TW201406861A - Heat sealing agent, laminate using same, and solar cell module - Google Patents

Abstract

The present invention provides a heat sealing agent characterized by containing: a urethane resin (A); a polyolefin resin (B); a cross-linking agent (C) including at least one type selected from a group comprising a melamine compound, an epoxy compound, an oxazoline compound, a carbodiimide compound, and an isocyanate compound; a compound (D) having a molecular weight of 20-3,000 and having a primary amino group or a hydrazide group; and an aqueous medium (E). This heat sealing agent has excellent adhesiveness to a base material, and can form a heat sealing layer comprising a level of heat and moisture resistance at which a reduction in adhesiveness is not caused by the effects of heat, etc.

Description

Heat sealant, laminated body using the same, and solar battery module

The present invention is based, for example, on the adhesion of a backsheet layer of a solar cell module, and with respect to a heat sealant, it can be used for adhesion of a wide variety of components, particularly polar and non-polar components.

As a member used in the manufacture of automobile parts, home electric appliances, solar power generation equipment, etc., it is known that it has excellent weather resistance or water resistance, and is widely used in an ethylene-vinyl acetate resin or a polymer having excellent formability and reproducibility. A member composed of an olefin resin or the like.

In general, the ethylene-vinyl acetate resin is easily deteriorated by exposure to heat, water (moisture), or the like, and is insufficient in terms of moist heat resistance. Therefore, a composite member in which a glass or a polyethylene terephthalate substrate or the like is bonded to a member made of the ethylene-vinyl acetate resin is usually used, and most of them are heat-resistant heat which can suppress the deterioration level. The case where the ethylene-vinyl acetate resin substrate is imparted.

However, since the base material made of an ethylene-vinyl acetate resin or the like is generally a substrate having a low surface polarity, for example, even if an ethylene-vinyl acetate resin substrate or the like is bonded to the glass or the like using an adhesive, The interface between the surface of the ethylene-vinyl acetate resin substrate or the like and the adhesive layer is likely to be peeled off, or even if it can be temporarily adhered, the adhesive layer is deteriorated by the influence of heat or water, and peeling occurs over time. The situation.

On the other hand, by adjusting the composition of the adhesive, the adhesion to the non-polar substrate such as ethylene-vinyl acetate resin can be improved. However, in the case where the substrate to be bonded is a polar substrate such as the glass or polyethylene terephthalate substrate, the adhesion between the polar substrate and the adhesive layer is lowered, and there is still The situation caused by the passage of time.

In this manner, it has been found to be technically difficult to provide an adhesive having superior adhesion to both a non-polar substrate and a polar substrate.

As an adhesive having superior adhesion, it is conventionally contained, for example, in an aqueous medium containing an acid-modified polyolefin resin, a polyurethane resin, a fatty acid guanamine, and a specific ratio. The adhesive comprising the aqueous dispersion of the olefin-bonding material is excellent in adhesion to the thermoplastic resin substrate (see, for example, Patent Document 1).

However, since the adhesive is not excellent in adhesion to both the non-polar substrate and the polar substrate as described above, the interface between any of the substrate and the adhesive layer may be peeled off over time. The situation.

In addition, since the adhesive is easily deteriorated by exposure to heat, water (moisture), etc., it is affected by heat, water, or the like, and the adhesive layer is deteriorated or peeled off over time. As a result, there will be A situation that causes the substrate itself to deteriorate.

However, in the case where the substrate is bonded using the adhesive as described above, it is usually usually applied to the surface of the substrate on either side by the adhesive before the bonding, and then the substrate on the other side. Lamination The surface of the adhesive layer having an adhesive feeling before the adhesive layer is completely cured is hardened and adhered thereto.

However, such a method is required to apply an adhesive or remove a solvent contained in the adhesive at a work site where the substrate is bonded, and the production efficiency of the composite member is remarkably lowered.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-235289

The problem to be solved by the present invention is to provide a heat sealant, a laminate using the same, and a solar cell module capable of forming a heat seal layer, for example, a substrate of any of a polar substrate and a non-polar substrate. It is excellent in adhesion and has heat and humidity resistance which is affected by heat or water (moisture) and does not cause a decrease in adhesion.

Further, the subject of the present invention is to provide a heat sealant, a laminate using the same, and a solar cell module capable of forming a heat seal layer, for example, a substrate of any one of a polar substrate and a non-polar substrate. All have excellent adhesion, and are resistant to heat and humidity caused by heat or water (moisture), etc., without causing deterioration or adhesion, and by applying the heat sealant to one side in advance. After the surface of the substrate is dried to form a crosslinked heat seal layer, the substrate on the other side is placed on the heat seal layer, and the substrate can be adhered by heating.

In order to solve this problem, the present inventors have found that a heat sealant containing a specific compound having a primary amine group or a sulfhydryl group bonded thereto can solve the problem.

That is, the present invention relates to a heat sealant characterized by containing a urethane resin (A), a polyolefin resin (B), and containing a compound selected from the group consisting of a melamine compound and an epoxy compound. More than one crosslinking agent (C) of the group consisting of an oxazoline compound, a carbodiimide compound and an isocyanate compound, a compound (D) having a molecular weight of 20 to 3,000 having a primary or tertiary group, and an aqueous medium (E).

The heat sealant of the present invention is not only an ethylene-vinyl acetate resin or a polyolefin resin which has been widely used in the industry, but also has excellent adhesion to a substrate composed of polyethylene terephthalate or the like. For example, it can be used for bonding of various non-polar substrates or polar substrates, surface coating of such substrates, and the like.

Further, the heat sealant of the present invention is a laminate (composite member) obtained by laminating various substrates, and in particular, can significantly improve the production efficiency of the solar cell module.

[Formation of the Invention]

The heat sealant of the present invention is characterized by comprising a urethane resin (A), a polyolefin resin (B), and a component selected from the group consisting of a melamine-containing compound and an epoxy compound. More than one crosslinking agent (C) of the group consisting of an oxazoline compound, a carbodiimide compound and an isocyanate compound, a compound (D) having a molecular weight of 20 to 3,000 having a primary or tertiary group, and an aqueous medium (E).

Preferably, the urethane resin (A) and the polyolefin resin (B) are each independently dispersed or dissolved in the aqueous medium (E), and may be formed even if one of the portions is bonded to form resin particles. The so-called core-shell type composite resin particles.

Among these, the urethane resin (A) and the polyolefin resin (B) preferably form resin particles independently of each other and can be dispersed in the aqueous medium (E).

The resin particles are preferably an average particle diameter in the range of 10 nm to 500 nm in terms of improving the smoothness of the coating film which can be formed. The average particle diameter herein means an average particle diameter on a volume basis measured by a dynamic light scattering method.

The mass ratio of the urethane resin (A) to the polyolefin resin (B) [urethane resin (A) / polyolefin resin (B)] is preferably in the range of 9/1 to 2/8 More preferably in the range of 8/2 to 3/7, further preferably in the range of 8/2 to 5/5, in order to make the superior heat and humidity resistance and the superior adhesion to various substrates coexist The aspect is further preferred.

Further, the urethane resin (A) and the polyolefin resin (B) are contained in an amount of from 5% by mass to 70% by mass based on the total amount of the heat sealant of the present invention, and that the heat sealant is good. It is preferable in terms of dispersion stability and coating workability, and more preferably in the range of 20% by mass to 70% by mass.

Moreover, from the good dispersion in the aqueous medium (E) From the viewpoint of characterization, the urethane resin (A) and the polyolefin resin (B) may also have a hydrophilic group. As the hydrophilic group, for example, a polyoxyethylene structure which is an anionic group, a cationic group, and a nonionic group can be used, and among them, an anionic group is more preferably used.

As the anionic group, for example, a carboxyl group, a carboxy group, a sulfonic acid group, a sulfonate group or the like can be used. Among them, a part or all of a carboxyl group or a sulfonate group neutralized by a base compound is used, and good water is used. The dispersibility is preferably given to the urethane resin (A) or the polyolefin resin (B).

Further, as the cationic group, for example, a tertiary amino group or a cationic group after neutralization using an oxide or a quaternizing agent can be used.

Further, as the nonionic group, for example, a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a poly(ethylene oxide-propylene oxide) group, and a polyoxyethylene-polyoxypropylene group can be used. Alkyl.

The urethane resin (A) is preferably used in an amount of more than 3,000, 300,000 or less from the viewpoint of imparting excellent adhesion and durability to the polar substrate (I) or the non-polar substrate (II). The weight average molecular weight of the person.

In addition, when the urethane resin (A) is used as a crosslinking agent (C) to be described later, an epoxy group or a hydrolyzable alkylene group which can be bonded thereto is used. The functional group-reactive functional group [X] is preferred in that it provides a heat sealant which is superior in heat and heat resistance and which is excellent in adhesion to various substrates.

The functional group [X] may, for example, be a carboxyl group, a hydroxyl group or an amine group. Further, in order to stabilize the urethane resin (A) and the polyolefin resin (B) in the aqueous medium (E), a hydrophilic group-containing urethane such as an anionic group or a cationic group is used. In the case of a resin or a polyolefin resin, a carboxyl group as the hydrophilic group or a carboxyl group which neutralizes the carboxyl group using a basic compound or the like is also used as the functional group in the crosslinking reaction [X]. The effect of the reaction can be partially reacted with one of the crosslinking agents (C). Therefore, as the functional group [X], an anionic group such as a carboxyl group or a sulfonate group which is neutralized by a base compound or the like, which functions as the hydrophilic group, or an acid group can be used. a cationic group such as an amine group neutralized by the compound. The functional group [X] is preferably a carboxyl group or a carboxyl group in the above.

In particular, when a carboxyl group is used as the functional group [X], it is preferable to use an acid value of 5 to 70 as the urethane resin (A), and to improve the adhesion to various substrates. Good use has an acid price of 5 to 50. Further, as the polyolefin resin (B), those having an acid value of 5 to 300 are preferably used, and those having an acid value of 10 to 250 are more preferably used.

As the urethane resin (A), an amine group having a urea bond formed by reacting a urethane resin having an isocyanate group with a compound (a3) having a primary amino group or a mercapto group can be used. Acid ester resin (A-1). Thereby, the adhesion to various substrates can be further improved. In particular, it has been found that the surface of the substrate having the polar substrate (I) or the like which has been subjected to corona treatment or the like has remarkably superior adhesion. It is presumed that this is because a carbonyl group is formed on the surface of the substrate by the corona treatment or the like, and such a carbonyl group forms a bond with a nitrogen atom forming the urea bond.

As the urethane resin (A-1), a urethane resin having an isocyanate group and a compound (a3) having a primary amino group or a mercapto group are preferably used, and the compound (a3) is bonded thereto. The equivalent ratio of the isocyanate group bonded to the urethane resin of the first-order amine group and the mercapto group [the total of the amine group and the mercapto group bonded to the compound (a3) / the amine carbamate The isocyanate group bonded by the ester resin is in the range of 0.8 to 2, and the obtained product is obtained by using a reaction which is obtained by using 1 to 2, for example, in a polar substrate and a non-polar substrate. The substrate of any of them is more preferably formed into a heat seal layer having particularly excellent adhesion, and more preferably more than 1, 2 or less, particularly preferably from 1.05 to 1.5.

As the urethane resin (A), for example, a reaction obtained by reacting a polyol (a1) with a polyvalent isocyanate (a2) can be used.

As the polyol (a1), for example, a polyester polyol, a polycarbonate polyol, a polyether polyol, a polyolefin polyol, or the like can be used alone or in combination of two or more.

Among them, in order to further improve the adhesion to the nonpolar substrate (II), a polyether polyol is preferably used.

As the polyether polyol which can be used for the polyol (a1), for example, one or two or more compounds having two or more active hydrogen atoms can be used as a starter to form an alkylene oxide polymerizer.

As the initiator, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6- can be used. Hexanediol, bisphenol A, glycerol, trimethylolethane, trimethylolpropane, and the like.

As the alkylene oxide, for example, ethylene oxide or a ring can be used. Oxypropane, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and the like.

As the polyether polyol which can be used for the polyol (a1), specifically, polyoxytetramethylene glycol formed by ring-opening tetrahydrofuran is preferably used.

As the polyether polyol, it is preferred to use a number average molecular weight of 500 to 3,000 in terms of further improving the adhesion to the polar substrate (I) or the nonpolar substrate (II).

The polyether polyol is preferably used in the range of 1,000 to 3,000 with respect to the entire polyol (a1) used in the production of the urethane resin (A).

Further, as the polyester polyol which can be used for the polyol (a1), for example, an esterification reaction of a low molecular weight polyol with a polybasic acid or a cyclic ester compound such as ε-caprolactone can be used. The polyester obtained by the ring polymerization or the copolymerized polyester or the like.

As the low molecular weight polyol, for example, ethylene glycol or propylene glycol having a molecular weight of about 50 to 300, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and 1 An aliphatic polyol such as 3-butanediol; or a polyhydric alcohol having an aliphatic cyclic structure such as cyclohexanedimethanol; a bisphenol compound such as bisphenol A or bisphenol F; and the alkylene oxides An aromatic structure-containing polyol such as an adduct.

Further, as the polybasic acid which can be used for the production of the polyester polyol, for example, an aliphatic polybasic acid such as succinic acid, adipic acid, sebacic acid or dodecanedicarboxylic acid; or terephthalic acid can be used. And aromatic polybasic acids such as isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, and the like An acid anhydride or an ester-forming derivative or the like.

As the polyester polyol, those having a number average molecular weight in the range of 200 to 5,000 are preferably used.

Further, as the polycarbonate polyol used for the polyol (a1), for example, those obtained by reacting a carbonate with a polyol or phosgene with bisphenol A or the like can be used.

As the carbonate, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclic carbonate, diphenyl carbonate or the like can be used.

As the polyol reactive with the carbonate, for example, ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 3- can be used. a lower molecular weight diol having a molecular weight of about 50 to 2,000, such as methyl-1,5-pentanediol, 1,4-cyclohexanediol, 1,6-hexanediol, cyclohexanedimethanol; or Polyethylene glycol, polypropylene glycol, or polyester polyol such as polyhexamethylene adipate.

As the carbonate polyol, a non-polar substrate (II) composed of ethylene-vinyl acetate resin or polypropylene is used without using a mass average molecular weight in the range of 500 to 4,000 without impairing superior moist heat resistance. It is better in terms of adhesion.

Further, as the polyolefin polyol which can be used for the polyol (a1), for example, a polyethylene polyol, a polypropylene polyol, a polyisobutylene polyol, a hydrogenated (hydrogenated) polybutadiene polyol, and a polyethylene can be used. Hydrogen (hydrogenated) polyisobutylene polyol.

Moreover, from the viewpoint of imparting good water dispersion stability to the urethane resin (A), the polyol (a1) is used in addition to the above. It is also possible to use a polyol having a hydrophilic group in combination.

As the polyol having a hydrophilic group, for example, a polyhydric alcohol having an anionic group other than the above polyhydric alcohol, a polyhydric alcohol having a cationic group, and a polyhydric alcohol having a nonionic group can be used. Among them, a polyol having an anionic group or a polyol having a cationic group is preferably used, and a polyol having an anionic group is more preferably used.

As the polyol having an anionic group, for example, a polyol having a carboxyl group or a polyol having a sulfonic acid group can be used.

As the polyol having a carboxyl group, for example, 2,2'-dimethylolpropionic acid, 2,2'-dimethylolbutanoic acid, 2,2'-dimethylol-n-butyric acid, 2, can be used. 2'-Dimethylolvaleric acid or the like, among which 2,2'-dimethylolpropionic acid is preferably used. Further, a polyester polyol having a carboxyl group obtained by reacting the polyol having a carboxyl group with various polybasic acids can also be used.

As the polyhydric alcohol having a sulfonic acid group, for example, 5-sulfonic acid isophthalic acid, sulfonic acid terephthalic acid, 4-sulfonic acid phthalic acid, 5-[4-sulfonate a dicarboxylic acid such as acid phenoxy]isophthalic acid or a salt thereof, and a low molecular weight exemplified as a manufacturer of the polyester polyol (a1-1) having the aromatic structure A polyester polyol obtained by reacting a polyol.

The polyol having a carboxyl group or the polyol having a sulfonic acid group is preferably used in such a range that the acid value of the urethane resin (A) is from 10 to 70, more preferably from 10 to 50. . In addition, the acid value in the present invention is a theoretical value calculated based on the amount of the acid group-containing compound having a carboxyl group-containing polyol or the like used in the urethane resin (A).

The anionic group neutralizes some or all of these by a basic compound or the like, and is preferable in that good water dispersibility is found.

As the base compound which can be used for neutralizing the anionic group, for example, an organic amine having a boiling point of 200 ° C or higher, such as ammonia, triethylamine, saccharin, monoethanolamine or diethanolamine, or containing a hydroxide can be used. A metal hydroxide such as sodium, potassium hydroxide or lithium hydroxide. From the viewpoint of improving the water dispersion stability of the obtained heat sealant, the base compound is preferably used in the range of a base compound/anionic group = 0.5 to 3.0 (mole ratio), more preferably Be used within the range of 0.8 to 2.0 (Morbi).

Further, as the cationic group, for example, a polyol having a tertiary amino group can be used, and specifically, N-methyldiethanolamine or a compound having two epoxy groups in one molecule can be reacted with a secondary amine. The obtained polyol and the like.

The cationic group is preferably partially or wholly neutralized with an acidic compound such as formic acid, acetic acid, propionic acid, succinic acid, glutaric acid, tartaric acid or adipic acid.

Further, it is preferred that the third-stage amine group as the cationic group be partially or entirely 4-staged. As the above-mentioned fourth-stage agent, for example, dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride or the like can be used, and dimethyl sulfate is preferably used.

Further, as the polyol having a nonionic group, a polyoxyethylene structure or the like can be used.

For the manufacture of the urethane resin (A) The polyol having a hydrophilic group is preferably used in the range of 0.3% by mass to 10% by mass based on the total amount of the polyol (a1).

Further, in addition to the polyol, other polyols can be used as the polyol (a1) as necessary.

As the other polyol, for example, ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1 can be used. a lower molecular weight polyol such as 5-pentanediol, 1,4-cyclohexanediol, 1,6-hexanediol or cyclohexanedimethanol.

In the present invention, neopentyl glycol or the like is preferably used in order to further improve the adhesion of the heat sealant to various substrates.

As the polyvalent isocyanate (a2) which can be reacted with the polyol (a1), for example, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate or carbodiimide can be used. Aromatic polyisocyanate such as diphenylmethane diisocyanate, prophenyl diisocyanate, phenyl diisocyanate, tolyl diisocyanate, naphthalene diisocyanate; or hexamethylene diisocyanate, 2,6-diamine An aliphatic polyisocyanate such as diacetic acid diisocyanate, xylene diisocyanate or tetramethyl xylene diisocyanate; an aliphatic cyclic structure such as cyclohexane diisocyanate, dicyclohexylmethane diisocyanate or isophorone diisocyanate; Polyisocyanate.

The urethane resin (A) can be produced by, for example, reacting the polyol (a1) with the polyvalent isocyanate (a2) in the absence of a solvent or an organic solvent.

Further, the urethane resin (A) is a combination of an isocyanate group bonded to a urethane resin and a group 1 or an amine group. In the case of the urethane resin (A-1) obtained by the reaction of the substance (a3), for example, by reacting the polyol (a1) with the polyvalent isocyanate (a2) in the absence of a solvent or in the presence of an organic solvent In the case of producing a urethane resin having an isocyanate group, and then having a hydrophilic group in the urethane resin, a part or all of the hydrophilic group may be neutralized into the aqueous medium (E) if necessary. When it is made to be water-based, it can be produced by mixing with a compound (a3) having a primary amino group or a mercapto group, and reacting with an isocyanate group bonded to the urethane resin.

For example, the reaction of the polyol (a1) with the polyisocyanate (a2) is preferably an equivalent ratio of the isocyanate group bonded to the polyisocyanate (a2) to the hydroxyl group bonded to the polyol (a1) at 1.05 to 2.5. It is carried out within the range, preferably in the range of 1.1 to 2.

Moreover, as an organic solvent which can be used for the production of the urethane resin (A), for example, a ketone such as acetone or methyl ethyl ketone can be used alone; tetrahydrofuran, An ether such as an alkoxide; an acetate such as butyl acetate; a nitrile such as acetonitrile; or a guanamine such as dimethylformamide or N-methylpyrrolidone; or two or more kinds thereof.

Further, as the compound (a3) having a primary amine or a mercapto group which can be used in the production of the urethane resin (A-1) in the urethane resin (A), for example, it can be used. Anthracene or dicarboxylic acid dioxane, homodiamine urea, 1,3-bis(decylcarboxyethyl)-5-isopropylhydantoin, ethanolamine, etc.; preferably using hydrazine or dicarboxylic acid Diterpenoid or homodiamine urea is more preferable in terms of further improving the heat and humidity resistance.

As the dicarboxylic acid dioxime, for example, ruthenium, bismuth malonate, bismuth succinate, diammonium adipate, and bismuth glutarate can be used alone. One or a combination of two or more of hydrazine, azelaic acid diterpene, isophthalic acid dioxime, and β-aminolevulinium phthalate. Among them, it is preferable to use 肼 in terms of imparting superior adhesion.

The aqueous formation of the urethane resin (A) obtained by the above method can be carried out, for example, by the following method.

[Method 1] Part or all of the hydrophilic group of the urethane resin (A) obtained by reacting the polyol (a1) with the polyvalent isocyanate (a2) by neutralization or quaternization, and then pouring water to make A method in which water is dispersed, and if necessary, chain elongation is carried out to disperse the urethane resin (A) in water.

[Method 2] A urethane resin (A) obtained by reacting a polyol (a1) with a polyvalent isocyanate (a2), and a compound having a primary amino group or a thiol group if necessary (a3) The urethane resin (A) is obtained by further feeding the mixture into a reaction vessel, and elongating the chain to obtain a urethane resin (A), followed by neutralization or quaternization of the resulting urethane resin (A). A method in which one or both of the hydrophilic groups are poured into water to disperse the water.

In the [Method 1] to [Method 2], an emulsifier may also be used as necessary. Further, when water is dissolved or water is dispersed, a machine such as a homogenizer may be used as necessary.

Examples of the emulsifier include polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene sorbitol tetraoleate, and polyethylene oxide. ‧ Nonionic emulsifiers such as polyoxypropylene copolymer; fatty acid salts such as sodium oleate, alkyl sulfates, alkylbenzenesulfonates, alkanesulfonate succinates, naphthalenesulfonates, poly An anionic emulsifier such as an ethylene oxide alkyl sulfate, an alkanesulfonate sodium salt or an alkyl diphenyl ether sulfonate sodium salt; A cationic emulsifier such as a base amine salt, an alkyltrimethylammonium salt or an alkyldimethylbenzylammonium salt. Among them, an anionic or nonionic emulsifier is basically preferably used from the viewpoint of maintaining the superior storage stability of the coating agent of the present invention.

The urethane resin (A) aqueous dispersion in which the urethane resin (A) obtained by the above method is dispersed in the aqueous medium (E) is in the range of 10 to 50 with respect to the entire amount of the aqueous dispersion. The urethane resin (A) is contained in the range to improve the ease of production of the heat sealant of the present invention, and also to prepare a heat which is superior in cohesive heat resistance to superior adhesion to various substrates. The sealant is preferred.

The aqueous dispersion of the urethane resin (A) may be two or more kinds of urethane resins having different mixing compositions. Specifically, a urethane resin having a different composition of two or more kinds of polyols (a1) for producing a urethane resin can be used in combination.

Next, it is explained with respect to the polyolefin resin (B) used for manufacture of the heat-sealing agent of this invention.

As the polyolefin resin (B) used in the present invention, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene or the like can be used. A homopolymer or a copolymer or the like; specifically, polyethylene, polypropylene, polybutadiene, ethylene-propylene copolymer, natural rubber, synthetic isoprene rubber, ethylene-vinyl acetate copolymer, or the like can be used. In the case where the polyolefin resin (B) is a copolymer, it may be either a random copolymer or a block copolymer.

When necessary, the polyolefin resin (B) is preferably one having a functional group reactive with a crosslinking agent (C) to be described later, in particular, an epoxy compound. In the case of use as the crosslinking agent (C), a functional group [X] having a functional group reactive with an epoxy group or a hydrolyzable decyl group bonded to the crosslinking agent (C) is more preferably used.

In the same manner as the functional group [X] to which the urethane resin (A) is bonded, a carboxyl group or the like is exemplified, and among them, a carboxyl group is preferred. Further, the functional group [X] may be the same functional group as the hydrophilic group to which the polyolefin resin (B) is bonded. Specifically, when a carboxyl group or a carboxyl group of an anionic group is used as the hydrophilic group, the carboxyl group or the like can also function as the functional group [X] at the time of the crosslinking reaction.

As the polyolefin resin (B) having a carboxyl group as the functional group [X], those obtained by reacting the above-exemplified polyolefin resin with an unsaturated carboxylic acid or reacting with an ethylene monomer are preferably used. Or a so-called modified polyolefin resin such as chlorinated.

For example, the carboxyl group of the functional group [X] can be introduced into the polyolefin resin (B) by reacting a polyolefin resin with an unsaturated dicarboxylic acid such as maleic acid (anhydride).

Examples of the unsaturated dicarboxylic acid include maleic acid, fumaric acid, methylene succinic acid, dihydroxy benzoic acid, and the like; and an unsaturated dicarboxylic acid ester ( Butylene maleate, dibutyl maleate, butyl methylene succinate, etc.; one or more of these may be used. Among these, maleic anhydride is preferred.

The polyolefin resin (B) modified with the unsaturated carboxylic acid has an acid value in the range of 5 to 250, and is prevented from being deteriorated by the heat-resistant layer caused by heat or water (moisture), and is prevented. It is preferred to reduce the adhesion of various substrates.

For example, the modification of the polyolefin resin can be carried out by heating or the like by heating the unsaturated resin such as the above-mentioned polyolefin resin or maleic acid.

In addition, the polyolefin resin (B) is preferably used in order to prevent deterioration of the resin hardened layer caused by heat, water (moisture), or the like, and to prevent adhesion to various substrates. A weight average molecular weight of 20,000 to 500,000. Also, the weight average molecular weight means a value measured by a coagulation permeation chromatography (GPC).

Next, it demonstrates about the crosslinking agent (C) used by this invention.

The crosslinking agent (C) can be selected from the group consisting of a melamine compound, an epoxy compound, and One or more of the group consisting of an oxazoline compound, a carbodiimide compound, and an isocyanate compound.

Among them, one or more selected from the group consisting of a melamine compound, an epoxy compound, and an isocyanate compound are preferably used in combination, and a melamine compound and an epoxy compound are more preferably used in combination.

As the melamine compound, an alkylated methylol melamine resin (c1) is particularly preferably used.

The alkylated methylol melamine resin (c1) can form a crosslinked structure by self-crosslinking reaction. Further, when the functional group [X] bonded to the urethane resin (A) and the polyolefin resin (B) reacts with the epoxy compound to form a functional group such as a hydroxyl group, the hydroxyl group and the hydroxyl group are The alkylated hydroxymelamine resin (c1) will react to form a crosslinked structure.

As the alkylated methylol melamine resin (c1), for example, a methylolated melamine resin or methanol or butanol can be used. A lower alcohol (an alcohol having 1 to 6 carbon atoms) is reacted. Specifically, an alkylated methylol melamine resin containing a quinone imine group or an alkylated methylol melamine resin containing an amine group can be used.

As the methylol melamine resin, for example, an amino group-containing hydroxymethyl type melamine resin obtained by condensing melamine and formaldehyde, an imido group-containing hydroxymethyl type melamine resin, and a trimethoxy hydroxymethyl type melamine resin are preferably used. As the hexamethoxymethylol type melamine resin or the like, a trimethoxymethylol type melamine resin or a hexamethoxymethylol type melamine resin is preferably used.

The alkylated methylol melamine resin (c1) is preferably in the range of from 3% by mass to 50% by mass based on the total mass of the urethane resin (A) and the polyolefin resin (B). It is preferably used in the range of 3 mass% to 30 mass%. Thereby, it is not affected by heat or water (moisture), etc., and does not cause deterioration of the heat seal layer or a decrease in the adhesion force, and has superior heat and humidity resistance and superiority to various substrates. Convergence will be possible.

Further, the epoxy group used in the crosslinking agent (C) can be bonded to a functional group bonded to either or both of the urethane resin (A) and the polyolefin resin (B) [X The reaction forms a crosslinked structure, and as a result, it can be used in terms of imparting excellent heat resistance and excellent adhesion to various substrates.

In the present invention, the alkylated methylol melamine resin (c1) and the epoxy compound are used in combination as the crosslinking agent (C), and the superior heat and humidity resistance is superior to that of various substrates. Sexual coexistence is particularly good.

Further, an epoxy compound is used as the crosslinking agent (C). In the form of a urethane resin (A) and the polyolefin resin (B), a functional group capable of reacting with a functional group such as an epoxy group or a hydrolyzable decyl group bonded to the epoxy compound [X] By. Specifically, the functional group to which the epoxy compound is bonded is an epoxy group, or an alkoxyalkyl group or a hydrolyzable alkylene group such as a decyl group.

As the epoxy compound, it is preferred to use 2 to 5 epoxy groups, and it is more preferable to use 3 to 4 ones.

As the epoxy compound, for example, an epoxy resin of a bisphenol A epichlorohydrin type, an ethyl epoxide ester, a polyethylene glycol diepoxypropyl ether, or a glycerol diepoxypropyl group can be used. Ether, glycerol triepoxypropyl ether, 1,6-hexanediol epoxypropyl ether, trimethylolpropane triepoxypropyl ether, diepoxypropylaniline, diamine epoxypropyl Amine, N,N,N',N'-tetraepoxypropylm-xylylenediamine, 1,3-bis(N,N'-diamineglycidylmethyl)cyclohexane, and the like.

Among them, the epoxy compound is preferably used in an epoxy equivalent of from 100 to 300, and more preferably, trimethylolpropane polyepoxypropyl ether is used, or C is more preferably used. One or more of the triol triepoxypropyl ethers are further preferably trimethylolpropane triepoxypropyl ether or glycerol triepoxypropyl ether.

Further, as the epoxy compound, an epoxy compound having a hydrolyzable alkylene group can also be used.

As the epoxy compound having a hydrolyzable alkylene group, for example, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyltriethoxydecane, or 3-glycidoxypropane can be used. Propylmethyldiethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 2-(3,4- Epoxycyclohexyl)ethyltrimethoxydecane, 2-(3,4-epoxycyclohexyl)ethyltriethoxydecane, and the like.

Further, as the crosslinking agent (C), the mass of the epoxy group (molar number) to which the epoxy compound is bonded is preferably the urethane resin (A) and the polyolefin resin (B). The ratio of the total mass (molar number) of the functional group [X] to which the bond is bonded [the mass of the epoxy group (the molar number) / the total mass of the functional group [X] (the molar number) becomes Use within the range of 5/1 to 1/5. Thereby, by heat or the like, since the heat seal layer having a strong crosslink density can be formed at the time of further hardening, the heat seal layer is not deteriorated by the influence of heat or water (moisture) or the like. Or the reduction of the adhesion force can make the superior heat and humidity resistance and the superior adhesion to various substrates coexist.

The use ratio [the mass of the epoxy group / the total mass of the functional group [X]] is preferably in the range of 2/1 to 1/5, which makes the superior heat and humidity resistance superior to various substrates. The adhesion is better.

Further, the alkylated methylol melamine resin (c1) and the epoxy compound are preferably in a mass ratio in terms of a superior moisture and heat resistance and superior adhesion to various substrates. The base methylol melamine resin (c1) / the epoxy compound is used in the range of 7/1 to 1/4, more preferably in the range of 5/1 to 1/4.

Further, as the crosslinking agent (C), in addition to the above, for example, 2,2'-bis(2- can also be used. Oxazoline), 2,2'-methylene double (2- Oxazoline), 2,2'-extended ethyl bis (2- Oxazoline), 2,2'-trimethylene double (2- Oxazoline), 2,2'-tetramethylene double (2- Oxazoline), 2,2'-hexamethylene double (2- Oxazoline), 2,2'-octamethylene double (2- Oxazoline), 2,2'-extended ethyl bis(4,4'-dimethyl-2- Oxazoline), 2,2'-p-phenylene bis(2- Oxazoline), 2,2'-interphenylene bis(2- Oxazoline), 2,2'-meta-phenyl bis(4,4'-dimethyl-2- Oxazoline), sulfurized double (2- Oxazoline cyclohexane), sulfurized double (2- Oxazoline Alkane), EPOCROS WS-500, WS-700 (Japan Catalyst Co., Ltd.), etc. An oxazoline compound, poly[phenylene bis(dimethylmethylene)carbodiimide] or poly(methyl-1,3-phenylene carbodiimide); in commercial products, For example, CARBODILTE V-02, V-04, E-01, E-02, etc. (Nissin Spinning Co., Ltd.), UCARLINK XL-29SE, XL-29MP (UNION CARBIDE) can also be used. Imine compound; toluene diisocyanate, chlorophenyl diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate The isocyanate monomer such as an isocyanate monomer; or an isocyanate compound obtained by adding the monomer to a compound such as an alcohol compound having a divalent or higher valence of trimethylolpropane or the like.

The crosslinking agent (C) is preferably used in an amount of from 1% by mass to 50% by mass based on the total mass of the urethane resin (A) and the polyolefin resin (B), more preferably 3 It is used in the range of 3% by mass to 30% by mass, and more preferably in the range of 3% by mass to 30% by mass.

Next, the compound (D) having a molecular weight of 20 to 3,000 having a primary amino group or a mercapto group used in the present invention will be described.

The compound (D) having a molecular weight of 20 to 3,000 having a primary amino group or a mercapto group used in the heat-sealing agent of the present invention is used in imparting superior adhesion to various substrates.

The compound (D) having a molecular weight of 20 to 3,000 having a 1-stage amine group or a mercapto group is preferably blended with the urethane resin (A) or the polyolefin resin. (B) or the like is dispersed or dissolved in the aqueous medium (E). Further, the compound (D) may also function as the compound (a3) having a primary amino group or a mercapto group, and a part thereof may be reacted with a part of the isocyanate of the urethane resin (A).

As the compound (D), those having a molecular weight of 3,000 or less are preferably used, and in terms of increasing the crosslinking density and further improving the durability, it is more preferably used in an amount of from 20 to 1,000. Further, the molecular weight of the compound (D) is a value based on the sum of the atomic weights of the atoms constituting the compound.

As the compound (D), for example, hydrazine, divalent dicarboxylic acid, homodiamine urea, 1,3-bis(decylcarboxyethyl)-5-isopropylhydantoin, ethanolamine, or the like can be used. It is preferable to use hydrazine or dicarboxylic acid di- or di-diamine urea, and it is more preferable to use divalent dicarboxylic acid in terms of further improving heat and humidity resistance.

As the dicarboxylic acid diterpene, for example, diammonium malonate, diterpene succinate, diammonium adipate, diammonium glutarate, diterpene sebacate, m-benzoic acid can be used. One type or a combination of two or more kinds of diterpene formate or β-aminolevulinium hydride. Among them, diterpene adipic acid is preferably used in imparting superior adhesion.

From the viewpoint of imparting superior adhesion to various substrates, the compound (D) having a primary amino group or a mercapto group is preferably 0.1 mass with respect to 100 parts by mass of the urethane resin (A). It is used in the range of % to 20% by mass.

Next, the aqueous medium (E) used in the present invention will be described.

The aqueous medium (E) used in the present invention may, for example, be water, an organic solvent mixed with water, and a mixture thereof. As mixed with water Examples of the organic solvent include alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone and methyl ethyl ketone; and polyalkylenes such as ethylene glycol, diethylene glycol, and propylene glycol. An alcohol; an alkyl ether of a polyalkylene glycol; an indoleamine such as N-methyl-2-pyrrolidone or the like. In the present invention, water alone may be used, or a mixture of water and an organic solvent mixed with water may be used, or only an organic solvent mixed with water may be used. From the viewpoint of safety or load on the environment, it is preferably only water, or a mixture of water and an organic solvent mixed with water, and particularly preferably water.

The aqueous medium (E) is contained in an amount of from 10% by mass to 80% by mass based on the total amount of the heat-sealing agent of the present invention, and the coating workability and the like of the heat-sealing agent of the present invention are improved. It is preferred that the adhesion or the heat and humidity resistance coexist.

The heat sealant of the present invention is obtained by, for example, a water dispersion of the urethane resin (A) obtained by the above method, an aqueous dispersion of the polyolefin resin (B), or a crosslinked with the heat sealant. The agent (C) can be produced by mixing. The crosslinking agent (C) may be premixed with the alkylated methylol melamine resin (c1) or the epoxy compound, or may be separately mixed with the aqueous dispersion of the urethane resin (A) or the The aqueous dispersion of the polyolefin resin (B) is mixed.

In addition to the above components, the heat sealant of the present invention obtained by the above method may contain other additives and the like as necessary.

As the additive, for example, an antioxidant, a light stabilizer, a plasticizer, a film-forming auxiliary agent, a flat agent, a foaming agent, a tackifier, a colorant, a flame retardant, or the like can be used without departing from the effects of the present invention. Other water-based resins, various fillers, and the like.

Moreover, as the additive, for example, a surfactant can be used from the viewpoint of further improving the dispersion stability of the heat sealant of the present invention. However, since the surfactant has a decrease in the adhesion or water resistance of the obtained coating film, the interface activity is 100 parts by mass based on the total of the urethane resin (A) and the polyolefin resin (B). The agent is preferably used in the range of 20 parts by mass or less, preferably not used as much as possible.

The heat sealant of the present invention is capable of forming a heat seal layer having superior adhesion to a substrate and superior moist heat resistance. In particular, since the heat sealant of the present invention has superior adhesion to any of the polar substrate (I) and the non-polar substrate (II), it can be applied to a polar substrate (I) and a non-polar substrate ( II) Adhesive for heat sealing. Specifically, the opposite side (face) can be formed with respect to the light-receiving surface constituting the solar cell, and can be suitably formed by using ethylene-vinyl acetate copolymer or polyvinylidene fluoride resin, polyvinyl fluoride resin, ethylene-ethylene. a non-polar substrate composed of an alcohol copolymer, a polypropylene resin, polyvinyl butyral, glass, or the like, and a back sheet layer (non-polar substrate) composed of polyethylene terephthalate or polypropylene Adhesive for heat sealing.

Examples of the substrate capable of forming the heat seal layer include various plastics or films thereof, metal, glass, paper, wood, and the like. Specifically, examples of the polar substrate include a polyethylene terephthalate substrate and the like. Further, examples of the non-polar substrate include ethylene-vinyl acetate copolymer or polyvinylidene fluoride resin, polyvinyl fluoride resin, ethylene-vinyl alcohol copolymer, polypropylene resin, and polyvinyl butyral. A substrate made of glass or the like.

On the surface of the substrate, surface treatment may also be performed in advance, specifically Preferably, corona treatment has been performed. According to the corona treatment, in the case where a reactive group such as a carbonyl group is formed on the surface of the substrate, a bond to the urea bond of the urethane resin (A) contained in the heat sealant of the present invention is formed. As a result, it is speculated that the adhesion can be further improved.

Further, the heat sealant of the present invention is obtained by placing another substrate on the surface of the resin layer which has been formed by being applied to the surface of the substrate on one side and dried to some extent, and is heated and can be used in accordance with The hydroxyl group formed by the crosslinking reaction reacts with the hydrolyzable alkylene group bonded to the epoxy compound, and is used for bonding the two substrates. If the surface of the substrate formed on the one side is dried and the surface of the formed resin layer is subjected to the heating, the resin can be preliminarily provided on the surface of the substrate laminated on one side because there is almost no adhesive feeling. Store in the state of the members of the layer.

On the other hand, when the substrate on the other side is placed on the surface of the heat seal layer and heated, the melting and crosslinking reaction of the heat seal layer can be performed to firmly adhere the two substrates. . Further, since the heat seal layer formed after the cross-linking reaction is also excellent in moist heat resistance, it is possible to prevent deterioration of the heat seal layer due to heat or water (moisture) or the like.

Examples of the method of applying the heat sealant of the present invention to the surface of the substrate include a spray method, a shower coating method, a flow coating method, a roll coating method, a brush coating method, and a dipping method.

In particular, in the case where the heat sealant or the like is applied to the surface of the plastic film such as polyethylene terephthalate film, the step of biaxially stretching the plastic substrate is carried out at about 200 ° C. Coating and drying the heat sealant on the surface of the film to cause a cross-linking reaction to form a heat seal layer, and then The in-line coating method of stretching the film in the transverse direction can be employed.

Further, when the heat sealant or the like is applied to the surface of a plastic film such as a polyethylene terephthalate film, the following off-coating method can be employed: the plastic film obtained by the biaxial stretching is temporarily The film is wound on a roll or the like, and then the plastic film is pulled out from the roll, and the heat sealant or the like is applied to the surface.

When the heat sealant or the like is applied to the surface of the plastic film according to the off-coating method, it is preferred to dry at a temperature of about 150 ° C or less in such a manner that the dimensional stability of the plastic film is not impaired. Wait.

According to the above method, a heat seal layer formed by crosslinking and curing the heat sealant can be formed on the surface of the substrate.

Further, as described above, by applying the heat sealant of the present invention to the surface of one side of the substrate, and fixing the heat seal layer formed by crosslinking and curing the heat sealant to the surface of the substrate, The substrate is placed on the surface of the heat seal layer, and then heated to a temperature of about 100 ° C to 160 ° C under reduced pressure or pressure to obtain a laminate in which the laminates are bonded.

The laminate also has excellent heat and humidity resistance, and can be used, for example, in the production of a solar cell module (solar power generation device) or in various applications in which the interior material of the automobile is fixed. In particular, it can be applied to an opposite side (face) with respect to the light-receiving surface constituting the solar cell, and can be suitably used from an ethylene-vinyl acetate copolymer or a polyvinylidene fluoride resin, a polyvinyl fluoride resin, an ethylene-vinyl alcohol copolymer, or a polypropylene. a non-polar substrate composed of a resin, polyvinyl butyral, glass, or the like, and a back sheet layer (non-polar substrate) composed of polyethylene terephthalate or polypropylene Sticky.

In general, the solar cell module is often provided for the purpose of preventing deterioration of the surface of the substrate which is formed of an ethylene-vinyl acetate copolymer or the like which constitutes the opposite side surface with respect to the light-receiving surface of the solar cell. There is a back sheet layer composed of polyethylene terephthalate or polypropylene. For example, the heat seal layer formed by curing the heat sealant of the present invention is provided on the surface of the substrate composed of the ethylene-vinyl acetate copolymer constituting the opposite side with respect to the light receiving surface constituting the solar cell. Then, it can be manufactured by laminating a back sheet layer made of polyethylene terephthalate or polypropylene on the heat seal layer.

More specifically, in the surface of the sheet which can be formed of polyethylene terephthalate or polypropylene of the back sheet layer, a laminate sheet having a heat seal layer formed by curing the heat sealant is prepared, and is relatively On the surface of the substrate composed of the ethylene-vinyl acetate copolymer on the opposite side of the light-receiving side of the solar cell, by heat-sealing the laminated sheet and the surface of the substrate composed of the ethylene-vinyl acetate copolymer The contact can be placed and heated to laminate the layers.

The solar cell module obtained by such a method has superior heat and humidity resistance and durability even when used outdoors for a long period of time.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples and comparative examples.

[Modulation Example 1]

With mixer, reflux cooling tube, thermometer and nitrogen injection tube In a 4-necked flask, 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000), 79.4 parts by mass of 2,2'-dimethylolpropionic acid, and ethyl acetate were added in a nitrogen stream. 884.3 parts by mass, after uniformly mixing, 247.2 parts by mass of toluene diisocyanate was added, followed by 0.1 part by mass of dibutyltin dilaurate, and reacted at 80 ° C for about 4 hours to obtain a carbamate having an isocyanate group at the molecular terminal. Ethyl ester prepolymer (mass ratio of isocyanate group to urethane prepolymer (isocyanate group content): 2.1% by mass) in ethyl acetate solution.

Next, the ethyl acetate solution of the urethane prepolymer obtained by the above method was cooled to 40 ° C, and 65.9 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane prepolymer. 2849.1 parts by mass of ion-exchanged water was added, followed by addition of 24.6 parts by mass of 80% by mass of hydrazine hydrate (one hydrate of hydrazine, 80% by mass based on the whole).

After completion of the reaction, the ethyl acetate was distilled under reduced pressure, and ion-exchanged water was added so that the nonvolatile content was 35% by mass to obtain a composition (I).

[Modulation Example 2]

In a 4-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer, and a nitrogen injection tube, 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000) was added in a nitrogen stream, 2, 2'- 79.4 parts by mass of dimethylolpropionic acid and 668.2 parts by mass of ethyl acetate, after uniformly mixing, 247.2 parts by mass of toluene diisocyanate was added, followed by 0.1 part by mass of dibutyltin dilaurate, and the reaction was carried out at 80 ° C for about 4 parts. A urethane prepolymer having an isocyanate group at the molecular end (the mass ratio of the isocyanate group to the urethane prepolymer (isocyanate group content) is obtained in an hour: 2.1% by mass of ethyl acetate solution.

Next, the ethyl acetate solution of the urethane prepolymer obtained by the above method was cooled to 40 ° C, and 65.4 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane prepolymer. 3174.1 parts by mass of ion-exchanged water was added, followed by addition of 136.9 parts by mass of diammonium adipate to cause a reaction.

After completion of the reaction, the ethyl acetate was distilled under reduced pressure, and ion-exchanged water was added so that the nonvolatile content was 35% by mass to obtain a composition (II).

[Modulation Example 3]

In a reactor equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer, 1000 parts by mass of Polystar VS-1236 (available as a water dispersion of a maleic anhydride-modified polyolefin manufactured by Starlight PMC Co., Ltd.) was introduced while introducing nitrogen gas. The weight average molecular weight of 70,000) was melted by stirring at 80 ° C for 3 hours, followed by cooling to 50 ° C, and after neutralizing 180 parts by mass of triethylamine, 2153 parts by mass of water was added thereto to dissolve the water, thereby obtaining The composition (III) having a nonvolatile content of 30% by mass.

[Modulation Example 4]

In a 4-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer, and a nitrogen injection tube, 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000) was added in a nitrogen stream, 2, 2'- 79.4 parts by mass of dimethylolpropionic acid and 668.2 parts by mass of ethyl acetate, after uniformly mixing, 247.2 parts by mass of toluene diisocyanate was added, followed by 0.1 part by mass of dibutyltin dilaurate, and the reaction was carried out at 80 ° C for about 4 parts. A urethane prepolymer having an isocyanate group at the molecular end (isocyanate) is obtained in an hour A ratio of the mass of the urethane prepolymer (isocyanate group content): 2.1% by mass of an ethyl acetate solution.

Next, the ethyl acetate solution of the urethane prepolymer obtained by the above method was cooled to 40 ° C, and 65.9 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane prepolymer. 3111.0 parts by mass of ion-exchanged water was added, followed by addition of 70.8 parts by mass of carbodiimide to cause a reaction.

After completion of the reaction, the ethyl acetate was distilled under reduced pressure, and ion-exchanged water was added so that the nonvolatile content was 35% by mass to obtain the composition (IV).

[Modulation Example 5]

In a 4-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer, and a nitrogen injection tube, 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000) was added in a nitrogen stream, 2, 2'- 79.4 parts by mass of dimethylolpropionic acid and 884.3 parts by mass of ethyl acetate, after uniformly mixing, 247.2 parts by mass of toluene diisocyanate was added, followed by 0.1 part by mass of dibutyltin dilaurate, and the reaction was carried out at 80 ° C for about 4 parts. An ethyl acetate solution of a urethane prepolymer having an isocyanate group at the molecular terminal (mass ratio of isocyanate group to the urethane prepolymer (isocyanate group content): 2.1% by mass) was obtained in an hour.

Next, the ethyl acetate solution of the urethane prepolymer obtained by the above method was cooled to 40 ° C, and 65.9 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane prepolymer. 2849.1 parts by mass of ion-exchanged water was added, and then 80.5% by mass of hydrazine hydrate (one hydrate of hydrazine, 80% by mass based on the whole) was added to 18.5 parts by mass.

After completion of the reaction, the ethyl acetate was distilled under reduced pressure, and ion-exchanged water was added so that the nonvolatile content was 35% by mass to obtain a composition (V).

[Modulation Example 6]

830 parts by mass of terephthalic acid, 830 parts by mass of isophthalic acid, 374 parts by mass of ethylene glycol, 604 parts by mass of neopentyl glycol, and oxidized in a reactor equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer 0.5 parts by mass of dibutyltin, after esterification at 180 to 230 ° C for 5 hours, the acid value was made less than 1, and the polymerization was carried out at 260 ° C for 6 hours to obtain a polyester polyol having an acid value of 0.2 and a hydroxyl group of 74.5 (a1). ').

1000 parts by mass of the polyester polyol (a1') was dehydrated under reduced pressure at 100 ° C, and then cooled to 80 ° C, and 690 parts by mass of methyl ethyl ketone was added thereto, and the mixture was sufficiently stirred and dissolved to add 2, 2'. 77 parts by mass of dimethylolpropionic acid, 209 parts by mass of hexamethylene diisocyanate was further added, and the mixture was reacted at 75 ° C for 8 hours.

After confirming that the mass ratio of the unreacted isocyanate group remaining in the reaction mixture is 0.1% by mass or less, after cooling to 50° C., 58 parts by mass of triethylamine and 5100 parts by mass of water are added, and under reduced pressure, at 40°C The methyl ethyl ketone was removed at a temperature of 60 ° C, and water was added thereto to adjust the concentration to obtain a composition (VI) in which the nonaqueous content of the aqueous urethane resin dispersed in water was 20% by mass.

[Example 1]

100 parts by mass of the composition (I) obtained in Preparation Example 1 and 78 parts by mass of the composition (III) obtained in Preparation Example 3 were mixed. Next, add Reckamine M-3 (Trimethoxymethylol by DIC Corporation) 5 parts by mass of a melamine resin and a nonvolatile component, and 4 parts by mass of Denacol EX-321 (manufactured by Nagase Chemtex Co., Ltd., trimethylolpropane triepoxypropyl ether, 100% by mass of a nonvolatile matter), And a mixture of 3 parts by mass of diammonium adipate (molecular weight: 174.2) and water to obtain a heat-sealing agent (X-1) composed of an aqueous resin composition (X-1) having a nonvolatile content of 20% by mass. ).

[Embodiment 2]

An aqueous resin composition was obtained by the same method as in Example 1 except that 100 parts by mass of the composition (II) obtained in Preparation Example 2 was used instead of the composition (I) of 100 parts by mass obtained in Preparation Example 1 ( X-2) A heat sealant (X-2).

[Example 3]

In the same manner as in Example 1, except that the amount of Beckamine M-3 (trimethoxymethylol type melamine resin manufactured by DIC Corporation and 80% by mass of nonvolatile matter) was changed from 5 parts by mass to 23 parts by mass. The heat sealant (X-3) composed of the aqueous resin composition (X-3) was obtained by the method.

[Example 4]

In addition to the use of Denacol EX-321 (manufactured by Nagase Chemtex Co., Ltd., trimethylolpropane triepoxypropyl ether, 100% by mass of nonvolatile matter), the amount of use is changed from 4 parts by mass to 42 parts by mass. In the same manner as in Example 1, a heat sealant (X-4) composed of an aqueous resin composition (X-4) was obtained.

[Example 5]

In addition to Denacol EX-321 (manufactured by Nagase Chemtex Co., Ltd., trimethylolpropane triepoxypropyl ether, non-volatile content 100 mass A heat sealant (X-5) composed of an aqueous resin composition (X-5) was obtained in the same manner as in Example 1 except that the amount of the compound was changed from 4 parts by mass to 1 part by mass.

[Embodiment 6]

In addition, the amount of the composition (III) described in Preparation Example 3 was changed from 78 parts by mass to 175 parts by mass, and Beckamine M-3 (a trimethoxymethylol type melamine resin manufactured by DIC Corporation, a nonvolatile matter 80) was used. The amount of the mass%) was changed from 5 parts by mass to 7 parts by mass, and the amount of Denacol EX-321 (manufactured by Nagase Chemtex Co., Ltd., trimethylolpropane triepoxypropyl ether, 100% by mass of nonvolatile matter) was used. The aqueous resin composition (X-6) was obtained in the same manner as in Example 1 except that the amount was changed from 4 parts by mass to 8 parts by mass and diammonium adipate (molecular weight: 174.2) was 4 parts by mass. Heat sealant (X-6).

[Embodiment 7]

In addition to 5 parts by mass of Beckamine J-101 (hexamethoxymethylol melamine resin manufactured by DIC Co., Ltd., 80% by mass of nonvolatile matter), Beckamine M-3 (trimethoxyl of DIC Co., Ltd.) was used. A heat sealant (X-7) composed of the aqueous resin composition (X-7) was obtained in the same manner as in Example 1 except that the methyl melamine resin and the nonvolatile content were 80% by mass.

[Embodiment 8]

An aqueous resin composition (X) was obtained by the same method as in Example 1 except that 100 parts by mass of the composition (IV) obtained in Preparation Example 4 was used instead of 100 parts by mass of the composition (I) obtained in Preparation Example 1. -8) The heat sealant (X-8).

[Embodiment 9]

An aqueous resin composition (X) was obtained by the same method as in Example 1 except that 100 parts by mass of the composition (V) obtained in Preparation Example 5 was used instead of 100 parts by mass of the composition (I) obtained in Preparation Example 1. -9) The heat sealant (X-9).

[Embodiment 10]

An aqueous resin composition (X) was obtained by the same method as in Example 1 except that 100 parts by mass of the composition (VI) obtained in Preparation Example 6 was used instead of 100 parts by mass of the composition (I) obtained in Preparation Example 1. -10) A heat sealant (X-10).

[Comparative Example 1]

100 parts by mass of the composition (I) obtained in Preparation Example 1 and 78 parts by mass of the composition (III) obtained in Preparation Example 3 were stirred and water was added to obtain an aqueous resin composition containing 20% by mass of the nonvolatile component. (X'-1) A heat sealant (X'-1).

[Comparative Example 2]

100 parts by mass of the composition (III) obtained in Preparation Example 3, and 2 parts by mass of Beckamine M-3 (trimethoxymethylol type melamine resin manufactured by DIC Corporation, 80% by mass of nonvolatile matter), and 4 parts by mass of Denacol EX-321 (manufactured by Nagase Chemtex Co., Ltd., trimethylolpropane triepoxypropyl ether, 100% by mass of nonvolatile matter), and stirred, water was added to obtain 20% by mass of nonvolatile matter A heat sealant (X'-2) composed of a resin composition (X'-2).

[Comparative Example 3]

In addition to using Chemitite PZ-33 (Japan Catalyst Co., Ltd. 5 parts by mass of Beckamine M-3 (trimethoxymethylol type melamine resin manufactured by DIC Co., Ltd., 80% by mass of nonvolatile matter) and Denacol EX were replaced by Beckamine M-3 (100% by mass of a non-volatile component) An aqueous resin composition was obtained by the same method as in Example 1 except that -321 (manufactured by Nagase Chemtex Co., Ltd., trimethylolpropane triepoxypropyl ether, 100% by mass of nonvolatile matter) was used in an amount of 4 parts by mass. (X'-3) A heat sealant (X'-3).

[Comparative Example 4]

An aqueous resin composition (X) was obtained by the same method as in Comparative Example 3, except that 100 parts by mass of the composition (VI) obtained in Preparation Example 6 was used instead of 100 parts by mass of the composition (I) obtained in Preparation Example 1. '-4) A heat sealant (X'-4).

[Method for evaluating the adhesion of polar substrates and non-polar substrates]

The heat sealant obtained in the examples and the comparative examples was applied to the surface of the polyethylene terephthalate film of the polar substrate to a dry film thickness of 5 μm, and dried at 150 ° C for 5 minutes. Further, a laminate provided with a resin hardened layer (heat seal layer) crosslinked to the film surface was obtained.

A film made of ethylene-vinyl acetate of a non-polar substrate (5 cm in length × 1 cm in width) is placed on the surface of the resin-hardened layer (heat-sealing layer) of the laminate, and then a vacuum pressure-adhering device is used. The laminate was pressure-bonded at 150 ° C for 15 minutes to obtain a laminate in which the resin hardened layer (heat seal layer) was interposed and the polyethylene terephthalate film and the polyolefin film were adhered.

[Test method for closeness]

Subsequent laminar adhesion using the above method The tensile tester (autoclave manufactured by Shimadzu Corporation) was evaluated by a T-peel test (1000 N unit). The adhesion is evaluated based on the adhesion between the heat seal layer and the film composed of the ethylene-vinyl acetate.

The peel strength measured by the above method was about 30 N/cm or more, and it was evaluated as having excellent adhesion; those of 35 N/cm or more were evaluated as having particularly excellent adhesion.

[Evaluation of heat and humidity resistance]

The laminate obtained above was allowed to stand in a constant temperature and humidity machine set to 120 ° C × 100% RH for 72 hours to carry out a damp heat test. The adhesion of the laminate after standing was measured by the same method as described above.

The peel strength measured by the above method was about 25 N/cm or more, and it was evaluated as having excellent adhesion; those of 35 N/cm or more were evaluated as having particularly excellent adhesion.

[Observation of the peeling interface (after the damp heat test)]

The laminate obtained above was allowed to stand in a constant temperature and humidity machine set to 121 ° C × 100% RH for 72 hours to carry out a damp heat test.

The peeling interface of the laminate after the damp heat test was visually observed. As a result, the film composed of the ethylene-vinyl acetate itself was evaluated as "A" by the fracture of the aggregation failure; the fracture of the heat sealant layer due to the aggregation failure was evaluated as "B"; the film and the layer were not The fracture is evaluated as "C" when the interface between the film composed of the ethylene-vinyl acetate and the heat sealant layer is peeled off; the film and the layer are not broken, and the polyethylene terephthalate film is The peeling of the interface of the heat sealant layer was evaluated as "D". Appraised as A to C, practically usable, especially evaluated as A to B can be applied to situations where a higher level of characteristics is sought.

The content of the alkylated methylol melamine resin (c1) [% by mass] in Tables 1 to 3 indicates the mass of the combined quality of the alkylated methylol melamine resin to the urethane resin and the polyolefin resin. proportion.

In addition, "M-3" in the table indicates Beckamine M-3 (trimethoxymethylol type melamine resin manufactured by DIC Corporation, 80% by mass of nonvolatile matter), and "EX-321" indicates Denacol EX. -321 (manufactured by Nagase Chemtex Co., Ltd., trimethylolpropane triepoxypropyl ether, 100% by mass of nonvolatile matter), and "J-101" means Beckamine J-101 (hexamethoxy produced by DIC Corporation) "Hydroxymethyl melamine resin, 80% by mass of a nonvolatile component", and "PZ-33" is a Chemitite PZ-33 (manufactured by Nippon Shokubai Co., Ltd., polyfunctional anthracene cyclopropane, 100% by mass of a nonvolatile component).

Claims (9)

A heat sealant characterized by containing a urethane resin (A), a polyolefin resin (B), and containing a melamine compound, an epoxy compound, More than one crosslinking agent (C) of the group consisting of an oxazoline compound, a carbodiimide compound and an isocyanate compound, a compound (D) having a molecular weight of 20 to 3,000 having a primary or tertiary group, and an aqueous medium (E). The heat sealant of claim 1, wherein the compound (D) is hydrazine, dicarboxylic acid dihydrazide or homodiamine urea. The heat sealant according to claim 1, wherein the crosslinking agent (C) contains an alkylated methylol melamine resin (c1) as a melamine compound and an epoxy compound (c2), and the urethane is used. Any one or both of the ester resin (A) and the polyolefin resin (B) have a functional group [X] reactive with an epoxy group. The heat sealant of claim 3, wherein the alkylated methylol melamine resin (c1) is relative to the total mass of the urethane resin (A) and the polyolefin resin (B) It is contained in the range of 5 mass% to 50 mass%, and the mass of the epoxy group bonded to the epoxy compound (c2) is the mass of the urethane resin (A) and the polyolefin resin (B). The ratio of the total mass of the one or two bonded functional groups [X] [the mass of the epoxy group / the total mass of the functional group [X]] is from 5/1 to 1/5. A laminate provided by applying a heat sealant according to any one of claims 1 to 4 to a surface of a polar substrate (I) and drying the heat seal layer, and by The non-polar substrate (II) is placed on the surface of the heat-sealing layer, followed by heating at 80 ° C to 180 ° C. The laminate of claim 5, wherein the polar substrate (I) is a polyethylene terephthalate substrate, a polypropylene substrate, a polycarbonate substrate or a polyamide substrate, and the non- The polar substrate (II) is a substrate composed of an ethylene-vinyl acetate copolymer. A method for producing a laminate, which is characterized in that the urethane resin is applied by applying a heat sealant according to any one of claims 1 to 4 to a surface of a polar substrate (I) and drying ( A) reacting with the functional group [X] bonded to either or both of the polyolefin resin (B) and the epoxy group bonded to the epoxy compound (c2), and also by a self-crosslinking reaction of the alkylated methylol melamine resin (c1) and/or a hydroxyl group formed by the reaction of the functional group [X] with the epoxy compound (c2) and the alkylated methylol melamine resin ( The reaction of c1) is carried out to provide a heat seal layer, and then the non-polar substrate (II) is placed on the surface of the heat seal layer, and then the polar substrate (I) is adhered by heating at 80 ° C to 180 ° C. With non-polar substrate (II). A solar cell module characterized in that it is used on the surface of a substrate composed of an ethylene-vinyl acetate copolymer on the opposite side to a light receiving surface constituting the solar cell, and is used in any one of claims 1 to 4 of the patent application scope. The heat seal layer formed by the heat sealant has a polyethylene terephthalate substrate, a polypropylene substrate, a polycarbonate substrate or a polyamide substrate on the heat seal layer. Back layer. A method for manufacturing a solar cell module, characterized in that a surface of a sheet composed of a polyethylene terephthalate substrate, a polypropylene substrate, a polycarbonate substrate or a polyamide substrate is formed in relation to Forming a light-receiving surface of a solar cell On the surface of the substrate on the opposite side of the ethylene-vinyl acetate copolymer, the heat-sealing layer of the laminated sheet is placed and heated in contact with the surface of the substrate made of the ethylene-vinyl acetate copolymer. A laminated sheet of a heat seal layer formed by using a heat sealant according to any one of claims 1 to 4.