JP5570367B2 - Laminate - Google Patents

Description

  The present invention relates to a laminate. In particular, the present invention relates to a laminate suitably used for protecting a power generating element of a solar cell.

  In recent years, the global warming phenomenon has heightened awareness of the environment, and a new energy system that does not generate greenhouse gases such as carbon dioxide is attracting attention. Since the energy generated by solar cell power generation does not emit carbon dioxide and other gases that cause global warming, research and development has been conducted as clean energy, and has attracted attention as industrial energy. Representative examples of solar cells include those using single crystal and polycrystalline silicon cells (crystalline silicon cells), those using amorphous silicon, and compound semiconductors (thin film cells).

  Since solar cells are often used outdoors for a long period of time by being exposed to wind and rain, the power generation element is made into a module by laminating a glass plate, a protective sheet, etc., to prevent moisture from entering from the outside, It protects the power generation elements and prevents leakage. The member that protects the power generation element uses transparent glass or transparent resin on the light incident side in order to ensure light transmission necessary for power generation. The opposite member has a protective sheet (for example, an aluminum foil sheet, a polyvinyl fluoride resin (PVF) sheet, a polyethylene terephthalate (PET) sheet), a laminated sheet in which two or more of them are laminated (a barrier coat layer made of silica or the like). It can also be used instead of aluminum foil). The power generation element is sandwiched between resin sealing sheets, the outside is further covered with glass or a protective sheet, heat treatment is performed, the resin sealing sheet is melted, and the whole is integrally sealed (modularized).

  The resin-sealed sheet described above is required to have the following characteristics (1) to (3), for example. (1) Good adhesion to glass, power generation element and protective sheet, (2) Flow prevention (creep resistance) of power generation element due to melting of resin-sealed sheet at high temperature, (3 ) The resin-encapsulated sheet on the light-receiving side has transparency that does not hinder the incidence of sunlight. From this point of view, conventionally, a resin encapsulating sheet is made of an ethylene-vinyl acetate copolymer (hereinafter also abbreviated as EVA), a UV absorber, and a cup for improving adhesion to glass as a countermeasure against UV deterioration. Additives such as organic peroxides for ring agents and cross-linking are blended to form a film by calendar molding or T-die casting.

As a mode for producing a solar cell module with the resin sealing sheet as described above, glass / resin sealing sheet / power generation element such as crystalline silicon cell / resin sealing sheet / protective sheet are stacked in this order, and the glass surface is laminated. Using a dedicated solar cell vacuum laminator, the resin encapsulated sheet is melted and pasted through a preheating step and a pressing step above the melting temperature of the resin (temperature condition of 150 ° C in the case of EVA). There is a way. In this method, first, the resin of the resin sealing sheet is melted in the preheating process, and is in close contact with the member in contact with the melted resin in the pressing process and vacuum laminated. Solar cells are widely manufactured by such a method.
On the other hand, in order to raise the efficiency of the work of superimposing the members before modularization, those in which the resin sealing sheet and the light receiving surface member are integrated and those in which the resin sealing sheet and the protective sheet are integrated have been developed. It is coming.

Patent Document 1 discloses a back surface protection sheet for a solar cell module having a weather resistant resin film and an adhesive resin layer. This adhesive resin layer can also function as a resin sealing sheet.
Further, as a laminate in which the resin sealing sheet and the light receiving surface member are laminated and integrated, or a laminate in which the protective sheet and the resin sealing sheet are laminated and integrated, for example, Patent Document 2 discloses a transparent protective member. A solar cell cover material and sealing film in which an ethylene-vinyl acetate copolymer film is laminated and integrated is disclosed.

Japanese Patent Publication No. 4-33146 Japanese Patent No. 3978911

In the conventional general method, when modularization is performed, each solar cell member is stacked one layer at a time, and then thermocompression bonding is performed using a laminator. In such a laminating operation, it is difficult to accurately align the positions of the members, and the components are easily misaligned. Moreover, if sealing is performed in a state of being laminated in a shifted state, the cell may be broken or the gap filling property may be insufficient. Moreover, the resin sealing sheet | seat which used ethylene vinyl acetate acetate as the main raw material, and the protection sheet | seat which used polyester resin as the main raw material have the fault that it is very difficult to adhere | attach by the extrusion lamination method.
Further, it is desired that the module suppresses a gap between the power generation element and the resin sealing sheet, is excellent in adhesion between the resin sealing sheet and the protective sheet, and is excellent in weather resistance.
Further, from the viewpoint of manufacturing the module with high productivity, it is desired that the laminating apparatus is difficult to get dirty at the time of manufacturing the module (when laminating each member).

  The present invention has been made in view of the above circumstances, and has a gap filling property (a gap between the power generation element and the resin sealing sheet is suppressed during module manufacture), and an adhesive property (the resin sealing sheet and the protective sheet). It is possible to realize a module with excellent peel strength (after modularization) and weather resistance (appearance change is suppressed in the accelerated test), and productivity in the module manufacturing process. To provide a laminate that can realize a manufacturing method that is excellent in (can suppress displacement during manufacturing) and excellent in continuous operation (that is, the laminating apparatus is not easily soiled during vacuum lamination of module manufacturing). Objective.

The present inventors have found that a laminate obtained by laminating a resin-encapsulated sheet, an acrylic resin having a glass transition temperature (Tg) of −5 ° C. or lower, and a protective sheet in this order can solve the above-mentioned problems. Completed.
That is, the present invention is as follows.
[1]
The laminated body which laminated | stacked the resin sealing sheet (A), the resin layer (B) which consists of acrylic resin (x) whose glass transition temperature (Tg) is -5 degrees C or less, and the protection sheet (C) in this order.
[2]
The acrylic resin (x) is 0.2 to 1.2 parts by mass of a chain transfer agent and 0.2 to 5 parts by mass of a polyfunctional monomer with respect to 100 parts by mass of the ethylenically unsaturated monomer. The laminate according to [1], obtained by polymerizing a mixed monomer containing.
[3]
The laminate according to [1] or [2], wherein the resin layer (B) is formed by applying an emulsion containing the acrylic resin (x) and drying.
[4]
The laminate according to [3], wherein the emulsion is a white enamel paint further containing a white pigment.
[5]
The resin encapsulating sheet (A) is selected from the group consisting of an ethylene-vinyl acetate copolymer, an ethylene-aliphatic unsaturated carboxylic acid copolymer, an ethylene-aliphatic unsaturated carboxylic acid ester copolymer, and a polyolefin resin. The laminate according to any one of [1] to [4], comprising at least one selected resin.
[6]
The laminate according to any one of [1] to [5], wherein the resin encapsulating sheet (A) has a gel fraction of 0.1 to 65% by mass.
[7]
The laminate according to any one of [1] to [6], wherein the resin sealing sheet (A) has a crosslinked structure.
[8]
The laminate according to [7], wherein the crosslinked structure is formed by ionizing radiation irradiation.
[9]
The laminate according to any one of [1] to [8], wherein the resin sealing sheet (A) contains an adhesive resin (excluding a silane coupling agent).
[10]
The laminate according to any one of [1] to [9], wherein the protective sheet (C) contains a polyester resin or a fluorine resin.
[11]
The laminate according to any one of [1] to [10], wherein the water vapor permeability of the protective sheet (C) measured under conditions of 40 ° C. and 90% RH is 2.0 g / m ² / day or less. object.
[12]
The protective sheet (C) includes a vapor deposition layer and / or a water vapor barrier layer,
The vapor deposition layer is a layer containing at least one selected from the group consisting of alumina, silica, alumina-silica, inorganic particles, and inorganic oxides,
The laminate according to any one of [1] to [11], wherein the water vapor barrier layer is a layer containing at least one selected from the group consisting of a coating layer, an aluminum foil, and a PET film.
[13]
The laminate according to any one of [1] to [12], wherein the resin sealing sheet (A), the resin layer (B), and the protective sheet (C) are laminated by a dry lamination method.
[14]
A solar cell module using the laminate according to any one of [1] to [13] as a solar cell protective member.

  According to the present invention, it is possible to realize a module excellent in gap filling property, adhesiveness, and weather resistance, and in the module manufacturing process, it is excellent in productivity, and a manufacturing method excellent in continuous operability can be realized. A laminate can be provided.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the invention.
The laminate according to the present embodiment includes a resin sealing sheet (A) and a resin layer (B) containing an acrylic resin (x) having a glass transition temperature (Tg) of −5 ° C. or lower (hereinafter simply referred to as “resin layer”). (B) "), and the protective sheet (C) is included in this order. By laminating and integrating the resin sealing sheet and the protective sheet in advance, positioning when various components are overlaid in the laminate for module production becomes easy.
The details of the action are not detailed, but the resin layer made of an acrylic resin having a glass transition temperature (Tg) of −5 ° C. or lower moderately cushions the deformation of the resin encapsulating sheet, thereby filling the gap as a laminate. In addition to ensuring the properties, the stress at the interface of each layer generated in the weather resistance test can be appropriately dispersed to enable adhesion with weather resistance.
Furthermore, since the fluidity at the time of lamination which the resin layer which consists of acrylic resin whose glass transition temperature (Tg) is -5 degrees C or less is adjusted appropriately, it may flow too much at the time of lamination and may protrude from a laminate member. As a result, the continuous operability of the module manufacturing process can be improved.
Hereinafter, the items of [Resin encapsulating sheet (A)], [Resin layer containing acrylic resin (B)], [Protective sheet (C)], and [Manufacturing method of laminate] will be described below. In addition, [Method for manufacturing solar cell module] and [Use of laminate] using the laminate according to the present embodiment will also be described.

[Resin encapsulating sheet (A)]
As the resin-encapsulated sheet, a sheet that has good gap filling properties, excellent creep resistance and adhesion, and can protect the solar cell power generation element without causing deterioration of the resin over time is preferable. Since the resin sealing sheet (A) used in the present embodiment is installed on the back side of the power generation element as viewed from the light receiving surface, the transparency is not particularly limited, and may be white or other colors. In the present embodiment, a sheet formed using a known method may be used.
(Resin type)
The resin sealing sheet (A) used in the present embodiment is preferably a sheet in which a layer containing at least the following resin as a main component is provided on the side in contact with the object to be sealed.
The resin encapsulating sheet (A) used in the present embodiment is composed of an ethylene-vinyl acetate copolymer (EVA), an ethylene-aliphatic unsaturated carboxylic acid copolymer from the viewpoints of flexibility and adhesion to an adherend. It is preferable to include at least one resin selected from the group consisting of a polymer, an ethylene-aliphatic unsaturated carboxylic acid ester copolymer, a thermoplastic elastomer, and a polyolefin resin. Further, other thermoplastic elastomers may be used.
In the present embodiment, the “main component” means that the ratio of the specific component to the total amount of the specific component and the matrix component is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably. 90 mass% or more, meaning that it may be substantially 100 mass%.

The thermoplastic elastomer refers to a material that exhibits rubber elasticity at room temperature and has thermoplasticity, and is obtained by blending a copolymer rubber and a predetermined polymer at an arbitrary mass ratio. The copolymer rubber can exist in a state of uncrosslinked, partially crosslinked, totally crosslinked, etc. in the thermoplastic elastomer.
As the thermoplastic elastomer, for example, olefin-based, styrene-based, vinyl chloride-based, polyester-based, urethane-based, chlorinated ethylene polymer-based, polyamide-based, etc. can be applied. Etc. may be used. In particular, hydrogenated block copolymer elastomers, propylene copolymer elastomers, and ethylene copolymer elastomers that have good compatibility with crystalline polypropylene resins and good transparency are preferred. Hydrogenated block copolymers An elastomer and a propylene copolymer elastomer are more preferable.

  The hydrogenated block copolymer elastomer is preferably a hydrogenated block copolymer of vinyl aromatic hydrocarbon and conjugated diene. Examples of vinyl aromatic hydrocarbons include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, and 1,1-diphenyl. Examples thereof include ethylene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, and styrene is particularly preferable. These may be used alone or in combination of two or more. The conjugated diene is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3- Examples include butadiene, 1,3-pentadiene, and 1,3-hexadiene. These may be used alone or in combination of two or more.

  The above-mentioned ethylene-vinyl acetate copolymer, ethylene-aliphatic unsaturated carboxylic acid copolymer, and ethylene-aliphatic unsaturated carboxylic acid ester copolymer are ethylene monomer, vinyl acetate, and aliphatic unsaturated carboxylic acid. And a copolymer with at least one selected from the group consisting of aliphatic unsaturated carboxylic acid esters and the like.

  For the polymerization of the copolymer, a known method such as a high pressure method or a melting method can be applied, and a multisite catalyst or a single site catalyst may be used. In addition, the bonding shape at the time of polymerization may be any of random bond, block bond, etc., but from the viewpoint of obtaining good optical properties, ethylene-vinyl acetate copolymer polymerized by random bond using a high-pressure method, ethylene -An aliphatic unsaturated carboxylic acid copolymer and an ethylene-aliphatic unsaturated carboxylic acid ester copolymer are preferable.

  In the case where the ethylene-vinyl acetate copolymer (EVA) is a resin constituting the resin encapsulating sheet (A), from the viewpoint of obtaining good adhesiveness and flexibility, the ratio of vinyl acetate to the entire copolymer is 10 to 10%. 40 mass% is preferable, 13-35 mass% is more preferable, 15-30 mass% is further more preferable.

Specific examples of the ethylene-aliphatic unsaturated carboxylic acid copolymer and the ethylene-aliphatic unsaturated carboxylic acid ester copolymer are given below. For example, ethylene-acrylic acid copolymer (hereinafter also referred to as EAA), ethylene-methacrylic acid copolymer (hereinafter also referred to as EMAA), ethylene-acrylic acid ester (carbon such as methyl, ethyl, propyl, and butyl) Selected from alcohol components of 1 to 8.) Copolymer, ethylene-methacrylic acid ester (selected from components of alcohol having 1 to 8 carbon atoms such as methyl, ethyl, propyl, butyl, etc.) copolymer, etc. Is mentioned.
The content of various carboxylic acids or carboxylic acid ester groups in the copolymer is usually 3 to 35% by mass.
The material constituting the resin-encapsulated sheet (A) is appropriately selected from the above-mentioned two-component copolymers and multi-component copolymers of three or more components (for example, ethylene, aliphatic unsaturated carboxylic acid and the same ester). It may be a ternary or more selected copolymer).

  Examples of the polyolefin resin include polyethylene resins (ethylene homopolymers and other monomers and copolymers of ethylene monomers as main components), polypropylene resins (propylene homopolymers and other Copolymer of monomer and propylene monomer as main component), polybutene resin (butene homopolymer and copolymer of other monomer and butene monomer as main component), etc. Can be mentioned.

Examples of the polyethylene resin include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and linear ultra low density polyethylene (referred to as “VLDPE” and “ULDPE”).
Examples of the polyethylene resin include ethylene-α-olefin copolymers. The ethylene-α-olefin copolymer can be generally polymerized using a catalyst called a single site catalyst or a multisite catalyst. In particular, those polymerized with a single site catalyst are preferred. In addition, any one comonomer selected from ethylene comonomer, butene comonomer, hexene comonomer, and octene comonomer is preferable as the copolymer material.

The density of the polyethylene resin is preferably in the range of 0.860 to 0.920 g / cm ³ , more preferably 0.870 to 0.915 g / cm ³ from the viewpoint of obtaining good cushioning properties, and 0.870. -0.910 g / cm < ³ > is more preferable.

Examples of the polypropylene resin include copolymers of propylene and α-olefins such as ethylene, butene, hexene, and octene, and ternary copolymer weights of propylene, ethylene, and α-olefins such as butene, hexene, and octene. Examples include coalescence.
These copolymers may be block copolymers or random copolymers, and are preferably a random copolymer of propylene and ethylene, or a random ternary copolymer of propylene, ethylene and butene.

  The polypropylene resin exhibits functions such as increasing the hardness and waist of the resin encapsulating sheet and increasing heat resistance. Moreover, 50-90 mass% is preferable, and, as for content of the propylene in a polypropylene-type copolymer, it is more preferable that it is 60 mass% or more.

  When a polypropylene resin is used as a main component of the resin sealing sheet, a rubber component having a high concentration up to about 50% by mass may be uniformly and finely dispersed. A polypropylene-based copolymer is a ternary copolymer and has a propylene content of 60 to 80% by mass, an ethylene content of 10 to 30% by mass, and a butene content of 5 to 20% by mass. It is preferable because the property tends to be improved.

  The melt flow rate value (230 ° C., 2.16 kgf) measured according to JIS-K-7210 of polypropylene resin is preferably 0.3 to 15 g / 10 min, more preferably 0.5 to 12 g / 10 min. 0.8-10 g / 10 min is more preferable.

  Furthermore, since the polybutene resin is excellent in compatibility with the polypropylene resin in addition to the adjustment of the hardness and waist of the resin sealing sheet (A), it can be used in combination with the polypropylene resin. The polybutene resin is a crystalline butene-1 content of 70 mol% or more, and one or more of other monomers (ethylene, propylene, olefins having 5 to 8 carbon atoms). Those having a high molecular weight including a copolymer are preferably used. The MFR (190 ° C., 2.16 kg) of the polybutene resin is preferably 0.1 to 10 g / 10 min. Preferable polybutene-based resins include copolymers having a Vicat softening point of 40 to 100 ° C. The Vicat softening point is a value measured according to JIS K7206-1982.

(Crosslinking treatment)
The resin sealing sheet (A) used in the present embodiment is preferably crosslinked and has a crosslinked structure. When the resin sealing sheet (A) is subjected to a crosslinking treatment, when applied to a solar cell module, the creep resistance of the power generation cell tends to be excellent. The cross-linking treatment of the resin-encapsulated sheet (A) can be performed either before lamination for producing a laminate with the protective sheet (C), at the time of heating the vacuum lamination for producing the module, or in the curing process after modularization. is there. In particular, it is preferable that the resin-encapsulated sheet (A) is subjected to a crosslinking treatment before laminating the laminate with the protective sheet (C).

  The resin-encapsulated sheet (A) is preferably a thermoplastic elastomer from the viewpoint of the creep resistance of the cell after module production, and more preferably one that has been subjected to crosslinking treatment than one that has not been subjected to crosslinking treatment.

When the resin sealing sheet (A) is cross-linked before the laminate for producing the laminate with the protective sheet (C), the resin encapsulating sheet (A) at the time of laminating the laminate with the protective sheet (C) ) Tends to be suppressed.
Although this cause has not been fully elucidated, the following may be considered. Since the resin sealing sheet (A) is subjected to a crosslinking treatment, even if the resin sealing sheet (A) is heated at the time of laminating the laminate, the thermoplastic resin constituting the resin sealing sheet (A) The flow of the molecular chain is suppressed, and the deformation flow of the resin sealing sheet (A) is reduced. As a result, it is considered that the laminate operation for producing the laminate can be stably performed because the sheet adhesion to the roll of the laminator machine during the laminate production is reduced. In addition, operational troubles due to melt cutting of the sheet during lamination of the laminate are reduced.

In general, when the resin-encapsulated sheet (A) is subjected to a crosslinking treatment, the anchoring effect on the protective sheet (C) is reduced, and the adhesiveness is hindered. However, by interposing a resin layer (B) containing an acrylic resin having a glass transition point of −5 ° C. or lower, the adhesion between both sheets can be sufficiently improved.
When the resin encapsulating sheet is cross-linked before lamination, the resin encapsulating sheet is less deformed when laminating, and the resin adheres to the laminator during module lamination. It becomes difficult to do.

(Method of crosslinking treatment)
Examples of the crosslinking treatment include conventionally known methods such as irradiation with ionizing radiation and a method using an organic peroxide such as peroxide. Organic peroxides such as peroxide may decompose under high temperature conditions. If the crosslinking treatment is performed by ionizing radiation irradiation, it is not necessary to use an organic peroxide, and storage is facilitated. In addition, it is considered that there is little influence on the resin-encapsulated sheet even if a laminate method for producing a laminate using heat is used. For this reason, the crosslinking process by ionizing radiation irradiation is especially preferable. A resin that can be crosslinked by irradiation with ionizing radiation can be referred to as an “ionizing radiation crosslinking resin”.
Furthermore, other causes that are suitable for crosslinking treatment by irradiation with ionizing radiation have not been fully elucidated. It is generated and contributes to the adhesiveness of the laminate.

Further, when a crosslinking treatment with ionizing radiation is performed, a saponified olefin copolymer, an ethylene-vinyl acetate copolymer, an ethylene-aliphatic unsaturated carboxylic acid copolymer, an ethylene-aliphatic unsaturated carboxylic acid ester It is possible to prevent unreacted components such as organic acids and peroxides from remaining in the resin due to elimination of the side chain portion of the copolymer, etc., and the solar cell, conductive functional layer or wiring due to unreacted components There is a tendency to prevent adverse effects.
Furthermore, in the cross-linking treatment using ionizing radiation, the curing process for promoting the cross-linking of the resin encapsulating sheet, which is necessary in the cross-linking treatment using the organic peroxide, is not required in the laminating process of module production. It tends to be faster.

In the case of crosslinking by irradiation with ionizing radiation, a method of irradiating the resin encapsulating sheet (A) with ionizing radiation such as α-ray, β-ray, γ-ray, neutron beam, electron beam and the like can be used. The acceleration voltage of ionizing radiation such as an electron beam may be selected according to the thickness of the resin encapsulating sheet (A). Can be set to 300 kV or more.
The acceleration voltage of ionizing radiation such as an electron beam can be appropriately adjusted according to the resin layer subjected to the crosslinking treatment. The irradiation dose of ionizing radiation varies depending on the resin used, but is generally less than 3 kGy. The uniform crosslinked resin encapsulating sheet (A) tends not to be obtained. On the other hand, if the irradiation dose of ionizing radiation exceeds 500 kGy, the gel fraction of the resin-encapsulated sheet (A) becomes too large, and when used for solar cells, there is a risk that the unevenness step and the embeddability of gaps cannot be ensured. is there. It is preferable to appropriately adjust the acceleration voltage and irradiation dose of ionizing radiation in order to obtain a desired gel fraction. Crosslinking can be evaluated by measuring the gel fraction.

The ionizing radiation cross-linking resin is not particularly limited as long as it is a resin that is cross-linked by the above-mentioned ionizing radiation, but it is preferable that the flexibility and the adhesiveness with the adherend are good, from this viewpoint, For example, at least one selected from the group consisting of ethylene-vinyl acetate copolymer (EVA), ethylene-aliphatic unsaturated carboxylic acid copolymer, ethylene-aliphatic unsaturated carboxylic acid ester copolymer, and polyolefin resin. It is preferable to include a kind of resin.
Here, the ethylene-vinyl acetate copolymer (EVA), the ethylene-aliphatic unsaturated carboxylic acid copolymer, the ethylene-aliphatic unsaturated carboxylic acid ester copolymer, and the polyolefin resin are the same as those described above. Can be mentioned.
Further, in the case of crosslinking by irradiating with ionizing radiation, a resin having a polar group is preferably included because a resin having a polar group is more easily cross-linked than the case of using only a polyolefin resin.

In the case of performing a crosslinking treatment using an organic peroxide, as an organic peroxide, compatibility with a good ethylene-based copolymer is obtained, and from the viewpoint of having the half-life, for example, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl-4,4-bis (t-butylperoxy) Oxy) valerate, 2,2-bis (t-butylperoxy) butane and the like can be used.
When the resin-encapsulated sheet (A) is crosslinked using these organic peroxides, the crosslinking time can be relatively short, and the conventionally used half-life at 100 to 130 ° C. is 1 hour. The curing process can be shortened to about half compared to the case where the above organic peroxide is used.
0-10 mass% is preferable with respect to resin which comprises a resin layer, and, as for content of an organic peroxide, 0-5 mass% is more preferable.
Resin-encapsulated sheet containing organic peroxide is softened during module fabrication, and after the gap is filled, the decomposition and crosslinking of organic peroxide are promoted, so the resin gel fraction There is an advantage that the gap filling property is not hindered even when the size of the gap increases.

(Gel fraction)
In this Embodiment, 0.1-65 mass% is preferable, and the gel fraction of the resin sealing sheet (A) before lamination for laminate production or before lamination for module production is 0.1-60 mass%. Is more preferable. If the gel fraction is 0.1 to 65% by mass, problems (peeling, cell cracking, etc.) at the time of modularization due to the difference in shrinkage between the protective sheet (C) and the resin encapsulating sheet (A). It tends to be reduced. Furthermore, if it is 0.1-60 mass%, even when there exists a difference in shrinkage | contraction rate with a protection sheet (C) by the elasticity of the resin sealing sheet (A), a module can be produced more smoothly.
In order to achieve the gel fraction, in addition to the irradiation amount of ionizing radiation, the difference in the degree of crosslinking depending on the type of resin, the effect of crosslinking promotion or crosslinking inhibition by a chain transfer agent or the like may be utilized.

(Adhesion method)
The resin sealing sheet (A) used in the present embodiment is a sheet that is sealed by being brought into close contact with an object to be sealed in a heated and softened state in the formation of a solar cell module. At this time, there is no restriction | limiting in particular as a means for sticking each member, Well-known methods, such as a silane coupling agent and adhesive resin (except a silane coupling agent), can be used. Moreover, you may combine those methods.
In the case where an adhesive resin is used, the following advantages can be mentioned in storage when a laminate is used. That is, when an adhesive resin is used, there is an advantage that it is not necessary to use a silane coupling agent that is deactivated by heat or moisture, and the adhesiveness is maintained even under conditions of high temperature and high humidity. Further, when an adhesive resin is used, for the same reason, the adhesiveness with other members of the resin sealing sheet tends not to be lost at the time of laminating the laminate.
Furthermore, although not fully elucidated, another advantage is that the adhesive strength of the adhesive resin and the acrylic resin layer tends to increase.

Here, examples of the silane coupling agent include γ-chloropropylmethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-Ethoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (amino Examples thereof include those having an unsaturated group or an epoxy group such as ethyl) -γ-aminopropyltrimethoxysilane glycidoxypropyltriethoxysilane.
0-10 mass% is preferable with respect to resin which comprises the resin layer in a resin sealing sheet (A), and, as for content of a silane coupling agent, 0-5 mass% is more preferable.

When a silane coupling agent is used, an ethylene-vinyl acetate copolymer, an ethylene-aliphatic unsaturated carboxylic acid copolymer, and an ethylene-aliphatic unsaturated carboxylic acid ester copolymer to which the silane coupling agent is added And at least one resin selected from the group consisting of polyolefin resins.
It is preferable that the resin sealing sheet (A) used for this Embodiment contains adhesive resin (except a silane coupling agent).

  The case where adhesive resin is included in resin which comprises the resin sealing sheet (A) used for this Embodiment is demonstrated. The adhesive resin is not particularly limited, but from the viewpoint of obtaining good adhesiveness, an olefin-based copolymer having a hydroxyl group, a modified polyolefin terminally or graft-modified with an acidic functional group, glycidyl methacrylate (hereinafter referred to as “GMA”). It is preferable to include at least one resin selected from the group consisting of ethylene copolymers. When the adhesive resin is included, for example, when an ethylene copolymer including glycidyl methacrylate is included, stable adhesiveness can be exhibited because the reactivity of glycidyl methacrylate is high.

  Ethylene is suitable as the olefin constituting the olefin copolymer having a hydroxyl group. The hydroxyl group can be obtained, for example, by saponifying an acetic acid group of an ethylene-vinyl acetate copolymer or an ethylene-vinyl acetate-acrylic acid ester copolymer and replacing it with a hydroxyl group. Specific examples of the olefin-based copolymer having a hydroxyl group include an ethylene-vinyl acetate copolymer part or a completely saponified product, and an ethylene-vinyl acetate-acrylic acid ester copolymer part or a completely saponified product. .

  The ratio of the hydroxyl group in the olefin copolymer having a hydroxyl group is preferably 0.1% by mass to 10% by mass, and more preferably 0.1% by mass to 7% by mass in the resin layer. The ratio of the hydroxyl group is as follows: the original olefin polymer resin of the olefin polymer having the hydroxyl group, VA% (vinyl acetate copolymerization ratio by NMR measurement) of this resin, its saponification degree, It can be calculated from the blending ratio. When the ratio of the hydroxyl group in the olefin-based copolymer having a hydroxyl group is 0.1% by mass or more in the resin layer, good adhesiveness tends to be ensured. Good compatibility can be secured, and the finally obtained resin-sealed sheet tends to be prevented from becoming clouded.

The melting point of the olefin-based copolymer having a hydroxyl group is preferably 70 to 115 ° C., more preferably 73 to 115 ° C., from the viewpoint of ensuring good adhesiveness and sealing property (sealing property) to an object to be sealed. More preferably, it is 75-115 degreeC.
Here, the melting point of the olefin copolymer is obtained by using a differential scanning calorimeter, raising the temperature of about 5 mg of resin from 0 ° C. to 200 ° C. at a rate of 20 ° C./min, and melting and holding at 200 ° C. for 5 minutes. An endothermic peak associated with melting obtained when the temperature is lowered to −50 ° C. or lower at a rate of 20 ° C./min and then increased from 0 ° C. to 200 ° C. at 20 ° C./min.

The Vicat softening temperature of the olefin-based copolymer having a hydroxyl group is preferably 45 ° C. or higher, more preferably 47 ° C. or higher, from the viewpoint of ensuring good adhesiveness and sealing properties (sealing properties) to the object to be sealed. More preferably, it is 50 ° C. or higher.
Here, the Vicat softening temperature is a value measured according to JIS K7206-1982.

  When the olefin copolymer having a hydroxyl group is a saponified ethylene-vinyl acetate copolymer, the content of vinyl acetate in the ethylene-vinyl acetate copolymer before saponification is good optical properties and adhesiveness. And from a viewpoint of obtaining a softness | flexibility, 10-40 mass% is preferable with respect to the whole copolymer, 13-35 mass% is more preferable, 15-30 mass% is more preferable.

Next, a saponification method will be described. For example, a method of saponifying ethylene-vinyl acetate copolymer pellets or powder in a lower alcohol such as methanol using an alkali catalyst, or using an ethylene-vinyl acetate copolymer in advance using a solvent such as toluene, xylene or hexane. Examples include a method of dissolving a coalescence and then saponifying with a small amount of alcohol and an alkali catalyst. In addition, a method of graft polymerization of a monomer containing a functional group other than a hydroxyl group on a saponified copolymer may be mentioned.
Since the saponified ethylene-vinyl acetate copolymer has a hydroxyl group in the side chain, its adhesion is improved compared to the ethylene-vinyl acetate copolymer, and plastics such as glass, acrylic and polycarbonate resins. It is useful as an adhesive for metals, fibers and the like. Moreover, transparency and adhesiveness can be controlled by adjusting the amount of hydroxyl groups (degree of saponification).

Modified polyolefins that are terminally or graft-modified with acidic functional groups are, for example, polyethylene resins and polypropylene resins that are terminally or grafted with compounds having polar groups such as maleic anhydride, nitro groups, hydroxyl groups, and carboxy groups. Denatured ones are mentioned. Among these, from the viewpoint of the stability of the polar group, a maleic acid-modified polyolefin that is terminally or graft-modified with maleic anhydride is preferable.
Here, as the polyethylene-based resin and the polypropylene-based resin, the same resins as those mentioned for the polyolefin resin described later can be used.

  The ethylene copolymer containing glycidyl methacrylate refers to an ethylene copolymer and an ethylene terpolymer with glycidyl methacrylate having an epoxy group as a reaction site. For example, ethylene-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate-vinyl acetate copolymer And an ethylene-glycidyl methacrylate-methyl acrylate copolymer. Since the above compound has high reactivity of glycidyl methacrylate, it can exhibit stable adhesiveness.

  When the adhesive resin is used, the resin-encapsulated sheet (A) may be produced using the above-described adhesive resin, for example, one type of saponified ethylene-vinyl acetate copolymer. From the viewpoint of ensuring the adhesion and handling properties of the adherend, the resin-encapsulated sheet (A) includes an adhesive resin, an ethylene-vinyl acetate copolymer, an ethylene-aliphatic unsaturated carboxylic acid copolymer, It is preferably a sheet formed by mixing and molding at least one resin selected from the group consisting of an ethylene-aliphatic unsaturated carboxylic acid ester copolymer and a polyolefin resin. In addition, when the above-mentioned ionizing radiation is used for crosslinking, a resin having a polar group is more easily crosslinked than the case of using only a polyolefin resin.

  When the resin layer constituting the resin sealing sheet (A) contains a saponified ethylene-vinyl acetate copolymer as an adhesive resin, the degree of saponification and the content can be adjusted as appropriate. Adhesiveness with a stationary object can be controlled. From the viewpoint of adhesiveness and optical properties, the content of the saponified product is preferably 3 to 100% by mass, and 3 to 60% by mass, when the resin layer constituting the resin encapsulating sheet (A) is 100% by mass. More preferably, 3-55 mass% is further more preferable, and 5-50 mass% is still more preferable.

(Multilayer structure)
The resin sealing sheet (A) used in the present embodiment may have either a single layer structure or a multilayer structure.
When the resin sealing sheet (A) used in the present embodiment has a multilayer structure, it has a multilayer structure of at least two layers. It is preferable that it is a resin layer containing these. When an ionizing radiation crosslinkable resin is contained, it is considered that a functional group is formed on the surface of the resin encapsulating sheet during the ionizing radiation crosslinking treatment. Furthermore, there is a possibility that this functional group contributes to adhesion with the acrylic resin at the time of laminating the laminate.

When it is a multilayer, it is preferable that the resin layer containing the adhesive resin mentioned above is formed as a layer (surface layer) which contacts a to-be-sealed thing.
The layer ratio of the surface layer in contact with the object to be sealed preferably has a thickness of at least 5% or more with respect to the total thickness of the resin sealing sheet from the viewpoint of ensuring good adhesiveness. When the thickness is 5% or more, the same adhesiveness as in the case of the single layer described above can be obtained.

  In the resin-encapsulated sheet (A), for example, a resin having a polar group such as a saponified olefin copolymer, an ethylene monomer and vinyl acetate, an aliphatic unsaturated carboxylic acid, or an aliphatic unsaturated carboxylic acid ester is used as a surface layer. , Linear low density polyethylene (LLDPE), linear ultra-low density polyethylene (called "VLDPE", "ULDPE") resin, if the middle layer, acceleration voltage sufficient to penetrate all layers Even so, the gel fraction of the surface layer is high, and the gel fraction of the middle layer can be low.

  As content of adhesive resin in the resin layer which comprises a resin sealing sheet (A), Preferably it is 3-100 mass%, 3-60 mass% is more preferable, 3-55 mass% is further Preferably, 5 to 50% by mass is even more preferable. The content of the ionizing radiation-crosslinking resin in the resin layer constituting the resin sealing sheet (A) is preferably 0 to 97% by mass, more preferably 40 to 97% by mass, and more preferably 45 to 97% by mass. % Is more preferable, and 50 to 95% by mass is even more preferable.

Resin materials, mixtures, and additives can be selected for the purpose of imparting other functions to other layers other than the surface layer. For example, a layer containing a thermoplastic resin may be provided for the purpose of newly imparting cushioning properties.
Examples of the thermoplastic resin include olefin-based, styrene-based, vinyl chloride-based, polyester-based, urethane-based, chlorine-based ethylene polymer-based, polyamide-based, etc., and those having biodegradability and those derived from plant-derived materials included. In particular, a hydrogenated block copolymer resin, a propylene copolymer resin, and an ethylene copolymer resin, which have good compatibility with a crystalline polypropylene resin and good transparency, are preferred, a hydrogenated block copolymer resin and A propylene-based copolymer resin is more preferable.

  As the hydrogenated block copolymer resin, a hydrogenated product of a block copolymer of vinyl aromatic hydrocarbon and conjugated diene is preferable. Examples of vinyl aromatic hydrocarbons include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, and 1,1-diphenyl. Examples thereof include ethylene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, and styrene is particularly preferable. These may be used alone or in combination of two or more. The conjugated diene is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3- Examples include butadiene, 1,3-pentadiene, and 1,3-hexadiene. These may be used alone or in combination of two or more.

As the propylene-based copolymer resin, a copolymer obtained from propylene and ethylene or an α-olefin having 4 to 20 carbon atoms is preferable. The content of the ethylene or α-olefin having 4 to 20 carbon atoms is preferably 6 to 30% by mass. Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-pentene and 1-decene. 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosane and the like.
The propylene-based copolymer resin may be polymerized using a multi-site catalyst, a single-site catalyst, or any other catalyst. Further, a propylene-based copolymer in which the crystal / amorphous structure (morphology) of the polymer is controlled in nano order can be used. The ethylene copolymer resin may be polymerized with any of a multisite catalyst, a single site catalyst, and other catalysts. Further, an ethylene copolymer in which the crystal / amorphous structure (morphology) of the polymer is controlled in nano order can be used.

As a material for a layer that does not come into contact with the object to be sealed, when a polyethylene resin is used, the density is preferably 0.860 to 0.920 g / cm ³ from the viewpoint of obtaining an appropriate cushioning property, and 0.870 to 0. .915 g / cm ³ is more preferable, and 0.870 to 0.910 g / cm ³ is more preferable.

Next, the viewpoint of workability of the resin sealing sheet (A) will be examined. From the viewpoint of ensuring good processability, the MFR (190 ° C., 2.16 kg) of the resin constituting the surface layer and other layers of the resin-encapsulated sheet (A) is preferably 0.5 to 30 g / 10 min. 0.8 to 30 g / 10 min is more preferable, and 1.0 to 25 g / 10 min is more preferable.
In the case of a multilayer structure of two or more layers, the MFR of the resin constituting the middle layer and the lower layer adjacent to the surface layer is preferably lower than the MFR of the surface layer from the viewpoint of processing the resin sealing sheet (A).
The resin sealing sheet (A) used in the present embodiment has various additives such as an antifogging agent, a plasticizer, an antioxidant, a surfactant, a colorant, and an ultraviolet absorber as long as the characteristics are not impaired. Further, an antistatic agent, a crystal nucleating agent, a lubricant, an antiblocking agent, an inorganic filler, a crosslinking regulator, and the like may be added.

(Method for producing resin-encapsulated sheet (A))
Although there is no restriction | limiting in particular as a manufacturing method of a resin sealing sheet (A), For example, the following methods are mentioned. First, the resin is melted by an extruder, the molten resin is extruded from a die, and rapidly cooled and solidified to obtain an original fabric. As the extruder, a T die, an annular die or the like is used. When the resin sealing sheet (A) has a multilayer structure, an annular die is preferable.
The surface of the original fabric may be embossed according to the form of the final resin sealing sheet (A). For example, when embossing treatment is performed on both sides, between the two heated embossing rolls, when performing single-sided embossing processing, the original fabric is passed between embossing rolls heated only on one side. Embossing treatment can be performed.
When the resin sealing sheet (A) has a multilayer structure, a multilayer T die method and a multilayer annular die method are suitable. In addition, a multilayer structure may be formed by a known laminating method.

  The crosslinking treatment for the resin layer constituting the resin encapsulating sheet (A), that is, heat treatment by ionizing radiation irradiation treatment or use of organic peroxide, is performed as a pre-process or post-process of embossing treatment depending on each case. Select whether to do it.

The resin sealing sheet (A) used in the present embodiment preferably has a thickness of 50 to 1500 μm, more preferably 100 to 1000 μm, and even more preferably 150 to 800 μm. The thickness is preferably 50 μm or more from the viewpoint of durability and strength, and is preferably 1500 μm or less from the viewpoint of productivity and adhesion. Moreover, when the laminated body using this resin sealing sheet (A) is used for a silicon crystal solar cell and the thickness of the resin sealing sheet (A) of the laminate is 50 to 300 μm, the glass surface side It is preferable to use a sheet having a thickness of 300 to 800 μm as the resin sealing sheet.
The resin sealing sheet (A) used in the present embodiment is sealed using the softened state of the resin layer. The softened state of the resin can be created by directly applying thermal energy or by applying inherent vibration to the resin to generate heat. As a method of applying energy to the resin, a known method such as indirect heat such as radiant heat or vibrational heat generation such as ultrasonic waves can be applied in addition to a method of directly applying heat.

[Resin layer (B) made of acrylic resin (x)]
The resin layer (B) made of the acrylic resin (x) refers to a layer made of a resin composition containing an acrylic resin (preferably containing it as a main component).
The acrylic resin (x) is a homopolymer of at least one (meth) acrylate monomer, or a (meth) acrylate monomer and another monomer copolymerizable therewith. (Hereinafter, acrylic acid and methacrylic acid may be simply referred to as (meth) acrylic acid). Examples of other monomers copolymerizable with the (meth) acrylic acid ester monomer include other (meth) acrylic acid ester monomers, methacrylic acid monomers, acrylic acid monomers, and aromaticity. Examples thereof include vinyl monomers and other ethylenically unsaturated monomers.

  Although the said resin layer (B) is obtained using an acrylic resin, an acrylic emulsion, etc., it is not specifically limited to these. The acrylic resin refers to a dry powder containing an acrylic resin alone or a resin composition containing the acrylic resin. The acrylic emulsion means an emulsion containing an acrylic resin (x), and refers to an aqueous dispersion (milky product) of a resin obtained by emulsion polymerization of the above monomer in an aqueous system.

  The resin layer (B) is preferably manufactured from an acrylic emulsion from the viewpoint that the film thickness can be easily controlled. When the film thickness is more uniform, the protective sheet (C) and the resin sealing sheet (A) can be bonded uniformly during the production of the laminate. It is considered that the heat and pressure of the vacuum laminator are evenly transmitted, and it is possible to produce a good module in which gaps are filled without resin unevenness.

  The glass transition temperature (hereinafter also referred to as “Tg”) of the acrylic resin (x) is −5 ° C. or less from the viewpoint of initial adhesiveness. When the Tg of the acrylic resin (x) is −5 ° C. or lower, the adhesiveness between the resins and the initial adhesive strength are excellent. The Tg of the acrylic resin (x) is preferably −40 ° C. or higher and −10 ° C. or lower, and more preferably −35 ° C. or higher and −20 ° C. or lower.

  It is preferable that a resin layer (B) is manufactured from the below-mentioned silicone modified acrylic resin. The resin layer (B) produced in this way is excellent in weather resistance. The silicone-modified acrylic resin refers to a resin or a resin composition in which a siloxane bond and an acrylic resin coexist, such as a copolymer of a silicone modifier (siloxane compound) and an ethylenically unsaturated monomer, one of which Examples thereof include an acrylic resin having a silicone modifier bonded to the part, and a mixture of a silicone resin and an acrylic resin. Silicone resin refers to a polymer compound having a siloxane bond.

(Acrylic emulsion)
Ethylenically unsaturated monomers include (meth) acrylic acid alkyl ester monomers, ethylenically unsaturated carboxylic acid monomers, aromatic vinyl monomers, vinyl cyanide monomers, (meth) acrylamide single amount Carboxylic acid vinyl ester monomer, amino group-containing ethylenic monomer, vinyl halide, sulfonic acid group-containing monomer, phosphate group-containing monomer, polyfunctional monomer, other vinyl monomers A body etc. can be used conveniently.

  Examples of the (meth) acrylic acid alkyl ester monomer include (meth) acrylic acid alkyl esters having 1 to 18 carbon atoms in the alkyl moiety, and (poly) oxyethylene mono (meta) having 1 to 100 ethylene oxide units. ) Acrylate, (poly) oxypropylene mono (meth) acrylate, (meth) acrylic acid hydroxyalkyl ester having 1 to 18 carbon atoms in the alkyl portion, and (poly) oxyethylene dialkylene having 1 to 100 ethylene oxide units Examples include (meth) acrylate.

  Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and (meth) acrylic acid t. -Butyl, (meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid dodecyl, (meth) acrylic acid cycloalkyl ester and the like.

  Examples of the (meth) acrylic acid alkyl ester include methyl methacrylate, n-butyl methacrylate, butyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl (meth) acrylate, 2-hydroxycyclohexyl (meth) acrylate, ( Methyl cyclohexyl acrylate and 2,3-cyclohexene oxide (meth) acrylate are preferred.

  Specific examples of the (poly) oxyethylene mono (meth) acrylate include ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, diethylene glycol methoxy (meth) acrylate, ( Examples include tetraethylene glycol (meth) acrylate and tetraethylene glycol methoxy (meth) acrylate.

  Specific examples of the (poly) oxypropylene mono (meth) acrylate include propylene glycol (meth) acrylate, propylene glycol methoxy (meth) acrylate, dipropylene glycol (meth) acrylate, dimethoxy meth (meth) acrylate. Examples include propylene glycol, tetrapropylene glycol (meth) acrylate, and tetrapropylene glycol methoxy (meth) acrylate.

Specific examples of the (meth) acrylic acid hydroxyalkyl ester include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.
Specific examples of the (poly) oxyethylene di (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and di (meth) acrylic acid. Examples include tetraethylene glycol. In addition, since it acts also as a catalyst which accelerates | stimulates the hydrolysis reaction and condensation reaction of a silicone modifier when manufacturing a silicone modified acrylic emulsion, it is preferable to contain at least 1 sort (s) chosen from these groups.

  In the present embodiment, among (meth) acrylic acid alkyl ester monomers, the resin layer (B) having excellent durability can further include a (meth) acrylic acid alkyl ester monomer having a cycloalkyl group. This is preferable because it can be performed. A part of hydrogen atoms of the cycloalkyl group may be substituted with an alkyl group having 1 to 6 carbon atoms or a hydroxyl group, and an epoxy group may be present in a cyclic form. Examples of the (meth) acrylic acid alkyl ester monomer having a cycloalkyl group include (meth) acrylic acid cycloalkyl ester monomers. Examples of the (meth) acrylic acid cycloalkyl ester include esters of a cycloalkyl group having 5 to 12 carbon atoms. Specific examples of the (meth) acrylic acid alkyl ester monomer having a cycloalkyl group include compounds represented by the following formula (4).

(Where
R ⁶ is a hydrogen atom or a methyl group,
R ⁷ is a cyclopentyl group, a cyclohexyl group or a cyclododecyl group, and these cycloalkyl groups may have an alkyl group having 1 to 6 carbon atoms, a hydroxyl group or an epoxy group as a substituent. )

  Specific examples of the compound represented by the formula (4) include cyclohexyl (meth) acrylate, 2-hydroxycyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, and 2,3 cyclohexene (meth) acrylate. An oxide etc. can be mentioned. Among them, cyclohexyl methacrylate is preferable.

The content ratio of the (meth) acrylic acid alkyl ester monomer having the cycloalkyl group is preferably 5% by mass or more in the total mass of the (meth) acrylic acid alkyl ester monomer. It is more preferably 5% by mass to 99% by mass, and further preferably 5% by mass to 80% by mass.
One (meth) acrylic acid alkyl ester monomer having a cycloalkyl group may be used, or a mixture of two or more thereof may be used.
By containing 5% by mass or more of the (meth) acrylic acid alkyl ester monomer having a cycloalkyl group with respect to the total mass of the (meth) acrylic acid alkyl ester monomer in the ethylenically unsaturated monomer, It can be set as the resin layer (B) excellent in durability, and the film forming property of an acrylic emulsion becomes excellent by containing 99 mass% or less.

Examples of the ethylenically unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, crotonic acid, butenetricarboxylic acid, monoethyl maleate, monomethyl maleate, monoethyl itaconate, and monomethyl itaconate. These can be used alone or in combination of two or more.
Examples of the aromatic vinyl monomer include aromatic vinyl monomers other than ethyl vinyl benzene. For example, styrene, α-methyl styrene, vinyl toluene, p-methyl styrene, o-methyl styrene, m-methyl styrene, hydroxymethyl styrene, vinyl xylene, bromostyrene, vinyl benzyl chloride, pt-butyl styrene, chlorostyrene, Examples thereof include alkyl styrene and the like, and these can be used alone or in combination of two or more.
Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile and the like, and these can be used alone or in combination of two or more. In addition, since it acts also as a catalyst which accelerates | stimulates the hydrolysis reaction and condensation reaction of a silicone modifier when manufacturing a silicone modified acrylic emulsion, it is preferable to contain at least 1 sort (s) chosen from these groups.

Examples of the (meth) acrylamide monomer include N-monoalkyl (meth) acrylamides such as (meth) acrylamide, N-methylol (meth) acrylamide and N-methyl (meth) acrylamide, and N, N-dimethyl (meth). N, N dialkyl (meth) acrylamide such as acrylamide, glycidylmethacrylamide, N-alkoxy (meth) acrylamide, 2-acrylamido-2-methylpropane sulfonic acid and the like can be mentioned. These can be used in combination.
As the carboxylic acid vinyl ester, for example, vinyl acetate can be used.
Examples of the amino group-containing ethylenic monomer include aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, 2-vinylpyridine, and the like. It can be used in combination of more than one species.
Examples of vinyl halides include vinyl chloride and vinylidene chloride, and these can be used alone or in combination of two or more.

Examples of the sulfonic acid group-containing monomer include styrene sulfonate, 2- (meth) acryloyloxyethyl sulfonic acid, and (meth) allyl sulfonate. These may be used alone or in two types. These can be used in combination.
Examples of phosphate group-containing monomers include ethylene phosphate (meth) acrylate, propylene phosphate (meth) acrylate, and 2- (meth) acryloyloxyethyl acid phosphate. These can be used alone or in combination of two or more.

Examples of the polyfunctional monomer include a vinyl monomer having two or more radical polymerizable double bonds, a crosslinkable functional group-containing vinyl monomer, and a crosslinkable functional group-containing silane coupling agent. Can be mentioned.
Here, as the vinyl monomer having two or more radical polymerizable double bonds, for example, divinylbenzene, trivinylbenzene, hexatriene, divinyl ether, divinylsulfonic acid, diallyl phthalate, diallylcarbyl Nord, triallyl isocyanurate, polyfunctional (meth) acrylate and the like.
Examples of the polyfunctional (meth) acrylate include polyoxyethylene di (meth) acrylate, polyoxypropylene di (meth) acrylate, neopentyl glycol di (meth) acrylate, butanediol di (meth) acrylate, and tetramethylol. Methanetetra (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, tetramethylolethanetri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate Ethylene glycol di (meth) acrylate, 1-3-butylene glycol di (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, 1,5-pentadi -Ludi (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol (Meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate -Trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, allyl (meth) acrylate 2,2-bis [4-((meth) acryloxyethoxy) phenyl] propane, 2,2-bis [4-((meth) acryloxy-diethoxy) phenyl] propaprop , 2,2-bis [4 - ((meth) acryloxy polyethoxy) phenyl] propane, bis (4-acryloxy polyethoxy phenyl) propane.

  Examples of the crosslinkable functional group-containing vinyl monomer include an epoxy group-containing monomer (for example, glycidyl (meth) acrylate, allyl glycidyl ether, methyl glycidyl (meth) acrylate), and a methylol group-containing monomer (for example, N- Methylol (meth) acrylamide, dimethylol (meth) acrylamide), alkoxymethyl group-containing monomer (for example, N-methoxymethylacrylamide, N-butoxymethyl (meth) acrylamide, N-butoxymethyl methacrylamide, etc.), hydroxyl group-containing monomer Examples include a polymer.

Examples of the crosslinkable functional group-containing silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, tris-2-methoxyethoxyvinylsilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyl. Examples include methyldimethoxysilane.
Among these, glycidyl (meth) acrylate, trimethylolpropane tri (tri) acrylate, and pentaerythritol tetra (meth) acrylate are preferable from the viewpoint of improving weather resistance.

The amount of these polyfunctional monomers used is 0 with respect to 100 parts by mass of the ethylenically unsaturated monomer from the viewpoint of exhibiting adhesiveness after lamination and adhesiveness during wet heat as an appropriate crosslinking density. From the viewpoint of exhibiting initial adhesiveness as an appropriate molecular weight, it is preferably 5.0 parts by mass or less.
Examples of other vinyl monomers include vinyl acetate, vinyl propionate, vinyl versatate, vinyl pyrrolidone, and methyl vinyl ketone.

Examples of the method for producing the acrylic emulsion used in the present embodiment include polymerization methods such as emulsion polymerization, suspension polymerization, bulk polymerization, and miniemulsion polymerization, but are not particularly limited. As a method for stably producing an emulsion having an average particle size of about 10 nm to 1 μm and excellent dispersion stability, emulsion polymerization is preferred.
The emulsion polymerization is preferably carried out in an aqueous medium by radical polymerization of an ethylenically unsaturated monomer which is a radical polymerizable monomer. When obtaining a silicone-modified acrylic emulsion, in addition to the emulsion polymerization, a silicone-modified It is preferable that emulsion polymerization by hydrolysis / condensation reaction of the agent is simultaneously performed in an aqueous medium.

  As the aqueous medium, water is mainly used, but a medium in which a water-soluble solvent such as a lower alcohol having 1 to 3 carbon atoms or acetone is added to water can also be used. In this case, it is preferable to add so that the amount of the solvent other than water is 20% by mass or less in the pre-emulsified liquid before the start of polymerization. By setting the amount of the solvent other than water to 20% by mass or less, the emulsified state of the pre-emulsion liquid is not destroyed and emulsion polymerization proceeds stably. More preferably, emulsion polymerization is performed using only water as a solvent.

  In the present embodiment, when obtaining the silicone-modified acrylic emulsion, the pH of the pre-emulsion liquid composed of the ethylenically unsaturated monomer and the emulsifier before the emulsion polymerization is not particularly limited, but the pH is 4.0 or less. It is preferable that By carrying out the emulsion polymerization at a pH of 4.0 or less, it is possible to suppress the condensation reaction of the silicone modifier from occurring rapidly and the condensation reaction from proceeding after the emulsion polymerization. From the viewpoint of storage stability as a product, the pH of the reaction system is preferably 4.0 or less, and more preferably from 1.5 to 3.0.

  Moreover, in this Embodiment, there is no restriction | limiting in particular in the introduction method of the radical initiator at the time of performing emulsion polymerization. A persulfate or the like may be introduced into the reaction system in advance as a radical initiator. Alternatively, a pre-emulsion liquid composed of at least one ethylenically unsaturated monomer, an emulsifier and a radical initiator may be directly added to the reaction system sequentially. In addition to the pre-emulsified liquid, it can also be sequentially introduced into the reaction system by an aqueous solution system or the like.

In the present embodiment, in the radical polymerization for producing the silicone-modified acrylic emulsion, the silicone modifier may be added before the emulsion polymerization, during the emulsion polymerization, or after the emulsion polymerization. Good. More preferably, it is performed during emulsion polymerization. In the emulsion polymerization, it is particularly preferable that the emulsion polymerization by hydrolysis / condensation reaction of the silicone modifier is simultaneously with the start of emulsion polymerization by radical polymerization of the ethylenically unsaturated monomer.
Furthermore, a silicone resin obtained by hydrolysis / condensation reaction of a silicone modifier may be blended with an acrylic emulsion containing an acrylic resin.

The silicone modifier used in the present embodiment is a silane compound (1), a silane compound (2), a silane compound (3) and a cyclic silane represented by the following formulas (1), (2) and (3), respectively. A combination of two or more of these may be used, including at least one selected from compounds.
In the present embodiment, a silane compound (2) and a silane compound are used to maintain the weather resistance required for a module using a laminate, for example, a solar cell module using the laminate as a solar cell protective member. A combination with (3) is preferred.

(Where
R ¹ is a phenyl group or a cyclohexyl group;
R ² is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 6 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, an alkyl acrylate group having 1 to 10 carbon atoms, or carbon. An alkyl methacrylate group of 1 to 10,
R ³ is independently selected from an alkoxy group having 1 to 8 carbon atoms, an acetoxy group or a hydroxyl group;
m is 0 or 1. )

(Where
R ⁴ is independently selected from an alkoxy group having 1 to 8 carbon atoms, an acetoxy group, or a hydroxyl group. )

(Where
R ⁵ is independently selected from an alkoxy group having 1 to 8 carbon atoms, an acetoxy group or a hydroxyl group. )

  In the present embodiment, it is preferable to include at least one silane compound (1) as the silicone modifier because the coexistence of the silicone resin and the acrylic resin becomes smooth after polymerization. Moreover, it is preferable to contain at least one silane compound (2) as a silicone modifier in order to impart a crosslinking density of the silicone structure. Furthermore, the inclusion of at least one silane compound (3) and / or a cyclic silane compound as a silicone modifier reduces the crosslink density of the silicone polymer formed by the silicone modifier, thereby applying a silicone-modified acrylic emulsion. It is preferable because flexibility can be imparted when the film is formed.

Specific examples of the silane compound (1) used in the present embodiment include phenyltrimethoxysilane, diphenyldimethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, phenylmethyldimethoxysilane, cyclohexyltrimethoxysilane, and dicyclohexyldimethoxy. Examples thereof include silane, cyclohexyl triethoxysilane, and dicyclohexyldiethoxysilane. One kind of these compounds may be used, or two or more kinds thereof may be used.
As the silane compound (1), phenyltrimethoxysilane is preferable.
Specific examples of the silane compound (2) used in the present embodiment include methyltrimethoxysilane and methyltriethoxysilane. One of these compounds may be used, or two or more of these may be used.
As the silane compound (2), methyltrimethoxysilane is preferable.

Specific examples of the silane compound (3) used in the present embodiment include dimethyldimethoxysilane and dimethyldiethoxysilane. One of these compounds may be used, or two or more of these may be used.
As the silane compound (3), dimethyldimethoxysilane is preferable.
Specific examples of the cyclic silane compound used in this embodiment include octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, hexamethylcyclotrisiloxane, decamethylcyclopentasiloxane, and tetramethyltetravinylcyclotetrasiloxane. It is done. One of these compounds may be used, or two or more of these may be used.

  In addition to the silicone modifier selected from the silane compound (1), silane compound (2), silane compound (3) and cyclic silane compound, the silicone modifier is isobutyltrimethoxysilane, vinyltriethoxysilane, γ-acryloxy. Propyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-glycidoxypropyldimethoxymethylsilane , Γ-glycidoxypropyltriethoxysilane, tetramethoxysilane, tetraethoxysilane and the like.

  Further, an emulsion may be prepared from an ethylenically unsaturated monomer and an emulsifier with or without a silicone modifier, and the silicone emulsion may be blended later. Examples of silicone emulsions to be blended later include phenyl, linear alkyl, hydrogen, amino, epoxy, mercapto silicone emulsions and silicone resin emulsions in addition to dimethyl silicone emulsions.

When a resin layer obtained using a silicone-modified acrylic emulsion is used as the resin layer (B) used in the present embodiment, the silicone modifier is hydrolyzed / condensed to form an acrylic resin (acrylic emulsion particles). Since the silicone resin (siloxane bond) is present, extremely excellent weather resistance is achieved.
The presence of the condensate of the silicone modifier can be confirmed by ²⁹ Si-NMR ( ²⁹ Si nuclear magnetic resonance spectrum) or ¹ H-NMR (proton nuclear magnetic resonance spectrum). In ¹ H-NMR (proton nuclear magnetic resonance spectrum), tetramethylsilane is used as an internal standard, but in ²⁹ Si-NMR ( ²⁹ Si nuclear magnetic resonance spectrum), an internal standard is not used and silicon rubber is used. The signal is measured to be −22 ppm, or the measured value of a solution sample in which tetramethylsilane is dissolved in chloroform is set to 0 ppm and used as an external standard.

For example, the condensate of the silane compound (1) can be identified because the ²⁹ Si-NMR chemical shift shows a peak at −35 to −90 ppm. The condensate of the silane compound (2) can be identified because the chemical shift of ²⁹ Si-NMR shows a peak at -40 to -80 ppm. Furthermore, the condensate of the silane compound (3) can be identified because the chemical shift of ²⁹ Si-NMR shows a peak at -16 to -26 ppm. Moreover, the condensate of a cyclic silane compound can also be identified because it shows a peak in ²⁹ Si-NMR chemical shift according to its structure.

In the present embodiment, the silicone modifier is preferably 0.1 to 200% by mass, more preferably 0.1 to 120% by mass, and still more preferably 0 to the total mass of the ethylenically unsaturated monomer. .1 to 80% by mass, more preferably 1 to 10% by mass.
In the present embodiment, the glass transition temperature (Tg) of the acrylic resin (x) is −5 ° C. or lower. The glass transition temperature of the acrylic resin (x) is generally adjusted by the glass transition temperature of the homopolymer of the monomer used for copolymerization and the copolymer composition. When n-butyl acrylate (about −40 ° C.) having a low glass transition temperature or 2-ethylhexyl acrylate (about −60 ° C.) is used in a large amount, the glass transition temperature of the copolymer resin is low, and the meta having a high glass transition temperature. When methyl acrylate (about 90 ° C.) is used, the glass transition temperature of the copolymer resin is increased.

The acrylic emulsion used in the present embodiment preferably uses a small amount of a polyfunctional monomer and a chain transfer agent with respect to 100 parts by mass of the ethylenically unsaturated monomer.
Examples of chain transfer agents include dimers of nucleus-substituted α-methylstyrene such as α-methylstyrene dimer, n-butyl mercaptan, n-octyl mercaptan, n-lauryl mercaptan, n-dodecyl mercaptan and t-dodecyl mercaptan. Etc., disulfides such as tetramethylthiuram disulfide and tetraethylthiuram disulfide, 2-ethylhexyl thioglycolate, terpinolene and the like can be used alone or in combination of two or more. Among these, alkanethiol is preferable because of its high chain transfer speed and good physical property balance of the resulting resin. These chain transfer agents may be used alone or in combination of two or more. These chain transfer agents are mixed with the monomer and supplied to the reaction system, or are added alone in a predetermined amount at a predetermined time. The amount of these chain transfer agents to be used is preferably 0.2 parts by mass or more from the viewpoint of initial adhesion with respect to 100 parts by mass of the ethylenically unsaturated monomer. It is preferable that it is 1.2 mass parts or less from a viewpoint of keeping the adhesiveness at the time favorable.

  In this Embodiment, the said acrylic resin (x) is 0.2-1.2 mass parts of chain transfer agents with respect to 100 mass parts of ethylenically unsaturated monomers, and polyfunctional monomer 0. It is preferably obtained by polymerizing a mixed monomer containing 2 to 5 parts by mass, and a mixture containing 0.4 to 1.0 parts by mass of a chain transfer agent and 0.4 to 3 parts by mass of a polyfunctional monomer More preferably, it is obtained by polymerizing monomers.

The emulsifier used in this embodiment includes an ethylenically unsaturated monomer having a sulfonic acid group (—SO ₃ H) or a sulfonate group (—SO ₃ M), a sulfate group (—OSO ₃ H or OSO ₃ M). In order to achieve high water resistance of the resin layer (B), it is preferable to include at least one of the ethylenically unsaturated monomers having).

Examples of the ethylenically unsaturated monomer having a sulfonic acid group or a sulfonate group used in the present embodiment include a radical polymerizable double bond and a free sulfonic acid group or an ammonium salt or alkali metal thereof. Examples thereof include compounds having a salt group (ammonium sulfonate group or alkali metal sulfonate group).
Alkyl group having 1 to 20 carbon atoms, alkyl ether group having 2 to 4 carbon atoms, and polyalkyl ether having 2 to 4 carbon atoms, partially substituted by a group that is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group Vinyl bonded to a group having a substituent selected from the group consisting of a group, an aryl group having 6 or 10 carbon atoms and a succinic acid group, or a ammonium salt, sodium salt or potassium salt of a sulfonic acid group Vinyl sulfonate compounds having groups are preferred.

  A specific example of the succinic acid compound partially substituted with a group that is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group used in the present embodiment is allyl sulfosuccinate, for example, the following formula (5) The compound represented by-(8) is mentioned.

(In the formulas (5) to (8),
R ⁸ is hydrogen or a methyl group,
R ⁹ is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, a hydrocarbon group that is an aralkyl group having 7 to 19 carbon atoms, or a part thereof. Hydroxyl group or polyoxyalkylene alkyl ether group substituted with a hydroxyl group, a carboxylic acid group (the alkyl part has 1 to 20 carbon atoms and the alkylene part has 2 to 4 carbon atoms) or polyoxyalkylene alkyl phenyl ether A group (wherein the alkyl moiety has 1 to 20 carbon atoms and the alkylene moiety has 2 to 4 carbon atoms),
A is an alkylene group having 2 to 4 carbon atoms or an alkylene group in which part of hydrogen of the alkylene group is substituted with a hydroxyl group or a carboxylic acid group,
M is ammonium, sodium or potassium;
n is an integer of 0-200. )

Examples of the emulsifier containing the compounds represented by the formulas (5) and (6) include Eleminol JS-2, JS-5 (registered trademark, manufactured by Sanyo Chemical Industries, Ltd.), and the formula (7). Examples of the emulsifier containing (8) include Latemulu S-120, S-180A, S-180 (registered trademark, manufactured by Kao Corporation), and the like.
Specific examples of the compound having an aryl group partially substituted with a sulfonate group include ammonium p-styrenesulfonate, sodium salt and potassium salt. Specific examples of the compound having an alkyl group partially substituted by a sulfonate group include ammonium salt, sodium salt and potassium salt of methylpropanesulfonic acid acrylamide, ammonium salt of acrylic acid sulfoalkyl ester, sodium salt and potassium salt, ( Examples thereof include ammonium, sodium and potassium salts of (meth) acrylic acid sulfoalkyl esters.

  The ethylenically unsaturated monomer having a sulfate group used in the present embodiment is a compound having a radical polymerizable double bond and a group which is a sulfate group or an ammonium salt or an alkali metal salt thereof. Say. Among these, a C1-C20 alkyl group, a C2-C4 alkyl ether group, a C2-C2 partly substituted by the group which is an ammonium salt of a sulfate ester group, sodium salt, or potassium salt. A compound having a group selected from the group consisting of 4 polyalkyl ether groups and aryl groups having 6 or 10 carbon atoms is preferred.

  The alkyl ether group having 2 to 4 carbon atoms or the polyalkyl ether group having 2 to 4 carbon atoms partially substituted with a group that is an ammonium salt, sodium salt, or potassium salt of a sulfate ester group used in this embodiment Specific examples of the compound include compounds represented by the following formulas (9) to (11).

(Where
R ¹⁰ is an alkyl group, alkenyl group or aralkyl group having 6 to 18 carbon atoms,
R ¹¹ is an alkyl group having 6 to 18 carbon atoms, an alkenyl group or an aralkyl group,
R ¹² is hydrogen or a propenyl group;
A is an alkylene group having 2 to 4 carbon atoms,
M is an ammonium, sodium, potassium or alkanolamine residue;
n is an integer of 1 to 200. )

(Where
R ¹³ is hydrogen or a methyl group,
R ¹⁴ is an alkyl group having 8 to 24 carbon atoms, an alkylphenyl group or an acyl group,
A is an alkylene group having 2 to 4 carbon atoms,
M is an ammonium, sodium, potassium or alkanolamine residue;
l is an integer from 0 to 50;
n is an integer of 0-20. )

(Where
R ¹⁵ is hydrogen or a methyl group;
R ¹⁶ is an alkyl group having 8 to 30 carbon atoms,
A is an alkylene group having 2 to 4 carbon atoms or a hydrogen atom part of the alkylene group substituted with a hydroxyl group or a carboxylic acid group,
M is an ammonium, sodium, potassium or alkanolamine residue, and n is an integer of 0 to 200. )

  Examples of the compound represented by the formula (9) include Aqualon HS-10 (registered trademark, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Examples of the compound represented by the formula (10) include Adekaria. Soap SE-1025A, SR-10N, SR-20N (product name, manufactured by ADEKA Co., Ltd.) and the like are exemplified. As the compound represented by the formula (11), for example, Aqualon KH-10, KH-05 (registered) Trademark, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

In the present embodiment, the ethylenically unsaturated monomer having a sulfonic acid group, a sulfonate group or a sulfate ester group used as an emulsifier exists in the emulsion as a copolymer obtained by radical polymerization on emulsion particles, or is not yet present. Adsorbed to emulsion particles as a reactant or present in the emulsion aqueous phase, or adsorbed to emulsion particles as a copolymer with water-soluble monomers or as a copolymer of ethylenically unsaturated monomers used as emulsifiers Or present in the emulsion aqueous phase.
Especially, the moisture resistance of the resin layer (B) obtained from an emulsion can be made high by raising the ratio which exists in the state of the copolymer which carried out radical polymerization to emulsion particle | grains.

The ethylenically unsaturated monomer used as the emulsifier can identify each substance by pyrolysis gas chromatogram mass spectrometry (Py-GC-MS) of the resin layer (B) obtained from the emulsion.
In the present embodiment, the emulsifier is preferably used in an amount of 0.05 mass% to 10 mass%, more preferably 0.1 mass% to 5 mass%, based on the total mass of the ethylenically unsaturated monomer. It is done.

  In the present embodiment, in addition to an emulsifier containing an ethylenically unsaturated monomer having a sulfonic acid group, a sulfonate group or a sulfate ester group, an ordinary surfactant can be used in combination. Examples of the surfactant include anionic surfactants such as fatty acid soaps, alkyl sulfonates, alkyl sulfosuccinates, polyoxyethylene alkyl sulfates, polyoxyethylene alkyl aryl sulfates, and polyoxyethylene alkyl aryl ethers. , Non-reactive nonionic surfactants such as polyoxyethylene sorbitan fatty acid ester and oxyethylene oxypropylene block copolymer, Adeka Soap NE-20, NE-30, NE-40 (product name, manufactured by ADEKA Corporation) α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene or Aqualon RN-10, RN-20, RN-30, RN-50 (registered trademark, first Polio such as Kogyo Seiyaku Co., Ltd. A nonionic surfactant that can be copolymerized with an ethylenically unsaturated monomer, which is called a reactive nonionic surfactant such as xylethylenealkylpropenyl phenyl ether, can be used in combination.

The amount of the surfactant used is preferably 0.5% by mass or less, more preferably 0.25% by mass or less for the anionic surfactant, based on the total mass with the ethylenically unsaturated monomer. The non-reactive nonionic surfactant and the reactive nonionic surfactant are preferably 2.0% by mass or less, more preferably 1.0% by mass or less. When the surfactant is used within this range, the resin layer (B) having good moisture resistance can be formed.
In the present embodiment, the acrylic emulsion and the silicone-modified acrylic emulsion are preferably blended with an ultraviolet absorber and / or a light stabilizer, so that the resin layer (B) imparted with high weather resistance can be obtained. Can be obtained. Further, an acrylic emulsion and a silicone-modified acrylic emulsion may be obtained by copolymerizing a light stabilizer.

  As a method of adding an ultraviolet absorber and / or a light stabilizer to an acrylic emulsion and a silicone-modified acrylic emulsion, a film-forming aid or the like is mixed in each emulsion and then an ultraviolet absorber and / or a light stabilizer is added. However, in order to develop light resistance and durability over a longer period, it is preferable that an ultraviolet absorber and / or a light stabilizer be present during emulsion polymerization. The ultraviolet absorber and / or light stabilizer is preferably used in an amount of 0.1 to 20 mass%, more preferably 0.1 to 10 mass%, based on the total mass with the ethylenically unsaturated monomer. Also, use a radical polymerizable compound having a radical polymerizable double bond in the molecule as the ultraviolet absorber, and a radical polymerizable compound having a radical polymerizable double bond in the molecule as the light stabilizer. You can also. Moreover, when an ultraviolet absorber and a light stabilizer are used in combination, a resin layer (B) having a more excellent weather resistance when the film is formed using the highly durable emulsion can be obtained.

As the ultraviolet absorber used in the present embodiment, it is preferable to use at least one selected from benzophenone, benzotriazole, and triazine. As the light stabilizer used in the present embodiment, for example, a hindered amine compound is used. It is preferable to use it. Combining a highly durable silicone-modified acrylic emulsion with a benzophenone-based, benzotriazole-based, triazine-based UV absorber and / or light stabilizer with high UV-absorbing ability provides excellent durability due to a synergistic effect.
Among them, a combination of a benzotriazole ultraviolet absorber and a light stabilizer is more preferable.

  Specific examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, and 2-hydroxy. -4-n-octyloxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2, 2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2- Hydroxy-4-meth Shi-2'-carboxybenzophenone, 2-hydroxy-4-stearyloxy benzophenone.

  Examples of radical polymerizable benzophenone UV absorbers include 2-hydroxy-4-acryloyloxybenzophenone, 2-hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-5-acryloyloxybenzophenone, 2-hydroxy-5-methacryloyl. Oxybenzophenone, 2-hydroxy-4- (2-acryloyloxyethyloxy) benzophenone, 2-hydroxy-4- (2-methacryloyloxyethyloxy) benzophenone, 2-hydroxy-4- (methacryloxy-diethoxy) benzophenone, 2- And hydroxy-4- (acryloxy-triethoxy) benzophenone.

  Specific examples of the benzotriazole UV absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole and 2- (2′-hydroxy-5′-tert-butylphenyl). ) Benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- ( 2′-hydroxy-3 ′, 5′-di-tert-octylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α′-dimethylbenzyl) phenyl] benzotriazole, Methyl-3- [3′-tert-butyl-5 ′-(2H-benzotriazol-2-yl) -4′-hydroxypheny [Lu] Condensation of propionate and polyethylene glycol (molecular weight 300) (product name: TINUVIN (registered trademark) 1130, manufactured by Ciba Geigy Japan, Inc.), isooctyl-3- [3 '-(2H-benzotriazol-2-yl) -5′-tert-butyl-4′-hydroxyphenyl] propionate (manufactured by Ciba Geigy Japan, product name: TINUVIN (registered trademark) 384), 2- (3′-dodecyl-5′-methyl-2-hydroxyphenyl) ) Benzotriazole (manufactured by Ciba Geigy Japan, product name: TINUVIN (registered trademark) 571), 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2 -(2'-hydroxy-3 ', 5'-di-tert-amylphenyl) Benzotriazole, 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydro Phthalimidomethyl) -5'-methylphenyl] benzotriazole, 2,2-methylenebis [4 '-(1 ", 1", 3 ", 3" -tetramethylbutyl) -6'-(2H- Benzotriazol-2 ″ -yl) phenol], 2- (2H-benzotriazol-2′-yl) -4,6-bis (1′-methyl-1′-phenylethyl) phenol (manufactured by Ciba-Geigy Japan) , Product name: TINUVIN (registered trademark) 900) and the like.

As a radical polymerizable benzotriazole-based ultraviolet absorber, 2- [2′-hydroxy-5 ′-(2 ″ -methacryloyloxyethyl) phenyl)))-2H-benzotriazole (manufactured by Otsuka Chemical Co., Ltd., Product name: RUVA-93), 2- [2'-hydroxy-5 '-(2-methacryloyloxyethyl) -3'-tert-butylphenyl)))-2H-benzotriazole, 2- [2'-hydroxy -5 ′-(3-methacryloyloxypropyl) -3′-tert-butylphenyl)))-5-chloro-2H-benzotriazole, 3-methacryloyl-2-hydroxypropyl-3- [3 ′-(2 ′ '-Benzotriazolyl) -4'-hydroxy-5'-tert-butyl] phenylpropionate (manufactured by Ciba Geigy Japan, product name: CGL 104), and the like.
As the benzotriazole-based ultraviolet absorber, TINUVIN (registered trademark) 384 is preferable.

Specific examples of the triazine-based ultraviolet absorber include TINUVIN 400, TINUVIN 405, TINUVIN 460, TINUVIN 477DW, and TINUVIN 479 (registered trademark, manufactured by Ciba-Geigy Corporation).
As the triazine-based ultraviolet absorber, TINUVIN400 is preferable.
As the light stabilizer, those having low basicity are preferable, and those having a basic constant (pKb) of 8 or more are more preferable.
Specific examples include hindered amine compounds such as bis (2,2,6,6-tetramethyl-4-piperidyl) succinate and bis (2,2,6,6-tetramethyl-4-piperidyl). ) Sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-butylmalonate, 1- [2 -[3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethy Mixture of -4-piperidyl-sebacate (manufactured by Ciba Geigy Japan, product name: TINUVIN (registered trademark) 292), bis (1-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, TINUVIN123 (Registered trademark, manufactured by Nippon Ciba-Geigy Co., Ltd.).

Examples of the radical polymerizable light stabilizer include 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (manufactured by ADEKA, product name: ADK STAB LA82), 1,2,2,6,6-pentamethyl. -4-piperidyl acrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate (manufactured by ADEKA, product name: ADK STAB LA87), 2,2,6,6-tetramethyl-4-piperidyl acrylate, 1,2,2,6,6-pentamethyl-4-iminopiperidyl methacrylate, 2,2,6,6, -tetramethyl-4-iminopiperidyl methacrylate, 4-cyano-2,2,6,6-tetramethyl -4-piperidyl methacrylate, 4-cyano-1,2,2,6,6-pentamethyl-4-piperidylmethacrylate Such as theft and the like.
As the light stabilizer, TINUVIN (registered trademark) 123 is preferable.

In the present embodiment, emulsion polymerization can be performed by causing addition polymerization of an ethylenically unsaturated monomer by radical decomposition using heat or a reducing substance, using a polymerization initiator.
As the polymerization initiator for emulsion polymerization, water-soluble or oil-soluble persulfates, peroxides, azobis compounds, and the like can be used.

Specifically, for example, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate, peroxides such as hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 2,2- Examples thereof include azobis compounds such as azobisisobutyronitrile, 2,2-azobis (2-diaminopropane) hydrochloride, and 2,2-azobis (2,4-dimethylvaleronitrile).
It is preferable to use potassium persulfate, sodium persulfate, or ammonium persulfate. These polymerization initiators can be used as a catalyst for accelerating the hydrolysis reaction and condensation reaction of the silicone modifier when obtaining a silicone-modified acrylic emulsion. effective.
As a quantity of the said polymerization initiator, 0.05 mass%-1 mass% can be normally used with respect to the total mass with an ethylenically unsaturated monomer.

In the present embodiment, the emulsion polymerization reaction is preferably performed at a reaction temperature of 65 to 90 ° C. under normal pressure. However, the emulsion polymerization reaction may be performed under high pressure in accordance with characteristics such as vapor pressure at the reaction temperature of the monomer. it can.
In the present embodiment, the reaction time for emulsion polymerization is the sum of the introduction time and the aging time after the introduction. The introduction time is usually several minutes when various raw materials are simultaneously introduced into the reaction system, and when various raw materials are sequentially introduced into the reaction system, the various raw materials are introduced into the reaction system within a range where heat generated by polymerization can be removed. Therefore, although it depends on the polymer concentration in the finally obtained emulsion, it is usually 10 minutes or more. The aging time after the introduction is preferably at least 10 minutes or more.
By setting the aging time to 10 minutes or more, the time is sufficient to react each raw material. Moreover, when manufacturing a silicone modified acrylic emulsion, it can be made time sufficient to condense after hydrolyzing a silicone modifier.
When acceleration of the polymerization rate and polymerization at a low temperature of 70 ° C. or lower are desired, it is preferable to use a reducing agent such as sodium bisulfite, ferrous chloride, ascorbate, or longalite in combination with the radical polymerization catalyst. Furthermore, a chain transfer agent such as dodecyl mercaptan can be optionally added to adjust the molecular weight of the polymer in the resulting silicone-modified acrylic emulsion.

The acrylic emulsion used in the present embodiment includes, for example, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, octylic acid as a curing catalyst at the time of film formation for forming the resin layer (B) after completion of emulsion polymerization. Metal salts of organic acids such as tin, tin laurate, iron octylate, lead octylate, tetrabutyl titanate, and amine compounds such as n-hexylamine and 1,8-diazabicyclo [5,4,0] -7-undecene Can also be added.
When these curing catalysts are not water-soluble, they are preferably emulsified with a surfactant and water before use.

The acrylic emulsion used in this embodiment can be adjusted to a pH range of 5 to 10 using amines such as ammonia, sodium hydroxide, potassium hydroxide, and dimethylaminoethanol in order to maintain long-term stability of the emulsion dispersion. preferable.
In the present embodiment, after completion of emulsion polymerization, concentration may be performed in order to evaporate and remove unreacted monomer volatile substances, water, alcohol, and the like.
The average particle size of the dispersoid such as an acrylic emulsion used in the present embodiment is preferably 10 to 1,000 nm.
Further, the mass ratio (dispersion medium / dispersoid) of the dispersoid (solid content) in the obtained emulsion to the aqueous medium as the dispersion medium is preferably 70/30 or less, more preferably 30/70 to 65 /. 35 or less.
In the acrylic emulsion used in the present embodiment, a film-forming aid, a thickener, an antifoaming agent, a pigment, a dispersant, a dye, a preservative, and the like can be arbitrarily blended.

  Specific examples of the film forming aid include diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol mono 2-ethylhexyl ether, 2,2,4-trimethyl-1,3-butane. Examples include diol isobutyrate, diisopropyl glutarate, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, dipropylene glycol methyl ether, and tripropylene glycol methyl ether. These film-forming aids can be blended alone or arbitrarily in combination.

(Method for forming resin layer (B))
As a method for forming the resin layer (B) from the acrylic emulsion used in the present embodiment, there are methods such as coating (coating) and film formation, but in consideration of the insulating properties of the protective sheet (C), A method of forming an acrylic emulsion by coating (coating) and drying is preferred.
The concentration of the coating solution at this time is preferably 1 to 70% by mass, and drying is preferably performed at 20 to 150 ° C. The emulsion can be applied by various methods such as gravure coating, wire bar coating, air knife coating, die coating, lip coating, and comma coating.

  In this Embodiment, in order to increase the adhesive force with a resin layer (B), it is preferable to perform a corona discharge process to the application surface of a protective sheet prior to application | coating of an acrylic emulsion.

(White enamel paint)
In the present embodiment, the resin layer (B) made of the acrylic resin (x) may be formed by applying (coating) an enamel paint, which is an acrylic emulsion containing a pigment, and drying. The pigment is not particularly limited, but a white pigment is preferable, and inorganic such as zinc oxide, lead white, calcium carbonate, lithopone (mixture of zinc sulfide and barium sulfate), titanium dioxide, precipitated barium sulfate and barite powder. Pigments and organic pigments such as polystyrene copolymer particles can be used. The white enamel paint refers to an acrylic emulsion containing these white pigments, and includes a dispersant, a pH adjuster, an antifoaming agent, a thickener, a film-forming aid (organic solvent) and the like as necessary. Also good. As the film forming aid, those described above can be used.

The blending ratio of the pigment and the acrylic resin (x) is preferably 20 to 60% by mass of the pigment and 40 to 80% by mass of the acrylic resin (x) in the mass ratio in the coating film after coating and drying. It is more preferable that they are 30-50 mass% of pigments, and 50-70 mass% of acrylic resin (x).
By setting the mass ratio of the pigment to 20% by mass or more, the opacity of the coating film is improved, and in the case of a white pigment, light incident from the surface of the photovoltaic cell can be efficiently reflected. On the other hand, when the content is 60% by mass or less, the film formability of the coating film and the weather resistance in the natural environment are improved.

In order to improve the weather resistance, it is preferable to use the above-mentioned silicone-modified acrylic emulsion.
The resin layer (B) preferably contains a UV absorber and / or a light stabilizer from the viewpoint of light resistance, and the UV absorber and / or light is added to the acrylic emulsion or the silicone-modified acrylic emulsion. It may be obtained by copolymerizing a stabilizer.

[Protective sheet (C)]
There is no restriction | limiting in particular as a protective sheet (C), A well-known thing can be used. For example, when using the laminate of the present embodiment for a solar cell module as a solar cell protective member, because it is located on the outermost layer of the solar cell module, including weather resistance, water repellency, contamination resistance, mechanical strength, It is preferable that the solar cell module has performance for ensuring long-term reliability in outdoor exposure.
Examples of the material of the protective sheet (C) include a resin film made of a polyester resin, a fluorine resin, an acrylic resin, a cyclic olefin (co) polymer, an ethylene-vinyl acetate copolymer, a glass substrate, and the like. . In particular, a polyester resin and a glass substrate can be preferably used, and among them, a polyethylene terephthalate resin (PET) is more preferable from the viewpoint of weather resistance, strength, and cost. Among these, it is preferable to contain a polyester resin or a fluorine resin.

  A fluororesin having particularly good weather resistance is also preferably used. Specifically, tetrafluoroethylene-ethylene copolymer (ETFE), polyvinyl fluoride resin (PVF), polyvinylidene fluoride resin (PVDF), polytetrafluoroethylene resin (TFE), tetrafluoroethylene-6 Examples thereof include a fluorinated propylene copolymer (FEP) and a poly (trifluorotrifluoroethylene resin) (CTFE). A polyvinylidene fluoride resin is preferable from the viewpoint of weather resistance, but an ethylene tetrafluoride-ethylene copolymer is preferable from the viewpoint of achieving both weather resistance and mechanical strength. Moreover, it is preferable to perform a corona treatment and a plasma treatment to the protective sheet (C) in order to improve the adhesiveness with the material constituting the resin sealing sheet (A). Moreover, in order to improve mechanical strength, it is also possible to use a sheet that has been subjected to a stretching treatment, for example, a biaxially stretched polypropylene sheet.

  Since the protective sheet (C) does not assume the passage of sunlight, transparency (translucency) is not necessarily required. Therefore, a reinforcing plate may be attached to increase the mechanical strength of the solar cell module or to prevent distortion and warpage due to temperature change. For example, a steel plate, a plastic plate, an FRP (glass fiber reinforced plastic) plate or the like can be preferably used.

  Further, the protective sheet (C) may have a multilayer structure composed of two or more layers. Examples of the multilayer structure include a structure in which one or two or more layers of the same component are laminated on both sides of the central layer so as to be symmetrical with respect to the central layer. Preferred examples of such a structure include PET / alumina-deposited PET / PET, PVF (trade name: Tedlar (registered trademark)) / PET / PVF, and PET / AL foil / PET.

Since a weather resistance is calculated | required by a protective sheet (C), it is preferable to have moderate water vapor | steam barrier property. The water vapor transmission rate of the protective sheet (C) measured under conditions of a temperature of 40 degrees and a humidity of 90% RH is preferably 2.0 g / m ² / day or less, more preferably 0.5 g / m ² / day or less, more preferably not more than 0.1g / m ² / day, particularly preferably not more than 0.00001g / m ² / day, most preferably 0g / m ² / day. In this Embodiment, the water vapor transmission rate of a protection sheet (C) is a value obtained by the water vapor transmission rate measurement according to JIS-K-7129.

  In order to achieve the above water vapor transmission rate, there is no particular limitation, and a known one can be used. The protective sheet (C) used in the present embodiment includes a vapor deposition layer and / or a water vapor barrier layer, and the vapor deposition layer is selected from the group consisting of alumina, silica, alumina-silica, inorganic particles, and inorganic oxides. Preferably, the water vapor barrier layer is a layer containing at least one selected from the group consisting of a coating layer, an aluminum foil and a PET film.

[Production method of laminate]
As described above, the method for laminating the resin sealing sheet (A), the resin layer (B), and the protective sheet (C) is not particularly limited, and includes a dry laminating method, an extrusion laminating method, a sand laminating method, a wet laminating method, and the like. A known method can be used.
When the resin layer (B) is formed from an emulsion, it is more preferable to produce a laminate by a dry lamination method. By using the dry laminating method, the formation of the resin layer (B) can be easily controlled from the emulsion, and the adhesive force can be fully utilized. The protective sheet (C) is previously subjected to corona treatment, the resin layer (B) is formed thereon, dried, and the resin sealing sheet (A) is pressure-bonded to produce the laminate of the present embodiment. it can. When the adhesive layer of the resin layer (B) is formed from the emulsion, there is an advantage that the aging time required when the resin layer (B) is adhered by dry lamination using a conventional urethane adhesive or the like becomes unnecessary.

[Solar cell module manufacturing method]
The solar cell module of the present embodiment uses a laminate as a solar cell protective member.
When the laminate of this embodiment is used as a protective member for a solar cell power generation element, it can be used as a known solar cell protective member such as a silicon crystal type or a thin film type. The vacuum laminating conditions at the time of producing the module can be the laminating conditions in consideration of the temperature and time required for the resin sealing sheet, the power generation element, and the like. In the case of a silicon crystal solar cell, the size of the transparent protective member such as glass or resin on the light receiving surface side, or in the case of a thin film solar cell, the same size or a small size as the size of the glass on which the power generation element is deposited. Any of large sizes can be laminated. When a module is produced using the laminate of the present embodiment in which a resin sealing sheet is previously cross-linked, the same size is more preferable for improving workability.

[Use of laminate]
The laminate according to the present embodiment is particularly effective as a member for protecting members such as a power generation element constituting the solar cell. That is, it has excellent creep resistance and good adhesion to the object to be sealed, and the composition of the resin layer (B) can be changed or the adhesive component of the resin sealing sheet (A) can be changed according to the application. By controlling, adhesiveness can be controlled. By using the laminate of the present embodiment, various members having irregularities such as the solar cell glass itself, various wirings, and power generation elements can be reliably sealed without gaps.
Further, the laminate of the present embodiment can be used as a sealing sheet for solar cells, and can also be used for LED sealing and the like.

  Unless otherwise specified, each parameter described above is measured according to the measurement method in Examples described later.

Hereinafter, the present embodiment will be specifically described with reference to examples and comparative examples, but the present embodiment is not limited to these examples. In Examples 1-35 and Comparative Examples 2 and 3, laminates were produced in which the protective sheet was laminated on the resin sealing sheet via the resin layer.
The measurement method and evaluation method of each physical property and each material in Examples and Comparative Examples were as follows.

<Gel fraction>
The gel fraction of the resin sealing sheet produced by the production method shown below was determined as follows.
In the boiling p-xylene, the resin-encapsulated sheet was extracted for 12 hours, and the proportion of the insoluble portion was determined by the following formula as the total layer gel fraction. The gel fraction was evaluated as a measure of the degree of crosslinking of the resin sealing sheet.
Gel fraction (mass%) = (sample weight after extraction / sample weight before extraction) × 100
Regarding the gel fraction of the layer in contact with the object to be sealed, a sheet having the same resin and the same thickness as the layer in contact with the object to be sealed was prepared, and this sheet was subjected to electron beam irradiation treatment. The rate was calculated.

<Irradiation treatment>
The resin encapsulated sheet was subjected to electron beam treatment using an EPS-300 or EPS-800 electron beam irradiation apparatus (manufactured by Nisshin High Voltage) at a predetermined acceleration voltage and irradiation density.

<Density>
The density of the raw material of the resin sealing sheet (A) was measured according to JIS-K-7112.
<MFR>
The melt flow rate (MFR) of the raw material of the resin sealing sheet (A) was measured according to JIS-K-7210.

<Melting point>
The melting point of the raw material of the resin sealing sheet (A) was measured as follows.
Using a differential scanning calorimeter “MDSC 2920 type” manufactured by TI Instruments Inc., about 5 mg of resin was heated from 0 ° C. to 200 ° C. at a rate of 20 ° C./min, and melted and held at 200 ° C. for 5 minutes. The temperature of the endothermic peak accompanying melting obtained when the temperature was lowered later at a rate of 20 ° C./min to −50 ° C. or less and then increased from 0 ° C. to 200 ° C. at 20 ° C./min was taken as the melting point.

<Evaluation of gap filling ability of power generation element>
About the solar cell sample (I) produced by the Example and the comparative example, the contact condition (gap filling property) of the crystalline silicon cell for a power generation element and a resin sealing sheet was confirmed visually.
(Evaluation criteria for gap filling properties)
(Double-circle): It was sealed without a space | gap and a crack around a cell.
X: A gap was observed around the cell.

<Evaluation of dirtiness of laminating equipment>
For the solar cell samples (I) produced in the examples and comparative examples, during the production, the state of the laminate flowing out from the gap between the solar cell glass plate and the protective sheet was visually observed, and the laminating property of the laminating apparatus was observed. evaluated.
(Evaluation criteria for dirtiness of laminating equipment)
A: Outflow of the laminate was not observed (very good).
○: Outflow of the laminate was observed, but the ratio of the outflow width to the peripheral length of the solar cell glass plate was 50% or less (good).
X: The outflow of the laminate was observed, and the ratio of the outflow width to the peripheral length of the solar cell glass plate exceeded 50% (defective).

<Peeling strength between resin sealing sheet and protective sheet (before modularization)>
For evaluation, the produced laminate was cut into strips having a width of 10 mm, a part of the resin sealing sheet and the protective sheet were peeled off, and the strip-like sample was pulled at a rate of 100 mm / min by a T-type peeling method. The peel strength was measured. The measurement was performed three times, and the average value was evaluated in the following four stages.
(Evaluation criteria for peel strength)
A: 5 N or more (very good)
○: 2N or more and less than 5N (very good)
Δ: Over 0N and under 2N (good)
×: Not adhered at all (defect)

<Peeling strength between resin-sealed sheet and protective sheet (after modularization)>
About the sample (II) for evaluation produced by the Example and the comparative example, from the protective sheet side, a notch | incision is made to width 10mm, a part is peeled from a resin sealing sheet, and a strip-shaped sample is 100 mm / 180 degree direction. The film was pulled at a rate of min and the peel strength at that time was measured. The measurement was performed three times, and the average value was evaluated in the following four stages.
(Evaluation criteria for peel strength)
A: 5 N or more (very good)
○: 3N or more and less than 5N (very good)
Δ: 2N or more and less than 3N (good)
X: Less than 2N or peels off naturally (defect)

<Weather resistance test>
The laminates produced in Examples and Comparative Examples and Sample (II) were stored at 85 ° C. and 85% RH for 1000 hours. The peel strength between the resin sealing sheet and the protective sheet after 1000 hours was measured in the same manner as described above. The laminate was T-shaped, the sample (II) was in the 180 ° direction, a 10 mm wide sample was pulled at a rate of 100 mm / min, and the peel strength was measured. Further, the appearance change of the sample after the peel test was observed, and the evaluation was performed in the following three stages.
(Evaluation criteria for changes in peel strength)
A: Change in peel strength before and after storage is less than 20% (very good)
○: Change in peel strength before and after storage is 20% or more and less than 30% (good)
×: Change in peel strength between before and after storage is 30% or more (defect)
(Evaluation criteria for appearance changes)
A: No change in appearance (very good)
○: Almost no change in appearance (good)
×: Change in appearance (partial peeling, yellowing, poor appearance due to bubbles)
<Glass transition temperature (Tg)>
The acrylic emulsion was cast on a glass plate and heated and dried at 90 ° C. for 30 minutes to form a film. Next, the obtained film is put into a Tg measuring container, covered, set on a differential scanning calorimeter (manufactured by Seiko Electronics Co., Ltd.), and measured at a heating rate of 10 ° C./min. The temperature (Tg) was determined.
Each material used in the examples and comparative examples is as follows.

<Raw material of resin sealing sheet (A)>
(1) Ethylene-vinyl acetate copolymer (EVA)
EVANEE 28-05 made by Arkema
Tosoh Ultrasen 751
(2) Ethylene-glycidyl methacrylate-vinyl acetate copolymer Sumitomo Chemical Co., Ltd. Bond Fast 7B (BF7B)
(3) AFFINITY KC8852 (KC8852) manufactured by Dow Chemical Co., Ltd.
AFFINITY PF1140G (PF1140) manufactured by Dow Chemical
ENGAGE 8200 (EG8200) manufactured by Dow Chemical
(4) Olefin Block Copolymer INFUSE 9107 manufactured by Dow Chemical Company
Table 16 shows the physical properties of the raw materials in the above (1) to (4).

(5) Organic peroxide 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (Lupelox 101 manufactured by Arkema Yoshitomi)
(6) Silane coupling agent 3-methacryloxypropyltrimethoxysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.)

<Transparent insulating plate>
AGC glass plate for solar cells <Protective sheet (C)>
Protective sheets α and β shown in Table 9 (manufactured by M Packaging)
<Solar cell>
Crystalline silicon cell manufactured by E-TON <Raw material of resin layer (B) (emulsion containing acrylic resin (x))>
Emulsion (acrylic emulsion) containing acrylic resin (x) produced by the method shown in [Production Example 1] to [Production Example 23] below
The raw materials for the acrylic emulsion were as follows.
Methyl methacrylate (MMA)
Butyl acrylate (BA)
2-ethylhexyl acrylate (2-EHA)
Methacrylic acid (MAA)
Acrylic acid (AA)
2-hydroxyethyl methacrylate (2-HEMA)
γ-methacryloxypropyltrimethoxysilane (AcSiO)
Methyltrimethoxysilane (Me-Si- (OMe) 3)
Dimethyldimethoxysilane (Me2-Si- (OMe) 2)
n-dodecyl mercaptan (n-DDM)
t-dodecyl mercaptan (t-DDM)
Trimethylolpropane triacrylate (A-TMPT)
Pentaerythritol tetraacrylate (A-TMMT)

<Manufacture of resin sealing sheet>
Hereinafter, it shows about the manufacturing method of the resin sealing sheet used for the Example and the comparative example.
Resin sealing sheets a to m were manufactured using the raw materials of the resin sealing sheet (shown for each physical property in Table 16) with the configurations and conditions shown in Tables 1 to 3.
Three extruders (surface layer extruder and inner layer extruder) were used for the production of each resin-encapsulated sheet. The raw materials shown in Tables 1 to 3 were introduced into each extruder, and a tube was formed by melt-extruding the resin onto the tube from an annular die connected to the extruder. Resin sealing sheets a to m were obtained by air-cooling the tubes formed by melt extrusion. In introducing the organic peroxide and the silane coupling agent, the raw material to be introduced was kneaded in advance at a concentration of about 5% by mass to form a master batch, which was diluted to the desired amount. In addition, in a table | surface, a layer ratio shows the ratio of the thickness of each layer when the thickness of the whole resin sealing sheet is set to 100.
Electron beam cross-linking treatment according to the irradiation conditions shown in Table 1 for resin sealing sheets a to f, Table 2 for resin sealing sheets h, and Table 3 for resin sealing sheets j and k Went. About each obtained resin sealing sheet, evaluation of the gel fraction was performed as mentioned above. The resin sealing sheets g and i were subjected to a crosslinking treatment during vacuum lamination by blending an organic peroxide. No crosslinking treatment was performed on the resin sealing sheets l and m.

<Manufacture of acrylic emulsion>
[Production Example 1]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 64 parts of water and 0.25 part of “AQUALON KH-10” (registered trademark, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 25% aqueous solution) Was introduced. Furthermore, 0.15 parts of ammonium persulfate (2% aqueous solution) was added to the reaction vessel while maintaining the reaction vessel temperature at 80 ° C.
Five minutes after the addition, an emulsion prepared as follows was dropped from the dropping tank to the reaction vessel over 150 minutes.
Preparation of emulsion:
24 parts of methyl methacrylate (MMA), 34 parts of butyl acrylate (BA), 37.5 parts of 2-ethylhexyl acrylate (2-EHA), 1 part of methacrylic acid (MAA), 1.5 parts of acrylic acid (AA) Parts, 2-hydroxyethyl methacrylate (2-HEMA) 2 parts, 0.7 parts of trimethylolpropane triacrylate (A-TMPT), 0.7 parts of n-dodecyl mercaptan (nDDM), “AQUALON KH-10” (Registered trademark, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 25% aqueous solution) 1.5 parts, 0.15 part of ammonium persulfate, and 69 parts of water were mixed with a homomixer at 6000 rpm for 5 minutes to prepare an emulsion. ]
After completion of the emulsified droplet dropping, the reaction vessel temperature was maintained at 80 ° C. for 60 minutes and then cooled to room temperature. Next, a 25% aqueous ammonia solution was added to the reaction vessel to adjust the pH to 8.0, and water was further added to adjust the solid content to 40% by mass to obtain an acrylic emulsion [1]. Moreover, the glass transition temperature (Tg) of the acrylic resin in the obtained acrylic emulsion [1] was measured as described above. The measurement results are shown in Table 4.

[Production Examples 2 to 13, 17 to 21]
Each acrylic emulsion [2] to [13] and [17] in the same manner as in [Production Example 1] except that the types and amounts of raw materials shown in Table 4, Table 5, Table 7 and Table 8 were used. To [21].
However, t-DDM in the table indicates t-dodecyl mercaptan, and A-TMMT indicates pentaerythritol tetraacrylate. Moreover, the glass transition temperature (Tg) of the acrylic resin in the obtained acrylic emulsions [2] to [13] and [17] to [21] was measured as described above. The measurement results are shown in Table 4, Table 5, Table 7, and Table 8.

[Production Example 14]
In a reaction vessel equipped with a stirrer, reflux condenser, two dripping tanks and a thermometer, 50.8 parts of water and “AQUALON KH-10” (registered trademark, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 25% aqueous solution) 1 Department was put in. Furthermore, 0.15 parts of ammonium persulfate (2% aqueous solution) was added to the reaction vessel while maintaining the reaction vessel temperature at 80 ° C.
Five minutes after the addition, the emulsified liquid and the mixed liquid prepared as described below were dropped from a separate dropping tank into the reaction vessel over 150 minutes.
Preparation of emulsion:
24 parts of methyl methacrylate (MMA), 34 parts of butyl acrylate (BA), 37.5 parts of 2-ethylhexyl acrylate (2-EHA), 1 part of methacrylic acid (MAA), 1.5 parts of acrylic acid (AA) Parts, 2-hydroxyethyl methacrylate (2-HEMA) 2 parts, "Aqualon KH-10" (registered trademark, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 25% aqueous solution) 1.5 parts, ammonium persulfate 0.15 parts And 69 parts of water were mixed with a homomixer at 6000 rpm for 5 minutes to prepare an emulsion. ]
Preparation of mixed solution:
4. Gamma-methacryloxypropyltrimethoxysilane (AcSiO) 0.3 part, methyltrimethoxysilane (Me-Si- (OMe) 3) 13.6 parts and dimethyldimethoxysilane (Me2-Si- (OMe) 2) 5. 4 parts were mixed to obtain a mixed solution. ]
After completion of the dropwise addition of the raw materials, the reaction vessel temperature was maintained at 80 ° C. for 60 minutes. Next, while maintaining the reaction vessel temperature at 80 ° C., 0.6 part of an aqueous ammonium hydroxide solution (25% aqueous solution) was added, maintained for 90 minutes, and cooled to room temperature. Thereafter, methanol and excess ammonia in the system are removed under reduced pressure by a rotary evaporator, and finally water is added to adjust the solid content to 40% by mass to obtain a silicone-modified acrylic emulsion [14] having a pH of 8.5. It was. Moreover, the glass transition temperature (Tg) of the acrylic resin in the obtained silicone-modified acrylic emulsion [14] was measured as described above. The measurement results are shown in Table 5.

[Production Examples 15 and 16]
Silicone-modified acrylic emulsions [15] and [16] were obtained in the same manner as in [Production Example 14] except that the amount of silane monomer shown in Table 6 was used. Moreover, the glass transition temperature (Tg) of the acrylic resin in the silicone-modified acrylic emulsions [15] and [16] was measured as described above. The measurement results are shown in Table 6.

[Production Example 22]
(Preparation of white enamel paint)
A mixture was obtained by mixing 175 parts of the acrylic emulsion [1] obtained in [Production Example 1], 30 parts of titanium oxide and 2 parts of a hindered amine light stabilizer (“TINUVIN292”). Furthermore, water was added to the said mixture, solid content rate was adjusted to 40 mass%, and the white enamel coating material was produced.

[Example 1]
<Manufacture of laminates>
The acrylic emulsion [1] obtained in Production Example 1 was applied to the surface of the protective sheet α subjected to corona treatment with a die coater to form a resin layer (B). On the formed resin layer (B), the resin sealing sheet a obtained above was laminated by a dry laminating method to produce a laminate. Each evaluation was performed as above-mentioned about the manufactured laminated body. The evaluation results are shown in Table 10.
Details of the used protective sheet are shown in Table 9. In addition, the dry lamination conditions were such that after the resin layer (B) was applied, it was dried at 80 ° C. for about 1 minute to coat the resin layer (B) to a thickness of 10 μm. In addition, the process of aging after crimping, drying, etc. was not performed.

<Production and evaluation of solar cell module (sample (I))>
Using the obtained laminate, a solar cell module (sample (I)) was produced according to the conditions shown in Table 10 as follows.
Glass plate for solar cell (white glass made by AGC, 15 cm × 15 cm: thickness 3.2 mm) / resin sealing sheet a / power generation cell (polycrystalline silicon cell: thickness 200 μm) / produced laminate (resin sealing sheet / Resin layer / protective sheet) was laminated in this order, and a solar cell sample (I) was produced by vacuum lamination under the conditions of 90 Pa, 150 ° C., 15 minutes using an LM50 type vacuum laminator (manufactured by NPC). . Each evaluation was performed as above-mentioned about the produced solar cell sample (I). The evaluation results are shown in Table 10.

<Preparation and evaluation of sample (II) for evaluation>
Using the obtained laminate, a sample (II) for evaluation was produced as follows according to each condition shown in Table 10.
Laminate LM50 vacuum laminating device (NPC) in the order of glass plate for solar cell (white glass 5 cm × 10 cm: thickness 3.2 mm) manufactured by AGC / made laminate (resin sealing sheet / resin layer / protective sheet). The sample (II) for evaluation was produced by carrying out vacuum lamination under the conditions of 90 Pa, 150 ° C., and 15 minutes. Each evaluation was performed as mentioned above about the produced sample (II) for evaluation. The evaluation results are shown in Table 10.

[Examples 2-35]
A laminate was produced in the same manner as in Example 1 except that the configuration of the laminate was as shown in Tables 10 to 14, and each evaluation was performed on the obtained laminate. The said evaluation result is shown to Tables 10-14.
Moreover, except having set it as the structure and conditions shown in Tables 10-14 using the obtained laminated body, it carried out similarly to Example 1, and carried out the solar cell module (sample (I)) and the sample (II) for evaluation. Each evaluation test was performed about the solar cell module (sample (I)) and evaluation sample (II) which were produced and obtained. The said evaluation result is shown to Tables 10-14.

[Comparative Example 1]
In Comparative Example 1, a sample was manufactured using a conventional module manufacturing method. Specifically, without using a resin layer containing an acrylic resin, the protective sheet α is directly laminated on the resin sealing sheet i shown in Table 2, and the solar cell module (sample (I)) is as follows. Produced.
From the light-receiving surface side, a glass plate for solar cells (white glass 15 cm × 15 cm: thickness 3.2 mm manufactured by AGC), resin sealing sheet i, power generation cell (polycrystalline silicon cell: thickness 200 μm), resin sealing sheet i The solar cell sample (I) was produced by laminating in the order of the protective sheet α and vacuum laminating under the conditions of 90 Pa, 150 ° C. and 15 minutes using an LM50 type vacuum laminator (manufactured by NPC). Each evaluation test mentioned above was done using produced solar cell sample (I). The evaluation results are shown in Table 15.
Moreover, sample (II) for evaluation was produced as follows according to each condition shown in Table 15 using the obtained laminate.
A glass plate for solar cells (white glass 5 cm × 10 cm manufactured by AGC, thickness 3.2 mm) / resin sealing sheet i / protective sheet α are laminated in this order, and 90 Pa using an LM50 vacuum laminating apparatus (NPC). Sample (II) for evaluation was produced by vacuum lamination under the conditions of 150 ° C. and 15 minutes. Each evaluation was performed as mentioned above about the produced sample (II) for evaluation. The evaluation results are shown in Table 15.

[Comparative Examples 2 and 3]
Comparative Example 2 and Comparative Example 3 were the same as in Example 1 except that the resin-encapsulated sheet i shown in Table 2 was used and the acrylic emulsions [20] and [21] produced in Production Examples 20 and 21 were used. Thus, a laminate of the resin sealing sheet and the protective sheet was obtained under the conditions shown in Table 15.
Further, using the obtained laminate, a solar cell module (sample (I)) and an evaluation sample (II) were prepared in the same manner as in Example 1 except that the configurations and conditions shown in Table 15 were used. Then, each evaluation test was performed on the obtained solar cell module (sample (I)) and evaluation sample (II). The evaluation results are shown in Table 15.

When a module is manufactured using the laminate of the present embodiment, the complexity of the work of stacking each member such as glass, resin encapsulated sheet, cell, etc. before the module manufacturing is reduced, and the module is manufactured with good workability. It was possible to do. Furthermore, since the resin sealing sheet and the protective sheet are integrated, the resin sealing sheet and the protective sheet are less likely to be displaced when the module is laminated, and the module can be manufactured without cell cracking. .
Even when the resin-encapsulated sheets a to k that have been subjected to crosslinking treatment are used, and when the resin-encapsulated sheet 1 of a thermoplastic elastomer is used, a protective sheet is formed by a resin layer containing an acrylic resin having a Tg of −5 ° C. or less. Since it was laminated | stacked, the adhesion | attachment with a weather resistance was shown rather than the case of the resin sealing sheet m which is not crosslinked.

  When the resin sealing sheet is cross-linked by ionizing radiation and an adhesive resin (BF7B) is used without using an organic peroxide or a silane coupling agent (resin sealing sheets a to f), a laminate The workability of the laminate in production was excellent. Since the resin sealing sheet was cross-linked at the time of laminating the laminate, the resin sealing sheet was not melted and caught in a roll of a machine for laminating, and the operability of the laminate for laminating was excellent. Furthermore, even when heated at the time of laminating the laminate, the organic peroxide and silane coupling agent are not included. It was maintained well after conversion.

In Example 1 to Example 35, since the module was manufactured using the laminate of the present embodiment, the protective sheet and the resin sealing sheet were integrated in advance. Therefore, the complexity of the lamination process is reduced, and the incidence of cell cracking is also reduced. As a result, productivity improved compared with the case of the comparative example 1 which laminates | stacks a protection sheet and a resin sealing sheet, respectively, and produces a module.
From the evaluation results of Examples 1 to 35 and Comparative Examples 2 and 3 (Tables 10 to 15), when an acrylic resin having a glass transition point of −5 ° C. or lower is used, a laminate and a module are produced. It can be seen that the initial adhesive force between the subsequent protective sheet and the sealing resin sheet was strong and also had sufficient weather resistance. Moreover, comparing Example 20, Example 21, and Example 22, it was found that the adhesiveness was better when the resin layer (B) containing an acrylic resin having a lower glass transition temperature was used. .

  Example 8, Example 9, Example 13 to Example 16, Example 1 to Example 7, Example 10 to Example 12, Example 17 to Example 19, and Example 21 to Example 35 In contrast, the latter had stronger initial adhesive strength of the laminate. This is because the acrylic resin in the resin layer (B) used in the latter laminate has a Tg of -5 ° C. or lower and 100 parts by mass of the ethylenically unsaturated monomer, a chain transfer agent of 0. This is considered to be because the mixed monomer composed of 2 to 1.2 parts by mass and 0.2 to 5 parts by mass of the polyfunctional monomer was polymerized.

  From the evaluation results (Tables 10 to 15) comparing Example 1 to Example 33 and Example 35 with Example 34, resin sealing using a resin sheet that has undergone crosslinking treatment and a resin that is a thermoplastic elastomer In the case of the laminate using the stop sheets (a to l), the adhesion was more weather resistant than in the case of the laminate using the resin-sealed sheet (m) that was not crosslinked. Since the rigidity of the resin encapsulating sheet is increased by the crosslinking treatment, it is generally considered that the adhesiveness with the rigid protective sheet is deteriorated, but the adhesiveness is improved by the presence of the resin layer (B) that can withstand the heat history. It is thought that it improved.

  Furthermore, Example 1 to Example 27, Example 29, Example 31, Example 32, and Example 35, Example 28, Example 30, Example 33, Example 34, and Comparative Example 1 to Comparative Example 3 From the evaluation results (Table 10 to Table 15) in comparison with the above, in the case of using a resin-sealed sheet (a to f, h, j, and k) that has been previously subjected to crosslinking treatment, during vacuum lamination for module production, The resin did not adhere to the laminator. In addition, in the laminate prepared from the resin layer made of an acrylic resin having adhesive strength, the vacuum laminating apparatus was less soiled even when a resin sealing sheet having no cross-linked structure was used.

  Evaluation comparing Example 1 to Example 27 and Example 29, Example 31, Example 32, and Example 35 with Example 28, Example 30, Example 33, and Comparative Example 1 to Comparative Example 3 From the results (Table 10 to Table 15), in the case of using the resin-encapsulated sheet (a to f, h, j, and k) having a gel fraction of 0.1 to 65%, before laminating the module, As in the case of using a resin-sealed sheet that has not been cross-linked, it can be seen that the gap filling property of the glass is good and the cell can be modularized without cracking.

  Example 1 to Example 27 and Example 29, Example 31, Example 32 to Example 33, and Example 35, Example 28, Example 30, Example 33, and Comparative Example 1 to Comparative Example 3 From the evaluation results (Table 10 to Table 15), the resin sealing sheet subjected to crosslinking treatment with ionizing radiation and the resin sealing sheet using a thermoplastic elastomer (a to f, h, j, and k, In the case of using l), the resin-sealed sheet was melted during the dry lamination for producing the laminate, and did not adhere to the roll and was excellent in operability. Also, in module production, there was a gap filling property, and the module could be produced without any problem. Furthermore, in the resin-encapsulated sheet subjected to the crosslinking treatment with ionizing radiation, it is considered that the adhesion stability with the resin layer containing the acrylic resin is improved by the crosslinking treatment with ionizing radiation.

Evaluation results comparing Example 1 to Example 28, Example 31, and Example 32 with Example 29, Example 30, Example 33 to Example 35, and Comparative Example 1 to Comparative Example 3 (Table 10) From Table 15), when the resin-encapsulated sheet (a to g, j, k) containing the adhesive resin (BF7B) was used, stable adhesiveness was observed even after the module was manufactured. This is presumably because the resin-sealing sheet does not contain a silane coupling agent that is decomposed by heat and the compatibility between glycidyl methacrylate and acrylic resin is good.
From the evaluation results (Table 10 to Table 15) comparing Example 1 to Example 27, Example 32, and Example 35 with Example 28 to Example 31, Example 33, and Comparative Example 1 to Comparative Example 3 When the resin sealing sheet was cross-linked by ionizing radiation and contained an adhesive resin (BF7B) (a to f, k), the obtained module had good weather resistance. The reason why the weather resistance was good is considered to be that deformation and deterioration of the resin sealing sheet at the time of lamination for producing a laminate are suppressed by performing a crosslinking treatment on the resin sealing sheet.

From a comparison between Example 35 and Examples 1 to 34, sufficient adhesiveness was exhibited even when the resin layer (B) was white.
Further, from the evaluation results shown in Table 10 to Table 15, the laminate of the present embodiment is used regardless of whether the laminate is the same size as the sample glass, large size or small size. Thus, it was found that good solar cells can be manufactured with good workability. Moreover, even when the material of the protective sheet is different, both the production of the laminate and the production of a good solar cell can be performed.

  As is clear from the above results, the laminate of the present embodiment includes a resin sealing sheet, a resin layer containing an acrylic resin having a glass transition temperature (Tg) of −5 ° C. or lower, and a protective sheet in this order. By laminating, the resin sealing sheet and the protective sheet are not misaligned and laminated at the time of module production, and the gap filling property and creep resistance are good, and the adhesion between the resin sealing sheet and the protective sheet is good. Was enough.

  The laminate of the present invention has industrial applicability as a sealing sheet for protecting members such as a power generation element constituting a solar cell.

Claims (14)

  The laminated body which laminated | stacked the resin sealing sheet (A), the resin layer (B) which consists of acrylic resin (x) whose glass transition temperature (Tg) is -5 degrees C or less, and the protection sheet (C) in this order.   The acrylic resin (x) is 0.2 to 1.2 parts by mass of a chain transfer agent and 0.2 to 5 parts by mass of a polyfunctional monomer with respect to 100 parts by mass of the ethylenically unsaturated monomer. The laminate according to claim 1, which is obtained by polymerizing a mixed monomer containing   The laminate according to claim 1 or 2, wherein the resin layer (B) is formed by applying an emulsion containing the acrylic resin (x) and drying.   The laminate according to claim 3, wherein the emulsion is a white enamel paint further containing a white pigment.   The resin encapsulating sheet (A) is selected from the group consisting of an ethylene-vinyl acetate copolymer, an ethylene-aliphatic unsaturated carboxylic acid copolymer, an ethylene-aliphatic unsaturated carboxylic acid ester copolymer, and a polyolefin resin. The laminate according to any one of claims 1 to 4, comprising at least one selected resin.   The laminate as described in any one of Claims 1-5 whose gel fraction of the said resin sealing sheet (A) is 0.1-65 mass%.   The laminate according to any one of claims 1 to 6, wherein the resin sealing sheet (A) has a crosslinked structure.   The laminate according to claim 7, wherein the crosslinked structure is formed by ionizing radiation irradiation.   The laminate according to any one of claims 1 to 8, wherein the resin sealing sheet (A) contains an adhesive resin (excluding a silane coupling agent).   The laminate according to any one of claims 1 to 9, wherein the protective sheet (C) contains a polyester resin or a fluorine resin. The water vapor permeability of the protective sheet (C) measured under the conditions of 40 ° C and 90% RH is 2.0 g / m ² / day or less, and the lamination according to any one of claims 1 to 10. object. The protective sheet (C) includes a vapor deposition layer and / or a water vapor barrier layer,
The vapor deposition layer is a layer containing at least one selected from the group consisting of alumina, silica, alumina-silica, inorganic particles, and inorganic oxides,
The laminate according to any one of claims 1 to 11, wherein the water vapor barrier layer is a layer containing at least one selected from the group consisting of a coating layer, an aluminum foil, and a PET film.   The laminate according to any one of claims 1 to 12, wherein the resin sealing sheet (A), the resin layer (B), and the protective sheet (C) are laminated by a dry lamination method.   The solar cell module which used the laminated body as described in any one of Claims 1-13 as a protection member for solar cells.