Adhesive resin composition, interlayer film for laminated glass, laminated glass, solar cell sealing material, and solar cell module

Abstract

To provide an adhesive resin composition having improved transparency and adhesiveness to a polyester resin layer.SOLUTION: An ethylene-unsaturated ester copolymer (A) and an epoxy group-containing ethylene-based copolymer (B) (provided that the ethylene-unsaturated ester copolymer (A) is excluded), in which a content of a constitutional unit derived from an unsaturated ester in the ethylene-unsaturated ester copolymer (A) is more than 20% by mass with respect to all constitutional units constituting the ethylene-unsaturated ester copolymer (A), (A) and a content (X1) of a constituent unit derived from ethylene with respect to an entire constituent unit constituting the epoxy group-containing ethylene-based polymer (B) is 10% by mass or less in terms of an absolute difference (X2 - X1) between the content (X2) of the constituent unit derived from ethylene with respect to the entire constituent unit constituting the ethylene-unsaturated ester polymer (A) and the content (LA) of the constituent unit derived from ethylene with respect to the entire constituent unit constituting the epoxy group-containing ethylene-based polymer (B).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an adhesive resin composition, an interlayer film for laminated glass, laminated glass, a solar cell encapsulant, and a solar cell module. [Background technology]

[0002] Laminated glass interlayers are used by being sandwiched between two pieces of glass. They are preferred for safety reasons, as they prevent fragments from scattering when the glass breaks and prevent the glass from collapsing due to the interlayer's self-supporting properties if the glass breaks.

[0003] Ionomer resins, for example, are used as materials for highly transparent laminated glass interlayers, and are characterized by excellent transparency and excellent adhesion to glass.

[0004] For example, Patent Document 1 describes an interlayer film for laminated glass, which is characterized by comprising an ionomer resin in which a binary copolymer of (A) ethylene and (B) (meth)acrylic acid or a (meth)acrylic acid acrylic ester is crosslinked with metal ions and has an MFR of 5 to 15 g / 10 min at 190°C x 2.16 kgf. Patent Document 1 also describes that such an interlayer film for laminated glass does not require a humidity control process (humidity adjustment process) and can be easily attached to glass sheets, yet provides sufficient adhesion to the glass sheets and excellent conformability to the glass sheets, maintains excellent toughness over a wide temperature range, is resistant to discoloration due to direct sunlight and ultraviolet rays, and combines excellent weather resistance and transparency.

[0005] Patent Document 2 describes a polymer sheet having a thickness of 10 mils (0.25 mm) or more and having at least one layer containing an ionomer or ionomer blend incorporating a partially neutralized α,β-ethylenically unsaturated carboxylic acid, wherein the ionomer or ionomer blend contains ions of one or more monovalent metals in an amount ranging from about 1 to about 60% and ions of one or more polyvalent metals in an amount ranging from about 40 to about 99%, based on the total amount of neutralization of the α,β-ethylenically unsaturated carboxylic acid. Patent Document 2 also describes that such a polymer sheet exhibits synergistically high adhesion to glass.

[0006] Patent Document 3 also describes a glass laminate including a thin glass sheet and an ionomer interlayer sheet, where the thin glass sheet has a thickness of 1.5 mm or less, and states that such a glass laminate has advantageous performance characteristics such as being lightweight, having a good impact adhesion level, good moisture resistance, and low stress. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-28486 [Patent Document 2] Special Publication No. 2009-512763 [Patent Document 3] Special Publication No. 2012-519646 Summary of the Invention [Problem to be solved by the invention]

[0008] In recent years, there has been an increasing need to place a decorated polyester resin layer between the glass and the laminated glass interlayer in order to impart design features to highly transparent laminated glass. However, while ionomers have excellent glass adhesion, they have poor adhesion to polyester resins, which has made it difficult in some cases to directly laminate a layer containing an ionomer (hereinafter also referred to as an "ionomer resin layer") and a polyester resin layer containing a polyester resin (hereinafter also referred to as a "polyester resin layer").

[0009] One method for laminating an ionomer resin layer and a polyester resin layer is to laminate a layer containing an adhesive resin composition between the ionomer resin layer and the polyester resin layer. However, adhesive resin compositions that have high adhesion to polyester resin layers do not have sufficient transparency, and laminating a layer containing such an adhesive resin composition between the ionomer resin layer and the polyester resin layer sometimes reduces the transparency of the laminated glass. Furthermore, since glass and polyester resin layers are also used in solar cell modules, there are cases where improved transparency and adhesion to the polyester resin layer are required for solar cell encapsulants for encapsulating solar cell elements in solar cell modules. That is, there has been a demand for an adhesive resin composition that has improved transparency and adhesiveness to polyester resin layers.

[0010] The present invention has been made in view of the above circumstances, and provides an adhesive resin composition having improved transparency and adhesion to a polyester resin layer, as well as a laminated glass interlayer, laminated glass, a solar cell encapsulant, and a solar cell module having improved transparency, adhesion to a polyester resin layer, and adhesion to glass. [Means for solving the problem]

[0011] According to the present invention, there are provided an adhesive resin composition, a laminated glass interlayer film, a laminated glass, a solar cell encapsulant, and a solar cell module, which are shown below.

[0012] [1] An ethylene-unsaturated ester copolymer (A) and an epoxy group-containing ethylene copolymer (B) (excluding the ethylene-unsaturated ester copolymer (A)), the content of structural units derived from unsaturated ester in the ethylene-unsaturated ester copolymer (A) is more than 20 mass% based on the total structural units constituting the ethylene-unsaturated ester copolymer (A); An adhesive resin composition, wherein the absolute value of the difference (X1-X2) between the content (X1) of structural units derived from ethylene relative to all structural units constituting the ethylene-unsaturated ester copolymer (A) and the content (X2) of structural units derived from ethylene relative to all structural units constituting the epoxy group-containing ethylene copolymer (B) is 10 mass% or less. [2] The adhesive resin composition according to [1], wherein the ethylene-unsaturated ester copolymer (A) has a melt flow rate of 1 g / 10 min or more and 100 g / 10 min or less, as measured in accordance with JIS K 7210:1999 at 190°C under a load of 2160 g. [3] The adhesive resin composition according to [1] or [2] above, wherein the ethylene-unsaturated ester copolymer (A) comprises an ethylene-vinyl acetate copolymer. [4] The adhesive resin composition according to any one of [1] to [3] above, wherein the epoxy group-containing ethylene copolymer (B) comprises at least one selected from the group consisting of ethylene-glycidyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-vinyl acetate copolymer, and ethylene-glycidyl (meth)acrylate-(meth)acrylic acid ester copolymer. [5] The adhesive resin composition according to any one of [1] to [4], wherein the content of structural units derived from ethylene in the epoxy group-containing ethylene copolymer (B) is 82 mass% or less based on all structural units constituting the epoxy group-containing ethylene copolymer (B). [6] The adhesive resin composition according to any one of [1] to [5] above, wherein the epoxy group-containing ethylene copolymer (B) has a Vicat softening point, as defined in JIS K 7206:1999, of 65°C or lower. [7] The adhesive resin composition according to any one of [1] to [6] above, wherein the epoxy group-containing ethylene copolymer (B) has a melting point of 90°C or lower as measured in accordance with JIS K 7121-1987. [8] The adhesive resin composition according to any one of [1] to [7] above, which has a haze of 10% or less as measured by the following method. (method) The adhesive resin composition is pressed under conditions of 140°C and 9.8 MPa, and then cooled under conditions of 20°C and 14.7 MPa to prepare a pressed sheet having a thickness of 3 mm. The haze of the obtained pressed sheet is then measured using a haze meter in accordance with JIS K 7136:2000. [9] The adhesive resin composition according to any one of [1] to [8] above, wherein the content of the ethylene-unsaturated ester copolymer (A) is 40% by mass or more and 99% by mass or less, when the total content of the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B) is taken as 100% by mass.

[10] The adhesive resin composition according to any one of [1] to [9], wherein the total content of the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B) is 70% by mass or more and 100% by mass or less, when the total amount of the adhesive resin composition is 100% by mass.

[11] The adhesive resin composition according to any one of [1] to

[10] above, which has a haze of 5% or less as measured by the following method. (method) A 3.2 mm thick glass sheet, a 1500 μm thick ionomer resin layer, a 100 μm thick sheet of the adhesive resin composition, and another 3.2 mm thick glass sheet are laminated in this order and bonded together at a heating temperature of 140°C, a heating pressure of 1 atm, and a heating time of 20 minutes. The glass laminate is then slowly cooled by natural cooling to produce a glass laminate for optical property evaluation. The haze of the resulting glass laminate is then measured using a haze meter in accordance with JIS K 7136:2000.

[12] The adhesive resin composition according to any one of [1] to

[11] above, wherein the adhesive strength to a PET film measured by the following method is 15 N / 15 mm or more at the initial stage, after 500 hours, and after 1000 hours. (method) A 3.9 mm thick glass sheet (with the non-tin side facing the adhesive surface), a 300 μm thick sheet made of the adhesive resin composition, and a 100 μm thick PET film (not corona-treated) were laminated in this order and heated at 140°C under a heating pressure of 1 atm for 60 minutes to produce a glass laminate. The glass laminate was then left standing in the air and allowed to cool naturally. A 15 mm wide slit was cut into the sheet portion of the resulting glass laminate to prepare a test specimen, which was then placed in a tensile tester. The PET film was peeled off at a tensile speed of 100 mm / min and a peel angle of 180°, and the average stress was measured as the initial adhesive strength (N / 15 mm). The glass laminate was then stored at 85°C and 90% relative humidity, and the adhesive strength of the glass laminate was measured after 500 hours of storage and after 1000 hours of storage.

[13] The adhesive resin composition according to any one of [1] to

[12] above, which has an adhesive strength to a PET film of 50 N / 15 mm or more after storage for 1000 hours, as measured by the following method. (method) A 3.9 mm thick glass sheet (with the non-tin side as the adhesive surface), a 300 μm thick sheet made of the adhesive resin composition, and a 100 μm thick PET film (not corona-treated) were laminated in this order and heated to 140°C under a heating pressure of 1 atm for 60 minutes to produce a glass laminate. The glass laminate was then left to stand in the air and slowly cooled by natural cooling. The glass laminate was then stored for 1000 hours at 85°C and 90% relative humidity. A 15 mm wide slit was made in the sheet portion of the resulting glass laminate to prepare a test specimen, which was then placed in a tensile tester. The PET film was peeled off at a tensile speed of 100 mm / min and a peel angle of 180°, and the average stress was measured as the adhesive strength (N / 15 mm) to the PET film after 1000 hours of storage.

[14] A laminated glass interlayer film comprising an adhesive resin layer containing the adhesive resin composition according to any one of [1] to

[13] above.

[15] an ionomer resin layer containing an ionomer (C) of an ethylene-unsaturated carboxylic acid copolymer; an adhesive resin layer containing the adhesive resin composition according to any one of [1] to

[13] above; a polyester resin layer containing a polyester resin (D); A laminated glass interlayer film comprising:

[16] the ionomer resin layer and the adhesive resin layer are adjacent to each other,

[16] The laminated glass interlayer film according to

[15] , wherein the polyester resin layer is adjacent to a surface of the adhesive resin layer opposite to a surface of the adhesive resin layer adjacent to the ionomer resin layer.

[17] The laminated glass interlayer film according to any one of

[14] to

[16] above, transparent plate-like members provided on both sides of the laminated glass interlayer; Laminated glass comprising:

[18] The laminated glass according to

[17] above, which includes at least one configuration in which the transparent plate-like member and the ionomer resin layer are adjacent to each other.

[19] A solar cell encapsulant comprising an adhesive resin layer containing the adhesive resin composition according to any one of [1] to

[13] above.

[20] a solar cell element; an encapsulating resin for encapsulating the solar cell element, the encapsulating resin being made of the solar cell encapsulant material according to

[19] ; A solar cell module comprising: [Effects of the Invention]

[0013] According to the present invention, it is possible to provide an adhesive resin composition having improved transparency and adhesion to a polyester resin layer, as well as a laminated glass interlayer, laminated glass, a solar cell encapsulant, and a solar cell module having improved transparency, adhesion to a polyester resin layer, and adhesion to glass. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, the present invention will be described based on embodiments. In this specification, unless otherwise specified, "A to B" indicating a numerical range means A or more and B or less. Furthermore, "(meth)acrylic acid" means "at least one selected from the group consisting of acrylic acid and methacrylic acid," and "(meth)acrylate" means "at least one selected from the group consisting of acrylate and methacrylate."

[0015] 1.Adhesive resin composition The adhesive resin composition of the present invention comprises an ethylene-unsaturated ester copolymer (A) (hereinafter also referred to as "copolymer (A)") and an epoxy group-containing ethylene copolymer (B) (hereinafter also referred to as "copolymer (B)"), wherein the content of structural units derived from unsaturated esters in the ethylene-unsaturated ester copolymer (A) is greater than 20 mass% based on all structural units constituting the ethylene-unsaturated ester copolymer (A), and the absolute value of the difference (X1-X2) between the content (X1) of structural units derived from ethylene based on all structural units constituting the ethylene-unsaturated ester copolymer (A) and the content (X2) of structural units derived from ethylene based on all structural units constituting the epoxy group-containing ethylene copolymer (B) (hereinafter also referred to as "ethylene content difference") is 10 mass% or less, with the proviso that the ethylene-unsaturated ester copolymer (A) is excluded from the epoxy group-containing ethylene copolymer (B).

[0016] The adhesive resin composition according to the present invention can improve transparency and adhesion to a polyester resin layer. Furthermore, the adhesive resin composition according to the present invention can realize a laminated glass interlayer, laminated glass, a solar cell encapsulant, and a solar cell module that have improved transparency, adhesion to a polyester resin layer, and adhesion to glass. The reason why such an effect is obtained is presumed to be as follows. First, it is believed that the combination of the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B) can improve adhesion to a polyester resin layer. Furthermore, it is believed that by controlling the content of structural units derived from unsaturated esters in the ethylene-unsaturated ester copolymer (A) to be equal to or greater than the lower limit, the crystallinity of the ethylene-unsaturated ester copolymer (A) can be reduced. Furthermore, by controlling the ethylene content difference to be equal to or less than the upper limit, the compatibility between the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B) can be improved. Furthermore, it is believed that the difference in refractive index between the copolymers can be reduced, thereby improving transparency.

[0017] In the adhesive resin composition of the present invention, the ethylene content difference is 10% by mass or less, but from the viewpoint of further improving transparency and adhesion to the polyester resin layer, it is preferably 8% by mass or less, more preferably 6% by mass or less, even more preferably 4% by mass or less, even more preferably 3% by mass or less, and preferably 0% by mass or more.

[0018] When the total content of the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B) in the adhesive resin composition according to the present invention is taken as 100% by mass, the content of the ethylene-unsaturated ester copolymer (A) is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 50% by mass or more, from the viewpoint of further improving transparency, adhesion to a polyester resin layer, and processability, and is preferably 99% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less, from the viewpoint of further improving transparency, adhesion to a polyester resin layer, and processability.

[0019] The total content of the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B) in the adhesive resin composition according to the present invention, when the entire adhesive resin composition is taken as 100% by mass, is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and preferably 100% by mass or less, from the viewpoint of further improving transparency and adhesion to a polyester resin layer.

[0020] Each component constituting the adhesive resin composition according to the present invention will be described below.

[0021] <Ethylene-unsaturated ester copolymer (A)> The ethylene-unsaturated ester copolymer (A) is a polymer obtained by copolymerizing ethylene with at least one unsaturated ester. Examples of the ethylene-unsaturated ester copolymer (A) include copolymers containing ethylene and an unsaturated ester. The ethylene-unsaturated ester copolymer (A) preferably contains at least one polymer selected from the group consisting of ethylene-vinyl ester copolymers and ethylene-unsaturated carboxylic acid ester copolymers. The ethylene-unsaturated ester copolymer (A) may contain a polymerizable monomer other than ethylene and the unsaturated ester, for example, an olefin such as propylene, butene, or hexene.

[0022] As the ethylene-vinyl ester copolymer, for example, at least one selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, ethylene-vinyl butyrate copolymer, and ethylene-vinyl stearate copolymer can be used.

[0023] Ethylene-unsaturated carboxylic acid ester copolymer is a polymer obtained by copolymerizing ethylene with at least one unsaturated carboxylic acid ester. Specifically, a copolymer made of ethylene and an unsaturated carboxylic acid alkyl ester can be exemplified.

[0024] As the unsaturated carboxylic acid in the unsaturated carboxylic acid ester, for example, at least one selected from the group consisting of acrylic acid, methacrylic acid, 2-ethylacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, monomethyl maleate, monoethyl maleate, and the like can be used. Among these, the unsaturated carboxylic acid preferably includes at least one selected from the group consisting of acrylic acid and methacrylic acid, from the viewpoint of improving the productivity and sanitation of the ethylene-unsaturated ester copolymer (A).

[0025] Examples of the alkyl moiety in the unsaturated carboxylic acid alkyl ester include those having 1 to 12 carbon atoms, and more specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, 2-ethylhexyl, and isooctyl. In this embodiment, the number of carbon atoms in the alkyl moiety of the alkyl ester is preferably 1 to 8, and more preferably 1 to 4.

[0026] The unsaturated carboxylic acid ester preferably includes at least one selected from the group consisting of (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, isobutyl (meth)acrylate, n-butyl (meth)acrylate, isooctyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. These unsaturated carboxylic acid esters may be used alone or in combination of two or more. Among these, it is more preferable to include at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, isobutyl (meth)acrylate, and n-butyl (meth)acrylate.

[0027] In this embodiment, the preferred ethylene-unsaturated carboxylic acid ester copolymer is an ethylene-(meth)acrylic acid ester copolymer. Among them, a copolymer consisting of one type of (meth)acrylic acid ester compound is preferred. Examples of such copolymers include at least one selected from the group consisting of ethylene-methyl (meth)acrylate copolymer, ethylene-ethyl (meth)acrylate copolymer, ethylene-isopropyl (meth)acrylate copolymer, ethylene-n-propyl (meth)acrylate copolymer, ethylene-isobutyl (meth)acrylate copolymer, ethylene-n-butyl (meth)acrylate copolymer, ethylene-isooctyl (meth)acrylate copolymer, and ethylene-2-ethylhexyl (meth)acrylate copolymer.

[0028] The ethylene-unsaturated ester copolymer (A) preferably contains at least one selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-methyl (meth)acrylate copolymer, ethylene-ethyl (meth)acrylate copolymer, ethylene-isopropyl (meth)acrylate copolymer, ethylene-n-propyl (meth)acrylate copolymer, ethylene-isobutyl (meth)acrylate copolymer, and ethylene-n-butyl (meth)acrylate copolymer, more preferably contains ethylene-vinyl acetate copolymer, and even more preferably is ethylene-vinyl acetate copolymer. In the present embodiment, the ethylene-unsaturated ester copolymer (A) may be used alone or in combination of two or more kinds.

[0029] The melt flow rate (MFR) of the ethylene-unsaturated ester copolymer (A), measured in accordance with JIS K 7210:1999 at 190°C under a load of 2160 g, is preferably 1 g / 10 min or more, more preferably 10 g / 10 min or more, even more preferably 11 g / 10 min or more, even more preferably 12 g / 10 min or more, and still more preferably 13 g / 10 min or more, from the viewpoint of further improving transparency and adhesion to the polyester resin layer; and is preferably 100 g / 10 min or less, more preferably 50 g / 10 min or less, even more preferably 30 g / 10 min or less, even more preferably 20 g / 10 min or less, even more preferably 18 g / 10 min or less, and still more preferably 15 g / 10 min or less, from the viewpoint of further improving the heat resistance, mechanical strength, transparency, etc. of the resulting laminated glass interlayer film or solar cell encapsulant. The MFR of the ethylene-unsaturated ester copolymer (A) may be adjusted by blending multiple ethylene-unsaturated ester copolymers (A) having different MFRs. When multiple ethylene-unsaturated ester copolymers (A) having different MFRs are blended, the MFR of the blend is taken as the MFR of the ethylene-unsaturated ester copolymer (A).

[0030] The content of structural units derived from ethylene in the ethylene-unsaturated ester copolymer (A) is preferably 50% by mass or more, more preferably 55% by mass or more, even more preferably 60% by mass or more, and even more preferably 65% ​​by mass or more, relative to all structural units constituting the ethylene-unsaturated ester copolymer (A), from the viewpoint of further improving heat resistance, mechanical strength, water resistance, processability, productivity, etc., and is preferably 80% by mass or less, more preferably 76% by mass or less, even more preferably 73% by mass or less, even more preferably 70% by mass or less, and even more preferably 68% by mass or less, from the viewpoint of further improving transparency, flexibility, and adhesion to the polyester resin layer.

[0031] The content of structural units derived from unsaturated esters in the ethylene-unsaturated ester copolymer (A) is more than 20% by mass based on all structural units constituting the ethylene-unsaturated ester copolymer (A). From the viewpoint of further improving transparency, flexibility, and adhesion to the polyester resin layer, the content is preferably 24% by mass or more, more preferably 27% by mass or more, even more preferably 30% by mass or more, and still more preferably 32% by mass or more; and from the viewpoint of further improving heat resistance, mechanical strength, water resistance, processability, productivity, etc., the content is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less, and still more preferably 35% by mass or less. When the unsaturated ester is vinyl acetate, the content of the structural unit derived from the unsaturated ester can be measured, for example, in accordance with JIS K 7192:1999. When the unsaturated ester is an unsaturated carboxylic acid ester, the content of the structural unit derived from the unsaturated ester can be measured, for example, by infrared absorption spectroscopy (IR) attributable to the unsaturated carboxylic acid ester. For example, when the unsaturated carboxylic acid ester is ethyl acrylate (EA), the content of the structural unit derived from the unsaturated ester can be measured by infrared absorption spectroscopy (IR) at 860 cm -1 However, the calibration curve is based on the EA concentration determined by nuclear magnetic resonance spectroscopy (NMR) and the 860 cm -1 It is calculated by correlation with the absorbance of

[0032] The method for producing the ethylene-unsaturated ester copolymer (A) is not particularly limited, and it can be produced by a known method. For example, it can be obtained by radical copolymerization of each polymerization component under high temperature and high pressure. Alternatively, commercially available ethylene-unsaturated ester copolymer (A) may be used.

[0033] From the viewpoint of further improving adhesiveness, it is preferred that at least a portion of the ethylene-unsaturated ester copolymer (A) is modified with a silane coupling agent. Here, the silane coupling agent in the ethylene-unsaturated ester copolymer (A) preferably includes at least one selected from the group consisting of a silane coupling agent having a polymerizable group, a silane coupling agent having an amino group, and a silane coupling agent having an epoxy group. From the viewpoint of further improving adhesiveness, the content of the silane coupling agent is preferably 0.02 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.5 parts by mass or more, and is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, even more preferably 3 parts by mass or less, relative to 100 parts by mass of the ethylene-unsaturated ester copolymer (A).

[0034] Here, the ethylene-unsaturated ester copolymer (A) can be modified with a silane coupling agent by, for example, the same method as that used to modify the epoxy group-containing ethylene copolymer (B) described below with a silane coupling agent. Alternatively, modification of the ethylene-unsaturated ester copolymer (A) with a silane coupling agent and modification of the epoxy group-containing ethylene copolymer (B) with a silane coupling agent may be carried out simultaneously. When the modification of the ethylene-unsaturated ester copolymer (A) with a silane coupling agent and the modification of the epoxy group-containing ethylene copolymer (B) with a silane coupling agent are carried out simultaneously, the content of the polymerization initiator used for the modification is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.2 parts by mass or more, and is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 1.5 parts by mass or less, even more preferably 1 part by mass or less, even more preferably 0.3 parts by mass or less, per 100 parts by mass of the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B) in total. From the viewpoint of further improving adhesiveness, the content of the silane coupling agent is preferably 0.02 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.5 parts by mass or more, relative to 100 parts by mass in total of the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B), and is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, even more preferably 3 parts by mass or less, and even more preferably 1.5 parts by mass or less.

[0035] <Epoxy group-containing ethylene copolymer (B)> Examples of the epoxy group-containing ethylene copolymer (B) include glycidyl group-containing ethylene copolymers. From the viewpoint of further improving transparency and adhesion to the polyester resin layer, the glycidyl group-containing ethylene copolymer is preferably at least one selected from the group consisting of ethylene-glycidyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-vinyl acetate copolymer, and ethylene-glycidyl (meth)acrylate-(meth)acrylic acid ester copolymer, more preferably ethylene-glycidyl (meth)acrylate-(meth)acrylic acid ester copolymer, even more preferably ethylene-glycidyl (meth)acrylate-methyl (meth)acrylate copolymer, and even more preferably ethylene-glycidyl methacrylate-methyl acrylate copolymer.

[0036] The epoxy group-containing ethylene copolymer (B) can be obtained by copolymerizing a monomer having a polymerizable group and an epoxy group, such as glycidyl (meth)acrylate (hereinafter also referred to as "glycidyl (meth)acrylate"), vinyl glycidyl ether, 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexylmethyl methacrylate, etc., with ethylene. Alternatively, the epoxy group can be introduced by graft polymerizing a monomer having an epoxy group onto the ethylene copolymer.

[0037] The content of structural units derived from monomers having epoxy groups in the epoxy group-containing ethylene copolymer (B) is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, and even more preferably 3% by mass or more, relative to all structural units constituting the epoxy group-containing ethylene copolymer (B), from the viewpoint of further improving adhesiveness, transparency, and flexibility, and is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 8% by mass or less, and even more preferably 6% by mass or less, from the viewpoint of further improving processability. The term "glycidyl (meth)acrylate" refers to at least one selected from the group consisting of glycidyl methacrylate and glycidyl acrylate.

[0038] The term "ethylene copolymer" in the epoxy group-containing ethylene copolymer (B) refers to a copolymer in which ethylene-derived structural units are the main component. Furthermore, the term "main component" here refers to a copolymer in which the content of "ethylene-derived structural units" is the highest among all structural units. For example, in the case of a copolymer consisting of structural units derived from ethylene, glycidyl (meth)acrylate, and vinyl acetate, the ratio of ethylene-derived structural units is greater than that of the structural units derived from glycidyl (meth)acrylate and the structural units derived from vinyl acetate. The content of structural units derived from ethylene in the epoxy group-containing ethylene copolymer (B) is preferably 50% by mass or more, more preferably 55% by mass or more, even more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, and even more preferably 67% by mass or more, based on all structural units constituting the epoxy group-containing ethylene copolymer (B), from the viewpoint of improving productivity, and is preferably 82% by mass or less, more preferably 80% by mass or less, even more preferably 78% by mass or less, even more preferably 75% by mass or less, even more preferably 72% by mass or less, and even more preferably 70% by mass or less, from the viewpoint of further improving transparency and adhesion to the polyester resin layer.

[0039] The epoxy group-containing ethylene copolymer (B) may further contain other monomer units in addition to ethylene and the monomer having an epoxy group. Examples of other monomers include vinyl esters such as vinyl acetate and vinyl propionate, and unsaturated carboxylic acid esters such as acrylic acid esters, methacrylic acid esters, ethacrylic acid esters, crotonates, fumarates, maleates, maleic anhydride esters, itaconic acid esters, and itaconic anhydride esters. Examples of the ester group include alkyl ester groups having from 1 to 12 carbon atoms, and more specific examples include alkyl ester groups such as methyl ester, ethyl ester, n-propyl ester, isopropyl ester, n-butyl ester, isobutyl ester, secondary butyl ester, 2-ethylhexyl ester, and isooctyl ester. Among these, at least one selected from the group consisting of vinyl acetate and (meth)acrylic acid esters is preferred.

[0040] Specifically, examples include copolymers containing a structural unit derived from ethylene and a structural unit derived from glycidyl (meth)acrylate, as well as copolymers containing, in addition to these two structural units, at least one structural unit selected from the group consisting of a structural unit derived from vinyl acetate and a structural unit derived from a (meth)acrylic acid ester.

[0041] The content of structural units derived from monomers other than ethylene and monomers having an epoxy group in the epoxy group-containing ethylene copolymer (B) relative to all structural units constituting the epoxy group-containing ethylene copolymer (B), from the viewpoint of further improving transparency and adhesion to glass or polyester resin layers, is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 20% by mass or more, even more preferably 25% by mass or more, even more preferably 26% by mass or more, and is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, even more preferably 29% by mass or less, and even more preferably 28% by mass or less.

[0042] The epoxy group-containing ethylene copolymer (B) may be used alone or in combination of two or more.

[0043] At least a part of the epoxy group-containing ethylene copolymer (B) is preferably modified with a silane coupling agent from the viewpoint of further improving the adhesiveness to glass or polyester resin layers.

[0044] Here, in the adhesive resin composition according to the present invention, it is preferable that the silane coupling agent in the epoxy group-containing ethylene copolymer (B) contains at least one selected from the group consisting of a silane coupling agent having a polymerizable group, a silane coupling agent having an amino group, and a silane coupling agent having an epoxy group. Here, the modification of the epoxy group-containing ethylene copolymer (B) with a silane coupling agent can be performed, for example, by reacting the epoxy group-containing ethylene copolymer (B) with a silane coupling agent having an amino group or an epoxy group under heating (for example, at 100°C or higher and 200°C or lower) (modification method 1), or by graft polymerizing the epoxy group-containing ethylene copolymer (B) with a silane coupling agent having a polymerizable group using a polymerization initiator (modification method 2). In modification method 1, the amino group or epoxy group in the silane coupling agent reacts with the glycidyl group in the epoxy group-containing ethylene copolymer (B), thereby introducing the silane coupling agent into the side chain of the epoxy group-containing ethylene copolymer (B). In modification method 2, for example, the epoxy group-containing ethylene copolymer (B), a silane coupling agent having a polymerizable group, and a radical polymerization initiator are melt-kneaded at a temperature equal to or higher than the melting point of the epoxy group-containing ethylene copolymer (B) and equal to or higher than the decomposition temperature of the radical polymerization initiator using an extruder, kneader, Banbury mixer, etc. These reactions can also be carried out in solution.

[0045] As the polymerization initiator, any of those commonly used can be used, but organic peroxides are preferred. As the organic peroxide, known organic peroxides that can be used as a polymerization initiator can be used, and specific examples thereof include diacyl peroxide compounds, alkyl peroxy ester compounds, peroxydicarbonate compounds, peroxycarbonate compounds, peroxyketal compounds, dialkyl peroxide compounds, hydroperoxide compounds, and ketone peroxide compounds. Among these, dialkyl peroxide compounds are preferred, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-di(2-t-butylperoxyisopropyl)benzene, di-t-butyl peroxide, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3 are more preferred.

[0046] Examples of silane coupling agents having a polymerizable group include vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, and 3-acryloxypropyltriethoxysilane. Examples of silane coupling agents having an amino group include N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride. Examples of silane coupling agents having an epoxy group include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane.

[0047] From the viewpoint of further improving the adhesion to glass or a polyester resin layer, the content of the polymerization initiator used for modification is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less, even more preferably 1.0 part by mass or less, and even more preferably 0.6 part by mass or less, relative to 100 parts by mass of the epoxy group-containing ethylene copolymer (B). From the viewpoint of further improving adhesion to glass and polyester resin layers, the content of the silane coupling agent is preferably 0.02 parts by mass or more and preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less, per 100 parts by mass of the epoxy group-containing ethylene copolymer (B).

[0048] The Vicat softening point of the epoxy group-containing ethylene copolymer (B), as defined in JIS K 7206:1999, is preferably 65°C or lower, more preferably 50°C or lower, even more preferably 40°C or lower, even more preferably 30°C or lower, and even more preferably 25°C or lower, from the viewpoint of further improving adhesion to glass and polyester resin layers, and is preferably 20°C or higher from the viewpoint of heat resistance and processability.

[0049] The melting point of the epoxy group-containing ethylene copolymer (B), measured in accordance with JIS K 7121-1987, is preferably 90°C or lower, more preferably 80°C or lower, even more preferably 70°C or lower, even more preferably 65°C or lower, and even more preferably 60°C or lower, from the viewpoint of further improving adhesion to glass and polyester resin layers, and is preferably 30°C or higher, more preferably 40°C or higher, even more preferably 45°C or higher, and even more preferably 52°C or higher, from the viewpoint of heat resistance and processability.

[0050] The melt flow rate (MFR) of the epoxy group-containing ethylene copolymer (B), measured in accordance with JIS K 7210:1999 under conditions of 190°C and a load of 2160 g, is preferably 0.1 g / 10 min or more, more preferably 1 g / 10 min or more, even more preferably 2 g / 10 min or more, even more preferably 3 g / 10 min or more, even more preferably 4 g / 10 min or more, and is preferably 100 g / 10 min or less, more preferably 50 g / 10 min or less, even more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, from the viewpoint of further improving processing stability.

[0051] <Other ingredients> The adhesive resin composition of the present invention may contain components other than the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B), provided that the components do not impair the objectives of the present invention. These other components are not particularly limited, but examples include plasticizers, antioxidants, ultraviolet absorbers, wavelength conversion agents, antistatic agents, surfactants, colorants, light stabilizers, foaming agents, lubricants, crystal nucleating agents, crystallization accelerators, crystallization retarders, catalyst deactivators, heat absorbers, heat reflectors, heat dissipation agents, thermoplastic resins, thermosetting resins, inorganic fillers, organic fillers, impact modifiers, slip agents, crosslinking agents, crosslinking aids, silane coupling agents, tackifiers, processing aids, mold release agents, hydrolysis inhibitors, heat stabilizers, antiblocking agents, antifogging agents, flame retardants, flame retardant aids, light diffusing agents, antibacterial agents, antifungal agents, dispersants, and other resins. These other components may be used singly or in combination.

[0052] From the viewpoint of further improving transparency, the adhesive resin composition according to the present invention preferably has a haze measured by the following method of 10% or less, more preferably 9% or less, and even more preferably 8.4% or less. (method) The adhesive resin composition is pressed under conditions of 140°C and 9.8 MPa, and then cooled under conditions of 20°C and 14.7 MPa to prepare a pressed sheet having a thickness of 3 mm. The haze of the obtained pressed sheet is then measured using a haze meter in accordance with JIS K 7136:2000.

[0053] From the viewpoint of further improving the transparency of the resulting laminated glass or solar cell module, the adhesive resin composition according to the present invention preferably has a haze measured by the following method of 5% or less, more preferably 4% or less, and even more preferably 3.0% or less. (method) A 3.2 mm thick glass sheet, a 1500 μm thick ionomer resin layer, a 100 μm thick sheet of the adhesive resin composition, and another 3.2 mm thick glass sheet are laminated in this order and bonded together at a heating temperature of 140°C, a heating pressure of 1 atm, and a heating time of 20 minutes. The glass laminate is then slowly cooled by natural cooling to produce a glass laminate for optical property evaluation. The haze of the resulting glass laminate is then measured using a haze meter in accordance with JIS K 7136:2000.

[0054] From the viewpoint of further improving the adhesion to the polyester resin layer, the adhesive resin composition according to the present invention has an adhesive strength to a PET film, measured by the following method, initially, after 500 hours, and after 1000 hours, of preferably 15 N / 15 mm or more, more preferably 18 N / 15 mm or more, and even more preferably 20 N / 15 mm or more. (method) A 3.9 mm thick glass sheet (with the non-tin side as the adhesive surface), a 300 μm thick sheet made of the adhesive resin composition, and a 100 μm thick PET film (not corona-treated) were laminated in this order and heated at 140°C under a heating pressure of 1 atm for 60 minutes to produce a glass laminate. The glass laminate was then left standing in the air and allowed to cool naturally. A 15 mm wide slit was made in the sheet portion of the resulting glass laminate to prepare a test specimen, which was then placed in a tensile tester. The PET film was peeled off at a tensile speed of 100 mm / min and a peel angle of 180°, and the average stress was determined as the initial adhesive strength (N / 15 mm). Here, the average stress refers to the average value of the stress measured while peeling off the PET film. The glass laminate was then stored at 85°C and 90% relative humidity, and the adhesive strength of the glass laminate was measured after 500 hours of storage and after 1000 hours of storage.

[0055] From the viewpoint of further improving the adhesion to the polyester resin layer, the adhesive resin composition according to the present invention has an adhesive strength to a PET film after storage for 1000 hours, measured by the method described below, of preferably 50 N / 15 mm or more, more preferably 70 N / 15 mm or more, even more preferably 85 N / 15 mm or more, and still more preferably 89.6 N / 15 mm or more. (method) A 3.9 mm thick glass sheet (with the non-tin side as the adhesive surface), a 300 μm thick sheet made of the adhesive resin composition, and a 100 μm thick PET film (not corona-treated) were laminated in this order and heated to 140°C under a heating pressure of 1 atm for 60 minutes to produce a glass laminate. The glass laminate was then left to stand in the air and slowly cooled by natural cooling. The glass laminate was then stored for 1000 hours at 85°C and 90% relative humidity. A 15 mm wide slit was made in the sheet portion of the resulting glass laminate to prepare a test specimen, which was then placed in a tensile tester. The PET film was peeled off at a tensile speed of 100 mm / min and a peel angle of 180°, and the average stress was measured as the adhesive strength (N / 15 mm) to the PET film after 1000 hours of storage.

[0056] 2. Laminated glass interlayer The laminated glass interlayer film of the present invention includes an adhesive resin layer containing the adhesive resin composition of the present invention. The laminated glass interlayer film according to the present invention may have a single layer structure or a multi-layer structure of two or more layers. More specifically, the laminated glass interlayer film according to the present invention may be a single-layer film made of one adhesive resin layer, a multilayer film made of two or more adhesive resin layers, or a multilayer film having at least one adhesive resin layer and at least one layer other than the adhesive resin layer.

[0057] From the viewpoint of further improving the adhesive strength and design, the thickness of the adhesive resin layer is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, even more preferably 30 μm or more, even more preferably 50 μm or more, and even more preferably 75 μm or more, and from the viewpoint of improving the transparency and heat resistance of the obtained laminated glass or solar cell module, the thickness is preferably 2000 μm or less, more preferably 1500 μm or less, even more preferably 1000 μm or less, even more preferably 500 μm or less, and even more preferably 400 μm or less.

[0058] From the viewpoint of further improving transparency and adhesion to glass, the laminated glass interlayer film of the present invention preferably has a multilayer structure including an ionomer resin layer containing the ionomer (C) of an ethylene-unsaturated carboxylic acid copolymer and an adhesive resin layer containing the adhesive resin composition of the present invention. When the laminated glass interlayer film according to the present invention has a multilayer structure including an ionomer resin layer and an adhesive resin layer, it may have a two-layer structure including an ionomer resin layer and an adhesive resin layer, or a three-layer structure including an ionomer resin layer and two adhesive resin layers formed on both sides of the ionomer resin layer so as to sandwich the ionomer resin layer. When the laminated glass interlayer film according to the present invention has a multilayer structure including an ionomer resin layer and an adhesive resin layer, the thickness ratio (a / b) of the ionomer resin layer (thickness a) to the adhesive resin layer (thickness b) is preferably 3 / 1 or more and 80 / 1 or less, more preferably 7 / 1 or more and 30 / 1 or less, from the viewpoint of further improving adhesion to glass and transparency.

[0059] From the viewpoint of further improving adhesion to glass, transparency, interlayer adhesion, and designability, the laminated glass interlayer film of the present invention more preferably has a multilayer structure including, in this order: an ionomer resin layer containing an ionomer (C) of an ethylene-unsaturated carboxylic acid copolymer; an adhesive resin layer containing the adhesive resin composition of the present invention; and a polyester resin layer containing a polyester resin (D). When the laminated glass interlayer film according to the present invention has a multilayer structure including an ionomer resin layer, an adhesive resin layer according to the present invention, and a polyester resin layer in this order, from the viewpoint of further improving the interlayer adhesion of the laminated glass interlayer film according to the present invention, it is preferable that the ionomer resin layer and the adhesive resin layer according to the present invention are adjacent to each other, and that the polyester resin layer is adjacent to the surface of the adhesive resin layer according to the present invention opposite to the surface adjacent to the ionomer resin layer.

[0060] When the laminated glass interlayer film according to the present invention has a multilayer structure including an ionomer resin layer, an adhesive resin layer, and a polyester resin layer, the thickness ratio (a / b) of the ionomer resin layer (thickness a) to the adhesive resin layer (thickness b) is preferably 3 / 1 or more and 80 / 1 or less, more preferably 7 / 1 or more and 30 / 1 or less, from the viewpoint of further improving adhesion and transparency.

[0061] <Ionomer resin layer> The ionomer resin layer contains an ionomer (C) of an ethylene-unsaturated carboxylic acid copolymer (hereinafter also referred to as "ionomer (C)"), and preferably contains the ionomer (C) as a main component. Here, the term "main component" means that the ionomer (C) is contained in the ionomer resin layer in an amount of 50% by mass or more. The content of the ionomer (C) in the ionomer resin layer is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, from the viewpoint of further improving adhesion to glass, when the entire ionomer resin layer is taken as 100% by mass. The upper limit of the ionomer (C) in the ionomer resin layer is not particularly limited, but is, for example, 100% by mass or less.

[0062] From the viewpoint of improving the mechanical strength, the thickness of the ionomer resin layer is preferably 10 μm or more, more preferably 50 μm or more, even more preferably 100 μm or more, even more preferably 250 μm or more, even more preferably 500 μm or more, even more preferably 750 μm or more, and even more preferably 1000 μm or more, and from the viewpoint of improving the transparency of the obtained laminated glass or solar cell module, the thickness is preferably 5000 μm or less, more preferably 3000 μm or less, and even more preferably 2000 μm or less.

[0063] The ionomer (C) of ethylene-unsaturated carboxylic acid copolymer is an ionomer of a polymer obtained by copolymerizing ethylene with at least one unsaturated carboxylic acid, and is a resin in which at least a portion of the carboxyl groups of the ethylene-unsaturated carboxylic acid copolymer have been neutralized with metal ions. The ethylene-unsaturated carboxylic acid copolymer, which is the base resin of the ionomer (C) of the ethylene-unsaturated carboxylic acid copolymer, is a polymer obtained by copolymerizing at least ethylene and an unsaturated carboxylic acid as copolymerization components, and if necessary, a monomer other than ethylene and an unsaturated carboxylic acid may be copolymerized. The ethylene-unsaturated carboxylic acid copolymer may be used alone or in combination of two or more kinds.

[0064] The ethylene-unsaturated carboxylic acid copolymer may be in the form of a block copolymer, a random copolymer, or a graft copolymer. However, in consideration of productivity, it is preferable to use a binary random copolymer, a tertiary random copolymer, a graft copolymer of a binary random copolymer, or a graft copolymer of a tertiary random copolymer, and more preferably a binary random copolymer or a tertiary random copolymer.

[0065] Examples of the unsaturated carboxylic acid constituting the ethylene-unsaturated carboxylic acid copolymer include unsaturated carboxylic acids or half esters having 4 to 8 carbon atoms, such as acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, maleic acid, maleic anhydride, maleic acid monoesters (monomethyl maleate, monoethyl maleate, etc.), and maleic anhydride monoesters (monomethyl maleate, monoethyl maleate, etc.). Among these, the unsaturated carboxylic acid preferably includes at least one selected from acrylic acid and methacrylic acid, from the viewpoint of improving the productivity of the ethylene-unsaturated carboxylic acid copolymer. These unsaturated carboxylic acids may be used singly or in combination of two or more.

[0066] When all the structural units of the ethylene-unsaturated carboxylic acid copolymer are taken as 100% by mass, the content of structural units derived from ethylene in the ethylene-unsaturated carboxylic acid copolymer is, from the viewpoint of further improving heat resistance and processability, preferably 65% ​​by mass or more, more preferably 70% by mass or more, even more preferably 75% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less. When all the constituent units of the ethylene-unsaturated carboxylic acid copolymer are taken as 100% by mass, the content of constituent units derived from unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer is, from the viewpoint of further improving transparency and adhesiveness, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 18% by mass or more, even more preferably 19% by mass or more, and preferably 35% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, even more preferably 22% by mass or less, even more preferably 21% by mass or less. Here, the content of the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer can be measured, for example, by Fourier transform infrared absorption spectroscopy (FT-IR).

[0067] The ethylene-unsaturated carboxylic acid copolymer is a copolymer in which at least ethylene and an unsaturated carboxylic acid are copolymerized, and may also be a ternary or higher multi-component copolymer in which a third copolymer component is further copolymerized. Examples of the third copolymerization component include unsaturated carboxylic acid esters (e.g., (meth)acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, dimethyl maleate, and diethyl maleate), vinyl esters (e.g., vinyl acetate and vinyl propionate), unsaturated hydrocarbons (e.g., propylene, butene, 1,3-butadiene, pentene, 1,3-pentadiene, and 1-hexene), oxides such as vinyl sulfate and vinyl nitrate, halogen compounds (e.g., vinyl chloride and vinyl fluoride), vinyl group-containing primary and secondary amine compounds, carbon monoxide, and sulfur dioxide. Among these, as the third copolymerization component, unsaturated carboxylic acid esters are preferred, and (meth)acrylic acid alkyl esters (the alkyl moiety preferably has 1 or more and 4 or less carbon atoms) are more preferred.

[0068] The content ratio of the structural units derived from the third copolymerization component in the ethylene-(meth)acrylic acid copolymer is preferably in the range of 25% by mass or less from the viewpoint of production and mixing.

[0069] Examples of metal ions constituting the ionomer (C) of ethylene-unsaturated carboxylic acid copolymer include alkali metal ions such as lithium ion, potassium ion, and sodium ion, and polyvalent metal ions such as calcium ion, magnesium ion, zinc ion, aluminum ion, and barium ion. These metal ions may be used alone or in combination of two or more. Among these, it is preferable to contain at least one selected from sodium ions, zinc ions and magnesium ions, and it is more preferable to contain magnesium ions.

[0070] The degree of neutralization of the ionomer (C) of the ethylene-unsaturated carboxylic acid copolymer is, from the viewpoint of further improving transparency, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, even more preferably 30 mol% or more, and even more preferably 40 mol% or more, and, from the viewpoint of further improving adhesiveness, processability, and moldability, is preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 80 mol% or less, even more preferably 70 mol% or less, even more preferably 60 mol% or less, even more preferably 50 mol% or less, and even more preferably 45 mol% or less. Here, the degree of neutralization of the ionomer (C) of the ethylene-unsaturated carboxylic acid copolymer can be measured, for example, by incineration residue analysis.

[0071] The method for producing the ionomer (C) of the ethylene-unsaturated carboxylic acid copolymer is not particularly limited, and it can be produced by a known method. In addition, commercially available ionomers of the ethylene-unsaturated carboxylic acid copolymer (C) may be used.

[0072] The melt flow rate (MFR) of the ionomer (C) of ethylene-unsaturated carboxylic acid copolymer, measured in accordance with JIS K 7210:1999 under conditions of 190°C and a load of 2160 g, is preferably 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, even more preferably 1.0 g / 10 min or more, even more preferably 1.5 g / 10 min or more, and even more preferably 2.0 g / 10 min or more, from the viewpoint of further improving the interlayer adhesion and formability of the laminated glass interlayer film, and is preferably 30 g / 10 min or less, more preferably 15 g / 10 min or less, even more preferably 10 g / 10 min or less, even more preferably 5 g / 10 min or less, and even more preferably 3.0 g / 10 min or less.

[0073] The ionomer resin layer may contain components other than the ionomer (C) of the ethylene-unsaturated carboxylic acid copolymer, as long as the purpose of the present invention is not impaired. These other components are not particularly limited, but examples include plasticizers, antioxidants, UV absorbers, antistatic agents, surfactants, colorants, light stabilizers, foaming agents, lubricants, crystal nucleating agents, crystallization accelerators, crystallization retarders, catalyst deactivators, thermoplastic resins other than the ionomer (C), thermosetting resins, inorganic fillers, organic fillers, impact modifiers, slip agents, crosslinking agents, crosslinking aids, tackifiers, silane coupling agents, processing aids, mold release agents, hydrolysis inhibitors, heat stabilizers, antiblocking agents, antifogging agents, flame retardants, flame retardant aids, light diffusing agents, antibacterial agents, antifungal agents, dispersants, and other resins. These other components may be used alone or in combination. However, it is preferred that the ionomer resin layer does not contain an epoxy group-containing ethylene copolymer.

[0074] <Polyester resin layer> The polyester resin layer contains a polyester resin (D), preferably containing the polyester resin (D) as a main component. Here, "main component" means that the polyester resin (D) accounts for 50% by mass or more of the polyester resin layer. The content of the polyester resin (D) in the polyester resin layer is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, when the entire polyester resin layer is taken as 100% by mass. The upper limit of the polyester resin (D) in the polyester resin layer is not particularly limited, but is, for example, 100% by mass or less.

[0075] The thickness of the polyester resin layer is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, even more preferably 30 μm or more, even more preferably 50 μm or more, and even more preferably 75 μm or more, from the viewpoint of further improving the mechanical strength and designability, and is preferably 2000 μm or less, more preferably 1000 μm or less, even more preferably 500 μm or less, even more preferably 200 μm or less, and even more preferably 150 μm or less, from the viewpoint of improving the transparency and interlayer adhesion of the resulting laminated glass or solar cell module.

[0076] Examples of the polyester resin (D) include polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN). The surface of the polyester resin layer may be subjected to an adhesion-enhancing treatment such as coating. The polyester resin layer may also be a multilayer film made of the above-mentioned multiple types of polyester resin layers.

[0077] The polyester resin layer can be industrially produced as a monolayer film made of the above polyester by the known T-die cast film method, or as a co-extruded film using two or more polyesters or resins other than polyester by the co-extrusion T-die cast film method. These may be unstretched, but are preferably stretched films from the viewpoint of further improving the toughness, transparency, heat resistance, gas barrier properties, etc. of the film.

[0078] The overall thickness of the laminated glass interlayer film according to the present invention is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more, from the viewpoint of further improving the mechanical strength, and is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less, from the viewpoint of improving the transparency and interlayer adhesion of the resulting laminated glass.

[0079] The method for producing the laminated glass interlayer film according to the present invention is not particularly limited, and any conventionally known production method can be used. The laminated glass interlayer film according to the present invention can be produced by, for example, press molding, extrusion molding, T-die molding, injection molding, compression molding, cast molding, calendar molding, inflation molding, or the like.

[0080] 3. Laminated glass The laminated glass of the present invention comprises the laminated glass interlayer film of the present invention and transparent plate-like members provided on both sides of the laminated glass interlayer film. Here, in this specification, the "transparent plate-like members" are also referred to as "glass." The laminated glass according to the present invention has improved transparency and interlayer adhesion due to the inclusion of the laminated glass interlayer film according to the present invention. Two or more layers of the laminated glass interlayer may be used, or a layer made of another resin may be sandwiched between two laminated glass interlayers to form three or more layers.

[0081] Examples of the layer structure of the laminated glass according to the present invention include the structures of Examples 1 to 3 below. Example 1: Transparent plate-shaped member / ionomer resin layer / adhesive resin layer / transparent plate-shaped member Example 2: Transparent plate-shaped member / ionomer resin layer / adhesive resin layer / polyester resin layer / adhesive resin layer / transparent plate-shaped member Example 3: Transparent plate-shaped member / ionomer resin layer / adhesive resin layer / polyester resin layer / adhesive resin layer / ionomer resin layer / transparent plate-shaped member The layer structure of the laminated glass according to the present invention preferably includes at least one structure in which a transparent plate-like member and an ionomer resin layer are adjacent to each other. By providing an ionomer resin layer between the transparent plate-like member and the adhesive resin layer, the durability of the laminated glass can be further improved.

[0082] The transparent plate-like member is not particularly limited, and can be, for example, a commonly used transparent plate glass, such as float plate glass, polished plate glass, patterned plate glass, wired plate glass, striped plate glass, colored plate glass, heat-absorbing plate glass, heat-reflecting plate glass, or green glass. Organic plastic plates such as polycarbonate plate, poly(meth)acrylate plate, polymethyl(meth)acrylate plate, polystyrene plate, cyclic polyolefin plate, polyethylene terephthalate plate, polyethylene naphthalate plate, or polyethylene butyrate plate can also be used. Among these, transparent plate glass is preferred, and inorganic glass is more preferred. The transparent plate-like member may be subjected to a surface treatment such as corona treatment, plasma treatment, or flame treatment as appropriate.

[0083] The thickness of the transparent plate-like member is preferably 0.1 mm or more, more preferably 0.5 mm or more, even more preferably 1 mm or more, and is preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5 mm or less. In the laminated glass of the present invention, the transparent plate-like members provided on both sides of the laminated glass interlayer film may be the same, or different plate-like members may be used in combination.

[0084] The method for producing the laminated glass according to the present invention is not particularly limited, and can be a conventionally known production method such as a nip roll method, an autoclave method, a vacuum bag method, a vacuum laminator method, etc. The laminated glass according to the present invention can be produced by using one of these methods or by combining two or more of them. The laminated glass according to the present invention can be produced, for example, by sandwiching the laminated glass interlayer according to the present invention between two transparent plate-like members, followed by heating and pressurizing. Among these, a method that combines the nip roll method and the autoclave method, or a method that combines the vacuum bag method and the autoclave method, is preferred as a method for producing the laminated glass according to the present invention. In a method combining the nip roll method and the autoclave method, for example, a laminated glass is obtained by sandwiching the laminated glass interlayer film according to the present invention between two transparent plate-like members, pre-pressing the resulting laminate with nip rolls, and then subjecting the laminate to a heat and pressure treatment in an autoclave for thermocompression bonding. A method combining the vacuum bag method and the autoclave method is, for example, a method in which a laminated glass is obtained by sandwiching the laminated glass interlayer film according to the present invention between two transparent plate-like members, placing the laminated glass interlayer film between two transparent plate-like members in a vacuum bag, reducing the pressure inside the vacuum bag to temporarily press-bond the laminated glass, and then subjecting the laminated glass to a heat and pressure treatment in an autoclave to perform thermocompression bonding, thereby obtaining a laminated glass.

[0085] The laminated glass according to the present invention can be used for various purposes, including, but not limited to, laminated glass for architecture, laminated glass for automobiles, general buildings, agricultural buildings, and railway windows.

[0086] 4. Solar cell encapsulant The solar cell encapsulant according to the present invention includes an adhesive resin layer containing the adhesive resin composition according to the present invention. The layer structure and preferred embodiments of each layer of the solar cell encapsulant according to the present invention are the same as those of the laminated glass interlayer according to the present invention, and therefore, description thereof will be omitted here. The solar cell encapsulant according to the present invention can be produced by the same production method as the laminated glass interlayer according to the present invention.

[0087] 5. Solar cell modules The solar cell module according to the present invention includes a solar cell element and an encapsulating resin layer made of the solar cell encapsulant according to the present invention for encapsulating the solar cell element. By including the encapsulating resin layer made of the solar cell encapsulant according to the present invention, the solar cell module according to the present invention has improved transparency and interlayer adhesion. The solar cell module according to the present invention may further include, as necessary, a substrate onto which sunlight is incident, a protective material, etc. The substrate onto which sunlight is incident may also be simply referred to as the substrate. The solar cell module according to the present invention can be produced, for example, by sandwiching a solar cell element between solar cell encapsulant materials, which are then sandwiched between a substrate and a protective material to produce a laminate, and then heating and pressurizing the laminate to bond the components together.

[0088] Such solar cell modules can be exemplified by various types, including those configured such that substrate / sealant / solar cell element / sealant / protective material are laminated in this order and the solar cell element is sandwiched between the sealants on both sides; those configured such that solar cell elements pre-formed on the surface of a substrate such as glass are laminated in this order: substrate / solar cell element / sealant / protective material; and those configured such that a sealant and a protective material are formed on a solar cell element formed on the inner peripheral surface of a substrate, for example, an amorphous solar cell element fabricated by sputtering or the like on a fluororesin sheet. In addition, when the substrate onto which sunlight is incident is considered to be the upper part of the solar cell module, the protective material is provided on the opposite side of the solar cell module from the substrate side, i.e., on the lower part, so it is sometimes called a lower protective material or a back surface protective material.

[0089] As the solar cell element, various types of solar cell elements can be used, such as silicon-based elements such as single crystal silicon, polycrystalline silicon, and amorphous silicon; III-V group or II-VI group compound semiconductor-based elements such as gallium-arsenide, copper-indium-selenium, copper-indium-gallium-selenium, and cadmium-tellurium; and heterojunction types of amorphous silicon and single crystal silicon. In a solar cell module, a plurality of solar cell elements are electrically connected in series via, for example, an interconnector.

[0090] The solar cell module according to the present invention includes, for example, a metal material provided adjacent to the encapsulating resin layer. Such a metal material is, for example, a wiring, an electrode, or the like. Examples of the metal material include bus bar electrodes, interconnectors, finger electrodes, and the like. The bus bar electrodes, interconnectors, and finger electrodes are used in the module to join solar cell elements together and to collect generated electricity. The metal material includes, for example, at least one metal selected from copper, tin, lead, iron, bismuth, aluminum, and silver.

[0091] Examples of substrates constituting the solar cell module according to the present invention include glass substrates, acrylic resin substrates, polycarbonate substrates, polyester substrates, and fluorine-containing resin substrates. The protective material (lower protective material) is a single or multilayer sheet of metal, various inorganic materials, various thermoplastic resin films, etc., and examples thereof include single or multilayer sheets made of metals such as tin, aluminum, stainless steel, etc., inorganic materials such as glass, and thermoplastic resin films such as polyester, inorganic-deposited polyester, fluorine-containing resin, and polyolefin, etc. The solar cell encapsulant according to the present invention exhibits good adhesion to these substrates or protective materials.

[0092] The method for producing the solar cell module according to the present invention is not particularly limited, and can be any conventionally known production method such as a nip roll method, an autoclave method, a vacuum bag method, a vacuum laminator method, etc. One of these methods may be used for production, or two or more production methods may be combined. Among these, the method of manufacturing the solar cell module according to the present invention is preferably a manufacturing method using a vacuum laminator. The method using a vacuum laminator is, for example, a method in which a laminate obtained by sandwiching the solar cell encapsulant and solar cell element according to the present invention between a substrate and a protective material is heated and vacuum-deaerated in a double vacuum device, and then a diaphragm rubber is placed from the top of the double vacuum device in a pressure step to heat and pressurize the laminate to thermocompress it, thereby obtaining a solar cell module.

[0093] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0094] The present embodiment will be described in detail below with reference to examples, etc. However, the present embodiment is not limited to the descriptions of these examples.

[0095] [material] The components used were as follows. The melt flow rate (MFR) was measured at 190°C under a load of 2160g in accordance with JIS K 7210:1999. The Vicat softening point was measured in accordance with JIS K 7206:1999.

[0096] <Ethylene-unsaturated ester copolymer (A)> EVA1: Ethylene-vinyl acetate copolymer (ethylene-derived structural unit content: 67% by mass, vinyl acetate-derived structural unit content: 33% by mass, MFR (190°C, 2160g load): 14g / 10min) EVA2: Ethylene-vinyl acetate copolymer (ethylene-derived structural unit content 72% by mass, vinyl acetate-derived structural unit content 28% by mass, MFR (190°C, 2160g load) 15g / 10min) EVA3: Ethylene-vinyl acetate copolymer (ethylene-derived structural unit content: 81% by mass, vinyl acetate-derived structural unit content: 19% by mass, MFR (190°C, 2160g load): 15g / 10min) EVA4: Ethylene-vinyl acetate copolymer (ethylene-derived structural unit content: 81% by mass, vinyl acetate-derived structural unit content: 19% by mass, MFR (190°C, 2160g load): 150g / 10min) The content of structural units derived from vinyl acetate was measured in accordance with JIS K 7192: 1999. The content of structural units derived from ethylene was determined by subtracting the content of structural units derived from vinyl acetate from the total content of structural units derived from ethylene and vinyl acetate, which was set to 100% by mass.

[0097] <Epoxy group-containing ethylene copolymer (B)> EMAGMA1: Ethylene-methyl acrylate-glycidyl methacrylate copolymer (content of structural units derived from ethylene: 67% by mass, content of structural units derived from methyl acrylate: 27% by mass, content of structural units derived from glycidyl methacrylate: 6% by mass; manufactured by Sumitomo Chemical Co., Ltd., Bondfast 7M (trade name), MFR (190°C, 2160g load): 7g / 10min, melting point: 52°C, Vicat softening point: less than 25°C) EMAGMA2: Ethylene-methyl acrylate-glycidyl methacrylate copolymer (content of structural units derived from ethylene: 70% by mass, content of structural units derived from methyl acrylate: 27% by mass, content of structural units derived from glycidyl methacrylate: 3% by mass; manufactured by Sumitomo Chemical Co., Ltd., Bondfast 7L (trade name), MFR (190°C, 2160g load): 7g / 10min, melting point: 60°C, Vicat softening point: less than 25°C) EVAGMA1: ethylene-vinyl acetate-glycidyl methacrylate copolymer (content of structural units derived from ethylene: 83% by mass, content of structural units derived from vinyl acetate: 5% by mass, content of structural units derived from glycidyl methacrylate: 12% by mass, manufactured by Sumitomo Chemical Co., Ltd., Bondfast 7B (trade name), MFR (190°C, 2160g load): 7g / 10min, melting point: 95°C, Vicat softening point: 66°C) The melting point of the epoxy group-containing ethylene copolymer (B) was measured in accordance with JIS K 7121-1987.

[0098] <Silane coupling agent> Silane coupling agent 1: 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM503 (trade name))

[0099] <Organic peroxide> Organic peroxide 1: 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (Arkema Yoshitomi Co., Ltd., Luperox 101 (trade name))

[0100] <Ionomer (C)> Ionomer 1: Mg ionomer of ethylene-methacrylic acid copolymer (content of structural units derived from ethylene: 80% by mass, content of structural units derived from methacrylic acid: 20% by mass, degree of neutralization: 44%, MFR (190°C, 2160g load): 2.5g / 10min)

[0101] [Examples 1 to 2 and Comparative Examples 1 to 3] The components were mixed in advance in the proportions shown in Table 1, fed into a 30 mmφ single-screw extruder equipped with a pelletizer (manufactured by Thermoplastics Corporation, model number: 53-103), melt-kneaded under the following extrusion conditions or melt-kneading conditions, and granulated to obtain pellets of the adhesive resin composition. The extrusion conditions for the single-screw extruder were as follows: L / D:28 Barrel temperature (℃); C1 (80), C2 (115), C3 (135), C4 (135), C5 (135), D (130) Screw rotation speed: 45 rpm Output: 3.5 kg / h Screen mesh: 60 / 120 / 60

[0102] [Examples 3 to 4] The ingredients were premixed in the proportions shown in Table 1, fed into a 40 mmφ single-screw extruder (manufactured by Nakatani Machinery Co., Ltd., model number: VSK40) equipped with a pelletizer, melt-kneaded under the following extrusion and melt-kneading conditions, and granulated to obtain pellets of the adhesive resin composition. The amounts (parts by mass) of the silane coupling agent and organic peroxide in Example 4 are values ​​relative to 100 parts by mass of the total amount of the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B). The silane coupling agent and organic peroxide were impregnated into the ethylene-unsaturated ester copolymer (A) and the epoxy group-containing ethylene copolymer (B), and then melt-kneaded. The extrusion conditions for the single-screw extruder were as follows: Screw: Tip Dulmage screw L / D:28 Barrel temperature (℃); C1 (120), C2 (160), C3 (180), C4 (200), D (160) Screw rotation speed: 45 rpm Extrusion rate: 10 kg / h Screen mesh: 60 / 120 / 60

[0103] <Evaluation of Optical Properties of Adhesive Resin Composition> (1) Sheet preparation The obtained adhesive resin composition was pressed at 140°C and 9.8 MPa using a hydraulic hot press (manufactured by Toho Machinery Co., Ltd., model number: TBDM50-2), and then cooled at 20°C and 14.7 MPa to produce a pressed sheet with a thickness of 3 mm.

[0104] (2) Haze measurement The haze of the obtained pressed sheet was measured in accordance with JIS K 7136:2000 using a haze meter (manufactured by Suga Test Instruments Co., Ltd., product name: HZ-V3 type). The haze was evaluated according to the following criteria. The evaluation results are shown in Table 1. (Haze evaluation criteria) A (Excellent): Haze is 10% or less B (Good): Haze is over 10% and 20% or less C (poor): Haze exceeds 20%

[0105] (3) Measurement of total light transmittance The total light transmittance of the obtained press sheet was measured using a haze meter (manufactured by Suga Test Instruments Co., Ltd., product name: HZ-V3 type) in accordance with JIS K 7361-1:1997. The total light transmittance was evaluated according to the following criteria. The evaluation results are shown in Table 1. (Evaluation criteria for total light transmittance) In the evaluation of the 3 mm thick press sheet produced by the above method, A (Excellent): Total light transmittance is 90% or more B (Good): Total light transmittance is 70% or more but less than 90% C (poor): Total light transmittance is less than 70%

[0106] (3) Yellow Index (YI) Measurement The YI (transmittance method) of the obtained pressed sheet was measured using a color meter (CC-iS, manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K 7373:2006. The YI was evaluated according to the following criteria. The evaluation results are shown in Table 1. (YI evaluation criteria) A (Excellent): YI is 3 or less B (Good): YI is over 3 and 5 or less C (Poor): YI is greater than 5

[0107] [Table 1]

[0108] As is clear from Table 1, the press sheets produced using the adhesive resin compositions of Examples 1 to 4 were excellent in all of haze, total light transmittance, and YI, and thus had excellent transparency. In contrast, the press sheet produced using the adhesive resin composition of Comparative Example 1, in which the ethylene content difference was 16% by mass, was poor in all of haze, total light transmittance, and YI, and thus had poor transparency. The press sheet produced using the adhesive resin composition of Comparative Example 2, in which the ethylene content difference was 11% by mass, was poor in haze and YI, and thus had poor transparency. The press sheet produced using the adhesive resin composition of Comparative Example 3, in which the unsaturated ester content of the ethylene-unsaturated ester copolymer was less than 20% by mass, was poor in YI and thus had poor transparency. From the above, it was confirmed that the adhesive resin composition according to the present invention can improve transparency.

[0109] [Examples 5 to 6 and Comparative Examples 4 to 5] The adhesive resin composition obtained in Example 3 is referred to as adhesive resin composition 1. The adhesive resin composition obtained in Example 4 is referred to as adhesive resin composition 2.

[0110] 25% by mass of EVA3, 25% by mass of EVA4, 50% by mass of EVAGMA1, 1.5 parts by mass of a silane coupling agent, and 0.3 parts by mass of an organic peroxide were premixed and fed into a 40 mmφ single-screw extruder (manufactured by Nakatani Machinery Co., Ltd.) equipped with a pelletizer. The mixture was melt-kneaded and granulated under the following extrusion and melt-kneading conditions to obtain pellets of an adhesive resin composition. The amounts (parts by mass) of the silane coupling agent and organic peroxide are based on 100 parts by mass of the combined ethylene-unsaturated ester copolymer (A) and epoxy group-containing ethylene copolymer (B). The extrusion conditions for the single-screw extruder were as follows. The resulting adhesive resin composition was designated Adhesive Resin Composition 3. Screw: Tip Dulmage screw L / D:28 Barrel temperature (℃); C1 (120), C2 (160), C3 (180), C4 (200), D (160) Screw rotation speed: 45 rpm Extrusion rate: 10 kg / h Screen mesh: 60 / 120 / 60

[0111] The adhesive resin composition was mixed in advance in the proportions shown in Table 2, fed into a 40 mm diameter T-die sheet molding machine (manufactured by Nakatani Machinery Co., Ltd., model number: VSK40), melt-kneaded under the following extrusion conditions or melt-kneading conditions, and extrusion sheet molding was carried out to prepare sheets of the adhesive resin composition having thicknesses of 100 μm and 300 μm. The extrusion conditions for the T-die sheet molding machine were as follows: Screw: Double flight with Dulmage tip L / D:26 Barrel temperature (℃); C1 (80), C2 (100), C3 (120), A (120), D1 (120), D2 (120), D3 (120) Screw rotation speed: 45 rpm Screen mesh: 60

[0112] <Evaluation of Optical Properties of Glass Laminate> (1) Preparation of glass laminate Using a vacuum heating laminator (double vacuum chamber laminator, manufactured by NPC Corporation, product name: LM-50×50S), glass, ionomer 1, a 100 μm-thick sheet made of the adhesive resin composition, and glass were laminated in this order and bonded at a heating temperature of 140° C., a heating pressure of 1 atm, and a heating time of 20 minutes. The laminate was then wrapped in bleached cloth, left to stand in the air, and slowly cooled by natural cooling to produce a glass laminate for evaluating optical properties. Configuration of glass laminate: Glass (3.2 mm thick) / Ionomer 1 (1500 μm thick) / Sheet made of adhesive resin composition (100 μm thick) / Glass (3.2 mm thick)

[0113] (2) Haze measurement The haze of the obtained glass laminate was measured in accordance with JIS K 7136:2000 using a haze meter (manufactured by Suga Test Instruments Co., Ltd., product name: HZ-V3 type). The haze was evaluated according to the following criteria. The evaluation results are shown in Table 2. (Haze evaluation criteria) A (Excellent): Haze is 5% or less B (Good): Haze exceeds 5% and is 10% or less. C (Poor): Haze exceeds 10%.

[0114] (3) Measurement of total light transmittance Using the obtained glass laminate, the total light transmittance was measured with a haze meter (manufactured by Suga Test Instruments Co., Ltd., product name: HZ-V3 type) in accordance with JIS K 7361-1:1997. The total light transmittance was evaluated according to the following criteria respectively. The evaluation results are shown in Table 2. [[ID=1,0]] [[ID=1,1]](Evaluation criteria for total light transmittance) [[ID=1,2]] [[ID=1,3]]A (Excellent): Total light transmittance is 85% or more. [[ID=1,4]] [[ID=1,5]]B (Good): Total light transmittance is 80% or more and less than 85%. [[ID=1,6]] [[ID=1,7]]C (Poor): Total light transmittance is less than 80%. [[ID=1,8]] [[ID=1,9]]

[0115] [[ID=2,0]] [[ID=2,1]](4) Measurement of yellow index (YI) [[ID=2,2]] [[ID=2,3]]Using the obtained glass laminate, in accordance with JIS K 7373:2006, YI (transmission method) was measured using a colorimeter (manufactured by Suga Test Instruments Co., Ltd., CC-iS). YI was evaluated according to the following criteria. The evaluation results are shown in Table 2. [[ID=2,4]] [[ID=2,5]](Evaluation criteria for YI) [[ID=2,6]] [[ID=2,7]]A (Excellent): YI is 3 or less. [[ID=2,8]] [[ID=2,9]]B (Good): YI exceeds 3 and is 5 or less. [[ID=3,0]] [[ID=3,1]]C (Poor): YI exceeds 5. [[ID=3,2]] [[ID=3,3]]

[0116] [[ID=3,4]] [[ID=3,5]](Adhesion evaluation to PET film) [[ID=3,6]] [[ID=3,7]]Using a vacuum heating laminator (double vacuum chamber laminator, manufactured by NPC Co., Ltd., product name: LM-50×50S), glass (non-tin surface as the bonding surface), a sheet made of the above-mentioned adhesive resin composition with a thickness of 300 μm, and a PET film with a thickness of 100 μm (untreated by corona) were laminated in this order, and laminated at a heating temperature of 140 °C, a pressure during heating of 1 atm, and a heating time of 60 minutes to produce a glass laminate. Then, the laminate was left to stand in the atmosphere and gradually cooled by natural cooling. [[ID=3,8]] [[ID=3,9]]Composition of the glass laminate: Glass (3.9 mm thick) / Sheet made of adhesive resin composition (300 μm thick) / PET film (100 μm thick) [[ID=4,0]] The resulting glass laminate was slit into a 15 mm wide sheet to form a test piece, which was then placed in a tensile tester. The PET film was peeled off at a tensile speed of 100 mm / min and a peel angle of 180°, and the average stress was determined as the initial adhesive strength (N / 15 mm).

[0117] The glass laminate was stored under conditions of 85°C and 90% relative humidity, and the adhesive strength of the glass laminate after 500 hours of storage and after 1000 hours of storage were measured. The adhesive strengths obtained were defined as the adhesive strength of each glass laminate to the PET film. The adhesiveness to the PET film was evaluated according to the following criteria. The measurement results are shown in Table 2. (Evaluation criteria for adhesion to PET film) A (Excellent): Adhesion strength to PET film is 15N / 15mm or more initially, after 500 hours, and after 1000 hours. B (Poor): Adhesion strength to PET film is less than 15N / 15mm at the initial stage, after 500 hours, or after 1000 hours.

[0118] <Evaluation of adhesion to glass> Using a vacuum heating lamination machine (double vacuum chamber lamination machine, manufactured by NPC Corporation, product name: LM-50x50S), glass (with the non-tin side as the bonding surface) and a 300 μm thick sheet made of the adhesive resin composition were laminated in this order, and then bonded at a heating temperature of 140°C, a heating pressure of 1 atm, and a heating time of 60 minutes to produce a glass laminate. Thereafter, the glass laminate was left to stand in the air and slowly cooled by natural cooling. Structure of glass laminate: Glass (3.9 mm thick) / Sheet made of adhesive resin composition (300 μm thick) A 15 mm wide slit was made in the sheet portion of the obtained glass laminate to prepare a test specimen, which was then placed in a tensile tester. The glass (3.9 mm thick) was peeled off from the sheet (300 μm thick) made of the adhesive resin composition at a pulling rate of 100 mm / min and a peel angle of 180°, and the average stress was determined as the initial adhesive strength (N / 15 mm).

[0119] The glass laminate was stored under conditions of 85°C and 90% relative humidity, and the adhesive strength of the glass laminate after 500 hours of storage and after 1000 hours of storage were measured. The adhesive strengths obtained were defined as the adhesive strength of each glass laminate to glass. The adhesiveness to glass was evaluated according to the following criteria. The measurement results are shown in Table 2. (Evaluation criteria for adhesion to glass) A (Excellent): Adhesion strength to glass is 20N / 15mm or more initially, after 500 hours, and after 1000 hours. B (Poor): Adhesion strength to glass is less than 20N / 15mm at least at the initial stage, after 500 hours, or after 1000 hours.

[0120] [Table 2]

[0121] As is clear from Table 2, the laminated glass laminates produced using the adhesive resin compositions of Examples 5 and 6 were excellent in all of haze, total light transmittance, and YI, and thus had excellent transparency. Furthermore, they also had excellent adhesion to PET film and adhesion to glass. In contrast, the glass laminate produced using the adhesive resin composition of Comparative Example 4, in which the ethylene content difference was 15.3% by mass, had poor haze and poor transparency. The glass laminate produced using the adhesive resin composition of Comparative Example 5, which did not contain the epoxy group-containing ethylene copolymer (B), had poor adhesion to PET film and adhesion to glass, and thus had poor adhesion. From the above, it was confirmed that the adhesive resin composition according to the present invention had improved transparency and adhesion to a polyester resin layer. Such glass laminates can be used, for example, in laminated glass or solar cell modules.

[0122] This application claims priority based on Japanese Patent Application No. 2022-040794, filed on March 15, 2022, the disclosure of which is incorporated herein in its entirety.

Claims

[Claim 1] An ethylene-unsaturated ester copolymer (A) and an epoxy group-containing ethylene copolymer (B) (excluding the ethylene-unsaturated ester copolymer (A)), the content of structural units derived from unsaturated esters in the ethylene-unsaturated ester copolymer (A) is more than 20 mass% based on all structural units constituting the ethylene-unsaturated ester copolymer (A), The content of structural units derived from ethylene relative to all structural units constituting the ethylene-unsaturated ester copolymer (A) (X １ ) and the content of structural units derived from ethylene relative to all structural units constituting the epoxy group-containing ethylene copolymer (B) (X ２ ) and the difference (X １ -X ２ ) has an absolute value of 10 mass % or less.