WO2014155860A1 - Mirror unit and solar light reflection plate using same - Google Patents

Abstract

Provided is a mirror unit that is provided with: a frame body configured from a long first base material, and a long second base material that is provided to extend in parallel to each other from both the ends of the first base material, said ends being in the longitudinal direction of the first base material; a holding groove that is formed along the inner surface of the frame body, said holding groove being formed in the longitudinal direction of the frame body; and a resin mirror, which is attached by being fitted in the holding groove, and which has a metal reflecting layer and a protection layer in this order on a resin supporting body. A solar light reflection plate using the mirror unit is also provided.

Description

Mirror unit and solar reflector using the same

The present invention relates to a mirror unit and a sunlight reflecting plate using the mirror unit.

In recent years, research on alternative energy alternatives to fossil fuels typified by oil, coal, and natural gas has been actively conducted. In particular, natural energy such as solar light, wind power, and geothermal heat has attracted attention as clean energy without concern about resource depletion and global warming. Among these, solar energy using sunlight is expected to be further developed as energy that can be stably supplied.

On the other hand, however, solar energy has a problem of low energy density. In order to solve this problem, in recent years, attempts have been made to collect sunlight using a huge reflector.
Until now, a reflector for condensing sunlight has been used outdoors because it is installed outdoors and exposed to ultraviolet rays, heat, wind and rain, sand dust and the like caused by sunlight. However, although the glass-made reflecting mirror is excellent in weather resistance, there is a problem that there is room for improvement in handling property because it is heavy, easily broken, and lacks flexibility.

To solve the above problem, it is considered to replace the glass reflector with a light and flexible resin reflector. For example, a film mirror is disclosed in which a first stretched film and a second stretched film are laminated via an adhesive layer in a form sandwiching a silver reflective layer provided on the first stretched film ( For example, refer to JP2012-83527A). According to Japanese Patent Application Laid-Open No. 2012-83527, the main stretched directions of the first stretched film and the second stretched film are crossed at a specific angle of intersection so that they can be used for a long time in a harsh environment. However, it is said that a film mirror in which the mirror surface is not distorted and the decrease in regular reflectance is suppressed can be provided.

However, since the strength of the resin support in the film mirror is not sufficient, in practice, a thin sheet-like film mirror is generally used by being attached to a metal substrate such as an aluminum substrate (for example, (See ASEM 2009 3rd International Conference of Energy Sustainability (2009) P573-580.)

According to the study by the present inventors, although the metal reflective layer achieves an excellent reflectance, there is a concern about durability when used under severe conditions such as deserts.
Further, the process of bonding the thin sheet-like film mirror and the metal substrate to improve the strength is complicated, and there is a concern that the reflection performance may be deteriorated when fine wrinkles are generated in the bonding process. Further, the thermal expansion coefficient of the metal substrate and the resin support of the film mirror are greatly different. For this reason, due to the difference in physical properties between the film mirror and the metal substrate, when the film mirror is used for a long time under severe conditions, peeling occurs at the interface between the film mirror and the substrate, and the flatness of the metal reflective layer is impaired. Therefore, there is a concern that the regular reflectance and the light collection rate may be reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to easily manufacture a lightweight resin mirror without requiring a step of bonding a resin mirror including a resin support to a metal substrate. It is an object of the present invention to provide a mirror unit having excellent durability and durability even in a harsh environment, because the resin mirror is stably supported.
Another object of the present invention is to provide a solar reflector that is lightweight and has excellent weather resistance using the mirror unit of the present invention.

Specific means for solving the above problems are as follows.
<1> A frame body including a long first base material and a long second base material extending in parallel from both longitudinal ends of the first base material, and an inner surface of the frame body And a resin mirror having a metal reflective layer and a protective layer in this order on a resin support fitted and fitted in the holding groove. Mirror unit.
<2> The mirror unit according to <1>, wherein the resin mirror has a thickness of 0.2 mm to 5.0 mm.
<3> The mirror unit according to <1> or <2>, wherein the resin support of the resin mirror has a thickness of 90% to 99% with respect to the thickness of the resin mirror.
<4> The mirror unit according to any one of <1> to <3>, wherein the resin mirror is flexible.

<5> The mirror unit according to any one of <1> to <4>, further including a reinforcing member that is provided on the resin support side of the frame and is connected to the opposing second base material.
<6> The mirror unit according to <5>, wherein the reinforcing member is a plate that closes an opening of the frame.
<7><1> to <4> provided on the side of the resin support of the frame body, connected to an elongated first base material, and provided with a reinforcing member parallel to the opposing second base material. The mirror unit according to any one of the above.

<8> The mirror unit according to any one of <5> to <7>, further comprising a heat insulating layer between the reinforcing member and the resin mirror.
<9> The mirror unit according to any one of <1> to <8>, wherein a heat insulating layer is provided on a surface of the holding groove that contacts the resin mirror.

<10> The mirror unit according to any one of <1> to <9>, further including a resin mirror fixing member on a side of the frame body on which the resin mirror is inserted.
<11> The frame is curved so that the resin support side is convex, and the resin mirror is held so that the resin support side is convex. Any one of <1> to <10> The mirror unit described in the item.
<12> The mirror unit according to any one of <1> to <11>, which is used for collecting sunlight.

<13> A solar light reflector comprising the mirror unit according to any one of <1> to <12>, and a solar light tracking system that tracks the mirror unit in a diurnal motion of the sun.

In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
The description “(meth) acryl” means either or both of “acryl” and “methacryl”. Similarly, the description of (meth) acrylate means either or both of “acrylate” and “methacrylate”.

According to the present invention, a process of bonding a resin mirror to a metal substrate is not required, and it is easily manufactured and excellent in exchangeability and mountability of a lightweight resin mirror, and the resin mirror is stably supported. A mirror unit having excellent durability is provided even in a difficult environment.
In addition, by using the mirror unit of the present invention, a light reflecting plate that is lightweight and excellent in weather resistance is provided.

It is the schematic which shows an example of a structure of the frame of the mirror unit which concerns on one embodiment of this invention. It is the schematic which shows an example of a structure of the mirror unit which concerns on one embodiment of this invention. It is the schematic which shows an example of the 2nd aspect of the frame of the mirror unit which concerns on one embodiment of this invention. It is the schematic which shows an example of the 3rd aspect of the frame of the mirror unit which concerns on one embodiment of this invention. It is a schematic plan view which shows the modification of the reinforcement member in the frame of the mirror unit which concerns on one embodiment of this invention. It is a schematic plan view which shows the modification of the reinforcement member in the frame of the mirror unit which concerns on one embodiment of this invention. It is a schematic plan view which shows the modification of the reinforcement member in the frame of the mirror unit which concerns on one embodiment of this invention. It is a schematic plan view which shows the modification of the reinforcement member in the frame of the mirror unit which concerns on one embodiment of this invention.

Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the object of the present invention. be able to.

[Mirror unit]
The mirror unit of the present invention will be described with reference to FIGS. 1A and 1B. In the present specification, the same members are denoted by the same reference symbols throughout the drawings, and the repeated description is omitted as appropriate.
FIG. 1A is a schematic diagram illustrating an example of a frame 12 of a mirror unit according to an embodiment of the present invention, and FIG. 1B illustrates an example of a configuration of a mirror unit 10 in which a resin mirror 14 is inserted into the frame 12. FIG.
The frame 12 includes a long first base material 18 and long second base materials 16A and 16B extending in parallel from both ends in the longitudinal direction of the first base material 18. A holding groove 20 is provided in the longitudinal direction along the inner surface of the body 12.

On the frame body 12, a resin mirror 14 having a metal reflective layer and a protective layer in this order on a resin support is fitted into the holding groove 20 and mounted, so that the mirror unit 10 of the present embodiment. Is configured. The size of the frame 12 is appropriately adjusted as necessary. For example, the length of the first base material 18 is about 200 mm to 2000 mm, and the length of the second base materials 16A and 16B is about 300 mm to 6000 mm. Can do.

The material constituting the frame 12 is not particularly limited as long as it has the strength and durability required for the mirror unit, and examples thereof include resin, metal, ceramic, etc., preferably metal. . Examples of the metal include steel, copper, and aluminum. From the viewpoint of corrosion resistance, it is also preferable to apply plating to the frame made of metal.
Of these, aluminum and stainless steel represented by SUS are preferable from the viewpoint of durability and ease of processing. When the second base materials 16A and 16B of the frame body 12 form a curved surface, stainless steel is more preferable in terms of workability.

FIG. 2 is a schematic view showing an example (frame body 22) of the second embodiment of the frame body used in the mirror unit of the present invention. In this embodiment, the resin inserted in the frame body 22 is shown in FIG. On the resin support side of the mirror, a first reinforcing member 24 provided across the longitudinal direction of the second base materials 16A and 16B and supporting a resin mirror (not shown), the second base material 16A, 16B and the second reinforcing member 26 that connects the first reinforcing members 24 to each other. By providing the reinforcing members 24 and 26 on the back surface of the resin mirror of the frame body 22, that is, on the resin support body side, the durability of the frame body 22 is further improved.
As will be described later, the form of the reinforcing member is not limited to this. For example, the reinforcing member 24 may include only the first reinforcing member 24 in FIG. 2, and may not include the first reinforcing member 24. You may have only the 2nd reinforcement member 26 which connects 2nd base materials directly. Further, two or more reinforcing members of various forms may be provided in combination.

FIG. 3 is a schematic view showing an example (frame body 28) of a third embodiment of a frame body used in the mirror unit of the present invention. In this embodiment, the resin body mirror fitted in the frame body 28 is shown. On the resin support body side, a plate-shaped reinforcing member 30 that is connected to the opposing second base materials 16A and 16B and closes the opening of the frame body 28 is further provided. Since the back surface of the resin mirror (not shown) of the frame body 28, that is, the resin support body side is covered with the plate-like reinforcing member 30, the frame body 28 and further the mirror unit including the frame body 28 are provided. Durability is further improved.
The shape of the reinforcing member is not limited to the above, and can take various forms as shown in the schematic plan views of FIGS. 4A to 4D. Although the example is given to the following, the shape of a reinforcement member is not limited to these.
FIG. 4A is a schematic plan view showing a frame body including a reinforcing member having a shape connected to the second base materials 16A and 16B of the frame body, and FIG. 4B is connected to the elongated first base material 18. FIG. 4C is a schematic plan view showing a frame provided with reinforcing members parallel to the opposing second base materials 16A and 16B, FIG. 4C is a schematic plan view showing a frame provided with lattice-shaped reinforcing members, and FIG. It is a schematic plan view which shows a frame provided with two reinforcement members which connect 2nd base materials 16A and 16B with an angle.

In any of the above embodiments, the resin mirror 14 is easily fitted into the frame body. For this reason, a plurality of mirror units are used, and one of the plurality of resin mirrors 14 in the plurality of mirror units is used. Even when the resin mirror of the part is damaged, only the damaged resin mirror 14 can be easily replaced in the corresponding mirror unit.
In addition, for the purpose of stably holding the resin mirror on the frame body of the mirror unit, it is also a preferable aspect to further include a resin mirror fixing member on the side of the frame body where the resin mirror is inserted. The fixing member is, for example, a member having the holding groove 20 and having the same shape as the first base material 18, and is fitted between the second base materials 16 </ b> A and 16 </ b> B so as to open the frame body 12. And the like.
Further, for the purpose of protecting the surface of the resin mirror 14, the openings on the light receiving surface side of the frames 12, 22, and 28 may be covered with a light transmissive cover.

When the frame, the first reinforcing member, the second reinforcing member, and the plate-like reinforcing member are formed of a metal such as stainless steel or aluminum, the contact surface of the resin mirror with the frame or the reinforcing member is heated. In order to prevent deformation due to the influence of the heat insulation layer, a heat insulating layer may be provided on the contact surface of the holding member provided on the frame and the resin mirror of the reinforcing member.
The heat insulating layer is not particularly limited as long as it has low thermal conductivity and good durability. For example, it is a layer composed of a resin material containing a large amount of air, such as urethane foam and polystyrene. It is preferable that
The thickness of the heat insulating layer is appropriately selected depending on the thermal conductivity of the material, but in general, it is preferably in the range of 1.0 mm to 10.0 mm.

[Resin mirror]
The resin mirror used in the mirror unit of the present invention has a metal reflective layer and a protective layer in this order on a resin support.
As the support for the resin mirror, a resin support represented by a polyester film such as a polyethylene terephthalate (PET) film that is inexpensive and excellent in mechanical strength is used, and the resin mirror has flexibility. In addition, a protective layer for blocking oxygen and ultraviolet rays is provided on the metal reflection layer in order to suppress deterioration of the resin material due to ultraviolet rays and reduction in reflectance due to oxidation of the metal reflection layer.

<Resin support>
The resin mirror of the present invention uses a resin support as a support. Resin which comprises a support body is not specifically limited, According to the objective, it selects suitably.
Examples of the resin constituting the support include polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; acrylic resins such as polymethyl methacrylate; polyamide resins; polyimides Polyvinyl chloride resin; Polyphenylene sulfide resin; Polyethersulfone resin; Polyethylene sulfide resin; Polyphenylene ether resin; Styrene resin; Cellulose resin such as cellulose acetate;
Of these, polyester resins and acrylic resins are preferred from the viewpoint of good transparency and weather resistance of the resin mirror.

In the present invention, the shape of the support is not particularly limited, and is appropriately selected depending on the intended use mode. The shape may be any one having a surface shape such as a sheet shape (planar shape), a diffusion surface, a concave surface, or a convex surface.
The thickness of the support is appropriately selected depending on the shape of the frame and the location of the resin mirror. When the support is planar, it is preferably 25 μm to 300 μm, more preferably 50 μm to 290 μm, and more preferably 50 μm to 250 μm is more preferable. The support in the present invention tends to improve the mechanical strength when the thickness is 25 μm or more, and is advantageous in terms of cost when the thickness is 300 μm or less.
By using such a resin support, the resin mirror according to the present invention achieves the required strength and durability without bonding to the metal substrate, and selects the thickness of the resin support. By doing so, a film mirror can also be made hard and can also be made flexible.
By setting the thickness of the resin support of the resin mirror to 80% or more with respect to the thickness of the resin mirror, the resin support can be used in this embodiment without being bonded to other substrates, among others. By setting the thickness of the resin support to 90% to 99% with respect to the thickness of the resin mirror, a resin mirror superior in self-supporting property can be obtained. Even if it is not bonded to the base material, it can be suitably used by being fitted into the frame body having the holding groove according to the present invention.

<Resin intermediate layer>
The resin mirror of the present invention has a metal reflective layer on a resin support, but has a resin intermediate layer between them for the purpose of improving the adhesion between the resin support and the metal reflective layer. Also good.
Examples of the resin intermediate layer include an easily adhesive layer for facilitating the adhesion of metal and a plating undercoat polymer layer useful for forming a metal reflective layer by a plating method, and these have a single layer structure. Alternatively, it may be composed of two or more layers.

[Easily adhesive layer]
In the present invention, an easy adhesion layer may be provided in order to improve the adhesion between the support and the metal reflective layer. In addition, when a plating undercoat polymer layer is provided on the easy adhesion layer, the easy adhesion layer improves the adhesion between the support and the plating undercoat polymer layer, resulting in adhesion between the support and the metal reflective layer. More improved.

In the present invention, the easy-adhesion layer contains the same resin as the resin constituting the support or a resin having an affinity for the resin constituting the support from the viewpoint of adhesion to the adjacent support. Is preferred.
The resin contained in the easy adhesion layer may be, for example, a thermosetting resin, a thermoplastic resin, or a mixture thereof. Examples of the thermosetting resin include an epoxy resin, a phenol resin, a polyimide resin, a polyester resin, a bismaleimide resin, and an isocyanate resin. Examples of the thermoplastic resin include polyolefin resin, phenoxy resin, polyether sulfone, polysulfone, polyphenylene sulfone, polyphenylene sulfide, polyphenyl ether, polyether imide, and the like.
The thermoplastic resin and the thermosetting resin may be used alone or in combination of two or more. The combined use of two or more resins is performed for the purpose of exhibiting a more excellent effect by compensating for the defects of the respective resins.

When the easy adhesion layer is provided between the plating undercoat polymer layer and the support, a functional group and a polymerizable group interacting with the plating catalyst or its precursor contained in the plating undercoat polymer layer described in detail below are provided. It is preferable to contain an active species that generates an active site capable of interacting with the polymer compound. Such an easy-adhesion layer is preferably, for example, a polymerization initiation layer containing a radical polymerization initiator or a polymerization initiation layer made of a resin having a functional group capable of initiating polymerization. More specifically, the easy adhesion layer is composed of a layer containing a polymer compound and a radical polymerization initiator, a layer containing a polymerizable compound and a radical polymerization initiator, or a resin having a functional group capable of initiating polymerization. A layer is preferred.
Examples of the layer made of a resin having a functional group capable of initiating polymerization include polyimides having a polymerization initiating site described in paragraphs [0018] to [0078] of JP-A-2005-307140 in the skeleton.

Furthermore, when forming an easy-adhesion layer, a compound having a polymerizable double bond, specifically an acrylate compound or a methacrylate compound, may be used in order to promote crosslinking in the layer. It is preferable to use those. In addition, as a compound having a polymerizable double bond, a part of a thermosetting resin or a thermoplastic resin such as an epoxy resin, a phenol resin, a polyimide resin, a polyolefin resin, a fluorine resin, etc. Alternatively, a (meth) acrylated resin using acrylic acid or the like may be used.

As long as the effects of the present invention are not impaired, the easy-adhesion layer in the present invention contains one or more various additives such as an adhesion-imparting agent, a silane coupling agent, an antioxidant, and an ultraviolet absorber as necessary. Two or more kinds may be added.
In general, the thickness of the easy-adhesion layer in the present invention is preferably in the range of 0.1 μm to 10 μm, and more preferably in the range of 0.2 μm to 5 μm.

[Plating undercoat polymer layer]
The plating undercoat polymer layer in the present invention has at least reduced metal particles and a plating undercoat polymer described later.
In a preferred embodiment of the present invention, a composition containing a metal precursor and a plating undercoat polymer described below is used to form a plating undercoat polymer layer containing the metal precursor on the support by a method such as coating, Alternatively, a layer is formed on a support using a composition containing a plating undercoat polymer described later, and then the composition containing a metal precursor is brought into contact with the layer provided on the support by a method such as immersion. To form a polymer layer containing a metal precursor. Thereafter, it is preferable to reduce the metal precursor contained in the plating undercoat polymer layer containing the metal precursor to form a plating undercoat polymer layer containing the reduced metal particles.

(Plating undercoat polymer)
First, the plating undercoat polymer used for forming the plating undercoat polymer layer will be described.
The plating undercoat polymer used for forming the plating undercoat polymer layer in the present invention has at least a polymerizable group and a functional group that interacts with the metal precursor (hereinafter referred to as “interactive group” as appropriate). .
The main skeleton of the plating undercoat polymer is preferably an acrylic polymer, polyether, acrylamide, polyamide, polyimide, polyester, or the like, but more preferably an acrylic polymer.
The plating undercoat polymer may contain a constitutional unit other than a constitutional unit containing a polymerizable group and an interaction group depending on the purpose. When a plating undercoat composition is formed by including a structural unit other than the structural unit containing a polymerizable group and a structural unit containing an interactive group (hereinafter referred to as other structural unit as appropriate), water or It is excellent in solubility in an organic solvent, and a uniform plating undercoat layer can be formed.

As a preferable embodiment of the plating undercoat polymer, an acrylic polymer having an acidic group and a polymerizable group as an interactive group in the side chain can be mentioned.
Hereinafter, a polymerizable group, an interactive group, and characteristics of the plating undercoat polymer will be described in detail.

-Polymerizable group-
The polymerizable group of the plating undercoat polymer forms a chemical bond between the polymers or between the polymer and the base layer (a support or an easy-adhesion layer or an undercoat layer provided on the support) by applying energy. Any functional group can be used. Examples of the polymerizable group include a radical polymerizable group and a cationic polymerizable group. Of these, a radical polymerizable group is preferable from the viewpoint of reactivity.
Examples of the radical polymerizable group include methacryloyl group, acryloyl group, itaconic acid ester group, crotonic acid ester group, isocrotonic acid ester group, maleic acid ester group, styryl group, vinyl group, acrylamide group and methacrylamide group. It is done. Among these, a methacryloyl group, an acryloyl group, a vinyl group, a styryl group, an acrylamide group, and a methacrylamide group are preferable, and from the viewpoint of radical polymerization reactivity and synthesis versatility, a methacryloyl group, an acryloyl group, an acrylamide group, and A methacrylamide group is preferable, and an acrylamide group and a methacrylamide group are more preferable from the viewpoint of alkali resistance.
Among them, various polymerizable groups introduced into the acrylic polymer include (meth) acryl groups such as (meth) acrylate groups or (meth) acrylamide groups, vinyl ester groups of carboxylic acids, vinyl ether groups, and allyl ether groups. A polymerizable group is preferred.

-Interactive groups-
The interaction group of the plating undercoat polymer is a functional group that interacts with the metal precursor (for example, a coordination group, a metal ion adsorbing group, etc.), and can form an electrostatic interaction with the metal precursor. A functional group, or a nitrogen-containing functional group, a sulfur-containing functional group, an oxygen-containing functional group or the like that can form a coordination with a metal precursor can be used.
More specifically as an interactive group, amino group, amide group, imide group, urea group, triazole ring, imidazole group, pyridine group, pyrimidine group, pyrazine group, triazine group, piperidine group, piperazine group, pyrrolidine group, Nitrogen-containing functional groups such as pyrazole group, group containing alkylamine structure, cyano group, cyanate group (R—O—CN); ether group, hydroxyl group, phenolic hydroxyl group, carboxyl group, carbonate group, carbonyl group, ester group, Oxygen-containing functional groups such as groups containing N-oxide structures, groups containing S-oxide structures, groups containing N-hydroxy structures; thiophene groups, thiol groups, thiourea groups, sulfoxide groups, sulfonic acid groups, sulfonic acid ester structures Sulfur-containing functional groups such as groups containing phosphine groups; Phosphorus-containing functional groups such as those containing ester structure; chlorine, such as group containing a halogen atom such as bromine may be mentioned as an example, the functional group capable of having a salt structure can also be used the salts thereof.
The interactive group may be a non-dissociative functional group or an ionic polar group, and these may be contained at the same time, but an ionic polar group is preferred.

As the interactive group composed of an ionic polar group, among the above-mentioned interactive groups, the plating undercoat polymer support (in the case where the easy-adhesion layer is formed on the support, the easy-adhesion layer) is used. From the viewpoint of adhesion, carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, and boronic acid groups are preferred, and in particular, they have moderate acidity (does not decompose other functional groups) and affect other functional groups. Carboxylic acid groups are particularly preferred from the viewpoints of less concern, excellent compatibility with the plating layer, and easy availability of raw materials.

An ionic polar group such as a carboxylic acid group can be introduced into the plating undercoat polymer by copolymerizing a radical polymerizable compound having an acidic group.
Hereinafter, regarding the preferred constitution of the plating undercoat polymer used in the present invention, as a polymer having an interactive group comprising a radically polymerizable group and a non-dissociable functional group, paragraph [0106] of JP-A-2009-007540 is disclosed. ] To [0112] can be used. As the polymer having a radical polymerizable group and an interactive group composed of an ionic polar group, polymers described in paragraphs [0065] to [0070] of JP-A-2006-135271 can be used. Examples of the polymer having a radical polymerizable group, an interactive group composed of a non-dissociative functional group, and an interactive group composed of an ionic polar group include paragraphs [0010] to [0010] of JP 2010-248464 A. [0128] Polymers described in paragraphs [0030] to [0108] of JP 2010-84196 A and US Patent Application Publication No. 2010-080964 may be used.

It should be noted that the metal precursor described later may be applied after the formation of the plating undercoat polymer layer, or may be contained in the composition for the plating undercoat polymer layer from the beginning. When the metal precursor is contained in the composition for forming a plating undercoat polymer layer, the content of the metal precursor is preferably 0.5% by mass to 100% by mass with respect to the total amount of the composition, and 1% by mass to 50%. The mass% is more preferable.

The plating undercoat polymer layer preferably contains a radical polymerization initiator such as a photopolymerization initiator or a thermal polymerization initiator in order to increase sensitivity to energy application. The radical polymerization initiator is not particularly limited, and generally known ones are used.
However, when energy is applied, the plating undercoat polymer can generate an active site that interacts with the support or the easy-adhesion layer, that is, when a polymer having a polymerization initiation site in the above-described polymer skeleton is used. It is not necessary to add these radical polymerization initiators.

The amount of the radical polymerization initiator to be contained in the plating undercoat polymer layer forming composition is selected according to the configuration of the plating undercoat polymer layer forming composition, but in general, the plating undercoat polymer layer forming composition. The content is preferably about 0.05% by mass to 30% by mass, and more preferably about 0.1% by mass to 10.0% by mass.

The plating undercoat polymer layer is formed by applying a composition for forming a polymer layer containing a plating undercoat polymer on the resin support or an easy-adhesion layer formed on the surface of the support and applying energy. be able to.
When the plating undercoat polymer layer is directly provided on the resin support, it is preferable to perform an easy adhesion treatment such as applying energy to the surface of the support in advance.
The method for providing the polymer layer on the support is not particularly limited, and a method of immersing the support in a polymer layer forming composition containing a plating undercoat polymer or a polymer layer forming composition containing a plating undercoat polymer is used as a support. An example is a method of coating on top. From the viewpoint of easily controlling the thickness of the resulting polymer layer, a method of applying a polymer layer forming composition containing a plating undercoat polymer on a support is preferred.

Plating coating amount of the polymer layer forming composition containing undercoat polymer, from the viewpoint of sufficient interaction formed with the later-described metal precursor, preferably from ^{0.05g / m 2 ~ 10g / m} 2 on a solid basis In particular, 0.3 g / m ² to 5 g / m ² is preferable.
The coating solution of the composition for forming a polymer layer containing a plating undercoat polymer applied to a support or the like is dried at 20 ° C. to 60 ° C. for 1 second to 2 hours, and then dried at a temperature exceeding 60 ° C. for 1 second to 2 hours. More preferably, after drying at 20 ° C. to 60 ° C. for 1 second to 20 minutes, it is more preferable to dry at a temperature exceeding 60 ° C. for 1 second to 20 minutes.

The composition for forming a polymer layer containing a plating undercoat polymer has a polymer in an energy application region by applying energy after contacting the support or the easy adhesion layer provided on the support. An interaction is formed between the polymerizable groups or the polymerizable group of the polymer and the support or the easy-adhesion layer provided on the support. A fixed polymer layer is formed on the support via the adhesive layer. Thereby, a support body and a polymer layer adhere | attach firmly.

Examples of the energy application method include heating and exposure.
As an energy application method by exposure, specifically, light irradiation by a UV lamp, visible light, or the like is possible. Examples of the light source used for exposure include a mercury lamp, a metal halide lamp, a xenon lamp, and a chemical lamp. Examples of radiation include electron beams, X-rays, ion beams, and far infrared rays. Also, g-line, i-line, deep-UV light, and high-density energy beam (laser beam) are used.
Exposure power, in order to polymerize the easily proceed, and because to suppress the decomposition of the polymer, or within the range for the polymer to form a good interaction, from the viewpoint of ^{10mJ / cm 2 ~ 8000mJ / cm} 2 it is ^preferably, and more preferably in a range of 100mJ / cm 2 ~ 3000mJ / cm 2.
Note that exposure may be performed in an atmosphere in which substitution with an inert gas such as nitrogen, helium, or carbon dioxide is performed, and the oxygen concentration is suppressed to 600 ppm or less, preferably 400 ppm or less.

Energy application by heating can be performed by, for example, a general heat heat roller, laminator, hot stamp, electric heating plate, thermal head, laser, blower dryer, oven, hot plate, infrared dryer, heating drum, or the like.
In addition, when energy is applied by heating, the temperature is preferably in the range of 20 ° C. to 200 ° C. in order to facilitate the polymerization and to suppress thermal denaturation of the support, and is preferably 40 ° C. More preferably, it is in the range of ˜120 ° C.

After energy application, a step of removing unreacted polymer may be provided as appropriate.
The film thickness of the plating undercoat polymer layer is not particularly limited, but is preferably 0.05 μm to 10 μm, more preferably 0.3 μm to 5 μm from the viewpoint of adhesion to a support or the like.
Further, the surface roughness (Ra) of the polymer layer obtained by the above method is preferably 20 nm or less, more preferably 10 nm or less, from the viewpoint of reflection performance.

The plating undercoat polymer layer in the present invention contains reduced metal particles. Reduced metal particles contained in the plating undercoat polymer layer are obtained by applying a metal precursor to the plating undercoat polymer layer and reducing the metal precursor to make the metal precursor reduced metal particles. It is done. When the metal precursor is applied to the plating undercoat polymer layer, the metal precursor adheres to the interactive group by interaction.

The metal precursor used in the present invention is not particularly limited as long as it functions as an electrode by changing to a metal by a reduction reaction. Moreover, as a metal precursor, what functions as an electrode of plating in formation of a metal reflective layer is mentioned as a preferable example. Therefore, what functions as an electrode by reducing a metal precursor to a metal is preferable.
Specifically, metal ions such as Au, Pt, Pd, Ag, Cu, Ni, Al, Fe, and Co are used. Metal ions that are metal precursors are contained in a composition containing a plating undercoat polymer (a composition for forming a plating undercoat polymer layer). After forming a layer on the support, zero-valent metal particles are formed by a reduction reaction. It becomes.
It is preferable that the metal ion which is a metal precursor is contained in the composition for forming a plating undercoat polymer layer as a metal salt.
As the metal ion, Ag ion, Cu ion, and Pd ion are preferable in terms of the type and number of functional groups capable of coordination, and catalytic ability.
As the Ag ions, those obtained by dissociating the silver compounds shown below can be suitably used. Specific examples of the silver compound include silver nitrate, silver acetate, silver sulfate, silver carbonate, silver cyanide, silver thiocyanate, silver chloride, silver bromide, silver chromate, silver chloranilate, silver salicylate, silver diethyldithiocarbamate, Examples thereof include silver diethyldithiocarbamate and silver p-toluenesulfonate. Among these, silver nitrate is preferable from the viewpoint of water solubility.
When Cu ions are used, those obtained by dissociating copper compounds as shown below can be suitably used. Specific examples of copper compounds include copper nitrate, copper acetate, copper sulfate, copper cyanide, copper thiocyanate, copper chloride, copper bromide, copper chromate, copper chloranilate, copper salicylate, copper diethyldithiocarbamate, diethyldithiol. Examples thereof include copper carbamate and copper p-toluenesulfonate. Among these, copper sulfate is preferable from the viewpoint of water solubility.

The metal precursor is preferably applied to the plating undercoat polymer layer as a dispersion or solution (metal precursor liquid).
As an application method, for example, a metal precursor is contained in the form of a dispersion or a solution in a composition containing a plating undercoat polymer, and this composition is formed on a support or an easy-adhesion layer provided on the support. A method of forming a coating undercoat polymer layer by coating, forming a polymer layer on a support or an easy-adhesion layer provided on the support using a composition containing a plating undercoat polymer, and then on the polymer layer After forming a polymer layer on a support or on an easy-adhesion layer provided on the support using a composition containing a metal precursor and a composition (dispersion or solution), and a composition containing a plating undercoat polymer And a method in which the support on which the polymer layer is formed is immersed in a composition (dispersion liquid or solution) containing a metal precursor, and the method for applying the metal precursor is easy to control. Is preferred
When the dispersion is used for applying the metal precursor to the plating undercoat polymer layer, the particle diameter of the metal precursor in the dispersion is preferably 1 nm to 200 nm, more preferably 1 nm to 100 nm, and preferably 1 nm to 60 nm. Further preferred. By setting this particle size, the particle size of the reduced metal particles can be controlled to a desired size.
Here, the particle diameter is an average primary particle diameter (volume conversion), and is read from an image of SEM (S-5200, manufactured by Hitachi High-Tech Manufacturing & Service Co., Ltd.).

Metal ions, which are metal precursors applied to the plating undercoat polymer layer, are reduced with a metal activation liquid (reducing liquid). The metal activation liquid is composed of a reducing agent that can reduce a metal precursor (mainly metal ions) to a zero-valent metal and a pH adjuster for activating the reducing agent.
The concentration of the reducing agent with respect to the entire metal activation liquid is preferably 0.05% by mass to 50% by mass, and more preferably 0.1% by mass to 30% by mass.
As the reducing agent, boron-based reducing agents such as sodium borohydride and dimethylamine borane, and reducing agents such as formaldehyde and hypophosphorous acid can be used. In particular, reduction with an aqueous alkaline solution containing formaldehyde is preferred.

The concentration of the pH adjusting agent with respect to the entire metal activation liquid is preferably 0.05% by mass to 10% by mass, and more preferably 0.1-5% by mass.
As the pH adjuster, acetic acid, hydrochloric acid, sulfuric acid, nitric acid, sodium hydrogen carbonate, aqueous ammonia, sodium hydroxide, potassium hydroxide and the like can be used.
The temperature during the reduction is preferably 10 ° C to 100 ° C, more preferably 20 ° C to 70 ° C.
These concentrations and temperature ranges are preferable from the viewpoints of the particle diameter of the metal precursor, the surface roughness of the polymer layer, the conductivity (surface resistance value), and the deterioration of the reducing solution during reduction.

The particle diameter of the reduced metal particles contained in the plating undercoat polymer layer is preferably 1 nm to 200 nm, more preferably 1 nm to 100 nm, and still more preferably 1 nm to 60 nm from the viewpoint of reflection performance. When the particle diameter of the metal particles is within this range, the reflectance after plating becomes good.
Here, the particle diameter is a value read from an SEM (S-5200 manufactured by Hitachi High-Tech Manufacturing & Service) image.

The surface resistance value of the plating undercoat polymer layer containing the reduced metal particles is preferably 0.001Ω / □ or more and 100Ω / □ or less, and more preferably 0.03Ω / □ or more and 50Ω / □ or less. When the surface resistance value of the plating undercoat polymer layer is within this range, the plating surface is formed uniformly and smoothly and the reflectance is good.
Further, the surface roughness (Ra) of the plating undercoat polymer layer containing the reduced metal particles is preferably 20 nm or less, and more preferably 10 nm or less, from the viewpoint of reflection performance.
The plating undercoat polymer layer containing the metal particles thus obtained is suitably used when a metal reflective layer described in detail below is formed by a plating method that is a wet method, and plating is performed using the plating undercoat polymer layer. The metal reflective layer formed by the method is excellent in adhesion to the resin support and surface smoothness.

<Metal reflective layer>
The metal reflective layer in the present invention is provided directly on the resin support, or is provided via the above-described resin intermediate layer provided as desired.
The material for forming the metal reflection layer is not particularly limited as long as it is a metal material that reflects visible light and infrared light, and examples thereof include silver and aluminum. From the viewpoint of light reflection performance, silver or an alloy containing silver is preferable. Silver or an alloy containing silver can increase the reflectance in the visible light region of the resin mirror and reduce the dependency of the reflectance on the incident angle. The visible light region means a wavelength region of 400 nm to 700 nm. Here, the incident angle means an angle with respect to a line perpendicular to the film surface. As a silver alloy, other metals such as gold, palladium, copper, nickel, iron, gallium, and indium are used to the extent that the durability of the silver-containing metal layer is improved and the reflective properties of the metal reflective layer are not affected. One or more metals selected from the group consisting of titanium, and bismuth may be included, and it is also a preferred embodiment to use an alloy made of silver and other metals. As the silver alloy, an alloy of silver and one or more metals selected from gold, copper, nickel, iron, and palladium is particularly preferable from the viewpoints of moist heat resistance, reflectance, and the like.

For example, when the metal reflective layer is a film made of a silver alloy, the silver content is 90 atomic percent to 99.8 atomic percent in the total (100 atomic percent) of silver and other metals in the metallic reflective layer. preferable. Further, the content of other metals is preferably 0.2 atomic% to 10 atomic% from the viewpoint of durability.

The surface roughness (Ra) of the metal reflective layer in the present invention is preferably 20 nm or less, more preferably 10 nm or less, and further preferably 5 nm or less. By setting it within this range, the reflectance of the obtained resin mirror is improved, and sunlight can be collected efficiently.

The method for forming the metal reflective layer in the present invention is not particularly limited, and either a wet method or a dry method may be employed.
Examples of the wet method include an electroplating method.
Examples of the dry method include a vacuum deposition method, a sputtering method, and an ion plating method.

Hereinafter, a case where the metal reflective layer is formed by electroplating will be described.
A conventionally known method can be used as the electroplating method.
In the present invention, since the metal particles contained in the plating undercoat polymer layer have a function as an electrode, by performing electroplating on the plating undercoat polymer layer, metal reflection excellent in adhesion to the resin support is achieved. A layer can be formed.
Examples of metal compounds used for plating include silver nitrate, silver acetate, silver sulfate, silver carbonate, silver methanesulfonate, silver ammonia, silver cyanide, silver thiocyanate, silver chloride, silver bromide, silver chromate, and chloranil. Examples thereof include silver compounds such as silver oxide, silver salicylate, silver diethyldithiocarbamate, silver diethyldithiocarbamate, and silver p-toluenesulfonate. Among these, silver methanesulfonate is preferable from the viewpoint of environmental impact and smoothness.

In addition, between the plating undercoat polymer layer and the metal reflective layer, for example, a metal layer containing another metal such as copper, nickel, chromium, iron, or the like may be provided as a base metal layer.
Moreover, the film thickness of the metal reflective layer obtained by electroplating can be controlled by adjusting the metal concentration or current density contained in the plating bath. By adding a base metal layer having an appropriate thickness, it is possible to improve reflectance and reduce pinholes by smoothing the surface.
The film thickness of the metal reflective layer is 0.05 μm to 2.0 μm from the viewpoint of forming a reflective film without pinholes and not forming irregularities that scatter light on the surface of the metal reflective layer. Preferably, it is 0.08 μm to 0.5 μm.

In the present invention, the metal reflective layer may be formed by dry plating such as vacuum deposition using a plating undercoat polymer layer containing reduced metal particles. According to this method, since the surface of the plating undercoat polymer layer is covered with metal, it is possible to form a metal reflective layer that has better adhesion than normal vapor deposition and is strong against heat.

After electroplating, the metal reflective layer may be treated with a strong acid, strong alkali, or the like in order to improve the reflection performance and durability of the metal reflective layer. Further, an inorganic film or a metal oxide film may be formed on the metal surface. Moreover, you may provide the discoloration prevention agent layer containing a discoloration prevention agent.
The anti-discoloring agent layer functions to prevent discoloration of the metal reflective layer. Examples of the discoloration inhibitor include thioether, thiol, Ni organic compound, benzotriazole, imidazole, oxazole, tetrazaindene, pyrimidine, thiadiazole and the like.
The anti-discoloring agent layer is broadly classified, and those having an adsorbing group that adsorbs metals and antioxidants are preferably used.

<Protective layer>
In the resin mirror of the present invention, in order to stabilize the specularity by preventing deterioration or breakage of the metal reflective layer, resin support, or plating undercoat polymer layer provided as desired by sunlight, rainwater, dust, etc. Further, a protective layer is provided on the surface on the incident light side of the metal reflective layer described in detail below.
〔resin〕
The protective layer in the present invention preferably contains a resin. The resin material used for forming the protective layer is a resin capable of forming a film or layer, and the strength or durability of the formed film or layer, air and moisture blocking properties, and further adjacent to the protective layer In addition to the adhesion to the layer to be applied, for example, the metal reflective layer and the surface coating layer, a resin having transparency, particularly high transparency to light having a wavelength required by the resin mirror is preferable.

Specifically, for example, cellulose ester resins, polycarbonate resins, polyarylate resins, polysulfone (including polyether sulfone) resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, and olefins such as polyethylene and polypropylene Resin, cellulose diacetate resin, cellulose triacetate resin, cellulose acetate propionate resin, cellulose acetate butyrate resin, polyvinyl alcohol, polyvinyl butyral, ethylene vinyl alcohol resin, ethylene vinyl acetate resin, and ethylene acrylate copolymer, Polycarbonate, norbornene resin, polymethylpentene resin, polyamide, fluorine resin, polymethyl methacrylate, acrylic Fat, polyurethane resin, silicone resin or the like.
Among these, from the viewpoint of adhesion between the protective layer and the metal reflective layer, the resin contained in the protective layer is selected from acrylic resin, polyvinyl butyral, ethylene vinyl acetate resin, and ethylene acrylate copolymer. One or more resins are preferred.

[Crosslinking agent]
The protective layer according to the present invention preferably further contains a crosslinking agent. By containing a cross-linking agent, the cross-linked structure is formed in the protective layer, so that the strength is further improved, and further, the adhesion with the adjacent metal reflective layer is further improved. .
The crosslinking agent can be selected in consideration of the relationship with the resin constituting the protective layer, and examples thereof include carbodiimide compounds, isocyanate compounds, epoxy compounds, oxetane compounds, melamine compounds, bisvinylsulfone compounds, and the like. From this point of view, at least one crosslinking agent selected from the group consisting of a carbodiimide compound, an isocyanate compound, and an epoxy compound is preferable.
In addition to the above components, the protective layer contains additives such as an ultraviolet absorber, a photopolymerization initiator, an antistatic agent, a coating aid (leveling agent), an antioxidant, and an antifoaming agent. Also good.

The method for forming the protective layer in the present invention is not particularly limited, and the method for forming the protective layer by dissolving the protective layer-forming composition in a solvent and applying the solution on the metal reflective layer, and then removing the solvent. A method of forming a protective layer by heating to a temperature at which the resin contained in the protective layer-forming composition melts and casting on the metal reflective layer, and forming the film in advance using the protective layer-forming composition Examples of the method include forming the protective layer by a method such as bonding the obtained film to the metal reflective layer via an adhesive or fusing the metal reflective layer by a method such as thermal lamination. It is done.

From the viewpoint of uniformly forming a protective layer having excellent adhesion, the solid content concentration of the coating liquid composition for forming a protective layer is preferably in the range of 1% by mass to 30% by mass.
The method of curing the resin film applied to the surface of the metal reflective layer is not particularly limited, and a method according to the resin material used for forming the protective layer, such as heating or UV irradiation, may be appropriately selected.

The film thickness of the protective layer is preferably in the range of 3 μm to 30 μm from the viewpoint of achieving the necessary protective function and durability and suppressing the reduction in light reflectivity, and in the range of 5 μm to 10 μm. It is more preferable that

<Surface coating layer>
The resin mirror according to the present invention may further have a surface coating layer on the protective layer. By having the surface coating layer, the weather resistance and scratch resistance of the resin mirror are further improved. A known resin layer or the like can be arbitrarily used as long as the surface coating layer is present on the surface of the protective layer and can prevent physical or chemical damage on the surface of the resin mirror.
That is, the surface coating layer may be a soft layer having a hardness of 100 N / mm ² or less and an elastic recovery rate of 60% or more, and is a so-called hard coat layer having a hard surface. Also good.
The thickness in the case of forming a soft surface coating layer is not particularly limited, but it is preferably 1 μm to 50 μm because the scratch resistance of the resin mirror becomes better, and the haze value and the reflectance maintenance factor become higher. It is preferably 3 μm to 30 μm.
In addition, the thickness in the case of forming a hard surface coating layer is preferably 0.1 μm to 50 μm, more preferably 0.1 μm to 10 μm from the viewpoint of antifouling properties and scratch resistance.

The thickness of the resin mirror may be practically 0.1 mm or more, but is preferably 0.2 mm to 5.0 mm from the viewpoint of good strength, durability, and workability.

<Physical properties of resin mirror>
The resin mirror used in the present invention preferably has a heat shrinkage ratio of 0.6% or less, more preferably 0.5% or less when heat-treated at 150 ° C. for 30 minutes. The resin mirror according to the present invention is less likely to be deformed by heat and has a stable specularity. Therefore, even when the resin mirror is left outdoors for a long period of time, it functions as a resin mirror (such as sunlight collection). Can be fully demonstrated. In particular, it is also suitable for use in deserts where the temperature difference between day and night is large.
The thermal contraction rate of the resin mirror according to the present invention can be controlled by the drying temperature condition when forming the resin intermediate layer (the easy adhesion layer and / or the plating undercoat polymer layer). For example, when the resin intermediate layer is dried at a high temperature, the thermal shrinkage rate of the formed resin mirror can be lowered.
In addition, this thermal contraction rate is a value obtained by the following method.

A resin mirror having a width of 10 mm and a length of 500 mm marked with an interval of about 100 mm is heat-treated for 30 minutes under the conditions of a temperature of 150 ° C. and a load of 0.5 g (conforming to JIS-C2318 (2007)). Then, the gap between the marked lines before and after the heat treatment is measured using a heat shrinkage measuring instrument (AMM-1 machine, manufactured by Technone Corp.). Based on the obtained value, the thermal contraction rate (%) is calculated by the following formula.
Thermal shrinkage (%) = {(L ₀ −L) / L ₀ } × 100
L ₀ : Gauge gap before heat treatment (mm)
L: Mark gap after heat treatment (mm)

The resin mirror used in the present invention may be flexible. By having flexibility, for example, it is possible to fit into a frame curved in a convex shape on the resin support side, and a concave mirror-like resin mirror can be formed.
The flexibility of the resin mirror in the present invention refers to stress, for example, when one end of a resin mirror sample having a width of 100 mm and a length of 300 mm is fixed and a force of 50 N / m is applied to the other end in the vertical direction. Deformation of 10 mm or more.

<Sunlight reflector>
The sunlight reflecting plate of the present invention is produced using the mirror unit of the present invention, and is formed by arranging a plurality of mirror units.
Although the mirror unit of the present invention can be used alone or for collecting sunlight, it is preferable to arrange a plurality of mirror units to efficiently collect sunlight.
By providing the frame of the mirror unit of the present invention with a solar light tracking system for tracking the mirror unit in the diurnal motion of the sun, it is possible to realize more efficient collection of sunlight.
Since the mirror unit of the present invention has a very excellent frame body and can easily mount or replace the film mirror used for sunlight reflection, the solar reflector using the mirror unit of the present invention. Is good not only in durability but also in maintainability. Therefore, the solar reflector produced using the mirror unit of the present invention is particularly suitable for photovoltaic power generation.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[Production of film mirror]
<Example 1>
On a polyethylene terephthalate (PET) film (Toyobo Co., Ltd., Cosmo Shine A-4300, thickness: 120 μm), a silver-containing metal reflective layer was provided by electroplating according to the following steps.
(Formation of silver-containing metal reflective layer)
(Formation of easy adhesion layer)
One surface of the PET film was subjected to corona discharge treatment under the condition of 730 J / m ² , and then the following easy-adhesion layer forming coating solution was applied by a bar coating method so that the dry weight was 124 mg / m ^2. did. And this was dried at 180 degreeC for 1 minute, and the easily bonding layer was formed.

-Composition of coating solution for easy adhesion layer formation-
・ Polyester resin water dispersion (Vylonal 1245, solid content: 30% by mass, manufactured by Toyobo Co., Ltd .... Binder) 48 parts by mass ・ PMMA resin fine particles (MP-1000, solid content: 100% by mass, Soken Chemical Co., Ltd.) ) Made ... mat material 0.5 parts by mass-Oxazoline compound (Epocross WS-700, solid content: 25% by mass, manufactured by Nippon Shokubai Co., Ltd., cross-linking agent) 3 parts by mass-Carbodiimide compound (Carbodilite V) -02-L2, solid content: 40% by mass, manufactured by Nisshinbo Co., Ltd., 17 parts by mass polyoxyalkylene alkyl ether (Naroacty CL-95, solid content: 100% by mass, Sanyo Chemical Industries, Ltd. ) Made)
0.15 parts by mass

(Formation of plating undercoat polymer layer)
The plating undercoat polymer layer coating solution prepared by the following method is applied to the easy-adhesion surface of the PET film on which the easy-adhesion layer has been formed by the bar coating method so that the film thickness after drying is about 0.55 μm. After drying at 25 ° C. for 10 minutes and at 80 ° C. for 5 minutes, UV exposure (wavelength: 254 nm, UV exposure: 1000 mJ / mm) using a UV irradiation device (UV lamp: metal halide lamp, manufactured by GS Yuasa). cm ² ). Next, the UV-exposed PET film was immersed in a 1% by mass aqueous sodium hydrogen carbonate solution for 5 minutes, and then washed by pouring with pure water for 1 minute to remove unreacted polymer.

-Preparation of coating solution for plating undercoat polymer layer formation-
In a mixed solution of acrylic polymer 1 (7 parts by mass), 1-methoxy-2-propanol (74 parts by mass), and water (19 parts by mass) having the following structure, a photopolymerization initiator (Esacure KTO-46, manufactured by Lamberdy) ) (0.35 parts by mass) was added and stirred to prepare a solution of a plating undercoat polymer (acrylic polymer 1).

 

 

(Give metal precursor)
As a solution containing a metal precursor, a 1% by mass aqueous solution of silver nitrate was prepared. The PET film coated with the plating undercoat polymer obtained above was immersed in a 1% by mass aqueous silver nitrate solution adjusted to 25 ° C. for 5 minutes, and then washed by pouring with pure water for 1 minute to obtain a metal precursor. The body was given.

(Reduction of metal precursor)
As a reducing solution, a 0.25 mass% formaldehyde aqueous solution containing 0.14 mass% sodium hydroxide was prepared. The PET film provided with the metal precursor obtained above is immersed in the reducing solution whose temperature is adjusted to 25 ° C. for 1 minute, and then washed by pouring with pure water for 1 minute to reduce the metal precursor. did.
When the surface resistance value after the reduction was measured using a surface resistance meter, it was about 10Ω / □. Moreover, when the surface roughness (Ra) was measured using an atomic force microscope (AFM), it was about 7 nm. Furthermore, when the particle diameter of the metal after reduction was measured using a scanning electron microscope (SEM), it was about 50 nm.

(Electroplating)
As a pre-treatment for electroplating, Dyne Cleaner AC100 (manufactured by Daiwa Kasei Co., Ltd.) whose temperature was adjusted to 25 ° C. with the PET film having the plated undercoat polymer layer containing the reduced metal particles obtained above on the surface. After being immersed in a 10% by mass aqueous solution for 30 seconds, it was washed several times. Subsequently, as a pretreatment for electroplating, it was immersed in a 10% by mass aqueous solution of Dyne Silver ACC (main component: methanesulfonic acid, manufactured by Daiwa Kasei Co., Ltd.) for 10 seconds and then washed several times.
Next, Dyne Silver Bright PL50 (main component: silver methanesulfonate, manufactured by Daiwa Kasei Co., Ltd.) adjusted to pH 9.0 with 8M potassium hydroxide was prepared as an electroplating solution. Then, a PET film having a plating undercoat polymer layer containing the reduced metal particles on the surface was immersed in this electroplating solution, and plated at 0.5 A / dm ^{2 for} 20 seconds.
As a post-treatment of electroplating, the plated PET film was immersed in a 10% by mass aqueous solution of Dyne Silver ACC (trade name: manufactured by Daiwa Kasei Co., Ltd.) for 90 seconds and then washed several times.
The surface roughness (Ra) after the post-plating treatment was measured using an atomic force microscope (AFM) and found to be about 4 nm.

(Preparation of protective layer)
On the plated surface of the metal reflective layer obtained above, acrylic resin (Harus Hybrid UV-G, trade name: manufactured by Nippon Shokubai Co., Ltd.) has a thickness after drying as shown in Table 1 below. The film mirror (resin mirror which concerns on this invention) which has the protective layer of the film thickness of following Table 1 was manufactured by apply | coating like this and drying at 80 degreeC for 1 minute.

A flat frame body 12 having the shape shown in FIG. 1A and having an inner dimension of 510 mm × 510 mm was made of aluminum A5052. A frame having the shape shown in FIG. 1A according to the present embodiment is described as “I” in Table 2.
The film mirror (resin mirror) 14 was fitted into the frame body 12 to obtain a mirror unit of Example 1.
<Examples 2 to 5>
Except that the thickness of the resin mirror was changed as shown in Table 1, mirror units of Examples 2 to 5 were obtained in the same manner as Example 1.
<Example 6>
A mirror unit of Example 6 was obtained in the same manner as in Example 1 except that a commercially available film mirror (manufactured by 3M, DMF1100) was used instead of the resin mirror used in Example 1.
<Example 7>
Instead of the resin mirror used in Example 1, a mirror unit of Example 7 was obtained in the same manner as in Example 1 except that a commercially available film mirror (manufactured by Refrac Tech, MirrorFilm) was used.
<Examples 8 to 13>
The thickness and configuration of the resin support used for the resin mirror are changed as shown in Table 1, and the mirror units of Examples 8 to 13 are used in the same manner as in Example 1 except that the frame 22 having the shape shown in FIG. 2 is used. Got. Note that the frame body having the shape shown in FIG. 2 according to the present embodiment is described as “II” in Table 2.
In Example 10, the light receiving surface of the resin mirror is curved in a concave shape so that the pair of second base materials 16A and 16B and the first reinforcing member 24 of the frame body 22 shown in FIG. 2 have a curvature radius of 10 m. It was configured as follows.

<Comparative Example 1>
A biaxially stretched polyester film (polyethylene terephthalate film, thickness 100 μm) was used as the resin support, and a polyester resin (Polyester SP-181, manufactured by Nippon Gosei Kagaku), a melamine resin (Super Becamine J-) was used on the surface. 820, manufactured by DIC Corporation), TDI isocyanate (2,4-tolylene diisocyanate), HDMI isocyanate (1,6-hexamethylene diisocyanate) at a resin solid content ratio of 20: 1: 1: 2, A resin mixed in toluene so as to have a concentration of 10% was coated by a gravure coating method to form an adhesive layer having a thickness of 0.1 μm.
Further, silver was formed into a thickness of 80 nm on this adhesive layer by vacuum vapor deposition to form a metal reflective layer.
A resin containing 20% by mass of rubber particles having an average particle diameter of 5 μm mixed with an acrylic resin and TDI (tolylene diisocyanate) isocyanate at a resin solid content ratio of 10: 2 on a metal reflective layer by a gravure coating method. A resin protective layer was formed by coating with a thickness of 75 μm. Mercaptoacetate (Glycol dimercaptoacetate) was added to the resin protective layer as a corrosion inhibitor so as to be 0.3 g / m ² .
A film mirror was produced by laminating an adhesive layer using a laminating agent and a release sheet using an acrylic film on the surface of the resin support that does not have a metal reflective layer.
Thereafter, the resin mirror prepared by attaching the adhesive layer exposed by peeling off the release sheet of the film mirror to an aluminum base material having a thickness of 475 μm as a supporting base material is used as the frame body 12 used in Example 1. The mirror unit of Comparative Example 1 was obtained.

Incidentally, Comparative Example 1 uses a mirror described in an example of Japanese Patent Application Laid-Open No. 2012-153036, in which a film mirror is bonded to an aluminum substrate.

[Evaluation]
The mirror units of Examples 1 to 13 and Comparative Example 1 produced above were evaluated according to the following criteria. These results are shown in Table 3.
<Mountability and exchangeability>
The mountability and exchangeability were evaluated based on the time taken to attach and replace the resin mirror and the yield rate (defect occurrence rate) as criteria.
A: Can be installed and replaced within 5 minutes, yield rate is 99% or more (resin occurrence rate is less than 1%, such as resin mirror distorted, bent, wrinkles, etc.)
B: Can be mounted and replaced within 5 minutes, but the yield rate is less than 90-99% (the rate of defects such as resin mirrors distorted, bent, wrinkles, etc. during mounting is higher than 1% but not higher than 10%)
C: It takes 5 minutes or more for installation and replacement, and the yield rate is 90% to less than 99%.
D: It takes 5 minutes or more for installation and replacement, and the yield rate is less than 90%.

<Temperature cycle>
The temperature cycle test of each of the prepared mirrors was conducted by evaluating the surface of the resin mirror after 8000 times of standing at −40 ° C. for 30 minutes and standing at 65 ° C. for 30 minutes according to the following criteria. did. In addition, a high power constant temperature and humidity chamber ARL-1100-J manufactured by ESPEC was used for the test.
A: Surface defects such as wrinkles and swells do not occur.
B: Slight waviness and undulation occurred. When the object is projected on the reflecting mirror, a slight fluctuation of the image can be confirmed locally.
C: Moderate wrinkles and undulations occur on the surface. When the object is projected on the reflector, the image clearly shows the fluctuation.
D: Wrinkles and undulations are remarkably generated on the surface, and the entire film is greatly distorted. It cannot be used as a reflector.

 

 

All the mirror units of the present invention were excellent in wearability and exchangeability, and had good durability. On the other hand, the mirror unit of Comparative Example 1 using a resin mirror with a film mirror attached to an aluminum substrate is inferior in handleability, has a low yield rate, and deteriorates due to a temperature cycle to obtain sufficient reflection performance. I couldn't.

The entire disclosure of Japanese Patent Application No. 2013-062567 filed on March 25, 2013 is incorporated herein by reference. All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually described to be incorporated by reference, Incorporated herein by reference.

Claims (13)

A long first base material;
A long second base material extending in parallel from both longitudinal ends of the first base material, and a frame body,
Holding grooves formed in the longitudinal direction along the inner surface of the frame,
A resin mirror having a metal reflective layer and a protective layer in this order on a resin support fitted and fitted in the holding groove,
Mirror unit equipped with. The mirror unit according to claim 1, wherein the resin mirror has a thickness of 0.2 mm to 5.0 mm. 3. The mirror unit according to claim 1, wherein a thickness of the resin support of the resin mirror is 90% to 99% with respect to a thickness of the resin mirror. The mirror unit according to any one of claims 1 to 3, wherein the resin mirror is flexible. The mirror unit according to any one of claims 1 to 4, further comprising a reinforcing member that is provided on the resin support side of the frame and is connected to an opposing second base material. The mirror unit according to claim 5, wherein the reinforcing member is a plate that closes an opening of the frame. 5. The method according to claim 1, further comprising a reinforcing member that is provided on the resin support side of the frame body, is connected to an elongated first base material, and is parallel to the opposing second base material. The mirror unit according to item 1. The mirror unit according to any one of claims 5 to 7, further comprising a heat insulating layer between the reinforcing member and the resin mirror. The mirror unit according to any one of claims 1 to 8, further comprising a heat insulating layer on a surface of the holding groove that contacts the resin mirror. The mirror unit according to any one of claims 1 to 9, further comprising a resin mirror fixing member on a side of the frame body on which the resin mirror is inserted. The frame according to any one of claims 1 to 10, wherein the frame is curved so that the resin support side is convex, and the resin mirror is held so that the resin support side is convex. Mirror unit. 12. The mirror unit according to claim 1, which is used for collecting sunlight. A solar light reflector comprising: the mirror unit according to any one of claims 1 to 12; and a solar light tracking system that tracks the mirror unit in a solar diurnal motion.

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