JPWO2018180261A1 - LAMINATE, MANUFACTURING METHOD THEREOF, AND SOLAR CELL MODULE - Google Patents

Abstract

A laminate having a polymer layer containing a compound having an oxazoline structure and a hard coat layer containing a siloxane resin on one surface of the substrate, a method for producing the laminate, and a solar cell module comprising the laminate.

Description

  The present disclosure relates to a laminate, a manufacturing method thereof, and a solar cell module.

Conventionally, the use of a laminate using a resin as a protective sheet for protecting members has been studied.
For example, the technique regarding using a laminated body as a protection sheet for solar cells which is one member of a solar cell module is known.

  Japanese Patent Application Laid-Open No. 2012-204675 discloses a back sheet for a solar cell in which a solar cell element is placed in contact with the sealing material of a battery-side substrate sealed with a sealing material, and a polyester film base material And at least one polymer layer provided on the polyester film substrate, the polyester film substrate has a terminal carboxyl group concentration of 1 eq / ton or more and 15 eq / ton or less, and differential scanning calorimetry A polyester film base having a minute endothermic peak temperature Tmeta (° C.) determined by the following is 220 ° C. or lower, and the average elongation retention after standing for 72 hours at a temperature of 125 ° C. and a relative humidity of 100% RH is 10% or higher. And at least one of the polymer layers contains at least a fluorine-based polymer and has a carbodiimide compound and an organic polymer. At least one crosslinked structure derived from the crosslinking agent selected from oxazoline compound, a back sheet for solar cell is described a and polymer layer formed by coating.

  JP 2012-131214 A describes a protective film having an ultraviolet shielding layer containing a specific ultraviolet absorber and a weather-resistant binder and a hard coat layer on one surface of a base film.

  JP-A-2006-195165 includes a base film, a polymer A having an ultraviolet-absorbing partial structure, and a binder polymer B, and the polymer A having the ultraviolet-absorbing partial structure and the binder polymer B are of the same type. The transparent sheet for solar cells which has the 1st polymer layer arrange | positioned on one side of the said base film which has the following structural unit is described.

  JP 2013-58746 A discloses a first polymer layer containing at least one binder polymer selected from a fluoropolymer and a silicone polymer on a polymer substrate, and the polymer of the first polymer layer. At least one binder polymer selected from a fluoropolymer and a silicone polymer provided on the substrate side, and a structural part derived from a crosslinking agent having an oxazoline group that crosslinks the binder polymer, and for the binder polymer A solar cell polymer sheet is described that has a second polymer layer in which the equivalent [meq / g] of the oxazoline group is more than 0 and less than 1.

Japanese Patent Laid-Open No. 2006-261189 has a water vapor shielding layer on at least one side of a polyester film having ultraviolet absorptivity, and at least one outermost layer has an easy-adhesion layer having an oxazoline group-containing polymer as a crosslinking agent. A solar cell surface protective film is described which is a laminated film, wherein the laminated film has a water vapor shielding performance of less than 0.3 g / m ² · day.

When the laminate is used as a protective sheet for a member, for example, it is known to use a laminate having a hard coat layer having a pencil hardness of B or more in order to improve scratch resistance against external forces such as scratching and scratching. . In order to achieve the pencil hardness, a siloxane resin may be used in the hard coat layer.
By including the structural unit represented by Formula S1 and the structural unit represented by Formula S2, a hard coat having superior hardness than that described in JP2013-58746A or JP2006-261189A Easy to obtain layer. However, in the hard coat layer containing the structural unit represented by the formula S1 and the structural unit represented by the formula S2, the condensation of the uncondensed part proceeds by UV irradiation or the dissociation / recombination of the siloxane bond occurs. It is considered that cracking occurs when a strain (stress) is generated in the hard coat layer and a volume change accompanying the elimination of the strain occurs.
By further containing a compound having an oxazoline structure in the polymer layer, adhesion between the polymer layer and the hard coat layer is improved. When the adhesive strength with the polymer layer is large, the volume change accompanying the strain elimination of the hard coat layer is limited, so that the crack of the hard coat layer is suppressed.

A problem to be solved by an embodiment according to the present disclosure is to provide a laminate having a hard coat layer excellent in hardness and suppressed cracking after irradiation with ultraviolet rays, or a solar cell module including the laminate.
Moreover, the subject which another embodiment which concerns on this indication solves is providing the manufacturing method of the laminated body which is excellent in hardness and has the hard-coat layer by which the crack after the ultraviolet irradiation was suppressed.

Specific means for solving the problems include the following aspects.
<1> On one surface of the substrate, a polymer layer containing a compound having an oxazoline structure, and a hard coat layer containing a siloxane resin,
The said siloxane resin contains the structural unit represented by following formula S1, and the structural unit represented by following formula S2.
[* -SiO _3/2 ] Formula S1
[SiO _4/2 ] Formula S2
In formula S1, * represents a binding site with another structure. However, the Si atom in Formula S1 is not directly bonded to the O atom at the bonding site.
<2> The above <1>, wherein the total amount of the oxazoline structure and the structure derived from the oxazoline structure contained in the polymer layer is 3.7% by mass to 22.1% by mass with respect to the total mass of the polymer layer. Laminated body.
<3> The laminate according to <2>, wherein the binder polymer is resin particles dispersed in a coating liquid for forming a polymer layer.
<4> In the above siloxane resin, the molar amount of Si atoms in the structural unit represented by Formula S1 is 1.0 to 7.5 times the molar amount of Si atoms in the structural unit represented by Formula S2. The laminate according to any one of <1> to <3>, which is
<5> In the siloxane resin, the molar amount of Si atoms in the structural unit represented by Formula S1 is 1.5 to 4.5 times the molar amount of Si atoms in the structural unit represented by Formula S2. The laminate according to any one of the above items <1> to <4>, which is doubled.
<6> The laminate according to any one of <1> to <5>, wherein the polymer layer contains an ultraviolet absorbing compound.
<7> The laminate according to <6>, wherein the ultraviolet absorbing compound includes a compound having a triazine structure.
<8> The laminate according to the above <6> or <7>, wherein the ultraviolet absorbing compound is composite particles containing an acrylic resin and an ultraviolet absorber.
<9> Five measured values in the case where five thin film slices were prepared by dividing the polymer layer into five at equal intervals in the thickness direction, and the transmittance at a wavelength of 325 nm was measured for each of the five thin film slices. The laminate according to any one of <6> to <8>, wherein the difference between the maximum value and the minimum value is 30% or less of the maximum value.
<10> The laminate according to any one of <1> to <9>, wherein the hard coat layer includes silica particles.
<11> The laminate according to any one of <1> to <10>, wherein the hard coat layer has a thickness of 0.1 μm to 5 μm.
<12> The laminate according to any one of <1> to <11>, wherein the base material is polyester.
<13> On at least one surface of the substrate,
A polymer layer comprising a binder polymer;
A hard coat layer disposed on the surface of the polymer layer and containing a siloxane resin,
After irradiating a metal halide lamp having an intensity of 90 mW / cm ^{2 at} a wavelength of 300 nm to 400 nm at a temperature of 63 ° C. and a relative humidity of 50% for 500 hours, the hard coat layer is not cracked,
As a result of performing a cross-cut adhesion test by the method described in JISK5600-5-6,
A laminate in which the area of the peeled portion is within 20%.
<14> The laminate according to any one of <1> to <13>, wherein the laminate is a solar cell protective sheet.
<15> An element structure including a solar cell element and a sealing material that seals the solar cell element;
The laminate according to any one of the above <1> to <14>, which is disposed on the side on which sunlight is incident on the element structure portion,
A solar cell backsheet disposed on the side opposite to the side on which sunlight is incident on the element structure;
A solar cell module.
<16> a step of preparing a substrate;
Preparing a coating solution for forming a polymer layer containing a binder polymer and a compound having an oxazoline structure;
Preparing a coating liquid for forming a hard coat layer containing a hydrolyzate of trifunctional alkoxysilane and a hydrolyzate of tetrafunctional alkoxysilane;
A step of applying a polymer layer-forming coating solution on one side of the substrate and drying to form a polymer layer; and
On the surface of the polymer layer, a coating liquid for forming a hard coat layer is applied and dried to contain a structural unit represented by the following formula S1 and a siloxane structure containing a structural unit represented by the following formula S2. Forming a hard coat layer. A method for manufacturing a laminate.
[* -SiO _3/2 ] Formula S1
[SiO _4/2 ] Formula S2
In formula S1, * represents a binding site with another structure. However, the Si atom in Formula S1 is not directly bonded to the O atom at the bonding site.
<17> The above <16>, wherein the total amount of the oxazoline structure and the structure derived from the oxazoline structure contained in the polymer layer is 3.7% by mass to 22.1% by mass with respect to the total mass of the polymer layer. The manufacturing method of the laminated body.

According to the embodiment according to the present disclosure, it is possible to provide a laminate having a hard coat layer excellent in hardness and suppressed cracking after irradiation with ultraviolet rays, or a solar cell module including the laminate.
Moreover, according to another embodiment which concerns on this indication, the manufacturing method of the laminated body which is excellent in hardness and has the hard-coat layer by which the crack after irradiation of an ultraviolet-ray was suppressed can be provided.

It is a schematic sectional drawing which shows an example of a solar cell module provided with the laminated body which concerns on this indication.

In the present disclosure, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In the present disclosure, the amount of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. To do.
In the present disclosure, the term “process” is included in the term as long as the intended purpose of the process is achieved, even when the process is not clearly distinguished from other processes.
In the present disclosure, “(meth) acryl” means at least one of acryl and methacryl, and “(meth) acrylate” means at least one of acrylate and methacrylate.
In the present disclosure, the “solid content” refers to all components except the solvent.
In the present disclosure, the “front sheet for solar cell” refers to a sheet disposed on the side on which sunlight is incident as viewed from the solar cell element in the solar cell module.
In the present disclosure, the “back sheet for solar cell” refers to a sheet disposed on the side opposite to the side on which sunlight is incident as viewed from the solar cell element in the solar cell module.
In the present disclosure, the “protective sheet for solar cell” refers to a concept including both the front sheet for solar cell and the back sheet for solar cell in the solar cell module.
In the present disclosure, a combination of preferred embodiments is a more preferred embodiment.

(Laminate)
A first aspect of the laminate according to the present disclosure has a polymer layer containing a compound having an oxazoline structure on one surface of a substrate and a hard coat layer containing a siloxane resin, and the siloxane resin is A structural unit represented by the following formula S1 and a structural unit represented by the following formula S2 are included.
[* -SiO _3/2 ] Formula S1
[SiO _4/2 ] Formula S2
In formula S1, * represents a binding site with another structure. However, the Si atom in Formula S1 is not directly bonded to the O atom at the bonding site.
In a second aspect of the laminate according to the present disclosure, a polymer layer containing a binder polymer is disposed on at least one surface of the base material, and a hard coat layer is disposed on the surface of the polymer layer and contains a siloxane resin. The method according to JISK5600-5-6, wherein the hard coat layer is not cracked after being irradiated with a metal halide lamp having an intensity of 90 mW / cm ^{2 at} a wavelength of 300 nm to 400 nm at 63 ° C. and a relative humidity of 50% for 500 hours. As a result of the cross-cut adhesion test, the peeled area is within 20%.
Hereinafter, the laminate according to the first embodiment is referred to as a first laminate, and the laminate according to the second embodiment is referred to as a second laminate.
The first laminated body or the second laminated body according to the present disclosure includes other layers (for example, an undercoat layer described later, a third layer described later, a fourth layer described later, and other compounds having an oxazoline structure) as necessary. A polymer layer that does not contain).

(First aspect of laminate)
Hereinafter, first, the first laminate according to the present disclosure will be described.
The hard coat layer in the first laminate according to the present disclosure is excellent in hardness, and cracking after irradiation with ultraviolet rays is suppressed.
The reason why such an effect is achieved is presumed as follows. However, the first laminate according to the present disclosure is not limited for the following reasons.

In the 1st laminated body which has the hard-coat layer containing the conventional siloxane resin, it is thought that the reactive group derived from the raw material used for manufacture of siloxane resin, such as an uncrosslinked silanol group, remains. When the hard coat layer is irradiated with light containing ultraviolet rays (for example, sunlight), it is considered that heat is generated in the hard coat layer and the crosslinking reaction of the reactive group proceeds. When the siloxane resin includes a structural unit represented by the above formula S1 and a structural unit represented by the above formula S2, the internal structure of the resin in the hard coat layer is caused by the crosslinking reaction. It has been found that cracking of the hard coat layer occurs due to the change.
The cause of the first laminate according to the present disclosure containing the oxazoline structure is unknown, but cracking of the hard coat layer due to ultraviolet irradiation is suppressed, and the adhesion between the hard coat layer and the polymer layer is further suppressed. Will also improve.

Next, an example of a solar cell module including the first laminate according to the present disclosure will be described with reference to FIG.
The 1st laminated body which concerns on this indication can be used suitably as a protection sheet for solar cells, and is used suitably especially as a front sheet for solar cells.
However, the 1st laminated body and solar cell module which concern on this indication are not limited to the following examples.

FIG. 1 is a schematic cross-sectional view illustrating an example of a solar cell module including the first stacked body according to the present disclosure.
The solar cell module shown in FIG. 1 is also an example of a solar cell module according to the present disclosure which will be described later.

  As shown in FIG. 1, the solar cell module 100 according to this example includes a solar cell element 32 and a sealing material 34 (for example, an ethylene-vinyl acetate copolymer (EVA)) that seals the solar cell element 32. The element structure 36 including the sealing material), the solar cell front sheet 20 disposed on the side where the sunlight 50 is incident on the element structure 36, and the sunlight 50 on the element structure 36. A solar cell backsheet 40 disposed on the side opposite to the incident side.

The solar cell front sheet 20 is an example of a first laminate according to the present disclosure.
The solar cell front sheet 20 is disposed on a base material represented by a polyester film (base material film 10) and one surface of the base film 10 (specifically, the surface on which sunlight 50 is incident). The first layer 11 and the second layer 12 disposed on the surface of the first layer.
The first layer is a polymer layer in the first laminate according to the present disclosure. Hereinafter, the polymer layer used in the present disclosure is also referred to as “first layer”.
The second layer is a hard coat layer in the first laminate according to the present disclosure. Hereinafter, the hard coat layer used in the present disclosure is also referred to as a “second layer”.

The solar cell front sheet 20 is further provided with a third layer 13 and a fourth layer 14 in this order as a back layer on the side opposite to the first layer 11 and the second layer 12 side when viewed from the base film 10. Prepare. The third layer 13 and the fourth layer 14 have a function of an easy adhesion layer for facilitating adhesion to the element structure portion 36.
However, the third layer 13 and the fourth layer 14 are not essential, and at least one of the third layer 13 and the fourth layer 14 may be omitted.
An undercoat layer may be provided on at least one of the surface on the first layer 11 side and the surface on the third layer 13 side of the base film 10. That is, the base film 10 may be a base film with an undercoat layer to be described later.

The solar cell module 100 may include other members other than the members described above.
Examples of the other members include an adhesive layer disposed between the members, a terminal box disposed on the side opposite to the element structure portion 36 with respect to the solar cell backsheet 40, and the like.

The solar cell front sheet 20 is a member into which sunlight 50 is directly incident and a member exposed to wind and rain.
Therefore, the solar cell front sheet 20 is required to have high weather resistance (for example, durability against wet heat environment and ultraviolet irradiation).
In this regard, in the solar cell front sheet 20, by having a polymer layer containing a compound having an oxazoline structure and a hard coat layer containing a siloxane structure on one surface of the substrate, the hardness of the hard coat layer can be increased. It is excellent and it is thought that the crack of the hard coat layer after ultraviolet irradiation is suppressed.

  In the present disclosure, of the two surfaces of the substrate, the surface on which the polymer layer (first layer) and the hard coat layer (second layer) are formed may be referred to as a “front surface”. On the other hand, the surface on the opposite side (the surface on which the third layer and the fourth layer are formed if necessary) may be referred to as a “back surface”.

  Hereinafter, each element of the first laminate according to the present disclosure will be described.

<Polymer layer (first layer)>
The first laminate according to the present disclosure contains a polymer layer containing a compound having an oxazoline structure. Here, from the viewpoint of adhesion between layers in the laminate after the ultraviolet irradiation, the polymer layer containing the compound having an oxazoline structure may be a polymer layer composed of a plurality of layers having different contents of the compound having an oxazoline structure. .
In the present disclosure, the oxazoline structure refers to a structure represented by the following formula A.

In Formula A, R ^{O1 to} R ^O4 each independently represent a hydrogen atom or an alkyl group, and are preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. It is more preferable that

Further, the compound having an oxazoline structure is preferably a polymer having a plurality of structures represented by the above formula A, and more preferably a polymer having a structural unit containing a structure represented by the above formula A.
Although it does not specifically limit as a polymer principal chain, It is preferable that it is a molecular chain formed with a (meth) acrylic acid ester compound.
The weight average molecular weight of the polymer having a plurality of structures represented by Formula A is preferably 20,000 to 1,000,000.
In the present disclosure, the weight average molecular weight refers to a value measured by gel permeation chromatography (GPC).
Measurement by GPC uses HLC (registered trademark) -8020 GPC (Tosoh Corp.) as a measuring device, and TSKgel (Registered Trademark) Super Multipore HZ-H (4.6 mm ID × 15 cm, Tosoh Corp.) as a column. Are used, and THF (tetrahydrofuran) is used as an eluent. The measurement conditions are a sample concentration of 0.45 mass%, a flow rate of 0.35 mL / min, a sample injection amount of 10 μL, a measurement temperature of 40 ° C., and a differential refractive index (RI) detector. be able to.
The calibration curve is “Standard sample TSK standard, polystyrene” of Tosoh Corporation: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000”, “A -2500 "," A-1000 ", and" n-propylbenzene ".

  Examples of the compound having an oxazoline structure include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline. 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2,2′-bis- (2-oxazoline), 2,2′-methylene-bis- ( 2-oxazoline), 2,2′-ethylene-bis- (2-oxazoline), 2,2′-trimethylene-bis- (2-oxazoline), 2,2′-tetramethylene-bis- (2-oxazoline) 2,2′-hexamethylene-bis- (2-oxazoline), 2,2′-octamethylene-bis- (2-oxazoline), 2,2′-ethylene Bis- (4,4′-dimethyl-2-oxazoline), 2,2′-p-phenylene-bis- (2-oxazoline), 2,2′-m-phenylene-bis- (2-oxazoline), 2 , 2'-m-phenylene-bis- (4,4'-dimethyl-2-oxazoline), bis- (2-oxazolinylcyclohexane) sulfide, bis- (2-oxazolinyl norbornane) sulfide, and the like. . Furthermore, the homopolymer or copolymer of these compounds is also mentioned.

In forming a polymer layer containing a compound having an oxazoline structure, a commercial product of a diluted solution of an oxazoline-based crosslinking agent may be used.
As a commercial item of the dilution liquid of an oxazoline type crosslinking agent, for example, Epocross (registered trademark) K-2010E, K-2020E, K-2030E, WS-500, WS-700 [all manufactured by Nippon Shokubai Chemical Co., Ltd.] ] Etc. are mentioned.

In addition, in the compound having an oxazoline structure, a part of the oxazoline structure may be opened to form a crosslinked structure. That is, the polymer component contained in the polymer layer (for example, a binder polymer described later, a polymer contained in the ultraviolet absorbing compound, etc.) may be crosslinked by a ring-opened oxazoline structure. However, the compound having an oxazoline structure shall have at least one oxazoline structure which is not ring-opened. The content of the oxazoline structure that is not ring-opened is preferably 0.1% by mass or more based on the total mass of the polymer layer. When the polymer layer is a polymer layer composed of a plurality of layers having different contents of the compound having an oxazoline structure, among the plurality of layers, the compound having the oxazoline structure of the layer in contact with the hard coat layer in the present disclosure The content is preferably controlled, and the content is preferably 0.1% by mass or more based on the total mass of the layer in contact with the hard coat layer.
In the polymer layer in the present disclosure, the total amount of the oxazoline structure and the structure derived from the oxazoline structure is preferably 2.5% by mass to 22.7% by mass with respect to the total mass of the polymer layer, and is 3.7% by mass. It is more preferably ˜22.1% by mass, and further preferably 3.7% by mass to 16.7% by mass.
When the polymer layer is a polymer layer composed of a plurality of layers having different contents of the compound having an oxazoline structure, the oxazoline structure and the oxazoline structure of the layer in contact with the hard coat layer in the present disclosure among the plurality of layers described above The total amount of the structure is preferably controlled, and the total amount is preferably 2.5% by mass to 22.7% by mass with respect to the total mass of the layer in contact with the hard coat layer in the present disclosure. More preferably, it is 0.7 mass%-22.1 mass%, and it is still more preferable that it is 3.7 mass%-16.7 mass%.
When the polymer layer is a polymer layer composed of a plurality of layers, the total amount of the oxazoline structure and the structure derived from the oxazoline structure in the outermost layer (layer in contact with the hard coat layer) is preferably within the above range.
Confirmation that the compound having an oxazoline structure is contained in the polymer layer and the measurement of the content of the oxazoline structure in the polymer layer are within a range of 20% in the film thickness direction from the surface in contact with the hard coat layer of the polymer layer. A portion is scraped off, 10 mg is sampled, this is analyzed by ¹ H-NMR, and it can be determined from the absorption peak intensity derived from the oxazoline structure and the absorption peak intensity derived from other binders.
The structure derived from the oxazoline structure refers to a structure in which the oxazoline structure is opened without being crosslinked, and a structure in which the oxazoline structure is subjected to a crosslinking reaction to form an amide ester. In the case where the oxazoline structure is a structure obtained by amide esterification by a crosslinking reaction, the content of the oxazoline structure is converted only from the structure part where the oxazoline structure of Formula A is opened, and the ester structure part is not included. Further, the structure derived from the oxazoline structure is a structure derived from the oxazoline structure having a substituent represented by the above R ^{O1 to} R ^O4 , and the substituent derived from the oxazoline structure is also represented by the above R ^{O1 to} R ^O4. Is included, the content of the structure derived from the oxazoline structure includes the mass of the substituent.

[Binder polymer]
The polymer layer preferably contains a binder polymer.
The binder polymer is not particularly limited, but is preferably at least one selected from the group consisting of acrylic resin, polyester, polyurethane, polyolefin, siloxane resin and fluoropolymer, and selected from the group consisting of acrylic resin, polyester, polyurethane and polyolefin. At least one selected from the above is more preferable, and acrylic resin is still more preferable.

In the present disclosure, the “acrylic resin” is a group consisting of a structural unit derived from acrylic acid, a structural unit derived from methacrylic acid, a structural unit derived from an acrylate compound, and a structural unit derived from a methacrylic ester compound. It refers to a polymer comprising at least one selected structural unit.
The concept of acrylic resin includes, for example, a homopolymer of acrylic acid, a homopolymer of methacrylic acid, a homopolymer of acrylic acid ester, a homopolymer of methacrylic acid ester, and a copolymer of acrylic acid and other monomers , A copolymer of methacrylic acid and other monomers, a copolymer of acrylic acid ester and other monomers, a copolymer of methacrylic acid ester and other monomers, and the like.

Examples of the monomer for forming the acrylic resin include (meth) acrylic acid and (meth) acrylic acid ester.
More specifically, as a monomer for forming an acrylic resin, for example, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, acetoxyethyl (meth) acrylate, phenyl (meth) acrylate 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, diethylene Glycol monomethyl ether (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, diethylene glycol monophenyl ether (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, triethylene glycol monoethyl ether (meth) acrylate, dipropylene glycol Monomethyl ether (meth) acrylate, polyethylene glycol monomethyl ether (meth) acrylate, polypropylene glycol monomethyl ether (meth) acrylate, monomethyl ether (meth) acrylate of a copolymer of ethylene glycol and propylene glycol, N, N-dimethylaminoethyl (Meth) acrylate, N, N-diethylaminoethyl (meth) Acrylate, N, N-dimethylaminopropyl (meth) acrylate.
Here, (meth) acrylic acid means acrylic acid or methacrylic acid, and (meth) acrylate means methacrylate or acrylate.

When the acrylic resin is a copolymer of two or more monomers, a monomer other than the monomer for forming the acrylic resin (other monomers) may be used as a copolymerization component.
Other monomers include nitrogen-containing monomers such as (meth) acrylamide, diacetone acrylamide, N-methylol acrylamide, and (meth) acrylonitrile; monomers having a styrene skeleton such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene; Monomers having a siloxane structure described later; vinyl esters such as vinyl propionate; phosphorus-containing vinyl monomers; vinyl halides such as vinyl chloride and vinylidene chloride; conjugated dienes such as butadiene;

The acrylic resin contained in the polymer layer is preferably an acrylic resin having a siloxane structure.
Thereby, it is thought that the adhesiveness of a polymer layer and the hard-coat layer containing a siloxane resin improves more, and the crack of the hard-coat layer by ultraviolet irradiation is further suppressed.

An acrylic resin having a siloxane structure (hereinafter sometimes referred to as “siloxane-containing acrylic resin” or “siloxane-containing acrylic”) is a copolymer of a monomer for forming an acrylic resin and a monomer having a siloxane structure. It is preferable that
The “siloxane structure” in the “acrylic resin having a siloxane structure” and the “monomer having a siloxane structure” preferably includes a siloxane structural unit represented by the following general formula (1).

In general formula (1), R ¹ and R ² each independently represents a hydrogen atom, a halogen atom, or a monovalent organic group. Here, R ¹ and R ² may be the same or different, and a plurality of R ¹ and R ² may be the same or different from each other. n represents an integer of 1 or more.

Examples of the halogen atom represented by R ¹ and R ² include a fluorine atom, a chlorine atom, and an iodine atom.

The “monovalent organic group” represented by R ¹ and R ² is a group that can be covalently bonded to a Si atom.
Examples of the monovalent organic group include an alkyl group (eg, methyl group, ethyl group, etc.), an aryl group (eg, phenyl group, etc.), an aralkyl group (eg, benzyl group, phenylethyl group, etc.), an alkoxy group ( Examples: methoxy group, ethoxy group, propoxy group, etc.), aryloxy group (eg, phenoxy group etc.), mercapto group, amino group (eg: amino group, diethylamino group etc.), amide group and the like.
These groups may have a substituent.

R ¹ and R ² are each independently a hydrogen atom, a chlorine atom, a bromine atom, an unsubstituted or substituted alkyl group having 1 to 4 carbon atoms in terms of adhesiveness to an adjacent material such as a substrate. (Especially methyl and ethyl groups), unsubstituted or substituted phenyl groups, unsubstituted or substituted alkoxy groups, mercapto groups, unsubstituted amino groups, or amide groups are preferred, unsubstituted or substituted An alkoxy group (preferably an alkoxy group having 1 to 4 carbon atoms) is more preferable.

  n is preferably 1 to 5000, and more preferably 1 to 1000.

The ratio of the siloxane structural unit represented by the general formula (1) in the siloxane-containing acrylic resin is preferably 15% by mass to 85% by mass and is in the range of 20% by mass to 80% by mass with respect to the total mass of the siloxane-containing acrylic resin. Is more preferable.
When the ratio of the structural unit represented by the general formula (1) is 15% by mass or more, the adhesion with the hard coat layer is further improved, and cracking of the hard coat layer due to ultraviolet irradiation is further suppressed.
When the ratio of the structural unit represented by the general formula (1) is 85% by mass or less, when the polymer layer is formed using the polymer layer forming coating solution, the stability of the polymer layer forming coating solution is more stable. improves.

A particularly preferred embodiment of the siloxane-containing acrylic resin is
The ratio of the siloxane structural unit represented by the general formula (1) is 15% by mass to 85% by mass (preferably 20% by mass to 80% by mass) with respect to the total mass of the siloxane-containing acrylic resin, and
The proportion of structural units derived from acrylic acid, methacrylic acid, acrylic ester, or methacrylic ester is 85% by mass to 15% by mass (preferably 80% by mass to 20% by mass) with respect to the total mass of the siloxane-containing acrylic resin. ).

As a method for producing a siloxane-containing acrylic resin,
(I) a method of reacting a homopolymer or copolymer of a monomer forming an acrylic resin with a polysiloxane having a structural unit represented by the general formula (1),
(Ii) Silane having a structural unit represented by the general formula (1) in which R ¹ and / or R ² is a hydrolyzable group in the presence of a homopolymer or copolymer of a monomer that forms an acrylic resin. A method of hydrolytic condensation of a compound;
Etc. can be used.
Examples of the silane compound used in the method (ii) include various silane compounds, and alkoxysilane is particularly preferable.

In forming a polymer layer containing an acrylic resin, a commercial product of an acrylic resin dispersion may be used.
Examples of commercially available acrylic resin dispersions include AS-563A (manufactured by Daicel Finechem Co., Ltd.), Jurimer (registered trademark) ET-410, SEK-301 (both manufactured by Nippon Pure Chemical Industries, Ltd.), Etc.
Commercially available dispersions of siloxane-containing acrylic resins include, for example, SERANATE (registered trademark) series manufactured by DIC Corporation (for example, SERATE (registered trademark) WSA1070, WSA1060, etc.), and H7600 manufactured by Asahi Kasei Chemicals Corporation. Series (H7650, H7630, H7620, etc.), inorganic / acryl composite emulsion manufactured by JSR Corporation, Saimak (registered trademark) series (GS-30, etc.) manufactured by Toagosei Co., Ltd., and the like.
Among the above, the SERATE (registered trademark) series manufactured by DIC Corporation, the inorganic / acrylic composite emulsion manufactured by JSR Corporation, or the SIMAC (registered trademark) series manufactured by Toagosei Co., Ltd. is preferable.

As a binder polymer in a polymer layer, you may contain other polymers other than an acrylic resin. Examples of other polymers include polyester, polyurethane, polyolefin, siloxane resin, and fluoropolymer.
30 mass% or more is preferable with respect to the quantity of all the polymer components in a polymer layer, and, as for content of the acrylic resin in a polymer layer, 60 mass% or more is more preferable.

From the viewpoint of the hardness of the polymer layer, the content of the acrylic resin is more preferably 50% by mass to 95% by mass, more preferably 55% by mass to 90% by mass, and more preferably 55% by mass to 85% with respect to the solid content of the polymer layer. % By mass is more preferable, and 60% by mass to 80% by mass is particularly preferable.
The preferable range of the content of the whole polymer in the polymer layer is the same as the preferable range of the content of the acrylic resin.

The content of the acrylic resins, from the viewpoint of the hardness of the polymer layer, is preferably 15 g / ^{m 2} or less than the 0.2 g / ^{m 2,} a 0.5g / ^{m 2} ~10.0g / m 2 it is more ^preferable, and particularly preferably ^{1.0g / m 2 ~8.0g / m 2} .
The preferable range of the content of the whole polymer in the polymer layer is the same as the preferable range of the content of the acrylic resin.

  As described above, the binder polymer in the polymer layer may contain polyesters, polyurethanes, polyolefins, siloxane resins, fluoropolymers, etc. as other polymers other than acrylic resins. When a polymer layer contains another polymer, the other polymer contained may be only 1 type, or 2 or more types.

-Polyester-
As polyester, for example, polyethylene terephthalate (PET), polyethylene-2,6-naphthalate (PEN) and the like are preferable.
As a commercially available polyester dispersion, for example, Vylonal (registered trademark) MD-1245 (manufactured by Toyobo Co., Ltd.) can be preferably used.

-Polyurethane-
As the polyurethane, for example, a carbonate-based urethane resin is preferable.
As a commercially available polyurethane dispersion, for example, Superflex (registered trademark) 460 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) can be preferably used.

-Polyolefin-
As the polyolefin, for example, a modified polyolefin copolymer is preferable.
Commercially available polyolefin dispersions include, for example, Arrow Base (registered trademark) SE-1013N, SD-1010, TC-4010, TD-4010 (both manufactured by Unitika Ltd.), Hitech S3148, S3121, S8512 (both Toho Chemical Co., Ltd.), Chemipearl (registered trademark) S-120, S-75N, V100, EV210H (both manufactured by Mitsui Chemicals, Inc.) and the like. Among them, Arrowbase (registered trademark) SE-1013N, manufactured by Unitika Ltd., which is a terpolymer of low-density polyethylene, acrylic acid ester, and maleic anhydride is preferable.
In addition, acid-modified polyolefins described in paragraphs 0022 to 0034 of JP-A-2014-76632 can also be preferably used.

-Siloxane resin-
The siloxane resin is a polymer having a siloxane structural unit in the molecular chain, and is not particularly limited.
The siloxane resin may be a homopolymer of a compound having a siloxane structural unit, and includes a siloxane structural unit and another structural unit (however, a structural unit derived from acrylic acid or methacrylic acid is not included) It may be a copolymer containing The other structural unit copolymerized with the siloxane structural unit is a non-siloxane structural unit. As the siloxane structural unit, the siloxane structural unit represented by the above general formula (1) is preferable.

  As a copolymer in the siloxane resin, a siloxane compound (including polysiloxane) and a siloxane represented by the above general formula (1) are copolymerized with a compound selected from a non-siloxane monomer or a non-siloxane polymer. A block copolymer having a structural unit and a non-siloxane structural unit is preferred. In this case, the siloxane compound and the non-siloxane monomer or non-siloxane polymer to be copolymerized may be one kind alone or two or more kinds.

  The non-siloxane structural unit copolymerized with the siloxane structural unit (derived from the non-siloxane monomer or non-siloxane polymer) is not particularly limited except that it does not have a siloxane structure, and is derived from any polymer. Any of the polymer segments may be used. Examples of polymers (precursor polymers) that are polymer segment precursors include vinyl polymers (not including homopolymers or copolymers of monomers for forming the acrylic resin described above), polyester polymers, and the like. And various polymers such as polyurethane-based polymers. Among these, vinyl polymers and polyurethane polymers are preferable, and vinyl polymers are particularly preferable because they are easy to prepare and have excellent hydrolysis resistance.

Typical examples of the vinyl polymer include various polymers such as a carboxylic acid vinyl ester polymer, an aromatic vinyl polymer, and a fluoroolefin polymer.
In addition, the polymer which comprises a non-siloxane type structural unit may be single 1 type, and 2 or more types of combined use may be sufficient as it.

  The precursor polymer of the siloxane resin can be produced and obtained by using the method described in paragraphs 0021 to 0078 of JP-A-2009-52011, for example.

-Fluoropolymer-
The fluoropolymer is not particularly limited as long as it is a resin having a structural unit represented by-(CFX ¹ -CX ² X ³ )-(however, X ¹ , X ² , and X ³ are each independently hydrogen An atom, a fluorine atom, a chlorine atom, or a perfluoroalkyl group having 1 to 3 carbon atoms).
Specific examples of the resin include polytetrafluoroethylene (hereinafter sometimes referred to as PTFE), polyvinyl fluoride (hereinafter sometimes referred to as PVF), and polyvinylidene fluoride (hereinafter referred to as PVDF). ), Polychloroethylene trifluoride (hereinafter sometimes referred to as PCTFE), polytetrafluoropropylene (hereinafter sometimes referred to as HFP), and the like.

The fluoropolymer may be a homopolymer obtained by polymerizing a single monomer, or may be a copolymer obtained by copolymerizing two or more kinds. Examples of copolymerized two or more types include copolymers of tetrafluoroethylene and tetrafluoropropylene (abbreviated as P (TFE / HFP)), copolymers of tetrafluoroethylene and vinylidene fluoride (P (TFE)). / VDF)) and the like.
Further, the fluoropolymer may be a resin obtained by copolymerizing a fluorine-based structural unit represented by-(CFX ¹ -CX ² X ³ )-and other structural units. Examples of these are a copolymer of tetrafluoroethylene and ethylene (hereinafter abbreviated as P (TFE / E)), a copolymer of tetrafluoroethylene and propylene (abbreviated as P (TFE / P)), tetrafluoroethylene and A copolymer of vinyl ether (abbreviated as P (TFE / VE)), a copolymer of tetrafluoroethylene and perfluorovinyl ether (abbreviated as P (TFE / FVE)), a copolymer of chlorotrifluoroethylene and vinyl ether (P (Abbreviated as CTFE / VE)), a copolymer of chlorotrifluoroethylene and perfluorovinyl ether (abbreviated as P (CTFE / FVE)), and the like.

  These fluoropolymers may be used by dissolving in an organic solvent, or may be used by dispersing in water. The latter is preferred because of its low environmental impact. The aqueous dispersions of fluoropolymers are described in, for example, Japanese Patent Application Laid-Open Nos. 2003-231722, 2002-20409, and 9-194538.

[Ultraviolet absorbing compound]
The polymer layer preferably contains at least one ultraviolet absorbing compound.
When the polymer layer is a polymer layer composed of a plurality of layers, at least one layer is preferably a layer containing an ultraviolet absorbing compound from the viewpoint of adhesion after ultraviolet irradiation. Furthermore, the layer other than the outermost layer is more preferably a layer containing an ultraviolet absorbing compound. By setting the layer containing the ultraviolet absorbing compound inside, it is possible to suppress the influence of bleeding out of the ultraviolet absorbent over time, and as a result, it is possible to maintain good adhesion after ultraviolet irradiation. The UV-absorbing compound in the polymer layer has a function of suppressing deterioration of the polymer layer itself, the base material, and the like due to UV rays. In particular, when the first laminate is used as a solar cell front sheet, the solar cell It has a function of improving the weather resistance of the front seat for use.
As an ultraviolet-absorbing compound, although the ultraviolet absorber mentioned later may be included as it is, a polymer having an ultraviolet-absorbing structure is preferable.
Examples of the polymer having an ultraviolet absorbing structure include a polymer containing an ultraviolet absorber and a polymer containing a monomer unit having an ultraviolet absorbing structure.
The total content of the monomer unit containing the UV absorber and the UV absorbing structure ^is preferably ^{0.3g / m 2 ~8.0g / m 2} , 0.3g / m 2 ~5.0g / M ² is more preferable.

-Polymers containing UV absorbers-
The polymer having an ultraviolet absorbing structure is preferably a polymer containing an ultraviolet absorber.
The form of the polymer containing the ultraviolet absorbent is not particularly limited as long as the ultraviolet absorbent is contained, but is preferably in the form of composite particles in which the ultraviolet absorbent is coated with the polymer. In other words, the polymer layer preferably contains at least one composite particle of an ultraviolet absorber and a polymer.

-UV absorber-
In the present disclosure, the ultraviolet absorber is a compound having an ultraviolet absorbing performance and a molecular weight of less than 5,000. The molecular weight refers to the weight average molecular weight measured by the method described above when the ultraviolet absorber has a molecular weight distribution. When there is no molecular weight distribution, the molecular weight is measured using, for example, electrospray ionization mass spectrometry (ESI-MS).
As the ultraviolet absorber, a compound having a maximum absorption wavelength at 380 nm or less is preferable, and a compound having a maximum absorption wavelength at 250 nm to 380 nm (particularly preferably 270 nm to 380 nm) is more preferable.
Examples of ultraviolet absorbers include triazine compounds, benzotriazole compounds, benzophenone compounds, salicylic acid compounds, and the like.
The ultraviolet absorber preferably contains a triazine compound or a benzotriazole compound, and more preferably contains a triazine compound, from the viewpoint of ultraviolet absorption performance.
The total content of the triazine compound and the benzotriazole compound in the ultraviolet absorber is preferably 80% by mass or more based on the total amount of the ultraviolet absorber.
The content of the triazine compound in the ultraviolet absorber is preferably 80% by mass or more based on the total amount of the ultraviolet absorber.

  Examples of the triazine compound include 2- (4-butoxy-2-hydroxyphenyl) -4,6-bis (4-butoxyphenyl) -1,3,5-triazine, 2- (4-butoxy-2-hydroxy Phenyl) -4,6-bis (2,4-dibutoxyphenyl) -1,3,5-triazine, 2,4-bis (4-butoxy-2-hydroxyphenyl) -6- (4-butoxyphenyl) -1,3,5-triazine, 2,4-bis (4-butoxy-2-hydroxyphenyl) -6- (2,4-dibutoxyphenyl) -1,3,5-triazine, 2,4,6 -Tris (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -4,6-bis (2,4-dimethylphenyl)- 1, , 5-triazine, 2- (2,4-dihydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2-hydroxy-4-) Propyloxyphenyl) -6- (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -4,6-bis (4-methylphenyl)- 1,3,5-triazine, 2- (2-hydroxy-4-dodecyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-hydroxy -4-tridecyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-butyloxypropoxy) ) Nyl] -4,6-bis (2,4-dimethyl) -1,3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-octyloxypropyloxy) phenyl] -4, 6-bis (2,4-dimethyl) -1,3,5-triazine, 2- [4- (dodecyloxy / tridecyloxy-2-hydroxypropoxy) -2-hydroxyphenyl] -4,6-bis ( 2,4-Dimethylphenyl) -1,3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-dodecyloxypropoxy) phenyl] -4,6-bis (2,4-dimethyl) Phenyl) -1,3,5-triazine, 2- (2-hydroxy-4-hexyloxy) phenyl-4,6-diphenyl-1,3,5-triazine, 2- (2-hydroxy-4-methoxyphene) Nyl) -4,6-diphenyl-1,3,5-triazine, 2,4,6-tris (2-hydroxy-4- (3-butoxy-2-hydroxypropoxy) phenyl) -1,3,5- Triazine, 2- (2-hydroxyphenyl) -4- (4-methoxyphenyl) -6-phenyl-1,3,5-triazine, 2- {2-hydroxy-4- [3- (2-ethylhexyl-1) -Oxy) -2-hydroxy-propyloxy] phenyl} -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-hydroxy-4- (2-ethylhexyl) Oxy) phenyl-4,6-bis (4-phenyl) phenyl-1,3,5-triazine, and the like.

  Examples of the benzotriazole compound include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-t-butylphenyl) benzotriazole, 2- (2′- Hydroxy-3′-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3′-dodecyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-amylphenyl) benzotriazole, 2- (2'-hydroxy-5 '-(1,1,3,3-tetramethylbutyl) phenyl) benzotriazole, 2- (2'-hydroxy-4' Octyloxyphenyl) benzotriazole, 2- (2′-hydroxy-3 ′-(3,4,5,6-tetrahydrophthalimidylmethyl) -5′-methylbenzyl) phenyl) benzotriazole, 2- (3 ′ -Sec-butyl-5′-t-butyl-2′-hydroxyphenyl) benzotriazole, 2- (3 ′, 5′-bis- (α, α-dimethylbenzyl) -2′-hydroxyphenyl) benzotriazole, 2- (3′-t-butyl-2′-hydroxy-5 ′-(2-octyloxycarbonylethyl) phenyl) -5-chloro-benzotriazole, 2- (3′-t-butyl-5 ′-[ 2- (2-Ethylhexyloxy) -carbonylethyl] -2′-hydroxyphenyl) -5-chloro-benzotriazole, 2- (3′-t-butyl) 2'-hydroxy-5 '-(2-methoxycarbonylethyl) phenyl) -5-chloro-benzotriazole, 2- (3'-t-butyl-2'-hydroxy-5'-(2-methoxycarbonyl) Ethyl) phenyl) benzotriazole, 2- (3′-t-butyl-2′-hydroxy-5 ′-(2-octyloxycarbonylethyl) phenyl) benzotriazole, 2- (3′-t-butyl-5 ′ -[2- (2-ethylhexyloxy) carbonylethyl] -2'-hydroxyphenyl) benzotriazole, 2- (3'-dodecyl-2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (3 ' -T-butyl-2'-hydroxy-5 '-(2-isooctyloxycarbonylethyl) phenylbenzotriazole, 2, '- methylene - bis [4- (1,1,3,3-tetramethylbutyl) -6-benzotriazol-2-yl phenol], and the like.

  Examples of the benzophenone compound include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-decyloxybenzophenone, and 2-hydroxy-4-dodecyl. Oxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4- (2-hydroxy-3-methacryloxypropoxy) benzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-4 -Methoxy-5-sulfobenzophenone trihydrate, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2-hydroxy-4-die Ruamino-2'-hexyloxycarbonylbenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone 1,4-bis (4-benzyloxy-3-hydroxyphenoxy) butane, and the like.

  Examples of the salicylic acid compound include phenyl salicylate, 4-t-butylphenyl salicylate, 4-octylphenyl salicylate, dibenzoylresorcinol, bis (4-t-butylbenzoyl) resorcinol, benzoylresorcinol, 2,4-di-t- Examples include butylphenyl 3,5-di-t-butyl-4-hydroxysalicylate, hexadecyl 3,5-di-t-butyl-4-hydroxysalicylate, and the like.

  As the oxalic acid diamide compound, for example, 4,4′-dioctyloxyoxanilide, 2,2′-dioctyloxy-5,5′-di-t-butyloxanilide, 2,2′-didodecyloxy -5,5'-di-t-butyloxanilide, 2-ethoxy-2'-ethyloxanilide, N, N'-bis (3-dimethylaminopropyl) oxamide, 2-ethoxy-5-t- Examples thereof include butyl-2′-ethyloxanilide, 2-ethoxy-2′-ethyl-5,4′-di-t-butyloxanilide, and the like.

-Composite particles of UV absorber and polymer-
The polymer contained in the composite particle is different from the binder polymer in the polymer layer (first layer) in that it is a component constituting the composite particle.
Examples of the polymer contained in the composite particles include acrylic resin, polyester, polyurethane, polyolefin, siloxane resin, and fluoropolymer, and acrylic resin is preferable.
When the polymer having an ultraviolet absorbing structure is a composite particle of an ultraviolet absorber and an acrylic resin, the long-term weather resistance and transparency of the solar cell module are further improved. The reason for this is considered to be that when the polymer contained in the composite particles is an acrylic resin, the water dispersibility of the composite particles is improved and the polymer particles are dispersed in a nearly uniform state.

  Examples of the monomer for forming the acrylic resin include monomers for forming the acrylic resin in the above-described binder polymer.

The content of the ultraviolet absorber in the composite particles of the ultraviolet absorber and the polymer is preferably 20% by mass to 80% by mass, more preferably 30% by mass to 70% by mass, and more preferably 40% by mass to the total amount of the composite particles. 60% by mass is particularly preferred.
The content of the polymer in the composite particles of the ultraviolet absorber and the polymer is preferably 20% by mass to 80% by mass, more preferably 30% by mass to 70% by mass, and more preferably 40% by mass to 60% by mass with respect to the total amount of the composite particles. % Is particularly preferred.

  The weight average molecular weight of the polymer (for example, acrylic resin) contained in the composite particles of the ultraviolet absorber and the polymer is preferably from 5,000 to 200,000, more preferably from 7,000 to 7,000, from the viewpoint of further improving long-term weather resistance. 150,000 is more preferable, and 10,000 to 100,000 is more preferable.

The median diameter (D50) of the composite particles of the ultraviolet absorber and the polymer is preferably less than 500 nm, more preferably less than 400 nm, and particularly preferably less than 150 nm.
The lower limit of the median diameter is preferably 10 nm or more, and more preferably 20 nm or more.
The median diameter is calculated from the particle size distribution by dynamic light scattering measurement.

[Polymer containing monomer unit having ultraviolet absorbing structure]
The polymer having an ultraviolet absorbing structure may be a polymer including a monomer unit having an ultraviolet absorbing structure.
The monomer unit having an ultraviolet absorbing structure is preferably a monomer unit derived from a polymerizable compound containing at least a part of the structure such as the above-described triazine compound, benzotriazole compound, benzophenone compound, salicylic acid compound, and the like. A monomer unit derived from a polymerizable compound containing at least a part of the structure is more preferable.
The polymer containing a monomer unit having an ultraviolet absorbing structure is preferably an acrylic resin, and an acrylate compound containing at least a part of the structure of the above-mentioned triazine compound, benzotriazole compound, benzophenone compound, salicylic acid compound, etc. An acrylic resin containing a monomer unit derived from is more preferable, and an acrylic resin containing a monomer unit derived from an acrylate compound containing at least part of the structure of the triazine compound is more preferable.
The acrylic resin may be a copolymer further including a monomer unit derived from the same monomer as that for forming the acrylic resin in the composite particle.
The content of the monomer unit having an ultraviolet absorption structure is preferably 10% by mass to 80% by mass, and preferably 30% by mass to 70% by mass with respect to the total mass of the polymer including the monomer unit having an ultraviolet absorption structure. More preferably, it is mass%.

  The weight average molecular weight of the polymer containing a monomer unit having an ultraviolet absorbing structure is preferably 5,000 to 200,000, more preferably 7,000 to 150,000, from the viewpoint of further improving long-term weather resistance. More preferably, it is 10,000 to 100,000.

  In the polymer layer, the ratio of the content of the polymer containing monomer units having an ultraviolet absorption structure to the content of the binder polymer (binder polymer: the polymer containing monomer units having an ultraviolet absorption structure) is based on mass. It is preferable that it is 0.05-0.60. If the said ratio is 0.05 or more, it is excellent in the electric power generation efficiency of a solar cell, and if it is 0.60 or less, it is excellent in the long-term weather resistance.

A commercially available product may be used as the polymer having an ultraviolet absorbing structure.
Examples of commercially available products include Tinuvin (registered trademark) 99-DW, 400-DW, 477-DW, 479-DW (both manufactured by BASF), New Coat (registered trademark) UVA-204W, UVA-101, UVA- 102, UVA-103, UVA-104, Vanaresin (registered trademark) UVA-5080, UVA-5080 (OHV20), UVA-55T, UVA-55MHB, UVA-7075, UVA-7075 (OHV20), UVA-73T (both Shinnakamura Chemical Co., Ltd.) RUVA-93 (Otsuka Chemical Co., Ltd.) and the like.

  The total content of the monomer unit including the ultraviolet absorber and the ultraviolet absorbing structure contained in the polymer layer is 1% by mass or more and 50% by mass or less with respect to the total mass of the polymer component contained in the polymer layer. It is preferably 3% by mass or more and 30% by mass or less.

A preferred embodiment of the first laminate according to the present disclosure is an embodiment in which the ultraviolet absorbing compound includes a compound having a triazine structure.
The term “ultraviolet-absorbing compound contains a compound having a triazine structure” means that the ultraviolet absorber contains the above-mentioned triazine compound, or the above-mentioned ultraviolet-absorbing structure contains the above-mentioned triazine structure.
Moreover, the other preferable aspect of the 1st laminated body which concerns on this indication WHEREIN: The said ultraviolet-absorbing compound is a composite particle of the above-mentioned ultraviolet absorber and acrylic resin. It is more preferable that the ultraviolet absorber contained in the composite particle is a triazine compound.

[Structure derived from crosslinking agent]
The polymer layer may include a structure derived from a crosslinking agent other than the compound having an oxazoline structure from the viewpoints of hardness and durability.
The crosslinking agent may be only one type or two or more types.
Examples of the crosslinking agent include an epoxy crosslinking agent, an isocyanate crosslinking agent, a melamine crosslinking agent, a carbodiimide crosslinking agent, and the like.
Among these, a carbodiimide-based crosslinking agent or an isocyanate-based crosslinking agent is preferable, and an oxazoline-based crosslinking agent is particularly preferable.

In the case of forming a polymer layer containing a structure derived from a crosslinking agent, the addition amount of the crosslinking agent is preferably 20 parts by mass or more and 70 parts by mass or less, more preferably 25 parts per 100 parts by mass of the binder polymer contained in the polymer layer. It is not less than 60 parts by mass.
When the addition amount of the crosslinking agent is 20 parts by mass or more, a sufficient crosslinking effect can be obtained while maintaining the hardness and adhesiveness of the polymer layer.
When the addition amount of the crosslinking agent is 70 parts by mass or less, the storage stability of the coating solution can be kept long, and when it is 60 parts by mass or less, the coated surface state can be improved.

  When the polymer layer includes a structure derived from a crosslinking agent, the content of the structure derived from the crosslinking agent is preferably 10 parts by mass or more and 40 parts by mass or less, more preferably 100 parts by mass with respect to 100 parts by mass of the binder polymer contained in the polymer layer. Is 15 parts by mass or more and 35 parts by mass or less.

(Crosslinking catalyst)
The polymer layer may contain at least one crosslinking catalyst from the viewpoint of promoting a crosslinking reaction between the binder polymer and the crosslinking agent.
As the crosslinking catalyst, a known crosslinking catalyst can be used without any particular limitation, and examples thereof include onium compounds.

[Surfactant]
The polymer layer may contain at least one surfactant.
Examples of the surfactant include known surfactants such as an anionic surfactant and a nonionic surfactant.
When the polymer layer contains a surfactant, the content of the surfactant is preferably 0.01% by mass to 1% by mass, and 0.01% by mass to 0.2% by mass with respect to the solid content of the polymer layer. Is more preferable.

[UV absorption performance]
When the polymer layer contains a UV-absorbing compound, the polymer layer in the present disclosure produces five thin film sections that are divided into five at equal intervals in the thickness direction, and each of the five thin film sections has a wavelength of 325 nm. In the five measured values when the transmittance is measured, the difference between the maximum value and the minimum value is preferably 30% or less of the maximum value, and more preferably 20% or less. The lower limit is not particularly limited and may be 0% or more.
The difference between the maximum value and the minimum value is achieved by dispersing a polymer having an ultraviolet absorbing structure in the polymer layer in a nearly uniform state.
Note that the above-mentioned equal intervals do not have to be completely equal intervals, and may have errors as long as they are within an average value ± 10% of the thicknesses of the five thin film sections.
When the polymer layer is a polymer layer composed of a plurality of layers having different contents of the compound having an oxazoline structure, the above-mentioned maximum value and minimum value in the layer containing the ultraviolet absorbing compound among the plurality of layers. Is preferably 30% or less of the maximum value, and more preferably 20% or less. The lower limit is not particularly limited and may be 0% or more.

[Thickness of polymer layer]
The thickness of the polymer layer is preferably 2.0 μm to 30 μm, more preferably 2.0 μm to 25 μm, and still more preferably 3.0 μm to 20 μm.
When the thickness of the polymer layer is 2.0 μm or more, the function of absorbing ultraviolet rays by the polymer layer is more easily exhibited.
When the thickness of the polymer layer is 30 μm or less, the transparency of the polymer layer is more excellent.
When the polymer layer is a polymer layer composed of a plurality of layers having different contents of the compound having an oxazoline structure, the thickness is a total value of the thicknesses of the plurality of layers.
When the polymer layer is a polymer layer composed of a plurality of layers having different contents of the compound having an oxazoline structure, the thickness of each layer is preferably 2.0 μm to 30 μm, more preferably 2.0 μm to 25 μm, 3 More preferably, the thickness is 0.0 μm to 20 μm.

[Polymer layer forming coating solution]
The polymer layer is preferably a layer formed by curing a coating solution for forming a polymer layer. The polymer layer includes a binder polymer and a compound having an oxazoline structure, and the content of the compound having an oxazoline structure is used for forming a polymer layer. A layer obtained by curing a coating solution for forming a polymer layer in a range of 12% by mass to 70% by mass with respect to the solid content of the coating solution is more preferable.
The coating liquid for forming a polymer layer may contain the above-described ultraviolet absorbing compound, a crosslinking agent, a crosslinking catalyst, a surfactant and the like.
The content of each component contained in the coating liquid for forming a polymer layer and the preferred embodiment thereof are the same as the solid content in the polymer layer described above.
The binder polymer is preferably resin particles dispersed in a coating solution for forming a polymer layer.
The compound having the oxazoline structure and the ultraviolet absorbing compound are also preferably resin particles dispersed in the coating solution for forming a polymer layer.
The curing method is not particularly limited, and examples thereof include a method in which a polymer layer-forming coating solution is applied on a substrate and then heated as necessary.

There is no restriction | limiting in particular in the solvent contained in the coating liquid for polymer layer formation.
The solvent may be water or an organic solvent such as toluene or methyl ethyl ketone. From the viewpoint of environmental load, water is preferable. The proportion of water in the solvent is preferably 60% by mass or more, and more preferably 80% by mass or more.
The preferred range of the content of each component with respect to the solid content of the coating liquid for forming a polymer layer is the same as the preferred range of the content of each component with respect to the solid content of the polymer layer.

[Method of forming polymer layer]
The method for forming the polymer layer is not particularly limited.
Examples of the method for forming the polymer layer include a method in which the polymer layer-forming coating solution described above is applied to one surface of a substrate and dried.
When the polymer layer is a polymer layer composed of a plurality of layers having different contents of the compound having an oxazoline structure, for example, a plurality of polymer layer forming coating solutions corresponding to the plurality of layers are prepared, and the respective coatings are prepared. The method of apply | coating a liquid sequentially on a base material, and making it dry is mentioned. Drying may be performed sequentially each time the coating liquid is applied, or may be performed collectively after a plurality of coating liquids are continuously applied.

There is no restriction | limiting in particular in the coating method which apply | coats the coating liquid for polymer layer formation.
Examples of the coating method include a coating method using a coating apparatus such as a gravure coater, a bar coater, a roll coater, a spin coater, or a curtain coater.

There is no particular limitation on the drying method for drying the coating liquid for forming the polymer layer, and a known method can be appropriately applied.
The drying temperature is preferably 100 ° C to 200 ° C, more preferably 140 ° C to 190 ° C.
The drying time is preferably 0.1 minutes to 10 minutes, more preferably 0.2 minutes to 5 minutes.

In addition, surface treatment (flame treatment, corona treatment, plasma treatment, ultraviolet treatment, etc.) may be performed on the substrate before forming the polymer layer.
The polymer layer may be disposed on the substrate via another layer (for example, an undercoat layer described later).

<Hard coat layer (second layer)>
The first laminate according to the present disclosure includes a hard coat layer (for example, the second layer 12 described above).
The hard coat layer is a layer (preferably the outermost surface layer) disposed on the polymer layer, and has a function of protecting the polymer layer and the substrate (for example, suppressing damage to the first layer and the substrate). It is.

Moreover, it is preferable that the pencil hardness of the surface of a hard-coat layer is B or more.
When the pencil hardness on the surface of the hard coat layer is B or more, the above-described scratch resistance is excellent.
Moreover, the scratch resistance of a hard-coat layer also improves that the pencil hardness of the surface of a hard-coat layer is B or more.
From the viewpoint of obtaining the above-described effect more effectively, the pencil hardness of the surface of the hard coat layer is preferably HB or more, and more preferably F or more.
The upper limit of the pencil hardness on the surface of the hard coat layer is not particularly limited, but the upper limit of the pencil hardness on the surface of the hard coat layer is preferably 3H or less, more preferably 2H or less.
In addition, the pencil hardness of the surface of a hard-coat layer means the value measured based on JISK5600-5-4: 1999. A high uni from Mitsubishi Pencil Co., Ltd. is used as the pencil.

The hard coat layer contains at least one siloxane resin including the structural unit represented by the formula S1 and the structural unit represented by the formula S2.
When the hard coat layer contains at least one siloxane resin, the scratch resistance of the hard coat layer (for example, scratch resistance against external forces such as scratching and scratching) can be ensured. Moreover, the transparency of a hard-coat layer can be ensured because a hard-coat layer contains a siloxane resin.

[Siloxane resin]
The siloxane resin contained in the hard coat layer is not particularly limited as long as it is a compound containing a structural unit represented by the following formula S1 and a structural unit represented by the following formula S2. The siloxane resin in the present disclosure does not include silica particles that are inorganic particles described later.
The siloxane resin contained in the hard coat layer may be only one type or two or more types.
[* -SiO _3/2 ] Formula S1
[SiO _4/2 ] Formula S2
In formula S1, * represents a binding site with another structure. However, the Si atom in Formula S1 is not directly bonded to the O atom at the bonding site.

The structural unit represented by the formula S1 is preferably a structural unit derived from a trifunctional alkoxysilane contained in a trifunctional or lower functional alkoxysilane described later. That is, the structure included in * is preferably a structure derived from R ^s3 described later.
The structural unit represented by the formula S2 is preferably a structural unit derived from a tetrafunctional alkoxysilane described later.

From the viewpoint of easily suppressing the occurrence of cracks in the hard coat layer and improving the pencil hardness, the amount of Si atom in the structural unit represented by the formula S1 in the siloxane resin is represented by the structural unit represented by the formula S2. It is preferably 1.0 to 7.5 times, and more preferably 1.5 to 4.5 times the molar amount of Si atoms in it.
In the case where two or more structural units represented by Formula S1 are included, “the Si atom molar amount of the structural unit represented by Formula S1” is the total Si atoms of the structural units represented by two or more Formulas S1. Mean molar amount.
When two or more types of structural units represented by Formula S2 are included, “the Si atom molar amount of the structural unit represented by Formula S2” is the total Si atoms of the structural units represented by two or more types of Formula S2. Mean molar amount.
In the above siloxane resin, when the molar amount of Si atom in the structural unit represented by Formula S1 is 1.0 times or more with respect to the molar amount of Si atom in the structural unit represented by Formula S2, the siloxane resin Toughness is improved, and the occurrence of cracks in the hard coat layer is suppressed.
When the molar amount of Si atoms in the structural unit represented by formula S1 in the siloxane resin is 7.5 times or less with respect to the molar amount of Si atoms in the structural unit represented by formula S2, The hardness of is improved, and the pencil hardness of the hard coat layer is improved.
The total value of the Si atomic mole amount of the structural unit represented by Formula S1 and the Si atomic mole amount of the structural unit represented by Formula S2 is 80 mol% with respect to the total Si atomic mole amount contained in the siloxane resin. Preferably, it is 90 mol% or more, more preferably 100 mol%.
The Si atom molar amount of the structural unit represented by Formula S1 and the Si atomic mole amount of the structural unit represented by Formula S2 in the siloxane resin are in the range of up to 50% in the film thickness direction from the surface of the hard coat layer. The siloxane resin of this part is scraped off, 10 mg is sampled therefrom, and this is analyzed by solid ²⁹ Si-NMR, which can be measured by the peak intensity of Si atoms in the trifunctional and tetrafunctional siloxanes.

  The siloxane resin contained in the hard coat layer preferably contains a hydrolytic condensate of a trifunctional or lower functional alkoxysilane and a tetrafunctional alkoxysilane from the viewpoint that the degree of crosslinking of the siloxane resin can be more easily adjusted.

At least one of the siloxane resins contained in the hard coat layer is a tetrafunctional alkoxysilane and a trifunctional or lower alkoxysilane having a mass of 1.4 to 10 times the mass of the tetrafunctional alkoxysilane. It is more preferable to contain a hydrolyzed condensate, and a tetrafunctional alkoxysilane and a trifunctional or lower alkoxysilane having a mass of 2.0 to 6.0 times the mass of the tetrafunctional alkoxysilane. It is further preferable to contain a hydrolysis condensate.
In this embodiment, the tetrafunctional alkoxysilane and the trifunctional or lower functional alkoxysilane may be one kind or two kinds or more, respectively.
When there are two or more tetrafunctional alkoxysilanes, the “amount of tetrafunctional alkoxysilane” means the total amount of two or more tetrafunctional alkoxysilanes.
When there are two or more trifunctional or lower alkoxysilanes, the “amount of trifunctional or lower alkoxysilane” means the total amount of two or more trifunctional or lower alkoxysilanes.

  Hereinafter, tetrafunctional alkoxysilane and trifunctional or lower alkoxysilane in an amount of X mass times to Y mass times (for example, 1.4 mass times to 10 mass times) with respect to the amount of the tetrafunctional alkoxysilane, and A siloxane resin that is a hydrolyzed condensate of, is a siloxane resin having a mass ratio [3 functional or less / 4 functional] of X to Y (for example, a mass ratio [3 functional or less / 4 functional] is 1.4 to 10).

When at least one of the siloxane resins contained in the hard coat layer is a siloxane resin having a mass ratio [less than or equal to 3 functions / 4 functions] of 1.4 to 10, the occurrence of cracks in the hard coat layer is easily suppressed. Pencil hardness is easy to improve.
Specifically, when the mass ratio [trifunctional or lower / 4 functional] is 1.4 or more, the toughness of the siloxane resin is improved and the occurrence of cracks in the hard coat layer is suppressed.
When the mass ratio [trifunctional or lower / 4 functional] is 10 or lower, the hardness of the siloxane resin is improved, and the pencil hardness of the hard coat layer is improved.
The proportion of the siloxane resin having a mass ratio [trifunctional or tetrafunctional / 4 functional] of all siloxane resins contained in the hard coat layer of 1.4 to 10 is preferably 80% by mass or more, and 90% by mass. The above is more preferable, and 100% by mass is particularly preferable.

The mass ratio [trifunctional or lower / 4 functional] in the siloxane resin having the above-described mass ratio [trifunctional or lower / 4 functional] is 1.4 to 10 from the viewpoint of suppressing cracking of the hard coat layer and improving the pencil hardness. 2.0 to 6.0 is preferable.
In other words, from the viewpoint of further suppressing the occurrence of cracks in the hard coat layer and further improving the pencil hardness, at least one of the siloxane resins contained in the hard coat layer is a tetrafunctional alkoxysilane and the tetrafunctional alkoxysilane. Hydrolysis condensate of tri- or lower-functional alkoxysilane having a mass of 2.0 to 6.0 times the total mass of alkoxysilane (that is, a mass ratio [tri-functional or lower / four-functional] is 2.0) A siloxane resin of ˜6.0).
In this case, the ratio of the siloxane resin in which the mass ratio [trifunctional or lower / 4 functional] in all the siloxane resins contained in the hard coat layer is 2.0 to 6.0 is 80% by mass or more. Preferably, it is 90 mass% or more, and it is especially preferable that it is 100 mass%.

In the present specification, the tetrafunctional alkoxysilane means an alkoxysilane in which the number of alkoxy groups directly bonded to a silicon atom is four in one molecule.
In the present specification, the trifunctional or lower functional alkoxysilane means an alkoxysilane having 1 or more and 3 or less alkoxy groups directly bonded to a silicon atom in one molecule.

-4-functional alkoxysilane-
Although there is no restriction | limiting in particular as tetrafunctional alkoxysilane, The alkoxysilane represented with the following general formula (a) is preferable.

Si (OR ^S1 ) ₄ ... General formula (a)

In general formula (a), four R ^<S1 > represents a C1-C6 alkyl group each independently.
The four R ^{1 s} are each independently preferably an alkyl group having 1 to 4 carbon atoms (more preferably 1 to 3, particularly preferably 1 or 2).

Specific examples of the tetrafunctional alkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methoxytriethoxysilane, ethoxytrimethoxysilane, methoxytripropoxysilane, ethoxytripropoxysilane, and propoxytrimethoxysilane. , Propoxytriethoxysilane, dimethoxydiethoxysilane and the like.
Among these, tetramethoxysilane or tetraethoxysilane is preferable.

-3 functional alkoxysilanes
The trifunctional or lower alkoxysilane is not particularly limited, but an alkoxysilane represented by the following general formula (b) is preferable.

R ^S3 _4-n Si (OR ^S2 ) _n ... General formula (b)

In general formula (b), n represents the integer of 1-3.
R ^S2 represents an alkyl group having 1 to 6 carbon atoms.
When n is 2 or 3, the plurality of R ^S2 may be the same or different.
R ^S3 represents an organic group having 1 to 15 carbon atoms.
When 4-n is 2 or 3, the plurality of R ^S3 may be the same or different.

A preferred embodiment of R ^{S2 in} the general formula (b) is the same as the preferred embodiment of R ^{S1 in} the general formula (a).

  N in the general formula (b) is preferably 2 or 3, and particularly preferably 3.

R ^S3 in the general formula (b) represents an organic group having 1 to 15 carbon atoms.
When the carbon number of R ^S3 is 1 to 15, the hardness of the hard coat layer and the adhesion between the hard coat layer and the polymer layer are improved.
The organic group represented by R ^S3 may have a heteroatom such as oxygen, nitrogen, or sulfur. When the organic group represented by R ^S3 has a hetero atom, the adhesion between the hard coat layer and the polymer layer can be further improved.
As the organic group represented by R ^S3 ,
A substituted or unsubstituted hydrocarbon group is preferred,
A substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group is more preferable.

The organic group represented by R ^S3 preferably contains an epoxy group.
The organic group represented by R ^S3 is more preferably a hydrocarbon group substituted by a substituent containing an epoxy group, and still more preferably an alkyl group substituted by a substituent containing an epoxy group.
Examples of the substituent containing an epoxy group include an epoxy group, a glycidyl group, a glycidoxy group, a 3,4-epoxycyclohexyl group, and the like.

The organic group represented by R ^S3 may include an alkyl group, an alkenyl group, an aryl group, an amide group, a urethane group, a urea group, an ester group, a hydroxy group, a carboxy group, a (meth) acryloyl group, and the like.

The organic group represented by R ^S3 preferably does not contain an amino group.
The reason is that when the organic group represented by R ^S3 contains an amino group, dehydration condensation is promoted between the silanols produced by mixing and hydrolyzing a tetrafunctional alkoxysilane and a trifunctional or lower alkoxysilane. This is because the reaction solution may become unstable.

The trifunctional or lower functional alkoxysilane preferably contains an epoxy group as described above.
Specific examples of the tri- or lower functional alkoxysilane containing an epoxy group include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 2- (3 , 4-epoxycyclohexyl) ethyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxy Silane, 3-glycidoxypropyl triethoxysilane, etc. are mentioned.
Examples of commercially available trifunctional or lower functional alkoxysilanes containing an epoxy group include KBE-403 (manufactured by Shin-Etsu Chemical Co., Ltd.).

Specific examples of the trifunctional or lower alkoxysilane containing no epoxy group include vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3- Ureidopropyltrimethoxysilane, propyltrimethoxysilane, phenyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltriethoxysilane, 3-chloropropyltriethoxysilane, 3-ureido Propyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, ethyltrimethoxysilane, propyltriethoxysilane, propyltrimethoxysilane , Phenyltriethoxysilane, phenyltrimethoxysilane, and the like.
Examples of commercially available trifunctional or lower alkoxysilanes that do not contain an epoxy group include KBE-13 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  The content of the siloxane resin contained in the hard coat layer is preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more based on the solid content of the hard coat layer.

[Inorganic particles]
The hard coat layer preferably contains at least one inorganic particle from the viewpoint of further improving the hardness of the hard coat layer.
The inorganic particles are preferably at least one inorganic particle selected from the group consisting of metal oxide particles and inorganic nitride particles from the viewpoint of further improving the hardness of the hard coat layer.

Examples of the metal oxide particles include silica particles, alumina particles, zirconia particles, and titania particles.
Examples of the inorganic nitride particles include boron nitride particles.

  It is preferable that a hard-coat layer contains a silica particle from a viewpoint of bridge | crosslinking with the siloxane resin in a hard-coat layer.

Examples of the silica particles include dry powdered silica produced by combustion of silicon tetrachloride; colloidal silica in which silicon dioxide or a hydrate thereof is dispersed in water; and the like.
When using dry powdery silica, it can be used by dispersing in water using an ultrasonic disperser or the like.
Silica particles are not particularly limited, and specifically, Seahoster series such as Seahoster KE-P10 (manufactured by Nippon Shokubai Co., Ltd.), Snowtex (registered trademark) series such as Snowtex (registered trademark) OZL-35 ( Nissan Chemical Industries, Ltd.).

The number average particle diameter of the inorganic particles is preferably 300 nm or less, more preferably 200 nm or less, and particularly preferably 100 nm or less.
When the number average particle diameter of the inorganic particles is 300 nm or less, a hard coat layer having a smooth surface can be obtained.
On the other hand, the number average particle diameter of the inorganic particles is preferably 5 nm or more, and more preferably 10 nm or more.
The hardness of a hard-coat layer can be improved more as the number average particle diameter of an inorganic particle is 5 nm or more.

The number average particle size of the inorganic particles is determined by observing the cross section of the hard coat layer with a scanning electron microscope (SEM), selecting 100 particles included in a range corresponding to an actual area of 1 mm ^2, and determining the particle size of each particle. It refers to a value determined by measuring and simply averaging the measured values (particle size of each particle).

The content of the inorganic particles is preferably 5% by mass to 60% by mass, more preferably 10% by mass to 50% by mass, and more preferably 20% by mass to 50% by mass with respect to the solid content of the hard coat layer. It is particularly preferred that
The total amount of the siloxane resin and the inorganic particles is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass with respect to the solid content of the hard coat layer.

[Metal complex]
The hard coat layer preferably contains a metal complex as a curing agent.
As the metal complex, a metal complex containing at least one metal element selected from the group consisting of aluminum, magnesium, manganese, titanium, copper, cobalt, zinc, hafnium and zirconium is preferable.

A metal complex can be easily obtained by reacting a metal alkoxide with a chelating agent.
Examples of chelating agents include β-diketones such as acetylacetone, benzoylacetone, and dibenzoylmethane; β-ketoacid esters such as ethyl acetoacetate and ethyl benzoylacetate;
As the metal complex, an aluminum chelate complex is preferable.

Examples of metal complexes include ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum monoacetylacetonate bis (ethylacetoacetate), aluminum tris (acetylacetonate) Aluminum chelate complexes such as;
Magnesium chelate complexes such as ethyl acetoacetate magnesium monoisopropylate, magnesium bis (ethylacetoacetate), alkyl acetoacetate magnesium monoisopropylate, magnesium bis (acetylacetonate);
Zirconium chelate complexes such as zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, zirconium acetylacetonate bis (ethylacetoacetate);
Manganese chelate complexes such as manganese acetylacetonate;
Cobalt chelate complexes such as cobalt acetylacetonate;
Copper chelate complexes such as copper acetylacetonate;
Titanium chelate complexes such as titanium acetylacetonate and titanium oxyacetylacetonate;
Etc.
Of these, aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), magnesium bis (acetylacetonate), magnesium bis (ethylacetoacetate), or zirconium tetraacetylacetonate is preferable. In view of storage stability and availability, aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), or aluminum monoacetylacetonate bis (ethylacetoacetate) is particularly preferable.

  Examples of commercially available metal complex solutions include aluminum chelate A (W), aluminum chelate D, and aluminum chelate M (manufactured by Kawaken Fine Chemical Co., Ltd.).

The content of the metal complex in the hard coat layer is preferably 5% by mass to 50% by mass, more preferably 5% by mass to 40% by mass, and still more preferably 10% by mass to 30% by mass with respect to the total amount of siloxane.
When the metal complex is used in the above lower limit or more, the reaction rate of dehydration condensation of silanol can be set to an appropriate rate, and a hard coat layer having excellent thickness uniformity and high alkali resistance can be obtained.

[Other ingredients]
The hard coat layer may contain other components other than the components described above.
For example, the hard coat layer may contain at least one surfactant.
Thereby, the slip property of the surface of a hard-coat layer improves, and the friction of the hard-coat layer surface is reduced.
As the surfactant, various surfactants such as a fluorine-based surfactant, a nonionic surfactant, a cationic surfactant, an anionic surfactant, and a silicone-based surfactant can be used.

Only one type of surfactant may be used, or two or more types may be combined.
The content of the surfactant is preferably 0.001% by mass to 10% by mass, more preferably 0.01% by mass to 5% by mass, and still more preferably with respect to the solid content of the hard coat layer. It is 0.1 mass%-1 mass%.

The hard coat layer (or hard coat layer forming coating solution) may contain a pH adjuster.
Examples of the pH adjuster include acids such as nitric acid, oxalic acid, acetic acid, formic acid and hydrochloric acid, and alkalis such as ammonia, triethylamine, ethylenediamine, sodium hydroxide and potassium hydroxide.

The thickness of the hard coat layer is preferably 0.1 μm to 5 μm, more preferably 0.2 μm to 4 μm, and still more preferably 0.3 μm to 3 μm.
When the thickness of the hard coat is 0.1 μm or more, it is advantageous in terms of the hardness of the hard coat layer surface.
When the thickness of the hard coat layer is 5 μm or less, the transparency and handleability of the first laminate are further improved.

[Method of forming hard coat layer]
The method for forming the hard coat layer is not particularly limited.
As a method for forming a hard coat layer, for example, a coating solution for forming a hard coat layer containing a solvent and a hydrolyzate of alkoxysilane is coated on the polymer layer and dried to thereby hydrolyze the alkoxysilane hydrolysis condensate. And a method of forming a hard coat layer containing a siloxane resin.
Regarding the solvent in the hard coat layer forming coating solution, and the coating method and drying method of the hard coat layer forming coating solution, the solvent in the polymer layer forming coating solution and the coating method of the polymer layer forming coating solution described above. And the same application method.

As a method for preparing the coating liquid for forming a hard coat layer, alkoxysilane (for example, tetrafunctional alkoxysilane and trifunctional or lower alkoxysilane) is hydrolyzed, and the resulting trifunctional alkoxysilane hydrolyzate and 4 A method of obtaining a coating liquid for forming a hard coat layer containing a hydrolyzate of a functional alkoxysilane is preferred.
Prepare a coating solution for forming a hard coat layer containing components other than the hydrolyzate of alkoxysilane (for example, inorganic particles, metal complexes, surfactants, silicone particles (eg, silicone powder manufactured by Shin-Etsu Chemical Co., Ltd.)) In the above preparation method, at least one stage (preferably after the hydrolysis of alkoxysilane) before hydrolysis of alkoxysilane, during hydrolysis of alkoxysilane, and after hydrolysis of alkoxysilane. Components other than the alkoxysilane hydrolyzate are added.
In this example of the method for forming a hard coat layer, the resulting coating liquid for forming a hard coat layer is applied and dried to obtain a siloxane resin (and other components as required) that are hydrolysis condensates of alkoxysilane. ) Containing a hard coat layer.

The amount of alkoxysilane used (for example, the total amount of tetrafunctional alkoxysilane and trifunctional or lower alkoxysilane) during the preparation of the hard coat layer forming coating solution is the solid content of the hard coat layer forming coating solution. On the other hand, 20 mass%-80 mass% are preferable, 20 mass%-70 mass% are more preferable, 30 mass%-70 mass% are especially preferable.
The preferred range of the use amount ratio (mass ratio) of the tetrafunctional alkoxysilane and the trifunctional or lower functional alkoxysilane when preparing the coating solution for forming the hard coat layer is the above-mentioned siloxane (that is, the hydrolysis condensate of alkoxysilane) ) Mass ratio [trifunctional or lower / 4 functional] is the same as the preferable range.
When the hard coat layer containing the above-mentioned inorganic particles is formed, the content of the inorganic particles in the hard coat layer forming coating solution is 5% by mass to 60% by mass with respect to the solid content of the hard coat layer forming coating solution. It is preferable that it is 10 mass%-50 mass%, and it is especially preferable that it is 20 mass%-50 mass%.
When the hard coat layer containing the metal complex is formed, the content of the metal complex in the hard coat layer forming coating solution is 5% by mass to 50% with respect to the total amount of alkoxysilane in the hard coat layer forming coating solution. % By mass is preferable, 5% by mass to 40% by mass is more preferable, and 10% by mass to 30% by mass is further preferable. By using the metal complex in the above lower limit or more, the reaction rate of silanol dehydration condensation can be set to an appropriate rate, and a hard coat layer having a uniform thickness and high alkali resistance can be formed.
When forming the hard coat layer containing the above-mentioned surfactant, the content of the surfactant in the coating liquid for forming the hard coat layer is preferably 0.001% by mass to 10% with respect to the solid content of the hard coat. It is mass%, More preferably, it is 0.01 mass%-5 mass%, More preferably, it is 0.1 mass%-1 mass%.

<Back layer>
Even if the 1st laminated body concerning this indication is provided with the back layer on the opposite side (namely, back side of a substrate) to the polymer layer side (namely, the front side of a substrate) of a substrate, Good.
A back surface layer functions as a layer for adhesion | attachment with the sealing material (For example, sealing material containing ethylene-vinyl acetate copolymer (EVA)) in a solar cell module, for example.
The back layer preferably contains a binder polymer.
The back layer may be a single layer or two or more layers.

For example, the first laminated body has a third layer (for example, the above-described third layer 13) and a fourth layer (for example, the above-described fourth layer 14) on the back surface side of the substrate as the back layer. You can prepare in order.
Hereinafter, the 3rd layer and 4th layer with which a 1st laminated body is equipped as needed are demonstrated.

[Third layer]
The third layer preferably contains a binder polymer.
Examples of the binder polymer that can be contained in the third layer include those similar to the binder polymer in the polymer layer.
As the binder polymer that can be contained in the third layer, for example, an acrylic resin or an acrylic resin containing a styrene skeleton is more preferable from the viewpoint of adhesion to a sealing material when applied to a solar cell module.

As the acrylic resin containing a styrene skeleton, a structural unit derived from at least one compound selected from the group consisting of acrylic acid, methacrylic acid, acrylic ester, and methacrylic ester, and a monomer having a styrene skeleton (for example, And a polymer containing a structural unit derived from styrene, α-methylstyrene, divinylbenzene, vinyltoluene and the like.
Examples of commercially available acrylic resin dispersions containing a styrene skeleton include AS-563A (manufactured by Daicel Finechem Co., Ltd.).

The third layer may contain an ultraviolet absorbing compound.
Examples of the ultraviolet absorbing compound that can be contained in the third layer include the same ultraviolet absorbing compound as that of the polymer layer.

The third layer can contain a structure derived from a crosslinking agent and a crosslinking catalyst.
As for the crosslinking agent and the crosslinking catalyst, the same as the crosslinking agent and the crosslinking catalyst in the polymer layer may be used.
In addition, as a component which can be contained in a 3rd layer, the component similar to the component of a polymer layer is mentioned.

The thickness of the third layer is preferably thicker than the thickness of the fourth layer, which is an easy-adhesion layer described later, from the viewpoint of improving the adhesion with the sealing material. That is, when the thickness of the third layer is (b) and the thickness of the fourth layer is (c), the relationship of (b)> (c) is preferable, and (b) :( c) is A range of 2: 1 to 15: 1 is more preferable.
In addition, the thickness of the third layer is preferably 0.5 μm or more, and more preferably 0.7 μm or more. The thickness of the third layer is preferably 7.0 μm or less.

  When the thickness of the third layer and the ratio of the thickness of the third layer to the thickness of the fourth layer are within the above range, the film characteristics of the third layer are well expressed, and the first laminate and the sealing material The adhesiveness of the solar cell module and the durability of the solar cell module are further improved.

The method for forming the third layer is not particularly limited.
As a method for forming the third layer, for example, there is a method in which a third layer forming coating liquid containing a solvent and the above-described third layer component (solid content) is applied on the back surface of the substrate and dried. Can be mentioned.
The solvent and the coating method in the third layer forming coating solution are the same as the solvent and the coating method in the polymer layer forming coating solution described above.

[Fourth layer]
The 1st laminated body of this indication may be equipped with the 4th layer (for example, above-mentioned 4th layer 14) on the 3rd above-mentioned layer.
The fourth layer is a layer that directly contacts the sealing material of the solar cell module, that is, a layer that functions as an easy adhesion layer for the sealing material of the solar cell module.

The fourth layer preferably contains a binder polymer.
Examples of the binder polymer that can be contained in the fourth layer include those similar to the binder polymer of the polymer layer.
The binder polymer in the fourth layer is preferably at least one polymer selected from the group consisting of polyolefins, acrylic resins, polyesters, and polyurethanes from the viewpoint of adhesion with the sealing material.
The binder polymer in the fourth layer preferably contains at least polyolefin, and more preferably polyolefin, from the viewpoint of adhesion with the sealing material.

As the polyolefin, for example, a modified polyolefin is preferable.
When forming the 4th layer containing polyolefin, you may use the commercial item of the dispersion of polyolefin.
Examples of commercially available polyolefin dispersions include Arrow Base (registered trademark) SE-1013N, SD-1010, TC-4010, TD-4010 (both manufactured by Unitika Ltd.), Hitech S3148, S3121, and S8512 (both Toho Chemical Co., Ltd.), Chemipearl (registered trademark) S-120, S-75N, V100, EV210H (both manufactured by Mitsui Chemicals, Inc.) and the like.
Among them, the use of Arrowbase (registered trademark) SE-1013N, manufactured by Unitika Co., Ltd., which is a terpolymer of low-density polyethylene, acrylic acid ester, and maleic anhydride, improves adhesion. preferable.

The fourth layer can contain a structure derived from a crosslinking agent and a crosslinking catalyst.
About a crosslinking agent and a crosslinking catalyst, the thing similar to the crosslinking agent and crosslinking catalyst in a polymer layer is mentioned.
In addition, as a component which may be contained in the 4th layer, the component similar to the component of a polymer layer is mentioned.

The fourth layer may contain an antistatic agent, a preservative, and the like.
Examples of the antistatic agent include surfactants such as nonionic surfactants and organic conductive materials.
As the surfactant used in the antistatic agent that can be contained in the fourth layer, nonionic surfactants, anionic surfactants, and the like are preferable. Among these, nonionic surfactants are preferable, and ethylene glycol chains (polyoxyethylene chains) are preferable. A nonionic surfactant having — (CH ₂ —CH ₂ —O) _n —) and not having a carbon-carbon triple bond (alkyne bond) is preferable. Furthermore, the thing whose ethylene glycol chain is 7-30 is especially preferable.
More specifically, hexaethylene glycol monododecyl ether, 3,6,9,12,15-pentaoxahexadecan-1-ol, polyoxyethylene phenyl ether, polyoxyethylene methyl phenyl ether, polyoxyethylene naphthyl ether, Examples thereof include polyoxyethylene methyl naphthyl ether, but are not limited thereto.
The content of the surfactant as the antistatic agent is preferably 2.5% by mass to 40% by mass, and more preferably 5.0% by mass to 35% by mass with respect to the solid content of the fourth layer. Yes, more preferably 10% by mass to 30% by mass.
When the content is within this range, a decrease in the partial discharge voltage is suppressed, and adhesion with the sealing material is favorably maintained.

  Examples of organic conductive materials include cationic conductive compounds having cationic substituents such as ammonium groups, amine bases, and quaternary ammonium groups in the molecule; sulfonate groups, phosphate groups, carboxylate groups, and the like. Anionic conductive compounds having anionic properties of: an ionic conductive material such as an amphoteric conductive compound having both an anionic substituent and a cationic substituent; polyacetylene derived from a conjugated polyene skeleton, poly Examples thereof include conductive polymer compounds such as paraphenylene, polyaniline, polythiophene, polyparaphenylene vinylene, and polypyrrole.

The method for forming the fourth layer is not particularly limited.
Examples of the method for forming the fourth layer include a method in which a fourth layer forming coating solution containing a solvent and the above-described fourth layer component (solid content) is applied onto the third layer and dried. .
The solvent and the coating method in the fourth layer forming coating solution are the same as the solvent and the coating method in the polymer layer forming coating solution described above.

<Base material>
Next, the preferable aspect of the base material (for example, above-mentioned base film 10) in the 1st laminated body which concerns on this indication is demonstrated.
As the base material, a transparent material can be appropriately selected.
An undercoat layer to be described later may be provided on at least one surface of the substrate.
As the substrate, a film-like substrate (also referred to as “substrate film”) is preferable.

  The thickness of a base film becomes like this. Preferably they are 30 micrometers-500 micrometers, More preferably, they are 40 micrometers-450 micrometers, More preferably, they are 45 micrometers-400 micrometers.

The material of the substrate is preferably a polymer.
Examples of the polymer include polyolefins such as polyester, polycarbonate, polypropylene, and polyethylene, or fluorine-based polymers such as polyvinyl fluoride. Among these, polyester is preferable from the viewpoint of cost, mechanical strength, and transparency.

〔polyester〕
Examples of the polyester include a linear saturated polyester synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Specific examples of the linear saturated polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylenedimethylene terephthalate), polyethylene-2,6-naphthalate, and the like. Of these, polyethylene terephthalate, polyethylene-2,6-naphthalate, and poly (1,4-cyclohexylenedimethylene terephthalate) are particularly preferable from the viewpoint of the balance between mechanical properties and cost.

  The polyester may be a homopolymer or a copolymer. Further, polyester may be blended with a small amount of other types of resins such as polyimide.

  The kind of polyester is not limited to the above, and a known polyester may be used. As well-known polyester, you may synthesize | combine using a dicarboxylic acid component and a diol component, and may use commercially available polyester.

[Example of substrate manufacturing method]
The method for producing the substrate is not particularly limited.
For example, the manufacturing method of the base film of Unexamined-Japanese-Patent No. 2006-195165 is mentioned.

<Undercoat layer>
As described above, an undercoat layer may be provided on at least one of the front surface (surface on which the polymer layer is formed) and the back surface (surface on which the optional back surface layer is formed) of the base material.

The undercoat layer preferably contains a binder polymer.
The binder polymer that can be contained in the undercoat layer is not particularly limited.
Examples of the binder polymer that can be contained in the undercoat layer include acrylic resin, polyester, polyolefin, and silicone.
The undercoat layer preferably contains an acrylic resin.
As an acrylic resin, the thing similar to the acrylic resin which may be contained in the 3rd layer mentioned above is mentioned.
The acrylic resin content ratio in the binder polymer contained in the undercoat layer is more preferably 50% by mass or more.
When the acrylic resin is 50% by mass or more of the binder polymer, it is easy to adjust the elastic modulus of the undercoat layer to 0.7 GPa or more, and the cohesive failure resistance in the case of a solar cell front sheet is further improved.

The undercoat layer may contain a structure derived from a crosslinking agent, a crosslinking catalyst, a surfactant, an antioxidant, a preservative, and the like.
For the structure derived from the crosslinking agent and the crosslinking catalyst, the description of the polymer layer can be referred to as appropriate.

The thickness of the undercoat layer is preferably 0.01 μm or more, more preferably 0.03 μm or more, and further preferably 0.05 μm or more.
Further, the thickness of the undercoat layer is preferably 1 μm or less, more preferably 0.8 μm or less, and even more preferably 0.7 μm or less.

The undercoat layer can be formed by applying a coating solution for forming an undercoat layer containing a solvent and a solid content of the undercoat layer on a substrate and drying it.
The solvent and coating method in the undercoat layer forming coating solution are the same as the solvent and coating method in the polymer layer forming coating solution described above.
The undercoat layer may be formed by an in-line coating method using the above undercoat layer forming coating solution.
The in-line coating method is a method in which a coating liquid for forming an undercoat layer is applied at a stage before winding up the manufactured base material. Differentiated.
As an aspect of forming an undercoat layer by an in-line coating method, a film in which an undercoat layer-forming coating solution is applied to one surface of a film stretched in the first direction, A mode in which a substrate with an undercoat layer is produced by stretching in a second direction perpendicular to the first direction along the surface is preferable (see Examples described later).

The 1st laminated body concerning this indication may be provided with other layers other than the layer mentioned above.
In the first laminate according to the present disclosure, the light transmittance at a wavelength of 400 nm to a wavelength of 1200 nm is preferably 80% or more, more preferably 83% or more, and 85% or more. Is more preferable. The transmittance is measured using a spectrophotometer V670 (manufactured by JASCO Corporation).

(Second embodiment of laminate)
Hereinafter, the second laminate according to the present disclosure will be described.
The second laminate includes a polymer layer containing a binder polymer on at least one surface of the base material, and a hard coat layer disposed on the surface of the polymer layer and containing a siloxane resin, at 25 ° C. As a result of performing a cross-cut adhesion test according to the method described in JISK5600-5-6, the hard coat layer was not cracked after irradiation with a metal halide lamp having a wavelength of 300 nm to 400 nm and an intensity of 90 mW / cm ² for 500 hours. The area of the part is within 20%.

<Polymer layer (first layer)>
The polymer layer in the second laminate is not particularly limited except that it contains a binder polymer.
Moreover, as a binder polymer in a polymer layer, it is synonymous with the binder polymer contained in the polymer layer in the above-mentioned 1st laminated body, and its preferable aspect is also the same.
In addition, the polymer layer in the second laminate is preferably a polymer layer similar to the polymer layer in the first laminate described above.

<Hard coat layer (second layer)>
The polymer layer in the second laminate is not particularly limited except that it contains a siloxane resin.
As a siloxane resin, it is synonymous with the siloxane resin in the above-mentioned 1st laminated body, and its preferable aspect is also the same.
In addition, the hard coat layer in the second laminate is preferably the same hard coat layer as the hard coat layer in the first laminate described above.

<Base material and other layers>
The base material in a 2nd laminated body is synonymous with the base material in a 1st laminated body, and its preferable aspect is also the same.
The second laminate may have a third layer, a fourth layer, an undercoat layer, etc. as other layers. These layers are synonymous with these layers in the above-mentioned first laminate, and preferred embodiments are also the same.

<Hardness of hard coat layer>
The second laminate according to the present disclosure has no cracks in the hard coat layer after irradiation with a metal halide lamp having a wavelength of 300 nm to 400 nm and an intensity of 90 mW / cm ² for 500 hours.
Here, the absence of cracks in the hard coat layer means that the haze value of the second laminate measured according to JIS K7136 using a turbidimeter (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.) is 5. It means 0 or more.

<Cross-cut adhesion test>
As a result of the cross-cut adhesion test performed on the second laminate according to the present disclosure by the method described in JISK5600-5-6, the area of the peeled portion is within 20%.
Specifically, the surface of the second laminate on the side of the hard coat layer is scratched in 11 vertical and horizontal directions at 1 mm intervals using a cutter to form 100 squares. A cellophane adhesive tape (cello tape (registered trademark) No. 405, 24 mm width, manufactured by Nichiban Co., Ltd.) is pasted on this, and the area of the peeled portion when peeled by quickly pulling in the vertical (90 °) direction is 20 %.

(Laminate manufacturing method)
A preferred method for producing a laminate according to the present disclosure is as follows.
Preparing a substrate;
Preparing a coating solution for forming a polymer layer containing a binder polymer and a compound having an oxazoline structure;
Preparing a coating liquid for forming a hard coat layer containing a hydrolyzate of trifunctional alkoxysilane and a hydrolyzate of tetrafunctional alkoxysilane;
A step of applying a polymer layer-forming coating solution on one side of the substrate and drying to form a polymer layer; and
On the surface of the polymer layer, a coating liquid for forming a hard coat layer is applied and dried to contain a structural unit represented by the above formula S1 and a siloxane resin containing the structural unit represented by the above formula S2. Forming a hard coat layer,
including.
According to this preferable manufacturing method, it is easy to manufacture the protective sheet for solar cells according to the present disclosure described above, particularly the front sheet for solar cells.

  The step of preparing the base material, the step of preparing the coating solution for forming the polymer layer, and the step of preparing the coating solution for forming the hard coat layer are all convenient steps, and the order of these three steps is particularly limited. There is no.

  In the preferable manufacturing method, the concept of “preparing” includes both simply preparing a base material and each coating solution that have been manufactured and stored in advance, and manufacturing the base material and each coating solution. Is done.

The step of preparing the substrate may be a step of manufacturing the substrate.
A preferred embodiment of the method for producing the substrate is as described above.
The step of producing a substrate may include a step of producing a composition for forming an undercoat layer for forming an undercoat layer and a step of producing a substrate with an undercoat layer.

The step of preparing the polymer layer forming coating solution may be a step of preparing the polymer layer forming coating solution. The preferred embodiment of the method for preparing the polymer layer forming coating solution is as described above.
In particular, the content of the compound having an oxazoline structure is preferably 12% by mass to 70% by mass with respect to the solid content of the coating liquid for forming a polymer layer.
Moreover, the preferable aspect of the process of apply | coating the coating liquid for polymer layer formation, and making it dry and forming a polymer layer is also as above-mentioned.

The step of preparing the hard coat layer forming coating solution may be a step of producing a hard coat layer forming coating solution. The preferred embodiment of the method for producing the hard coat layer forming coating solution is as described above.
Moreover, the preferable aspect of the process of apply | coating the coating liquid for hard-coat layer formation and making it dry and forming a hard-coat layer is also as above-mentioned.

  The preferable manufacturing method includes a step of preparing a coating solution for forming a back layer for forming the above back layer (for example, at least one of the third layer and the fourth layer), and a back layer on the back surface of the substrate. A step of applying a forming coating solution and drying it to form a back layer may be included.

(Solar cell module)
The solar cell module according to the present disclosure (for example, the solar cell module 100 described above)
An element structure unit (for example, the above-described element structure unit 36) including a solar cell element (for example, the above-described solar cell element 32) and a sealing material (for example, the above-described sealing material 34) for sealing the solar cell element; ,
A laminate (for example, the above-described solar cell front sheet 20) according to the present disclosure, which is disposed on a side where sunlight (for example, the above-described sunlight 50) is incident on the element structure;
A solar cell backsheet (for example, the solar cell backsheet 40 described above) disposed on the side opposite to the side on which sunlight is incident on the element structure, and
Is provided.

  An example of the solar cell module according to the present disclosure (solar cell module 100) has already been described with reference to FIG.

  Regarding the solar cell backsheet, for example, publicly known documents such as JP2012-19558A, JP2015-186861A, JP2015-185687A, and JP2015-146360A can be appropriately referred to.

  For each member of the solar cell module, for example, “Solar power generation system constituent material” (supervised by Eiichi Sugimoto, Kogyo Kenkyukai, 2008) can also be referred to.

  Solar cell elements include silicon solar cell elements including single crystal silicon, polycrystalline silicon, amorphous silicon, etc .; compound semiconductors such as copper-indium-gallium-selenium, copper-indium-selenium, cadmium-tellurium, gallium-arsenide Various known solar cell elements, such as a compound semiconductor solar cell element containing, can be applied.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.
Hereinafter, unless otherwise specified, “part” is based on mass.

<Preparation of hard coat layer forming coating solution>
Coating liquids A to H for forming a hard coat layer having the following composition were prepared.

-Preparation of coating liquid A for forming a hard coat layer-
<< Composition >>
・ Trifunctional alkoxysilane (KBE-403 (3-glycidoxypropyltriethoxysilane), manufactured by Shin-Etsu Chemical Co., Ltd.)
... 8.5 parts tetrafunctional alkoxysilane (KBE-04 (tetraethoxysilane), manufactured by Shin-Etsu Chemical Co., Ltd.)
… 2.6 parts Aqueous acetic acid solution (Daicel, industrial acetic acid)
... 0.2 parts metal complex solution (aluminum chelate D, Kawaken Fine Chemicals, 76 mass% isopropyl alcohol (IPA) solution)
... 2.5 parts aqueous dispersion of inorganic particles (Snowtex (registered trademark) OZL-35, average particle size 100 nm, manufactured by Nissan Chemical Industries, Ltd., solid content 35.5% by mass)
24.5 parts of surfactant in water (Lapisol (registered trademark) A-90, manufactured by NOF Corporation, solid content 1% by mass, anionic surfactant)
... 3.3 parts Surfactant water dilution (Naroacty (registered trademark) CL-95, manufactured by Sanyo Chemical Industries, Ltd., solid content 1 mass%, nonionic surfactant)
... 2.3 parts / water ... Remaining amount of 100 parts in total Note that the molar amount of Si atoms in the structural unit represented by Formula S1 is the molar amount of Si atoms in the structural unit represented by Formula S2. On the other hand, it was 2.4 times.

In detail, the coating liquid for forming the hard coat layer was prepared according to the following procedure.
After adding KBE-403 to an acetic acid aqueous solution and fully hydrolyzing it, KBE-04 is added and fully hydrolyzed, and a mixture containing a hydrolyzate of these alkoxysilanes (KBE-403 and KBE-04) is added. A liquid was obtained. Next, this mixed solution was mixed with aluminum chelate D, Snowtex (registered trademark) OZL-35, surfactant (Lapisol (registered trademark) A-90), surfactant (Naroacty (registered trademark) CL-95), And the coating liquid A for hard-coat layer formation was obtained by adding water.

-Preparation of coating liquid B for forming a hard coat layer-
Addition amount of trifunctional alkoxysilane (KBE-403 (3-glycidoxypropyltriethoxysilane), manufactured by Shin-Etsu Chemical Co., Ltd.) and tetrafunctional alkoxysilane (KBE-04 (tetraethoxysilane) Shin-Etsu Chemical ( Hard coat layer coating solution B was obtained in the same manner as the preparation method of hard coating layer forming coating solution A, except that the addition amount was 4.2 parts and 6.9 parts, respectively. .
Note that the molar amount of Si atoms in the structural unit represented by Formula S1 was 0.5 times the molar amount of Si atoms in the structural unit represented by Formula S2.

-Preparation of coating liquid C for forming a hard coat layer-
Addition amount of trifunctional alkoxysilane (KBE-403 (3-glycidoxypropyltriethoxysilane), manufactured by Shin-Etsu Chemical Co., Ltd.) and tetrafunctional alkoxysilane (KBE-04 (tetraethoxysilane) Shin-Etsu Chemical ( The hard coat layer coating solution C was obtained in the same manner as in the preparation method of the hard coat layer forming coating solution A, except that the addition amount was 6.5 parts and 4.6 parts, respectively. .
Note that the molar amount of Si atoms in the structural unit represented by Formula S1 was 1.0 times the molar amount of Si atoms in the structural unit represented by Formula S2.

-Preparation of hard coat layer forming coating solution D-
Addition amount of trifunctional alkoxysilane (KBE-403 (3-glycidoxypropyltriethoxysilane), manufactured by Shin-Etsu Chemical Co., Ltd.) and tetrafunctional alkoxysilane (KBE-04 (tetraethoxysilane) Shin-Etsu Chemical ( The hard coat layer coating solution D was obtained in the same manner as the preparation method of the hard coat layer forming coating solution A, except that the addition amount was 7.4 parts and 3.7 parts, respectively. .
Note that the molar amount of Si atoms in the structural unit represented by Formula S1 was 1.5 times the molar amount of Si atoms in the structural unit represented by Formula S2.

-Preparation of coating liquid E for forming a hard coat layer-
Addition amount of trifunctional alkoxysilane (KBE-403 (3-glycidoxypropyltriethoxysilane), manufactured by Shin-Etsu Chemical Co., Ltd.) and tetrafunctional alkoxysilane (KBE-04 (tetraethoxysilane) Shin-Etsu Chemical ( Hard coat layer coating solution E was obtained in the same manner as the preparation method of hard coat layer forming coating solution A, except that the addition amount was 9.5 parts and 1.6 parts, respectively. .
Note that the molar amount of Si atoms in the structural unit represented by Formula S1 was 4.5 times the molar amount of Si atoms in the structural unit represented by Formula S2.

-Preparation of coating liquid F for forming a hard coat layer-
Addition amount of trifunctional alkoxysilane (KBE-403 (3-glycidoxypropyltriethoxysilane), manufactured by Shin-Etsu Chemical Co., Ltd.) and tetrafunctional alkoxysilane (KBE-04 (tetraethoxysilane) Shin-Etsu Chemical ( The hard coat layer coating solution F was obtained in the same manner as the hard coat layer forming coating solution A except that the addition amount was 10.1 parts and 1.0 part, respectively. .
Note that the molar amount of Si atoms in the structural unit represented by Formula S1 was 7.5 times the molar amount of Si atoms in the structural unit represented by Formula S2.

-Preparation of coating liquid G for forming a hard coat layer-
Addition amount of trifunctional alkoxysilane (KBE-403 (3-glycidoxypropyltriethoxysilane), manufactured by Shin-Etsu Chemical Co., Ltd.) and tetrafunctional alkoxysilane (KBE-04 (tetraethoxysilane) Shin-Etsu Chemical ( Hard coat layer coating solution G was obtained in the same manner as the preparation method of hard coating layer forming coating solution A, except that the addition amount was 10.6 parts and 0.5 parts, respectively. .
Note that the molar amount of Si atoms in the structural unit represented by Formula S1 was 15.9 times the molar amount of Si atoms in the structural unit represented by Formula S2.

In the hard coat layer formed using the coating liquids A to G for forming the hard coat layer, Si atoms in the structural unit represented by the formula S1 with respect to the molar amount of Si atoms in the structural unit represented by the formula S2 The molar content ratio is as shown in Table 1.

-Preparation of hard coat layer forming coating solution H-
<< Composition >>
Aqueous dispersion of siloxane-containing acrylic resin (Ceranate (registered trademark) WSA1070, manufactured by DIC Corporation, solid content: 38% by mass) (abbreviated as “WSA1070” in Table 1)
... 60 parts as a solid content. Water dilution of oxazoline-based crosslinking agent (Epocross (registered trademark) WS-700, manufactured by Nippon Shokubai Co., Ltd., solid content 25 mass%) (in Table 1, "WS-700" (Abbreviated)
... 40 parts as solid content-Water-diluted solution of fluorosurfactant [sodium = bis (3,3,4,4,5,5,6,6,6-nonafluorohexyl) = 2-sulfoniteoxys Cushinate, manufactured by Fuji Film Fine Chemical Co., Ltd., solid content: 2% by mass]
... 1.1 parts / water ... Remaining amount of 100 parts in total

Example 1
<Production of laminate>
In this example, a laminate having a laminate structure represented by hard coat layer (second layer) / polymer layer (first layer) / base material / undercoat layer / third layer / fourth layer was produced.

[Production of base film with undercoat layer]
A base film with an undercoat layer having a structure in which an undercoat layer was provided on the back surface of the base film was produced as follows.

-Synthesis of polyester-
About 123 kg of bis (hydroxyethyl) terephthalate was previously charged in a slurry of 100 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals) and 45 kg of ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.). The esterification reaction tank maintained at 2 × 10 ⁵ Pa was sequentially supplied over 4 hours, and the esterification reaction was further performed over 1 hour after the completion of the supply. Thereafter, 123 kg of the obtained esterification reaction product was transferred to a polycondensation reaction tank.

  Subsequently, 0.3% by mass of ethylene glycol was added to the polycondensation reaction tank to which the esterification reaction product had been transferred, based on the resulting polymer. After stirring for 5 minutes, an ethylene glycol solution of cobalt acetate and manganese acetate was added to 30 ppm and 15 ppm, respectively, with respect to the resulting polymer. After further stirring for 5 minutes, a 2% by mass ethylene glycol solution of a titanium alkoxide compound was added to 5 ppm with respect to the resulting polymer. Five minutes later, a 10% by mass ethylene glycol solution of ethyl diethylphosphonoacetate was added so as to be 5 ppm with respect to the resulting polymer. Thereafter, while stirring the low polymer at 30 rpm, the reaction system was gradually heated from 250 ° C. to 285 ° C. and the pressure was reduced to 40 Pa. The time to reach the final temperature and final pressure was both 60 minutes. When the predetermined stirring torque was reached, the reaction system was purged with nitrogen, returned to normal pressure, and the polycondensation reaction was stopped. Then, the polymer obtained by the polycondensation reaction was discharged into cold water in a strand shape and immediately cut to produce polymer pellets (diameter: about 3 mm, length: about 7 mm). The time from the start of decompression to the arrival of the predetermined stirring torque was 3 hours.

  Here, the titanium alkoxide compound used was the titanium alkoxide compound (Ti content = 4.44 mass%) synthesized in Example 1 of paragraph [0083] of JP-A-2005-340616.

-Solid state polymerization-
The pellets obtained above were held in a vacuum vessel maintained at 40 Pa at a temperature of 220 ° C. for 30 hours for solid phase polymerization.

-Production of polyester film-
The pellets after undergoing solid-phase polymerization as described above were melted at 280 ° C. and cast on a metal drum to produce an unstretched polyethylene terephthalate (PET) film having a thickness of about 3 mm.
Thereafter, the unstretched PET film was stretched 3.4 times in the machine direction (MD) at 90 ° C. Next, on one surface of the uniaxially stretched PET film stretched in MD, a coating solution for forming an undercoat layer having the following composition is stretched in the transverse direction (TD) so that the coating amount is 5.1 mL / m ^2. : Transverse Direction) It was applied by in-line coating before stretching.
The PET film coated with the undercoat layer forming coating solution was TD-stretched to form an undercoat layer having a thickness of 0.1 μm and an elastic modulus of 1.5 GPa. The TD stretching was performed under the conditions of a temperature of 105 ° C. and a stretching ratio of 4.5 times.
The PET film on which the undercoat layer is formed is heat-set at a film surface of 190 ° C. for 15 seconds, and then at 190 ° C. with an MD relaxation rate of 5% and a TD relaxation rate of 11%, MD direction and TD direction. The biaxially stretched PET film (substrate film with an undercoat layer) having a thickness of 250 μm with an undercoat layer was obtained by performing a thermal relaxation treatment.

-Composition of undercoat layer type composition-
-Acrylic resin aqueous dispersion: 21.9 parts [AS-563A, manufactured by Daicel Finechem Co., Ltd., solid content: latex having a styrene skeleton of 28% by mass]
・ Oxazoline-based crosslinking agent in water: 4.9 parts [Epocross (registered trademark) WS-700, manufactured by Nippon Shokubai Co., Ltd., solid content: 25 mass%]
-Fluorine-based surfactant diluted in water: 0.1 part [sodium bis (3,3,4,4,5,5,6,6,6-nonafluorohexyl) = 2-sulfonite oxysucci NART, manufactured by FUJIFILM Fine Chemical Co., Ltd., solid content: 2% by mass]
・ Distilled water: Remaining amount of 100 parts in total

[Formation of third layer]
A third layer-forming coating solution having the following composition was applied to the surface of the undercoat layer of the base film with the undercoat layer obtained above, and then dried at 170 ° C. for 2 minutes, whereby a thickness of 4.7 μm was obtained. Three layers were formed.

-Composition of the third layer forming coating solution-
An aqueous dispersion of composite particles of an ultraviolet absorber (triazine compound) and an acrylic resin (Tinuvin (registered trademark) 479-DW, manufactured by BASF, solid content 40% by mass)
... 3.5 parts Aqueous dispersion of acrylic resin as binder polymer (AS-563A, manufactured by Daicel Finechem Co., Ltd., latex having a styrene skeleton with a solid content of 28% by mass)
... 52.1 parts-Aqueous dispersion of olefin polymer (Arrowbase (registered trademark) SE-1013N, manufactured by Unitika Ltd., solid content 20.2% by mass)
... 8.0 parts-Water dilution of oxazoline-based crosslinking agent (Epocross (registered trademark) WS-700, manufactured by Nippon Shokubai Co., Ltd., solid content 25% by mass)
... 16.2 parts-water dilution of cross-linking catalyst (dibasic ammonium phosphate aqueous solution, solid content 35% by weight)
… 1.3 parts ・ Fluorine surfactant in water dilution [sodium bis (3,3,4,4,5,5,6,6,6-nonafluorohexyl) = 2-sulfonite oxysucci NART, manufactured by FUJIFILM Fine Chemical Co., Ltd., solid content: 2% by mass]
... 0.5 parts / water ... Remaining amount of 100 parts

[Formation of the fourth layer]
Next, the 4th layer formation coating liquid of the following composition was apply | coated to the surface of the 3rd layer, and the 4th layer of thickness 0.5 micrometer was formed by making it dry.

-Coating solution for forming the fourth layer-
・ Polyolefin resin aqueous dispersion (Arrowbase (registered trademark) SE-1013N, manufactured by Unitika Ltd., solid content 20% by mass)
17.5 parts of water diluted solution of oxazoline-based crosslinking agent (Epocross (registered trademark) WS-700, manufactured by Nippon Shokubai Co., Ltd., solid content: 25% by mass)
... 3.5 parts nonionic surfactant in water dilution (EMALEX (registered trademark) 110, manufactured by Nippon Emulsion Co., Ltd., solid content 10% by mass)
... 4.3 parts / water ... Remaining amount of 100 parts in total

  As described above, a base film in which an undercoat layer, a third layer, and a fourth layer are arranged in this order on the back surface (that is, a laminate having a laminate structure of base film / undercoat layer / third layer / fourth layer). Body substrate film was obtained.

[Formation of polymer layer (first layer)]
Next, a coating solution for forming a polymer layer having the following composition is applied to the front surface of the base film so that the solid content is 7.0 g / m ² and dried at 170 ° C. for 2 minutes. A polymer layer having a thickness of 7.0 μm was formed.

-Coating liquid for polymer layer formation-
Aqueous dispersion of siloxane-containing acrylic resin (Ceranate (registered trademark) WSA1070, manufactured by DIC Corporation, solid content: 38% by mass) (abbreviated as “WSA1070” in Table 1)
... 60 parts as a solid content. Water dilution of oxazoline-based crosslinking agent (Epocross (registered trademark) WS-700, manufactured by Nippon Shokubai Co., Ltd., solid content 25 mass%) (in Table 1, "WS-700" (Abbreviated)
... 40 parts as solid content-Water-diluted solution of fluorosurfactant [sodium = bis (3,3,4,4,5,5,6,6,6-nonafluorohexyl) = 2-sulfoniteoxys Cushinate, manufactured by Fuji Film Fine Chemical Co., Ltd., solid content: 2% by mass]
... 1.1 parts / water ... Remaining amount of 100 parts in total

In the composite particle of triazine compound and acrylic resin, which is a solid content of Tinuvin (registered trademark) 479-DW, the content of the triazine compound is 50% by mass with respect to the total mass of the composite particle.
The median diameter (D50) of the composite particles of the triazine compound and the acrylic resin, which is a solid content of Tinuvin (registered trademark) 479-DW, is less than 150 nm.

[Formation of hard coat layer]
Next, the hard coat layer-forming coating solution A prepared above is applied to the surface of the polymer layer and dried at 170 ° C. for 2 minutes, whereby a hard coat layer (second layer) having a thickness of 1 μm. Formed. Specifically, the hard coat layer (second layer) containing a siloxane resin that is a hydrolysis condensate of the alkoxysilane by condensing a hydrolyzate of the alkoxysilane (KBE-403 and KBE-04) by the drying. Formed.
Thus, a laminate having a laminate structure represented by hard coat layer (second layer) / polymer layer (first layer) / base film / undercoat layer / third layer / fourth layer was obtained.

<Uniformity of UV-absorbing compound concentration (uniformity in thickness direction of polymer layer)>
The uniformity of the UV-absorbing compound concentration in the solar cell front sheet obtained above was confirmed. The uniformity of the UV-absorbing compound concentration referred to here is uniformity in the thickness direction of the polymer layer.
Detailed operations are shown below.
Using a microtome, five thin film slices were prepared by dividing the polymer layer of the solar cell front sheet into five at equal intervals in the thickness direction.
Next, the transmittance at a wavelength of 325 nm was measured for each of the five thin film sections. The difference (absolute value) between the maximum value and the minimum value among the five measured values obtained was determined, and the uniformity of the UV-absorbing compound concentration was confirmed according to the following criteria.
The transmittance was measured using a spectrophotometer V670 (manufactured by JASCO Corporation). The results are shown in the “uniformity” column of Table 2.

[Standard for uniformity of UV-absorbing compound concentration]
A: The difference (absolute value) between the maximum value and the minimum value of transmittance at a wavelength of 325 nm was 30% or less of the maximum value, and the uniformity of the UV-absorbing compound concentration was excellent.
B: The difference between the maximum value and the minimum value of the transmittance at the maximum wavelength of 325 nm exceeded 30% of the maximum value, and the uniformity of the UV-absorbing compound concentration was poor.

<Measurement of pencil hardness of hard coat layer>
The pencil hardness of the surface of the laminate on the hard coat layer side was measured based on JIS K5600-5-4: 1999. A high uni from Mitsubishi Pencil Co., Ltd. was used as the pencil. The obtained measurement results (pencil hardness) were evaluated according to the following evaluation criteria. The evaluation results are shown in Table 2. In addition, the allowable range of pencil hardness is B or more, and preferably F or more.

〔Evaluation criteria〕
AA: The pencil hardness of the hard coat layer surface was “H” to “2H”.
A: The pencil hardness of the hard coat layer surface was “F”.
B: The pencil hardness of the hard coat layer surface was “HB”.
C: The pencil hardness of the hard coat layer surface was “B”.
D: The pencil hardness of the hard coat layer surface was “2B” or less.

<Crack after UV irradiation>
Based on the haze value after irradiating the laminated body with a metal halide lamp having an intensity of 90 mW / cm ^{2 at} a wavelength of 300 nm to 400 nm for 500 hours at 25 ° C., the crack after UV was evaluated. Specifically, it was measured based on JIS K7136 using a turbidimeter (NDH5000, Nippon Denshoku Industries Co., Ltd.) in an environment of 25 ° C. and a relative humidity of 60%. The obtained haze values were evaluated according to the following evaluation criteria and listed in Table 2. In addition, the tolerance | permissible_range of a haze value is less than 5.0, and it is preferable that it is less than 4.0.

〔Evaluation criteria〕
A: Haze value is less than 3.0 B: Haze value is 3.0 or more and less than 4.0 C: Haze value is 4.0 or more and less than 5.0 D: Haze value is 5.0 or more

<Adhesion>
The evaluation of the adhesion in the laminate was evaluated by a cross-cut tape adhesion test.
The surface of the laminate on the side of the hard coat layer was scratched by 11 in each direction at 1 mm intervals using a cutter to form 100 squares. A cellophane adhesive tape (cello tape (registered trademark) No. 405, 24 mm width, manufactured by Nichiban Co., Ltd.) was pasted thereon and quickly pulled in the vertical (90 °) direction to peel off. At this time, the adhesion of the laminate was evaluated according to the following evaluation criteria based on the total area of the peeled cells. The evaluation results are shown in Table 2. The allowable range of adhesion is C or more, preferably B or more.

〔Evaluation criteria〕
AAA: Peeling area is within 3% AA: Peeling area is greater than 3%, Peeling area is within 5% A: Peeling area is greater than 5% and is within 10% B: Peeling area is greater than 10% and is within 20% C: Peeling area is larger than 20% and within 40% D: Peeling area is larger than 40%

<Adhesion after UV irradiation>
After irradiating the laminate with a metal halide lamp with an intensity of 90 mW / cm ^{2 at} a wavelength of 300 nm to 400 nm at 63 ° C. and 50% Rh for 500 hours, an evaluation test similar to the above-described evaluation of adhesion was performed, Adhesion was evaluated. The evaluation criteria are the same as described above.

(Examples 2-36, Comparative Examples 1-3)
Each item was evaluated in the same manner as in Example 1 except that the hard coat layer forming coating solution, the thickness of the hard coat layer, and the composition of the polymer layer forming coating solution were changed as shown in Table 2.
In Table 2, the description in the column of addition amount means the solid content of each component relative to the solid content of each coating solution.
In Table 2, the description in the column of “Composition” indicates which of the above-mentioned coating liquids A to H for forming the hard coat layer was used, and an example in which the column of inorganic particles in Table 2 is described About, it shows that the inorganic particle described further was added to the coating liquid of the said coating liquid AH for hard-coat layer formation by the addition amount as described in a table | surface.

The meanings of the abbreviations in Table 2 other than those described above are as follows.
・ OZL-35 Silica particles (Snowtex (registered trademark) OZL-35, average particle size 100 nm, manufactured by Nissan Chemical Industries, Ltd., solid content 35.5% by mass)
WS-300: Compound having an oxazoline structure (Epocross (registered trademark) WS-300, manufactured by Nippon Shokubai Co., Ltd., solid content: 25% by mass)
WS-500: Compound having an oxazoline structure (Epocross (registered trademark) WS-500, manufactured by Nippon Shokubai Co., Ltd., solid content: 25% by mass)
APM: Melamine / formaldehyde resin (Beccamin APM, manufactured by DIC Corporation, solid content: 78% to 82%)
DZ-22E: polyfunctional aziridine compound (Chemite (registered trademark) DZ-22E, manufactured by Nippon Shokubai Co., Ltd., solid content: 29.0% to 33.0%)
-SE1013N: Polyolefin (PO) dispersion (Arrowbase (registered trademark), manufactured by Unitika Ltd., solid content 20% by mass)
AS563A: Acrylic resin (acrylic resin as a binder polymer) dispersion (AS-563A, manufactured by Daicel Finechem Co., Ltd., solid content: 28% by mass)
PS002: Styrene acrylic resin dispersion (Bonlon (registered trademark), manufactured by Mitsui Chemicals, solid content: 43% to 47%)
T479DW: Composite particles of ultraviolet absorber (triazine compound) and acrylic resin (Tinuvin (registered trademark) 479, manufactured by BASF, solid content 40% by mass)
UVA204W: aqueous dispersion of composite particles of UV absorber (benzotriazole compound) and acrylic resin (Newcoat (registered trademark) UVA204W, manufactured by Shin-Nakamura Chemical Co., Ltd.)

  The results of each Example and each Comparative Example are shown in Table 2.

  As shown in Table 2, in Examples 1 to 36 using a laminate having a polymer layer containing a compound having an oxazoline structure and a hard coat layer containing a siloxane resin on one surface of a substrate, a pencil A laminate having a hard coat layer excellent in hardness and suppressed from cracking after irradiation with ultraviolet rays was obtained.

  On the other hand, in Comparative Example 1 containing a melamine / formaldehyde resin instead of a compound having an oxazoline structure and Comparative Example 2 containing a polyfunctional aziridine compound, in any example, cracks after ultraviolet irradiation, It was inferior to adhesiveness and the adhesiveness after ultraviolet irradiation. This is because the formed laminate does not contain a compound having an oxazoline structure, so that the adhesiveness is inferior, and after irradiation with ultraviolet light, the reaction between silanol groups contained in the hard coat layer has progressed, so that cracking occurred. It is considered a thing.

  Moreover, in the comparative example 3 which does not contain an alkoxysilane compound but contains only an acrylic resin in the coating liquid for hard-coat layer formation, it was inferior to the pencil hardness of the obtained laminated body. This is presumably because the hardness of the hard coat layer is low.

(Examples 37 to 46)
Example 1 except that the coating liquid for forming the hard coat layer and the thickness of the hard coat layer were changed as shown in Table 3 and the polymer layer (first layer) was composed of two layers having different oxazoline contents. Each item was evaluated as described above.
Among the polymer layers, the layer corresponding to the upper layer (hard coat layer side layer) was described as the first layer (upper layer), and the layer corresponding to the lower layer (base material side layer) was referred to as the first layer (lower layer). For the first layer (upper layer) forming coating solution and the first layer (lower layer) forming coating solution, Table 3 or Table 4 shows the types and addition amounts of the compound having an oxazoline structure, the binder polymer, and the ultraviolet absorbing compound. The composition was the same as that of the coating liquid for forming a polymer layer of Example 1 except that the composition was changed as described above.

In addition, in the formation of the polymer layer (first layer), the laminate is prepared by applying a coating solution for forming the first layer (lower layer) on the substrate, followed by drying at 170 ° C. for 2 minutes, The same method as in Example 1 was performed except that the coating liquid for forming one layer (upper layer) was applied.
The coating amount of the first layer (upper layer) forming coating solution and the first layer (lower layer) forming coating solution is such that the thickness of each layer after drying becomes the thickness of each layer described in Table 3 or Table 4. did.
In Table 3 and Table 4, the description in the column of addition amount means the solid content of each component relative to the solid content of each coating solution.
In Table 3 and Table 4, the description in the column of “Composition” indicates which of the above-described coating liquids A to H for forming the hard coat layer was used, and is described in the column of inorganic particles in Table 2. About the example, it shows that the inorganic particle described further was added to the coating liquid of the said coating liquid AH for hard-coat layer formation with the addition amount as described in a table | surface.
The abbreviations in Table 3 and Table 4 are the same as the abbreviations in Table 2 above.

  The resulting laminate was evaluated for pencil hardness, cracks after UV irradiation, adhesion, and adhesion after UV irradiation in the same manner as in Example 1, and the evaluation results are shown in Table 4.

(Solar cell module)
Furthermore, when the solar cell module was produced using the laminate described in Example 35 as a solar cell front sheet, a solar cell module having excellent hardness of the hard coat layer and suppressing cracking of the hard coat layer was obtained. .
The solar cell module had excellent power generation efficiency even after irradiation with ultraviolet rays (irradiation of a metal halide lamp having a wavelength of 300 nm to 400 nm with an intensity of 90 mW / cm ² for 500 hours).

The disclosure of Japanese Patent Application No. 2017-072729 filed on March 31, 2017 and the disclosure of Japanese Patent Application No. 2017-134117 filed on July 7, 2017 are entirely Which is incorporated herein by reference.
All documents, patent applications, and technical standards described in this specification are the same as if each document, patent application, and technical standard were specifically and individually stated to be incorporated by reference. Which is incorporated herein by reference.

10 base film 11 polymer layer (first layer)
12 Hard coat layer (second layer)
13 Third Layer 14 Fourth Layer 20 Solar Cell Front Sheet 32 Solar Cell Element 34 Sealing Material 36 Element Structure 40 Solar Cell Back Sheet 50 Sunlight

Claims (17)

On one side of the substrate, it has a polymer layer containing a compound having an oxazoline structure, and a hard coat layer containing a siloxane resin,
The said siloxane resin contains the structural unit represented by following formula S1, and the structural unit represented by following formula S2.
[* -SiO _3/2 ] Formula S1
[SiO _4/2 ] Formula S2
In formula S1, * represents a binding site with another structure. However, the Si atom in Formula S1 is not directly bonded to the O atom at the bonding site.   The laminated body of Claim 1 whose total amount of the structure derived from the oxazoline structure and oxazoline structure contained in the said polymer layer is 3.7 mass%-22.1 mass% with respect to the total mass of a polymer layer.   The laminate according to claim 2, wherein the binder polymer is resin particles dispersed in a coating solution for forming a polymer layer.   In the siloxane resin, the molar amount of Si atoms in the structural unit represented by Formula S1 is 1.0 to 7.5 times the molar amount of Si atoms in the structural unit represented by Formula S2. The laminated body of any one of Claims 1-3.   In the siloxane resin, the molar amount of Si atoms in the structural unit represented by Formula S1 is 1.5 to 4.5 times the molar amount of Si atoms in the structural unit represented by Formula S2. The laminated body of any one of Claims 1-4.   The laminate according to any one of claims 1 to 5, wherein the polymer layer contains an ultraviolet absorbing compound.   The laminate according to claim 6, wherein the ultraviolet absorbing compound contains a compound having a triazine structure.   The laminate according to claim 6 or 7, wherein the ultraviolet absorbing compound is composite particles containing an acrylic resin and an ultraviolet absorber.   Five thin film sections obtained by dividing the polymer layer into five at equal intervals in the thickness direction were prepared, and the maximum value among the five measured values when the transmittance at a wavelength of 325 nm was measured for each of the five thin film sections. The laminate according to any one of claims 6 to 8, wherein a difference between the maximum value and the minimum value is 30% or less of the maximum value.   The laminate according to any one of claims 1 to 9, wherein the hard coat layer contains silica particles.   The laminated body of any one of Claims 1-10 whose thickness of the said hard-coat layer is 0.1 micrometer or more and 5 micrometers or less.   The laminate according to any one of claims 1 to 11, wherein the substrate is polyester. On at least one side of the substrate,
A polymer layer comprising a binder polymer;
A hard coat layer disposed on the surface of the polymer layer and containing a siloxane resin,
At 63 ° C. and a relative humidity of 50%, after irradiating a metal halide lamp with an intensity of a wavelength of 300 nm to 400 nm of 90 mW / cm ² for 500 hours, there is no crack of the hard coat layer,
As a result of performing a cross-cut adhesion test by the method described in JISK5600-5-6,
A laminate in which the area of the peeled portion is within 20%.   The laminated body as described in any one of Claims 1-13 whose said laminated body is a protection sheet for solar cells. An element structure including a solar cell element and a sealing material for sealing the solar cell element;
The laminated body according to any one of claims 1 to 14, which is disposed on a side where sunlight is incident on the element structure portion,
A solar cell backsheet disposed on the side opposite to the side on which sunlight is incident on the element structure;
A solar cell module. Preparing a substrate;
Preparing a coating solution for forming a polymer layer containing a binder polymer and a compound having an oxazoline structure;
Preparing a coating liquid for forming a hard coat layer containing a hydrolyzate of trifunctional alkoxysilane and a hydrolyzate of tetrafunctional alkoxysilane;
A step of applying a polymer layer-forming coating solution on one side of the substrate and drying to form a polymer layer; and
On the surface of the polymer layer, a coating liquid for forming a hard coat layer is applied and dried to contain a structural unit represented by the following formula S1 and a siloxane structure containing a structural unit represented by the following formula S2. Forming a hard coat layer. A method for manufacturing a laminate.
[* -SiO _3/2 ] Formula S1
[SiO _4/2 ] Formula S2
In formula S1, * represents a binding site with another structure. However, the Si atom in Formula S1 is not directly bonded to the O atom at the bonding site.   The total amount of the structure derived from the oxazoline structure and the oxazoline structure contained in the polymer layer is 3.7% by mass to 22.1% by mass with respect to the total mass of the polymer layer. Production method.