JP2012140581A - Two-component polyurethane-based adhesive, laminate using the same, and back sheet for solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-component polyurethane-based adhesive excellent in adhesivity and durability; and to provide a laminate and a back sheet for a solar cell.SOLUTION: This two-component polyurethane-based adhesive includes a liquid (A) comprising an isocyanate compound, preferably a three or more functional isocyanate compound, and a liquid (B) comprising a saponified ethylene-vinyl acetate copolymer, preferably a saponified ethylene-vinyl acetate copolymer containing 0.01-10 mol% of a vinyl alcohol residual group unit.

Description

  The present invention relates to a two-component polyurethane adhesive having excellent adhesion and durability, a laminate using the same, and a solar cell backsheet.

  Two-component polyurethane adhesives are widely used because various materials can be easily bonded. In general, a two-component polyurethane adhesive is composed of two types of liquids: a curing agent liquid containing an isocyanate compound and a main liquid containing a polyol component. The main liquid is a polyol such as polyester polyol or polyether polyol and an organic solvent. As a main component, the performance of the two-component polyurethane adhesive largely depends on the polyol component.

  A two-component polyurethane-based adhesive using a polyether-based polyol such as polypropylene glycol as a polyol component has a problem that it is thermally deteriorated at a high temperature exceeding 120 ° C. although it is excellent in moisture and heat resistance. In addition, the two-component polyurethane-based adhesive using a polyester-based polyol such as polyester as a polyol component is excellent in heat resistance but is inferior in heat-and-moisture resistance, so that it deteriorates when left under high temperature and high humidity. have. In order to solve these problems, a two-component polyurethane-based adhesive using hydrogenated polybutadiene polyol or the like (see, for example, Patent Document 1) has been proposed.

Japanese Patent Laying-Open No. 2002-26346 (refer to the claims)

  However, although the two-component polyurethane adhesive proposed in Patent Document 1 has a certain effect in improving durability, there is a problem that the miscibility with an isocyanate compound is poor.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a two-component polyurethane adhesive using a liquid consisting of a saponified ethylene-vinyl acetate copolymer has improved mixing properties and durability with an isocyanate compound. The inventors have found that the present invention is superior and have completed the present invention.

  That is, this invention uses the liquid (A) which consists of an isocyanate compound, and the liquid (B) which consists of the liquid (B) which consists of a saponified ethylene-vinyl acetate copolymer, and used it. The present invention relates to a laminate and a solar cell backsheet.

  Hereinafter, the present invention will be described in detail.

  The two-component polyurethane adhesive of the present invention is composed of two liquids: a liquid (A) composed of an isocyanate compound and a liquid (B) composed of a saponified ethylene-vinyl acetate copolymer.

  As the liquid (A), any liquid material composed of an isocyanate compound can be used. For example, a solution composed of an isocyanate compound and an organic solvent, an aqueous solution composed of an isocyanate compound and water, a suspension, a liquid An isocyanate compound etc. can be mentioned, Among these, since it becomes a two-component polyurethane adhesive excellent in applicability | paintability, it is preferable that it is a solution which consists of an isocyanate compound and an organic solvent.

  Examples of the isocyanate compound constituting the liquid (A) include diphenylmethane-4,4′-diisocyanate, toluene diisocyanate, phenylene diisocyanate, xylene diisocyanate, xylylene diisocyanate, tetramethylxylene diisocyanate, naphthalene diisocyanate, and triphenylmethane tris. Aromatic isocyanate compounds such as isocyanate and tris (isocyanatephenyl) thiophosphate; aliphatic isocyanate compounds such as hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate; Isophorone diisocyanate, dimer acid diisocyanate, dicyclohexylmethane diisocyanate, Chill cyclohexane diisocyanate, alicyclic isocyanate compounds such as norbornene diisocyanate, etc., and these may be used alone or may be used two or more kinds. Moreover, polyfunctional isocyanates, such as a burette modified body, allophanate modified body, adduct body, isosinurate modified body, polyphenylmethane polyisocyanate, etc. of these isocyanate compounds may be used. Among them, an aromatic isocyanate compound is preferable because it is a two-component polyurethane adhesive having particularly excellent durability, and diphenylmethane-4,4′-diisocyanate, toluene diisocyanate, and adducts of these isocyanate compounds are particularly preferable. An adduct of diphenylmethane-4,4′-diisocyanate and / or toluene diisocyanate is preferred.

  Further, the liquid (A) preferably contains a trifunctional or higher functional isocyanate compound because it becomes a two-component polyurethane adhesive having excellent adhesive strength.

  Examples of the organic solvent in the case where the liquid (A) is an isocyanate compound solution include organic solvents such as toluene, xylene, ethyl acetate, methyl ethyl ketone, methylene chloride, and tetrahydrofuran, and these may be used alone. It may be two or more. Among these, toluene, ethyl acetate, methyl ethyl ketone, and methylene chloride are preferable because of being a two-component polyurethane adhesive having excellent coating properties, and toluene, ethyl acetate, and methyl ethyl ketone are particularly preferable.

  The production of the liquid (A) is not particularly limited and a known method can be used. Examples thereof include a method of mixing an isocyanate compound and an organic solvent at room temperature, a method of heating and mixing, and a method of mixing at room temperature is preferable. Used.

  As the liquid (B), any liquid can be used as long as it is a liquid composed of a saponified ethylene-vinyl acetate copolymer. For example, a solution composed of a saponified ethylene-vinyl acetate copolymer and an organic solvent, saponified ethylene -A suspension composed of a vinyl acetate copolymer and water, a liquid saponified ethylene-vinyl acetate copolymer, etc. Among them, a saponified ethylene because it becomes a two-part polyurethane adhesive having excellent coating properties. -A solution comprising a vinyl acetate copolymer and an organic solvent is preferred.

  Examples of the saponified ethylene-vinyl acetate copolymer constituting the liquid (B) include copolymers comprising ethylene residue units and vinyl alcohol residue units, ethylene residue units, vinyl alcohol residue units, and vinyl acetate. Copolymers composed of residue units can be mentioned, and these copolymers can be used without limitation, and among them, a two-component polyurethane adhesive having particularly excellent adhesive strength can be used. A saponified ethylene-vinyl acetate copolymer having an alcohol residue unit of 0.01 to 10 mol%, particularly 0.1 to 5.0 mol% is preferred. Similarly, it is preferably a saponified ethylene-vinyl acetate copolymer having a vinyl acetate residue unit of 15 to 80% by weight, since it becomes a two-component polyurethane adhesive having particularly excellent adhesive strength. A saponified ethylene-vinyl acetate copolymer having a vinyl acetate residue unit of 20 to 50% by weight, more preferably 20 to 45% by weight, is preferable because it is a two-component polyurethane adhesive having excellent coating properties. Further, the saponified ethylene-vinyl acetate copolymer preferably has a melt flow rate (also referred to as MFR) of 1 to 20000 g / 10 minutes, and more preferably 10 to 1000 g / 10 minutes. preferable.

  The saponified ethylene-vinyl acetate copolymer is obtained by hydrolyzing a vinyl acetate residue unit in an ethylene-vinyl acetate copolymer produced by, for example, a high pressure polymerization method, an emulsion polymerization method, or a solution polymerization method. It can be obtained by saponification into residue units. In this case, for example, as a method of hydrolyzing an ethylene-vinyl acetate copolymer produced by a high pressure method, a method of performing a hydrolysis reaction using an alkali or an acid as a catalyst can be mentioned. Homogeneous saponification method in which ethylene-vinyl acetate copolymer is dissolved in a homogeneous system and the reaction is carried out in a homogeneous system. Law. Such saponified ethylene-vinyl acetate copolymers are, for example, (trade name) Mersen H 6410M (manufactured by Tosoh Corporation), (trade name) Mersen H 6210M (manufactured by Tosoh Corporation), (trade name) Mersen. H 6960 (manufactured by Tosoh Corporation), (trade name) Mersen H 3051R (manufactured by Tosoh Corporation) and the like can be obtained as commercial products.

  Examples of the organic solvent that may constitute the liquid (B) comprising a saponified ethylene-vinyl acetate copolymer in the present invention include organic solvents such as toluene, xylene, ethyl acetate, methyl ethyl ketone, methylene chloride, and tetrahydrofuran. These may be used alone or in combination of two or more. In particular, toluene, ethyl acetate, methyl ethyl ketone, and methylene chloride are preferable, and toluene, ethyl acetate, and methyl ethyl ketone are particularly preferable because of being a two-component polyurethane adhesive having excellent coating properties.

  There are no particular restrictions on the production of the liquid (B) comprising the saponified ethylene-vinyl acetate copolymer used in the present invention, and any known method can be used. For example, saponified ethylene-vinyl acetate copolymer, organic Examples thereof include a method of mixing the solvent at room temperature, a method of heating and mixing, and the method of heating and mixing is preferably used because dissolution is quick. The temperature at the time of heating and mixing is preferably 30 to 150 ° C, particularly preferably 50 to 110 ° C.

  The two-component polyurethane adhesive of the present invention acts as an adhesive by mixing and mixing the liquid (A) comprising the isocyanate compound and the liquid (B) comprising the saponified ethylene-vinyl acetate copolymer. In this case, the blending ratio is not particularly limited as long as it can act as an adhesive, and is particularly excellent in adhesiveness. Therefore, the isocyanate of the isocyanate compound contained in the liquid (A) comprising the isocyanate compound The molar ratio of the saponified ethylene-vinyl acetate copolymer contained in the saponified ethylene-vinyl acetate copolymer liquid (B) (mole number of isocyanate group / mole number of hydroxyl group, hereinafter R Is preferably 0.5 to 10, and more preferably 1 to 5. When the liquid is used as a reference, the liquid (A) made of an isocyanate compound is preferably 0.01 to 150 weight parts per 100 parts by weight of the liquid (B) made of an ethylene-vinyl acetate copolymer. More preferably, it is 1 to 100 parts by weight, and particularly preferably 0.1 to 60 parts by weight. And when mixing and mixing these, there is no restriction | limiting in particular and a well-known method can be used, for example, the liquid (A) which consists of an isocyanate compound, and the liquid (B) which consists of a saponified ethylene-vinyl acetate copolymer are made into room temperature. A method of mixing, a method of mixing by heating, and the like can be mentioned, and a method of mixing at room temperature is preferably used.

  In addition, when the two-component polyurethane adhesive of the present invention is mixed and blended and acts as an adhesive, it is preferable to use a urethanization reaction catalyst in order to increase its quick drying property, There are no particular limitations, and known ones can be used. Examples include amine catalysts such as triethylamine, triethylenediamine, N-methylmorpholine, and tin catalysts such as tetramethyltin, tetraoctyltin, dimethyldioctyltin, triethyltin chloride, dibutyltin diacetate, and dibutyltin dilaurate. , One or more of these can be used. Among them, dibutyltin dilaurate is preferably used because of its high catalytic activity. Moreover, when using this urethanization reaction catalyst, what is necessary is just to add, when mixing and mix | blending the liquid (A) which consists of an isocyanate compound, and the liquid (B) which consists of a saponified ethylene-vinyl acetate copolymer. And since simple handling becomes possible, this urethanation reaction catalyst is mix | blended with the liquid (A) which consists of an isocyanate compound, and / or the liquid (B) which consists of a saponified ethylene-vinyl acetate copolymer. It is preferable to keep it.

  Moreover, as a compounding quantity of the urethanization reaction catalyst that is preferably added, since the quick-drying property of the two-component polyurethane adhesive obtained is improved, the amount of the urethanization reaction catalyst is preferably set to 0.1% with respect to 100 parts by weight of the two-component polyurethane adhesive. It is preferable to add 0001 to 1 part by weight, more preferably 0.001 to 0.5 part by weight, and particularly preferably 0.001 to 0.1 part by weight.

  Furthermore, the two-component polyurethane adhesive of the present invention preferably contains an antioxidant because it can suppress coloring, and the antioxidant is not limited at all. For example, a phenolic antioxidant, a phosphorous oxidation Antioxidants, sulfur-based antioxidants, amine-based antioxidants, lactone-based antioxidants, vitamin E-based antioxidants, and the like. These antioxidants can be used in combination of two or more in order to exhibit a greater effect. Moreover, as a compounding quantity of the antioxidant which it is preferable to add, since coloring of the two-component polyurethane adhesive obtained can be suppressed, 0.001-1 based on 100 parts by weight of the two-component polyurethane adhesive. 0.0 part by weight is preferably added, more preferably 0.001 to 0.5 part by weight, and particularly preferably 0.001 to 0.1 part by weight.

  Among these antioxidants, since the effect of suppressing coloring is large, 2,6-di-t-butyl-4-methylphenol and pentaerythritol tetrakis (3- (3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate).

  Moreover, it is preferable to mix | blend antioxidant also in the liquid (A) which consists of an isocyanate compound and / or the liquid (B) which consists of a saponified ethylene-vinyl acetate copolymer similarly to this urethanation reaction catalyst.

  The two-component polyurethane adhesive of the present invention may contain various additives as long as the effects of the present invention are not impaired. Examples of the various additives include dyes, organic pigments, inorganic pigments, inorganic reinforcing agents, plasticizers, processing aids such as acrylic processing aids, ultraviolet absorbers, light stabilizers, lubricants, waxes, crystal nucleating agents, plasticizers. Agent, mold release agent, hydrolysis inhibitor, antiblocking agent, antistatic agent, antifogging agent, antifungal agent, rust preventive agent, ion trap agent, flame retardant, flame retardant aid, inorganic filler, organic filler Etc.

  The two-component polyurethane adhesive of the present invention is useful for adhesion of various films, sheets, molded articles, foams, laminate adhesion, etc., and particularly exhibits excellent adhesion as an adhesive for polyester films. It is.

  The two-component polyurethane adhesive of the present invention is, for example, a resin film, foam, cloth, non-woven fabric, synthetic fiber, synthetic leather, leather, metal, metal oxide, rubber, thermoplastic elastomer, thermoplastic resin, thermosetting. It is possible to construct a laminate by pasting together a base material layer selected from the group consisting of resin, paper, wood, glass, stone, ceramics, porcelain, and in particular, a laminate with a wide range of use can be obtained. A laminate with a resin film is preferred.

  Examples of the resin film include polytetrafluoroethylene, 4-fluoroethylene-perchloroalkoxy copolymer, 4-fluorinated ethylene-6-fluoropropylene copolymer, 2-ethylene-4-fluoroethylene copolymer. Fluorine resin films such as polymers, polyvinylidene fluoride, and polyvinyl fluoride; polyester films such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate films, polyamide films, polymethyl methacrylate films, polyvinyl alcohol films, saponified polyethylene resin films, Examples thereof include a resin film such as an ethylene-vinyl acetate copolymer resin film. Among them, a polyester film and a fluororesin film are preferable because of excellent heat resistance and durability, and a polyethylene terephthalate film, a polyethylene naphthalate film, and a polyvinyl fluoride resin film are particularly preferable.

  Further, the resin film may be subjected to silicon treatment, hard coating treatment such as acrylic resin on the surface, or metal and / or metal oxide vapor deposition treatment such as aluminum, aluminum oxide and / or silicon oxide. Examples of the metal include metal foils such as aluminum, copper, and stainless steel, various films such as metal films and metal sheets, those obtained by polymer coating on these metal materials, and those subjected to inorganic coating as necessary. be able to.

  Examples of the foam include a polyethylene foam, a polypropylene foam, a polystyrene foam, a phenol resin foam, and a polyurethane foam.

  In producing a laminate using the two-component polyurethane adhesive of the present invention, for example, a multilayer dry laminate molding method can be mentioned. Since the adhesive strength of each layer of the laminate can be increased, it is preferably aged at 40 to 100 ° C. after being laminated by a dry laminating method to form a laminate.

  In addition, the two-component polyurethane adhesive of the present invention includes, for example, a polyester film; a polyester film deposited with an inorganic material such as aluminum, aluminum oxide, and silicon oxide; a fluorine resin film; Is possible. Among them, a back sheet for a solar cell including a laminate in which a polyester film and a polyester film on which an inorganic material such as aluminum, aluminum oxide, or silicon oxide is deposited is bonded with the two-component polyurethane adhesive of the present invention is preferable.

  The two-component polyurethane adhesive of the present invention is excellent in adhesion and durability, and is useful in various fields.

  The present invention will be described in more detail based on the following examples. However, these are examples to help understanding of the present invention, and the present invention is not limited to these examples. Commercially available products were used unless otherwise specified.

(Reagents, etc.)
Reagents and the like used in Examples and Comparative Examples are represented using the following abbreviations.

<Saponified ethylene-vinyl acetate copolymer>
EVAOH-1; Mersen (registered trademark) H6410 (vinyl acetate residue unit content 18% by weight, vinyl alcohol residue unit 4.4 mol%, MFR = 16 g / 10 min), manufactured by Tosoh Corporation.

<Ethylene-vinyl acetate copolymer>
EVA-1; Ultrasen (registered trademark) 760 (vinyl acetate residue unit content 42 wt%, MFR = 70 g / 10 min), manufactured by Tosoh Corporation.
EVA-2; Ultrasen (registered trademark) 720 (vinyl acetate residue unit content 28 wt%, MFR = 400 g / 10 min), manufactured by Tosoh Corporation.
EVA-3; Ultrasen (registered trademark) 751 (vinyl acetate residue unit content 28 wt%, MFR = 5.7 g / 10 min, density = 952 kg / m ³ ), manufactured by Tosoh Corporation.

<Liquid made of isocyanate compound>
Isocyanate compound solution (A1); (trade name) Coronate HX (isocinurate-modified product of hexamethylene diisocyanate), manufactured by Nippon Polyurethane Industry Co., Ltd.
Isocyanate compound solution (A2); (trade name) Coronate L (ethyl acetate solution of adduct composed of toluene diisocyanate and trimethylolpropane, isocyanate content 13.4% by weight), manufactured by Nippon Polyurethane Industry Co., Ltd.

<Antioxidant>
AO-60 (pentaerythritol tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate)); ADK STAB (registered trademark) AO-60, manufactured by Asahi Denka Kogyo Co., Ltd.

<Base material>
PET-1: Polyethylene terephthalate film, Melinex (registered trademark) type S (thickness: 100 μm), manufactured by Teijin DuPont Films Ltd.
AL-1; Aluminum foil A-1N30H18 (thickness: 100 μm), manufactured by Toyo Aluminum Co., Ltd.
ALPET-1; aluminum vapor-deposited polyethylene terephthalate film, Attack VM-PET MSAA (thickness: 12 μm), manufactured by Meiwa Packs Co., Ltd.

<Sealing film>
100 parts by weight of EVA-3 as an ethylene-vinyl acetate copolymer, 2 parts by weight of 1,1-di (tert-hexylperoxy) -3,3,5-trimethylcyclohexane as a crosslinking agent, and trimethyl as a crosslinking aid 2 parts by weight of allyl isocyanurate and 0.5 parts by weight of γ-methacrylopropyltrimethoxysilane as a silane coupling agent were blended and melt kneaded in a 20 mmφ single screw extruder set at a temperature of 110 ° C. to obtain pellets. It was.

  The obtained pellets were compression molded to produce a sealing film having a thickness of 0.5 mm. The compression molding was performed by heating at 110 ° C. for 300 seconds and then cooling at 30 ° C. for 300 seconds.

(Physical property test method)
<Adhesive strength>
The laminate was cut to a width of 25 mm, and the T-type peel strength was measured using a tensile tester ((trade name) Tensilon RTE-1210, manufactured by Orientec) to obtain the adhesive strength.

<Moist heat test>
Using a high-temperature and high-humidity device ((trade name) ETAC HI FX FX4200, manufactured by Enomoto Kasei Co., Ltd.), the test piece was left for 500 hours under the conditions of a temperature of 85 ° C. and a relative humidity of 85% RH.

Example 1
In a 0.5 liter separable flask, 113 g of toluene and 20 g of EVAOH-1 were added, heated to 110 ° C. with stirring and dissolved over 1 hour, and saponified ethylene-vinyl acetate copolymer solution (B1 )

  Then, 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) heated to 90 ° C. and 54 parts by weight of the isocyanate compound solution (A1) were mixed to prepare a two-part polyurethane adhesive. Prepared. The R of the two-component polyurethane adhesive was 2.0.

  Using a spin coater ((trade name) 1H-DX, manufactured by Mikasa Co., Ltd.), the obtained two-component polyurethane adhesive was applied to the base material PET-1, and a dryer ((trade name) SPH. -101, manufactured by ESPEC Corporation) was dried at 100 ° C. for 1 minute, and then a PET-1 as another substrate and a laminated laminate were obtained.

  The obtained laminate was aged at 100 ° C. for 24 hours, and then the initial adhesive strength was measured. The results are shown in Table 1. The obtained laminate showed excellent adhesive strength. The obtained laminate was subjected to a wet heat test, and the adhesive strength after the wet heat test was measured.

  The adhesive strength after the wet heat test showed 80% or more of the initial adhesive strength, and the obtained laminate showed excellent wet heat resistance.

Example 2
Instead of 100 parts by weight of saponified ethylene-vinyl acetate copolymer solution (B1) and 54 parts by weight of isocyanate compound solution (A1), 100 parts by weight of saponified ethylene-vinyl acetate copolymer solution (B1), A two-component polyurethane adhesive was prepared in the same manner as in Example 1 except that the isocyanate compound solution (A1) was 134 parts by weight. At that time, 0.1 part by weight of AO-60 with respect to 100 parts by weight of the two-component polyurethane adhesive was previously blended in the saponified ethylene-vinyl acetate copolymer solution (B1).

  And it evaluated by the method similar to Example 1 except having used base material AL-1 as a laminated body instead of base material PET-1. The evaluation results are shown in Table 1.

Example 3
1000 ml of methanol, 300 g of EVA-1 and 13.4 g of sodium methoxide were placed in a 2 liter autoclave equipped with stirring blades, heated to 50 ° C., and subjected to saponification reaction for 0.5 hours. After the reaction, the content was filtered, washed with methanol, neutralized, washed with water, and vacuum dried to obtain a saponified ethylene-vinyl acetate copolymer (hereinafter referred to as EVAOH-2). EVAOH-2 had a vinyl acetate residue unit content of 38% by weight, a vinyl alcohol residue unit of 2.2 mol%, and an MFR = 71 g / 10 min.

  In a 0.5 liter separable flask, 113 g of toluene, 20 g of the obtained EVAOH-2, 0.095 g of dibutyltin dilaurate as a urethanization reaction catalyst were placed, heated to 110 ° C. with stirring, and over 1 hour. To obtain a saponified ethylene-vinyl acetate copolymer solution (B2).

  Then, 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) and 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B2) instead of 54 parts by weight of the isocyanate compound solution (A1). A two-component polyurethane adhesive was prepared in the same manner as in Example 1 except that 27 parts by weight of the isocyanate compound solution (A2) was used.

  Moreover, it evaluated by the method similar to Example 1 except having used base material PET-1 and ALPET-1 instead of base material PET-1, and having set it as the laminated body. The evaluation results are shown in Table 1.

Example 4
In a 2 liter autoclave with a stirring blade, 1000 ml of methanol, 300 g of EVA-1 and 13.4 g of sodium methoxide were placed, heated to 40 ° C., and subjected to a saponification reaction for 0.3 hours. After the reaction, the content was filtered, washed with methanol, neutralized, washed with water, and vacuum dried to obtain a saponified ethylene-vinyl acetate copolymer (hereinafter referred to as EVAOH-3). The obtained EVAOH-3 had a vinyl acetate residue unit content of 41.5% by weight, a vinyl alcohol residue unit of 0.25 mol%, and MFR = 71 g / 10 min.

  A 0.5 liter separable flask was charged with 113 g of toluene and 20 g of the resulting EVAOH-3, heated to 110 ° C. with stirring and dissolved over 1 hour, and saponified ethylene-vinyl acetate copolymer. A solution (B3) was obtained.

  Then, instead of 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) and 54 parts by weight of the isocyanate compound solution (A1), 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B3). A two-component polyurethane adhesive was prepared in the same manner as in Example 1 except that 4.0 parts by weight of the isocyanate compound solution (A2) was used. At that time, 0.1 part by weight of AO-60 was blended in advance with the isocyanate compound solution (A2) with respect to 100 parts by weight of the two-component polyurethane adhesive.

  In addition, a laminate was evaluated by the same method as in Example 1. The evaluation results are shown in Table 1.

Example 5
In a 2 liter autoclave equipped with stirring blades, 1000 ml of methanol, 300 g of ethylene-vinyl acetate copolymer EVA-2, and 13.4 g of sodium methoxide were placed, heated to 50 ° C., and subjected to saponification reaction for 0.5 hour. went. After the reaction, the content was filtered, washed with methanol, neutralized, washed with water, and vacuum dried to obtain a saponified ethylene-vinyl acetate copolymer (hereinafter referred to as EVAOH-4). The obtained EVAOH-4 had a vinyl acetate residue unit content of 25% by weight, a vinyl alcohol residue unit of 1.4 mol%, and MFR = 390 g / 10 min.

  A 0.5 liter separable flask was charged with 113 g of toluene and 20 g of the resulting EVAOH-4, heated to 110 ° C. with stirring and dissolved over 1 hour, and saponified ethylene-vinyl acetate copolymer. (B4) was obtained.

  Then, instead of 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) and 54 parts by weight of the isocyanate compound solution (A1), 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B4). A two-component polyurethane adhesive was prepared in the same manner as in Example 1 except that 26 parts by weight of the isocyanate compound solution (A2) was used.

  Moreover, it evaluated by the method similar to Example 1 except having used the base material AL-1 and PET-1 instead of the base material PET-1, and having set it as the bonding laminated body. The evaluation results are shown in Table 1.

Comparative Example 1
113 g of toluene and 20 g of EVA-3 were placed in a 0.5 liter separable flask, heated to 110 ° C. with stirring, and dissolved over 1 hour to obtain an ethylene-vinyl acetate copolymer solution.

  Then, instead of 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) and 54 parts by weight of the isocyanate compound solution (A1), 100 parts by weight of the ethylene-vinyl acetate copolymer solution, the isocyanate compound solution A mixed solution was prepared in the same manner as in Example 1 except that (A1) was 54 parts by weight.

  In addition, a laminate was evaluated by the same method as in Example 1. The evaluation results are shown in Table 1. The initial adhesive strength was poor.

Comparative Example 2
Instead of 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) and 54 parts by weight of the isocyanate compound solution (A1), 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) Except for the above, a laminate was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1. The initial adhesive strength was poor.

Comparative Example 3
Example 1 except that 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) and 54 parts by weight of the isocyanate compound solution (A1) were used instead of 100 parts by weight of the isocyanate compound solution (A2). A laminate was evaluated by the same method. The evaluation results are shown in Table 1. The initial adhesive strength was poor.

実施例６
実施例３で得られた積層体を太陽電池用バックシートとして用いた。下から、ガラス基板（北陸板硝子製）／封止膜／シリコンウェハー／封止膜／実施例３の積層体の順に重ねて、遠赤外加熱炉（テーピ熱学株式会社製）を用い、温度１００℃で５分間仮接着した後、温度１５０℃に設定したオーブン中で２０分間熱接着し、太陽電池相当の積層体を作製した。得られた太陽電池相当の積層体は各層の接着性が良いものであった。

Example 6
The laminate obtained in Example 3 was used as a solar cell backsheet. From the bottom, the glass substrate (made by Hokuriku plate glass) / sealing film / silicon wafer / sealing film / layered body of Example 3 is stacked in this order, and a far-infrared heating furnace (manufactured by Tapi Thermal Engineering Co., Ltd.) is used. After temporary adhesion at 100 ° C. for 5 minutes, thermal adhesion was carried out for 20 minutes in an oven set at a temperature of 150 ° C. to produce a laminate equivalent to a solar cell. The obtained laminate corresponding to the solar cell had good adhesion between the layers.

Example 7
Instead of 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B1) and 54 parts by weight of the isocyanate compound solution (A1), 100 parts by weight of the saponified ethylene-vinyl acetate copolymer solution (B3), A laminate was evaluated in the same manner as in Example 1 except that the isocyanate compound solution (A1) was 0.09 part by weight. The evaluation results are shown in Table 1.

Example 8
Instead of 100 parts by weight of saponified ethylene-vinyl acetate copolymer solution (B1) and 54 parts by weight of isocyanate compound solution (A1), 100 parts by weight of saponified ethylene-vinyl acetate copolymer solution (B4), Isocyanate compound solution (A2) is blended at a ratio of 0.2 parts by weight to prepare a two-component polyurethane adhesive, and base materials AL-1 and PET-1 are bonded together instead of base material PET-1. The evaluation was performed in the same manner as in Example 1 except that the laminated body was used. The evaluation results are shown in Table 1.

Example 9
A saponified ethylene-vinyl acetate copolymer solution (B3) was blended at a ratio of 100 parts by weight and an isocyanate compound solution (A2) of 4.0 parts by weight to prepare a two-component polyurethane adhesive.

  Using the obtained two-component polyurethane adhesive as an adhesive for laminating, PET-1 and PET-1 as base materials are pasted by a coater ((trade name) INVEX pilot coater, manufactured by Inoue Metal Industry Co., Ltd.). A laminated laminate was obtained. The drying temperature was 80 ° C., and aging was performed at 100 ° C. for 24 hours.

  When the initial adhesive strength of the obtained laminate was measured, it was 13 N / 25 mm, indicating an excellent adhesive strength. Moreover, when the obtained laminated body was subjected to a wet heat test and the adhesive strength after the wet heat test was measured, it showed excellent wet heat resistance of 12 N / 25 mm.

  The two-component polyurethane adhesive of the present invention is excellent in adhesiveness and durability, and is extremely useful in various fields, particularly in the field of bonding to form a laminate.

Claims (10)

A two-component polyurethane adhesive comprising a liquid (A) comprising an isocyanate compound and a liquid (B) comprising a saponified ethylene-vinyl acetate copolymer. The two-component polyurethane adhesive according to claim 1, wherein the liquid (A) is a liquid containing a trifunctional or higher functional isocyanate compound. The two-component polyurethane adhesive according to claim 1 or 2, wherein the liquid (A) is a liquid composed of an aromatic isocyanate compound. The liquid (B) is a liquid composed of a saponified ethylene-vinyl acetate copolymer containing 0.01 to 10 mol% of vinyl alcohol residue units. Two-component polyurethane adhesive. The liquid (B) is a liquid composed of a saponified ethylene-vinyl acetate copolymer containing 15 to 80% by weight of vinyl acetate residue units. Liquid polyurethane adhesive. The two-component polyurethane adhesive according to any one of claims 1 to 5, wherein the liquid (A) is blended and used at a ratio of 0.01 to 150 parts by weight per 100 parts by weight of the liquid (B). Agent. The two-component polyurethane adhesive according to any one of claims 1 to 6, which is an adhesive for laminating. The two-component polyurethane adhesive according to any one of claims 1 to 7, which is an adhesive for a polyester film. A laminate comprising a base material adhered by the two-component polyurethane adhesive according to any one of claims 1 to 8. A back sheet for a solar cell, comprising the laminate according to claim 9.