KR20110048474A - Adhesive sheet for protecting solar cell module back surface and solar cell module using same - Google Patents

Abstract

PURPOSE: An adhesive sheet for protecting back sheet for a photovoltaic module and the photovoltaic module using the same are provided to extend the lifespan of a solar cell module by preventing the deterioration of a charge layer and a solar cell module due to vapor inflow. CONSTITUTION: In an adhesive sheet for protecting back sheet for a photovoltaic module and the photovoltaic module using the same, a base layer(2) is made of a synthetic resin. An adhesive layer(3) is laminated in one side of the base layer. The average thickness of the base layer is 0.01mm-1mm. A barrier layer(4) is laminated in the other side of base layer. The base layer is formed by depositing inorganic oxide in one side of the base layer.

Description

Adhesion sheet for solar cell backside protection and solar cell module using same {ADHESIVE SHEET FOR PROTECTING BACK SHEET FOR PHOTOVOLTAIC MODULE AND PHOTOVOLTAIC MODULE USING THE SAME}

The present invention relates to an adhesive sheet for protecting the back surface of a solar cell module and a solar cell module using the same.

In recent years, with the increasing awareness of environmental problems such as global warming, photovoltaic power generation as a clean energy source has been attracting attention, and solar cells formed from various forms have been developed. This solar cell is generally composed of a plurality of solar cell modules packaged in units of a plurality of solar cell cells wired in series or in parallel.

The solar cell module is required to have sufficient durability, weather resistance and the like that can be used for a long time outdoors. As shown in FIG. 7, as a specific structure of the general solar cell module 61, the light-transmissive substrate 62 which consists of glass etc., the filler layer 63 which consists of thermoplastic resins, such as ethylene vinyl acetate copolymer (EVA), A plurality of solar cells 64 as photovoltaic elements, a filler layer 65 similar to the filler layer 63, and a back sheet 66 for a solar cell module are laminated in this order from the surface side, It is integrally formed by vacuum heating lamination method. In addition, each solar cell 64 is wired in series or in parallel, and both terminals 67 of this wiring are externally wired through a junction box 68 provided on the rear surface (back sheet 66) side. Is connected to the terminal.

In the solar cell module, when water vapor, oxygen gas, or the like penetrates inside, there is a concern that peeling and discoloration of the filler layers 63 and 65, corrosion of wiring, deterioration of the solar cell 64, and the like are caused. For this reason, the solar cell module back sheet 66 is required to have basic performances such as strength, weather resistance and heat resistance, as well as gas barrier properties against water vapor, oxygen gas and the like. As the conventional solar cell module back sheet 66, for example, a multilayer structure in which a pair of synthetic resin layers are laminated on both surfaces of a gas barrier layer is employed. As a specific conventional solar cell module back sheet 66, (a) a structure in which a pair of polyvinyl fluoride films are laminated on both sides of an aluminum foil (see Japanese Patent Laid-Open No. 6-177412, etc.), or (b ) And a structure in which a polyethylene terephthalate film is laminated on both surfaces of a resin film on which metal oxide is deposited (see Japanese Patent Application Laid-Open No. 2002-100788, etc.).

However, in the conventional solar cell module back sheet 66 and the solar cell module 61 including the same, it is difficult to prevent the occurrence of scratches from physical shocks occurring when the solar cell panel is installed. Physical defects 69 such as scratches generated from such physical shocks or cracks caused by long-term use lower the durability, insulation, water vapor barrier property, etc. of the back sheet 66, and further, the filler layers 63, 65 Causes deterioration of the photovoltaic cell, which results in deterioration of the function of the solar cell 64 itself. Accordingly, although the main body of the solar cell 64 and the like can still be used sufficiently, if a physical defect such as a crack occurs in the back sheet 66, there is a problem that long-term use of the solar cell module itself cannot be performed. exist.

Japanese Patent Application Laid-Open No. 6-177412 Japanese Patent Application Laid-Open No. 2002-100788

(Summary of invention)

(Tasks to be solved by the invention)

SUMMARY OF THE INVENTION The present invention has been made in view of these problems and suppresses the progress of physical defects such as scratches and cracks generated in the back sheet due to physical shock or long-term use to the solar cell module, and also allows water vapor to enter from the physical defect portion. It is an object of the present invention to provide a pressure-sensitive adhesive sheet for protecting the back surface of a solar cell module and a solar cell module using the same to prevent deterioration of a charge layer and a solar cell which may occur due to the solar cell module.

The invention made in order to solve the said subject,

It is provided with the base material layer made of synthetic resins, and the adhesive layer laminated | stacked on one surface side of this base material layer,

It is an adhesive sheet for solar cell module back surface protections whose average thickness of this adhesive layer is 0.01 mm or more and 1 mm or less.

According to the pressure-sensitive adhesive sheet for protecting the back surface of the solar cell module, the pressure-sensitive adhesive sheet is laminated on the back surface of the back sheet on the back surface of the solar cell module where physical defects such as scratches and cracks are generated, thereby preventing entry of water vapor or the like from the physical defect portion. In addition, expansion of a defective part can be suppressed. Moreover, according to the said adhesive sheet for solar cell module back surface protection, since the average thickness of an adhesive layer is 0.01 mm or more and 1 mm or less, a flaw and a flaw are filled by filling the adhesive layer to the highest depth part of the physical defect part which may normally occur in a back sheet. It is possible to reliably prevent expansion of defects such as cracks and intrusion into the solar cell module from the outside such as water vapor. That is, according to the said adhesive sheet for solar cell module back surface protection, long life of a solar cell module can be realized by sticking to the back sheet back surface by the adhesive layer.

It is preferable that an acrylic adhesive is used as an adhesive which comprises the said adhesive layer. According to the pressure-sensitive adhesive sheet for protecting the solar cell module back surface, by using an acrylic pressure-sensitive adhesive having excellent adhesive strength and excellent durability and weather resistance, it is possible to reliably increase the suppression of physical defect expansion and the intrusion prevention function such as water vapor, and the function thereof. Can last a long time.

A butyl rubber type adhesive may be used as an adhesive which comprises the said adhesive layer. According to the pressure-sensitive adhesive sheet for protecting the back of the solar cell module, since a butyl rubber-based pressure-sensitive adhesive having good weather resistance, cold resistance, and unevenness can be used as an adhesive, it is possible to reliably increase the suppression of physical defect expansion and the intrusion prevention function such as water vapor. Long lasting function.

It is preferable that an ultraviolet curable adhesive is used as an adhesive which comprises the said adhesive layer. According to the said adhesive sheet for solar cell module back surface protection, since an ultraviolet curable adhesive is used as an adhesive agent, after sticking this adhesive sheet to the back surface of a solar cell module, it will be ultraviolet-cured gradually by exposure to sunlight. For this reason, according to the said adhesive sheet for solar cell module back surface protection, the clearance gap of a physical defect can be reliably filled, the expansion can be prevented, and the intensity | strength of this adhesive sheet can be raised.

The barrier layer laminated | stacked on the other surface side of the said base material layer, and / or between the said base material layer and an adhesive layer, and this barrier layer should just contain the inorganic substance. As described above, the pressure-sensitive adhesive sheet for protecting the back surface of the solar cell module includes a barrier layer containing an inorganic substance, and has a higher gas barrier property such as water vapor, and can improve mechanical strength.

The inorganic substance may be an inorganic oxide or aluminum. According to the adhesive sheet for protecting the back of the solar cell module, by including the inorganic oxide or aluminum in the barrier layer, the gas barrier property and mechanical strength are further increased, and the temperature rise of the solar cell is suppressed by the heat dissipation effect. Longer life of the module can be further promoted. Moreover, according to the said adhesive sheet for solar cell module back surface protection, since it has a layer containing a metal in this way, rigidity becomes high and the sheet handling property and workability at the time of sheet installation etc. improve.

It is preferable that the said barrier layer is laminated | stacked in multiple layers. In the adhesive sheet for solar cell module back surface protection, since a barrier layer is laminated | stacked, the gas barrier property and mechanical strength can be improved significantly.

One surface of the said adhesive layer should just be coat | covered with a release sheet. Since the adhesive sheet for solar cell module back surface protection is coat | covered with one surface with a release sheet, since an adhesive layer can be prevented from contacting another thing until just before sticking work, workability is high and at the time of sticking The adhesive function of the adhesive sheet of can be improved.

Therefore, it is a solar cell module in which a transparent substrate, a filler layer, a solar cell as a photovoltaic element, a filler layer, a back sheet, and the said adhesive sheet for back surface protection of the said solar cell module are laminated | stacked in this order from the surface side, According to the solar cell module, the adhesive sheet for protecting the back surface of the solar cell module is attached to the back surface of the back sheet by the adhesive layer, even when a physical defect such as a scratch or crack occurs on the back surface of the back sheet. Since the adhesive sheet for back surface protection of a battery module can suppress expansion of a physical defect and can permeate | transmit water vapor from this physical defect part, it can promote long life of a solar cell module. Moreover, according to the said solar cell module, generation | occurrence | production of the physical defect on the back surface back surface itself can be suppressed.

Here, the "surface side" of the solar cell module means the light receiving surface side of the solar cell module. "Back side" means the surface side, ie, the surface opposite to the said light-receiving surface side.

As explained above, according to the adhesive sheet for solar cell module back surface protection of this invention, when a physical defect, such as a flaw and a crack, generate | occur | produces on the back sheet back surface of a solar cell module, it adhere | attaches this adhesive sheet with this adhesive layer. The pressure-sensitive adhesive layer fills in the defective portion, suppresses the expansion of the defective portion, and prevents entry of water vapor and the like from the defective portion, thereby preventing deterioration of the solar cell module and achieving longer life. Therefore, the solar cell module provided with the adhesive sheet for solar cell module back surface protection of this invention can suppress deterioration of a charge layer and a solar cell, and can use for a long term.

BRIEF DESCRIPTION OF THE DRAWINGS It is typical sectional drawing which shows the adhesive sheet for solar cell module back surface protection which concerns on one Embodiment of this invention.
FIG. 2 is a schematic cross-sectional view showing a solar cell module back protective adhesive sheet according to a different form from the solar cell module back protective adhesive sheet of FIG. 1;
3 is a schematic cross-sectional view showing a solar cell module back protective adhesive sheet according to a different form from the solar cell module back protective adhesive sheet of FIGS. 1 and 2;
4 is a schematic cross-sectional view showing a solar cell module back protective adhesive sheet according to a different form from the solar cell module back protective adhesive sheet of FIGS. 1, 2 and 3;
5 is a schematic cross-sectional view showing a solar cell module back surface protective adhesive sheet according to a different form from the solar cell module back surface protective adhesive sheet of FIGS. 1 to 4;
6 is a schematic cross-sectional view showing a solar cell module using the adhesive sheet for protecting the solar cell module back surface of Figure 1,
7 is a schematic cross-sectional view showing a conventional general solar cell module.

(Form to carry out invention)

EMBODIMENT OF THE INVENTION Hereinafter, the adhesive sheet for solar cell module back surface protection of this invention, and the solar cell module using the same are demonstrated in detail, referring drawings suitably.

The adhesive sheet 1 for back surface protection of the solar cell module of FIG. 1 is equipped with the base material layer 2 and the adhesive layer 3 laminated | stacked on one surface side of this base material layer 2.

The base material layer 2 is formed using synthetic resin as a main component. It does not specifically limit as synthetic resin of the main component of this base material layer 2, For example, polyolefin resin, a fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polyamide type Resin, polyimide resin, polyamideimide resin, polyaryl phthalate resin, silicone resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, polyurethane resin, acetal resin, cellulose Resins, acrylonitrile-styrene copolymers (AS resins), acrylonitrile-butadiene-styrene copolymers (ABS resins), polyvinyl chloride resins, and the like. Among the above resins, polyolefin-based resins, polyester-based resins and fluorine-based resins having high heat resistance, physical strength, weather resistance, durability, gas barrier properties against water vapor, and the like are preferable.

As said polyolefin resin, polyethylene (for example, high density polyethylene, low density polyethylene, etc.), polypropylene, copolymer of ethylene and unsaturated carboxylic acid ester (for example, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate in air) Copolymer, ethylene-methyl methacrylate copolymer, etc.), copolymer of ethylene and unsaturated carboxylic acid (for example, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, etc.), ionomer resin, etc. are mentioned. . Among these, polyethylene having a good balance of various functional and cost aspects such as hydrolysis resistance, heat resistance, weather resistance, and the like, and cyclic polyolefin resins excellent in functionality such as heat resistance, strength, weather resistance, durability, and gas barrier properties are preferable.

As said cyclic polyolefin type resin, it is a) cyclopentadiene (and its derivative), dicyclopentadiene (and its derivative), cyclohexadiene (and its derivative), norbornadiene (and its derivative), for example. Polymers formed by polymerizing cyclic dienes such as b) Cos formed by copolymerizing one or two or more olefinic monomers such as cyclic diene and ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene and isoprene. Polymers; Among these cyclic polyolefin resins, polymers of cyclic dienes such as cyclopentadiene (and its derivatives), dicyclopentadiene (and its derivatives) or norbornadiene (and its derivatives) having excellent strength, heat resistance and weather resistance, Particularly preferred.

As said polyester-based resin, polyethylene terephthalate, polyethylene naphthalate, etc. are mentioned, for example. Among these polyester resins, polyethylene terephthalate having a good balance of various functional aspects such as heat resistance and weather resistance and price is particularly preferable.

As said fluorine-type resin, For example, perfluoroalkoxy resin (PFA) which consists of polytetrafluoroethylene (PTFE), copolymer of tetrafluoroethylene, and a perfluoroalkyl vinyl ether, tetrafluoroethylene, and hexa Copolymer of fluoropropylene (FEP), Copolymer of tetrafluoroethylene with perfluoroalkyl vinyl ether and hexafluoropropylene (EPE), Copolymer of tetrafluoroethylene with ethylene or propylene (ETFE) And polychlorotrifluoroethylene resin (PCTFE), copolymers of ethylene and chlorotrifluoroethylene (ECTFE), vinylidene fluoride resin (PVDF), and vinyl fluoride resin (PVF). Among these fluorine resins, polyvinyl fluoride resins (PVF) having excellent strength, heat resistance, weather resistance, and the like, and copolymers of tetrafluoroethylene with ethylene or propylene (ETFE) are particularly preferable.

In addition, as a formation material of the base material layer 2, the said synthetic resin can be used 1 type or in mixture of 2 or more types. Moreover, in the forming material of the base material layer 2, various additives etc. can be mixed in order to improve and modify workability, heat resistance, weather resistance, mechanical properties, dimensional stability, etc. Examples of the additives include lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing fibers, reinforcing agents, antistatic agents, flame retardants, flame retardants, foaming agents, mold inhibitors, and pigments. It does not specifically limit as a shaping | molding method of the said base material layer 2, For example, well-known methods, such as an extrusion method, the cast molding method, the T-die method, the cutting method, the inflation method, are employ | adopted. The base material layer 2 may have a single layer structure or a multilayer structure of two or more layers.

As a minimum of the average thickness of the base material layer 2, 0.3 mm is preferable and 0.5 mm is especially preferable. On the other hand, as an upper limit of the average thickness of the base material layer 2, 5 mm is preferable and 3 mm is especially preferable.

If the average thickness of the base material layer 2 is less than the said lower limit, handling of the said adhesive sheet 1 for solar cell module back surface protection will become difficult, and the problem that functionalities, such as a barrier property of water vapor, will become inadequate arises. In particular, since the adhesive sheet for protecting the solar cell module back surface is cut in accordance with the size of the existing solar cell module and the position and size of the junction box of the solar cell module, it is bonded to the back surface of the solar cell module, so that the average thickness is If it is less than the lower limit, the workability at the time of cut and paste is reduced, and the bonding corresponding to each solar cell module size becomes difficult, or the bonding with the back sheet is lowered by bonding together, and the defect expansion prevention function, water vapor, etc. There is a possibility that the barrier function cannot be sufficiently exhibited.

On the contrary, if the average thickness of the base material layer 2 exceeds the said upper limit, it will be against the request of thickness reduction and weight reduction of a solar cell module. Moreover, when the average thickness of the base material layer 2 exceeds the said upper limit, since the weight of the adhesive sheet 1 for solar cell module back surface protection increases, the workability at the time of bonding to a back surface falls similarly, and each aspect Bonding corresponding to the battery module size becomes difficult, or when bonding off, the adhesiveness with the back sheet is lowered, and there is a possibility that the barrier expansion function such as defect expansion prevention function and water vapor cannot be sufficiently exhibited.

What is necessary is just to disperse | distribute a pigment in the base material layer 2. Thus, by disperse | distributing a pigment in the base material layer 2, various characteristics, such as heat resistance, weather resistance, durability, thermal dimensional stability, and intensity | strength of the base material layer 2 and also the said solar cell module back surface protective adhesive sheet 1, are improved. You can. Moreover, by disperse | distributing and containing a white pigment in the base material layer 2, the function which reflects the light ray which permeate | transmitted the solar cell is added, and power generation efficiency can be improved more. Moreover, the design of a solar cell module can be improved by disperse | distributing a black pigment etc. in the base material layer 2, and coloring the base material layer 2 in various colors.

It does not specifically limit as this white pigment, For example, calcium carbonate, titanium oxide, zinc oxide, lead carbonate, barium sulfate, etc. can be used. Especially, the calcium carbonate which is excellent in the dispersibility in the resin material which forms the base material layer 2, and relatively large in the improvement effect of durability, heat resistance, strength, etc. of the base material layer 2 is preferable. This calcium carbonate has crystal types such as calsite, aragonite, and batite, and any crystal type can be used. This calcium carbonate may be surface-treated with stearic acid, sodium dodecylbenzenesulfonate, a silane coupling agent, a titanium coupling agent, or the like, and may contain about 10% or less of impurities such as magnesium oxide, aluminum oxide, silicon dioxide, and titanium dioxide. do. As other pigments, black pigments, such as carbon black, blue pigments, such as ultramarine and blue blue, red pigments, such as red oxide (iron oxide), cadmium red, and molybdenum orange, metal powder pigments which give metallic luster, etc. are mentioned, It contributes to improving the design of the solar cell module.

As for the average particle diameter of the said pigment, 100 nm or more and 30 micrometers or less are preferable, and 300 nm or more and 3 micrometers or less are especially preferable. In addition, the average particle diameter in this invention means what averaged the particle diameter of 30 particle | grains extracted randomly from the particle | grains observed with the electron microscope of 1000 times magnification. The particle diameter is defined by the Feret diameter (the spacing when the projection image is sandwiched in parallel lines in a constant direction).

When the average particle diameter of a pigment is smaller than the said range, there exists a possibility that uniform dispersion | distribution to the base material layer 2 may become difficult by aggregation or the like. On the other hand, when the average particle diameter of a pigment exceeds the said range, there exists a possibility that various characteristic improvement effects, such as heat resistance with respect to the said base material layer 2, may fall.

As content of the said pigment, 8 mass% or more and 30 mass% or less are preferable. When content of a pigment is smaller than the said minimum, the improvement effect, such as durability, heat resistance, and strength of the base material layer 2, becomes small. On the other hand, when content of a pigment exceeds the said upper limit, there exists a possibility that the dispersibility of the pigment in the base material layer 2 may fall, and the fall of the intensity | strength of the base material layer 2 may be caused.

Moreover, what is necessary is just to perform a top-coat process to the other surface (surface of the side which contact | connects outside air) of the base material layer 2. As described above, the other side of the base material layer 2 is subjected to a top coat treatment to seal and protect the base material layer 2. As a result, the handleability of the adhesive sheet 1 is improved, and the base material layer 2 is further improved. Even if there is a flaw or a defect such as a recess, a decrease in strength or weather resistance is suppressed, and aging deterioration of the base material layer 2 is reduced.

As a topcoat agent used for the said topcoat process, a polyester topcoat agent, a polyamide topcoat agent, a polyurethane topcoat agent, an epoxy topcoat agent, a phenolic topcoat agent, (meth A polyolefin topcoat agent, such as an acrylic topcoat agent, a polyvinyl acetate type topcoat agent, polyethylene, or a polypropylene, a cellulose topcoat agent, etc. are mentioned. Among these topcoat agents, a polyester-based topcoat agent which has high adhesive strength with the base material layer 2 and contributes to surface protection of the base material layer 2 is especially preferable.

As a minimum of the coating amount (solid content conversion) of the said topcoat agent, 1 g / m <^2> is preferable and 3 g / m <^2> is especially preferable. On the other hand, as an upper limit of the coating amount of the said topcoat agent, 10 g / m <^2> is preferable and 7 g / m <^2> is especially preferable. When the coating amount of the top coat agent is smaller than the lower limit, there is a fear that the effect of protecting the base layer 2 is reduced. On the other hand, even if the coating amount of the top coat agent exceeds the upper limit, the protective effect of the base layer 2 does not increase so much, but rather the thickness of the pressure-sensitive adhesive sheet 1 increases, contrary to the request for thinning and weight reduction. There is concern.

Moreover, in the said top coat agent, various additives, such as a silane coupling agent for improving adhesiveness, an ultraviolet absorber for improving weather resistance, etc., an inorganic filler for improving heat resistance, etc. can be mixed suitably. As a mixed amount of such an additive, 0.1 mass% or more and 10 mass% or less are preferable for the balance between the effect expression of an additive, and the function impairment of a topcoat agent.

As a ultraviolet absorber contained in a topcoat agent, if it absorbs an ultraviolet-ray and can be converted into heat energy efficiently, and is a compound stable to light, a well-known thing can be used. Among them, the salicylic acid type ultraviolet absorber, the benzophenone type ultraviolet absorber, the benzotriazole type ultraviolet absorber, and the cyanoacrylate type ultraviolet absorber which have high ultraviolet absorption function, are compatible with the said top coat agent, and exist stably. It is preferable to use one or two or more selected from these groups. Moreover, as a ultraviolet absorber, the polymer (for example, "Ultra UV" series of Nippon Shokubai Co., Ltd.) which has an ultraviolet absorber in a molecular chain is used suitably. By using a polymer having an ultraviolet absorber in such a molecular chain, compatibility with the top coat agent is high, and deterioration of the ultraviolet absorbing function due to bleeding out of the ultraviolet absorbent can be prevented.

The adhesive layer 3 is formed by coating an adhesive on one surface of the base material layer 2. As a minimum of the average thickness of the adhesive layer 3, it is 0.01 mm, 0.015 mm is preferable and 0.02 mm is especially preferable. Moreover, as an upper limit of the average thickness of the adhesive layer 3, it becomes 1 mm, 0.1 mm is preferable and 0.05 mm is especially preferable. According to the said adhesive sheet 1 for back surface protection of the solar cell module in which the adhesive layer 3 has the said average thickness, the said adhesive sheet 1 is carried out on the back sheet surface of the back surface of the solar cell module in which a physical defect, such as a flaw and a crack, arose. By laminating, the ingress of water vapor from the physical defect portion can be prevented and the expansion of the physical defect can be suppressed. Moreover, according to the said adhesive sheet 1 for back surface protection of a solar cell module, since the average thickness of the adhesive layer 3 is the said range, the adhesive layer 3 can be filled to the highest depth part of the physical defect which normally arises. It is possible to reliably prevent the expansion of physical defects such as cracks, scratches and cracks, and to prevent intrusion from the outside such as water vapor.

If the average thickness of the adhesive layer 3 is less than the said lower limit, an adhesive cannot fill the depth of a physical defect, such as a normal flaw and a crack which arises normally, a gap will arise and an enlargement of a defect will advance easily, and from this gap As water vapor or the like enters, barrier properties such as water vapor decrease. On the contrary, when the average thickness of the adhesive layer 3 exceeds the said upper limit, workability may fall, for example, causing trouble when cutting the said adhesive sheet to a desired shape because of the thickness of the adhesive layer 3, for example. There is.

Although it does not specifically limit as an adhesive used for this adhesive layer 3, For example, Synthetic rubber adhesives, such as an acrylic adhesive, an acrylic- rubber type adhesive, a natural rubber type adhesive, a butyl rubber type, a silicone type adhesive, a polyurethane type adhesive, an epoxy type, Pressure-sensitive adhesives, polyethylene-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, and the like, and of these, acrylic pressure-sensitive adhesives, or weather resistance, weather resistance, and unevenness, because they have good adhesion, holding power, balance of tack, durability and weather resistance, and are available at low cost. It is especially preferable that it is a butyl rubber-type adhesive with a favorable track | trackability to.

Although it does not specifically limit as a monomer which comprises an acrylic adhesive, For example, methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, isobutyl acrylate, t-butyl acrylate, n-octyl acryl Acrylate, alkyl acrylates such as isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, ethyl methacrylate, n-butyl acrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, meta Alkyl acrylate (as alkyl group, for example, having 1 to 20 carbon atoms); 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate Acrylic acid hydroxyalkyl esters and methacrylic acid hydroxyalkyl esters (as the hydroxyalkyl group, for example, those having 1 to 20 carbon atoms); Unsaturated aliphatic carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid; Vinyl acetate; Combinations of these, and the like. Especially, since n-butyl acrylate and 2-ethylhexyl acrylate are used as a monomer, since adhesive characteristics, such as adhesive force, holding force, and adhesive force, are favorable, it is especially preferable. The said acrylic adhesive is manufactured by superposing | polymerizing these monomers by solution polymerization, block polymerization, emulsion polymerization, suspension polymerization, etc. by a conventional method in presence of a polymerization initiator. In particular, the emulsion-type acrylic pressure-sensitive adhesive obtained in emulsion polymerization is preferable because water is used as the main polymerization solvent, so that the safety during production of the pressure-sensitive adhesive sheet 1 can be reduced and the load on the global environment can be reduced.

The butyl rubber-based pressure-sensitive adhesive is usually equipped with butyl rubber, softener and tackifying resin.

The butyl rubber is obtained by isobutylene as a main component and copolymerizing 1-2 wt% of isoprene for crosslinking. Butyl rubber has the characteristic that gas permeability is extremely low. The butyl rubber is preferably crosslinked in order to improve the balance between adhesion and cohesion, and is vulcanized by polyalkylphenol resins, electron beam crosslinking, a photoinitiator and a photopolymerizable multifunctional monomer (for example, trimethylolpropane triacrylate). UV crosslinking by the addition of the same), and the like, and vulcanization with polyalkylphenol resins is preferable because the vulcanization catalyst required for the other rubber-based adhesive is unnecessary and heat resistance and non-pollution resistance are good.

The softener is added for the purpose of lowering the glass transition temperature of butyl rubber to improve initial adhesiveness at low temperatures, and to maintain a high balance of cohesion and adhesion. For example, petroleum-based compounds such as process oil and extender oil. ; Liquid rubbers such as liquid polyisobutylene, liquid polybutene and liquid polyisoprene; Dibasic acid ester plasticizers, such as a dibutyl phthalate and a dioctyl phthalate, etc. are mentioned.

The said tackifying resin is added for the purpose of improving initial adhesiveness, For example, rosin-type resins, such as rosin, modified rosin, rosin ester; Terpene resins such as terpene resins, aromatic modified terpene resins, hydrogenated terpene resins and terpene phenols; Petroleum resins such as aliphatic (C5) petroleum resins, aromatic (C9) petroleum resins, C5 / C9 copolymerized petroleum resins, cycloaliphatic petroleum resins, coumarone-indene resins and styrene petroleum resins; Phenol-based resins such as alkylphenol resins and rosin-modified phenol resins; Although all normal tackifying resins, such as xylene resin, are mentioned, A petroleum resin is preferable at the point that weather resistance is favorable.

A filler, an anti-aging agent, etc. may be added to the said butyl rubber type adhesive suitably in the range which does not inhibit the adhesive physical property etc., for example.

As the filler, for example, calcium carbonate; Magnesium carbonate; Calcium such as dolomite; Magnesium carbonate; Silicates such as kaolin, calcined clay, pyrophyllite, bentonite, sericite, zeolite, nephelin-signite, talc, attapalzite and wollastonite; Silicic acid such as diatomaceous earth, silica powder; Aluminum hydroxide; Barium sulfates such as barite and precipitated barium sulfate; Calcium sulfate such as gypsum; Calcium sulfite; Carbon black; Zinc oxide; Titanium dioxide and the like.

Examples of the antioxidants include phenolic antioxidants, amine antioxidants, imidazole antioxidants, dithiocarbamate antioxidants, phosphorus antioxidants, sulfur ester antioxidants, and the like.

As an adhesive which comprises the adhesive layer 3, it is preferable that it is an ultraviolet curable adhesive. Since the ultraviolet curable pressure sensitive adhesive is used as the pressure sensitive adhesive, the pressure sensitive adhesive sheet 1 is attached to the back surface of the solar cell module, and then the pressure sensitive adhesive layer 3 is exposed to sunlight to gradually cure ultraviolet rays, thereby increasing the strength of the pressure sensitive adhesive sheet 1. Can increase.

As the ultraviolet curable pressure sensitive adhesive, one containing an ultraviolet curable component in addition to the adhesive polymer component described above can be used, but one containing a ultraviolet curable polymer having a form in which an unsaturated double bond is added to the side chain of the adhesive polymer can also be used.

As an ultraviolet curable component, reaction by an ultraviolet curable component (for example, reaction of an ultraviolet curable component, reaction with an ultraviolet curable component, and another component (for example, acrylic polymer etc.) in an adhesive layer) by ultraviolet irradiation. Etc.] can be used. Specifically, as the ultraviolet curing component, a compound (monomer, oligomer or polymer, etc.) having at least one group (unsaturated double bond containing group) containing an unsaturated double bond in the molecule can be used, and in particular, a nonvolatile compound is suitable. Do. The ultraviolet curable component can be used individually or in combination of 2 or more types.

As an unsaturated double bond containing group in an ultraviolet curing component, especially the group containing a carbon-carbon double bond (carbon-carbon double bond containing group) is preferable, As this carbon-carbon double bond containing group, for example, And ethylenically unsaturated bond-containing groups such as a vinyl group, an allyl group, and a (meth) acryloyl group. An unsaturated double bond containing group can be used individually or in combination of 2 or more types. In addition, in one molecule of ultraviolet curing component, the number of unsaturated double bond-containing groups is preferably two or more. When the ultraviolet curing component has two or more unsaturated double bond containing groups in one molecule, two or more identical unsaturated double bond containing groups may be used, and 2 or more types of unsaturated double bond containing groups may be used.

As the ultraviolet curing component, for example, an esterified product of (meth) acrylate with a polyhydric alcohol, an ester acrylic compound, a urethane acrylic compound, a cyanurate compound having an unsaturated double bond containing group, or an iso having an unsaturated double bond containing group Cyanurate type compound etc. are mentioned.

As an ultraviolet curing component, More specifically, For example, Di (meth) acrylate [(meth) acrylic-acid di (alkylene glycol) ester of alkylene glycol; For example, di (meth) acrylate of tetraethylene glycol, di (meth) acrylate of polyethylene glycol, di (meth) acrylate of propylene glycol, di (meth) acrylate of polypropylene glycol, 1,4- C1-9 alkylene glycol or poly (C1-9 alkyl), such as di (meth) acrylate of butylene glycol, di (meth) acrylate of 1,6-hexanediol, and di (meth) acrylate of neopentyl glycol Ethylene glycol) di (meth) acrylate, etc.], 2-propenyl-di-3-butenyl cyanurate, di (meth) acrylate of tris (2-hydroxyethyl) isocyanurate, neopentyl Di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of glycol, di (meth) acrylate of bisphenol A or its modified body, di (meth) acrylate of trimethylolpropane or its modified product ( Meth) acrylate, trimethyl Tri (meth) acrylate of propane or its modified substance, trimethylolmethane tetra (meth) acrylate, tri (meth) acrylate of tris (2-hydroxyethyl) isocyanurate, pentaerythritol tree (meth) ) Acrylate, pentaerythritol tetra (meth) acrylate, poly (meth) acrylate of dipentaerythritol, caprolactone modified tris [(meth) acryloxyethyl] isocyanurate, caprolactone modified dipentaerythritol Poly (meth) acrylate, adipic acid neopentyl glycol modified di (meth) acrylate, hydroxy pivalate neopentyl glycol di (meth) acrylate, hydroxy pivalic acid ester modified neopentyl glycol di (meth) acrylic Latex, caprolactone modified hydroxy pivalate neopentyl glycol di (meth) acrylate, dioxane modified di (meth) acrylate, cyclopentanyldi (meth) acrylate , There may be mentioned ethylene oxide-modified phosphoric acid di (meth) acrylate, ethylene oxide-modified alkylated the di (meth) acrylate, alkyl-modified dipentaerythritol poly (meth) acrylate and the like.

Although it does not restrict | limit especially as a content rate of an ultraviolet curable component, For example, it is about 5-500 mass parts (preferably 10-200 mass parts) with respect to 100 mass parts of adhesive polymer components (acrylic resin etc.).

Moreover, additives, such as a photoinitiator and a crosslinking agent, may be mix | blended with an ultraviolet curable adhesive in addition to an adhesive polymer component and an ultraviolet curing component.

The photopolymerization initiator is not particularly limited as long as the photopolymerization initiator is activated by ultraviolet light and can cause a reaction of the ultraviolet curing component. Specifically, as a photoinitiator, an acetophenone type photoinitiator, a benzoin type photoinitiator, a benzyl type photoinitiator, a benzoin alkyl ether type photoinitiator, a benzophenone type photoinitiator, a ketal type photoinitiator, a thioxanthone type, Photoinitiators, α-ketol photoinitiators, aromatic sulfonyl chloride photoinitiators, photoactive oxime photoinitiators and the like can be used. A photoinitiator can be used individually or in combination of 2 or more types.

As a photoinitiator, an acetophenone type photoinitiator and a benzoin type photoinitiator are preferable. As an acetophenone type photoinitiator, 4-phenoxy dichloro acetophenone, 4-t-butyl- dichloro acetophenone, diethoxy acetophenone, 1-phenyl- 2-hydroxy-2- methyl propane-1-, Warm, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, and the like. As a benzoin type photoinitiator, benzoin etc. are mentioned, for example.

In addition, benzyl etc. are contained in a benzyl-type photoinitiator, for example. As a benzoin alkyl ether type photoinitiator, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. are mentioned, for example. As a benzophenone type photoinitiator, benzophenone, benzoyl benzoic acid, 3,3'- dimethyl- 4-methoxy benzophenone, polyvinyl benzophenone, (alpha)-hydroxycyclohexyl phenyl ketone, etc. are mentioned, for example. As a ketal type photoinitiator, benzyl dimethyl ketal etc. are mentioned, for example. As a thioxanthone type photoinitiator, for example, thioxanthone, 2-chloro thioxanthone, 2-methyl thioxanthone, 2, 4- dimethyl thioxanthone, isopropyl thioxanthone, 2, 4- dichloro thi Oxanthone, 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, dodecyl thioxanthone, etc. are mentioned.

Moreover, as said crosslinking agent, For example, polyisocyanate type crosslinking agent, melamine resin, urea resin, aziridine type compound, epoxy type crosslinking agent (epoxy resin etc.), low molecular compound which has two or more carboxyl groups, its anhydride, polyamine, and has two or more carboxyl groups Polymers and the like can be used.

According to the pressure sensitive adhesive sheet 1 for protecting the back surface of the solar cell module, the pressure sensitive adhesive sheet 1 is attached to the back surface of the back sheet on the back surface of the back surface of the solar cell module in which physical defects such as scratches and cracks are generated. In addition to preventing the ingress of water vapor from the defective portion, the expansion of the defective portion can be suppressed. In addition, according to the pressure-sensitive adhesive sheet for protecting the solar cell module back surface, since the pressure-sensitive adhesive layer 3 has a constant thickness, the pressure-sensitive adhesive layer is filled up to the maximum depth of physical defects that may normally occur in the back sheet. Inhibition of expansion and invasion into the solar cell module from the outside such as water vapor can be reliably prevented.

The solar cell module back surface protective adhesive sheet 11 of FIG. 2 has the base material layer 2, the adhesive layer 3 laminated | stacked on one surface side of this base material layer 2, and the other of this base material layer 2 The barrier layer 4 laminated | stacked on the surface side is provided. Since the base material layer 2 and the adhesive layer 3 are the same as the adhesive sheet 1 for solar cell module back surface protection of FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

The barrier layer 4 contains an inorganic substance. Although this inorganic substance will not be specifically limited if it has gas barrier property, It is preferable that it is an inorganic oxide. Since the barrier layer 4 contains an inorganic oxide, it can exhibit gas barrier properties such as high water vapor, and has insulation properties, so that even when a physical defect such as a crack occurs deeply in the back sheet, conductivity of a solar cell or a wiring can be maintained. It can protect the part which has.

The barrier layer 4 having the inorganic oxide may be formed by depositing an inorganic oxide on one surface of the base layer 2. The vapor deposition means is not particularly limited as long as an inorganic oxide can be deposited on the base material layer 2 made of synthetic resin without causing shrinkage or the like, and is not particularly limited. For example, (a) vacuum deposition, sputtering, ion plating, Physical vapor deposition methods such as ion cluster beam method (Physical Vapor Deposition method; PVD method), (b) chemical vapor deposition methods such as plasma chemical vapor growth method, thermochemical vapor growth method and photochemical vapor growth method (Chemical Vapor Deposition method; CVD Law) is adopted. Among these vapor deposition methods, the vacuum evaporation method and the ion plating method which can form the high quality barrier layer 4 are preferable.

The inorganic oxide constituting the barrier layer 4 is not particularly limited as long as it has gas barrier properties. For example, aluminum oxide, silica oxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, magnesium oxide, or the like is used. Among them, aluminum oxide or silica oxide having a good balance of gas barrier properties and price is particularly preferable.

When the barrier layer 4 is formed by vapor deposition of an inorganic oxide, the lower limit of the average thickness of the barrier layer 4 is preferably 3 GPa, particularly preferably 400 GPa. On the other hand, as an upper limit of the average thickness of the barrier layer 4 when the barrier layer 4 is formed by vapor deposition of an inorganic oxide, 3000 kPa is preferable and 800 kPa is especially preferable. If the average thickness of the barrier layer 4 is smaller than the said lower limit, there exists a possibility that gas barrier property may fall. On the other hand, when the average thickness of the barrier layer 4 exceeds the said upper limit, the flexibility of the barrier layer 4 will fall and defects, such as a crack, will arise easily.

In addition, the barrier layer 4 has aluminum as an inorganic substance, and may be formed by vapor deposition of aluminum. When the barrier layer 4 is formed by vapor deposition of aluminum, according to the pressure-sensitive adhesive sheet 1, since the gas barrier property is particularly high and the aluminum vapor deposition surface has a metallic luster, By reflecting the light beam passing through it for reuse, power generation efficiency can be improved.

As a method of forming the barrier layer 4 by vapor deposition of aluminum, the method similar to the vapor deposition method of the said inorganic oxide can be used. When the barrier layer 4 is formed by vapor deposition of aluminum, as a minimum of the average thickness of the barrier layer 4, 10 nm is preferable and 20 nm is especially preferable. On the other hand, as an upper limit of the thickness of the barrier layer 4 by aluminum vapor deposition, 200 nm is preferable and 100 nm is especially preferable. If the thickness of the barrier layer 4 is smaller than the said lower limit, there exists a possibility that gas barrier property may fall. On the contrary, when the thickness of the barrier layer 4 exceeds the above upper limit, defects such as cracks tend to occur in the barrier layer 4.

The barrier layer 4 may have a single layer structure or a multilayer structure of two or more layers. Thus, by making the barrier layer 4 into a multilayer structure, deterioration of the base material layer 2 is reduced by the reduction of the heat burden on vapor deposition, and also the adhesiveness of the base material layer 2 and the barrier layer 4, etc. are reduced. It can be improved. In addition, the vapor deposition conditions in the said physical vapor deposition method and the chemical vapor deposition method are suitably designed according to the kind of resin of the base material layer 2, the thickness of the barrier layer 4, etc.

In addition, the barrier layer 4 may be formed by the sol-gel method using the composition containing a metal alkoxide and / or its hydrolyzate. By forming the barrier layer 4 by such a sol-gel method, adhesiveness with the base material layer 2 becomes high and high gas barrier property can be exhibited. In addition, the barrier layer 4 can be formed at a relatively low temperature by forming by the sol-gel method which does not become as high as vapor deposition. Therefore, since the burden is not placed on the base material layer 2 which is not relatively strong at high temperatures, the multilayer barrier layer 4 can be easily formed.

Examples of the metal contained in the metal alkoxide include trivalent or higher metals, for example, transition metals, rare earth metals, metals in group 3 to 5 of the periodic table, and metals belonging to group 3b or group 4 in the periodic table. Do. As a metal which belongs to group 3b of periodic table, Al etc. are mentioned, for example. Examples of the metal belonging to group 4 of the periodic table include Si belonging to group 4b such as Ti and Zr belonging to group 4a. Among these metals, Al and Si are preferable, and Si is especially preferable, which is easy to form a film by a sol-gel method and is excellent in an interface planarization function.

As an alkoxy group which a metal alkoxide has, a methoxy group, an ethoxy group, a propoxy group, isopropoxy group, butoxy group, isobutoxy group, pentyloxy group, hexyloxy group, etc. are mentioned, for example. Especially, the C1-C4 lower alkoxy group which is excellent in hydrolytic polymerization property is preferable, and a methoxy group, an ethoxy group, and a propoxy group are especially preferable. Moreover, the metal alkoxide which has at least 2 alkoxy group is preferable for the purpose of promoting hydrolytic polymerization property.

The metal alkoxide may have a hydrocarbon group. As this hydrocarbon group, For example, Alkyl groups, such as a methyl group, an ethyl group, a propyl group, isopropyl group, a butyl group, a pentyl group, and a hexyl group; Cycloalkyl groups such as cyclopentyl group, cyclohexyl group and cyclooctyl group; Aryl groups, such as a phenyl group and a naphthyl group; Aralkyl groups, such as a benzyl group and 2-phenylethyl group, etc. are mentioned. Of these hydrocarbon groups, alkyl groups and aryl groups are preferred. Among these alkyl groups, lower alkyl groups having 1 to 4 carbon atoms are preferred, and methyl, ethyl and propyl groups are particularly preferred. Moreover, a phenyl group is preferable also in an aryl group. The number of hydrocarbon groups in the metal alkoxide can be appropriately selected depending on the number of alkoxy groups, and is generally about 0 to 2 in one molecule.

Specifically as a metal alkoxide, what is represented by following formula (1) is preferable.

(R ¹ ) _m M (OR ² ) _xm (1)

In said Formula (1), R <^1> may represent an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group, and may have a substituent. R ² represents a lower alkyl group. R ¹ and R ² may be different depending on m. M represents a trivalent or higher metal. X represents the valence of the metal (M). m represents the integer of 0-2, and Xm≥2.

Especially as a metal alkoxide whose metal is Si, what is represented by following formula (2) is preferable.

(R ¹ ) _n Si (OR ² ) _4-n (2)

In said formula (2), R <^1> represents an alkyl group or an aryl group, and may have a substituent. R ² represents a lower alkyl group. R ¹ and R ² may be different depending on n. n represents the integer of 0-2.

As a metal alkoxide whose metal is Al, a trimethoxy aluminate, a triethoxy aluminate, ethyl diethoxy aluminate, a tripropoxy aluminate, etc. are mentioned specifically ,.

Specific examples of the metal (Si) alkoxide represented by the formula (2) include tetramethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane and tetraethoxy. Silane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, tetrapropoxysilane, methyltripropoxysilane, ethyltripropoxysilane, dimethyldimethoxysilane, diethyl Dimethoxysilane, dipropyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-methcaptopropyltrimethoxysilane, γ -Mepcaptopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, phenyl trimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, diphenyldimethoxysil And the like, diphenyl diethoxy silane.

Among the metal (Si) alkoxides represented by the above formula (2), a compound having 0 to 2 alkyl groups or aryl groups having about 1 to 4 carbon atoms and 2 to 4 alkoxy groups having about 1 to 3 carbon atoms, for example, Tetramethoxysilane, Methyltrimethoxysilane, Ethyltrimethoxysilane, Methyltriethoxysilane, Tetraethoxysilane, Ethyltriethoxysilane, Diethyldiethoxysilane, Dimethyldiethoxysilane, Phenyltrimethoxysilane , Phenyltriethoxysilane and the like are particularly preferred.

In addition, in the said composition, 1 type (s) or 2 or more types can be used for the same or different types of metal alkoxides. Moreover, in the said composition, in order to adjust the rigidity, flexibility, etc. of a composition, you may add n = 3 monoalkoxysilane. Moreover, in the said composition, a compound of group 5b, for example, methyl phosphonus dimethyl ester, ethyl phosphorus dimethyl ester, trichloromethyl phosphorus diethyl ester, methyl phosphorus diethyl ester, and methyl phosphonic You may add phosphorus compounds, such as a dimethyl ester, a phenyl phosphonic dimethyl ester, and phosphoric acid trialkyl ester, and boron compounds, such as a boric acid trialkyl ester. Moreover, in the said composition, you may add the alkaline earth metal compound which has at least 1 hydrolysable organic group as needed. This alkaline earth metal compound may have both a hydrocarbon group and a hydrolyzable organic group.

The composition may contain a metal alkoxide (A) having a functional group containing at least one of nitrogen, oxygen, sulfur and halogen. Thus, by coating and curing a composition containing a metal alkoxide (A) having a functional group containing at least one of nitrogen, oxygen, sulfur, and halogen, a specific polysiloxane structure is expressed in the barrier layer 4, thereby providing a barrier layer ( The film physical properties of 4) can further improve the gas barrier properties, and at the same time, the temperature dependence of the gas barrier properties of the barrier layer 4 can be reduced.

As a functional group containing at least 1 of the said nitrogen, oxygen, sulfur, and halogen, an amino group, a chlorine, a mercapto group, glycidoxy group, etc. are mentioned, for example. As a metal alkoxide (A) which has a functional group containing at least 1 of the said nitrogen, oxygen, sulfur, and halogen, For example, (gamma) -chloropropyl trimethoxysilane, (beta)-(3, 4- epoxycyclohexyl) ethyl. Trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methcaptopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltri Methoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane, bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ -Aminopropyl silicone, etc. can be mentioned, 1 type, or 2 or more types can be used among these metal alkoxides.

As content (content with respect to all the metal alkoxides in a composition) of the said metal alkoxide (A), 1 mass% or more and 50 mass% or less are preferable, and 3 mass% or more and 30 mass% or less are especially preferable. By making content of a metal alkoxide (A) into the said range, the polysiloxane structure which contributes to gas barrier property to the barrier layer 4 can be expressed.

What is necessary is just to contain a solvent-soluble polymer in the said composition. By forming the barrier layer 4 by the sol-gel method using the composition containing such a solvent-soluble polymer and a metal alkoxide, the film | membrane property of the barrier layer 4 improves and also the gas barrier property of the barrier layer 4 ( In particular, gas barrier property at the time of high temperature can be improved more.

Examples of the solvent-soluble polymer include polymers having various functional groups and functional bonding groups (for example, hydroxyl groups, carboxyl groups, ester bonds, ether bonds, carbonate bonds, amide groups, amide bonds, and the like), polymers having glycidyl groups, and halogens. Containing polymers, derivatives of these polymers, and the like. These functional groups and functional linking groups may be present in the main chain or the side chain of the polymer. As a solvent-soluble polymer, any of a thermoplastic resin or a thermosetting resin may be sufficient, and you may use individually or in mixture of 2 or more types. In addition, as a solvent-soluble polymer, although it may be active or inert in reaction with a metal alkoxide, it is generally a non-reactive polymer. In addition, an "amide bond" is not limited to -NHC (O)-, It is a concept containing a> NC (O)-coupling unit.

Examples of the polymer having a hydroxyl group and derivatives thereof include polyvinyl alcohol, polyvinyl acetal, ethylene-vinyl alcohol copolymer, phenol resin, methylolmelamine and the like and derivatives thereof (for example, acetalide and hexame Oxymethyl melamine, etc.) is mentioned. As said polymer which has the said carboxyl, and its derivative (s), For example, the homopolymer or copolymer containing units of polymerizable unsaturated acids, such as poly (meth) acrylic acid, maleic anhydride, itaconic acid, esterified products of these polymers, etc. are mentioned. Can be mentioned. As a polymer which has the said ester bond, the homopolymer or copolymer (for example, polyvinyl acetate, ethylene) containing units, such as vinyl esters, such as vinyl acetate, and (meth) acrylic acid ester, such as methyl methacrylate, for example Vinyl acetate copolymers, (meth) acrylic resins, and the like), saturated polyesters, unsaturated polyesters, vinyl ester resins, diallyl phthalate resins, cellulose esters, and the like. As a polymer which has the said ether bond, polyalkylene oxide, polyoxyalkylene glycol, polyvinyl ether, a silicon resin etc. are mentioned, for example. Examples of the polymer having a carbonate bond include polycarbonates such as bisphenol A polycarbonate.

As a polymer which has the said amide bond, For example, N-acyl compounds, such as polyoxazoline and polyalkylene imine which have> N (COR)-bond; Polyvinylpyrrolidone having> NC (O)-bonds and derivatives thereof; Polyurethane with a urethane bond -HNC (O) O-; Polymers having urea bonds —HNC (O) NH—; Polymers having an amide bond -C (O) NH-; Polymers with burette bonds; Polymers having allophanate bonds and the like. In the above formula, R represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent.

In the case of polyoxazoline having> N (COR)-bond, as the alkyl group represented by R, for example, an alkyl group having about 1 to 10 carbon atoms, preferably a lower alkyl group having 1 to 4 carbon atoms, particularly a methyl group or an ethyl group , Propyl group and isopropyl group. As a substituent of an alkyl group, halogen atoms, such as fluorine, chlorine, and bromine, a hydroxyl group, the C1-C4 alkoxy group, a carboxyl group, the C1-C4 alkoxycarbonyl group etc. are mentioned, for example. have. As an aryl group, a phenyl, a naphthyl group, etc. are mentioned, for example. As a substituent of an aryl group, the said halogen atom, a C1-C4 alkyl group, a hydroxyl group, a C1-C4 alkoxy group, a carboxyl group, a C1-C4 alkoxycarbonyl group etc. are mentioned, for example. Can be mentioned.

Examples of oxazolines include 2-oxazoline, 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-isopropyl-2-oxazoline, 2-butyl-2-oxazoline, 2-dichloromethyl-2-oxazoline, 2-trichloromethyl-2-oxazoline, 2-pentafluoroethyl-2-oxazoline, 2-phenyl-2-oxazoline , 2-methoxycarbonylethyl-2-oxazoline, 2- (4-methylphenyl) -2-oxazoline, 2- (4-chlorophenyl) -2-oxazoline, etc. are mentioned. In particular, 2-oxazoline, 2-methyl-2-oxazoline, 2-ethyl- 2-oxazoline, etc. are preferable. Such oxazoline polymer can be used 1 type or in mixture of 2 or more types. The polyoxazoline may be a homopolymer or a copolymer. The polyoxazoline may be a copolymer obtained by grafting polyoxazoline to a polymer.

In addition, polyoxazoline is obtained by ring-opening-polymerizing oxazoline which may have a substituent in presence of a catalyst. As a catalyst, For example, sulfate esters, such as dimethyl sulfate and p-toluenesulfonic acid alkyl ester, and sulfonic acid ester; Halogenated alkyl such as alkyl iodide (for example, methyl iodide); Metal fluorides in Friedel-Crafts catalysts; Acids, such as a sulfuric acid, hydrogen iodide, and p-toluenesulfonic acid, an oxazolinium salt which is a salt of these acids and oxazoline, etc. can be used.

As an acylate of polyalkylene imine, the polymer corresponding to the said polyoxazoline, for example, the polymer which has N-acylamino groups, such as N-acetylamino and N-propionylamino, is mentioned. As polyvinylpyrrolidone and its derivatives, the polymer of vinylpyrrolidone which may have a substituent, for example, polyvinylpyrrolidone, etc. are mentioned. As a polyurethane which has a urethane bond, For example, Polyisocyanate (tolylene diisocyanate, hexamethylene diisocyanate etc.) and polyol (polyhydric alcohols, such as ethylene glycol, propylene glycol, tetramethylene glycol, glycerin; diethylene glycol, polyethylene Polyurethane produced | generated by reaction with polyether polyol, such as glycol, dipropylene glycol, polypropylene glycol, polyester polyol, etc.) is mentioned. As a polymer which has a urea bond, the polymer etc. which are produced | generated by reaction of polyurea, a polyisocyanate, and a polyamine (for example, diamines, such as ethylenediamine and diethylenetriamine) are mentioned.

Examples of the polymer having an amide bond include polyamide, poly (meth) acrylamide, polyamino acid, and the like. As a polymer which has this amide bond, the oxazoline polymer which may have a substituent, the N-acylide of polyalkylene imine, polyvinylpyrrolidone, a polyurethane, a polyamide, a poly (meth) acrylamide, etc. are preferable. As a polymer which has a biuret bond, the polymer produced | generated by reaction of the said polyisocyanate and the compound which has a urethane bond is mentioned. As a polymer which has an allophanate bond, the polymer etc. which are produced | generated by reaction of the said polyisocyanate and the compound which has a urea bond are mentioned. As a polymer which has a glycidyl group, an epoxy resin, the homopolymer of a glycidyl (meth) acrylate, or a copolymer etc. are mentioned, for example. Examples of the halogen-containing polymer include polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, vinylidene chloride polymers having a unit of vinylidene chloride, chlorinated polypropylene, and the like.

Solvent soluble polymers are generally water; Alcohols such as methanol, ethanol, propanol, isopropanol, butanol and cyclohexanol; Aliphatic hydrocarbons such as hexane and octane; Alicyclic hydrocarbons such as cyclohexane; Aromatic hydrocarbons such as benzene, toluene and xylene; Halogenated hydrocarbons such as methyl chloride, methylene chloride, chloroform and trichloroethylene; Esters such as methyl acetate, ethyl acetate and butyl acetate; Ketones such as acetone and methyl ethyl ketone; Ethers such as diethyl ether, dioxane, dimethoxyethane and tetrahydrofuran; Nitrogen-containing solvents (for example, nitriles such as N-methylpyrrolidone and acetonitrile, amides such as dimethylformamide and dimethylacetamide), sulfoxides (for example, dimethyl sulfoxide and the like) Aprotic polar solvents; Or soluble in these mixed solvents.

As a solvent-soluble polymer, what has a hydrogen bondable group, for example, a hydroxyl group, a carboxyl group, an amide group, an amide bond, a nitrogen atom, etc. is preferable. When the solvent soluble polymer which has such a hydrogen bondable group is used, the solvent common to metal alkoxide and / or its hydrolyzate can be used in many cases, and the organometallic polymer produced | generated by the hydrolysis polymerization of a metal alkoxide can be used. It is considered that the functional group and the bonding group of the hydroxyl group and the solvent-soluble polymer are hydrogen bonded, and as a result, a uniform organic / inorganic hybrid can be formed to form a micro homogeneous and transparent film.

Moreover, as a solvent soluble polymer, the alcohol soluble polymer which can use a common solvent with a metal alkoxide is preferable. As such an alcohol-soluble polymer, water-soluble polymers, such as a polymer which has a hydroxyl group, are preferable, and the polymer which has a nitrogen atom (for example, the polymer which has the said amide bond) is especially preferable.

40 mass% or more and 90 mass% or less are preferable, and, as for content with respect to 100 mass parts of metal alkoxides (including the hydrolyzate) of a solvent-soluble polymer, 50 mass% or more and 80 mass% or less are especially preferable. When content of a solvent-soluble polymer is smaller than the said range, the gas barrier property improvement effect may fall and it may become difficult to form a uniform film by the composite of an inorganic polymer and an organic polymer. On the other hand, when content of a solvent-soluble polymer exceeds the said range, although film formability and uniformity show a tendency to become high, there exists a possibility that gas barrier property may fall.

In the said composition, the organic solvent is generally mix | blended. As the organic solvent, a suitable solvent which is inert to the polymerization reaction depending on the type of metal alkoxide, for example, alcohols, aromatic hydrocarbons, ethers, nitrogen-containing solvents, sulfoxides, mixed solvents thereof, or the like is used. Moreover, the said solvent soluble polymer can also be used as an organic solvent. As this organic solvent, the solvent which has miscibility with the solvent of a metal alkoxide is preferable, and the good solvent common to solvent soluble polymer and a metal alkoxide is especially preferable.

Moreover, in the said composition, a curing catalyst is included and you may perform hydrolysis polymerization of a metal alkoxide in presence of a curing catalyst. As the curing catalyst, tertiary amines, acid catalysts and the like which are substantially insoluble in water and soluble in organic solvents are used. As tertiary amines, N.N-dimethylbenzylamine, tripropylamine, tributylamine, tripentylamine, etc. are mentioned, for example. As an acid catalyst, For example, inorganic acids, such as hydrochloric acid, a sulfuric acid, nitric acid, phosphoric acid; For example, organic acids, such as carboxylic acid, such as formic acid, an acetic acid, trichloroacetic acid, trifluoroacetic acid, and propionic acid, sulfonic acids, such as methanesulfonic acid, an ethanesulfonic acid, and p-toluenesulfonic acid, are mentioned.

Moreover, in the composition which forms the barrier layer 4 by the sol-gel method, various additives, such as a plasticizer, antioxidant, a ultraviolet absorber, a flame retardant, an antistatic agent, surfactant, a filler, a coloring agent, may be mix | blended suitably as needed. .

Next, the formation method of the barrier layer 4 by a sol-gel method is demonstrated. The composition is adjusted by appropriately adding a solvent-soluble polymer, a curing catalyst, an organic solvent, and the like to the metal alkoxide and / or its hydrolyzate, and kneading it sufficiently, and the composition is coated on the surface of the base layer 2 by a conventional coating method. It coats, and it heat-drys then, performs an aging process, etc., and forms the barrier layer 4 which is a coating cured film. As this heating temperature, although it selects suitably according to the hydrolysis property of a metal alkoxide, and the heat resistance of the base material layer 2, 50 degreeC or more and 120 degrees C or less are preferable. In addition, a polymerization reaction may be performed in presence of an inert gas, and may be performed under reduced pressure. Moreover, you may superpose | polymerize, removing the alcohol produced with hydrolysis polymerization.

In the formation method of the barrier layer 4 by the said sol-gel method, ultraviolet irradiation to a composition may be performed at the time of a heating process. Thus, by irradiating the composition with ultraviolet rays during the heating step of the sol-gel method, the composition is cured at a lower temperature (100 ° C. or lower), and the barrier layer 4 is significantly less deficient, resulting in excellent film properties. The adhesiveness of the layer 4 and the base material layer 2 improves. Therefore, the gas barrier property of the barrier layer 4 can be improved more.

Moreover, what is necessary is just to surface-treat on one surface of the base material layer 2, in order to improve the adhesiveness of the base material layer 2 and the barrier layer 4, etc. Examples of such adhesion-enhancing surface treatment include (a) low temperature plasma treatment using corona discharge treatment, ozone treatment, oxygen gas or nitrogen gas, glow discharge treatment, chemicals and the like, and (b) primers. Coat treatment, undercoat treatment, anchor coat treatment, vapor deposition anchor coat treatment, and the like. Among these surface treatments, the corona discharge treatment and the anchor coat treatment which improve the adhesive strength with the barrier layer 4 and contribute to the formation of the dense and uniform barrier layer 4 are preferable.

As the anchor coat agent used for the anchor coat treatment, for example, polyester anchor coat agent, polyamide anchor coat agent, polyurethane anchor coat agent, epoxy anchor coat agent, phenolic anchor coat agent, (meta A polyolefin anchor coat agent, such as an acrylic anchor coat agent, a polyvinyl acetate type anchor coat agent, polyethylene, or a polypropylene, a cellulose anchor coat agent, etc. are mentioned. Among these anchor coat agents, a polyester anchor coat agent capable of further improving the adhesive strength between the base material layer 2 and the barrier layer 4 is particularly preferable.

As a minimum of the coating amount (solid content conversion) of the said anchor coat agent, 0.1 g / m <^2> is preferable and 1 g / m <^2> is especially preferable. On the other hand, as an upper limit of the coating amount of the said anchor coat agent, 5 g / m <^2> is preferable and 3 g / m <^2> is especially preferable. When the coating amount of the anchor coat agent is smaller than the lower limit, there is a fear that the effect of improving the adhesion between the base material layer 2 and the barrier layer 4 becomes small. On the other hand, when the coating amount of the said anchor coat agent exceeds the said upper limit, there exists a possibility that the intensity | strength, durability, etc. of the adhesive sheet 1 for back surface protection of the said solar cell module may fall.

In the anchor coat agent, various additives such as a silane coupling agent for improving adhesion and an antiblocking agent for preventing blocking with the base material layer 2 and an ultraviolet absorber for improving weather resistance and the like may be appropriately mixed. Can be. As a mixed amount of such an additive, 0.1 mass% or more and 10 mass% or less are preferable from the balance of the effect expression of an additive, and the function inhibition of an anchor coat agent.

Moreover, what is necessary is just to perform a topcoat process to one surface (outer surface which is not in contact with the base material layer 2) of the barrier layer 4. By applying the top coat treatment to the outer surface of the barrier layer 4 in this manner, the barrier layer 4 is sealed and protected, and as a result, the handleability of the pressure sensitive adhesive sheet 11 is improved, and the barrier layer 4 is applied to the barrier layer 4. Even if there are defects such as scratches and recesses, deterioration of the gas barrier property is suppressed, and aging deterioration of the barrier layer 4 is reduced. As a topcoat agent used for the said topcoat process, the thing similar to what is used for the base material layer 2 can be used.

As a minimum of the coating amount (solid content conversion) of the said topcoat agent, 1 g / m <^2> is preferable and 3 g / m <^2> is especially preferable. On the other hand, as an upper limit of the coating amount of the said topcoat agent, 10 g / m <^2> is preferable and 7 g / m <^2> is especially preferable. When the coating amount of the top coat agent is smaller than the lower limit, there is a fear that the effect of sealing and protecting the barrier layer 4 is reduced. On the other hand, even if the coating amount of the top coat agent exceeds the upper limit, the sealing and protecting effect of the barrier layer 4 does not increase so much, but rather the thickness of the pressure-sensitive adhesive sheet 11 increases, so that the request for thinning and weight reduction is required. There is a risk of falling.

Moreover, in the said top coat agent, various additives, such as a silane coupling agent for improving adhesiveness, an ultraviolet absorber for improving weather resistance, etc., an inorganic filler for improving heat resistance, etc. can be mixed suitably. As a mixed amount of such an additive, 0.1 mass% or more and 10 mass% or less are preferable from the balance between the effect expression of an additive, and the function inhibition of a topcoat agent.

Since the adhesive sheet 11 for back surface protection of the solar cell module is equipped with the barrier layer 4 laminated | stacked on the other surface side of the base material layer 2 in this way, it has high gas barrier property and also provides mechanical strength. Can be improved. Moreover, since the said adhesive sheet 11 for back surface protection of a solar cell module has high insulation, when the barrier layer 4 has an inorganic oxide, even when a deep physical defect arises in a back sheet, a solar cell and wiring The electroconductive part, such as these, can be protected.

The solar cell module back surface protective adhesive sheet 21 of FIG. 3 has the base material layer 2, the adhesive layer 3 laminated | stacked on one surface side of this base material layer 2, and the other of this base material layer 2 The barrier layer 5 laminated | stacked on the surface side, and the adhesive bond layer 6 laminated | stacked between the base material layer 2 and the barrier layer 5 are provided. Since the base material layer 2 and the adhesive layer 3 are the same as the adhesive sheet 1 for solar cell module back surface protection of FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

As the barrier layer 5, aluminum foil is used. Aluminum or an aluminum alloy is mentioned as a material of this aluminum foil, and aluminum-iron type alloy (soft material) is preferable. As iron content in this aluminum iron alloy, 0.3% or more and 9.0% or less are preferable, and 0.7% or more and 2.0% or less are especially preferable. When this iron content is less than the said minimum, there exists a possibility that the effect of the prevention of pinhole generation may become inadequate, On the contrary, when iron content exceeds the said upper limit, flexibility may be impaired and workability may fall. . Moreover, as a material of aluminum foil, the flexible aluminum which performed the annealing process from the viewpoint of preventing a pinhole is preferable.

As a minimum of thickness (average thickness) of aluminum foil, 6 micrometers is preferable and 15 micrometers is especially preferable. On the other hand, as an upper limit of the thickness of an aluminum foil, 30 micrometers is preferable and 20 micrometers is especially preferable. When the thickness of the aluminum foil is smaller than the lower limit, breakage of the aluminum foil is likely to occur at the time of processing, and there is a fear that the gas barrier property is lowered due to pinholes or the like. On the other hand, when the thickness of aluminum foil exceeds the said upper limit, there exists a possibility that a crack etc. may arise at the time of processing, and the thickness and weight of the adhesive sheet 21 for back surface protection of the said solar cell module increase, and it meets the social request of ultra-light weight reduction. Done.

The surface of the aluminum foil may be subjected to surface treatment such as chromate treatment, phosphate treatment, lubricity resin coating treatment, etc., from the viewpoint of preventing dissolution and corrosion, and coupling treatment or the like from the viewpoint of promoting adhesion. You may be. In addition, in order to increase the surface area and to exert a high heat dissipation function from the surface, the aluminum foil may form minute unevenness by embossing or the like.

Moreover, on one surface (surface of the side which is not in contact with the adhesive layer 6) of the aluminum foil which is the barrier layer 5, it is similar to the barrier layer 4 of the adhesive sheet 11 for solar cell module back surface protections. It is good to perform a coat process. By applying the top coat treatment to the outer surface of the barrier layer 5 as described above, the barrier layer 5 is sealed and protected, and as a result, the handleability of the adhesive sheet 21 is improved, and the barrier layer 5 is scratched, Even if there are defects such as recesses, deterioration of gas barrier properties is suppressed, and deterioration of the barrier layer 5 is reduced.

Although it does not specifically limit as an adhesive agent which comprises the adhesive bond layer 6, The adhesive agent for laminates or melt-extrusion resin is used suitably. As this adhesive agent for laminates, the adhesive agent for dry laminates, the adhesive agent for wet laminates, the adhesive agent for hot melt laminates, the adhesive agent for non-solvent laminates, etc. are mentioned, for example. Among these adhesives for lamination, the adhesive for dry lamination having excellent adhesive strength, durability, weather resistance, etc., and having a function of sealing and protecting defects (for example, scratches, pinholes, recesses, etc.) on the surface of the base material layer 2. Is particularly preferred.

As said dry lamination adhesive, For example, a polyvinyl acetate type adhesive agent, homopolymers, such as ethyl, butyl, 2-ethylhexyl ester of acrylic acid, or a copolymer of these and methyl methacrylate, acrylonitrile, styrene, etc. Ethylene copolymer type adhesive agent consisting of a polyacrylic acid ester adhesive, a cyanoacrylate adhesive, a copolymer of ethylene and a monomer such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, cellulose adhesive, polyester adhesive Amino resin adhesive consisting of adhesive, polyamide adhesive, polyimide adhesive, urea resin, melamine resin, etc., phenol resin adhesive, epoxy adhesive, polyurethane adhesive, reactive (meth) acrylic adhesive, chloroprene rubber, nitrile rubber, Styrene-butadiene rubber etc And inorganic adhesives made of rubber adhesives, silicone adhesives, alkali metal silicates, low melting glass, and the like. Among these dry laminate adhesives, the adhesive strength decrease and delamination resulting from long-term use of the solar cell module back surface protective adhesive sheet 21 for a long time are prevented, and deterioration such as yellowing of the adhesive layer 6 is reduced. Polyurethane adhesives, in particular polyester urethane adhesives, are preferred. Moreover, as a hardening | curing agent, aliphatic polyisocyanate with little thermal yellowing is preferable.

Examples of the melt-extruded resin include polyethylene-based resins, polypropylene-based resins, acid-modified polyethylene-based resins, acid-modified polypropylene-based resins, ethylene-acrylic acid or methacrylic acid copolymers, sulfine-based resins, and ethylene-vinyl acetate. One kind or two or more kinds of thermoplastic resins such as copolymers, polyvinyl acetate resins, ethylene-acrylic acid esters or methacrylic acid ester copolymers, polystyrene resins, and polyvinyl chloride resins can be used. In addition, when employing the extrusion lamination method using the melt-extruded resin, in order to obtain stronger adhesive strength, the surface treatment such as the above anchor coat treatment may be performed on the laminated opposing surface of the respective films.

As a minimum of lamination amount (solid content conversion) of the adhesive bond layer 6, 1 g / m <^2> is preferable and 3 g / m <^2> is especially preferable. On the other hand, as an upper limit of the laminated amount of the adhesive bond layer 6, 10 g / m <^2> is preferable and 7 g / m <^2> is especially preferable. When the laminated amount of the adhesive bond layer 6 is smaller than the said lower limit, there exists a possibility that adhesive strength and the defect sealing function of the barrier layer 4 may not be obtained. On the other hand, when the laminated amount of the adhesive bond layer 6 exceeds the said upper limit, there exists a possibility that laminated strength and durability may fall.

In addition, in the adhesive for laminate or melt-extruded resin forming the adhesive layer 6, for the purpose of improving and modifying the handleability, heat resistance, weather resistance, mechanical properties, and the like, for example, a solvent, a lubricant, a crosslinking agent, an antioxidant, and an ultraviolet ray Various additives such as absorbents, light stabilizers, fillers, reinforcing fibers, reinforcing agents, antistatic agents, flame retardants, flame retardants, foaming agents, mold inhibitors, and pigments can be mixed as appropriate.

Since the adhesive sheet 21 for back surface protection of the solar cell module uses aluminum foil for the barrier layer 5, the gas barrier property and mechanical strength, such as water vapor, are further improved, and the heat dissipation effect is high because of the high thermal conductivity of aluminum, By suppressing the temperature rise of the solar cell, it is possible to further promote the long life of the solar cell module.

The solar cell module back surface protective adhesive sheet 31 of FIG. 4 has the base material layer 2, the adhesive layer 3 laminated | stacked on one surface side of this base material layer 2, and the other of this base material layer 2 A first barrier layer 4 laminated on the surface side and containing an inorganic substance, an adhesive layer 6 laminated on one surface of the first barrier layer 4 (a side of the side not in contact with the base layer 2), 2nd barrier layer 5 which is laminated | stacked on one surface (surface of the side which is not in contact with the 1st barrier layer 4) of the adhesive bond layer 6, and consists of aluminum foil. The base material layer 2 and the pressure-sensitive adhesive layer 3 are the same as the pressure-sensitive adhesive sheet 1 for protecting the solar cell module back surface of FIG. 1, and the first barrier layer 4 containing inorganic material is the solar cell module back surface of FIG. 2. Since the 2nd barrier layer 5 and the adhesive bond layer 6 which are the same as a protective adhesive sheet, and consist of aluminum foil are the same as that of the solar cell module back surface protective adhesive sheet of FIG. 3, it attaches | subjects the same code | symbol and abbreviate | omits description.

Thus, since the adhesive sheet 31 for solar cell module back surface protection has two barrier layers 4 and 5 via the adhesive bond layer 6, it has the extremely high vapor barrier function and mechanical strength. Moreover, even if defects, such as a pinhole, a crystalline system, a crack, exist in the surface of the inner side barrier layer 4, since the adhesive bond layer 6 covers such surface defects, the said adhesive sheet 31 is a gas with respect to water vapor | steam etc. The barrier property is remarkably improved.

The solar cell module back surface protective adhesive sheet 41 of FIG. 5 has the base material layer 2, the adhesive layer 3 laminated | stacked on one surface side of this base material layer 2, the base material layer 2, and the adhesive layer ( The barrier layer 4 laminated | stacked between 3) is provided. The base material layer 2 and the pressure-sensitive adhesive layer 3 are the same as the pressure-sensitive adhesive sheet 1 for protecting the solar cell module back surface of FIG. 1, and the first barrier layer 4 containing the inorganic material is the rear surface of the solar cell module of FIG. 2. Since it is the same as a protective adhesive sheet, it attaches | subjects the same number and abbreviate | omits description.

According to the adhesive sheet 41 for protecting the back surface of the solar cell module, since the barrier layer 4 is provided similarly to the adhesive sheet 11 for protecting the back surface of the solar cell module, it has high gas barrier property and mechanical Strength can be improved. Moreover, since the barrier layer 4 is laminated | stacked between the base material layer 2 and the adhesive layer 3, the adhesive sheet 41 for back surface protection of the said solar cell module does not topcoat-process, etc. the barrier layer 4, or the like. Since it can protect, manufacture is easy, and generation | occurrence | production of the defect of the barrier layer 4, etc. can be suppressed, and physical durability improves.

In these solar cell module back surface protective adhesive sheets 1, 11, 21, 31, and 41, one side of the adhesive layer 3 (base layer 2, adhesive sheet 41, and barrier layer 4 and It is preferable that the surface of the side which is not in contact with is coated with a release sheet. According to the said adhesive sheet for back surface protection of a solar cell module, since one surface is coat | covered with a release sheet, since the adhesive layer can be prevented from contacting another until just before sticking work, workability becomes high and sticking The adhesion function of the adhesive sheet at the time can be improved.

Although it does not specifically limit as this release sheet, Synthetic resin films, such as polyethylene, a polypropylene, an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, a polyethylene terephthalate, a rubber sheet, paper, a cloth, a nonwoven fabric, a net, a foam sheet , A suitable film body made of metal foil or a laminate thereof can be used. In order to improve the peelability from the adhesive layer 3, it is preferable to perform peeling processes, such as a silicone treatment, a long chain alkyl treatment, a fluorine treatment, on the surface of a release sheet as needed. The peelability of a peeling sheet can be controlled by adjusting the kind of chemical | medical agent used for a peeling process, and / or its coating amount.

The solar cell module 51 of FIG. 6 includes a light transmissive substrate 52, a filler layer 53, a plurality of solar cell cells 54, a filler layer 55, a back sheet 56, The solar cell module back surface protective adhesive sheet 1 is laminated in this order from the surface side, and a part of the back surface of the back sheet 56 has both terminals of the wiring 57 for connecting each solar cell 54. The junction box 58 is provided.

The light-transmissive substrate 52 is laminated on the outermost surface, (a) having a permeability and electrical insulation against sunlight, (b) mechanical, chemical and physical strength, specifically weather resistance, heat resistance, durability, water resistance, It is desired to have excellent gas barrier properties, wind pressure resistance, chemical resistance, and fastness against water vapor, and (c) a high surface hardness and excellent antifouling property to prevent accumulation of dirt and dust on the surface.

Glass and synthetic resin are used as a forming material of the light transmissive substrate 52. As a synthetic resin used for the translucent board | substrate 52, polyethylene-type resin, a polypropylene resin, cyclic polyolefin resin, fluorine resin, polystyrene resin, an acrylonitrile-styrene copolymer (AS resin), acrylic Ronitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin such as polyethylene terephthalate, polyethylene naphthalate, various nylon Polyamide resin, polyimide resin, polyamideimide resin, polyaryl phthalate resin, silicone resin, polyphenylene sulfide resin, polysulfone resin, acetal resin, polyether sulfone resin, poly Urethane resin, cellulose resin, and the like. Among these resins, fluorine resin, cyclic polyolefin resin, polycarbonate resin, poly (meth) acrylic resin or polyester resin is particularly preferable.

In the case of the transparent resin substrate 52 made of synthetic resin, (a) inorganic oxides such as silicon oxide and aluminum oxide are transparent to one surface thereof by the PVD method or the CVD method for the purpose of improving gas barrier properties and the like. Laminating the deposited film, (b) to improve and modify workability, heat resistance, weather resistance, mechanical properties, dimensional stability, etc., for example, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, antistatic agents, light stabilizers, fillers It is also possible to contain various additives such as reinforcing fibers, reinforcing agents, flame retardants, flame retardants, foaming agents, mold inhibitors, and pigments.

It does not specifically limit as thickness (average thickness) of the translucent board | substrate 52, It selects suitably to have required intensity | strength, gas barrier property, etc. according to the material to be used. As thickness of the translucent board | substrate 32 made from synthetic resin, 6 micrometers or more and 300 micrometers or less are preferable, and 9 micrometers or more and 150 micrometers or less are especially preferable. Moreover, as thickness of the transparent substrate 52 made of glass, it becomes about 3 mm generally.

The filler layer 53 and the filler layer 55 are filled around the solar cell 54 between the light transmissive substrate 52 and the back sheet 56, and (a) the light transmissive substrate 52 and the bag. It has adhesiveness with the sheet 56, scratch resistance for protecting the solar cell 54, shock absorption, and the like. In addition, the filler layer 53 laminated on the surface of the solar cell 54 has the above various functions and transparency to transmit sunlight.

Examples of the material for forming the filler layer 53 and the filler layer 55 include fluorine resin, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid or methacrylic acid copolymer, polyethylene resin, polypropylene resin, Acid-modified polyolefin resin, polyvinyl butyral resin, silicone resin, epoxy resin, (meth) acrylic resin etc. which modified | denatured polyolefin resin, such as polyethylene, with unsaturated carboxylic acid, such as acrylic acid, are mentioned. Among these synthetic resins, fluorine-based resins, silicone-based resins or ethylene-vinyl acetate-based resins excellent in weather resistance, heat resistance, gas barrier properties and the like are preferable.

Moreover, as a formation material of the filler layer 53 and the filler layer 55, the thermoreversible crosslinkable olefin type polymer composition disclosed by Unexamined-Japanese-Patent No. 2000-34376, Specifically, (a) unsaturated carboxylic anhydride and unsaturated carbon As a modified olefin polymer modified by an acid ester, the average number of bonds of the carboxylic acid anhydride group per molecule is one or more, and the carboxylic acid ester group to the number of carboxylic acid anhydride groups in the modified olefin polymer. (B) with respect to the number of carboxylic acid anhydride groups of the component (a) containing a modified olefin polymer having a number ratio of 0.5 to 20 and (b) an average number of bonds of hydroxyl groups per molecule per molecule The thing of the ratio of the hydroxyl group number of components is 0.1-5, etc. are also used.

In addition, the material for forming the filler layer 53 and the filler layer 55 includes, for example, a crosslinking agent, a thermal antioxidant, a light stabilizer, an ultraviolet absorber, and a photooxidation for the purpose of improving weather resistance, heat resistance, gas barrier properties, and the like. Various additives, such as an inhibitor, can be contained suitably. The thickness of the filler layer 53 and the filler layer 55 is not particularly limited, but is preferably 200 µm or more and 1000 µm or less, particularly preferably 350 µm or more and 600 µm or less.

The solar cell 54 is a photovoltaic device that converts light energy into electrical energy, and is arranged between the filler layer 53 and the filler layer 55. The plurality of solar cells 54 are laid in substantially the same plane and are wired in series or in parallel. As the solar cell 54, for example, a crystalline silicon solar cell element such as a single crystal silicon solar cell element, a polycrystalline silicon solar cell element, an amorphous silicon solar cell element comprising a single junction type or tandem structure type, Group 3 to Group 5 compound semiconductors, such as gallium arsenide (GaAs) and Indium phosphorus (InP), and Group 2 to Group 6 compound semiconductors such as cadmium tellurium (CdTe) and copper indium selenide (CuInSe ₂ ). A solar cell element etc. can be used and these hybrid elements can also be used. In addition, the filler layer 53 or the filler layer 55 is also filled between the plurality of solar cells 54 without a gap.

The back sheet 56 protects the solar cell 54 and the filler layers 53 and 55 from the back side, and has a basic barrier of strength, weather resistance, heat resistance, and the like, and a gas barrier property against water vapor, oxygen gas, and the like. Known ones are used. The back sheet 56 has a multilayer structure in which a pair of synthetic resin layers are laminated on the front and rear surfaces of the gas barrier layer.

The adhesive sheet 1 for back surface protection of a solar cell module is affixed on the back surface of the back sheet 56 by the adhesive layer 3. The adhesive sheet 1 for back surface protection of a solar cell module is cut out in the shape which removed the part of the junction box 58, and is affixed.

Although it does not specifically limit as a manufacturing method of the said solar cell module 51, Generally, (1) Translucent board | substrate 52, the filler layer 53, the plurality of solar cell 54, and the filler layer 55 ) And laminating step of laminating back sheet 56 in this order, (2) laminating step of integrally molding them by vacuum heating lamination method or the like, which is integrated by vacuum suction and heat-compression, and (3) back sheet ( 56) The step of installing the junction box 58 on the back side, and (4) the adhesive sheet for solar back surface protection adhesive sheet 1 in a place other than the part where the junction box 58 on the back sheet 56 is installed. It has a process of laminating. In the method for manufacturing the solar cell module 51, (a) coating a hot melt adhesive, a solvent adhesive, a photocurable adhesive, or the like for the purpose of adhesion between the layers, and (b) facing each stack. The cotton may be subjected to ozone treatment, corona discharge treatment, low temperature plasma treatment, glow discharge treatment, oxidation treatment, undercoat treatment, primer coat treatment, anchor coat treatment and the like.

In addition, the adhesive sheet 1 for protecting the back surface of the solar cell module is a solar cell module (translucent substrate 52, a filler layer 53, a plurality of solar cell 54, and a filler layer 55 already used. And the back sheet 56 are laminated in this order, and a junction box 58 having both terminals of the wiring 57 for connecting each solar cell 54 to the back surface of the back sheet 56 is provided. It may be laminated on the back side of the), or may be laminated from the beginning of manufacture.

Since the said solar cell module 51 is equipped with the adhesive sheet 1 for back surface protection of a solar cell module as mentioned above, the surface of the back sheet 56 has a flaw, a crack, etc., for the reason that it has already used for a long time. Even when the physical defect 59 is generated, the pressure-sensitive adhesive layer 3 of the adhesive sheet 1 for protecting the back surface of the solar cell module fills this physical defect 59, thereby suppressing the expansion of the physical defect 59 and Moreover, since the permeation | transmission of water vapor etc. from this physical defect 59 part can be prevented, long life of a solar cell module can be promoted. In the case of a solar cell module in which no physical defects such as cracks are formed on the back surface of the back sheet 56, the adhesive sheet 1 is newly attached at regular or when a physical defect occurs, so that physical defects are always applied to the back surface. It is possible to maintain the state which it does not have, and the lifetime of a solar cell module becomes possible.

In addition, the adhesive sheet for solar cell module back surface protection of this invention, and the solar cell module using the same are not limited to the said embodiment. For example, the solar cell module laminated | stacks the solar cell module back surface protective adhesive sheets 11, 21, 31, 41 and other solar cell module back surface protective adhesive sheets other than the solar cell module back surface protective adhesive sheet 1, and others. You may.

Moreover, the barrier layer formed by vapor deposition can also be laminated | stacked in multiple layers through another layer. According to such an adhesive sheet for protecting the back surface of a solar cell module, the presence of a plurality of barrier layers not only increases the water vapor barrier property, but also the layers between the barrier layers cover the physical surface defects of the surface of the inner barrier layer and the outer barrier. As a result, the smoothness of the interface on which the layers are laminated is promoted, and the density of the outer barrier layer can be promoted. Therefore, according to this adhesive sheet, generation | occurrence | production of defects, such as a pinhole, a crystalline system, a crack, etc. to the barrier layer after the 2nd layer is reduced, and gas barrier property with respect to water vapor etc. improves. Moreover, as a layer provided between the barrier layers laminated | stacked by vapor deposition, the layer formed by said sol-gel method can also be used.

In addition, for example, the fine uneven | corrugated shape by embossing etc. is made to one outermost surface (most outer surface of the side in which the adhesive layer is not laminated | stacked with respect to the base material layer) of the adhesive sheet 1 for solar cell module back surface protection. You may form. As a result of the fine concavo-convex processing on the back surface, the surface area is enlarged, the heat dissipation is increased, and the temperature rise of the solar cell module can be suppressed, so that the increase in power generation efficiency and the long life of the solar cell module can be connected. have.

In addition, you may provide a barrier layer in the both surface side with respect to a base material layer. As this barrier layer, you may laminate | stack by vapor deposition of metals, such as aluminum and an inorganic oxide, and aluminum foil may be laminated | stacked. As the barrier layer is laminated on both surface sides of the substrate layer in this manner, the gas barrier property, physical durability, and the like of the pressure-sensitive adhesive sheet for protecting the solar cell module back surface can be further improved.

As mentioned above, the adhesive sheet for solar cell module back surface protection of this invention is used as an adhesive sheet which protects the back surface of a solar cell module for the purpose of extending the life of a solar cell module. In particular, it is suitably used as a protective adhesive sheet of the solar cell module of the outdoor attachment which can be used in the situation where secular deterioration is severe.

1, 11, 21, 31, 41 Adhesive sheet for protecting solar cell module back
2 base material layer 3 adhesive layer
4 Barrier Layer 5 Barrier Layer
6 Adhesive Layer 51 Solar Cell Module
52 Translucent Substrate 53 Filler Layer
54 Solar Cell 55 Filler Layer
56 Back Sheet for Solar Module 57 Terminals
58 Junction Box 59 Physical Defects

Claims (10)

A base material layer made of synthetic resin and an adhesive layer laminated on one surface side of this base material layer, and the average thickness of this adhesive layer is 0.01 mm or more and 1 mm or less, The adhesive sheet for solar cell module back surface protections characterized by the above-mentioned. The adhesive sheet for back surface protection of a solar cell module according to claim 1, wherein an acrylic pressure sensitive adhesive is used as the pressure sensitive adhesive constituting the pressure sensitive adhesive layer. The adhesive sheet for back surface protection of a solar cell module according to claim 1, wherein a butyl rubber-based pressure-sensitive adhesive is used as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer. The ultraviolet-ray curable adhesive is used as an adhesive which comprises the said adhesive layer, The adhesive sheet for solar cell module back surface protection of Claim 1 characterized by the above-mentioned. 2. The barrier layer according to claim 1, further comprising a barrier layer laminated on the other side of the base layer and / or between the base layer and the pressure-sensitive adhesive layer.
The barrier layer contains an inorganic substance, The adhesive sheet for solar cell module back surface protections characterized by the above-mentioned. The adhesive sheet for protecting a back surface of a solar cell module according to claim 5, wherein the inorganic material is an inorganic oxide. The adhesive sheet for back surface protection of a solar cell module according to claim 5, wherein the inorganic material is aluminum. The adhesive sheet for back surface protection of a solar cell module according to claim 5, wherein a plurality of barrier layers are laminated. The adhesive sheet for solar cell module back surface protection of Claim 1 in which one surface of the said adhesive layer is coat | covered with a release sheet. A solar cell module in which a transparent substrate, a filler layer, a solar cell as a photovoltaic element, a filler layer, a back sheet, and a pressure sensitive adhesive sheet for protecting the back surface of a solar cell module are laminated in this order on the surface side,
The adhesive sheet for solar cell module back surface protection of Claim 1 is affixed on the back surface of the said back sheet by the adhesive layer, The solar cell module characterized by the above-mentioned.

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