KR101636637B1 - Heat sealing agent, laminate body using same, and solar cell module - Google Patents

Abstract

A problem to be solved by the present invention is to provide a heat sealant capable of forming a heat seal layer having a high humidity and heat resistance at a level that does not cause a decrease in adhesion due to the influence of heat or water, will be. The present invention relates to a urethane resin composition containing a urethane resin (A), a polyolefin resin (B), a crosslinking agent (C) and an aqueous medium (D), wherein the urethane resin (A) is a urethane resin having an isocyanate group, , A compound having a hydrazide group and a hydrazine, wherein the crosslinking agent (C) contains an alkylated methylol melamine resin (c1) and an epoxy compound (c2), and the urethane resin ( A and either or both of the polyolefin resin (B) has a functional group which reacts with an epoxy group.

Description

{HEAT SEALING AGENT, LAMINATE BODY USING SAME, AND SOLAR CELL MODULE}

The present invention relates to a heat sealant usable for bonding various members, particularly polar members and non-polar members.

BACKGROUND ART As members used for manufacturing automobile parts, home electric appliances, solar power generation devices and the like, members including ethylene-vinyl acetate resin and polyolefin resin excellent in weatherability and water resistance, excellent in moldability and recyclability, .

The ethylene-vinyl acetate resin is generally liable to be deteriorated by being exposed to heat or water (moisture), and is insufficient in terms of heat and humidity resistance. For this reason, in the case where the ethylene / vinyl acetate resin base material is provided with a heat and humidity resistant property at a level at which the degradation can be suppressed by joining glass or a polyethylene terephthalate base material to a member including the ethylene-vinyl acetate resin, There are many.

However, since a substrate including an ethylene-vinyl acetate resin is generally a substrate having a low surface polarity, even if an adhesive is used to bond the substrate containing the ethylene-vinyl acetate resin to the glass or the like, The adhesive layer may deteriorate due to the influence of heat or water even if it can be easily peeled or temporarily bonded at the interface of the adhesive layer with the surface of the substrate containing the ethylene-vinyl acetate resin, there was.

On the other hand, by adjusting the composition of the adhesive, it is possible to produce an adhesive excellent in adhesion to a non-polar substrate such as the ethylene-vinyl acetate resin. However, the adhesive excellent in adhesion to the non-polar substrate is not sufficient in terms of adhesion to the polar substrate such as the glass or the polyethylene terephthalate substrate, so that the adhesion between the polar substrate and the adhesive layer is lowered, There was a case where peeling occurred.

Thus, it has been difficult to find an adhesive having excellent adhesion to any of the non-polar substrate and the polar substrate.

As adhesives having excellent adhesiveness, for example, adhesives including an aqueous dispersion containing an acid-modified polyolefin resin, a polyurethane resin, a fatty acid amide and a terpene-based tackifier at a specified ratio in an aqueous medium are known. It is known that the adhesion to a thermoplastic resin substrate is excellent (see, for example, Patent Document 1).

However, since the adhesive does not have excellent adhesion to both the non-polar substrate and the polar substrate, there has been occasionally peeled off at an interface between one of the substrates and the adhesive layer with time.

Further, since the adhesive is easily deteriorated by exposure to heat or water (moisture), it causes deterioration or peeling of the adhesive layer with time due to the influence of heat or water, and as a result, .

However, in the case of joining substrates using the above-described adhesive, it is usual that an adhesive is applied to the surface of either one of the substrates immediately before joining, and subsequently, The other substrate is laminated on the surface of the adhesive layer and cured to bond them together in many cases.

However, in such a method, it is necessary to perform an operation such as coating an adhesive agent on a work site for joining the substrate or removing the solvent contained in the adhesive agent. Therefore, the production efficiency of the composite member is remarkably lowered There was a case.

Japanese Patent Application Laid-Open No. 2009-235289

A problem to be solved by the present invention is to provide a heat sealable layer having excellent adhesion to polar substrates and non-polar substrates and having a level of resistance to humidity and humidity which does not cause a decrease in adhesiveness due to the influence of heat or water And a heat seal agent.

Another problem to be solved by the present invention is to provide a polarizing plate which has excellent adhesion to polar substrates and non-polar substrates and which has a resistance to humidity and humidity at a level that does not cause deterioration or deterioration of adhesiveness due to the influence of heat or water A heat seal layer can be formed, and the heat sealant is previously coated on the surface of one substrate and dried to form a crosslinked heat seal layer, and then the other substrate is placed on the heat seal layer and heated And a heat seal agent capable of bonding these substrates.

The present inventors have conducted research based on a resin composition comprising a combination of a urethane resin and a polyolefin resin. As a result, it has been found that by using a combination of a urethane resin having a specific terminal structure and a polyolefin resin and a specific crosslinking agent in combination, Can be solved.

That is, the present invention is a heat sealant containing a urethane resin (A), a polyolefin resin (B), a crosslinking agent (C) and an aqueous medium (D), wherein the urethane resin (A) comprises an isocyanate group- (C1) is obtained by reacting an alkylated methylol melamine resin (c1) with an epoxy compound (c2), wherein the crosslinking agent (C) is obtained by reacting at least one member selected from the group consisting of a compound having a primary amino group, a compound having a hydrazide group and a hydrazine. And either or both of the urethane resin (A) and the polyolefin resin (B) has a functional group [X] reacting with an epoxy group.

The heat sealant of the present invention has excellent adhesiveness not only to ethylene vinyl acetate resin and polyolefin resin widely used in industry but also to substrates including polyethylene terephthalate and the like, They can be used for covering the surfaces of these substrates.

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

The heat sealant of the present invention is a heat sealant containing a urethane resin (A), a polyolefin resin (B), a crosslinking agent (C) and an aqueous medium (D), wherein the urethane resin (A) comprises an isocyanate group- (C1) and the epoxy compound (c2) are obtained by reacting the alkylated methylol melamine resin (c1) with at least one member selected from the group consisting of a compound having a primary amino group, a compound having a hydrazide group and a hydrazine. , And either or both of the urethane resin (A) and the polyolefin resin (B) has a functional group [X] capable of reacting with an epoxy group.

The alkylated methylol melamine resin (c1) forms a crosslinked structure by self-crosslinking reaction. When a functional group such as a hydroxyl group is generated when the functional group [X] of the urethane resin (A) and the polyolefin resin (B) react with the epoxy compound (c2), the hydroxyl group and the alkylated methylol The melamine resin (c1) reacts to form a crosslinked structure.

Here, the problem of the present invention can not be solved only by using the alkylated methylol melamine resin (c1) as the crosslinking agent (C). Even when the alkylated methylol melamine resin (c1) is used alone as the crosslinking agent (C), it may be difficult to achieve both excellent moisture resistance and excellent adhesion to various substrates.

In the present invention, as the crosslinking agent (C), the alkylated methylol melamine resin (c1) and the epoxy compound (c2) are used in combination.

The epoxy compound (c2) reacts with the functional group [X] contained in either or both of the urethane resin (A) and the polyolefin resin (B) to form a crosslinked structure. Thereby, it is possible to obtain a heat sealant having excellent moisture resistance and excellent adhesion to various substrates.

As the urethane resin (A) and the polyolefin resin (B) used in combination with the crosslinking agent (C), a functional group [X] capable of reacting with the epoxy group contained in the crosslinking agent (C) Is used. Specific examples of the functional group of the epoxy compound (c2) include a hydrolyzable silyl group such as an alkoxysilyl group and a silanol group, and an epoxy group.

Examples of the functional group [X] include a carboxyl group, a hydroxyl group, and an amino group. When a urethane resin and a polyolefin resin having a hydrophilic group such as an anionic group and a cationic group are used for stably presenting the urethane resin (A) and the polyolefin resin (B) in the aqueous medium (D) The carboxyl group as a hydrophilic group or a carboxylate group formed by neutralizing it with a basic compound acts as the functional group [X] during the crosslinking reaction and can react with a part of the crosslinking agent (C). Accordingly, as the functional group [X], there can be used a cationic group such as an amino group neutralized by an anionic group such as a carboxylate group or a sulfonate group neutralized by a basic compound or an acidic compound, which is capable of functioning as a hydrophilic group have. Among the above-mentioned functional groups [X], those having a carboxyl group or carboxyl group are preferred.

Particularly, when a carboxyl group is used as the functional group [X], the urethane resin (A) preferably has an acid value of 5 to 70, more preferably an acid value of 5 to 50 , And an acid value of 5 to 35 is more preferable for further improving the adhesion to various substrates. 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.

The urethane resin (A) and the polyolefin resin (B) are preferably dispersed or dissolved independently in the aqueous medium (D), but a part of them may be combined to form resin particles, Or may form composite resin particles.

Among them, it is preferable that the urethane resin (A) and the polyolefin resin (B) can be independently dispersed in the aqueous medium (D) by forming resin particles.

The resin particles preferably have an average particle diameter in the range of approximately 10 nm to 500 nm in order to enhance the smoothness of the coating film to be formed. Here, the average particle diameter refers to an average particle diameter on a volume basis measured by a dynamic light scattering method.

The ratio by mass 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 5/5, and further more preferably in the range of 8/2 to 5/5 in terms of achieving both excellent wet heat resistance and excellent adhesion to various substrates.

It is preferable that the urethane resin (A) and the polyolefin resin (B) are contained in the range of 5% by mass to 70% by mass with respect to the total amount of the heat sealant of the present invention, This is preferable in terms of maintaining workability.

The urethane resin (A) and the polyolefin resin (B) may have a hydrophilic group from the viewpoint of imparting good dispersion stability in the aqueous medium (D). As the hydrophilic group, for example, a polyoxyethylene structure as 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 carboxylate group, a sulfonic acid group, a sulfonate group and the like can be used. Among them, a carboxylate group or a sulfonate group formed by neutralization of a part or the whole with a basic compound is used (A) and polyolefin resin (B) having good water dispersibility.

As the cationic group, for example, a tertiary amino group, a functional group neutralized by using an acidic compound or a quaternizing agent can be used.

Examples of the nonionic group include polyoxyalkylene groups such as polyoxyethylene group, polyoxypropylene group, polyoxybutylene group, poly (oxyethylene-oxypropylene) group and polyoxyethylene-polyoxypropylene group Can be used.

The urethane resin (A) is used for obtaining a heat sealer having the functional group [X] and capable of forming a heat seal layer having both excellent moisture resistance and excellent adhesion to various substrates.

As the urethane resin (A), it is preferable that the isocyanate group of the urethane resin, the hydrazide group having at least one member selected from the group consisting of a compound having a primary amino group, a compound having a hydrazide group, and hydrazine, a primary amino group, A compound having a urea bond formed by reacting a nitrogen atom is used. As a result, the adhesion to various substrates can be remarkably improved. In particular, it exhibits excellent adhesion to the surface of a substrate such as a polar substrate (E) subjected to corona treatment or the like. This is presumably because the carbonyl group is formed on the substrate surface by the corona treatment or the like, and the carbonyl group forms a bond with the nitrogen atom forming the urea bond.

It is preferable that the urea bond is present in the range of 50 mmol / kg to 2,000 mmol / kg with respect to the entire urethane resin (A) in order to further improve adhesion to the substrate.

As the urethane resin (A), those having a weight average molecular weight in the range of 5,000 to 200,000 can be used for forming the heat seal layer having excellent adhesion and durability to the polar base material (E) and the non-polar base material (F) More preferably in the range of 50,000 to 20,000.

Examples of the urethane resin (A) include a urethane resin having an isocyanate group obtained by reacting a polyol (a1) with a polyisocyanate (a2), a compound comprising a primary amino group, a compound having a hydrazide group, , And at least one compound selected from the group consisting of a compound represented by formula

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

Among them, it is preferable to use a polyether polyol because the adhesion to the non-polar substrate (F) can be further improved.

As the polyether polyol which can be used for the polyol (a1), for example, one obtained by subjecting one or more compounds having two or more active hydrogen atoms as an initiator to addition polymerization of an alkylene oxide can be used.

Examples of the initiator include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, bisphenol A, glycerin, Olethane, trimethylolpropane and the like can be used.

As the alkylene oxide, for example, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran and the like can be used.

As the polyether polyol usable in the polyol (a1), specifically, polyoxytetramethylene glycol formed by ring-opening of tetrahydrofuran is preferably used.

As the polyether polyol, it is preferable to use a polyether polyol having a number average molecular weight of 500 to 3,000 in order to further improve the adhesion to the polar substrate (E) and the non-polar substrate (F).

The polyether polyol is preferably used in an amount of 50% by mass to 99.7% by mass, more preferably 50% by mass to 90% by mass, based on the entire polyol (a1) used in producing the urethane resin (A) Is more preferable.

Examples of the polyester polyol usable in the polyol (a1) include a polyester obtained by esterifying a low molecular weight polyol and a polycarboxylic acid, a polyester obtained by ring-opening polymerization reaction of a cyclic ester compound such as? -Caprolactone Polyester, copolyester of these, and the like can be used.

Examples of the low molecular weight polyol include polyols having a molecular weight of about 50 to 300, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, , Aliphatic polyols such as cyclohexanedimethanol and the like, polyols having an aliphatic cyclic structure such as cyclohexanedimethanol, bisphenol compounds such as bisphenol A and bisphenol F, and alkylene oxide adducts thereof.

Examples of the polycarboxylic acid that can be used in the production of the polyester polyol include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, Aromatic polycarboxylic acids such as naphthalene dicarboxylic acid, and anhydrides and esters thereof.

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

As the polycarbonate polyol usable for the polyol (a1), for example, those obtained by reacting a carbonic ester with a polyol, and those obtained by reacting phosgene and bisphenol A can be used.

As the carbonic ester, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used.

Examples of the polyol which reacts with the carbonic ester include ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, - a relatively low molecular weight diol having a molecular weight of 50 to 2,000 such as pentane diol, 1,4-cyclohexane diol, 1,6-hexane diol and cyclohexane dimethanol, polyethylene glycol, polypropylene glycol, polyhexamethylene adipate, etc. Can be used.

The polycarbonate polyol having a number average molecular weight in the range of 500 to 4,000 is preferably used as the polycarbonate polyol in a non-polar base material (F) containing ethylene-vinyl acetate resin, polypropylene and the like It is preferable for imparting adhesion to the substrate.

As the polyolefin polyol usable for the polyol (a1), for example, polyethylene polyol, polypropylene polyol, polyisobutene polyol, hydrogenated (hydrogenated) polybutadiene polyol, hydrogenated (hydrogenated) polyisoprene polyol can be used have.

As the polyol (a1), a polyol having a hydrophilic group may be used in combination with the polyol (a1), in addition to the above-mentioned one, from the viewpoint of imparting good water dispersion stability to the urethane resin (A).

As the polyol having a hydrophilic group, for example, a polyol having an anionic group other than the above-mentioned polyol, a polyol having a cationic group and a polyol having a nonionic group can be used. Among them, it is preferable to use a polyol having an anionic group or a polyol having a cationic group, and it is more preferable to use a polyol having an anionic group.

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-dimethylolvaleric acid and the like can be used. Among them, 2,2- Is preferably used. A polyester polyol having a carboxyl group obtained by reacting a polyol having a carboxyl group with various polycarboxylic acids may also be used.

Examples of the polyol having a sulfonic acid group include dicarboxylic acids such as 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid and 5 [4-sulfophenoxy] isophthalic acid, A polyester polyol obtained by reacting the low molecular weight polyol exemplified as usable for the production of the polyester polyol having a hydroxyl group can be used.

The polyol having a carboxyl group or the polyol having a sulfonic acid group is preferably used in the range of 10 to 70, more preferably 10 to 50, 35 < / RTI > In the present invention, the acid value is a theoretical value calculated on the basis of an amount of a compound having an acid group such as a polyol having a carboxyl group used for producing the urethane resin (A).

The above anionic groups are preferably neutralized by a basic compound in part or all of them in order to exhibit good water dispersibility.

Examples of the basic compound include organic amines having a boiling point of 200 ° C or higher such as ammonia, triethylamine, morpholine, monoethanolamine and diethylethanolamine, metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide have. The basic compound is preferably used in the range of from basic compound / anionic group = 0.5 to 3 (molar ratio), preferably 0.9 to 2 (molar ratio), from the viewpoint of improving the water dispersion stability of the obtained heat sealant Is more preferable.

As the polyol having a cationic group, for example, a polyol having a tertiary amino group can be used. Specifically, N-methyl-diethanolamine, a compound having two epoxides in one molecule and a secondary amine are reacted And the like can be used.

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, adipic acid and the like.

The tertiary amino group as the cationic group is preferably quaternized with a part or all of the tertiary amino group as the cationic group. As the quaternizing agent, for example, dimethylsulfuric acid, diethylsulfuric acid, methylchloride, ethylchloride and the like can be used, and it is preferable to use dimethylsulfuric acid.

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

The polyol having a hydrophilic group is preferably used in an amount of 0.3% by mass to 10% by mass relative to the total amount of the polyol (a1) used for producing the urethane resin (A).

As the polyol (a1), other polyols may be used, if necessary, in addition to the polyols described above.

Examples of the other polyols include ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, , 1,4-cyclohexanediol, 1,6-hexanediol, cyclohexanedimethanol, and the like can be used.

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.

Examples of the polyisocyanate (a2) to be reacted with the polyol (a1) include 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, Aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, xylene diisocyanate and tetramethyl xylylene diisocyanate, aromatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, and tetramethyl xylylene diisocyanate, aromatic polyisocyanates such as diisobutylene diisocyanate, A polyisocyanate having an aliphatic cyclic structure such as cyclohexane diisocyanate, dicyclohexylmethane diisocyanate and isophorone diisocyanate can be used.

The urethane resin (A) can be obtained by, for example, reacting the polyol (a1) with the polyisocyanate (a2) under a solventless condition or in the presence of an organic solvent to prepare an urethane resin having an isocyanate group, In the case where a hydrophilic group is present in the resin, a part or all of the above hydrophilic groups are neutralized if necessary in the aqueous medium (D) to form a compound having a primary amino group, a hydrazide group and hydrazine , And reacting the isocyanate group of the urethane resin with the isocyanate group of the urethane resin.

The reaction between the polyol (a1) and the polyisocyanate (a2) is carried out, for example, in such a manner that the equivalent ratio of the isocyanate group of the polyisocyanate (a2) to the hydroxyl group of the polyol (a1) , More preferably in the range of 0.9 to 1.5.

Examples of the organic solvent that can be used in the production of the urethane resin (A) include ketones such as acetone and methyl ethyl ketone; Ethers such as tetrahydrofuran and dioxane; Acetic acid esters such as ethyl acetate and butyl acetate; Nitriles such as acetonitrile; Amides such as dimethylformamide and N-methylpyrrolidone may be used alone or in combination of two or more.

In addition, at least one member selected from the group consisting of a compound having a primary amino group, a compound having a hydrazide group, and a hydrazine used in the production of the urethane resin (A) used in the present invention has excellent adhesion to various substrates It is used in giving. Among them, it is preferable to use hydrazine in order to further improve resistance to moisture and humidity. As the hydrazine, hydrazine hydrazine, which is a hydrate of hydrazine, may be used.

As the compound having the primary amino group, ethanolamine and the like can be used.

Examples of the hydrazide group-containing compound include dicarboxylic acid dihydrazide, carbohydrazide, and 1,3-bis (hydrazinocarbonoethyl) -5-isopropylhydantoin. It is preferred to use a disodium hydrogen carbonate or a carbhydrazide.

The dicarboxylic acid dihydrazide includes, for example, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide;棺 -semicarbazide propionic acid hydrazide, and the like, or a combination of two or more thereof. Among them, it is preferable to use adipic acid dihydrazide in order to give excellent adhesion.

At least one member selected from the group consisting of a compound having a primary amino group, a compound having a hydrazide group and a hydrazine is a compound wherein the total amount of the nitrogen atom of the primary amino group, hydrazide group and hydrazine, (Equivalence ratio) of the isocyanate group of the urethane resin obtained by reacting the polyisocyanate (a2) with the isocyanate group is preferably 1 or less (equivalence ratio), more preferably 0.3 to 1 (equivalence ratio).

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

[Method 1] After neutralizing or quaternizing a part or all of the hydrophilic groups of the urethane resin obtained by reacting the polyol (a1) and the polyisocyanate (a2), water is added thereto to disperse the water, (A) is subjected to water dispersion by using at least one member selected from the group consisting of a compound having a hydroxyl group, a compound having a hydrazide group and hydrazine.

[Method 2] At least one member selected from the group consisting of the urethane resin obtained by reacting the polyol (a1) and the polyisocyanate (a2), the compound having the primary amino group, the compound having the hydrazide group and the hydrazine, (A) is produced by neutralizing or quaternizing part or all of the hydrophilic groups in the resulting urethane resin (A), and then water is added thereto to disperse the water Way.

In [Method 1] to [Method 2] described above, an emulsifier may be used if necessary. In addition, a machine such as a homogenizer may be used as needed in dispersing or dispersing the water.

Examples of the emulsifier include nonionic surfactants such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene sorbitol tetraoleate, polyoxyethylene / polyoxypropylene copolymer and the like Emulsifiers; Anionic emulsifiers such as fatty acid salts such as sodium oleate and the like, alkylsulfuric acid ester salts, alkylbenzenesulfonic acid salts, alkylsulfosuccinic acid salts, naphthalenesulfonic acid salts, polyoxyethylene alkylsulfuric acid salts, alkanesulfonate sodium salts and alkyldiphenylether sulfonic acid sodium salts ; Cationic emulsifiers such as alkylamine salts, alkyltrimethylammonium salts and alkyldimethylbenzylammonium salts. Among them, it is preferable to use an anionic or nonionic emulsifier basically from the viewpoint of maintaining the excellent storage stability of the heat sealant 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 (D) is obtained by dispersing the urethane resin (A) in an amount of 10% by mass to 50% , Which is preferable in order to improve the ease of production of the heat seal agent of the present invention and to produce a heat sealant having both excellent heat and humidity resistance and excellent adhesion to various substrates.

The urethane resin (A) water dispersion may be a mixture of two or more kinds of urethane resins having different compositions. Specifically, two or more kinds of urethane resins having different compositions of the polyol (a1) used in the production of the urethane resin may be used in combination.

Next, the polyolefin resin (B) used in the production of the heat sealant of the present invention will be described.

Examples of the polyolefin resin (B) used in the present invention include homopolymers and copolymers of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, Having a functional group [X] can be used.

Specific examples of the polyolefin resin (B) include an epoxy resin (C) of the crosslinking agent (C) among polyethylene, polypropylene, polybutadiene, ethylene-propylene copolymer, natural rubber, synthetic isoprene rubber, ethylene- Group or a functional group [X] capable of reacting with an isocyanate group. When the polyolefin resin (B) is a copolymer, it may be a random copolymer or a block copolymer.

Examples of the functional group [X] of the polyolefin resin (B) include a carboxyl group, for example, similar to the functional group [X] of the urethane resin (A). The functional group [X] may be the same functional group as the hydrophilic group of the polyolefin resin (B). Specifically, when a carboxyl group or a carboxyl group, which is an anionic group, is used as the hydrophilic group, the carboxyl group and the like may act as the functional group [X] during the crosslinking reaction.

Examples of the polyolefin resin (B) having a carboxyl group as the functional group [X] include a polyolefin resin obtained by reacting the polyolefin resin with an unsaturated carboxylic acid, a polyolefin resin obtained by reacting the polyolefin resin with a vinyl monomer, Based resin is preferably used.

The polyolefin resin having a carboxyl group as the functional group [X] can be produced, for example, by reacting a polyolefin resin with an unsaturated dicarboxylic acid such as (anhydrous) maleic acid.

Examples of the unsaturated dicarboxylic acid include maleic acid, fumaric acid, itaconic acid, citraconic acid and their anhydrides, unsaturated dicarboxylic acid esters (butyl maleate, dibutyl maleate, butyl itaconate, etc.) And at least one of these can be used. Of these, maleic anhydride is preferable.

The polyolefin resin (B) modified with the unsaturated carboxylic acid has an acid value in the range of 5 to 250. This prevents degradation of the resin hardened layer (heat seal layer) due to heat or water (moisture) And is preferable in preventing deterioration of adhesion to various substrates.

The modification of the polyolefin resin can be performed, for example, by heating the polyolefin resin and unsaturated dicarboxylic acid or the like, such as maleic acid, and reacting.

The polyolefin resin (B) is preferably used in an amount of from 20,000 to 500,000 to prevent deterioration of the resin cured layer (heat seal layer) due to heat or water (moisture) It is preferable to use one having a weight average molecular weight. Further, the weight average molecular weight refers to a value measured using gel permeation chromatography (GPC).

Next, the crosslinking agent (C) used in the present invention will be described.

The alkylated methylol melamine resin (c1) and the epoxy compound (c2) are used as the cross-linking agent (C) for the purpose of obtaining a heat sealant having both excellent heat resistance and excellent adhesion to various substrates. Are used in combination.

As the alkylated methylol melamine resin (c1), for example, a resin obtained by reacting a methylol melamine resin with a lower alcohol (an alcohol having 1 to 6 carbon atoms) such as methyl alcohol or butyl alcohol can be used. Specifically, an alkylated methylol melamine resin having an imino group, an alkylated methylol melamine resin having an amino group, and the like can be used.

Examples of the methylolmelamine resin include a methylol-type melamine resin having an amino group obtained by condensing melamine and formaldehyde, a methylol-type melamine resin having an imino group, a trimethoxymethylol-type melamine resin, a hexamethoxymethylolmelamine resin Etc., and it is preferable to use a trimethoxy methylol type melamine resin or a hexamethoxymethylol type melamine resin.

As the epoxy compound (c2), those having an epoxy group of preferably 2 to 5, more preferably 3 to 4, can be used.

Examples of the epoxy compound (c2) include epoxy resins such as bisphenol A epichlorohydrin type, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1 , Hexanediol glycidyl ether, trimethylol propane polyglycidyl ether, diglycidyl aniline, diamine glycidyl amine, N, N, N ', N'-tetraglycidyl-m-xylyl 1,3-bis (N, N'-diamine glycidylaminomethyl) cyclohexane, and the like can be used.

Among them, the epoxy compound (c2) preferably has an epoxy equivalent of 100 to 300 in terms of imparting durability, and more specifically, is selected from the group consisting of trimethylolpropane polyglycidyl ether and glycerin triglycidyl ether It is more preferable to use at least one of them.

As the epoxy compound (c2), an epoxy compound having a hydrolyzable silyl group may also be used.

Examples of the epoxy compound having a hydrolyzable silyl group include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, and the like can be used.

The alkylated methylol melamine resin (c1) is preferably used in an amount of 3% by mass to 50% by mass relative to the total mass of the urethane resin (A) and the polyolefin resin (B) And more preferably in a range of 0.1 to 5 mass%. As a result, the deterioration of the heat-seal layer and the adherence of the heat-seal layer are not caused irrespective of the influence of heat or water (moisture), and further excellent moisture resistance and excellent adherence to various substrates .

The amount of the alkylated methylol melamine resin (c1) to be used is preferably in the range of 10% by mass to 30% by mass with respect to the total mass of the urethane resin (A) and the polyolefin resin (B) Which is preferable in achieving both heat resistance and excellent adhesion to various substrates.

As the crosslinking agent (C), it is preferable that the epoxy compound (c2) is added to the total amount (molar number) of the functional group [X] of the urethane resin (A) and the polyolefin resin (B) (molar number) of the epoxy group / the total amount (mol number) of the functional group [X]) of the amount of the epoxy group of the epoxy group (c2) to be used is preferably in the range of 5/1 to 1/5. As a result, it is possible to form a heat-seal layer having a rigid crosslink density at the time of curing by heating or the like, so that the deterioration of the heat-seal layer or the adhesion of the heat- It is possible to achieve both excellent moisture resistance and heat resistance that do not cause deterioration and more excellent adhesion to various substrates.

The use ratio [the amount of the substance of the epoxy group / the total amount of the substance of the functional group [X]] is preferably in the range of 2/1 to 1/5, and further satisfies both of excellent moisture resistance and excellent adhesion to various substrates .

The alkylated methylol melamine resin (c1) and the epoxy compound (c2) both have a better moisture resistance and excellent adhesion to various substrates. The mass ratio [the alkylated methylol melamine resin (c1 ) / Epoxy compound (c2)] is preferably in the range of 7/1 to 1/4, more preferably 5/1 to 1/4.

As the crosslinking agent (C), other crosslinking agents may be used in combination with the alkylated methylol melamine resin (c1) and the epoxy compound (c2), if necessary. Examples thereof include tolylene diisocyanate, chlorophenylenediisocyanate, An isocyanate compound such as diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate, an isocyanate compound obtained by subjecting them to a divalent or higher alcohol such as trimethylolpropane, An isocyanate compound, an anurate compound, a buret-type compound and the like can be used.

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

Examples of the aqueous medium (D) used in the present invention include water, an organic solvent which is miscible with water, and mixtures thereof. Examples of the organic solvent to be mixed with water include alcohols such as methanol, ethanol, n-propanol and isopropanol; Ketones such as acetone and methyl ethyl ketone; Polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; Alkyl ethers of polyalkylene glycols; And lactam such as N-methyl-2-pyrrolidone. In the present invention, water alone or a mixture of water and an organic solvent which is miscible with water may be used, or only an organic solvent which is miscible with water may be used. In view of safety and load to the environment, a mixture of water alone or an organic solvent which is miscible with water and water is preferable, and water alone is particularly preferable.

The aqueous medium (D) is preferably contained in an amount of 10% by mass to 90% by mass, and more preferably 30% by mass to 85% by mass, based on the total amount of the heat sealant of the present invention. It is preferable to improve the coating workability and the like of the heat seal agent of the invention and to achieve both adhesion and heat resistance.

The heat sealant of the present invention can be obtained, for example, by mixing the aqueous dispersion of the urethane resin (A) obtained by the above method, the aqueous dispersion of the polyolefin resin (B) and the crosslinking agent (C) Can be manufactured. The crosslinking agent (C) may be prepared by mixing the alkylated methylol melamine resin (c1) and the epoxy compound (c2) in advance or by mixing them separately with an aqueous dispersion of the urethane resin (A) or the polyolefin resin (B) To the aqueous dispersion of water.

The heat sealant of the present invention obtained by the above method may contain other additives as necessary in addition to the above components.

Examples of the additives include antioxidants, light stabilizers, plasticizers, film forming auxiliaries, leveling agents, foaming agents, thickening agents, coloring agents, flame retardants, other water-soluble resins and various fillers, have.

As the additive, for example, a surfactant may be used from the viewpoint of further improving the dispersion stability of the heat sealant of the present invention. However, it is preferable to use the surfactant in a range of 20 parts by mass or less based on 100 parts by mass of the total amount of the urethane resin (A) and the polyolefin resin (B), because the surfactant sometimes lowers the adhesiveness and water resistance of the obtained film And it is preferable not to use them as much as possible.

The heat sealant of the present invention can form a heat seal layer having excellent adhesion to a substrate and excellent heat and humidity resistance. Particularly, since the heat sealant of the present invention has excellent adhesion to both the polar base material (E) and the non-polar base material (F), the heat sealant for bonding the polar base material (E) It can be used properly. Specifically, a non-polar substrate composed of an ethylene-vinyl acetate copolymer, polyvinyl butyral, glass or the like and constituting the opposite surface of the light receiving surface constituting the solar cell module, and a non-polar substrate made of polyethylene terephthalate, polycarbonate or polyamide As a heat sealant for bonding a polar substrate (back sheet layer) constituted by a glass substrate or the like. Further, a non-polar substrate made of an ethylene-vinyl acetate copolymer, polyvinyl butyral, glass or the like constituting the opposite surface of the light receiving surface constituting the solar cell module and a non-polar substrate made of a polypropylene resin ) As a heat sealant for bonding.

Examples of the substrate on which the heat seal layer can be formed include various plastics, films, metals, glass, paper, and wood.

Examples of the polar substrate include a polyethylene terephthalate substrate, a polycarbonate substrate, and a polyamide substrate.

Examples of the non-polar substrate include substrates composed of ethylene-vinyl acetate copolymer, polyvinylidene fluoride resin, polyvinyl fluoride resin, ethylene-vinyl alcohol copolymer, polyvinyl butyral, glass and the like.

The surface of the base material may be subjected to surface treatment in advance, and specifically, it is preferable that corona treatment is performed. When a reactive group such as a carbonyl group is formed on the surface of the substrate by the corona treatment, a bond with the urea bond of the urethane resin (A) contained in the heat sealant of the present invention is formed. As a result, It is presumed that it can be improved.

The heat sealant of the present invention can be applied to the surface of the substrate and dried to form a resin layer formed by crosslinking to some extent. Since the surface of the resin layer has almost no tackiness before heating, it is possible to store the member in which the resin layer has been formed in advance on the surface of the substrate in a laminated state.

Next, when another base material is mounted on the surface of the resin layer and heated, the resin layer is melted and the hydroxyl group generated by the crosslinking reaction reacts with the hydrolyzable silyl group or the like of the epoxy compound (c2) , A heat-seal layer exhibiting adhesion capable of firmly adhering both substrates is formed. Since the heat-seal layer formed after the crosslinking reaction is excellent in the heat and humidity resistance, it is possible to prevent deterioration of the heat-seal layer due to the influence of heat or water (moisture).

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

Particularly, in the case of applying the heat sealant to the surface of a plastic substrate such as a polyethylene terephthalate film, it is preferable that, in the course of biaxial stretching the plastic substrate at a temperature of about 200 캜, And then forming a heat-seal layer by cross-linking reaction may be employed.

When the heat sealant is applied to the surface of a plastic substrate such as a polyethylene terephthalate film, the plastic substrate obtained by biaxially stretching is once wound on a roll or the like, and then the plastic substrate is taken out from the roll , And an off-line coating method in which the heat sealant is applied to the surface thereof may be employed.

The off-line coating method is preferably carried out at a temperature of about 150 캜 or less so as not to impair the dimensional stability of the plastic substrate.

By the above method, the heat seal layer can be formed by crosslinking and curing the heat seal agent on the surface of the substrate.

When a heat sealant of the present invention is applied and dried on the surface of one base material by the above method to form a resin layer on the surface of the base material, another base material is placed on the surface of the resin layer , Followed by heating at approximately 100 to 160 캜 under a reduced or pressurized state to obtain a bonded laminate thereof.

Since the laminate has excellent resistance to moisture and humidity, it can be used for various purposes including a solar cell module constituting a solar cell device and an automobile interior material.

In general, the solar cell module has a structure in which a surface including an ethylene-vinyl acetate copolymer or the like constituting a surface opposite to the surface that receives sunlight is formed of polyethylene terephthalate, A laminate structure in which a back sheet layer including a polypropylene resin or the like is formed is often provided. The heat sealant of the present invention can be appropriately used for bonding.

Specifically, as the solar cell module, a heat seal layer formed using the heat sealant is laminated on a surface of the ethylene-vinyl acetate copolymer constituting the opposite surface of the light receiving surface of the solar cell module, And a structure in which a layer including a polyethylene terephthalate base material, a polypropylene base material, a polycarbonate base material, or a polyamide base material is laminated on the surface of the heat-seal layer.

Examples of the method for producing the solar cell module include the following methods.

First, a laminated sheet having a heat sheet layer formed by applying the heat sealant to the surface of a polyethylene terephthalate substrate, a polypropylene substrate, a polycarbonate substrate or a polyamide substrate in advance is prepared.

Next, the heat-sealable layer of the laminated sheet is brought into contact with the surface of the ethylene-vinyl acetate copolymer constituting the opposite surface of the light-receiving surface of the solar cell module, and heated to heat the polyethylene terephthalate- The surface including the ethylene-vinyl acetate copolymer is bonded. Thus, the solar cell module can be manufactured.

The solar cell module obtained by such a method is excellent in durability against heat and humidity even when it is used outdoors for a long time.

Example

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples.

[Production Example 1]

In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube, 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000), 79.8 parts by mass of dimethylolpropionic acid, 672.7 parts by mass of methyl ethyl ketone And then 255.6 parts by mass of tolylene diisocyanate was added. Then, 0.1 part by mass of dibutyltin dilaurate was added and the mixture was allowed to react at 80 占 폚 for about 4 hours to obtain an urethane prepolymer having an isocyanate group at the terminal (Mass ratio of isocyanate group (isocyanate group content) to the urethane prepolymer: 2.1 mass%) was obtained.

Next, the methyl ethyl ketone solution of the urethane prepolymer obtained by the above method was cooled to 40 DEG C, and 69.3 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane prepolymer.

Next, 3079.2 parts by mass of ion-exchanged water was added, and 20.97 parts by mass of 80 mass% hydrazine hydrate (hydrazine monohydrate, 80 mass% hydrazine) was added to react.

After completion of the reaction, methyl ethyl ketone was distilled off under reduced pressure, and ion-exchanged water was added so that the non-volatile fraction thereof became 35 mass%, thereby obtaining a composition (I).

[Production Example 2]

In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube, 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000), 79.8 parts by mass of dimethylolpropionic acid, 672.7 parts by mass of methyl ethyl ketone And then 255.6 parts by mass of tolylene diisocyanate was added. Then, 0.1 part by mass of dibutyltin dilaurate was added and the mixture was allowed to react at 80 占 폚 for about 4 hours to obtain an urethane prepolymer having an isocyanate group at the terminal (Isocyanate group content: 2.1% by mass) was obtained.

Next, the methyl ethyl ketone solution of the urethane prepolymer obtained by the above method was cooled to 40 캜, and 69.3 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane prepolymer.

Next, 3130.9 parts by mass of ion-exchanged water was added, and 116.7 parts by mass of adipic acid dihydrazide was added and reacted.

After completion of the reaction, methyl ethyl ketone was distilled off under reduced pressure, and ion-exchanged water was added so that the non-volatile fraction thereof became 35 mass%, thereby obtaining a composition (II).

[Production Example 3]

In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube, 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000), 79.8 parts by mass of dimethylolpropionic acid, 672.7 parts by mass of methyl ethyl ketone And then 255.6 parts by mass of tolylene diisocyanate was added. Then, 0.1 part by mass of dibutyltin dilaurate was added and the mixture was allowed to react at 80 占 폚 for about 4 hours to obtain an urethane prepolymer having an isocyanate group at the terminal (Isocyanate group content: 2.1% by mass) was obtained.

Next, the methyl ethyl ketone solution of the urethane prepolymer obtained by the above method was cooled to 40 캜, and 69.3 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane prepolymer.

Next, 3149.2 parts by mass of ion-exchanged water was added, and 93.2 parts by mass of hydrazine (hydrazine monohydrate, 80% by mass relative to the total of hydrazine) of 80% by mass was added and reacted.

After completion of the reaction, methyl ethyl ketone was distilled off under reduced pressure, and ion-exchanged water was added so that the non-volatile fraction thereof became 35 mass%, thereby obtaining a composition (III).

[Production Example 4]

Necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube was charged with 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000), 21.2 parts by mass of 1,4-butanediol, And 784.9 parts by mass of methyl ethyl ketone were added and uniformly mixed. Then, 336.0 parts by mass of isophorone diisocyanate was added, and then 0.1 part by mass of dibutyltin dilaurate was added. The mixture was reacted at 80 DEG C for about 4 hours To obtain a methyl ethyl ketone solution of a urethane prepolymer having an isocyanate group (isocyanate group content: 2.1 mass%) at the terminal.

Next, the methyl ethyl ketone solution of the urethane prepolymer obtained by the above method, 13.6 parts by mass of ethanolamine and 189 parts by mass of methyl ethyl ketone were mixed and reacted to obtain a methyl ethyl ketone solution of a urethane resin having a primary amino group at the terminal ≪ / RTI >

Next, the methyl ethyl ketone solution of the urethane resin obtained by the above method was cooled to 40 DEG C, and 69.0 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane resin. Thereafter, methyl ethyl ketone was distilled off , And ion-exchanged water was added so that the non-volatile content thereof became 35 mass%, thereby obtaining the composition (IV).

[Production Example 5]

1000 parts by mass of Forester VS-1236 (an aqueous dispersion of maleic anhydride-modified polyolefin made by Seiko PMC Corporation, weight average molecular weight: 70000) was introduced while introducing nitrogen gas in a reactor equipped with a thermometer, a nitrogen gas introducing tube and a stirrer And the mixture was stirred at 80 ° C for 3 hours to melt. Subsequently, the mixture was cooled to 50 ° C, and 180 parts by mass of triethylamine was added to neutralize the mixture. Then, 2153 parts by mass of water was added thereto to obtain a composition V).

[Production Example 6]

In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube, 1000 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000), 79.8 parts by mass of dimethylolpropionic acid, 672.7 parts by mass of methyl ethyl ketone , 255.6 parts by weight of tolylene diisocyanate was added and then 0.1 part by weight of dibutyltin dilaurate was added and the mixture was allowed to react at 80 DEG C for about 4 hours to obtain a urethane prepolymer having an isocyanate group at the molecular end To obtain a methyl ethyl ketone solution of a polymer (isocyanate group content: 2.1% by mass).

Next, the methyl ethyl ketone solution of the urethane prepolymer obtained by the above method was cooled to 40 캜, and 69.3 parts by mass of triethylamine was added to neutralize the carboxyl group in the urethane prepolymer.

Next, 3122.6 parts by mass of ion-exchanged water was added, and 60.3 parts by mass of carbohydrazide was added and reacted.

After completion of the reaction, methyl ethyl ketone was distilled off under reduced pressure, and ion-exchanged water was added so that the non-volatile content thereof became 35 mass%, thereby obtaining a composition (VI).

[Example 1]

100 parts by mass of the composition (I) obtained in Preparation Example 1 and 78 parts by mass of the composition (V) obtained in Preparation Example 5 were mixed. Subsequently, 5 parts by mass of Beckamine M-3 (made by DIC Corporation, trimethoxy methylol type melamine resin, nonvolatile matter 80% by mass) and 5 parts by mass of Denacol EX-321 (manufactured by Nagase ChemteX K.K., trimethylolpropane (X-1) containing a water-based resin composition (X-1) having a nonvolatile content of 20% by mass was prepared by adding water, and then adding 4 parts by mass of a thermosetting resin (polyvinyl alcohol, polyglycidyl ether, nonvolatile matter 100% ≪ / RTI >

[Example 2]

Except that 100 parts by mass of the composition (II) obtained in Preparation Example 2 was used in place of 100 parts by mass of the composition (I) obtained in Production Example 1, (X-2) was obtained.

[Example 3]

(X-3) was obtained in the same manner as in Example 1, except that 100 parts by mass of the composition (III) obtained in Preparation Example 3 was used instead of 100 parts by mass of the composition (I) obtained in Production Example 1 (X-3) was obtained.

[Example 4]

(X-4) was obtained in the same manner 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 Production Example 1 (X-4) containing the heat sealant (X-4).

[Example 5]

The same procedure as in Example 1 was carried out except that the amount of use of Beckamine M-3 (trimethoxy methylol type melamine resin manufactured by DIC Co., nonvolatile matter 80% by mass) was changed from 5 mass parts to 23 mass parts (X-5) containing the water-based resin composition (X-5) was obtained.

[Example 6]

The same procedure as in Example 1 was repeated, except that the amount of Denacol EX-321 (manufactured by Nagase ChemteX Corporation, trimethylolpropane polyglycidyl ether, nonvolatile content of 100% by mass) was changed from 4 parts by mass to 42 parts by mass , A heat sealant (X-6) containing the water-based resin composition (X-6) was obtained.

[Example 7]

The same procedure as in Example 1 was repeated, except that the amount of Denacol EX-321 (manufactured by Nagase ChemteX Corporation, trimethylolpropane polyglycidyl ether, nonvolatile matter 100% by mass) was changed from 4 parts by mass to 1 part by mass , A heat sealant (X-7) containing the water-based resin composition (X-7) was obtained.

[Example 8]

The amount of the composition (V) described in Production Example 5 was changed from 78 parts by mass to 175 parts by mass, and the amount of isophorone diisocyanate was changed to 78 parts by mass of Beckamine M-3 (trimethoxy methylol type melamine resin made by DIC Corporation, nonvolatile content 80% The amount used was changed from 5 parts by mass to 7 parts by mass and the amount of use of Denacol EX-321 (trimethylolpropane polyglycidyl ether, non-volatile fraction 100% by mass, manufactured by Nagase ChemteX KK) was changed to 4 parts by mass (X-8) containing the water-based resin composition (X-8) was obtained in the same manner as in Example 1, except that the amount of the heat-

[Example 9]

(Manufactured by DIC Corporation, hexamethoxymethylol type melamine resin, non-volatile matter content of 80% by mass) was used in place of Bicamin M-3 (trimethoxymethylol type melamine resin made by DIC Co., (X-9) containing the water-based resin composition (X-9) was obtained in the same manner as in Example 1, except that 5 parts by mass of water and 80% by mass of volatile components were used.

[Example 10]

Except that 100 parts by mass of the composition (VI) obtained in Preparation Example 6 was used in place of 100 parts by mass of the composition (I) obtained in Preparation Example 1, (X-10) was obtained.

[Comparative Example 1]

100 parts by mass of the composition (I) obtained in Preparation Example 1 and 78 parts by mass of the composition (V) obtained in Preparation Example 5 were mixed and stirred and water was added to obtain a water-based resin composition (X'-1 (X'-1) containing the heat sealant (X'-1).

[Comparative Example 2]

100 parts by mass of the composition (I) obtained in Preparation Example 1 and 78 parts by mass of the composition (V) obtained in Preparation Example 5 were mixed and stirred. Then, the mixture was stirred with Denacol EX-321 (manufactured by Nagase Chemtech Co., (X'-2) containing a water-based resin composition (X'-2) having a nonvolatile content of 20% by mass was obtained by mixing water and 4 parts by mass of a polyvinyl alcohol resin ).

[Comparative Example 3]

100 parts by weight of the composition (I) obtained in Preparation Example 1 and 78 parts by weight of the composition (V) obtained in Preparation Example 5 were mixed and stirred, followed by stirring with a solution of Becamin M-3 (trimethoxymethyl 5 parts by mass of a non-volatile component (X'-3) having a nonvolatile content of 20% by mass was obtained by mixing water and 5 parts by mass of a water-soluble resin composition (X'- .

[Comparative Example 4]

100 parts by mass of the composition (I) obtained in Preparation Example 1, 3 parts by mass of Beckamine M-3 (trimethoxy methylol type melamine resin, produced by DIC Corporation, nonvolatile matter 80% by mass), and Denacol EX-321 And 0.2 parts by mass of a non-volatile component (X'-OMe) having a nonvolatile content of 20% by mass was obtained by adding 0.2 parts by mass of a polyvinyl alcohol (manufactured by Nagase ChemteX KK, trimethylolpropane polyglycidyl ether, 4) containing a heat sealant (X'-4).

[Comparative Example 5]

100 parts by mass of the composition (V) obtained in Production Example 5, 2 parts by mass of Beckamine M-3 (trimethoxy methylol type melamine resin manufactured by DIC Corporation, nonvolatile matter 80% by mass), and Denacol EX-321 4 parts by mass of a non-volatile component (X'-OMe) having a nonvolatile content of 20% by mass was obtained by adding 4 parts by mass of a polyvinyl alcohol (manufactured by Nagase ChemteX KK, trimethylolpropane polyglycidyl ether, 5) containing a heat sealant (X'-5).

[Comparative Example 6]

(Manufactured by NIPPON POLYURETHANE CHEMICAL INDUSTRIES, LTD., Water dispersible polyisocyanate crosslinking agent (trade name), manufactured by Nippon Polyurethane Industry Co., Ltd.) instead of Denacol EX-321 (manufactured by Nagase ChemteX, trimethylolpropane polyglycidyl ether, (X'-7) containing a water-based resin composition (X'-7) was obtained in the same manner as in Example 1, except that 7 parts by mass of a nonvolatile matter (100%

[Comparative Example 7]

(Manufactured by NIPPON POLYURETHANE INDUSTRY CO., LTD., Water dispersible polyisocyanate crosslinking agent, nonvolatile matter (nonvolatile matter), and the like) was used in place of N-vinylpyrrolidone (trade name, available from Daineki Chemical Co., Ltd., (X'-8) containing the water-based resin composition (X'-8) was obtained in the same manner as in Example 1, except that 7 mass parts of the water-based resin composition (X'-

[Comparative Example 8]

(Manufactured by DIC Co., Ltd., water-dispersible carbodiimide) was used in place of Denacol EX-321 (manufactured by Nagase ChemteX Corporation, trimethylolpropane polyglycidyl ether, nonvolatile content of 100% (X'-9) containing the water-based resin composition (X'-9) was obtained in the same manner as in Example 1, except that 28 parts by mass of a water-insoluble resin .

[Comparative Example 9]

(Manufactured by NIPPON POLYURETHANE INDUSTRY CO., LTD., Water dispersible polyisocyanate crosslinking agent, nonvolatile matter (nonvolatile matter), and the like) was used in place of N-vinylpyrrolidone (trade name, available from Daineki Chemical Co., Ltd., 100 parts by mass) was used instead of 7 parts by mass of a polyvinyl butyral resin (trade name, manufactured by Nagase ChemteX KK, trimethylolpropane polyglycidyl ether, non-volatile fraction 100% by mass) (X'-10) was obtained in the same manner as in Example 1, except that 10 parts by mass of a water-dispersible carbodiimide compound (a water-dispersible carbodiimide compound, nonvolatile matter content: 40% by mass, manufactured by DIC Corporation) (X'-10) was obtained.

[Evaluation method of adhesion property to polar base material and non-polar base material]

The heat sealant obtained in the above Examples and Comparative Examples was coated on the surface of the film containing polyethylene terephthalate as the polar base material so that the dry film thickness was 5 占 퐉 and dried at 150 占 폚 for 5 minutes, Thereby obtaining a laminate having a resin layer crosslinked on its surface.

A film (5 cm in length x 1 cm in width) containing ethylene-vinyl acetate as a non-polar substrate was placed on the surface of the resin layer of the laminate, and then they were subjected to a heat treatment at 150 ° C for 15 minutes And a film containing polyethylene terephthalate and a film containing ethylene-vinyl acetate were adhered via the resin cured layer (heat-seal layer) to obtain a laminate.

[Test method for adhesion]

The adhesion of the laminate immediately after the production by the above method was evaluated by the T-type peel test method (1000N cell) using a tensile tester (Autograph of Shimazu Seisakusho Co., Ltd.). The adhesion was evaluated based on the adhesion between the heat-seal layer and the film containing ethylene-vinyl acetate.

The peel strength measured by the above method was about 30 N / cm or more, and the peel strength was 35 N / cm or more.

[Evaluation of Humidity Resistance]

The laminate thus obtained was allowed to stand in a thermo-hygrostat under the conditions of 120 占 폚 and 100% RH for 72 hours to conduct a wet heat test. The adhesion of the stacked body after the above-mentioned standing was measured and evaluated by the same method as described above.

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

Further, the ratio of the peel strength (retention ratio) of the laminate after the resistance to heat peeling to the peel strength of the laminate immediately after the production is 50% or more is evaluated to be excellent in heat and humidity resistance, And evaluated as excellent.

The "content of alkylated methylolmelamine resin [mass%]" in the table indicates the mass ratio of the alkylated methylol melamine resin to the total mass of the urethane resin (A) and the polyolefin resin (B).

The total amount of the epoxy group (the amount of the epoxy group / the total amount of the functional group [X]) of the urethane resin (A) and the polyolefin resin (B) Total material amount.

&Quot; M-3 " in the table indicates Beccamine M-3 (trimethoxy methylol type melamine resin, nonvolatile content 80% by mass) made by DIC Corporation.

"EX-321" in the table represents Denacol EX-321 (trimethylolpropane polyglycidyl ether, nonvolatile content of 100% by mass) manufactured by Nagase ChemteX Corporation.

&Quot; Aquanate-210 " in the table indicates Aquanate 210 (water dispersible polyisocyanate crosslinking agent, nonvolatile content 100% by mass) manufactured by Nippon Polyurethane Industry Co., Ltd.

"WSA-950" in the table represents Watersol WSA-950 (epoxy compound having a hydrolyzable silyl group, nonvolatile content of 100% by mass) manufactured by DIC Corporation.

&Quot; CS-7 " in the table represents Hydran acidomer CS-7 (water-dispersible carbodiimide compound, nonvolatile content 40 mass%) made by DIC Corporation.

The heat sealant described in Example 1 obtained using the above hydrazine had excellent adhesion and wet heat resistance. In addition, the heat sealants described in Examples 2 and 10 obtained using adipic acid dihydrazide or carbohydrazide had excellent adhesion and good heat and humidity resistance.

In addition, the heat seal system described in Example 3 in which hydrazine was used in excess was also provided with excellent adhesion and somewhat good resistance to humidity and humidity. Further, the heat sealant obtained using ethanolamine had good adhesion and wet heat resistance.

In addition, the heat sealants described in Examples 5 to 7 and 9, in which the ratio and type of the alkylated methylol melamine resin and the epoxy compound were changed, had excellent adhesion and good heat and humidity resistance. The heat sealant obtained in Example 9 in which the mass ratio of the urethane resin and the polyolefin resin was changed was excellent in adhesion and humidity resistance.

On the other hand, the heat sealant described in Comparative Example 1 obtained without using a cross-linking agent was insufficient in terms of adhesion. In addition, the heat sealants described in Comparative Examples 2 and 3, which were obtained without using alkylated methylol melamine or epoxy compound as a crosslinking agent, had good adhesion but remarkably decreased adhesiveness after the moisture resistance test. In addition, the heat sealants described in Comparative Examples 4 and 5, which were obtained without using either the urethane resin or the polyolefin resin, were insufficient in terms of adhesion.

The heat sealants described in Comparative Examples 6 to 9 obtained by using other crosslinking agents in combination in place of the alkylated methylol melamine and epoxy compounds as the crosslinking agent had good adhesion but showed a remarkable decrease in adhesion after the anti- I raised it.

Claims (6)

As a heat sealant containing a urethane resin (A), a polyolefin resin (B), a crosslinking agent (C) and an aqueous medium (D)
Wherein the urethane resin (A) is obtained by reacting an urethane resin having an isocyanate group with at least one member selected from the group consisting of a compound having a primary amino group, a compound having a hydrazide group, and hydrazine,
Wherein the crosslinking agent (C) contains an alkylated methylol melamine resin (c1) and an epoxy compound (c2), and either or both of the urethane resin (A) and the polyolefin resin (B) ]. ≪ / RTI > The thermoplastic resin composition according to claim 1, wherein the alkylated methylol melamine resin (c1) is contained in an amount of 5% by mass to 50% by mass relative to the total mass of the urethane resin (A) and the polyolefin resin (B) Wherein the ratio of the amount of the epoxy group of the epoxy compound (c2) to the total amount of the substance [X] (the amount of the epoxy group / the total amount of the functional group [X]) is 5/1 to 1/5. The heat sealant according to claim 1, wherein the functional group [X] is at least one selected from the group consisting of a carboxyl group, a hydroxyl group and an amino group. The heat sealer according to claim 1, wherein the epoxy compound (c2) is at least one selected from the group consisting of trimethylolpropane polyglycidyl ether and glycerin triglycidyl ether. A heat seal layer formed by using the heat sealant described in any one of claims 1 to 4 is applied to the surface of the ethylene-vinyl acetate copolymer constituting the opposite surface of the light receiving surface of the solar cell module, And a structure in which a layer including a polyethylene terephthalate base material, a polypropylene base material, a polycarbonate base material or a polyamide base material is laminated on the surface of the heat-seal layer. A heat sealant as described in any one of claims 1 to 4 is applied to the surface of a polyethylene terephthalate base, a polypropylene base, a polycarbonate base or a polyamide base, and a heat sheet layer The laminated sheet,
A method for manufacturing a solar cell module, comprising the steps of: stacking a heat seal layer of the laminated sheet in contact with a surface of an ethylene-vinyl acetate copolymer constituting the opposite surface of the light receiving surface of the solar cell module, Way.