CN104093760A - Resin composition, two-component lamination adhesive, lamination film, and back sheet of solar cell - Google Patents

Abstract

Provided is a resin composition which can form a cured coating film exhibiting high strength, high bond strength and excellent long-term stability such that little deterioration in the bond strength is observed in a damp heat test and which can ensure excellent surface appearance of a laminate. Also provided are: a two-part laminating adhesive containing said resin composition; a laminated film having a layer made from the adhesive; and a backsheet for a solar cell. The resin composition comprises: a polyester polyurethane polyol which has a branched structure in the molecule and which has a weight-average molecular weight of 10,000 to 100,000 and a molecular weight distribution of 5.0 or more; a polyester polyol which has a branched structure in the molecule and which has a weight-average molecular weight of 10,000 to 50,000 and a molecular weight distribution of less than 5.0; a hydroxyl-containing epoxy resin which has a number-average molecular weight of 300 to 5,000; a hydroxyl-containing polycarbonate resin which has a number-average molecular weight of 300 to 3,000; and a polyisocyanate. The two-part laminating adhesive contains the composition.

Description

Resin composition, two-component lamination adhesive, lamination film, and back sheet of solar cell

technical field

The present invention relates to a resin composition, a two-component adhesive for lamination, a lamination film, and a back sheet of a solar cell, which are excellent in substrate adhesion under hot and humid conditions.

Background technique

In recent years, solar power generation has attracted attention as a representative of clean energy. The back sheet installed on the backmost side of the solar cell module is used to protect the power generation mechanism such as batteries and wiring from the external environment and maintain insulation. It is a layer made by bonding various functional films with an adhesive Pressed body. Adhesives used for such backsheets are required to have high adhesion to various films with different characteristics such as polyester film and polyvinyl fluoride film, and to be used for long-term maintenance in open air environments. Adhesive resistance to heat and humidity.

As such an adhesive for a back sheet, a polyurethane-based adhesive containing a main ingredient including a polyester polyol, a polyester polyurethane polyol, and a bisphenol-type epoxy resin, and a curing agent has been proposed (see Patent Document 1).

prior art literature

patent documents

Patent Document 1: Japanese Patent No. 4416047

Contents of the invention

The problem to be solved by the invention

However, the aforementioned polyurethane-based adhesives have the following problems in terms of stability over time: the strength of the coating film after curing is weak, the adhesive strength deteriorates in the heat and humidity resistance test, and the appearance after lamination is poor. The problem.

The problem to be solved by the present invention is to provide a strong coating film after curing, high adhesive strength, excellent stability over time such that the adhesive strength does not deteriorate in the heat and humidity resistance test, and excellent appearance after lamination. The resin composition of the present invention, a two-component adhesive for lamination containing the resin composition, a laminate film having a layer formed of the adhesive, and a back sheet of a solar cell.

solutions to problems

In order to solve the above problems, the inventors of the present invention conducted intensive studies and found that by using the following two-component curable resin composition, the strength of the cured coating film is strong, the adhesive strength is high, and the heat and humidity resistance test shows that: Excellent temporal stability without deterioration of adhesive strength, and excellent appearance after lamination processing, and completed the present invention. The two-component curable resin composition uses the following essential components as a main ingredient: (1) Polyester polyurethane polyol (A) having a branched structure in the molecule, a weight average molecular weight (Mw) in the range of 10,000 to 100,000, and a molecular weight distribution (Mw/Mn) of 5.0 or more, (2) having a branched structure in the molecule , a polyester polyol (B) having a weight average molecular weight (Mw) in the range of 10,000 to 50,000 and a molecular weight distribution (Mw/Mn) of less than 5.0, and further blending (3) number average molecular weight (Mn) The main component which is the hydroxyl-containing epoxy resin (C) in the range of 300-5000, (4) the hydroxyl-containing polycarbonate resin (D) whose number average molecular weight (Mn) is in the range of 300-3000, and its (5) Polyisocyanate (E) of the curing agent.

That is, the present invention relates to a resin composition characterized in that it contains the following components as essential components:

(1) A polyester polyurethane polyol (A) having a branched structure in the molecule, a weight average molecular weight (Mw) in the range of 10,000 to 100,000, and a molecular weight distribution (Mw/Mn) of 5.0 or more, and

(2) A polyester polyol (B) having a branched structure in a molecule, a weight average molecular weight (Mw) in the range of 10,000 to 50,000, and a molecular weight distribution (Mw/Mn) of less than 5.0.

The present invention also relates to a two-component adhesive for lamination containing (5) polyisocyanate (E) as a curing agent in addition to the above-mentioned component (A) and the above-mentioned component (B).

The present invention also relates to a laminated film comprising one or more films selected from the group consisting of polyester films, fluororesin films, polyolefin films, and metal foils and the above-mentioned two-component type lamination adhesive. The adhesive layer formed by the agent.

The present invention also relates to a solar cell backsheet having an adhesive layer formed of the above-mentioned two-component adhesive for lamination.

The effect of the invention

The resin composition of the present invention and the two-component adhesive for lamination containing the resin composition have strong coating film strength after curing, high adhesive strength, and do not deteriorate the adhesive strength in the heat and humidity resistance test. It is excellent in stability over time and also excellent in appearance after lamination, so it is useful as an adhesive for laminated films and back sheets of solar cells.

Detailed ways

The resin composition of the present invention contains (1) a polyester polyurethane polyol (A) having a branched structure in the molecule, a weight average molecular weight (Mw) in the range of 10,000 to 100,000, and a molecular weight distribution (Mw/Mn) of 5.0 or more. Element.

The above-mentioned polyester polyurethane polyol (A) has a branched structure in the molecule, and the final cured product has a high crosslinking density, so it does not swell even under hot and humid conditions, and can maintain high adhesiveness.

Moreover, the weight average molecular weight (Mw) of the said polyester polyurethane polyol (A) is the range of 10000-100000. By making weight average molecular weight (Mw) into the said range, hardened|cured material will show high strength, and will become the resin composition excellent in the initial stage adhesive strength. And the viscosity of the resin composition is suitable for coating. When the weight average molecular weight (Mw) of the said polyester polyurethane polyol (A) is less than 10000, there exists a tendency for the initial adhesive strength to fall, and since viscosity is low, it becomes the resin composition which is difficult to coat uniformly.

On the other hand, when the weight average molecular weight (Mw) of the said polyester polyurethane polyol (A) exceeds 100000, since it exists in the tendency for a viscosity to become high, it becomes a resin composition which is difficult to coat. Regarding the weight-average molecular weight (Mw) of such a polyester polyurethane polyol (A), it is possible to obtain a resin composition with high initial adhesive strength and excellent substrate adhesion under hot and humid conditions. The weight average molecular weight (Mw) is preferably in the range of 12,000 to 90,000.

The molecular weight distribution (Mw/Mn) of the said polyester polyurethane polyol (A) is 5.0 or more. By setting the molecular weight distribution (Mw/Mn) within the above range, the effect of improving the adhesion to the base material due to the low molecular weight component and the effect of increasing the strength of the cured product due to the high molecular weight component can be exhibited at the same time Therefore, it becomes the resin composition which is excellent in the adhesiveness of the base material under the heat-and-humidity condition, and has high initial adhesive strength. When the molecular weight distribution (Mw/Mn) is less than 5.0, the appearance after lamination tends to deteriorate. The molecular weight distribution (Mw/Mn) of the polyester polyurethane polyol (A) is preferably in the range of 5 to 25, more preferably The range of 5 to 15.

In addition, the polyester polyurethane polyol (A) preferably has a number average molecular weight (Mn) of 3,000 to 20,000 from the viewpoint of excellent substrate adhesion under heat and humidity conditions and a resin composition having a viscosity suitable for coating. range, more preferably in the range of 5,000 to 10,000.

In addition, in this invention, weight average molecular weight (Mw) and number average molecular weight (Mn) are the values measured by the gel permeation chromatography (GPC) of the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation

Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation + TSK-GEL SuperHZM-M manufactured by Tosoh Corporation × 4

Detector: RI (differential refractometer)

Data processing: Multi station GPC-8020 model II manufactured by Tosoh Corporation

Determination conditions: column temperature 40°C

Solvent Tetrahydrofuran

      Flow rate   0.35ml/min

Standard : Monodisperse polystyrene

Sample : A substance obtained by filtering a tetrahydrofuran solution of 0.2% by mass in terms of resin solid content with a microfilter (100 μl)

In addition, the hydroxyl value of the polyester polyurethane polyol (A) is preferably in the range of 5 to 30 mgKOH/g, and more preferably in the range of 7 to 15 mgKOH/g, from the viewpoint of excellent substrate adhesion under hot and humid conditions. . When the hydroxyl value of the aforementioned polyester polyurethane polyol (A) is greater than 30 mgKOH/g, there is a tendency that the heat-and-moisture resistance is deteriorated. The reaction rate decreases and the adhesiveness tends to deteriorate.

The aforementioned polyester polyurethane polyol (A) is obtained by, for example, reacting a polybasic acid (E), a polyol (F), and a polyisocyanate (G). In this case, in order to introduce a branched structure into the molecule of polyester polyurethane polyol (A), any one or more raw material components of polybasic acid (E), polyol (F) and polyisocyanate (G) use trifunctional the above compounds.

Examples of the polybasic acid (E) include a dibasic acid (E1) and a trifunctional or higher polybasic acid (E2).

Examples of the dibasic acid (E1) include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and undecanedioic acid. , dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, two Aliphatic dibasic acids such as dodecanedioic acid; Aliphatic dibasic acids such as tetrahydrophthalic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, Saturated dibasic acids and their anhydrides; aliphatic unsaturated dibasic acids such as tetrahydrophthalic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, and Its anhydrides; aromatic dibasic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid and their anhydrides.

Examples of the polybasic acid (E2) having three or more functions include aliphatic tribasic acids such as 1,2,5-hexanetricarboxylic acid and 1,2,4-cyclohexanetricarboxylic acid; Aromatic tribasic acids such as trimellitic anhydride, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid and their anhydrides.

Here, by using the above-mentioned trifunctional or higher polybasic acid (E2), a branched structure can be introduced into the molecule of the polyester polyurethane polyol (A) of the present invention.

These polybasic acids (E) may be used alone or in combination of two or more. Among them, it is preferable to use an aliphatic polybasic acid and an aromatic polybasic acid in combination from the viewpoint of obtaining a resin composition having excellent substrate adhesion under hot and humid conditions and a viscosity suitable for coating. In this case, aliphatic polybasic acids are preferably used. The content of the family polybasic acid in the total polybasic acid components is in the range of 10 to 30 mol%, and the range of the aromatic polybasic acid is in the range of 50 to 90 mol%. In addition, the above-mentioned aliphatic polybasic acid is preferably adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, Undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid Alkanedioic acid, eicosanedioic acid, 1,2,5-hexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid and other aliphatic polybasic compounds having 6 to 20 carbon atoms acid, more preferably suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, 1,2,5-hexanetricarboxylic acid, 1,2, An aliphatic polybasic acid having 8 to 13 carbon atoms such as 4-cyclohexanetricarboxylic acid.

In addition, for the purpose of adjusting the molecular weight and viscosity of the polyester polyurethane polyol (A), formic acid, acetic acid, propionic acid, butyric acid, valeric acid, Monocarboxylic acids such as caproic acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid, dodecanoic acid, myristic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, benzoic acid.

Examples of the polyol (F) include diols (F1) and trifunctional or higher polyols (F2).

Examples of the diol (F1) include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, 2,2- Dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol Diol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohexane, 2,2,4-tris Aliphatic diols such as methyl-1,3-pentanediol; ether diols such as polyoxyethylene diol and polyoxypropylene diol; Produced by ring-opening polymerization of compounds containing cyclic ether bonds such as propane, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether modified polyether diol; lactone polyester polyol obtained by the polycondensation reaction of the aforementioned aliphatic diol and various lactones such as ε-caprolactone; bisphenol A, bisphenol F and the like Bisphenol; an alkylene oxide adduct of bisphenol obtained by adding ethylene oxide, propylene oxide, etc. to bisphenols such as bisphenol A and bisphenol F, and the like.

Examples of the trifunctional or higher polyhydric alcohol (F2) include aliphatic polyhydric alcohols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol; Cyclic ether linkages with ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, etc. The modified polyether polyol obtained by the ring-opening polymerization of the compound; the lactone polyester polyol obtained by the polycondensation reaction of the aforementioned aliphatic polyol and lactones such as ε-caprolactone, etc.

A branched structure can be introduced into the molecule of the polyester polyurethane polyol (A) of the present invention by using the above-mentioned polyol (F2) having more than three functions.

The above polyols (F) may be used alone or in combination of two or more. From the viewpoint of forming a resin composition excellent in coatability, the content of the aliphatic polyol in the total polyol components is preferably 40 mol % or more, more preferably 80 mol % or more. In addition, the aforementioned aliphatic polyol is preferably an aliphatic polyhydric alcohol having 5 or more carbon atoms, more preferably the aforementioned aliphatic polyhydric alcohol, from the viewpoint of obtaining a resin composition that is more excellent in substrate adhesion under humid heat conditions. diol.

Examples of the polyisocyanate (G) include a diisocyanate compound (G1) and a trifunctional or higher polyisocyanate compound (G2).

Examples of the diisocyanate compound (G1) include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4, Aliphatic diisocyanates such as 4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, m-tetramethylxylylene diisocyanate; cyclohexane-1,4-diisocyanate, isofor Alone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, isopropylidene Cycloaliphatic diisocyanates such as dicyclohexyl-4,4'-diisocyanate, norbornane diisocyanate; 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4' -Diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, Aromatic diisocyanate such as 1,4-phenylene diisocyanate, toluene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, etc.

The aforementioned polyisocyanate compound (G2) having more than three functions includes, for example, an adduct-type polyisocyanate compound having a urethane bond site in the molecule, a ureate-type polyisocyanate compound having an isocyanurate ring structure in the molecule, etc. compound.

The adduct type polyisocyanate compound having a urethane bond site in the molecule can be obtained, for example, by reacting a diisocyanate compound with a polyhydric alcohol. The diisocyanate compound used for this reaction includes, for example, various diisocyanate compounds exemplified as the aforementioned diisocyanate compound (G1), and these may be used alone or in combination of two or more. In addition, examples of the polyol compound used in this reaction include various polyol compounds exemplified as the above-mentioned polyol (F), polyester polyol obtained by reacting a polyol with a polyacid, and the like, and these compounds can be individually They may be used alone or in combination of two or more.

The said urate type polyisocyanate compound which has an isocyanurate ring structure in a molecule|numerator can be obtained, for example by making a diisocyanate compound react with monohydric alcohol and/or dihydric alcohol. The diisocyanate compound used for this reaction includes, for example, various diisocyanate compounds exemplified as the aforementioned diisocyanate compounds, and these may be used alone or in combination of two or more. In addition, examples of monohydric alcohols used in this reaction include hexanol, 2-ethylhexanol, octanol, n-decyl alcohol, n-undecanol, n-dodecanol, and n-tridecyl alcohol. , n-tetradecanol, n-pentadecanol, n-heptadecanol, n-stearyl alcohol, n-nonadecanol, eicosanol, 5-ethyl-2-nonanol, trimethylnonanol Alcohol, 2-hexyldecanol, 3,9-diethyl-6-tridecanol, 2-isoheptylisoundecanol, 2-octyldodecanol, 2-decyltetradecane Alcohol etc., As a dihydric alcohol, the aliphatic diol etc. which were illustrated in the said polyol (F) are mentioned. These monoalcohols and diols may be used alone or in combination of two or more.

Here, a branched structure can be introduced into the molecule of the polyester polyurethane polyol (A) of the present invention by using the trifunctional or higher polyisocyanate compound (G2).

These polyisocyanate (G) may be used individually or in combination of 2 or more types. Among them, the aforementioned trifunctional or higher polyisocyanate compound (G2) is preferable, and the urate-type polyisocyanate compound is more preferable because a resin composition excellent in adhesive strength under wet heat conditions can be obtained. Moreover, it is preferable to use together the said diisocyanate compound (G1) and the said trifunctional or more polyisocyanate compound (G2) from the point which can adjust a resin composition to the viscosity suitable for coating easily. In this case, the mass ratio [(G1)/(G2)] of the two is preferably It is in the range of 50/50 to 5/95, more preferably in the range of 40/60 to 10/90, particularly preferably in the range of 30/70 to 15/85.

The trifunctional or higher functional component used in the production of the aforementioned polyester polyurethane polyol (A) may be any of the aforementioned polybasic acid (E2), the aforementioned polyol (F2) and the aforementioned polyisocyanate compound (G2). As mentioned above, it is preferable to use a polyisocyanate compound from the viewpoint that a resin composition excellent in adhesive strength under hot and humid conditions can be obtained and that the aforementioned polyester polyurethane polyol (A) can be easily produced in a shorter time. (G2).

As a method for producing the aforementioned polyester polyurethane polyol (A), for example, the following method is mentioned: in the presence of an esterification catalyst, the aforementioned polybasic acid (E) and the aforementioned polyol (F) are heated at 150 to 270° C. After reacting in a temperature range to obtain a polyester polyol, this polyester polyol and the aforementioned polyisocyanate (G) are reacted in a temperature range of 50 to 100° C. in the presence of a urethanization catalyst.

In addition, the resin composition of the present invention contains (2) a polyester polyol (B) having a branched structure in the molecule, a weight average molecular weight (Mw) in the range of 10000 to 50000, and a molecular weight distribution (Mw/Mn) of 5.0 or less. essential ingredient.

The above-mentioned polyester polyurethane polyol (A) has a branched structure in the molecule, and the final cured product has a high crosslinking density, so it does not swell even under hot and humid conditions, and can maintain high adhesiveness.

The aforementioned polyester polyol (B) has a branched structure in its molecule, and contributes to improvement of initial adhesiveness and heat-and-moisture-resistant adhesiveness, especially when used in a lamination adhesive.

Moreover, the weight average molecular weight (Mw) of the said polyester polyol (B) is the range of 10000-50000. By making weight average molecular weight (Mw) into the said range, hardened|cured material will show high strength, and will become the resin composition excellent in the initial stage adhesive strength. And the viscosity of the resin composition is suitable for coating. When the weight average molecular weight (Mw) of the said polyester polyol (B) is less than 10000, there exists a tendency for the initial adhesive strength to fall, and since viscosity is low, it becomes the resin composition which is difficult to coat uniformly. On the other hand, when the weight average molecular weight (Mw) of the said polyester polyol (B) exceeds 50000, since there exists a tendency for a viscosity to become high, it will become the resin composition which is difficult to coat. Regarding the weight-average molecular weight (Mw) of such a polyester polyol (B), it is important to obtain a resin composition with high initial adhesive strength and excellent substrate adhesion under hot and humid conditions. The average molecular weight (Mw) is preferably in the range of 12,000 to 40,000.

The molecular weight distribution (Mw/Mn) of the aforementioned polyester polyol (B) is less than 5.0. When the molecular weight distribution (Mw/Mn) is within the above range, when used as a two-component type lamination adhesive, the effect of excellent appearance after lamination processing can be exhibited. When the molecular weight distribution (Mw/Mn) of the polyester polyol (B) is 5.0 or more, when it is used as a two-component type lamination adhesive, the initial adhesiveness tends to decrease. The molecular weight distribution (Mw/Mn) of the polyester polyol (B) is preferably in the range of 1.0 to 5.0, more preferably in the range of 2.0 to 4.0.

In addition, the polyester polyol (B) preferably has a number average molecular weight (Mn) of 3,000 to 20,000 from the viewpoint of being a resin composition having excellent substrate adhesion under hot and humid conditions and a viscosity suitable for coating. The range is more preferably in the range of 5,000 to 10,000.

In addition, the hydroxyl value of the polyester polyol (B) is preferably in the range of 5 to 30 mgKOH/g, more preferably in the range of 7 to 15 mgKOH/g, from the viewpoint of excellent substrate adhesiveness under hot and humid conditions.

The aforementioned polyester polyol (B) is obtained by, for example, reacting a polybasic acid (E) with a polyol (F). In this case, in order to introduce a branched structure into the molecule of the polyester polyol (B), a trifunctional or higher functional compound is used as one or more raw material components of the polybasic acid (E) and the polyol (F).

The polybasic acid (E) and polyol (F) which are reaction raw materials of the said polyester polyol (B) can use the thing similar to the reaction raw material of the said polyester polyurethane polyol (A).

As a method for producing the aforementioned polyester polyol (B), for example, the following method is mentioned: in the presence of an esterification catalyst, the aforementioned polybasic acid (E) and the aforementioned polyol (F) are heated at a temperature of 150 to 270°C. response within the range.

The resin composition of the present invention contains the above-mentioned polyester polyurethane polyol (A) and polyester polyol (B) as the main ingredients necessary in a two-component curable composition, and is effective even for PVF ( Polyvinyl fluoride) film, PVDF (polyvinylidene fluoride) film and other fluorine-based substrates can also exhibit high adhesiveness, it is preferable to further contain a hydroxyl group-containing substrate having a number average molecular weight (Mn) of 300 to 5000 Epoxy resin (C). When the number average molecular weight (Mn) of the said epoxy resin (C) is less than 300, sufficient adhesive strength cannot be obtained, and when the number average molecular weight (Mn) exceeds 5000, the solubility in the resin composition of this invention falls. Among them, the number average molecular weight (Mn) is more preferably in the range of 400 to 2000 from the viewpoint of the solubility in the resin composition of the present invention and the substrate adhesiveness under humid heat conditions being more excellent.

As the aforementioned hydroxyl group-containing epoxy resin (C), for example, bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin; biphenyl type epoxy resin, tetramethyl Biphenyl type epoxy resins such as biphenyl type epoxy resins; dicyclopentadiene-phenol addition reaction type epoxy resins, and the like. These hydroxyl group-containing epoxy resins may be used alone or in combination of two or more. Among these, a bisphenol-type epoxy resin is preferable from the point which can obtain the resin composition excellent in the adhesiveness to the base material under the heat-and-moisture condition, and the initial stage adhesive strength.

From the viewpoint of being a resin composition excellent in substrate adhesion under hot and humid conditions, it is preferable that the resin composition of the present invention further contains, in addition to the above-mentioned components, a compound having a number average molecular weight (Mn) of 300 to 3000. Hydroxyl-containing polycarbonate resin (D). When the number average molecular weight (Mn) is less than 300, sufficient adhesive strength cannot be obtained, and when the number average molecular weight (Mn) exceeds 3000, the solubility in the resin composition of this invention falls. Among them, the number average molecular weight (Mn) is more preferably in the range of 400 to 2000 from the viewpoint of the solubility in the resin composition of the present invention and the substrate adhesiveness under humid heat conditions being more excellent.

The hydroxyl value of the hydroxyl group-containing polycarbonate resin (D) is preferably in the range of 20 to 300 mgKOH/g, and more preferably in the range of 40 to 250 mgKOH/g, from the viewpoint of a more curable resin composition. Moreover, polycarbonate diol is preferable from the point which is excellent in the base-material adhesiveness under the heat-and-moist condition.

The above-mentioned hydroxyl group-containing polycarbonate resin (D) can be produced by, for example, a method of subjecting a polyhydric alcohol and a carbonylating agent to polycondensation reaction.

As a polyhydric alcohol used for manufacture of the said hydroxyl-containing polycarbonate resin (D), the various polyhydric alcohol illustrated as the said polyol (F) is mentioned, for example.

The polyhydric alcohols may be used alone or in combination of two or more.

Examples of the carbonylating agent used in the production of the hydroxyl-containing polycarbonate resin (D) include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, carbonic acid diphenyl ester, etc.

These may be used alone or in combination of two or more.

The resin composition of the present invention contains the aforementioned polyester polyurethane polyol (A), the aforementioned polyester polyol (B), the aforementioned hydroxyl-containing epoxy resin (C) and the aforementioned hydroxyl-containing polycarbonate resin (D) in the following proportions , the aforementioned hydroxyl-containing epoxy resin (C) is in the range of 5 to 20 mass parts and the aforementioned hydroxyl-containing polycarbonate is The ester resin (D) is in the range of 5 to 20 parts by mass, thereby forming a resin composition that is excellent in adhesiveness to various substrates and can maintain high substrate adhesiveness even under hot and humid conditions.

In addition, the compounding ratio of the aforementioned polyester polyurethane polyol (A) and the aforementioned polyester polyol (B) in the resin composition of the present invention is preferably in the range of 10:50 to 90:10 by mass ratio, and particularly preferably It is in the range of 20:80 to 50:50.

The resin composition of the present invention preferably uses the aforementioned polyisocyanate (E) as a curing agent component. As this polyisocyanate (E), the various polyisocyanates listed as said polyisocyanate (G) are mentioned, for example. These polyisocyanates (E) may be used alone or in combination of two or more.

Among these polyisocyanates (E), the above-mentioned aliphatic diisocyanate compounds are preferable because yellowing of the adhesive coating film is less likely to occur. Moreover, the said uric acid ester type polyisocyanate compound is preferable from the point which is excellent in the base-material adhesiveness under the heat-and-moisture condition.

The resin composition of the present invention contains the aforementioned polyester polyurethane polyol (A), the aforementioned polyester polyol (B), the aforementioned hydroxyl-containing epoxy resin (C), the aforementioned hydroxyl-containing polycarbonate resin (D) and polyisocyanate ( E) as an essential ingredient. In the present invention, the amount of hydroxyl groups contained in the aforementioned polyester polyurethane polyol (A), the aforementioned polyester polyol (B), the aforementioned hydroxyl-containing epoxy resin (C) and the aforementioned hydroxyl-containing polycarbonate resin (D) The ratio [OH]/[NCO] of the total number of moles [OH] to the number of moles [NCO] of isocyanate groups contained in the polyisocyanate compound (E) is in the range of 1/1 to 1/2, more preferably 1 /1.05 to 1/1.5, thereby becoming a resin composition excellent in curability.

The resin composition of the present invention may contain various solvents. The aforementioned solvents include, for example, ketone compounds such as acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone, cyclic ether compounds such as tetrahydrofuran (THF), and dioxolane, methyl acetate, ethyl acetate, and the like. Esters, ester compounds such as butyl acetate, aromatic compounds such as toluene and xylene, alcohols such as carbitol, cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether compounds, etc. These compounds may be used alone or in combination of two or more.

The resin composition of the present invention may further contain various additives such as ultraviolet absorbers, antioxidants, silicon additives, fluorine additives, rheology control agents, defoamers, antistatic agents, and antifogging agents.

The resin composition of the present invention can be suitably used as a two-component type lamination adhesive for bonding various plastic films.

The above-mentioned various plastic films, for example, include polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polystyrene, polyester, polyolefin, epoxy resin, melamine resin, triacetyl Films made of cellulose-based resins, polyvinyl alcohol, ABS resins, norbornene-based resins, cyclic olefin-based resins, polyimide resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, etc. The two-component adhesive for lamination of the present invention exhibits high adhesion even to films made of polyvinyl fluoride resin and polyvinylidene fluoride resin, which are particularly difficult to bond among the various films described above.

When bonding the aforementioned various films to each other, the amount of the two-component lamination adhesive of the present invention is preferably in the range of 2 to 10 g/m ² .

A laminated film obtained by bonding a plurality of films using the two-component laminating adhesive of the present invention is characterized in that it has high adhesiveness even under hot and humid conditions, and the films are not easily peeled off.

Therefore, the two-component lamination adhesive of the present invention can be suitably used for lamination films used in harsh environments such as outdoors. Examples of such applications include the production of back sheets for solar cells. adhesives, etc.

Example

Hereinafter, specific synthesis examples and examples are given to describe the present invention in more detail, but the present invention is not limited to these examples. In addition, in the following examples, "parts" and "%" represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

It should be noted that, in the examples of the present application, the number average molecular weight (Mn) and weight average molecular weight (Mw) were measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation

Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation + TSK-GEL SuperHZM-M manufactured by Tosoh Corporation × 4

Detector: RI (differential refractometer)

Data processing: Multi station GPC-8020 model II manufactured by Tosoh Corporation

Determination conditions: column temperature 40°C

Solvent Tetrahydrofuran

      Flow rate 0.35ml/min

Standard : Monodisperse polystyrene

Sample : A substance obtained by filtering a tetrahydrofuran solution of 0.2% by mass in terms of resin solid content with a microfilter (100 μl)

(Synthesis Example 1-1) [Synthesis of Polyester Polyurethane Polyol (A1)]

Put 1131 parts of neopentyl glycol, 737 parts of isophthalic acid, 342 parts of phthalic anhydride, 534 parts of sebacic acid, 20 parts of trimellitic anhydride and organic titanium compound into a flask equipped with a stirring bar, a temperature sensor and a rectifying tube 1.3 parts, while passing dry nitrogen gas into the flask and stirring, it was heated to 230-250°C to carry out esterification reaction. When the acid value was 1.0 mgKOH/g or less, the reaction was stopped, and after cooling to 100° C., it was diluted with ethyl acetate until the solid content was 80%. Next, 124 parts of an isocyanurate-modified body of hexamethylene diisocyanate (SUMIDUR N-3300; manufactured by Sumitomo Bayer Urethane Co., Ltd.) and 25 parts of hexamethylene diisocyanate were put into the flask. Pass through dry nitrogen and stir, while heating to 70-80°C to carry out urethanization reaction. The reaction was stopped when the isocyanate content was 0.3% or less, and a polyester polyurethane polyol having a number average molecular weight of 5,700, a weight average molecular weight of 35,000, and a hydroxyl value of 10 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyurethane polyol (A1).

(Synthesis Example 1-2) [Synthesis of Polyester Polyurethane Polyol (A2)]

Put 1155 parts of neopentyl glycol, 755 parts of isophthalic acid, 325 parts of phthalic anhydride, 507 parts of sebacic acid, 20 parts of trimellitic anhydride and organic titanium compound into the flask with stirring rod, temperature sensor and rectification tube 1.3 parts, while passing dry nitrogen gas into the flask and stirring, it was heated to 230-250°C to carry out esterification reaction. When the acid value was 1.0 mgKOH/g or less, the reaction was stopped, and after cooling to 100° C., it was diluted with ethyl acetate until the solid content was 80%. Next, 247 parts of an isocyanurate-modified body of hexamethylene diisocyanate (SUMIDUR N-3300; manufactured by Sumitomo Bayer Urethane Co., Ltd.) and 40 parts of hexamethylene diisocyanate were put into the flask. Pass through dry nitrogen and stir, while heating to 70-80°C to carry out urethanization reaction. The reaction was stopped when the isocyanate content was 0.3% or less, and a polyester polyurethane polyol having a number average molecular weight of 7,800, a weight average molecular weight of 88,000, and a hydroxyl value of 12 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyurethane polyol (A2).

(Synthesis Example 1-3) [Synthesis of Polyester Polyurethane Polyol (A3)]

Put 1144 parts of neopentyl glycol, 753 parts of isophthalic acid, 464 parts of phthalic anhydride, 373 parts of sebacic acid, 19 parts of trimellitic anhydride and organic titanium compound into the flask with stirring rod, temperature sensor and rectification tube 1.3 parts, while passing dry nitrogen gas into the flask and stirring, it was heated to 230-250°C to carry out esterification reaction. When the acid value was 1.0 mgKOH/g or less, the reaction was stopped, and after cooling to 100° C., it was diluted with ethyl acetate until the solid content was 80%. Next, 132 parts of an isocyanurate-modified body of hexamethylene diisocyanate (SUMIDUR N-3300; manufactured by Sumitomo Bayer Urethane Co., Ltd.) and 13 parts of hexamethylene diisocyanate were put into the flask. Pass through dry nitrogen and stir, while heating to 70-80°C to carry out urethanization reaction. The reaction was stopped when the isocyanate content was 0.3% or less, and a polyester polyurethane polyol having a number average molecular weight of 5,000, a weight average molecular weight of 51,000, and a hydroxyl value of 17 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyurethane polyol (A3).

(Synthesis Example 1-4) [Synthesis of Polyester Polyurethane Polyol (A4)]

941 parts of neopentyl glycol, 201 parts of 1,6-hexanediol, 757 parts of isophthalic acid, 301 parts of phthalic anhydride, adipic acid 68 parts, 470 parts of sebacic acid, 19 parts of trimellitic anhydride and 1.3 parts of organotitanium compound were heated to 230-250°C to carry out esterification reaction while passing dry nitrogen gas into the flask and stirring. When the acid value was 1.0 mgKOH/g or less, the reaction was stopped, and after cooling to 100° C., it was diluted with ethyl acetate until the solid content was 80%. Next, 132 parts of hexamethylene diisocyanate modified isocyanurate (SUMIDUR N-3300; manufactured by SumitomoBayer Urethane Co., Ltd.) and 13 parts of hexamethylene diisocyanate were introduced into the flask Add dry nitrogen and stir while heating to 70-80°C to carry out urethanization reaction. The reaction was stopped when the isocyanate content was 0.3% or less, and a polyester polyurethane polyol having a number average molecular weight of 5,500, a weight average molecular weight of 32,000, and a hydroxyl value of 11 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyurethane polyol (A4).

(Synthesis Example 2-1) [Synthesis of Polyester Polyol (B1)]

Put 828 parts of neopentyl glycol, 588 parts of isophthalic acid, 274 parts of phthalic anhydride, 407 parts of sebacic acid, 15 parts of trimellitic anhydride and organic titanium compound into the flask with stirring rod, temperature sensor and rectification tube 1.0 parts, while passing dry nitrogen gas into the flask and stirring, it was heated to 230-250°C to carry out esterification reaction. The reaction was stopped when the acid value was 1.0 mgKOH/g or less, and a polyester polyol having a number average molecular weight of 6,700, a weight average molecular weight of 22,000, and a hydroxyl value of 12 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyol (B1).

(Synthesis Example 2-2) [Synthesis of Polyester Polyol (B2)]

Put 1114 parts of neopentyl glycol, 717 parts of isophthalic acid, 456 parts of phthalic anhydride, 407 parts of sebacic acid, 19 parts of trimellitic anhydride and organic titanium compound into the flask with stirring rod, temperature sensor and rectification tube 1.0 parts, while passing dry nitrogen gas into the flask and stirring, it was heated to 230-250°C to carry out esterification reaction. The reaction was stopped when the acid value was 1.0 mgKOH/g or less, and a polyester polyol having a number average molecular weight of 6,200, a weight average molecular weight of 23,000, and a hydroxyl value of 15 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyol (B2).

(Synthesis Example 2-3) [Synthesis of Polyester Polyol (B3)]

Put 985 parts of neopentyl glycol, 70 parts of 1,6-hexanediol, 600 parts of isophthalic acid, 144 parts of terephthalic acid, and 349 parts of acid anhydride, 25 parts of adipic acid, 514 parts of sebacic acid, 19 parts of trimellitic anhydride and 1.3 parts of organic titanium compound were heated to 230-250°C for esterification reaction while feeding dry nitrogen into the flask and stirring. The reaction was terminated when the acid value was 1.0 mgKOH/g or less, and a polyester polyol having a number average molecular weight of 6,000, a weight average molecular weight of 20,000, and a hydroxyl value of 13 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyol (B3).

(Comparative Synthesis Example 1-1) [Synthesis of Polyester Polyurethane Polyol (a1)]

Put 1130 parts of neopentyl glycol, 759 parts of isophthalic acid, 342 parts of phthalic anhydride, 534 parts of sebacic acid and 1.2 parts of organotitanium compound into the flask with stirring bar, temperature sensor and rectification tube. Pass dry nitrogen into the flask and stir, while heating to 230-250°C to carry out esterification reaction. When the acid value was 1.0 mgKOH/g or less, the reaction was stopped, and after cooling to 100° C., it was diluted with ethyl acetate until the solid content was 80%. Next, 108 parts of hexamethylene diisocyanate was injected|thrown-in, and it heated at 70-80 degreeC, blowing dry nitrogen gas into a flask, and stirring, and performed urethanization reaction. The reaction was stopped when the isocyanate content was 0.3% or less, and a polyester polyurethane polyol having a number average molecular weight of 10,000, a weight average molecular weight of 22,000, and a hydroxyl value of 9 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyurethane polyol (a1).

(Comparative Synthesis Example 1-2) [Synthesis of Polyester Polyurethane Polyol (a2)]

Put 1210 parts of neopentyl glycol, 679 parts of isophthalic acid, 346 parts of phthalic anhydride, 539 parts of adipic acid, 20 parts of trimellitic anhydride and organic titanium compound into the flask with stirring rod, temperature sensor and rectification tube 1.2 parts, while passing dry nitrogen into the flask and stirring, heated to 230-250°C to carry out esterification reaction. When the acid value was 1.0 mgKOH/g or less, the reaction was stopped, and after cooling to 100° C., it was diluted with ethyl acetate until the solid content was 80%. Next, 132 parts of an isocyanurate-modified product of hexamethylene diisocyanate (SUMIDUR N-3300; manufactured by Sumitomo Bayer Urethane Co., Ltd.) and 25 parts of hexamethylene diisocyanate were put into the flask. Pass through dry nitrogen and stir, while heating to 70-80°C to carry out urethanization reaction. The reaction was stopped when the isocyanate content was 0.3% or less, and a polyester polyurethane polyol having a number average molecular weight of 5,500, a weight average molecular weight of 32,000, and a hydroxyl value of 12 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyurethane polyol (a2).

(Comparative Synthesis Example 2-1) [Synthesis of Polyester Polyol (b1)]

Put 1088 parts of neopentyl glycol, 727 parts of isophthalic acid, 336 parts of phthalic anhydride, 524 parts of sebacic acid, 19 parts of trimellitic anhydride and organic titanium compound into the flask with stirring rod, temperature sensor and rectification tube 1.2 parts, while passing dry nitrogen into the flask and stirring, heated to 230-250°C to carry out esterification reaction. The reaction was terminated when the acid value was 1.0 mgKOH/g or less, and a polyester polyol having a number average molecular weight of 2,300, a weight average molecular weight of 5,000, and a hydroxyl value of 50 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyol (b1).

(Comparative Synthesis Example 2-2) [Synthesis of Polyester Polyol (b1)]

Put 1105 parts of neopentyl glycol, 898 parts of isophthalic acid, 421 parts of phthalic anhydride, 272 parts of adipic acid, 19 parts of trimellitic anhydride and organic titanium compound into the flask with stirring rod, temperature sensor and rectification tube 1.2 parts, while passing dry nitrogen into the flask and stirring, heated to 230-250°C to carry out esterification reaction. The reaction was terminated when the acid value was 1.0 mgKOH/g or less, and a polyester polyol having a number average molecular weight of 7,200, a weight average molecular weight of 21,000, and a hydroxyl value of 15 was obtained. This was diluted with ethyl acetate to obtain a resin solution having a solid content of 62% as polyester polyol (b2).

The epoxy resins (C) used in Examples and Comparative Examples of the present invention are shown below.

Epoxy resin (C1): Bisphenol A type epoxy resin with a number average molecular weight (Mn) of 470 and an epoxy equivalent of 245 g/eq ("Epiclon 860" manufactured by DIC Corporation) Epoxy resin (C2): number Bisphenol A type epoxy resin with an average molecular weight (Mn) of 900 and an epoxy equivalent of 475 g/eq ("JER1001" manufactured by Mitsubishi Chemical Corporation)

The polycarbonate resin (D) used in the Example of this invention and a comparative example is shown below.

・Polycarbonate polyol (D1): polycarbonate diol having a number average molecular weight (Mn) of 1000 and a hydroxyl value of 10 mgKOH/g (“DURANOL T5651” manufactured by Asahi Kasei Co., Ltd.)

The polyisocyanates (E) used in Examples and Comparative Examples of the present invention are shown below

・Polyisocyanate (E1): an isocyanurate-modified product of hexamethylene diisocyanate (“SUMIDURN3300” manufactured by SumitomoBayer Urethane Co., Ltd.)

(Example 1)

With 10 parts of polyester polyurethane polyol (A1) solutions obtained in the aforementioned manufacture example 1-1, 90 parts of the polyester polyol (B1) solutions gained in the aforementioned manufacture example 2-1, 10 parts of the aforementioned epoxy resins (C1) 10 parts, 10 parts of the aforementioned polycarbonate polyol (C1) and 10 parts of the aforementioned polyisocyanate (D1) were mixed to obtain a resin composition, and an evaluation sample was produced in the following manner, and evaluated by the method shown below. The results are shown in Table 1.

(Preparation of evaluation samples)

A 125 μm thick PET film ("X10S" manufactured by Toray Co., Ltd.) was used as a substrate, and the mass of the solid content of the resin composition obtained in the above Example 1 after drying with a solvent was in the range of 5 to 6 g/ ^m2. Then, a fluororesin film ("AFLEX 25PW" manufactured by Asahi Glass Co., Ltd.) with a thickness of 25 μm was laminated to obtain a laminated film. This was aged at 50° C. for 72 hours to obtain an evaluation sample.

(Evaluation 1): Appearance The laminated appearance was visually evaluated from the fluororesin film side of the evaluation sample produced by the above method.

○: The film surface is smooth △: There are a few arc craters on the film surface ×: There are many arc craters (depressions) on the film surface

(Evaluation 2): Measurement of adhesive force under moist heat conditions For the evaluation sample prepared by the aforementioned method, using a tensile tester ("AGS500NG" manufactured by SHIMADZU Co., Ltd.), at a peeling speed of 300mm/min, a strength N/ A T-peel test was performed under the condition of 15 mm, and the strength was evaluated as adhesive force. The initial adhesive force of the evaluation sample, and the adhesive force of the sample after exposure to 121 degreeC and 100% humidity environment for 25 hours, 50 hours, and 75 hours were measured.

(Evaluation 3): Evaluation of moisture and heat resistance The initial adhesive force of the evaluation sample measured in the aforementioned evaluation 2 was compared with the adhesive force of the sample after exposure for 75 hours at 121° C. and a humidity of 100% environment, and the post-exposure The sample whose adhesive force is 60% or more of the initial adhesive force was evaluated as ◯, the sample which was 40% or more and less than 60% was evaluated as △, and the sample which was less than 40% was evaluated as ×.

(Examples 2-14)

Except having changed the formulation of the resin composition as shown in Tables 1-2, it carried out similarly to Example 1, and produced the evaluation sample, and evaluated it. The evaluation results are shown in Tables 1-2.

(Comparative Examples 1-10) Except having changed the formulation of the resin composition as shown in Tables 3-4, it carried out similarly to Example 1, produced the evaluation sample, and evaluated it. The evaluation results are shown in Tables 3-4.

[Table 1]

[Table 2]

[table 3]

[Table 4]

Claims (16)

1. A resin composition, characterized in that, it takes the following components as essential components: (1) A polyester polyurethane polyol (A) having a branched structure in the molecule, a weight average molecular weight (Mw) in the range of 10,000 to 100,000, and a molecular weight distribution (Mw/Mn) of 5.0 or more, and (2) A polyester polyol (B) having a branched structure in a molecule, a weight average molecular weight (Mw) in the range of 10,000 to 50,000, and a molecular weight distribution (Mw/Mn) of less than 5.0. 2. The resin composition according to claim 1, wherein, the polyester polyurethane polyol (A) is polybasic acid (E), polyol (F) and polyisocyanate compound (G2) with more than 3 functions as Necessary components are reacted and obtained. 3. The resin composition according to claim 1, wherein the polyester polyurethane polyol (A) is a polyester polyurethane polyol obtained by reacting a polyisocyanate (G) as an essential component, and the polyisocyanate (G) The diisocyanate compound (G1) and the trifunctional or more polyisocyanate compound (G2) are contained in the range of 50/50-5/95 in mass ratio (G1)/(G2) of both. 4. The resin composition according to claim 3, wherein the range of the hydroxyl value of the polyester polyurethane polyol (A) is 5-30 mgKOH/g. 5. The resin composition according to claim 2, wherein, it is necessary that the polybasic acid (E) contains 10 to 30 mole % of an aliphatic dibasic acid with 8 or more carbon atoms and an aromatic dibasic acid The dibasic acid component is 50 to 90 mol% of acid, and the polyol (F) contains 40 to 100 mol% of an aliphatic polyhydric alcohol having 5 or more carbon atoms. 6 . The resin composition according to claim 1 , wherein the polyester polyurethane polyol (A) is obtained by reacting a trifunctional or higher polyisocyanate compound (G2) as an essential component. 7. The resin composition according to claim 1, wherein, the polyester polyol (B) is composed of 10 to 30 mole % of an aliphatic dibasic acid containing 8 or more carbon atoms and 50% of an aromatic dibasic acid. A polyester polyol formed of a dibasic acid component of ˜90 mol % and an aliphatic polyol having 5 or more carbon atoms in an amount of 40 mol % to 100 mol %. 8. The resin composition according to claim 6, wherein the polyester polyol (B) has a hydroxyl value in the range of 5 to 30 mgKOH/g. 9. The resin composition according to claim 1, further comprising (3) a number average molecular weight (Mn) of 300 to 5,000 in addition to the component (A) and the component (B). Hydroxy epoxy resin (C). 10. The resin composition according to claim 9, further comprising (4) a number average molecular weight (Mn) of The hydroxyl group containing polycarbonate resin (D) in the range of 300-3000. 11. The resin composition according to claim 9 or 10, further comprising (5) polyisocyanate (E) as a curing agent in addition to the component (A) and the component (B). 12. The resin composition according to claim 11, wherein, the polyester polyurethane polyol (A), the polyester polyol (B), the epoxy resin (C) and the polycarbonate The ratio [OH]/[NCO] of the total number of moles of hydroxyl groups [OH] contained in the resin (D) to the number of moles of isocyanate groups [NCO] contained in the polyisocyanate compound (E) is 1/1 ~1/2 range. 13. The resin composition according to claim 10, wherein, with respect to 100 parts by mass of the total of the polyester polyurethane polyol (A) and the polyester polyol (B), the The said epoxy resin (C) is included in the range, and the said polycarbonate resin (D) is contained in the range of 5-20 mass parts. 14. A two-component adhesive for lamination comprising the resin composition according to claim 11. 15. A laminated film comprising at least one film selected from the group consisting of a polyester film, a fluororesin film, a polyolefin film, and a metal foil, and an adhesive formed by the adhesive according to claim 14. layer. 16. A solar cell backsheet having an adhesive layer formed of the adhesive according to claim 14.