JP2015108790A - Light reflective member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light reflective member which has good light reflectivity and also exhibits superior peeling resistance and moisture resistance.SOLUTION: A light reflective member 10 comprises a substrate 1, a reflective layer 3 containing silver and having a thickness of 20 nm or greater, a first protective layer 2 (first layer) formed between the substrate 1 and the reflective layer 3, and a second protective layer 4 (second layer) formed on the reflective layer 3 on a side opposite the first protective layer 2 (first layer), where at least either of the first protective layer 2 (first layer) and the second protective layer 4 (second layer) contains amorphous zinc sulfide.

Description

  The present invention relates to a light reflecting member.

  Silver having excellent light reflectivity is used as a material for a light reflecting member. Such a reflective member is installed in the vicinity of, for example, a solar cell, and is installed in the vicinity of an application for concentrating sunlight efficiently or in a headlight of an automobile, and reflects light emitted from the light. It is used for applications that are released to the outside. Moreover, the light reflection member comprised using the film-form base material is also used as what is called a film mirror.

As a technique relating to a light reflecting member using silver, for example, a technique described in Patent Document 1 is known. Patent Document 1 describes a light reflecting member including a silver layer, a shielding layer, and a zinc sulfide layer. Patent Document 2 and Non-Patent Document 1 describe forming a layer (ZnS—SiO ₂ ) containing silicon dioxide in zinc sulfide in a transparent conductive film including a silver layer.

Japanese Patent Laid-Open No. 06-313803 Chinese Patent Application No. 1026777012

Applied Surface Science, 263, p.546-552 (2012)

  When producing a light reflection member using silver, it is preferable that the thickness of the reflection layer is sufficiently thick from the viewpoint of sufficiently ensuring the light reflectivity of the reflection layer containing silver. However, as the thickness of the reflective layer is increased, in particular, the layer in contact with the reflective layer tends to be peeled off from the reflective layer. Especially, a light reflection member may be installed in the place where a vibration is easy to generate | occur | produce, and it will cause the performance fall of a light reflection member because peeling of a layer arises by vibration. Further, the film-like light reflecting member (film mirror) can be bent, but such peeling may occur even when the film mirror is repeatedly bent. That is, the conventional technique has a problem in peel resistance (adhesiveness), for example, there is a problem that the life of the film mirror tends to be shortened.

  In addition, for example, when a light reflecting member is used in a hot and humid place, the reflecting layer containing silver deteriorates due to moisture, sulfide, oxygen, halogen, etc. that can be contained in the atmosphere and the layer constituting the light reflecting member. easy. That is, the reflective layer containing silver has a problem in durability depending on the use environment and the layer configuration of the light reflecting member.

  Therefore, the problem to be solved by the present invention is to provide a light reflecting member that exhibits good light reflectivity and is excellent in peeling resistance and durability.

  As a result of intensive studies to solve the above problems, the present inventors have found the following findings. That is, the gist of the present invention is as follows.

1. A substrate;
A reflective layer containing silver and having a thickness of 20 nm or more;
A first layer formed between the substrate and the reflective layer;
A second layer formed on the opposite side of the reflective layer from the first layer,
At least one of said 1st layer and said 2nd layer contains amorphous zinc sulfide, The light reflection member characterized by the above-mentioned.

2. The layer containing amorphous zinc sulfide is
Zinc sulfide,
At least one metal material selected from the group consisting of metal oxides, metal fluorides and metal nitrides;
2. The light reflecting member according to 1 above, comprising:

  3. 3. The light reflecting member according to 1 or 2, wherein a thickness of the amorphous zinc sulfide-containing layer in at least one of the first layer and the second layer is 40 nm or more. .

  ADVANTAGE OF THE INVENTION According to this invention, while showing favorable light reflectivity, the light reflection member excellent also in peeling resistance and durability can be provided.

It is sectional drawing which shows the light reflection member of this embodiment.

  Hereinafter, a form (this embodiment) for carrying out the present invention will be described. However, the present embodiment is not limited to the following contents, and can be arbitrarily modified and implemented without departing from the gist of the present invention.

[1. Light reflecting member]
As shown in FIG. 1, the light reflecting member 10 of the present embodiment is formed between the base material 1, the reflective layer 3 containing silver and having a thickness of 20 nm or more, and the base material 1 and the reflective layer 3. A first protective layer 2 (first layer), a second protective layer 4 (second layer) formed on the opposite side of the reflective layer 3 from the first protective layer 2 (first layer), Is provided. In the present embodiment, both the first protective layer 2 (first layer) and the second protective layer 4 (second layer) contain amorphous zinc sulfide. However, although details will be described later, it is not necessary that both the first protective layer 2 (first layer) and the second protective layer 4 (second layer) contain amorphous zinc sulfide, at least one of them. It suffices if amorphous zinc sulfide is included.

(Substrate 1)
The substrate 1 supports the first protective layer 2, the reflective layer 3, the second protective layer 4, and the like. The base material 1 may have any shape as long as it can support each of these layers, and may be composed of any material. Examples of the shape of the substrate 1 include a plate shape, a film shape, and a lens shape, and an arbitrary structure. Moreover, as a material which comprises the base material 1, glass, resin, etc. are mentioned, for example. Among these, it is preferable that the base material 1 is a resin film from a viewpoint of handleability or versatility.

  Examples of the resin film include cellulose ester film, polyester film, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene terephthalate, polyester film such as polyethylene naphthalate, polyethylene film, Polypropylene film, cellophane, cellulose diacetate film, cellulose triacetate film, cellulose acetate propionate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film Norbornene resin film Polymethyl pentene film, polyether ketone film, polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, polymethyl methacrylate film, and the like acrylic film. One of these may be used alone, or two or more thereof may be used in any ratio and combination.

  Among these, as the substrate 1, a polycarbonate film, a polyester film, a norbornene resin film, a cellulose ester film, and an acrylic film are preferable, and a polyester film and an acrylic film are more preferable. The resin film may be a film manufactured by melt casting film formation or a film manufactured by solution casting film formation.

  The thickness of the substrate 1 is not particularly limited. Therefore, the thickness of the base material 1 may be appropriately set according to the use of the light reflecting member 10 or the like. The thickness of the substrate 1 is, for example, usually 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more, and usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less.

(First protective layer 2)
The first protective layer 2 is formed on the surface of the substrate 1 and contains amorphous zinc sulfide. Thereby, the water | moisture content etc. which permeate | transmitted the base material 1 or contained in the base material 1 itself can be prevented more reliably, and higher durability can be acquired. Moreover, the peeling resistance of the light reflection member 10 can be improved more by making the 1st protective layer 2 bear the role which connects the base material 1 and the reflection layer 3. FIG.

  However, although it is preferable that both the first protective layer 2 and the second protective layer 4 (described later) include amorphous zinc oxide, at least one of the first protective layer 2 and the second protective layer 4 is amorphous. It suffices if zinc sulfide is included, and the first protective layer 2 is not necessarily required to contain amorphous zinc sulfide. Therefore, if the second protective layer 4 to be described later contains amorphous zinc sulfide, the first protective layer 2 does not necessarily need to contain amorphous zinc sulfide.

  The zinc sulfide contained in the first protective layer 2 may be made amorphous by any method. For example, an amorphous zinc sulfide can be obtained by adding (doping) a material made of any oxide, fluoride, or nitride to crystalline zinc sulfide to destroy the crystallinity of zinc sulfide. it can. Such oxide, fluoride, and nitride materials are not particularly limited, but include oxides (metal oxides) and fluorides (metal fluorides, including metalloids (including silicon), the same applies hereinafter). ) And nitrides (metal nitrides) are preferred. Hereinafter, “metal oxide, metal fluoride, and metal nitride” are collectively referred to as “amorphized metal material” as appropriate.

  Here, the reason why zinc sulfide can be made amorphous by using an amorphized metal material will be described. When a material containing a crystalline zinc sulfide and an amorphizing material is formed, the same kind of materials (zinc sulfides, amorphizing materials) tend to gather in the formed film. In order for zinc sulfide to crystallize (crystal growth) in the formed film, it is preferable that the bonds between zinc sulfides exist continuously for a long period. However, in this embodiment, since the amorphous material is also included in the film, the zinc sulfide bond is cut at the interface with the region where the amorphous material exists. As a result, a long-period continuous bond of zinc sulfide is broken, and an amorphous, that is, amorphous zinc sulfide film is formed.

  In particular, in the present embodiment, metal oxide, metal fluoride, and metal nitride are used as the amorphizing material. These contained elements such as oxygen, fluorine, and nitrogen are easier to chemically bond with zinc contained in zinc sulfide than hydrogen and chlorine. Furthermore, since the electronegativity of oxygen, nitrogen, and fluorine is larger than the electronegativity of boron, phosphorus, etc., it is easier to chemically bond to zinc contained in zinc sulfide. Therefore, the use of metal oxides, metal fluorides, and metal nitrides as the amorphizing material particularly facilitates bridging between zinc contained in zinc sulfide and oxygen, fluorine, and nitrogen contained in the amorphizing material. It is. As a result, by using the amorphized material, the amorphized material penetrates into the crystal of zinc sulfide, the crystal structure of zinc sulfide is more easily cut, and the amorphization of zinc sulfide is particularly promoted. Become.

Zinc sulfide made amorphous using an amorphized metal material has better light transmittance. Therefore, it is possible to sufficiently suppress a decrease in reflectance due to the provision of the first protective layer 2. The content of the amorphized metal material in the first protective layer 2 can be appropriately changed, whereby the refractive index of light can be changed. Therefore, the light transmittance can be set as desired. Specifically, for example, the first protective layer 2 contains, for example, TiO ₂ or Nb ₂ O ₅ which is a transparent material having a higher refractive index than zinc sulfide, so that it is not amorphized (ie, crystalline) zinc sulfide. Compared with a protective layer made of a single substance, the reflection band can be expanded. Thereby, adjustment of the optical characteristic of the light reflection member 10 becomes easy.

Further, zinc sulfide made amorphous by using these has better durability. Therefore, it is possible to more reliably protect the reflective layer 3 described later. Further, by including Si ₃ N ₄ , Al ₂ O _3, etc., it becomes possible to improve the scratching property of the light reflecting member 10 of the present embodiment.

Specific examples of the metal oxide include TiO ₂ , In ₂ O ₅ , ZnO, Nb ₂ O ₅ , ZrO ₂ , CeO ₂ , Ta ₂ O ₅ , Ti ₃ O ₅ , Ti ₄ O ₇ , Ti ₂ O ₃ , TiO, SnO ₂ , La ₂ Ti ₂ O ₇ , ITO (InSnO), IGZO (InGaZnO), IZO (InZnO), AZO (AlZnO), GZO (GaZnO), ATO (AlSnO), ICO (InCeO), Bi ₂ O _{3, a-GIO (GaInO)} , Ga 2 O 3, GeO 2, SiO 2, Al 2 O 3, HfO 2, SiO, MgO, Y 2 O 3, WO 3 , and the like.

Among these, SiO ₂ and TiO ₂ are preferable. When SiO ₂ is used, zinc sulfide can be made amorphous even if its content is small. Therefore, by incorporating the SiO _2, it is possible to after amorphization of zinc sulfide, particularly well exhibited a high adhesion (peeling resistance) and high durability (such as against moisture, etc.). In addition, since TiO ₂ exhibits a particularly high refractive index among transparent materials, by using TiO ₂ , the reflection band can be widened to increase the reflectance, and the reflection characteristics can be improved.

Specific examples of the metal fluoride include LaF ₃ , BaF ₂ , Na ₅ Al ₃ F ₁₄ , Na ₃ AlF ₆ , AlF ₃ , MgF ₂ , CaF ₂ , BaF ₂ , CeF ₃ , NdF ₃ , YF _{3 and the} like. Is mentioned.

Further, specific examples of the metal nitride include Si ₃ N ₄ and AlN. Among these, Si ₃ N ₄ is preferable. Since Si ₃ N ₄ has high hardness, the scratch resistance of the first protective layer 2 can be improved by using Si ₃ N ₄ .

  In addition, these may be used individually by 1 type, and 2 or more types may be used by arbitrary ratios and combinations.

  In order to obtain amorphous zinc sulfide, there is no particular limitation on the amount of the amorphized metal material contained with respect to crystalline zinc sulfide. For example, although it cannot be generally described because it varies depending on the type of amorphized metal material, when silicon dioxide is used as the amorphized metal material, it is usually 1% by mass or more, preferably 5% by mass with respect to crystalline zinc sulfide. As described above, amorphous zinc sulfide can be obtained by containing 99% by mass or less, preferably 95% by mass or less of silicon dioxide.

  Although there is no restriction | limiting in particular in the quantity of the amorphous zinc sulfide contained in the 1st protective layer 2, It is preferable that the 1st protective layer 2 consists of an amorphous zinc sulfide. That is, it is preferable that all the materials constituting the first protective layer 2 are amorphous zinc sulfide. Thereby, durability, exfoliation resistance, etc. can be improved further.

  The thickness of the first protective layer 2 is not particularly limited, but is preferably as thick as possible. Specifically, it is preferably 20 nm or more, more preferably 40 nm or more, and even more preferably 85 nm or more. By making the thickness of the 1st protective layer 2 into this range, especially peeling resistance can be improved more.

(Reflection layer 3)
The reflective layer 3 is formed on the surface of the first protective layer 2 opposite to the base 1 and reflects light incident from the outside and emits it to the outside. The reflective layer 3 contains silver. By including silver in the reflective layer 3, particularly high reflectance can be obtained for light having a wavelength of 370 nm or more (visible light, infrared light, or the like).

  The reflective layer 3 may contain a material other than silver as long as the effects of the present invention are not significantly impaired. Moreover, the content can also be arbitrarily set in the range which does not impair the effect of this invention remarkably. Examples of the material that may be included include metals such as bismuth, palladium, copper, gold, nickel, aluminum, iron, cobalt, tungsten, molybdenum, tantalum, chromium, indium, manganese, titanium, palladium, and neodymium. Can be mentioned. One of these may be included alone, or two or more thereof may be included in any ratio and combination.

  Among these, it is preferable that the reflective layer 3 contains at least one kind of bismuth, palladium, and copper in addition to silver. At this time, the reflective layer 3 may be in the form of a simple substance or compound of silver and a simple substance or compound of bismuth, palladium, or copper, or in the form of an alloy of silver and at least one of these metals. It may be. Especially, it is preferable that the reflective layer 3 contains an alloy of silver and at least one of these metals, and the reflective layer 3 is made of an alloy of silver and at least one of these metals. Is preferred. That is, it is preferable that all of the materials constituting the reflective layer 3 are an alloy of silver and at least one of these metals. By including at least one of these metals in the reflective layer 3, it is possible to further improve the durability and peel resistance of the light reflecting member 10.

  The thickness of the reflective layer 3 is 20 nm or more, but is preferably as thick as possible from the viewpoint of obtaining a better reflectance. Specifically, it is preferably 80 nm or more. However, it is preferably 400 nm or less, more preferably 300 nm or less, and still more preferably 250 nm or less from the viewpoint of obtaining good flexible performance when a film-like light reflecting member is obtained.

(Second protective layer 4)
The second protective layer 4 is formed on the surface of the reflective layer 3 opposite to the first protective layer 2. Since the second protective layer 4 has the same configuration (composition, thickness, etc.) as the first protective layer 2 in this embodiment, the description thereof is omitted. However, as described above, at least one of the first protective layer 2 and the second protective layer 4 only needs to contain amorphous zinc sulfide. Therefore, if the first protective layer 2 contains amorphous zinc sulfide, the second protective layer 4 does not necessarily need to contain amorphous zinc sulfide.

  As described above, the thickness of the first protective layer 2 is preferably 40 nm or more, and the thickness of the second protective layer 4 is also preferably 40 nm or more. However, it is not always necessary that the thickness of both the first protective layer 2 and the second protective layer 4 is 40 nm or more, and sufficiently good performance is obtained when the thickness of at least one of these is 40 nm or more. Is obtained.

(Other layers)
In the light reflecting member 10 of the present embodiment, as shown in FIG. 1, three layers (first protective layer 2, reflective layer 3, and second protective layer 4) are formed on the surface of the base material 1. However, any layer other than these layers may be formed on the light reflecting member 10 as long as the effects of the present invention are not significantly impaired.

  That is, at least one layer (the first layer and the second layer. In the present embodiment, the first protective layer 2 and the second protective layer 4) may be formed on both sides of the reflective layer 3, respectively. Is optional. Further, as described above, it is sufficient that at least one of the first layer and the second layer includes amorphous zinc sulfide, and does not include amorphous zinc sulfide of these layers. The layer structure is also arbitrary. Therefore, the following layers are mentioned as another layer formed in the light reflection member 10, and the layer which does not contain amorphous zinc sulfide among the 1st layer and the 2nd layer, for example.

  For example, an intermediate layer can be formed between the first protective layer 2 and the reflective layer 3 or between the reflective layer 3 and the second protective layer 4. The intermediate layer is formed to avoid direct contact between the first protective layer 2 or the second protective layer 4 and the reflective layer 3. Thereby, the light reflectivity fall by sulfur reacting with the silver contained in the 1st protective layer 2 or the 2nd protective layer 4, and the silver contained in the reflection layer 3 by becoming black silver sulfide more reliably is prevented. it can.

The material constituting the intermediate layer is not particularly limited. For example, as such a material, a material that has high adhesion to the first protective layer 2 and the second protective layer 4 and does not chemically react with the reflective layer 3 is preferable. Specifically, for example, ZnO, ITO, IGZO, Ga ₂ O ₃ , Nb ₂ O ₅ , SnO ₂ , Y ₂ O ₃ , M3 (registered trademark, manufactured by Merck Japan, a mixture of aluminum oxide and lanthanum oxide), _{TiO 2, In 2 O 5,} Nb 2 O 5, ZrO 2, CeO 2, Ta 2 O 5, Ti 3 O 5, Ti 4 O 7, Ti 2 O 3, TiO, La 2 Ti 2 O 7, IZO, Metal oxides such as AZO, GZO, ATO, ICO, Bi ₂ O ₃ , a-GIO, GeO ₂ , SiO ₂ , Al ₂ O ₃ , HfO ₂ , SiO, MgO, WO ₃ , LaF ₃ , BaF ₂ , _{Na 5 Al 3 F 14, Na} 3 AlF 6, AlF 3, MgF 2, CaF 2, BaF 2, CeF 3, NdF 3, YF 3 , etc. of metal _fluorides, Si ₃ N 4, AlN, etc. Metal nitrides and the like. One of these may be used alone, or two or more thereof may be used in any ratio and combination.

Among these, a metal oxide is preferable as a material constituting the intermediate layer, and among them, ZnO, ITO, IGZO, Ga ₂ O ₃ , Nb ₂ O ₅ , SnO ₂ , Y ₂ O ₃ and M3 are preferable. By forming the intermediate layer constituted by these, the adhesion with zinc sulfide contained in the first protective layer 2 and the second protective layer 4 can be further improved, and the durability can be further improved.

  Although the thickness of the intermediate layer is not particularly limited, it is unclear because it varies depending on the layer structure of other layers. For example, it is usually 0.1 nm or more, preferably 1 nm or more, and usually 10 nm or less, preferably 5 nm or less. It can be. By setting it as this thickness, it can prevent more reliably that the 1st protective layer 2, the 2nd protective layer 4, and the reflective layer 3 contact directly.

  In addition to the intermediate layer, the following layers can be formed. For example, from the viewpoint of improving the gas barrier property of the light reflecting member 10, a gas barrier layer containing, for example, an inorganic oxide (such as titanium oxide or indium tin oxide) may be formed. Further, for example, from the viewpoint of imparting antifouling properties and hard coat properties to the light reflecting member 10, an antifouling hard coat layer containing, for example, an acrylic resin may be formed. Further, for example, in order to further improve the reflectivity, an increased reflection layer in which a silicon dioxide layer and a titanium oxide layer are combined may be formed. The titanium oxide contained in the increased reflection layer may be replaced with, for example, titanium oxide containing zinc sulfide, or may be replaced with silicon nitride containing zinc sulfide. For example, from the viewpoint of improving the weather resistance of the light reflecting member 10, an ultraviolet absorbing layer containing an ultraviolet absorber may be formed.

[2. Manufacturing method of light reflecting member]
The light reflecting member 10 can be manufactured by any method. For example, each layer formed on the surface of the substrate 1 can be formed by either a wet method or a dry method, for example. The wet method is a general term for a plating method and a coating method, and is a method for forming a film by depositing a metal from a solution or a method for forming a film by applying a solvent containing metal, drying and sintering. . Specifically, for example, when the reflective layer 3 made of silver is formed, silver mirror reaction or silver fine particle coating can be used. On the other hand, the dry method is a general term for a vacuum film forming method. Specific examples include a resistance heating vacuum deposition method, an electron beam heating vacuum deposition method, and an ion beam assisted vacuum deposition method, a sputtering method, an ion plating method, and the like. These may be performed by appropriately combining two or more kinds. Further, the forming apparatus and the forming conditions to be used may be appropriately determined according to a desired forming method.

  Among these, dry methods such as sputtering and vapor deposition are preferable, and sputtering is particularly preferable. Since the kinetic energy of particles is higher in the sputtering method than in the vapor deposition method, the layers are more closely adhered to each other, and the durability, peel resistance, and the like can be further improved. Therefore, for example, when the light reflecting member 10 shown in FIG. 1 is manufactured by using the sputtering method, after forming the first protective layer 2 on the surface of the base material 1 by sputtering, the reflective layer 3 and the second protective layer 4 are then formed. By sequentially forming in this order by sputtering, the light reflecting member 10 shown in FIG. 1 can be manufactured.

[3. Use of light reflecting member]
The light reflecting member 10 of the present embodiment can be applied to any application. In particular, the light reflecting member 10 of the present embodiment exhibits good light reflectivity and durability. Therefore, the light reflecting member 10 of the present embodiment is suitable for applications in which these performances are utilized. Specifically, for example, the light reflecting member 10 of the present embodiment is suitable for applications that collect sunlight, such as a solar light collecting mirror and a solar power generation reflecting device.

  Furthermore, the light reflecting member 10 of this embodiment is also excellent in peel resistance. Therefore, for example, when it is attached to a device in which the direction of the solar cell changes depending on time, it can be installed without being peeled even in a place where vibration is generated and easily peeled off. In addition, the light reflecting member 10 of the present embodiment can be used well as a component (for example, an in-vehicle optical component) that constitutes a device exposed to vibration.

  Hereinafter, the present embodiment will be described more specifically with reference to examples.

  The light reflecting members of Examples 1 to 10 and Comparative Examples 1 and 2 were produced. And each performance evaluation was performed about each light reflection member.

[1. Production of light reflecting member]
<Example 1>
As the base material 1 shown in FIG. 1, a PET film having a thickness of 15 μm was used. And the 1st protective layer 2 which consists of amorphous zinc sulfide was formed on the base material 1 by the sputtering method using the magnetron sputtering device of L-430S-FHS made by ANELVA. Specifically, using an alloy containing 20% by mass of silicon dioxide as a target, DC sputtering was performed at a vacuum of 2.5 × 10 ⁻¹ Pa in an argon atmosphere and a target side power of 200 W at room temperature. Film formation was performed at a film formation rate of 0.5 nm / second. Thereby, the first protective layer 2 was formed. The thickness of the first protective layer 2 was 20 nm.

  A reflective layer 3 made of silver was formed on the surface of the formed first protective layer 2 in the same manner as the formation of the first protective layer 2. The thickness of the reflective layer 3 was 20 nm. Further, a second protective layer 4 having the same composition as that of the first protective layer 2 was formed on the surface of the reflective layer 3 in the same manner as the formation of the first protective layer 2. The thickness of the second protective layer 4 was 20 nm. In this manner, the light reflecting member of Example 1 was produced.

<Example 2>
A light reflecting member of Example 2 was produced in the same manner as Example 1 except that the thickness of the second protective layer 4 of Example 1 was 40 nm.

<Example 3>
A light reflecting member of Example 3 was produced in the same manner as in Example 1 except that the thickness of the first protective layer 4 of Example 1 was 40 nm.

<Example 4>
A light reflecting member of Example 4 was produced in the same manner as in Example 1 except that the thickness of the reflective layer 3 of Example 1 was set to 80 nm.

<Example 5>
A light reflecting member of Example 5 was produced in the same manner as in Example 1 except that the thickness of the first protective layer 2 of Example 4 was 40 nm and the thickness of the second protective layer 4 was 85 nm.

<Example 6>
In the same manner as in Example 4, the first protective layer 2 and the reflective layer 3 made of amorphous zinc sulfide were formed on the surface of the substrate 1. However, the thickness of the first protective layer 2 was 40 nm, and the thickness of the reflective layer 3 was 80 nm. Next, a layer made of titanium oxide was formed on the surface of the reflective layer 3 in the same manner as the formation of the first protective layer 2. The thickness of this layer was 100 nm. Then, an antifouling hard coat layer having a thickness of 10 μm was formed on the surface of the layer made of titanium oxide.

  The light reflecting member of Example 6 was produced as described above. That is, in the light reflecting member of Example 6, the second protective layer 4 in the light reflecting member of Example 1 is not formed, but a layer made of titanium oxide is formed instead.

<Example 7>
First, in the same manner as in Example 6, a layer made of titanium oxide was formed on the surface of the substrate 1. The thickness of this layer was 100 nm. Next, a reflective layer 3 (thickness 80 nm) was formed in the same manner as in Example 6. Finally, in the same manner as in Example 6, a second protective layer 4 made of amorphous zinc sulfide was formed. The thickness of the second protective layer 4 was 40 nm.

<Example 8>
In the light reflecting member of Example 5, the first intermediate layer (intermediate layer) is provided between the first protective layer 2 and the reflective layer 3, and the second intermediate layer is provided between the reflective layer 3 and the second protective layer 4. A light reflecting member of Example 7 was produced in the same manner as Example 5 except that the layer (intermediate layer) was formed.

  That is, the first protective layer 2 was formed on the surface of the substrate 1 in the same manner as in Example 5. Next, a first intermediate layer made of zinc oxide was formed on the surface of the formed first protective layer 2 in the same manner as the formation of the first protective layer 2. The thickness of the first intermediate layer was 3 nm. Then, the reflective layer 3 was formed on the surface of the formed first intermediate layer in the same manner as in Example 5, and then the second intermediate layer made of zinc oxide was formed in the same manner as in the first intermediate layer. The thickness of the second intermediate layer was 3 nm. Finally, the second protective layer 4 was formed in the same manner as in Example 5.

<Example 9>
A light reflecting member of Example 8 was produced in the same manner as in Example 5 except that a silver-bismuth alloy (1% by mass as a bismuth constituent ratio) was used in place of the silver of Example 5.

<Example 10>
A light reflecting member of Example 9 was produced in the same manner as in Example 8 except that a silver-bismuth alloy (similar to the composition used in Example 9) was used instead of silver in Example 8.

<Example 11>
In the light reflecting member of Example 10, the surface of the formed second protective layer 4 is made of a layer made of silicon dioxide having a thickness of 2 nm, a layer made of titanium oxide having a thickness of 16 nm, and silicon dioxide having a thickness of 80 nm. A light reflecting member of Example 11 is manufactured in the same manner as Example 10 except that a layer made of titanium oxide and a layer made of titanium oxide having a thickness of 78 nm (these are increased reflection layers) are further formed in this order. did. The layer made of silicon dioxide and the layer made of titanium oxide were both formed in the same manner as the first protective layer.

<Example 12>
A light reflecting member having the same layer structure as that of the light reflecting member of Example 4 was produced by a vapor deposition method using a vapor deposition apparatus Gener manufactured by Optran Co., instead of the sputtering method. Specifically, film formation was performed using resistance heating under the conditions of a vacuum degree of 1 × 10 ⁻³ Pa, 210 A without introduction gas, and a rate of 2.5 nm / second. Thus, a light reflecting member of Example 12 was produced. The film thickness was measured using a crystal resonator.

<Example 13>
A light reflecting member having the same layer configuration as that of the light reflecting member of Example 5 was produced by a vapor deposition method instead of the sputtering method. Specifically, each layer was formed using the apparatus of Example 12 to prepare a light reflecting member of Example 13.

<Example 14>
A light reflecting member having a layer structure similar to that of the light reflecting member of Example 8 was produced by vapor deposition instead of sputtering. Specifically, each layer was formed using the apparatus of Example 12, and a light reflecting member of Example 14 was produced.

<Example 15>
A light reflecting member of Example 15 was produced in the same manner as in Example 9 except that APC (silver-palladium-copper alloy) manufactured by Furuya Metal Co., Ltd. was used instead of the silver-bismuth alloy of Example 9.

<Example 16>
A light reflecting member of Example 16 was produced in the same manner as Example 10 except that APC (silver-palladium-copper alloy) manufactured by Furuya Metal Co., Ltd. was used instead of the silver-bismuth alloy of Example 10.

<Example 17>
A light reflecting member of Example 17 was produced in the same manner as in Example 11 except that APC (silver-palladium-copper alloy) manufactured by Furuya Metal Co., Ltd. was used instead of the silver-bismuth alloy of Example 10.

<Example 18>
A light reflecting member of Example 18 was produced in the same manner as in Example 5 except that titanium oxide was used in place of the silicon dioxide of Example 5.

<Example 19>
A light reflecting member of Example 19 was produced in the same manner as in Example 8 except that titanium oxide was used instead of silicon dioxide in Example 8.

<Example 20>
In place of the silicon dioxide used at the time of forming the first protective layer 2 and the second protective layer 4 in Example 11, titanium oxide is used, silver is used in place of the silver-bismuth alloy constituting the reflective layer 3, A light reflecting member of Example 20 was produced in the same manner as Example 11 except that zinc sulfide to which titanium oxide was added was used instead of the titanium oxide layer formed outside the second protective layer 4. .

<Example 21>
A light reflecting member of Example 21 was produced in the same manner as in Example 5 except that silicon nitride was used in place of the silicon dioxide of Example 5.

<Example 22>
A light reflecting member of Example 22 was produced in the same manner as in Example 8 except that silicon nitride was used instead of silicon dioxide in Example 8.

<Example 23>
A light reflecting member of Example 23 was produced in the same manner as in Example 20 except that silicon nitride was used instead of titanium oxide in Example 20.

<Example 24>
A light reflecting member of Example 24 was produced in the same manner as in Example 8 except that ITO was used in place of the zinc oxide of Example 8.

<Example 25>
A light reflecting member of Example 25 was produced in the same manner as Example 8 except that IGZO was used in place of the zinc oxide of Example 8.

<Example 26>
A light reflecting member of Example 26 was produced in the same manner as in Example 8 except that Ga ₂ O ₃ was used instead of zinc oxide in Example 8.

<Example 27>
A light reflecting member of Example 27 was produced in the same manner as in Example 8 except that Nb ₂ O ₅ was used in place of the zinc oxide of Example 8.

<Example 28>
A light reflecting member of Example 28 was produced in the same manner as Example 8 except that SnO ₂ was used in place of the zinc oxide of Example 8.

<Example 29>
A light reflecting member of Example 29 was produced in the same manner as in Example 8 except that Y ₂ O ₃ was used instead of zinc oxide in Example 8 and each layer was formed by the same vapor deposition method as in Example 12. .

<Example 30>
Example 8 except that M3 (registered trademark, manufactured by Merck Japan Co., Ltd., a mixture of aluminum oxide and lanthanum oxide) was used instead of the zinc oxide of Example 8, and each layer was formed by the same vapor deposition method as in Example 12. In the same manner, a light reflecting member of Example 30 was produced.

<Comparative Example 1>
A layer made of yttrium oxide was formed on the surface of the substrate 1 used in Example 1 by the apparatus used in Example 1. The thickness of this layer was 140 nm. Next, a layer made of crystalline zinc sulfide (thickness 55 nm), a reflective layer 3 made of silver (thickness 120 nm), a layer made of magnesium fluoride (thickness 55 nm), a layer made of yttrium oxide (thickness 20 nm) And a layer (thickness 40 nm) made of crystalline zinc sulfide was formed in the same manner in this order. Thereby, the light reflecting member of Comparative Example 1 was produced.

<Comparative Example 2>
A light reflecting member of Comparative Example 2 was produced in the same manner as in Example 5 except that the first protective layer 2 and the second protective layer 4 were formed of crystalline zinc sulfide.

<Comparative Example 3>
A light reflecting member having a layer structure similar to that of the light reflecting member of Comparative Example 2 was produced by a vapor deposition method instead of the sputtering method. Specifically, each layer was formed by the apparatus used in Example 12 to prepare a light reflecting member of Comparative Example 3.

[2. Performance evaluation method]
<Light reflectivity evaluation>
In order to examine how much light the light reflecting member reflects, the light reflectivity of the light reflecting member was evaluated. Evaluation of light reflectivity was performed as follows. That is, about the produced light reflection member, the reflectance of the light reflection member in the case of 5 degree incident angle was measured using VW method using Hitachi High-Technologies U4100. For the measured reflectance, a reflectance of 98% or more is “「 ”, a reflectance of 95% or more and less than 98% is“ ％ ”, a reflectance of 90% or more and less than 95% is“ ◯ ”, 10 The reflectance was evaluated as “Δ” for reflectances of 90% or more and less than 90%, and “×” for reflectances of less than 10%.

<Moisture resistance evaluation>
In order to evaluate the durability of the light reflecting member, moisture resistance (how much humidity the light reflecting member can withstand), which is a kind of durability, was evaluated. Evaluation of moisture resistance was performed as follows. That is, the produced light reflecting member was allowed to stand at 65 ° C. and 95% (relative humidity) for 100 hours, and then evaluated by visually observing the light reflecting member. Evaluation is “◎” when no crack or discoloration is observed, “◯” when almost no crack or discoloration is observed, “△” when crack or discoloration is slightly observed, crack or discoloration, etc. “×” indicates that a large number of are recognized.

<Peeling resistance evaluation>
In order to examine how hard the light reflecting member peels due to deterioration with time, peeling resistance was evaluated. The peel resistance was evaluated as follows. That is, the produced light reflecting member was allowed to stand at 65 ° C. and 95% (relative humidity) for 12 hours. Thereafter, the peel resistance was evaluated based on the degree of peeling when the adhesive tape was bonded to the end of the light reflecting member and pulled up in the vertical direction. The evaluation was “◎” for those that did not peel at all, “◯” for those that did not peel almost at all, “△” for those that had noticeable peeling around or part of the bonded part, The resulting product was designated as “x”.

[3. Evaluation results and examination]
The result of each evaluation about the light reflection member of Examples 1-30 and Comparative Examples 1-3 is shown in Table 1 with a layer structure. In addition, in the item of the layer configuration in Table 1, the number in parentheses represents the thickness (nm).

(1) About light reflectivity As shown in Examples 1 to 30, even if the reflective layer 3 is composed of a single silver, it is composed of a silver alloy (silver-bismuth alloy, silver-palladium-copper alloy). Even when the thickness of the reflective layer 3 was 20 nm or more, good light reflectivity was exhibited. Therefore, it can be set as the light reflection member which shows favorable light reflectivity because the reflection layer 3 contains silver and the thickness of the reflection layer 3 is 20 nm or more. Further, as shown in Example 8, Example 10, Example 11, Example 14, Example 16, Example 17, Example 19, Example 20, Example 22, and Example 23, an intermediate layer (oxidation) By forming a layer made of zinc, it was possible to prevent silver in the reflective layer 3 from being sulfided. Thereby, the high light reflectivity of silver was maintained and it was made more favorable light reflectivity.

  In addition, as shown in Example 5 and Example 13 and the like, each layer is formed by a vapor deposition method (Example 13 and the like), which is better than the case of forming by a sputtering method (Example 5 and the like). A good light reflectivity was obtained. This is thought to be due to the difference in the layer formation method. That is, the kinetic energy of the particles is smaller in the vapor deposition method than in the sputtering method. Therefore, when forming the 2nd protective layer 4 on the surface of the reflective layer 3 by vapor deposition, the spreading | diffusion of the particle | grains which comprise the 2nd protective layer 4 vapor-deposited can be suppressed, and generation | occurrence | production of silver sulfide etc. is suppressed especially. This is thought to be due to this.

  Furthermore, as shown in Example 11 and Example 17, the light reflectivity was improved by forming a layer made of silicon dioxide and an increased reflection layer made of titanium oxide. Therefore, by providing these layers, the light reflectivity could be further improved. Further, as shown in Example 20 and Example 23, the reflection-enhancing layer may be a layer made of silicon dioxide and a titanium oxide containing zinc sulfide (Example 20), or a layer made of silicon dioxide and zinc sulfide. Even the one made of silicon nitride containing (Example 23) showed good light reflectivity as well.

  From these results, it was found that all of the light reflecting members of the present embodiment showed good light reflectivity. In particular, an intermediate layer may be formed (Example 8, Example 10, Example 11, Example 14, Example 17, Example 19, Example 20, Example 22, Example 23), or an enhanced reflection layer ( It has been found that the light reflectivity is further improved by forming Example 11, Example 17, Example 20, and Example 23).

(2) Moisture resistance At least one of the first protective layer 2 and the second protective layer 4 (only the first protective layer 2 in Example 6, only the second protective layer 4 in Example 7, only Examples 6 and Except for Example 7, both) were formed, showing good moisture resistance. That is, by forming the first protective layer 2 and the second protective layer 4 using amorphous zinc sulfide, the moisture resistance was improved as compared with Comparative Examples 1 to 3 (Examples 1 to 30). ).

  The reason for this is considered to be that the first protective layer 2 and the second protective layer 4 are made amorphous, so that the lowering of the layer density due to pinhole and column growth is suppressed, and the density of the entire layer is increased. . And it is thought that this prevented that water permeate | transmitted a layer and improved moisture resistance. Furthermore, it is considered that the first protective layer 2 and the second protective layer 4 are made amorphous, so that the elastic modulus of the layer is increased and the layer can follow the bending of the light reflecting member. . That is, conventionally, when the light reflecting member is bent, a layer is cracked, and water enters from the crack (water permeability). However, as a result of the layer being able to follow the bending, the generation of cracks is suppressed, This is thought to be because the entry was suppressed.

  On the other hand, in Comparative Examples 1 to 3 in which neither the first protective layer 2 nor the second protective layer 4 is formed, cracks occurred in the light reflecting member. Therefore, it is considered that the moisture resistance is lowered because water easily enters the layer from the crack.

  Further, among Examples 1 to 30 in which at least one of the first protective layer 2 and the second protective layer 4 is formed, the first protective layer 2 and / or the second protective layer containing amorphous zinc sulfide. The thickness of the layer 4 was set to 40 nm or more, and each layer was formed by a sputtering method, whereby the moisture resistance was further improved (Example 2, Example 3, Example 5 to Example 11, Example 15 to Example 30). ). The reason for this is considered that the protective effect of the reflective layer 3 could be further increased by increasing the thickness of the first protective layer 2 and / or the second protective layer 4. Further, it is considered that the sputtering method has higher kinetic energy of the deposited particles than the vapor deposition method and diffuses widely on the base material 1, thereby increasing the film density and consequently suppressing water permeability. .

  And the thickness of the 1st protective layer 2 and the 2nd protective layer 4 which are formed is 20 nm or more as shown in Example 1 and Example 4 from a moisture resistant viewpoint. However, as the thickness of the first protective layer 2 and the second protective layer 4, it is more preferable that at least one of them (layer containing amorphous zinc sulfide) is 40 nm or more as described above.

  Furthermore, from the viewpoint of further improving the moisture resistance, it is preferable to form the reflective layer 3 from an alloy of silver and bismuth, as shown in Examples 9 to 11. This is considered to be because bismuth forms an oxidative passivation on the surface of the reflective layer 3, thereby blocking reactive particles such as water. Further, as shown in Examples 15 to 17, it is also preferable that the reflective layer 3 is formed of an alloy of silver, palladium, and copper. This is presumably because the moisture resistance of the layer was improved because palladium suppressed reaction deterioration due to gas and copper suppressed silver diffusion (migration).

  From these results, it was found that all of the light reflecting members of the present embodiment showed good moisture resistance. In particular, each layer is formed using a sputtering method while setting the thickness of the first protective layer 2 and the second protective layer 4 to 40 nm or more (Example 2, Example 3, Example 5 to Example 11, Example 15 to Example 30), and by adding bismuth, palladium, and copper to the reflective layer 3 (Examples 9 to 11, Examples 15 to 17), better durability may be obtained. all right.

  Further, in this example, evaluation was made by taking moisture resistance as an example of durability, but the light reflecting member of the present embodiment is not only for moisture but also sulfide or the like for the same reason as described above. It is considered that there is good resistance to oxygen, halogen, and the like. Therefore, according to the light reflecting member of this embodiment, it can be said that there is good durability against various components in addition to moisture resistance.

(3) About peeling resistance At least one of the first protective layer 2 and the second protective layer 4 (only the first protective layer 2 in Example 6, only the second protective layer 4 in Example 7, only Example 6 and By forming both in cases other than Example 7, the peel resistance of the light reflecting member was improved (Examples 1 to 30). That is, in Examples 1-30, peeling of each layer which comprises a light reflection member did not arise easily. On the other hand, conspicuous peeling occurred in Comparative Examples 1 to 3 in which the first protective layer 2 and the second protective layer 4 were not formed. In particular, in Comparative Example 3, noticeable peeling occurred as a whole.

  Moreover, in order to make it a layer structure which is hard to peel, it can be said that it is preferable to form by a sputtering method as shown in Example 1 to Example 11 and Example 15 to Example 28. This is because the sputtering method, which has higher kinetic energy of particles than the vapor deposition method, can improve the adhesion between the layers by diffusing the particles with the upper and lower layers and reducing the depletion at the interface. However, it is thought that it can be made difficult to peel off. However, even when formed by the vapor deposition method, the peel resistance could be improved by setting the thicknesses of the first protective layer 2 and the second protective layer 4 to 40 nm or more as shown in Example 13 and the like. . This is considered to be because the adhesion of the reflective layer 3 can be particularly improved by increasing the thickness, and the peel resistance is improved.

  Furthermore, it is preferable that the first protective layer 2 and the second protective layer 4 to be formed are as thick as possible. Specifically, from the viewpoint of peel resistance, as shown in Example 1 and Example 4, these thicknesses are preferably 20 nm or more. Moreover, as shown in Example 2, Example 3, etc., these thicknesses are more preferably 40 nm or more. By setting the thickness to 40 nm or more, for example, when Example 1 and Example 2 are compared, the evaluation of peel resistance can be improved from ○ to ◎. For example, when Example 12 and Example 13 are compared, evaluation of peeling resistance can be improved from (triangle | delta) to (circle).

  From these results, it was found that the light reflecting member of the present embodiment has a configuration in which the layers are not easily separated from each other. In particular, similarly to the moisture resistance, the thickness of the first protective layer 2 and the second protective layer 4 is set to 40 nm or more, or each layer is formed by using a sputtering method, thereby further enhancing this effect. It turns out that you can get.

(4) Summary From the above results, the light reflecting member of the present embodiment exhibits excellent light reflectivity and durability, and also has excellent peel resistance. Therefore, according to the light reflecting member of the present embodiment, even if the light reflecting member having various layer configurations is configured in a severe environment such as a place with high humidity or a lot of vibration, the durability is excellent. And peeling resistance is shown. And since the light reflection member of this embodiment is also excellent in light reflectivity, application to various uses as a light reflection member is anticipated.

  In this example, silicon dioxide (metal oxide) and silicon nitride (metal nitride) were used as materials for amorphizing crystalline zinc sulfide. As described above, metal fluoride was used. Similarly, it is considered that crystalline zinc sulfide can be made amorphous. However, as described above, the material used for the amorphization is not limited to these as long as the crystalline zinc sulfide can be amorphized.

  Furthermore, it is preferable that the thickness of the layer containing amorphous zinc sulfide is 40 nm or more among the first protective layer 2 and the second protective layer 4. Thereby, especially peeling resistance can be improved. Further, among the first protective layer 2 and the second protective layer 4, the thickness of the layer containing amorphous zinc sulfide is set to 40 nm or more, and each layer is formed by a sputtering method, so that moisture resistance can be particularly improved. it can. Therefore, although the light reflecting member of the present embodiment exhibits excellent light reflectivity, moisture resistance, and peel resistance, the layer structure of the light reflecting member is determined according to the desired performance among these. In particular, the desired performance can be obtained.

1 base material 2 first protective layer (first layer)
3 Reflective layer 4 Second protective layer (second layer)
10 Light reflecting member

Claims (3)

A substrate;
A reflective layer containing silver and having a thickness of 20 nm or more;
A first layer formed between the substrate and the reflective layer;
A second layer formed on the opposite side of the reflective layer from the first layer,
At least one of said 1st layer and said 2nd layer contains amorphous zinc sulfide, The light reflection member characterized by the above-mentioned. The layer containing amorphous zinc sulfide is
Zinc sulfide,
At least one metal material selected from the group consisting of metal oxides, metal fluorides and metal nitrides;
The light reflecting member according to claim 1, comprising: 3. The light reflection according to claim 1, wherein a thickness of the layer containing amorphous zinc sulfide in at least one of the first layer and the second layer is 40 nm or more. Element.

Images