water may be used.

As the above color material, 750 to 1000 nm
A dye or pigment that can transmit infrared rays in the wavelength range of can be used, for example, azo dye, anthraquinone dye, naphthol dye, polymethine dye, cadmium red,
Examples include cobalt blue, isoindolinone, phthalocyanine blue, induslen blue, perylene red, bismuth yellow and azo compounds. These coloring materials are not limited to being used alone, but may be used as a mixture of two or more kinds. The coloring material may be mixed in an amount of about 0.1 to 100 parts by weight with respect to 100 parts by weight of the binder, but the infrared sensor cover according to the present invention has an infrared transmittance of 70%.
Since it is required to be above, the infrared transmittance of the mirror coat layer is set to 90 to 100%, and the color material layer 4 has a predetermined film thickness (for example, about 30 μm) and the infrared transmittance of the color material is 70%. It is desirable to set the above.

Furthermore, in the infrared sensor cover according to the present invention, a protective layer 3 containing a protective material capable of transmitting visible rays and infrared rays can be laminated, whereby the surface of the infrared sensor cover is not scratched or damaged. The weather resistance can be improved.

The protective material contained in the protective layer 3 is
Examples thereof include acrylic silicone-based paints, silicone-modified alkyd-based paints, and silicone-modified urethane-based paints.

Furthermore, the protective layer 3 and / or the color material layer 4 may contain an ultraviolet absorber having an absorption spectrum in the ultraviolet wavelength range and capable of transmitting visible rays and infrared rays. It is effective because the weather resistance can be improved.

As such an ultraviolet absorber, one that does not absorb light in the visible to infrared wavelength range is selected.
Specifically, benzotriazole type, benzophenone type,
Examples thereof include benzoate type and cyanoacrylate type. At this time, a hindered amine-based light stabilizer can be added to these ultraviolet absorbers, whereby the weather resistance is further improved.

It is desirable that the amount of these ultraviolet absorbers and light stabilizers is about 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin.

Next, the infrared sensor cover of the present invention will be described in detail.

This infrared sensor cover is characterized by having an infrared transmittance of 70% or more. This allows
A cover having a desired shape can be installed even on the infrared optical path of the infrared sensor, and the concealing property of the infrared sensor and the design from the outside can be secured. The infrared transmittance is 70
If it is less than%, the infrared sensor cover will be an obstacle on the infrared optical path, and it will be difficult to operate the infrared sensor normally.

Next, the infrared sensor unit of the present invention will be described in detail.

This infrared sensor unit is characterized by including the above-mentioned infrared sensor cover. As a result, the infrared sensor has a higher concealing property than the conventional infrared sensor unit, and the function of the infrared sensor is not deteriorated. In addition, the shape and the like can be freely designed, so that the design is improved.

[0028]

EXAMPLES The present invention will be described in detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Example 1) Polycarbonate which transmits infrared rays (trade name: Lexan 143-71280, G
A part of the surface of a black base material molded by E Plastics Co., Ltd. was masked, and after performing a cold mirror treatment of a total of 15 layers composed of TiO ₂ —SiO ₂ , the masking was peeled off, and this example was used. Got the infrared sensor cover.

(Example 2) Polycarbonate which transmits infrared rays (trade name: Lexan 143-71280, G
A black substrate formed by E Plastics Co., Ltd. is subjected to cold mirror treatment of a total of 10 layers made of TiO ₂ —SiO ₂ on the entire surface, and a part of the mirror-coated surface is masked. A perylene red pigment (trade name: Perint Maroon R6436, manufactured by Bayer Co., Ltd.), a cyanine blue pigment (trade name: Cyanine Blue G314, manufactured by Sanyo Dye Co., Ltd.), and a bismuth yellow pigment (trade name: Irga Color urethane 2GLMA, Ciba Specialty Chemicals Co., Ltd.) mixed in the same amount of mixed pigments in an amount of 2.5 parts by weight based on 100 parts by weight of the resin acrylic urethane coating (trade name: R241,
The infrared sensor cover of this example was obtained by coating 30 μm of dry film thickness manufactured by Nippon Bee Chemical Co., Ltd. and then removing the masking.

Example 3 The infrared sensor cover of this example was obtained by repeating the same operation as in Example 2 except that a total of 15 layers of cold mirror treatment were performed.

(Comparative Example 1) An infrared sensor cover of this example was obtained by repeating the same operation as in Example 2 except that a total of 33 layers of cold mirror treatment were performed.

Comparative Example 2 TiO ₂ -Si was formed on the surface of a transparent base material formed of transparent polycarbonate (trade name: LM300, manufactured by Mitsubishi Engineering Plastics Co., Ltd.).
A perylene red pigment (trade name: Perint Maroon R6436, manufactured by Bayer Co., Ltd.) is obtained by performing a total of 15 layers of cold mirror treatment composed of O ₂ and masking a part of the mirror-coated surface. , Cyanine blue pigment (trade name: Cyanine Blue G314, Sanyo Dye Co., Ltd.) and bismuth yellow pigment (trade name: Irga Color Yellow 2GLMA, Ciba Specialty Chemicals Co., Ltd.) mixed in equal amounts Pigment Resin 1
Acrylic urethane coating compounded with 2.5 parts by weight to 00 parts by weight (trade name: R241, Nippon Bee Chemical Co., Ltd.)
(Manufactured) was applied to a dry film thickness of 30 μm, and then the masking was peeled off to obtain an infrared sensor cover of this example.

(Comparative Example 3) Acrylic urethane paint containing carbon black (trade name: R241, manufactured by Nippon Bee Chemical Co., Ltd.) was coated on the side opposite to the mirror-coated surface in a dry film thickness of 30 μm, except that The same operation as in Comparative Example 2 was repeated to obtain the infrared sensor cover of this example.

(Comparative Example 4) Polycarbonate which transmits infrared rays (trade name: Lexan 143-71280, G
A black base material formed by E Plastics Co., Ltd. is subjected to a cold mirror treatment of a total of 15 layers made of TiO ₂ —SiO ₂ on the entire surface, and a part of the mirror-coated surface is masked. Then, an acrylic urethane coating containing carbon black (trade name: R241, manufactured by Nippon Bee Chemical Co., Ltd.) was applied to a dry film thickness of 30 μm, and then the masking was peeled off to obtain an infrared sensor cover of this example.

[Performance Evaluation] Regarding the infrared sensor cover obtained in each example, the spectral reflectance of 360 to 900 nm
The transmittance was measured with a spectrophotometer (U-4000: manufactured by Hitachi, Ltd.), and the reflectance / transmittance at 400 nm, 500 nm, and 600 nm was defined as the reflectance / transmittance of visible light, and 85
The transmittance of 0 nm was defined as the infrared transmittance.

The reflectance was measured by making light incident on the mirror-coated portion from the mirror-coated surface side, and the transmittance by making light incident on the smallest number of layers from the coated surface side.

As for the appearance of the image of the mirror coat layer, the infrared sensor cover obtained in each example was held by hand in a sufficiently bright room and raised to the height of the shoulder without bending the arm. The face was photographed on a mirror coat, and the appearance of the image was evaluated.

Further, regarding the heat resistance, the infrared sensor cover obtained in each example was put in a constant temperature bath at 80 ° C. for 24 hours, and after taking out, it was visually evaluated whether or not the mirror coat treatment had cracks. did.

The evaluation results of each example are shown in Table 1.

[0041]

[Table 1]

As shown in Table 1, the infrared sensor covers obtained in Examples 1 and 2 are the preferred embodiments of the present invention. Even if the number of laminated layers is small, visible light reflectance / transmittance, image It can be seen that the image quality and heat resistance are excellent. On the other hand, it is understood that the infrared sensor covers obtained in Comparative Examples 1 to 4 are out of the preferred range of the present invention and the above effects are not obtained.

Although the present invention has been described in detail with reference to the embodiments, the present invention is not limited to these, and various modifications can be made within the scope of the gist of the present invention. When manufacturing each component of the infrared sensor cover, various additives such as a filler such as a lubricant, an antistatic agent and an antioxidant, and a reinforcing agent can be appropriately added.

[0044]

As described above, according to the present invention, a black synthetic resin layer capable of transmitting infrared rays and a high refractive index substance layer partially formed on one surface of the black synthetic resin layer are provided. A structure in which a mirror coat layer in which a refractive index material layer is alternately laminated one by one or a plurality of layers is alternately laminated, or these black synthetic resin layer and mirror coat layer absorb visible light in a part of wavelength range. In addition, since the color material layer containing at least one kind of color material capable of transmitting infrared rays is added, infrared rays in which the number of layers of the high refractive index substance layer and the low refractive index substance layer constituting the mirror coat layer is reduced It is possible to provide a sensor cover and an infrared sensor unit, that is, an infrared sensor cover capable of exerting a decorative function of a mirror coat in addition to the original protective function of the cover. It can provide over and infrared sensor unit.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an infrared sensor cover of the present invention.

FIG. 2 is a cross-sectional view showing another example of the infrared sensor cover of the present invention.

[Explanation of symbols]

1 Black Synthetic Resin Layer 2 Mirror Coat Layer (High Refractive Index Material Layer + Low Refractive Index Material Layer) 3 Coloring Material Layer (Coloring Material Containing Infrared Transmitting Material) 4 Protective Layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02B 5/22 G02B 5/22 5/26 5/26 (72) Inventor Tamami Otsuki Kanagawa Ward, Kanagawa Yokohama 2 Takaramachi Nissan Motor Co., Ltd. F term (reference) 2G065 AA04 AB02 BB26 BB50 2H042 DA08 DA11 DA17 DA21 DB03 DC02 DC04 DE00 DE01 DE09 2H048 CA01 CA04 CA14 CA17 CA24 CA27

Claims (6)

[Claims] 1. A black synthetic resin layer capable of transmitting infrared rays,
The black synthetic resin layer includes a mirror coat layer in which high refractive index material layers and low refractive index material layers partially formed on one surface of this black synthetic resin layer are alternately laminated one by one or alternately. Also, an infrared sensor cover having an infrared transmittance of 70% or more in a state where the mirror coat layer is laminated. 2. A black synthetic resin layer capable of transmitting infrared rays,
A mirror coat layer in which a high refractive index substance layer and a low refractive index substance layer, which are formed on the entire surface of one surface of the black synthetic resin layer, are alternately laminated one by one or alternately by a plurality of layers, and a mirror of this mirror coat layer. A black synthetic resin layer, a mirror coat layer, and a color layer, which include a coloring material layer containing at least one coloring material capable of absorbing visible light partially formed on the coated surface in a partial wavelength range and transmitting infrared rays. An infrared sensor cover having an infrared transmittance of 70% or more in a state where material layers are laminated. 3. The infrared sensor cover according to claim 1, wherein a protective layer containing a protective material capable of transmitting visible light and infrared light is laminated. 4. The infrared sensor cover according to claim 2, wherein the color material layer contains an ultraviolet absorber having an absorption spectrum in the ultraviolet wavelength range and transmitting visible rays and infrared rays. 5. The infrared sensor cover according to claim 3, wherein the protective layer contains an ultraviolet absorber having an absorption spectrum in the ultraviolet wavelength range and capable of transmitting visible rays and infrared rays. 6. An infrared sensor unit comprising the infrared sensor cover according to any one of claims 1 to 5.