JPS6324678A - Solar battery and electrical product using solar battery - Google Patents

Abstract

PURPOSE:To provide a solar battery with decorative and designing effect by means of forming a pattern layer on the photodetective surface of solar battery. CONSTITUTION:A pattern layer 4 is formed on a photodetecting surface 3 of a solar battery 2; cells 6 are connected by leads 5; the peripheral parts are coated with resin 7; glass plates 8, 9 forming upper and lower glass surfaces are fixed by frames 10. The pattern layer 4 is formed of a transparent hologram, a printed or transferred layer by transparent ink. The transparent hologram using embossed hologram is composed of a hologram effective layer 12 and a hologram layer 13 laminated on a solar battery through the intermediary of an adhesive 11. A resin hardened by ultraviolet rays or electron beams such as methyl (meth acrylate is optimum for the resin for embossed hologram. The layer 12 comprises Sb2S3, etc., or LiF, etc., or nylon, etc. no exceeding in thickness 200Angstrom refractive index different from that of hologram layer 13 to show the hologram effect. In such a constitution, a nice-looking solar battery in excellent decorative property can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to solar cells and electrical products using solar cells.

[Problems to be solved by conventional technology and invention]

Solar cells, which capture light and generate electricity through charging and conversion, are widely used in calculators, radios, televisions, watches, tape recorders, etc.

These conventional solar cells have a surface appearance of a single color such as black or green, and when such solar cells are incorporated into a product, there is a problem in that the beauty and decoration of the product are impaired. In other words, since the solar cells occupy a large proportion of the surface area of products incorporating such solar cells, the solar cells become a dead space in the product design, causing the product's aesthetic appearance to deteriorate. It became.

The present invention was made in view of the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a highly decorative solar cell and an electrical product using the solar cell.

[Means for solving problems]

The present inventors have arrived at the present invention as a result of research aimed at imparting even more superior mineral concentration and design effects to the conventional solar cells as described above.

That is, one of the gist of the present invention is a solar cell characterized by providing a pattern layer on the light-receiving surface of the cell.

Another aspect of the present invention is characterized in that it consists of an electrical product main body and a solar cell provided on the main body, and a pattern layer is provided on the light-receiving surface or above the light-receiving surface of the solar cell. The focus is on electrical products that use solar cells.

〔Example〕

Hereinafter, the present invention will be explained in detail based on specific examples shown in the drawings.

As the solar cell used in the present invention, any conventionally known solar cell can be used, for example, in terms of cell structure, pn junction type, MINP type, BSF type, or
It may have any structure such as a pin type in an amorphous St solar cell, and can also be used in a module form such as a super straight type module, a resin filled type module, a consumer solar cell module, etc.

The solar cell 1 of the present invention shown as an example in FIG.
It has been established.

The solar cell 2 has cells 6. connected by lead wires 5,5.
6 is covered with a resin [7], glass plates 8 and 9 are provided on the upper and lower surfaces, and these are fixed by a frame member 10. Note that 20 in the figure indicates a protective layer that protects the pattern layer.

The pattern layer in the present invention is provided on the light-receiving surface of the solar cell, but since the solar cell itself is opaque, if the pattern layer is provided on the surface opposite to the light-receiving surface of the solar cell, it cannot be observed from the top surface. It is for this purpose.

The pattern layer is preferably formed of a material with extremely good light transmittance, such as a transparent hologram, a pattern layer printed with transparent ink, or a transfer layer, but it can also be formed of a general opaque ink. When using non-transparent ink, it is preferable that the pictures, figures, letters, patterns, etc. that form the picture layer be drawn with lines, and if the thick lines or vector parts are covered, the light transmittance of the solar cell light-receiving surface will be reduced. It gets worse, and the electromotive force gets worse.

When using a transparent hologram as the pattern layer 4, for example, an embossed hologram is used as the transparent hologram as shown in the cross-sectional view in FIG. 2, and adhesive N is applied onto the solar cell.
1) can be used in which a hologram effect layer 12 and a hologram [13] are laminated via a layer.

Further, a structure in which a hologram effect layer is laminated on the surface of the hologram layer having minute irregularities, or a structure in which a hologram layer is provided on the surface of the hologram effect layer can also be used.

Moreover, the hologram effect layer 12 or the hologram forming layer 13
A protective layer can be provided thereon to protect the above layer. Such a protective layer is made of, for example, cellulose resin, acrylic resin, melamine resin, polyester resin, vinyl chloride resin, vinyl acetate resin! Using M resin, polycarbonate resin, silicone resin, fan resin, polyethylene resin, polypropylene resin, and polyamide resin alone, mixture, and copolymer, the above layer is coated with a thickness of about 0.1 to 10 μm by general printing means or coating means. Established in The thickness of the hologram layer 13 can be appropriately selected depending on the size of the solar cell and the type of hologram, but it is usually 0.1 to 50 μm, preferably 0.5 to 5 μm.

An embossed hologram is suitable for the present invention, and the resin for this embossed hologram is used to form (replicate) the hologram.
Sometimes it is thermoformable, and after the hologram is formed or processed, it needs to be resistant enough to withstand the heat pressure of processing and the solvents in the adhesive. As such a resin, reactive resins such as so-called ultraviolet curable resins, electron beam curable resins, thermosetting resins, and natural curable resins can be used. Especially when considering productivity, resins that are cured by ultraviolet rays or electron beams are suitable.

Specifically, for example, methyl (mec) acrylate [the term (mec) acrylate is meant to include both acrylate and methacrylate. Same below], ethyl (meth)acrylate, propyl (meth)
Acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isoamyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate
Acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hexadiol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tetra(meth)acrylate Acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, polyethylene glycol di(meth)acrylate, brobylene glycol diglycidyl ether di(meth)acrylate, Polypropylene glycol diglycidyl ether di(
Monomers having radically polymerizable unsaturated groups such as meth)acrylate and sorbitol tetraglycidyl ether tetra(meth)acrylate can be used.

Further, as an ultraviolet or electron beam curable resin having thermoformability, a polymer obtained by polymerizing or copolymerizing the following compounds +1) to (8) is subjected to radical polymerization by methods (a) to (d) described below. Those into which a sexually unsaturated group is introduced are used.

(1) Monomers with hydroxyl groups: N-methylol (meth)acrylamide, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3 -Phenoxyprobil (meth)acrylate, etc.

(2) Monomers having carboxyl groups: (meth)acrylic acid, (meth)acryloyloxyethyl monosuccinate, etc.

(3) Monomeric nigericidyl (meth)acrylate etc. having an epoxy group.

(4) Monomers having an aziridinyl group: 2-aziridinylethyl (meth)acrylate, allyl 2-aziridinylpropionate, etc.

(5) Monomers having amino groups: (meth)acrylamide, diaseptone (meth)acrylamide, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, etc.

(6) Monomer having a sulfone group: 2-(meth)
Acrylamido-2-methylpropanesulfonic acid, etc.

(7) Monomer having an isocyanate group: addition of a radical polymerizable monomer having a diisocyanate and active hydrogen, such as a 1 mol to 1 mol adduct of 2.4-toluene diisocyanate and 2-hydroxyethyl (meth)acrylate things etc.

(8) Furthermore, in order to adjust the glass transition point of the above copolymer and the physical properties of the cured film, the above compound and the following monomers that can be copolymerized with this compound are added. can be copolymerized.

Examples of such copolymerizable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, and t-butyl (meth)acrylate. ) acrylate, isoamyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and the like.

Next, the polymer obtained as described above is reacted by methods (a) to (d) described below to introduce a radically polymerizable unsaturated group, thereby obtaining an ultraviolet or electron beam curable resin. .

(a) In the case of a +II polymer or copolymer having a hydroxyl group, a monomer having a carboxyl group such as (meth)acrylic acid is subjected to a condensation reaction.

(b) In the case of a polymer or copolymer of monomers having a carboxyl group or a sulfone group, the aforementioned monomers having a hydroxyl group are subjected to a condensation reaction.

(c) In the case of a polymer or copolymer of a monomer having an epoxy group, an isocyanate group, or an aziridinyl group, the above-mentioned monomer having a hydroxyl group or monomer having a carboxyl group is subjected to an addition reaction.

(d) In the case of a polymer or copolymer of a monomer having a hydroxyl group or a carboxyl group, a monomer having an epoxy group or a monomer having an aziridinyl group or a diisocyanate compound and a hydroxyl group-containing acrylic acid ester monomer The addition reaction may be carried out using a 1:1 molar ratio of adducts.

Furthermore, the above-mentioned monomer and the above-mentioned thermoformable ultraviolet ray or electron beam curable resin can be mixed and used.

In addition, the above substances can be sufficiently cured by electron beam irradiation, but when curing by ultraviolet irradiation, as a sensitizer,
It is also possible to use benzoin ethers such as benzoquinone, benzoin, and benzoin methyl ether, and halogenated acetophenones that generate radicals when irradiated with ultraviolet rays.

The hologram effect layer 12 is capable of producing a hologram effect, and includes, for example, a transparent material having a different refractive index from that of the hologram N13, a metal thin film layer having a thickness of less than 200 mm, and the like. In the former case, the refractive index may be larger or smaller than that of the hologram layer 13, but the difference in refractive index is preferably 0.1 or more, more preferably 0.5 or more, but preferably 1.0 or more. Optimal. In the case of the latter, although it is a fully refractive thin film, the thickness is less than 200 mm, so the transmittance of light waves is high, and therefore, in addition to the effect of producing a hologram effect, it also exhibits the effect of not obscuring the lower part, for example, the display section. Examples of the material for the hologram effect layer include the following.

il+ A transparent continuous thin film with a higher refractive index than the hologram layer.

There are two types of these: those that are transparent in the visible region and those that are transparent in the infrared or ultraviolet region; an example of the former is 5biS3 (
3,0), FezOz(2,7), Pb0(2,6),
Zn5e(2,6).

Cd5(2,6), Bix0*(2,4), Ti0z(
2,3), Pbc l g(2,3).

Cent (2,2) +TazOs (2,2),
Zn5(2,1), ZnO(2,1), Cd0(
2゜1) , NdtOs (2,1) 1SbzOi
(2,0) , Zr0t (2,0) , WOs
(2,0).

PrhO+ 1 (2,0), 5iO(2,0)
, IntOx (2,0), Y2O3(1,9),
Tio(1,9), Th0z(1,9), 5itOz
(1,9), PbFz(1,8)lCd 0°(1,8
), LatOs(1,8), Mg0(1,7), A
l zoz (1,6), LaFs (1,6), CaO・
5iOz(1,6), CeF3(1,6), NdF*(
1,6), SiO□(1,5), 5iOi(1,5),
Examples of the latter include Cd5e(3,5), CdTe(2,6), Ge(4,
(1-4.4), Hf0t(2,2), PbTe(5,
6), 5i(3,4), Te(4,9), Tj!
Examples include C1(2,6), ZnTe(2,8), and the like.

Note that the value in parentheses above indicates the refractive index. (Hereinafter, (2) to (
The same applies to 5)) (2) A transparent ferroelectric material with a higher refractive index than the hologram layer.

For example, CuC1(2,0), CuBr(2,2),
GaAs (3,3-3.6).

GaP(3,3~3.6), Na(CHz) 6(1
,6), old r(GeO4) 3 (2,1).

Kll! PO4 (KDP) (1,5), DZPO4
(1,5) ,NH,,H1PO4,(1,5).

KII*As0a(1,6)lRb■i^sot (1
,6) + KTao, hsNbo, zso* (2゜3
) + Ko-6Ll 1). 4Nboi (2-3)
+ KSrzNbsO+ s (2-3) + 5r
xBat-X NbxOa (2,3) + BaJa
NbO+ s (2,3) + LiNb0z (2,
3) +LiTa0. (2,2), BaTiOs
(2,4), 5rTiOz (2,4), K
Examples include TaOz (2°2).

(3) Transparent continuous FJ III with a lower refractive index than the hologram layer.

For example, LiF(1,4), MgFz(1,4), 3Na
F ・ ^1Fi(1,4), ^I Fi(1,4
), GaFz(1,3), NaF(1,3), etc.

(4) Reflective metal thin film with a thickness of 200 Å or less.

The reflective metal thin film has a complex refractive index, and the complex refractive index: n
A book is represented by H*=n−iK. n is the refractive index, and K is the absorption coefficient. The materials of the reflective metal thin film used in the present invention are shown below, and the values of n and K are shown at the same time.

B e (n=2.7, K=0.9), Mg
(n = 0.6.

K=6.1), Ca (n=0.3, K=
8.1), S r (n=0.6, K=3.
2), Ba (n=0.9, K=1.7)
.

La (n=1.8, K=1.9), Ce
(n=1.7, K=1.4), Cr (n
-3,3, K=1.3), Mn (n=2.5,
K=1.3), Cu (n-0,7, K=2.
4), Ag (n=0.1, K=3.3),
Au (n=0.3, K=2.4), Aj!
(n=0.8, K-5,3), Sb (n
=3゜0, K=1.6), Pd (n-1
,9, K=1.3), N i(n -1,8, K=1
．． 8), etc.

Other materials include Sn, In, Te, and Ti.

Fe, Co, Zn, Ge, Pb, Cd, Bi, Se, G
a, Rb, etc. can be used. In addition, oxides, nitrides, etc. of the metals listed above can also be used, and metals, their oxides, nitrides, etc. can be used alone or in combination with each other.
More than one species can be used in combination.

(5) A resin having a different refractive index from the hologram layer may have a large or small refractive index for the hologram layer. For example, polytetrafluoroethylene (1,5),
Polychlorotrifluoroethylene (1,43), vinyl acetate resin (1,45-1.47), polyethylene (1
, 50-1.54), polypropylene (l, 49),
Methyl methacrylate resin (1,49), nylon (1
, 53), polystyrene (1,60), polyvinylidene chloride (1,60-1,63), vinyl butyral resin (1,48), vinyl formal resin (1,50), polyvinyl chloride (1,52- 1.55), polyester resin (1,52-1.57), carbonic acid formalin resin (
1.5 to 1.7), and in addition to the above, general synthetic resins can be used.

In particular, a resin having a large refractive index difference with that of the hologram layer is preferable.

(6) A laminate formed by appropriately combining the materials listed in (1) to (5) above.

The above materials (1) to (5) may be combined arbitrarily, and the vertical positional relationship of each layer in the layer structure may also be arbitrarily selected.

Among the hologram effect layers (1) to (6) described above, (
The thickness of the hologram effect layer in 4) is less than 200 layers, but the thickness of the hologram effect layers in (1) to (3), (5), and (6) may be in the transparent region of the material forming the thin film. Generally, the number is preferably 10 to 10,000 people, more preferably 100 to 5,000 people.

Above hologram effect! 12 in the hologram layer 13, the hologram effect layer 13 can be formed using the above (1) to (
If the material is 4), general thin film forming methods such as vacuum evaporation, sputtering, reactive sputtering, ion blating, or electroplating can be used. In some cases, general coating methods etc. can be used. Moreover, when the material is the one mentioned in (6) above, the above-mentioned means, methods, etc. can be used in combination as appropriate.

The adhesive FJII serves to adhere the hologram FJ13 and the hologram effect layer 12 to the light-receiving surface of the solar cell.

As the adhesive, a wide variety of conventional adhesives such as acrylic resins, vinyl resins, polyester resins, urethane resins, amide resins, and epoxy resins can be used. The film thickness of this adhesive layer is preferably 0.1 to 50 μm, preferably 0.5 to 10 μm.

Note that an anchor layer may be provided between the hologram effect layer 12 and the adhesive Ji51) in order to improve the adhesiveness between the two.

The transparent hologram can be formed on the light-receiving surface not only by adhesion using the adhesive layer described above but also by transfer using a transparent hologram transfer sheet.

The protection fli@20 is provided for the purpose of protecting the pattern layer, and may or may not be present, and can be appropriately selected and used.

The material of the protective layer 20 includes glass; acrylic, polycarbonate, FRP, polyethylene, polypropylene,
Sheets or films made of vinyl chloride, polyamide, polyester, etc., as well as cellulose resins, acrylic resins, melamine resins, polyester resins, vinyl chloride resins, vinyl acetate resins, polycarbonate resins, silicone resins, fan resins, Examples include those obtained by applying simple substances, mixtures, and copolymers of polyethylene resin, polypropylene resin, and polyamide resin by general printing means and coating means.

For batteries that use a transparent hologram as the pattern layer, a three-dimensional pattern can be observed on the battery surface, and although transparent holograms have a large amount of light reflection at the angle at which the hologram is viewed, they have sufficient light transmission at other angles. Therefore, the loss of light amount is extremely small and there is no problem of poor electromotive force.

Further, in the solar cell of the present invention, the pattern layer can be formed using transparent ink.

In this case, light can be received by applying transparent ink to the light-receiving surface of the solar cell using a conventionally known printing method, or by transferring a pattern to the light-receiving surface using a transfer sheet with a pattern formed with transparent ink. A pattern layer can be formed on the surface.

As the printing method, known printing methods such as silk screen printing, gravure printing, and gravure offset printing can be used.

Further, as the transparent ink, an ink using alumina white, calcium carbonate, magnesium carbonate, barium sulfate, etc. as a pigment, or an ink using a dye can be used. Furthermore, even if an ink that is colored to be transparent to some extent is used, the transparency will be reduced, but if the image is printed with a small area covered, it is possible to suppress the power generation capacity of the solar cell to below the necessary level.

Further, in the present invention, the pattern layer can be formed using ordinary opaque ink. When using an opaque ink, the pattern layer can be formed by the same printing method and transfer method as in the case of using the above-mentioned transparent ink, but it is preferable that the content of the pattern is drawn with lines.

FIG. 3 and FIG. 4 show an example of an electric product using a solar cell according to the present invention, and show the electric power <Li2 using the solar cell. The calculator 14 has a calculator main body 15
and a thick IKj5 battery 16 provided on the main body 15, and the solar cell 16 is formed by sequentially laminating a pattern N19 and a protective IJ20 on the light receiving surface 18 of the battery main body 17. In the figure, 21 is a glass plate provided on the calculator main body 15, but this may not be the case depending on the material and shape of the protective layer 20.

For the solar cell 16 and the pattern layer 19, the same ones as those described in the explanation of the solar cell can be used.

Further, in FIG. 4, the pattern layer 18 is provided integrally with the solar cell 16, but is not limited to this.
As shown in the figure, it is also possible to provide a separate pattern N19 above the light-receiving surface 18 of the solar cell 16.

In addition to the above-mentioned calculator, the electrical appliances to which the present invention can be applied include all appliances that can use solar cells, such as batteries, clocks, radios, tape recorders, televisions, and the like.

The electrical product of the present invention has a pattern layer on the light-receiving surface of the solar cell or the upper part of the light-receiving surface of the thick R'1 pond, so it is extremely decorative and improves the product value.

〔Effect of the invention〕

As explained above, since the solar cell of the present invention and the electrical products using the solar cell are provided with a pattern layer, they are extremely decorative compared to conventional ones, and the beauty of the product is further improved. It is effective.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view showing a solar cell with a pattern showing one embodiment of the invention, FIG. 2 is a longitudinal sectional view showing an example of a transparent hologram, and FIG. 3 is a longitudinal sectional view showing an example of a transparent hologram. 1 is a perspective view showing a calculator which is an example of an electrical product using the solar cell of the present invention, FIG. 4 is a schematic vertical cross-sectional view taken along the line rV-4 in FIG. 3, and FIG. FIG. 2 is a schematic vertical cross-sectional view of main parts showing an embodiment of the present invention.゛ 1...Solar cell 3.18...Light receiving surface 4.19...Picture layer 14...Calculator using solar cells Figure 1 Figure 3 7y'''-7 Figure 4 Noah

Claims (6)

[Claims] (1) A solar cell with a pattern, characterized in that a pattern layer is provided on the light-receiving surface of the battery. (2) The solar cell according to claim 1, wherein the pattern layer is a transparent hologram. (3) The solar cell according to claim 1, wherein the pattern layer is formed of transparent ink. (4) A solar cell comprising a main body of an electrical appliance and a solar cell provided in the main body, and a pattern layer is provided on the light-receiving surface of the solar cell or the upper part of the light-receiving surface of the solar cell. Electric appliances. (5) The electrical product according to claim 4, wherein the pattern layer is a transparent hologram. (6) The electrical product according to claim 4, wherein the pattern layer is formed of transparent ink.