JP2011001484A - Adhesive composition for laminated sheet and laminated material comprised of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive that does not foam even when used for compounding substrates of low gas permeability for laminating composite sheets, is excellent in appearance, and can maintain adhesive strength over long period of time by controlling deterioration of adhesive strength with age when exposed at outdoor, and to provide a laminated sheet employing the adhesive composition.SOLUTION: The adhesive composition for laminated sheets consists of a polyol (A), that has averagely 1.5-3.5 primary hydroxy groups in one molecule, and whose number average molecular weight is 5,000-50,000, and a polyisocyanate (B) having averagely 4-7 isocyanate groups in one molecule, and number of the isocyanate group of the polyisocyanate (B) having averagely 4-7 isocyanate groups in one molecule is 0.1-0.7 mole against one mole of the total isocyanate groups contained in the composition.

Description

  The present invention relates to an adhesive composition for laminated sheets used for plastic films, metal foils and the like.

  In recent years, aluminum as a multilayer (composite) sheet used for outdoor industrial applications, for example, barrier materials, roofing materials, solar cell panel materials, window materials, outdoor flooring materials, lighting protection materials, automobile members, signboards, stickers, etc. , Copper or steel sheet metal foil, metal plate, or metal vapor deposition film and polypropylene, polyvinyl chloride, polyester, fluororesin, acrylic resin, or other plastic film were laminated to form a laminated film Things have been used. As an adhesive composition for bonding a metal foil, a metal plate, or a metal vapor-deposited film, and a plastic film in these multilayer films, a polyepoxy adhesive composition or a polyurethane adhesive composition is known. ing.

  Japanese Patent Application Laid-Open No. 10-218978 (Patent Document 1) discloses a polyester resin in consideration of balance, which can give excellent initial cohesive force and adhesive force, and a polyurethane resin adhesive composition using the polyester resin. Has been.

  Japanese Patent Laid-Open No. 06-116542 (Patent Document 2) discloses a polyurethane adhesive composition having excellent hot water resistance during retort sterilization in food packaging.

  JP-A-2008-4691 (Patent Document 3) discloses that a polyurethane adhesive composition having hydrolysis resistance is used in a solar cell back surface sealing sheet.

  Furthermore, Japanese Unexamined Patent Application Publication No. 2007-136911 (Patent Document 4) discloses a solar cell back surface sealing sheet provided with an adhesion improving layer made of a polyester resin or a polyester polyurethane resin.

On the other hand, efforts to combat global warming have become urgent in recent years, and the development and provision of materials with long-term durability will lead to savings and become environmental protection measures.

  However, in the urethane-based adhesive of the above prior art, a side reaction due to the reaction between isocyanate and water occurs, and when a laminated sheet is formed, carbon dioxide gas is generated. For example, an aluminum foil, a vapor deposition film, or a thick polyester ( When a PET film (for example, a PET film having a thickness of 250 μm) is bonded to each other, carbon dioxide gas bubbles are generated in the adhesive because there is no escape of carbon dioxide gas, and the performance and appearance are significantly deteriorated. In addition, the adhesive strength over time decreases due to hydrolysis during outdoor exposure, and strong adhesive strength cannot be maintained over a long period of time, resulting in poor appearance and delamination, resulting in reduced barrier properties against water vapor and the like. As a result, the function of the multilayer film is lost. In addition, with conventional adhesives, a process requiring 60 ° C. or more and 3 days or more is required to obtain long-term durability for aging after lamination.

JP-A-10-218978 Japanese Patent Laid-Open No. 06-116542 JP 2008-4691 A JP 2007-136911 A

  The present invention provides an adhesive composition capable of preventing the generation of bubbles during lamination, suppressing the decrease in adhesive strength over time during outdoor exposure, and maintaining the adhesive strength over a long period of time, and shortening the aging time. And a laminate using the adhesive composition.

  The problem is that the polyol (A) having 1.5 to 3.5 primary hydroxyl groups on average in one molecule and having a number average molecular weight of 5,000 to 50,000, and in one molecule It is the adhesive composition for laminated sheets containing the polyisocyanate (B) having an average of 4 to 7 isocyanate groups in the polyisocyanate (B) having an average of 4 to 7 isocyanate groups in one molecule. It is solved by the adhesive composition for laminated sheets, wherein the isocyanate group is 0.1 to 0.7 mol with respect to 1 mol of all isocyanate groups in the composition.

  The present invention further relates to the adhesive composition for laminated sheets, characterized by containing 0.1 to 5% by weight of the silane coupling agent (C) based on the polyol (A).

  Further, the present invention further comprises a resin composition (D) containing an epoxy resin and / or a carbodiimide resin based on the polyol (A), and the adhesive composition for laminated sheets described above. Related to things.

  The present invention also relates to the adhesive composition for laminated sheets, wherein the resin composition (D) is an epoxy resin having a number average molecular weight of 300 to 5,000.

 The present invention also relates to the adhesive composition for laminated sheets, wherein the polyisocyanate (B) is hexamethylene diisocyanate or a polyisocyanate derived from hexamethylene diisocyanate and isophorone diisocyanate.

 The present invention also relates to the adhesive composition for laminated sheets, wherein the polyisocyanate other than polyisocyanate (B) is a trimethylolpropane adduct of isophorone diisocyanate and / or a nurate of isophorone diisocyanate.

 Moreover, this invention relates to the laminated body using the adhesive agent for laminated sheets in any one of the said.

  By using the adhesive composition for laminated sheets of the present invention as an adhesive for laminated sheets, it is possible to prevent the generation of air bubbles during lamination and to suppress a decrease in adhesive strength over time during outdoor exposure, and to adhere over a long period of time. By providing an adhesive capable of maintaining the strength, for example, the aging conditions that conventionally required 60 ° C.-3 days or more can be made within 40 ° C.-3 days.

  Since the polyol (A) has an average of 1.5 to 3.5 primary hydroxyl groups having high reactivity with isocyanate groups in one molecule, the polyol (A) and the water contained in the composition or air from the reaction of an isocyanate group of the isocyanate, the reaction of the primary hydroxyl group and Isoshineto groups of the polyisocyanate polyol (a) can be preferentially further polyisocyanates having an average 4-7 isocyanate groups per molecule Since the isocyanate group of (B) is 0.1 to 0.7 mol with respect to 1 mol of all isocyanate groups in the composition, the crosslinking can be accelerated even if the curing speed is the same, so that foaming is suppressed. In addition, by suppressing the swelling of the resin at a high temperature, it is possible to suppress the intrusion of moisture into the resin and to improve the moisture and heat resistance of the cured adhesive film. Moreover, aging time can also be shortened because bridge | crosslinking is quick.

  The adhesive composition for laminated sheets of the present invention has a polyol having an average of 1.5 to 3.5 primary hydroxyl groups in one molecule and a number average molecular weight of 5,000 to 50,000. A) and an adhesive composition for a laminated sheet containing polyisocyanate (B) having an average of 4 to 7 isocyanate groups in one molecule, and an average of 4 to 7 isocyanate groups in one molecule The isocyanate group of the polyisocyanate (B) having the above is 0.1 to 0.7 mol with respect to 1 mol of all isocyanate groups in the composition.

<Polyol (A)>
Although polyol (A) is not limited to the following, for example, polyester polyol, polyurethane polyol, polyether polyol, polycarbonate polyol, polyester polyurethane polyol, polyether polyurethane polyol, polycarbonate polyurethane polyol, or two types of the above polyols The above mixture etc. are mentioned. From the viewpoints of adhesive strength, durability, and workability, polyester polyol and / or polyester polyurethane polyol are preferable.

  The number average molecular weight of the polyol (A) is 5,000 to 50,000, preferably 8,000 to 30,000. If it is 8,000 or less, the initial cohesive force may be insufficient, and tunneling may occur during lamination. If it is 30,000 or more, the initial cohesive force is sufficient, but the coating viscosity becomes high and the coating method may be limited. When it is 5,000 or less, the initial cohesive force is lowered. Moreover, when it is 50,000 or more, the solubility of a resin, a viscosity, and the applicability | paintability (handleability) of an adhesive agent will fall.

  The average number of primary hydroxyl groups in the polyol (A) is 1.5 to 3.5, preferably 2.0 to 3.0, per molecule. When it is 2 or less, foam suppression may be weakened by the base material, and when it is 3 or more, the pot life may be shortened and workability may be deteriorated. If it is 1.5 or less, crosslinking is difficult to proceed, and foam suppression is not sufficient. If the number is four or more, there is a problem that gelation is likely to occur during synthesis, and synthesis is difficult.

  Polyol (A) can be synthesized with polyester polyol by esterification reaction of polyhydric alcohol and polybasic acid. Furthermore, it can be synthesized as a polyester polyurethane polyol by extending the chain with polyisocyanate.

  By adjusting the ratio of dihydric alcohol and trihydric alcohol used as the polyhydric alcohol, the number of primary hydroxyl groups can be adjusted on an average per molecule.

  Although it does not specifically limit as a polyhydric alcohol, For example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-butanediol, 1, Examples include dihydric alcohols such as 4-cyclohexanedimethanol, 1,9-nanonediol, or 3-methyl-1,5-pentanediol, trihydric alcohols such as glycerin, trimethylolpropane, and the like. Monovalent alcohols such as stearyl alcohol may also be used. Two or more kinds of these alcohols can be used in any combination.

  The polybasic acid is not particularly limited. As the aromatic acid, an aromatic dibasic acid such as terephthalic acid, isophthalic acid, phthalic acid, or naphthalenedicarboxylic acid is mainly used, but benzoic acid, p- A monobasic acid such as tertiary butylbenzoic acid or an aromatic tribase such as trimellitic anhydride can also be used. Aliphatic polybasic acids include aliphatic dibasic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, hexahydrophthalic acid, tetrahydrophthalic acid, malee, etc. A basic acid etc. are mentioned and 1 or more types can be used in arbitrary combinations. Although tetrabasic or higher polybasic acids such as pyromellitic acid can be used, it is difficult to adjust to a preferable molecular weight and viscosity. The dibasic acid can be used for synthesis in whole or in part as its anhydride or dimethyl ester (transesterification reaction).

  In consideration of molecular weight, average number of primary hydroxyl groups per molecule, adhesion and durability, the molar ratio of dihydric alcohol, trihydric alcohol, aromatic dibasic acid, aromatic tribasic acid and aliphatic dibasic acid The polyol (A) can be synthesized by adjusting. It is desirable to make the polyhydric alcohol excessive so that the terminal of the polyol (A) chain becomes a primary hydroxyl group (so that the terminal is not carboxyl).

  A polyester polyurethane polyol can also be obtained by reacting the polyester polyol with a polyisocyanate (described later).

  In the esterification or urethanization, a known reaction catalyst can be used. Further, the synthesized polyol (A) can be used as a polyol (A) resin solution by dissolving in an arbitrary organic solvent (described later).

  An arbitrary polyol can be contained in addition to the polyol (A) as long as the effects of the present invention are not impaired, but the polyol (A) is preferably 90% by weight or more based on the total polyol. If it is less than 90% by weight, crosslinking is difficult to proceed, and foam suppression is not sufficient.

<Polyisocyanate>
Polyisocyanates are, but are not limited to, compounds derived from the well-known diisocyanates. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, bis (4-isocyanatocyclohexyl) methane, or water Diisocyanates such as added diphenylmethane diisocyanate, or their nurate, trimethylolpropane adduct, biuret type, prepolymer having isocyanate residues (low polymer obtained from diisocyanate and polyol), uretdione having isocyanate residues , Allophanate, or a complex thereof, and the like can be used alone or in combination of two or more. Especially, since it is used also for an outdoor use, it is preferable to use an aliphatic or alicyclic isocyanate, or its derivative (s) in order to reduce yellowing with time.

  The polyisocyanate (B) is a polyisocyanate having an average of 4 to 7 isocyanate groups in one molecule, and is an allophanate type, nurate type derivative derived from the above diisocyanate, or a complex thereof. .

  The polyisocyanate (B) is not particularly limited as a commercially available product, but Duranate MHG-80B, Duranate MFA-75 (manufactured by Asahi Kasei Chemical Co., Ltd., average functional group number 5 to 6), or Coronate 2785 (manufactured by Nippon Polyurethane Co., Ltd.) And an average functional group number of 4 to 5).

  The number of isocyanate groups in the polyisocyanate (B) is on average 4 to 7, preferably 5 to 6 in one molecule. When the amount is less than 5, when used in a small amount, the foam suppression is insufficient, and when the amount is more than 6, the pot life may be shortened. When the number is less than 4, foaming suppression is insufficient, and when the number is more than 7, the crosslink density of the adhesive is increased, and the adhesion at the time of lamination is lowered. In addition, the pot life is very short, making it difficult to use. If it is less than 4, the effect of suppressing foaming is insufficient.

In the polyisocyanate (B), the isocyanate group is 0.1 to 0.7 mol with respect to 1 mol of all isocyanate groups in the composition. More preferably, it is 0.3-0.5 mol. When it is 0.3 mol or less, the foaming suppression effect may be weak, and the heat and humidity resistance may be lowered. If it is 0.5 mol or more, the pot life may be shortened, and the heat and humidity resistance may be lowered. If it is less than 0.1 mol, the effect of suppressing foaming at the time of laminating is insufficient, and it may not be possible to shorten the long-term moist heat resistance and aging time of the adhesive. On the other hand, when the amount is more than 0.7 mol, the pot life becomes very short, the coating property is lowered, and the heat and moisture resistance is lowered.

  The polyisocyanate (B) is preferably a polyisocyanate derived from hexamethylene diisocyanate (hereinafter abbreviated as HDI) or HDI and isophorone diisocyanate (hereinafter abbreviated as IPDI). Other than HDI or IPDI, there are xylylene diisocyanate (hereinafter abbreviated as XDI) or bis (4-isocyanatocyclohexyl) methane (hereinafter abbreviated as H12MDI), but XDI is too reactive and has a pot life. H12MDI has a problem with skin irritation. Aromatic isocyanates have a problem with yellowing outdoors.

  The polyisocyanate other than polyisocyanate (B) is preferably a trimethylolpropane adduct of isophorone diisocyanate and / or a nurate of isophorone diisocyanate. Other polyisocyanates may not provide sufficient adhesive heat resistance over a long period of time.

  The polyisocyanate containing the polyisocyanate (B) is based on the total of the polyisocyanate with respect to the total of hydroxyl groups in the polyol (A) and, in some cases, other than the polyol (A). It is preferable that the isocyanate group is blended so that the equivalent ratio is 1.0 to 10.0. If it is less than 1.0, the heat-and-moisture resistance over a long period of time is insufficient, and if it is more than 10.0, the pot life may be very short and it may be difficult to use. Moreover, since the isocyanate group which did not react with a polyol reacts with water and an adhesive agent becomes hard, adhesiveness falls.

<Silane coupling agent (C)>
The adhesive composition for laminated sheets of the present invention preferably contains a silane coupling agent (C) from the viewpoint of improving the adhesive strength to a metal foil, a metal plate, a metal vapor-deposited film or the like.
Examples of the silane coupling agent (C) include, but are not limited to, vinyl silanes such as vinyl tris (β-methoxyethoxy) silane, vinylethoxysilane, and vinyltrimethoxysilane; γ- (meth) (Meth) acryloxysilanes such as acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, and γ- (meth) acryloxypropyldimethoxymethylsilane; β- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) methyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) methyltriethoxysilane Γ-glycidoxypropyltri Epoxysilanes such as toxisilane and γ-glycidoxypropyltriethoxysilane; N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N- β (aminoethyl) γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and N-phenyl-γ- Aminosilanes such as aminopropyltriethoxysilane; and thiosilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; These may be used alone or in any combination of two or more.
“(Meth) acryloxy” means “acryloxy” and / or “methacryloxy”.

  The addition amount of the silane coupling agent (C) is preferably 0.5 to 5% by weight and more preferably 1 to 3% by weight based on the polyol (A). If it is less than 0.5% by weight, the effect of improving the adhesive strength to the metal foil by adding a silane coupling agent is poor, and even if added by 5% by weight or more, further improvement in performance may not be observed.

<Resin composition (D)>
From the viewpoint of hydrolysis resistance, the adhesive composition for laminated sheets of the present invention is an epoxy resin and / or carbodiimide resin as a resin that reacts with a carboxyl group formed by hydrolysis of an ester bond in the polyol (A). It is preferable to contain the resin composition (D) containing this. These are expected to control molecular weight reduction by reacting with carboxyl groups generated by hydrolysis of ester bonds.

Examples of the epoxy resin include, but are not limited to, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol full orange glycidyl ether,
Biscresol fluorenediglycidyl ether, bisphenoxyethanol fluorenediglycidyl ether, glycerol triglycidyl ether, glycerol diglycidyl ether, polyglycerol polyglycidyl ether, 1,6-butanediol diglycidyl ether, bisphenol A diglycidyl ether, propylene oxide modified Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, epichlorohydrin modified phthalic acid, epichlorohydrin modified hexahydrophthalic acid, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, or these 2 or more types of Thing, and the like. When used as a component of a two-component adhesive, it is preferably used as a main agent together with the polyol (A).

Examples of the carbodiimide resin include carbodiimide resins obtained by polymerizing the above polyisocyanates, but aliphatic diisocyanate-based carbodiimide resins are preferable in consideration of outdoor use. When used as a two-component adhesive, the terminal isocyanate type is preferably used as a curing agent together with the polyisocyanate, and the type in which the terminal isocyanate group is sealed with a monoalcohol or the like is used together with the polyol (A). , And preferably used as a main agent. Commercially available products include Nisshinbo Co., Ltd., Carbodilite V-01, V-02, V-03, V-04, V-05, V-06, V-08, V-09, HMV-CA, 10M-SP, 1M-25P, 9010, or 9010ST etc. are mentioned.
These resins can be used alone, in combination of two or more, or in combination with other thermosetting resins or thermoplastic resins in accordance with the desired physical properties.

  The resin composition blended in the adhesive composition for laminated sheets of the present invention is preferably an epoxy resin having a number average molecular weight of 300 to 5,000 from the viewpoints of adhesive strength and heat and humidity resistance. As an epoxy resin having a number average molecular weight of 300 to 5000, for example, a commercially available product is not limited to the following, but is manufactured by Japan Epoxy Resin, Epicoat 825, 827, 828, 834, 1001, 1002, 1003, 1055. 1004, 1007, 806, 807, or 4004 series, manufactured by Adeka, Adeka Resin EP-4100, 4300, 4340, 4200, 4400, 4500, 4510, 4520, 4530, 4901, 4930, 4950, 5100, 4000, 4005, 1307, 4004, 4080, or 4092 series, or DIC Corporation, Epicron 152, 153, 1121N, 1123N, N-660, N-665, N-670, N-673, N-680, N-695, N -660, -672, N-662, N-655, N-673,850,830,4032,7120,7015, or 7200 series, and the like.

The blending amount of the resin composition (D) is preferably 50% by weight or less based on the oleol (A) from the viewpoints of adhesive strength and heat and humidity resistance. More preferably, it is 20 to 40% by weight.
If it is 20% by weight or less, the effect of improving the heat and moisture resistance is not sufficient, and if it is 50% by weight or more, the adhesive becomes hard and the adhesiveness is lowered.

  The adhesive composition for laminated sheets of the present invention may be a so-called two-liquid mixed type adhesive in which the main agent and the curing agent are mixed at the time of use, or one liquid in which the main agent and the curing agent are mixed in advance. It may be a type of adhesive. Furthermore, the type which mixes a several main ingredient and / or several hardening | curing agent at the time of use may be sufficient. Usually, the main agent contains polyol (A), and if necessary, other polyol, silane coupling agent (C), resin composition (D), organic solvent, and other additives, and the curing agent is polyisocyanate. (B), other polyisocyanates, and if necessary, an organic solvent and other additives.

  As other additives, in order to improve metal adhesion, phosphoric acid compounds such as phosphoric acid, metaphosphoric acid, pyrophosphoric acid, esters of phosphorous acid, and the like can be added.

  In addition, additives known for adhesives can be added to the main agent, and for example, a reaction accelerator can be used. For example, metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dimaleate; 1,8-diaza-bicyclo (5,4,0) undecene-7, 1,5-diazabicyclo (4,3 , 0) Nonene-5,6-dibutylamino-1,8-diazabicyclo (5,4,0) undecene-7 and other tertiary amines; reactive tertiary amines such as triethanolamine, and the like. One or more kinds of reaction accelerators selected from the group can be used.

  For the purpose of improving the appearance of the laminate, a known leveling agent or antifoaming agent can be added to the main agent.

  Examples of leveling agents include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl group-containing polydimethylsiloxane, polyetherester-modified hydroxyl group-containing polydimethylsiloxane, and acrylic copolymers. , Methacrylic copolymers, polyether-modified polymethylalkylsiloxanes, acrylic acid alkyl ester copolymers, methacrylic acid alkyl ester copolymers, lecithin, or mixtures thereof.

  Examples of the antifoaming agent include known resins such as silicone resins, silicone solutions, copolymers of alkyl vinyl ethers, alkyl acrylates and alkyl methacrylates, or mixtures thereof.

  As the curing agent, in addition to the polyisocyanate (B), a known oxazoline compound such as 2,5-dimethyl-2-oxazoline or 2,2 is optionally added within the range that does not impair the effects of the present invention. -(1,4-Butylene) -bis (2-oxazoline) or a hydrazide compound such as isophthalic acid dihydrazide, sebacic acid dihydrazide, or adipic acid dihydrazide.

  Moreover, the adhesive composition for laminated sheets of this invention can contain a well-known organic solvent, and can be used as an organic solvent solution. Examples of the organic solvent include, but are not limited to, ester solvents such as ethyl acetate or butyl acetate, or ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone. Two or more kinds can be mixed and used.

In order to produce a multilayer film using the adhesive according to the present invention, a conventionally used method can be employed. For example, an adhesive is applied to one side of one laminate base material with a comma coater or a dry laminator, and after the solvent is stripped off, it is bonded to the other laminate base material and cured at room temperature or under heating. . Amount of adhesive applied to the laminate substrate surface is preferably about 1 to 50 g / m ^2. As the laminate base material, an arbitrary base material can be selected in any number depending on the application, and when a multilayer structure of three or more layers is used, all or a part of each layer is bonded. The adhesive according to the invention can be used.

  Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, “part” means “part by weight”, “%” means “% by weight”, “hydroxyl value” means KOH mg / g, and “oxidation” means KOH mg / g.

<Polyol A>
(Terminal primary hydroxyl group is bifunctional, number average molecular weight 10,000 polyester polyol)
A reactor was charged with 31.5 parts of isophthalic acid, 27.7 parts of adipic acid, 7.10 parts of ethylene glycol, 15.8 parts of neopentyl glycol, and 17.9 parts of 1,6-hexanediol. While stirring, the mixture was gradually heated to 160 to 240 ° C. to carry out an esterification reaction. The reaction was carried out at 240 ° C. for 1 hour, and the acid value was measured. When the acid value became 15 or less, the reaction vessel was gradually depressurized to 1 to 2 Torr, and when the predetermined viscosity was reached, the reaction was stopped and taken out.
This polyester resin is a polyester polyol having a number average molecular weight of 10,000, a hydroxyl value of 11.2 and an acid value of 0.2 as measured by GPC, and a terminal primary hydroxyl group having an average bifunctionality.
<Polyol B>
(Terminal primary hydroxyl group is 2.5 functional, number average molecular weight 10,000 polyester polyol)
Reaction of 31.3 parts of isophthalic acid, 27.5 parts of adipic acid, 7.0 parts of ethylene glycol, 15.7 parts of neopentyl glycol, 17.8 parts of 1,6-hexanediol, and 0.54 parts of trimethylolpropane The can was charged and gradually heated to 160 to 240 ° C. with stirring under a nitrogen stream to carry out an esterification reaction. The reaction was carried out at 240 ° C. for 1 hour, and the acid value was measured. When the acid value became 15 or less, the reaction vessel was gradually depressurized to 1 to 2 Torr, and when the predetermined viscosity was reached, the reaction was stopped and taken out.
This polyester resin is a polyester polyol having a number average molecular weight of 10,000, a hydroxyl value of 14.1, an acid value of 0.3, and a terminal primary hydroxyl group having an average of 2.5 functionalities as measured by GPC.

<Polyol C>
(Terminal primary hydroxyl group is trifunctional, number average molecular weight 10,000 polyester polyol)
Reaction vessel containing 31.2 parts of isophthalic acid, 27.4 parts of adipic acid, 7.0 parts of ethylene glycol, 15.6 parts of neopentyl glycol, 17.7 parts of 1,6-hexanediol, and 1.14 parts of trimethylolpropane The mixture was gradually heated to 160 to 240 ° C. with stirring under a nitrogen stream to carry out an esterification reaction. The reaction was carried out at 240 ° C. for 1 hour, and the acid value was measured. When the acid value became 15 or less, the reaction vessel was gradually depressurized to 1 to 2 Torr, and when the predetermined viscosity was reached, the reaction was stopped and taken out.
This polyester resin is a polyester polyol having a number average molecular weight of 10,000, a hydroxyl value of 16.8, an acid value of 0.3, and a terminal primary hydroxyl group having an average trifunctionality as measured by GPC.
<Polyol D>
(Terminal primary hydroxyl group is tetrafunctional, number average molecular weight 10,000 000 polyester polyol)
A reactor can contain 30.8 parts of isophthalic acid, 27.1 parts of adipic acid, 6.9 parts of ethylene glycol, 15.4 parts of neopentyl glycol, 17.5 parts of 1,6-hexanediol, and 2.22 parts of trimethylolpropane. The mixture was gradually heated to 160 to 240 ° C. with stirring under a nitrogen stream to carry out an esterification reaction. It reacted at 240 degreeC for 1 hour, the acid value was measured, and when it became 15 or less, the reaction can was gradually pressure-reduced to 1-2 torr, and it gelatinized, if reaction was continued.

<Polyol E>
(Terminal primary hydroxyl group is bifunctional, number average molecular weight 4,000 polyester polyol)
31.5 parts of isophthalic acid, 27.7 parts of adipic acid, 7.1 parts of ethylene glycol, 15.8 parts of neopentyl glycol, and 17.9 parts of 1,6-hexanediol are charged into a reaction vessel and stirred under a nitrogen stream. The mixture was gradually heated to 160 to 240 ° C. to carry out the esterification reaction. The reaction was carried out at 240 ° C. for 1 hour, and the acid value was measured. When the acid value became 15 or less, the reaction vessel was gradually depressurized to 1 to 2 Torr, and when the predetermined viscosity was reached, the reaction was stopped and taken out.
This polyester resin was measured for molecular weight by GPC to obtain a number-average molecular weight of 4,000, a hydroxyl value of 28.1, an acid value of 0.1, and a terminal primary hydroxyl group having an average bifunctional polyester polyol.

<Polyol F>
(Terminal secondary hydroxyl group is 2.5 functional, number average molecular weight 10,000 polyester polyol)
Charge 32.7 parts of isophthalic acid, 28.8 parts of adipic acid, 7.33 parts of ethylene glycol, 16.4 parts of neopentyl glycol, 14.2 parts of 1,3-butanediol, and stir in a nitrogen stream. The mixture was gradually heated to 160 to 240 ° C. to carry out the esterification reaction. The reaction was carried out at 240 ° C. for 1 hour, and the acid value was measured. When the acid value became 15 or less, the reaction vessel was gradually depressurized to 1 to 2 Torr, and when the predetermined viscosity was reached, the reaction was stopped and taken out.
This polyester resin is a polyester polyol having a number average molecular weight of 10,000, a hydroxyl value of 11.2, an acid value of 0.5, and a terminal secondary hydroxyl group having an average of 2.5 functionalities.
<Polyol G>
(Terminal primary hydroxyl group is 1.3 functional, number average molecular weight 10,000 polyester polyol)
31.5 parts isophthalic acid, 27.7 parts adipic acid, 0.008 parts benzoic acid, 7.1 parts ethylene glycol, 15.8 parts neopentyl glycol, and 17.9 parts 1,6-hexanediol in a reaction can The esterification reaction was carried out by gradually heating to 160 to 240 ° C. while charging and stirring under a nitrogen stream. The reaction was carried out at 240 ° C. for 1 hour, and the acid value was measured. When the acid value became 15 or less, the reaction vessel was gradually depressurized to 1 to 2 Torr, and when the predetermined viscosity was reached, the reaction was stopped and taken out.
This polyester resin is a polyester polyol having a number average molecular weight of 10,000, a hydroxyl value of 7.3, an acid value of 0.2, and a terminal primary hydroxyl group having an average of 1.3 functional groups, as measured by GPC.
<Main agent 1>
A resin solution obtained by adding 1 part of a silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) to 100 parts of polyol A and 0.005 part of dioctyltin dilaurate as a catalyst is used as a main agent 1.
<Main agent 2>
A resin solution obtained by adding 100 parts of polyol B to 1 part of a silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.005 part of dioctyltin dilaurate as a catalyst is used as a main agent 2.
<Main agent 3>
Dioctyltin dilaurate using 100 parts of polyol B, 30 parts of bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., YD-012, hereinafter the same), 1 part of silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) and catalyst A resin solution having a solid content of 50% obtained by heating, dissolving and mixing the resin solution added at 0.005 part at 70 ° C. and diluting with ethyl acetate is used as the main agent 3.
<Main agent 4>
70 parts resin solution with 100 parts polyol B, 30 parts carbodiimide resin V-5 (Nisshinbo Co., Ltd.), 1 part silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.005 part dioctyltin dilaurate as a catalyst A resin solution having a solid content of 50% obtained by heating, dissolving and mixing at 0 ° C. and diluting with ethyl acetate is used as the main agent 4.
<Main agent 5>
100 parts of polyol C, 1 part of silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.005 part of dioctyltin dilaurate as a catalyst are heated, dissolved and mixed at 70 ° C. and diluted with ethyl acetate The resin solution having a solid content of 50% obtained as a main component 5 is used as the main agent 5.
<Main agent 6>
Tested due to polyol D gelation.
<Main agent 7>
Dioctyltin dilaurate using 100 parts of polyol E, 30 parts of bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., YD-012, hereinafter the same), 1 part of silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) and catalyst A resin solution having a solid content of 50% obtained by heating, dissolving, and mixing 0.005 parts of the resin solution at 70 ° C. and diluting with ethyl acetate is used as the main agent 7.
<Main agent 8>
Dioctyltin dilaurate using 100 parts of polyol F, 30 parts of bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., YD-012, hereinafter the same), 1 part of silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) and catalyst A resin solution having a solid content of 50% obtained by heating, dissolving, and mixing 0.005 parts of the resin solution at 70 ° C. and diluting with ethyl acetate is used as the main agent 8.
<Main agent 9>
Dioctyltin dilaurate using 100 parts of polyol G, 30 parts of bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., YD-012, hereinafter the same) and 1 part of silane coupling agent KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a catalyst A resin solution having a solid content of 50% obtained by heating, dissolving, and mixing 0.005 parts of the resin solution at 70 ° C. and diluting with ethyl acetate is used as the main agent 9.
<Curing agent 1>
Curing agent 1 is a hexafunctional isocyanate adduct (duranate MHG80 (Asahi Kasei Co., Ltd.) 30 parts, isophorone diisocyanate trimer 70 parts diluted with ethyl acetate to give a resin solution with a solid content of 50%. .
<Curing agent 2>
Curing agent 2 is a hexafunctional isocyanate adduct (30 parts of Duranate MHG80 (Asahi Kasei Co., Ltd.), 70 parts of trimethylolpropane adduct of isophorone diisocyanate diluted with ethyl acetate to give a resin solution with a solid content of 50%. And
<Curing agent 3>
5 functional isocyanate adduct (coronate 2875 (manufactured by Nippon Polyurethane Industry Co., Ltd.) 30 parts, isophorone diisocyanate trimer 70 parts diluted with ethyl acetate to give a resin solution with a solid content of 50% and curing agent 3 To do.
<Curing agent 4>
Curing agent 4 is a hexafunctional isocyanate adduct (60 parts of Duranate MHG80 (Asahi Kasei Co., Ltd.) and 40 parts of isophorone diisocyanate trimer diluted with ethyl acetate to give a resin solution with a solid content of 50%. .
<Hardening agent 5>
Hexafunctional isocyanate adduct (7 parts of Duranate MHG80 (Asahi Kasei Co., Ltd.), 93 parts of isophorone diisocyanate trimer diluted with ethyl acetate to give a resin solution with a solid content of 50% is used as curing agent 5. .
<Curing agent 6>
Curing agent 6 is a hexafunctional isocyanate adduct (80 parts of Duranate MHG80 (Asahi Kasei Co., Ltd.) and 20 parts of isophorone diisocyanate trimer diluted with ethyl acetate to give a resin solution with a solid content of 50%. .
<Curing agent 7>
Curing agent 7 is a trifunctional isocyanate adduct (duranate 24A (Asahi Kasei Co., Ltd.) 30 parts, isophorone diisocyanate trimer 70 parts diluted with ethyl acetate to give a resin solution with a solid content of 50%. .
<Hardening agent 8>
100 parts of trifunctional isocyanate adduct (100 parts of Duranate 24A (Asahi Kasei Co., Ltd., hexamethylene diisocyanate water adduct)) diluted with ethyl acetate to give a resin solution with a solid content of 50%, To do.
<Curing agent 9>
Curing agent 9 is obtained by diluting 100 parts of an isophorone diisocyanate trimer with ethyl acetate to give a resin solution having a solid content of 50%.
<Curing agent 10>
Curing agent 10 is a hexafunctional isocyanate adduct (45 parts of Duranate MHG80 (Asahi Kasei Co., Ltd.) and 55 parts of isophorone diisocyanate trimer diluted with ethyl acetate to give a resin solution with a solid content of 50%. .
<Adhesive composition>
Various adhesives and curing agents are blended at a ratio of 100: 14 (weight ratio), diluted with ethyl acetate, and adjusted to a solid content of 30% to obtain an adhesive solution.

  In Table 1, the combination of the main ingredient and hardening | curing agent in Examples 1-9 and Comparative Examples 1-8, and the polyisocyanate (B) mol with respect to 1 mol of all isocyanate groups are described.

<Performance test 1>
There are composite sheets using various substrates. Here, the adhesive solutions of Examples and Comparative Examples were used, and as a base material, an aluminum foil / fluorine film, PET / aluminum foil, metal-deposited PET / metal-deposited PET were laminated as shown below, and a laminated film (laminate) Material) was prepared and tested for foaming and moisture and heat resistance.

An adhesive is applied to a polyester film (Toray Co., Ltd., Lumirror X-10S, thickness 250 μm) with a dry laminator in an amount to be applied: 4 to 5 g / m ^2, and the solvent is stripped, and then an aluminum foil. (Thickness 50 μm) was laminated. Then, 40 degreeC and hardening (aging) for 3 days were performed, and the adhesive agent was hardened. The appearance of the laminate and the following tests were performed.

  The obtained multilayer film was put into a glass bottle, filled with distilled water, and the container was sealed. This was aged at 85 ° C. for 10 days, 20 days, and 30 days.

Each multi-layered film after aging was cut into a size of 200 mm × 15 mm, dried at room temperature for 6 hours, and then subjected to a T-type peel test at a load rate of 300 mm / min using a tensile tester according to the test method of ASTM D1876-61. I did it. The peel strength (N / 15 mm width) between the polyester film and the aluminum foil was shown as an average value of five test pieces.
<Performance test 2>

Each adhesive solution of Examples and Comparative Examples was applied to a fluorine film (DuPont Tedlar, thickness 38 μm) with an adhesive and a coating amount of 4 to 5 g / m ² by a dry laminator, and the solvent was volatilized. After that, an aluminum foil (thickness 50 μm) was laminated. Then, 40 degreeC and hardening (aging) for 3 days were performed, and the adhesive agent was hardened. The appearance of the laminate and the following tests were performed.

  The obtained multilayer film was put into a glass bottle, filled with distilled water, and the container was sealed. This was aged at 85 ° C. for 10 days, 20 days, and 30 days.

  Over time are each multilayer film was cut to a size of 200 mm × 15 mm, T-type peeling test at a loading rate 300 mm / min using room temperature after drying 6 hours, according to the test method of ASTM D1876-61, a tensile tester I did it. The peel strength (N / 15 mm width) between the polyester film and the aluminum foil was shown as an average value of five test pieces.

An adhesive is applied to a polyester film (Toray Co., Ltd., Lumirror X-10S, thickness 250 μm) with a dry laminator in an amount to be applied: 4 to 5 g / m ^2, and the solvent is stripped, and then an aluminum foil. (Thickness 50 μm) was laminated. Then, 40 degreeC and hardening (aging) for 3 days were performed, and the adhesive agent was hardened.

  The obtained multilayer film was put into a glass bottle, filled with distilled water, and the container was sealed. This was aged at 85 ° C. for 10 days, 20 days, and 30 days.

  Over time are each multilayer film was cut to a size of 200 mm × 15 mm, T-type peeling test at a loading rate 300 mm / min using room temperature after drying 6 hours, according to the test method of ASTM D1876-61, a tensile tester I did it. The peel strength (N / 15 mm width) between the polyester film and the aluminum foil was shown as an average value of five test pieces.

The evaluation is as follows.
Excellent in practical use: 5 N / 15 mm or more and laminate base material destruction practical range: 4 to 5 N / 15 mm and interfacial peeling between laminate base material and adhesive Practical lower limit: 2 to 4 N / 15 mm and interfacial peeling between laminate base material and adhesive Impossible: Less than 2N / 15mm and cohesive failure of adhesive

After the adhesive is applied to the metal vapor-deposited surface of a 12 μm metal vapor-deposited polyester film (Tech Barrier LX manufactured by Mitsubishi Resin Co., Ltd.) with a dry laminator in an amount of ⁴ to 5 g / m ^2, and the solvent is volatilized. And laminated on the metal deposition surface of the same film. Then, 40 degreeC and hardening (aging) for 3 days were performed, and the adhesive agent was hardened. The appearance of the laminate was observed.
The evaluation is as follows.
・: No foaming ・: Slight foaming is observed but practical range ・: Foam is seen and practical lower limit ×: Foam is severe and impractical

  As shown in Table 2, the adhesives of the examples had good foaming, excellent moisture and heat resistance, and were able to maintain the adhesive strength over a long period. In particular, good results were obtained in Examples 3 and 4. Since this test method promotes hydrolysis, it is considered to be a stricter test method with respect to heat and moisture resistance than an outdoor exposure test that is left outdoors. Therefore, it is considered that the adhesives of these examples are excellent in long-term wet heat resistance for outdoor use.

  For example, in JIS C 8917 (environmental test method and durability test method for crystalline solar cell module), a moisture resistance test B-2 is defined that it is durable for 1000 hours at 85 ° C. and 85% RH. It is known as a particularly severe test method. This time, the test was conducted in 85 ° C. warm water, but this test is severer than JIS C 8917, and the adhesives of these examples having long-term wet heat resistance are the solar cell back surface protection sheets having a multilayer structure. It means that the adhesive is suitable as an adhesive used between the sheet layers.

  In such a long-term moisture and heat resistance test, the solar cell back surface protection sheet retains sufficient interlayer adhesion strength (laminate strength) and does not cause delamination between the sheet layers, thereby protecting solar cell elements and maintaining power generation efficiency. Furthermore, it can contribute to the extension of the lifetime of the solar cell. Extending the lifetime of solar cells leads to the spread of solar cell systems and contributes to environmental conservation from the viewpoint of securing energy other than fossil fuels.

  The adhesive according to the present invention is used as an adhesive for multi-layer laminates (wall barriers, roofing materials, solar cell panel materials, window materials, outdoor flooring materials, certification protective materials, automobile members, etc.) for outdoor industrial applications such as buildings. It is possible to provide a laminated material that can provide strong adhesive strength, suppress a decrease in adhesive strength over time due to hydrolysis during outdoor exposure, and maintain strong adhesive strength over a long period of time.

The problem is that the polyester polyol (A) having an average of 1.5 to 3.5 primary hydroxyl groups in one molecule and having a number average molecular weight of 5,000 to 50,000 , and
Hexamethylene diisocyanate, or hexamethylene diisocyanate and allophanate of isophorone diisocyanate, isocyanurate or a complex thereof polyisocyanates with an average 4-7 isocyanate groups per molecule (B), and
A laminated sheet adhesive composition containing 0.1 to 5% by weight of a silane coupling agent (C) based on a polyester polyol (A) and dioctyltin dilaurate as a reaction accelerator. The laminated sheet characterized in that the isocyanate group of the polyisocyanate (B) having an average of 4 to 7 isocyanate groups is 0.1 to 0.7 mol with respect to 1 mol of all isocyanate groups in the composition. Solved by an adhesive composition.

The present invention also relates to the adhesive composition for laminated sheets, further comprising 0.1 to 5% by weight of the silane coupling agent (C) based on the polyester polyol (A).

The present invention further relates to the laminated sheet adhesive composition characterized in that it comprises a trimethylolpropane adduct and / or isocyanurate of isophorone diisocyanate isophorone diisocyanate.

The polyisocyanate (B) is a polyisocyanate having an average of 4 to 7 isocyanate groups in one molecule, and is an allophanate type or nurate type derivative of hexamethylene diisocyanate or hexamethylene diisocyanate and isophorone diisocyanate , , Its complex.

The problem is
In one molecule, it has 1.5 to 3.5 primary hydroxyl groups on average, and the number average molecular weight is
A polyester polyol (A) of 5,000 to 50,000 ,
Hexamethylene diisocyanate, or polyisocyanate (B) which is an allophanate, nurate or complex thereof of hexamethylene diisocyanate and isophorone diisocyanate and has an average of 4 to 7 isocyanate groups in one molecule ,
As polyisocyanate other than polyisocyanate (B)
Trimethylolpropane adduct of isophorone diisocyanate
And / or
Nuphorate of isophorone diisocyanate,
Silane coupling agent (C) based on polyester polyol (A)
0.1 to 5 % by weight ,
And an adhesive composition for laminated sheets containing dioctyltin dilaurate as a reaction accelerator,
The isocyanate group of the polyisocyanate (B) having an average of 4 to 7 isocyanate groups in one molecule is 0.1 to 0.7 mol with respect to 1 mol of all isocyanate groups in the composition. It is solved by the adhesive composition for laminated sheets.

The laminate according to claim 1 , further comprising a resin composition (D) comprising an epoxy resin and / or a carbodiimide resin based on the polyester polyol (A). The present invention relates to a sheet adhesive composition.

Claims (7)

Polyol (A) having 1.5 to 3.5 primary hydroxyl groups on average in one molecule and having a number average molecular weight of 5,000 to 50,000, and an average of 4 to 4 in one molecule An adhesive composition for laminated sheets containing a polyisocyanate (B) having 7 isocyanate groups,
The isocyanate group of the polyisocyanate (B) having an average of 4 to 7 isocyanate groups in one molecule is 0.1 to 0.7 mol with respect to 1 mol of all isocyanate groups in the composition. An adhesive composition for laminated sheets.   2. The adhesive composition for laminated sheets according to claim 1, comprising 0.1 to 5% by weight of the silane coupling agent (C) based on the polyol (A).   The adhesive composition for laminated sheets according to claim 1 or 2, comprising a resin composition (D) containing an epoxy resin and / or a carbodiimide resin based on the polyol (A).   4. The adhesive composition for laminated sheets according to claim 3, wherein the resin composition (D) is an epoxy resin having a number average molecular weight of 300 to 5,000. The polyisocyanate (B) is a polyisocyanate derived from hexamethylene diisocyanate or hexamethylene diisocyanate and isophorone diisocyanate, the adhesive composition for laminated sheets according to any one of claims 1 to 4. The polyisocyanate other than polyisocyanate (B) is a trimethylolpropane adduct of isophorone diisocyanate and / or a nurate of isophorone diisocyanate, and the adhesive composition for laminated sheets according to any one of claims 1 to 5 . The laminated body using the adhesive composition for laminated sheets in any one of Claims 1-6.