JP5962004B2 - Gas barrier cured resin composition and adhesive - Google Patents

Description

  The present invention relates to a resin composition for a subbarrier cured product having excellent gas barrier properties, and to a gas barrier adhesive using the same.

Packaging materials used for packaging food and beverages have functions such as strength, resistance to cracking, retort resistance, and heat resistance to protect the contents from various distribution, storage such as refrigeration and heat sterilization. In addition to this, a wide variety of functions are required such as excellent transparency so that the contents can be confirmed. On the other hand, when the bag is sealed by heat sealing, an unstretched polyolefin film having excellent heat processability is essential, but the unstretched polyolefin film has many functions that are insufficient as a packaging material.
For these reasons, a composite flexible film in which different polymer materials are combined is widely used as the packaging material. In general, it consists of a thermoplastic film layer as an outer layer having product protection and various functions, and a thermoplastic film layer as a sealant layer. For bonding, an adhesive is applied to the laminate film layer. A dry laminating method (see, for example, Patent Document 1) in which a multilayer film is manufactured by adhering a sealant layer is performed. However, the adhesive used in this application generally has only a function of adhering between different films.

  Further, in recent years, there has been a demand for further enhancement of functionality for multilayer films, and for the purpose of long-term preservation of food, oxygen barrier properties that prevent the entry of oxygen from the outside in order to suppress oxidation, carbon dioxide barrier properties, various aroma components, etc. A barrier function is also required. When imparting a barrier function to a multilayer film, unstretched polyolefin films used for the inner layer (sealant side) have poor gas barrier properties and are difficult to impart a barrier function by coating or vapor deposition. Therefore, a barrier function is often imparted to various films (polyester resins such as polyethylene terephthalate (hereinafter abbreviated as PET), polyamide resins, and stretched polyolefin resins) used on the outer layer side.

  In the case of providing a barrier function to these outer layer side films by coating, vinylidene chloride having a high retort resistance and oxygen barrier property has been frequently used as a barrier coating material. However, problems such as generation of dioxin during firing of waste There is. Further, when a polyvinyl alcohol resin or an ethylene-polyvinyl alcohol copolymer is used as a barrier coating material, the oxygen barrier property is high, but there are problems inferior to boil resistance and retort. On the other hand, a film in which a metal vapor deposition layer such as aluminum is provided as a gas barrier layer has a problem that it is opaque and the inside cannot be visually recognized, and the microwave oven cannot be used. In addition, a film provided with a vapor deposition layer of a metal oxide such as silica or alumina as a gas barrier layer is expensive and has a problem that the flexibility is poor and the barrier performance varies due to cracks and pinholes.

On the other hand, a method for imparting an oxygen barrier function to an adhesive used at the time of lamination is also known. This method has an advantage that a barrier film can be produced without using a film having a special gas barrier applied due to the steps and constitutions essential for producing a laminated film. On the other hand, the flexible molecular structure essential for adhesives generally has high gas permeability. For this reason, the adhesive ability and the barrier ability are often in a trade-off relationship, and this elimination increases the technical difficulty.
As a gas barrier material that can be used as an adhesive for such a laminated film, for example, in Patent Document 2, thermosetting includes a cured resin obtained by reacting an active hydrogen-containing compound (A) and an organic polyisocyanate compound (B). A gas-type gas barrier polyurethane resin, wherein the resin cured product contains a skeleton structure derived from metaxylene diisocyanate in an amount of 20% by weight or more, and among the compounds (A) and (B), a trifunctional or higher functional compound. A gas barrier composite film using a thermosetting gas barrier polyurethane resin, characterized in that the proportion is 7% by weight or more based on the total amount of (A) and (B) is described.
However, the solvent used for the adhesive is based on the premise that ethyl acetate, which is the mainstream as a diluting solvent for adhesives, can be used as a solvent from the viewpoint of recycling, whereas the resin must use acetone as the main solvent. As a result, there was a problem that workability was poor.
On the other hand, there are Non-Patent Documents 1 and 2 regarding the relationship between gas barrier properties and permacol values.

JP 2003-13032 A JP 2004-10656 A

New development of gas barrier fragrance packaging materials, Toray Research Center, pp. 10-13, published on March 25, 1997 M. Salame, Polymer Engineering and Science, December, 26, 22 (1986).

  The problem to be solved by the present invention is to provide an adhesive mainly composed of polyester polyol that can be used for food packaging and has excellent gas barrier properties, and provides a gas barrier resin composition that can be used for the adhesive. There is to do.

The present inventors are a resin composition for a gas barrier cured product containing a polyester polyol having two or more hydroxyl groups in one molecule as a functional group and an isocyanate compound, and a permacol of a residue excluding a terminal hydroxyl group of the polyester The value ranges from 44 to 60,
The gas barrier cured product obtained by curing the composition has a permacol value per mole of 50 or more, and the gas barrier cured product is dissolved in ethyl acetate which is a gas barrier property and a general-purpose solvent. It has been found that a multilayer film obtained by using the adhesive that can be used as an adhesive having excellent properties and excellent in gas barrier properties has solved the above problems.

That is, the present invention is a resin composition for gas barrier cured products containing a polyester polyol (A) having two or more hydroxyl groups in one molecule as a functional group and an isocyanate compound (B),
A resin composition for a gas barrier cured product having a permacol value in the range of 44 to 60 of the residue excluding the terminal hydroxyl group of the polyester polyol (A), and a gas barrier cured product obtained by curing the composition, A gas barrier cured product having a permacol value per mole of the cured product of 70 or more is provided.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a resin composition for a polyester polyurethane adhesive that is particularly excellent in solubility in ethyl acetate, which is a general-purpose solvent for a dry laminate adhesive, and has excellent gas barrier properties.

(Perma call value)
The permacol value per mole of the residue excluding the terminal hydroxyl group of the polyester polyol (A) used in the present invention is in the range of 44-60. Among these, the range of 44 to 55 is desirable. If the permacol value per mole of the residue excluding the terminal hydroxyl group of the polyester polyol is less than 44, the oxygen gas barrier property is difficult to develop, and if it exceeds 60, it tends to be difficult to dissolve in the general-purpose solvent ethyl acetate. Therefore, it is not preferable.
According to Non-Patent Documents 1 and 2, the permacol value per 1 mol of the terminal hydroxyl group residue of the polyester polyol compound having two or more hydroxyl groups can be calculated from the permacol values corresponding to the polymer segments shown in Table 1. .

  For example, the permacol value per mole of the residue excluding the terminal hydroxyl group of ethylene glycol phthalate (chemical formula 1, molecular weight 600) is calculated as follows.

P is

Therefore, the average number of repetitions n is P = 53.3 from n = 2.76.

  Here, in the permacol value P, the relationship of the following formula (a) is established between the cohesive energy density δ and the free volume fV.

Since the gas barrier property is easily developed when the numerical value of the permacol value P is increased, it is necessary to increase the cohesive energy density δ or reduce the free volume fraction fV of the material that exhibits the gas barrier property. However, since a material having a high cohesive energy density has high polarity, the solubility in a solvent is impaired.
The inventors of the present invention have found that a polyester polyol having a permacol value in the range of 44 to 60 is advantageous in developing a barrier property without impairing the solubility in ethyl acetate by conducting detailed studies. .

On the other hand, for the cured product obtained by the reaction, the larger the permacol P, the more advantageous. However, as shown in Table 1, the permacol value for the functional group formed by the isocyanate group such as urethane group and urea group upon curing is as shown in Table 1. So far, the relationship between the permacol value and the oxygen transmission rate has not been studied. As a result of intensive studies, the present inventors have calculated the permacol value of the urethane group as 260 per cc, which is the permacol value of the amide group at the time of wet, and the permacol value of the urea group as 520 cal / cc, as calculated by the calculation method described later. Then, it discovered that a favorable correlation was obtained between permacol and oxygen permeability in a polyester polyurethane system, and the present invention was achieved.

(Polyester polyol with permacol in the range of 44-60)
The polyester polyol used in the present invention is obtained by a condensation reaction of a bifunctional or higher polyhydric alcohol and a bifunctional or higher polybasic acid, and the permacol value per mole of the residue excluding the terminal hydroxyl group is It may be in the range of 44-60.
Examples of the bifunctional or higher polyhydric alcohol include ethylene glycol, propanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, diethylene glycol, glycerin and the above-mentioned polyhydric alcohols. Alkylene oxide adducts of polyhydric alcohols such as catechol, resorcinol, hydroquinone, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,2-biphenol and the like. Can be mentioned.
Of these, ethylene glycol, 1,2-propanediol, 1,3-bishydroxyethylbenzene, 1,6-dihydroxynaphthalene ethylene oxide adduct and the like are preferable.

Bifunctional or higher polybasic acids include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, diphenic acid, biphenylenedicarboxylic acid, diphenic acid trimellitic acid, pyromellitic acid, and acid anhydrides of the above aromatic polybasic acids And aliphatic polybasic acids such as fumaric acid, maleic acid and succinic acid.
Of these, phthalic acid, 1,2-naphthalenedicarboxylic acid, and diphenic acid are preferable.

  The aromatic polyvalent carboxylic acid in which the acyl group, which is a raw material of the polyester component, is substituted in the ortho position, or its anhydride has an asymmetric structure. Therefore, it is presumed that the rotation of the molecular chain of the resulting polyester is suppressed, and it is presumed that this provides excellent oxygen barrier properties. Moreover, since the crystallinity which inhibits base-material adhesiveness due to this asymmetric structure is low, sufficient base-material adhesiveness is provided and it is estimated that it is excellent in adhesive force and oxygen barrier property. Furthermore, when used as a dry laminate adhesive, the solvent solubility, which is essential, is also high, so that it has excellent handling characteristics.

Among them, polyester polyols using ethylene glycol as the polyhydric alcohol, phthalic acid as the polybasic acid, 1,3-bishydroxyethylbenzene as the polyhydric alcohol, polyester polyol using phthalic acid as the polybasic acid, Polyester polyol using ethylene glycol as polyhydric alcohol, 1,2-naphthalenedicarboxylic acid as polybasic acid, polyester polyol using ethylene glycol as polyhydric alcohol and diphenic acid as polybasic acid is adhesive, acetic acid Excellent balance between solubility in ethyl and barrier properties

(Amorphous polyester)
The polyester used in the present invention is desirably amorphous. Being amorphous, it is advantageous for maintaining the flexibility as a curable resin composition and developing the adhesiveness required as an adhesive resin.
In order to obtain such an amorphous polyester, there is a method of introducing a structure that tends to have an asymmetric structure around the polymer main chain or using a mixture of crystalline polyesters at a high temperature. As an example of the former, when benzenedicarboxylic acid is used as the polybasic acid of the polyester raw material, there is a method of using phthalic acid instead of terephthalic acid. Examples thereof include a raw material having a branch in a polyhydric alcohol, such as using 1,2-propanediol in place of ethylene glycol. Examples of the latter include a method of using terephthalic acid and isophthalic acid in combination.

(Hydroxyl value of polyester polyol)
The polyester polyol used in the present invention becomes a resin cured product by a reaction between a terminal hydroxyl group and an isocyanate. The amount of this reactive group is represented by the hydroxyl value. The hydroxyl value is calculated by the following formula (b) as the hydroxyl value ZmgKOH / g obtained by the hydroxyl value measuring method described in JIS-K0070.

  The polyester polyol used in the present invention preferably has a hydroxyl value of 80 or more, more preferably 100 or more. If the hydroxyl value is less than 80, the concentration of urethane and urea bonding groups formed from the curable resin composition may be lowered, and the oxygen barrier property may be lowered.

The reason why the gas barrier polyester urethane adhesive obtained by reacting a polyester polyol having a permacol value in the range of 44 to 60 with an isocyanate compound can ensure oxygen barrier properties and dry laminate adhesiveness is estimated as follows. doing.

As described above, in order to increase the numerical value of the permacol value and develop gas barrier properties, it is necessary to introduce a highly polar group that increases the cohesive energy density. When isocyanate reacts with a hydroxyl group, a carbamate group reacts with 2 moles of isocyanate and 1 mole of water to form a urea bond, so that the urethane bond and urea bond formed by the curing reaction make the cured resin composition highly polar. I can do it. Its cohesive energy is comparable to an amide bond. Since the ratio of the curing agent in the composition is proportional to the hydroxyl value to be reacted, the polyester polyol having a permacol value in the range of 44 to 60 has a hydroxyl value of 80 or more, and this effect is exhibited to the maximum.

  On the other hand, high crosslink density and flexibility are required for adhesiveness, but since polyester polyol is an amorphous polyester with flexibility, it is assumed that it is made by imparting adhesiveness while leaving moderate flexibility. ing. Thus, the oxygen barrier as a cured resin can be obtained by curing the amorphous polyester polyol having a permacol value in the range of 44 to 60 with an hydroxyl value of 80 or more and an isocyanate with high polarity and appropriate flexibility. It is presumed that the property and adhesion to dry laminate can be secured.

The polyester polyol of the present invention can be obtained by a known polyester production method. Specifically, it can be synthesized by a production method in which the reaction is carried out while removing generated water from the system at a reaction temperature of 200 to 220 ° C. in the presence of a catalyst.
As a specific example, after the triol having an isocyanuric ring used as a raw material, an aromatic polycarboxylic acid in which the carboxylic acid is substituted in the ortho position, or an anhydride thereof, and a polyhydric alcohol component are collectively charged Then, the temperature is increased while stirring and mixing to cause a dehydration condensation reaction. 1 mgKOH / g or less by the acid value measurement method described in JIS-K0070, and the hydroxyl value ZmgKOH / g obtained by the hydroxyl value measurement method described in JIS-K0070 is the value on the right side of the following formula (b) (mgKOH / The target polyester polyol can be obtained by continuing the reaction until it falls within ± 5% of g).

  Alternatively, each raw material may be reacted in multiple stages. Moreover, you may prepare so that a hydroxyl value may enter into less than +/- 5%, adding the diol component which volatilized at reaction temperature.

  Examples of the catalyst used in the reaction include acids such as tin-based catalysts such as monobutyltin oxide and dibutyltin oxide, titanium-based catalysts such as tetra-isopropyl-titanate and tetra-butyl-titanate, and zirconia-based catalysts such as tetra-butyl-zirconate. A catalyst is mentioned. It is preferable to use a combination of the titanium-based catalyst such as tetra-isopropyl-titanate and tetra-butyl-titanate, which has high activity for ester reaction, and the zirconia catalyst. The catalyst amount is used in an amount of 1 to 1000 ppm, more preferably 10 to 100 ppm, based on the total weight of the reaction raw material used. If it is less than 1 ppm, it is difficult to obtain an effect as a catalyst, and if it exceeds 1000 ppm, the subsequent urethanization reaction tends to be inhibited.

(Adhesive hardener)
The curing agent used in the present invention is not particularly limited as long as it is a curing agent capable of reacting with the hydroxyl group of the polyester polyol, and known curing agents such as polyisocyanates and epoxy compounds can be used. Among these, it is preferable to use polyisocyanate from the viewpoints of adhesiveness and retort resistance.

  Polyisocyanate compounds include aromatic and aliphatic diisocyanates and trivalent or higher polyisocyanates, which may be either low molecular compounds or high molecular compounds. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimers of these isocyanate compounds, and excess of these isocyanate compounds Amount, for example, ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerin, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, Diethanolamine, triethanolamine Low-molecular weight active hydrogen compound and alkylene oxide adducts thereof, such as m-xylylenediamine, various polyester polyols, polyether polyols, polymeric active hydrogen compound such as an adduct obtained by reacting the polyamides and the like.

  The isocyanate compound may be a blocked isocyanate. As the isocyanate blocking agent, for example, phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol, acetoxime, methyl ethyl ketoxime, cyclohexanone oxime oximes, methanol, Alcohols such as ethanol, propanol and butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; tertiary alcohols such as t-butanol and t-pentanol; Examples include lactams such as caprolactam, δ-valerolactam, γ-butyrolactam, β-propylolactam, and other aromatic amines, imides, acetylacetate. , Acetoacetic ester, active methylene compounds such as malonic acid ethyl ester, mercaptans, imines, ureas, and also such as diaryl compounds sodium bisulfite. The blocked isocyanate can be obtained by subjecting the above isocyanate compound and an isocyanate blocking agent to an addition reaction by a conventionally known appropriate method.

Among them, it is preferable that the curing agent is the polyisocyanate, and when the polyisocyanate includes the metaxylene skeleton, oxygen barrier properties are improved by π-π stacking of aromatic rings as well as hydrogen bonds of the urethane group. It is preferable because it can be.
Examples of the polyisocyanate containing a metaxylene skeleton include xylene diisocyanate trimer, burette synthesized by reaction with amine, and adduct formed by reaction with alcohol. The adduct body is more preferable because the solubility of the polyisocyanate in the organic solvent used for the dry laminate adhesive is easily obtained.
As the adduct, an adduct obtained by reacting with an alcohol appropriately selected from the above low molecular active hydrogen compounds can be used. Among them, addition of trimethylolpropane, glycerin, triethanolamine, metaxylenediamine to ethylene oxide Adduct bodies with objects are particularly preferred.

  In the polyester polyol compound and the curing agent, the ratio of the polyester polyol compound having an isocyanuric ring and the curing agent is such that the hydroxyl group of the polyester polyol compound having an isocyanuric ring and the reaction component of the curing agent are 1/1 to 1/5 ( (Equivalent ratio) is preferably blended, more preferably 1/1 to 1/3. If the curing agent component is excessive beyond this range, the surplus curing agent component may remain and bleed out from the adhesive layer after bonding. On the other hand, if the curing agent component is insufficient, the adhesive strength is insufficient. There is a fear.

  The said hardening | curing agent can also use together the well-known hardening | curing agent or accelerator selected according to the kind. Examples of the adhesion promoter include silane coupling agents such as hydrolyzable alkoxysilane compounds, titanate coupling agents, aluminum coupling agents, and epoxy resins. Silane coupling agents and titanate coupling agents are also preferred in terms of improving the adhesive to various film materials.

(Permacol value of isocyanate and polyisocyanate)
In the present application, the permacol value as a cured resin constituent of a curing agent that reacts with a polyester polyol is calculated by converting an isocyanate group into a carbamate group.
For example, in the case of polyisocyanate (compound 2) consisting of meta-xylylene diisocyanate and trimethylolpropane,

  By reacting with the polyester polyol, the structure changes to the following (Chemical Formula 3) to form a cured film.

  The permacol value of the chemical moiety having the above chemical structure (molecular weight 749.74) corresponding to 1 mol of polyisocyanate composed of meta-xylylene diisocyanate and trimethylolpropane is calculated based on the values in Table 3.

The calculation is performed in the same manner as above, and P = 88.3 is calculated.

  Similarly, in the case of meta-xylylene diisocyanate, by reacting with the polyester polyol, it changes to the following structure (Chemical Formula 4) and forms a cured film.

  The permacol value of the chemical moiety having the above chemical structure (molecular weight 222.20) corresponding to 1 mol of meta-xylylene diisocyanate is calculated based on the values in Table 4 and calculated as P = 122.

In the present application, the permacol value as the cured resin component of the curing agent added in excess of the equivalent amount of the hydroxyl group of the polyester polyol is calculated on the assumption that the isocyanate group has been converted to a urea group.
The urea group reacts with 2 moles of isocyanate and 1 mole of water present in the atmosphere to form 1 mole of urea, so 1 mole of polyisocyanate is 0.5 mole of polyisocyanate and 0.5 mole of polyisocyanate. To a residue other than the terminal NCO of the polyisocyanate.

  For example, 1 mol of polyisocyanate composed of meta-xylylene diisocyanate and trimethylolpropane corresponds to 1 mol of polyisocyanate composed of meta-xylylene diisocyanate and trimethylolpropane in which the terminal isocyanate group is changed to a urea group. Chemical structure (Chemical Formula 5) (molecular weight 746.79) 0.5 mol,

  Changed to 0.5 mol of the above chemical structure (Chemical Formula 6) (molecular weight 572.67) corresponding to 1 mol of polyisocyanate consisting of meta-xylylene diisocyanate and trimethylolpropane, excluding the terminal isocyanate group. Think to form.

  The permacol value corresponding to 1 mol of polyisocyanate composed of meta-xylylene diisocyanate and trimethylolpropane added in excess was calculated based on the values in Table 5 for the site changed to a urea group. = 125.5.

  On the other hand, for the part corresponding to 1 mol of polyisocyanate composed of meta-xylylene diisocyanate and trimethylolpropane, excluding the terminal isocyanate group, P = 59.7 is calculated based on the values in Table 6. .

Therefore, permacol value P as a cured resin constituent of 1 mole of polyisocyanate composed of meta-xylylene diisocyanate and trimethylolpropane added in excess of the equivalent amount of hydroxyl group of polyester polyol is:
P = 0.5 × 125, 5 + 0.5 × 59.7 = 92.6
It becomes.

  Similarly, 1 mole of metaxylylene diisocyanate was considered to have changed to 1 mole of the above structure (Chemical Formula 7) excluding one terminal isocyanate group to a urea group and the other terminal isocyanate group. Based on the value, P = 152.5 is calculated.

  In the present application, the permacol value per mole of the curable resin composition is considered to be the number of moles of the residue excluding the terminal hydroxyl group from the polyester polyol which is the main component constituting the adhesive resin of the present application, and the curing agent is changed by the curing reaction. It is calculated from the number of moles of the compound having the chemical structure.

ここで、Ｎｉは残気、硬化剤のモル数
Ｐｉは残基、硬化剤夫々に与えられたパーマコール値
である。

Here, Ni is residual air, and the number of moles of the curing agent Pi is a permacol value given to each of the residue and the curing agent.

For example, the permacol value per mole of a cured product obtained by reacting a polyester having a molecular weight of 600 having a permacol value of 53.3 with an equivalent amount of a trifunctional polyisocyanate composed of meta-xylylene diisocyanate and trimethylolpropane is ,
It is calculated as (1 × 53.3 + 2/3 × 88.3) / (1 + 2/3) = 68.6.

  The permacol value per mole of the curable resin composition is 70 or more, desirably 80 or more. When the permacol value per mole of the curable resin composition is less than 70, it is not preferable because the barrier property of the resin cured product is hardly exhibited.

(Adhesive and other ingredients)
The adhesive of this invention may mix | blend various additives in the range which does not impair gas barrier property. Examples of additives include inorganic fillers such as silica, alumina, mica, talc, aluminum flakes, and glass flakes, layered inorganic compounds, stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, etc.), plasticizers, Examples thereof include an antistatic agent, a lubricant, an antiblocking agent, a colorant, a filler, and a crystal nucleating agent. Examples of the swellable inorganic layered compound include hydrous silicates (phyllosilicate minerals, etc.), kaolinite group clay minerals (halloysite, kaolinite, enderite, dickite, nacrite, etc.), antigolite group clay minerals (anti Golite, chrysotile, etc.), smectite clay mineral (montmorillonite, beidellite, nontronite, saponite, hectorite, soconite, stevensite, etc.), vermiculite clay mineral (vermiculite, etc.), mica or mica clay mineral (white mica, Mica such as phlogopite, margarite, tetrasilic mica, teniolite, etc.). These minerals may be natural clay minerals or synthetic clay minerals. The swellable inorganic layered compounds are used alone or in combination of two or more.

  Moreover, a well-known acid anhydride can also be used together as a method of improving the acid resistance of an adhesive bond layer. Examples of the acid anhydride include phthalic acid anhydride, succinic acid anhydride, het acid anhydride, hymic acid anhydride, maleic acid anhydride, tetrahydrophthalic acid anhydride, hexahydraphthalic acid anhydride, tetraprom phthalic acid Anhydride, tetrachlorophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenotetracarboxylic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 5- (2 , 5-oxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, styrene maleic anhydride copolymer and the like.

  Moreover, you may add the compound etc. which have an oxygen trap function further as needed. Examples of the compound having an oxygen scavenging function include low molecular organic compounds that react with oxygen such as hindered phenols, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, pyrogallol, cobalt, manganese, nickel, iron, Examples include transition metal compounds such as copper.

  Moreover, in order to improve the adhesiveness with respect to various film materials immediately after application | coating, you may add tackifiers, such as a xylene resin, a terpene resin, a phenol resin, and a rosin resin, as needed. When adding these, the range of 0.01-5 weight part is preferable with respect to 100 weight part of total amounts of an epoxy resin and an epoxy resin hardening | curing agent.

(Adhesive form)
The adhesive of the present invention may be either a solvent type or a solventless type. In the case of the solvent type, the solvent is used as a reaction medium during the production of the polyester polyol and the curing agent, and further as a diluent during coating. Examples of solvents that can be used include esters such as ethyl acetate, butyl acetate and cellosolve acetate, ketones such as acetone, methyl ethyl ketone, isobutyl ketone and cyclohexanone, ethers such as tetrahydrofuran and dioxane, and aromatic hydrocarbons such as toluene and xylene. , Halogenated hydrocarbons such as methylene chloride and ethylene chloride, dimethyl sulfoxide, dimethyl sulfoamide and the like. Of these, it is usually preferable to use ethyl acetate or methyl ethyl ketone.

  The adhesive of the present invention can be used by being applied to a substrate film or the like. The coating method is not particularly limited and may be performed by a known method. For example, in the case of a solvent type whose viscosity can be adjusted, it is often applied by a gravure roll coating method or the like. Moreover, when it is a solventless type and has a high viscosity at room temperature and is not suitable for gravure roll coating, it can be coated with a roll coater while heating. When using a roll coater, it is preferable to apply in a state of heating from room temperature to about 120 ° C. so that the viscosity of the adhesive of the present invention is about 500 to 2500 mPa · s.

  The adhesive of the present invention can be used as an oxygen barrier adhesive for various applications that require oxygen barrier properties against polymers, paper, metals, and the like. Hereinafter, an adhesive for film lamination will be described as one of specific applications.

The adhesive of the present invention can be used as an adhesive for film lamination. Since the laminated film is excellent in oxygen barrier properties, it can be used as an oxygen barrier film.
The film for lamination used in the present invention is not particularly limited, and a thermoplastic resin film can be appropriately selected according to a desired application. For example, for food packaging, PET film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low density polyethylene film, HDPE: high density polyethylene film) and polypropylene film (CPP: unstretched polypropylene film, OPP: Polyolefin film such as biaxially stretched polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, and the like. These may be subjected to stretching treatment. As the stretching treatment method, it is common to perform simultaneous biaxial stretching or sequential biaxial stretching after the resin is melt-extruded by extrusion film forming method or the like to form a sheet. Further, in the case of sequential biaxial stretching, it is common to first perform longitudinal stretching and then perform lateral stretching. Specifically, a method of combining longitudinal stretching using a speed difference between rolls and transverse stretching using a tenter is often used.
Moreover, you may perform various surface treatments, such as a flame treatment and a corona discharge treatment, as needed so that the adhesive layer without defects, such as a film | membrane piece and a repellency, may be formed in the film surface.

After the adhesive of the present invention is applied to one of the thermoplastic resin films, the other thermoplastic resin film is laminated and bonded together by lamination, whereby the oxygen barrier film of the present invention is obtained. As the lamination method, known lamination such as dry lamination, non-solvent lamination, extrusion lamination, etc. can be used.
Specifically, in the dry lamination method, the adhesive of the present invention is applied to one of the base films by the gravure roll method, and the other base film is stacked and bonded by dry lamination (dry lamination method). The temperature of the laminate roll is preferably about room temperature to 60 ° C.
In addition, non-solvent lamination is performed on the surface immediately after applying the adhesive of the present invention, which has been heated to room temperature to about 120 ° C., with a roll such as a roll coater heated to about room temperature to about 120 ° C. A laminate film can be obtained by laminating film materials. The laminating pressure is preferably about 10 to 300 kg / cm ² .
In the case of the extrusion laminating method, the organic solvent solution of the adhesive of the present invention is applied to the base film as an adhesion aid (anchor coating agent) with a roll such as a gravure roll, and the solvent is dried and cured at room temperature to 140 ° C. After the reaction, a laminate film can be obtained by laminating the polymer material melted by the extruder. The polymer material to be melted is preferably a polyolefin resin such as a low density polyethylene resin, a linear low density polyethylene resin, or an ethylene-vinyl acetate copolymer resin.

  The oxygen barrier film of the present invention is preferably subjected to aging after production. If polyisocyanate is used as a curing agent, the aging condition is from room temperature to 80 ° C. and for 12 to 240 hours. During this period, the polyester polyol and the curing agent react to produce adhesive strength.

  In the present invention, in order to provide a higher barrier function, a film in which a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina may be used as needed.

  The adhesive of the present invention can be preferably used as an adhesive for laminated films formed by bonding a plurality of the same or different resin films. The resin film may be appropriately selected depending on the purpose. For example, when used as a packaging material, the outermost layer is a thermoplastic resin film selected from PET, OPP, and polyamide, and the innermost layer is unstretched polypropylene. (Hereinafter abbreviated as CPP), a composite film consisting of two layers using a thermoplastic resin film selected from a low density polyethylene film (hereinafter abbreviated as LLDPE), or an outermost layer selected from, for example, PET, polyamide and OPP A three-layer composite using a thermoplastic resin film, a thermoplastic resin film that forms an intermediate layer selected from OPP, PET, and polyamide, and a thermoplastic resin film that forms an innermost layer selected from CPP and LLDPE A heatable film that forms an outermost layer selected from, for example, OPP, PET, and polyamide. Selected from a thermoplastic resin film, a thermoplastic film forming a first intermediate layer selected from PET and nylon, and a thermoplastic film forming a second intermediate layer selected from PET and polyamide, LLDPE, and CPP A composite film composed of four layers using a thermoplastic resin film forming the innermost layer can be preferably used as a food packaging material as an oxygen and water vapor barrier film. Thus, the use of the adhesive of the present invention is not limited to PET / CPP films and can be widely used.

  Since the adhesive of the present invention is characterized by having a high oxygen barrier property, the laminate film formed by the adhesive is composed of a PVDC coat layer, a polyvinyl alcohol (PVA) coat layer, an ethylene-vinyl alcohol copolymer. (EVOH) Film layer, metaxylylene adipamide film layer, inorganic vapor deposited film layer deposited with alumina, silica, etc. To do. Moreover, the gas barrier property of the obtained film can also be remarkably improved by using together as an adhesive agent which bonds these conventional gas barrier material and sealant material together.

  Next, the present invention will be specifically described with reference to examples and comparative examples. Unless otherwise indicated, “parts” and “%” are based on weight.

(Production Example 1) Polyester polyol composed of ethylene glycol and orthophthalic acid having a number average molecular weight of 600 “EGoPA Mn600” Production method 747.31 parts of ethylene glycol in a polyester reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, a snider tube, and a condenser Then, 1252.70 parts of phthalic anhydride and 0.02 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “EGoPA Mn600” having a number average molecular weight of 600. This polyester polyol has a repetitive number n = 2.80. The permacol value of the residue excluding the terminal hydroxyl group is 53.3. The hydroxyl value was 187.0.

(Production Example 2) Polyester polyol composed of ethylene glycol and 1,2-naphthalenedicarboxylic acid anhydride “EGoNA Mn 600” production method 148.1 parts of phthalic anhydride in Production Example 1 were changed to 198.17 parts, ethylene glycol 747.31 A polyester polyol “EGoNA Mn 600” having a number average molecular weight of 600 was obtained in the same manner as in Production Example 1 except that the amount was changed to 94.52 parts. The polyester polyol has a repeating number n = 2.22 and the permacol value of the residue excluding the terminal hydroxyl group is 53.3.
The hydroxyl value was 187.0.

(Production Example 3) Polyester polyol composed of ethylene glycol and diphenic acid “EGDPA Mn 600” production method In Production Example 1, 148.1 parts of phthalic anhydride is 242.23 parts of diphenic acid, and 747.31 parts of ethylene glycol is 97. A polyester polyol “EGDPA Mn 600” having a number average molecular weight of 600 was obtained in the same manner as in Production Example 1 except that the amount was changed to 67 parts. The polyester polyol has a repeating number n = 2.00, and the permacol value of the residue excluding the terminal hydroxyl group is 54.4. The hydroxyl value was 187.0.

(Production Example 4) Polyester polyol of 1,3-bishydroxyethylbenzene and orthophthalic acid having a number average molecular weight of 600 “1,3-BHEBoPA Mn600” Production method Polyester reaction equipped with a stirrer, nitrogen gas introduction tube, snider tube, and condenser A container is charged with 37.22 parts of 1,3-bishydroxyethylbenzene, 148.12 parts of phthalic anhydride, and 0.02 part of titanium tetraisopropoxide, and gradually the upper temperature of the rectifying tube does not exceed 100 ° C. The internal temperature was kept at 220 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “1,3-BHEBoPA Mn600” having a number average molecular weight of 600. The number of repetitions of this polyester polyol n = 1.22 The permacol value of the residue excluding the terminal hydroxyl group is 46.4. The hydroxyl value was 187.0.

(Production Example 5) Polyester polyol having a number average molecular weight of 600 consisting of diethylene glycol and orthophthalic acid “DEGoPA Mn600” production method In a polyester reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, a snider tube, and a condenser, 164.73 parts of diethylene glycol, anhydrous 148.12 parts of phthalic acid and 0.02 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “DEGoPA Mn600” having a number average molecular weight of 600. The permacol value of the residue excluding the repeating number n = 2.09 terminal hydroxyl group of this polyester polyol is 44.4. The hydroxyl value was 187.0.

(Production Example 6) Polyester polyol consisting of ethylene glycol and orthophthalic acid having a number average molecular weight of 900 “EGoPA Mn900” Production method 80.12 parts of ethylene glycol in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, snider tube, condenser 148.12 parts of phthalic acid and 0.02 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “EGoPA Mn900” having a number average molecular weight of 900. The permacol value of the residue excluding the repeating number n = 4.36 terminal hydroxyl group of this polyester polyol is 54.4. The hydroxyl value was 124.7.

Production Example 7 Polyester polyol composed of ethylene glycol and orthophthalic acid having a number average molecular weight of 1100 “EGoPA Mn1100” Production method 77.24 parts of ethylene glycol in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction pipe, snider pipe and condenser Then, 148.12 parts of phthalic anhydride and 0.02 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “EGoPA Mn1100” having a number average molecular weight of 1100. The permacol value of the residue excluding the repeating number n = 5.40 terminal hydroxyl group of this polyester polyol is 55.2. The hydroxyl value was 102.0.

(Production Example 8) Polyester polyol having a number average molecular weight of 900 consisting of 1,3-bishydroxyethylbenzene and orthophthalic acid “1,3-BHEBoPA Mn900” Production method Polyester reaction equipped with a stirrer, nitrogen gas introduction tube, snider tube, and condenser A container is charged with 30.51 parts of 1,3-bishydroxyethylbenzene, 148.12 parts of phthalic anhydride, and 0.02 part of titanium tetraisopropoxide, and is gradually added so that the upper temperature of the rectification tube does not exceed 100 ° C. The internal temperature was kept at 220 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “1,3-BHEBoPA Mn900” having a number average molecular weight of 900. The permacol value of the residue excluding the repeating number n = 1.47 terminal hydroxyl group of this polyester polyol is 48.3. The hydroxyl value was 124.7.

(Production Example 9) Polyester polyol having a number average molecular weight of 2000 consisting of 1,6-hexanediol and adipic acid “HGAA Mn2000” Production method In a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, snider tube, condenser, Charge 137.77 parts of 6-hexanediol, 146.14 parts of adipic acid, and 0.02 part of titanium tetraisopropoxide, and gradually heat the internal temperature by gradually heating so that the upper temperature of the rectification tube does not exceed 100 ° C. Maintained at 220 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated, and a polyester polyol “HGAA Mn2000” having a number average molecular weight of 2000 was obtained. The permacol value of the residue excluding the repeating number n = 8.24 terminal hydroxyl group of this polyester polyol is 31.2. The hydroxyl value was 56.1.

(Production Example 10) Production of Adduct Body of Ethylene Glycol and Metaxylene Diisocyanate 124.14 parts of ethylene glycol was added to a reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, a cooling condenser, and a dropping funnel and heated to 70 ° C. Stir. There, 188 parts of xylylene diisocyanate was slowly added dropwise over 1 hour. Stirring was continued at 70 ° C. for 3 hours after the dropwise addition to obtain an XDI adduct having a molecular weight of 312 to which 2 moles of ethylene oxide had been added. The permacol value excluding the terminal hydroxyl group of this adduct is 74.4.
The hydroxyl value was 112.2.

(Production Example 11) Polyester polyol having a number average molecular weight of 2000 consisting of diethylene glycol and phthalic acid “DEGoPA Mn2000” Production method 125.33 parts of diethylene glycol, anhydrous, in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction pipe, snider pipe, condenser 148.12 parts of phthalic acid and 0.02 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “EGAA Mn1000” having a number average molecular weight of 1000. The number of repetitions of this polyester polyol n = 8.02 The permacol value of the residue excluding the terminal hydroxyl group is 47.8. The hydroxyl value was 56.1.

(Production Example 12) Polyester polyol “DEGoPA Mn2000” made of diethylene glycol and phthalic acid having a number average molecular weight of 2000 “DEGoPA Mn2000” production method In a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction pipe, snider pipe, condenser, 125.33 parts of diethylene glycol 148.12 parts of phthalic acid and 0.02 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “DEGoPA Mn2000” having a number average molecular weight of 1000. The number of repetitions of this polyester polyol n = 8.02 The permacol value of the residue excluding the terminal hydroxyl group is 47.8. The hydroxyl value was 56.1.

(Production Example 13) Polyester polyol having a number average molecular weight of 2000 consisting of nonanediol and phthalic acid "NDoPA Mn2000" Production method 190.2 parts of nonanediol in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, snider tube, condenser, 148.12 parts of phthalic anhydride and 0.02 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol “EGAA Mn1000” having a number average molecular weight of 2000. The polyester polyol repeat number n = 6.33 The permacol value of the residue excluding the terminal hydroxyl group is 31.3. The hydroxyl value was 56.1.

(Production Example 14) Polyester polyol having a number average molecular weight of 2000 consisting of hexdiol and phthalic acid “HGPA Mn2000” Production method 137.77 parts of hexanediol in a polyester reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, a Snyder tube, and a condenser, anhydrous 148.12 parts of phthalic acid and 0.02 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated, and a polyester polyol “HGoPA Mn2000” having a number average molecular weight of 2000 was obtained. The number of repetitions of this polyester polyol n = 6.33 The permacol value of the residue excluding the terminal hydroxyl group is 37.4. The hydroxyl value was 56.1.

(Production Example 15) Adduct body production method comprising trimethylolpropane and metaxylene diisocyanate 134.17 parts of trimethylolpropane at 110 ° C. in a reaction vessel equipped with a stirrer, nitrogen gas inlet tube, vacuum pump, cooling condenser, and dropping funnel Stir while heating. When it was confirmed that trimethylolpropane was completely dissolved, stirring was continued while reducing the pressure to 10 Torr with a vacuum pump, and water contained in the alcohol was removed over 1 hour. While introducing nitrogen, the pressure was returned to atmospheric pressure, and when the temperature inside the reaction vessel fell below 80 ° C., 250 parts of ethyl acetate was added through a dropping funnel over 30 minutes. 564.54 parts of xylylene diisocyanate were introduced into a reaction vessel equipped with a newly prepared stirrer, nitrogen gas inlet tube, cooling condenser, and dropping funnel, while maintaining the internal temperature at 60 ° C. to 70 ° C. The ethyl acetate solution was slowly added dropwise over 1 hour. The trimethylolpropane adhering to the inside of the suitable funnel was washed with 50 parts of ethyl acetate, and the washed ethyl acetate solution was added to the reaction vessel. Stirring was continued at 70 ° C. for 3 hours after the dropwise addition to obtain a 70% ethyl acetate adduct (TMP-3XDI) having a molecular weight of 698 obtained by adding 3 moles of metaxylylene diisocyanate to trimethylolpropane.

(Curing agent for adhesive a)
TMP-3XDI obtained in Production Example 15 was used as a curing agent a.

(Curing agent for adhesive b)
Metaxylylene diisocyanate (mXDI) manufactured by Mitsui Chemicals was used as the curing agent b.

(Examples 1-8 Comparative Examples 1-5 Manufacturing Method of Adhesive)
The polyester polyol obtained by the above production method is diluted with ethyl acetate to obtain a resin solution having a non-volatile content of 50%. Further, a curing agent is blended as shown in Table 1 and used in the coating method 1 described later. An adhesive was obtained.

(Coating method)
Using a bar coater, the solvent-type adhesive was applied to a PET film (“E-5100” manufactured by Toyobo Co., Ltd.) having a thickness of 12 μm so that the coating amount was 5.0 g / m ² (solid content). Then, the diluted solvent was volatilized and dried with a drier set at a temperature of 70 ° C., and the adhesive surface of the PET film on which the adhesive was applied and a 70 μm thick CPP film (“ZK93KM” manufactured by Toray Industries, Inc.) Lamination was performed to prepare a composite film having a layer structure of PET film / adhesive layer / CPP film. Subsequently, this composite film was aged at 40 ° C. for 3 days, and the adhesive was cured to obtain the oxygen barrier film of the present invention.

(Evaluation method)
(1) Adhesive strength The oxygen barrier film having finished aging is cut into a width of 15 mm in parallel with the coating direction, and between the PET film and the CPP film using a Tensilon universal testing machine manufactured by Orientec Co., Ltd. The tensile strength at the time of peeling by the 180 ° peeling method was defined as the adhesive strength at an atmosphere temperature of 25 ° C. and a peeling speed of 300 mm / min. The unit of adhesive strength was N / 15 mm.

(2) Oxygen transmission rate The oxygen barrier film after the aging was completed at 23 ° C. and 0% humidity (RH) according to JIS-K7126 (isobaric method) using an oxygen transmission rate measuring device OX-TRAN2 / 21MH manufactured by Mocon. ) And 90% RH.

(Reference example)
The oxygen permeability measurement result of a PET (biaxially stretched polyethylene terephthalate) film (E-5100 manufactured by Toyobo Co., Ltd.) having a thickness of 12 μm is shown.

The results are shown in Table 8 and Table 9.

As a result, the oxygen barrier films using the adhesives of Examples 1 to 8 all had an oxygen permeability of 35 cc / m ² · day · atm or less and excellent adhesive strength.
On the other hand, the oxygen barrier film using the adhesive of Comparative Example 1 had a low permacol value of the polyester polyol used, so the oxygen permeability was> 35 cc / m ² · day · atm. The comparative example did not dissolve in ethyl acetate because the residue of the main agent excluding the hydroxyl group was 60 or more.
In Comparative Example 3, although the permacol value of the polyester polyol is in the range of 44 to 60, the oxygen permeation rate greatly exceeds 35 cc / m ² · day · atm because the permacol value of the cured product is as low as 50 to 60. As a result.
In Comparative Examples 4 and 5, the polyester polyol has a permacol value of 44 or less and the cured product has a low permacol value of 50 to 60, so that the oxygen transmission rate greatly exceeds 35 cc / m ² · day · atm. became.

  Since the adhesive of the present invention has an oxygen barrier property, in addition to the adhesive for film lamination for the packaging material, for example, an adhesive for a protective film for solar cells, an adhesive for a gas barrier substrate for display elements, etc. It can be suitably used for applications that require oxygen barrier properties, such as adhesives for materials, adhesives for building materials, and adhesives for industrial materials.

Claims (8)

A gas barrier cured product obtained by curing a resin composition for a gas barrier cured product containing a polyester polyol (A) having two or more hydroxyl groups in a molecule and an isocyanate compound (B) as a functional group,
The permacol value of the residue excluding the terminal hydroxyl group of the polyester polyol (A) is in the range of 44-60,
The permacol value per mole of the resin composition for gas barrier cured product is 70 or more ,
A gas barrier cured product comprising bishydroxyethylbenzene as a glycol component constituting the polyester polyol (A). The gas barrier cured product according to claim 1, wherein 1,2-naphthalenedicarboxylic acid or diphenic acid is used as the polyvalent carboxylic acid component constituting the polyester polyol (A). Metaxylene diisocyanate is added to a resin composition for a gas barrier cured product having a hydroxyl value of 80 or more using 1,3-bishydroxyethylbenzene as a glycol component constituting the polyester polyol (A) and phthalic acid as a polyvalent carboxylic acid component. The gas barrier cured product according to claim 1 or 2, which is obtained by using an adduct of trimethylolpropane and trimethylolpropane as an essential component. Metaxylene diisocyanate is added to a resin composition for a gas barrier cured product having a hydroxyl value of 80 or more using ethylene glycol as the glycol component constituting the polyester polyol (A) and 1,2-naphthalenedicarboxylic acid as the polyvalent carboxylic acid component. The gas barrier cured product according to any one of claims 1 to 3, which is obtained by using an adduct of trimethylolpropane and trimethylolpropane as an essential component. The gas barrier cured product according to claim 1, wherein the hydroxyl value of the polyester polyol (A) is 80 or more. The gas barrier cured product according to claim 1, wherein the polyester polyol (A) is amorphous. A gas barrier adhesive using the gas barrier cured product according to claim 1. The gas barrier adhesive according to claim 7, which is used as an adhesive for film lamination.