Polyester polyisocyanate, polyester polyisocyanate composition, adhesives, layering products, and packaging materials.

Abstract

Provided are a gas barrier laminate film and packaging material that are a transparent film usable as a transparent barrier film for packaging materials mainly for food, and electronic materials for solar cells, display elements, etc., and that have an excellent gas barrier function and are resistant to bending. This polyester polyisocyanate (B) is a reaction product of a polyester which is a polycondensation product of a polycarboxylic acid or a derivative thereof (I-B) and a polyhydric alcohol (II-B), with an isocyanate compound, wherein the polycarboxylic acid or a derivative thereof (I-B) contains an aliphatic polycarboxylic acid having eight or less carbon atoms at a portion excluding a carboxyl group, or a derivative thereof (I-B-i), and an aromatic polycarboxylic acid or a derivative thereof (I-B-ii), and the polyhydric alcohol (II-B) contains an aliphatic polyhydric alcohol (II-B-i) having eight or less carbon atoms.

Description

Polyester polyisocyanate, polyester polyisocyanate composition, adhesive, laminate, packaging material

[0001] The present invention relates to a polyester polyisocyanate, a polyester polyisocyanate composition, an adhesive, a laminate, and a packaging material.

[0002] Packaging materials for foods, beverages, etc. are required to have a wide range of functions, such as strength, resistance to breakage, retort resistance, and heat resistance, as well as excellent transparency so that the contents can be checked, in order to protect the contents from various processes such as distribution, storage (e.g., refrigeration), and heat sterilization. On the other hand, when sealing bags by heat sealing, unstretched polyolefin films, which have excellent thermal processability, are essential, but unstretched polyolefin films lack many of the functions required for packaging.

[0003] For these reasons, composite flexible films combining different polymer materials are widely used as packaging materials. Generally, composite flexible films are composed of a thermoplastic film layer or the like serving as an outer layer that protects products and has various functions, and a thermoplastic film layer or the like serving as a sealant layer. Known methods for bonding these layers include a method in which a three-layer melt extrusion of a thermoplastic for the outer layer, an adhesive, and a thermoplastic for the sealant layer is performed to form an unstretched laminated sheet, and then stretching the resultant sheet (see, for example, Patent Document 1), and a dry lamination method in which an adhesive is applied to a laminate film layer and the sealant layer is bonded to produce a multilayer film (see, for example, Patent Document 2).

[0004] In recent years, there has been a demand for even higher functionality in multilayer films, including oxygen barrier properties that prevent the intrusion of oxygen from outside to suppress oxidation, carbon dioxide barrier properties, and barrier properties against various aroma components. Furthermore, as one method for extending the shelf life of food, the inclusion of an inert gas, an ethyl alcohol evaporant, or ethyl alcohol vapor in the packaging together with the food to prevent the growth of microorganisms and mold that cause food deterioration and spoilage is widely practiced. In such packaging, a barrier function that prevents the leakage of the inert gas or ethyl alcohol is also required to maintain the quality of the food. Known methods for imparting a barrier function to a multilayer film include coating various films (polyester-based resins such as polyethylene terephthalate (hereinafter abbreviated as PET), polyamide resins, and oriented polyolefin resins) used on the outer layer to impart a barrier function; imparting a laminating function to an adhesive used during lamination; and using a film vapor-deposited with silica, alumina, aluminum, or the like.

[0005] When imparting alcohol barrier functionality to the outer layer film by coating, vinylidene chloride has often been used as a barrier coating material because of its high oxygen and water vapor barrier properties (i.e., it easily hinders mass transfer). However, this has problems such as the generation of dioxins during the burning process before disposal, and yellowing when exposed to light. Furthermore, polyvinyl alcohol resins and ethylene-polyvinyl alcohol copolymers, which have oxygen barrier functionality, have the problem that their barrier properties deteriorate further under high humidity conditions, which causes the resin to swell.

[0006] The method of adding gas barrier properties to the adhesive used during lamination has the advantage that it allows the production of gas barrier multilayer films without using special films with added gas barrier properties, thanks to the processes and configurations required for producing laminated films. On the other hand, the flexible molecular structure required for adhesives generally has high gas permeability. Therefore, there is often a trade-off between adhesive ability and gas barrier properties, and resolving this issue is becoming increasingly technically difficult.

[0007] As containers using such gas barrier laminate films, for example, Patent Documents 3 and 4 describe gas barrier laminate films in which a thermoplastic plastic film layer or the like serving as an outer layer and a thermoplastic plastic film layer serving as a sealant layer are bonded together with an epoxy resin composition comprising an epoxy resin and an epoxy resin curing agent.

[0008] However, epoxy-based adhesives are rarely used as laminating adhesives for multilayer films, while reactive systems of polyester polyol and polyisocyanate are most widely used. Therefore, when switching from general-purpose adhesives, there has been a strong demand for non-epoxy adhesives from the viewpoints of solvent compatibility and compatibility with residual materials. Furthermore, in the case of bag-shaped containers containing food, in particular, non-epoxy materials have been required from the viewpoint of chemical safety.

[0009] Methods using films vapor-deposited with silica, alumina, aluminum, etc. also do not provide perfect gas barrier properties because the vapor-deposited layer usually has vapor deposition defects. Furthermore, because the vapor-deposited layer is an inorganic thin film, it has low flexibility, and cracks can occur, particularly when the film is twisted or bent, resulting in a decrease in barrier performance. Vapor-deposited films are originally used for applications requiring a high barrier, so the unstable barrier function poses a major practical problem from the perspective of quality control of the contents.

[0010] Furthermore, as the thickness of the vapor-deposited layer increases, cracks tend to occur more easily during winding. Increasing the thickness of the vapor-deposited layer increases the technical difficulty and the required cost, making it difficult to improve the barrier function simply by thickening the vapor-deposited layer. Therefore, to impart a higher gas barrier function, measures such as laminating multiple transparent vapor-deposited film layers, alternating lamination of vapor-deposited layers and overcoat layers, or using other barrier films in combination are required, resulting in a complex layer structure and an expensive film.

[0011] Japanese Patent Publication No. 2006-341423 Japanese Patent Publication No. 2003-13032 Japanese Patent Publication No. 4092549 Japanese Patent Publication No. 4366563

[0012] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas barrier multilayer film and packaging material which is a transparent film that can be used as a packaging material, mainly for food products, or as a transparent barrier film for electronic materials such as solar cells and display elements, and which has excellent gas barrier function and is also strong against bending treatment.

[0013] The present invention relates to a polyester polyisocyanate (B) that is a reaction product of a polyester that is a polycondensate of a polycarboxylic acid or a derivative thereof (IB) and a polyhydric alcohol (II-B), and an isocyanate compound, in which the polycarboxylic acid or derivative thereof (IB) comprises an aliphatic polycarboxylic acid or derivative thereof (IB-i) having 8 or less carbon atoms, excluding carboxyl groups, and an aromatic polycarboxylic acid or derivative thereof (IB-ii), and the polyhydric alcohol (II-B) comprises an aliphatic polyhydric alcohol (II-B-i) having 8 or less carbon atoms.

[0014] The present invention further relates to a polyisocyanate composition containing the polyester polyisocyanate (B), an adhesive using the polyisocyanate composition, a laminate obtained by using the adhesive, and a packaging material obtained by using the laminate.

[0015] The polyester polyisocyanate (B) of the present invention can provide an adhesive having excellent gas barrier properties, and can also provide a gas barrier multilayer film and a packaging material that not only have excellent gas barrier function but also are strong against bending treatment.

[0016] The present invention provides a polyester polyisocyanate (B) that is a reaction product of a polyester that is a polycondensate of a polycarboxylic acid or a derivative thereof (IB) and a polyhydric alcohol (II-B), and an isocyanate compound, in which the polycarboxylic acid or derivative thereof (IB) comprises an aliphatic polycarboxylic acid or derivative thereof (IB-i) having 8 or less carbon atoms, excluding carboxyl groups, and an aromatic polycarboxylic acid or derivative thereof (IB-ii), and the polyhydric alcohol (II-B) comprises an aliphatic polyhydric alcohol (II-B-i) having 8 or less carbon atoms.

[0017] The present invention also relates to a polyisocyanate composition, an adhesive, a laminate, and a packaging material using the polyester polyisocyanate (B).The configuration of the present invention will be described in detail below.

[0018] 1. Polyol Composition The polyol composition used in the present invention is one component of a two-component adhesive used together with a polyisocyanate composition. The polyol composition used in the present invention will be described in detail below.

[0019] <Polyol> The polyol composition used in the present invention substantially contains a resin (polyol) having two or more hydroxyl groups. Because the time required for synthesis is short and handling is easy, it is preferable to use a polyol having a number average molecular weight of 300 to 3,000, more preferably 350 to 1,000, and even more preferably 350 to 950. In the present invention, the number average molecular weight (Mn) is a value measured by gel permeation chromatography (GPC) under the following conditions:

[0020] Measurement equipment: HLC-8220 GPC manufactured by Tosoh Corporation Column: TSK-GUARDCOULUMN SuperHZ-L manufactured by Tosoh Corporation + TSK-GEL SuperHZM-M x 4 manufactured by Tosoh Corporation Detector: RI (differential refractometer) Data processing: Multistation GPC-8020 model II manufactured by Tosoh Corporation Measurement conditions: Column temperature: 40°C Solvent: tetrahydrofuran Flow rate: 0.35 ml / min Standard: monodisperse polystyrene Sample: 100 μl of a tetrahydrofuran solution of 0.2% by mass (in terms of resin solids) filtered through a microfilter

[0021] Examples of polyols include polyols having a polyester skeleton, polyols having a polyurethane skeleton, polyols having a polyether skeleton, and polyols having an acrylic skeleton. In order to impart gas barrier properties to the adhesive described below and to make the gas barrier multilayer film described below resistant to bending treatment (hereinafter also referred to as flex resistance), it is preferable to contain a polyol (A) having a polyester skeleton that is a polycondensate of a polycarboxylic acid or its derivative (IA) and a polyhydric alcohol (II-A). Hereinafter, the polyol (A) having a polyester skeleton will also be simply referred to as polyester polyol (A).

[0022] Examples of the polyester polyol (A) used in the present invention include, but are not limited to, polyester polyols (A) obtained by using an aliphatic polycarboxylic acid or its derivative (I-A-i) having 8 or less carbon atoms, excluding carboxyl groups, as the polycarboxylic acid or its derivative (I-A); polyester polyols (A) obtained by using an aromatic polycarboxylic acid or its derivative (I-A-ii) as the polycarboxylic acid or its derivative (I-A); polyester polyols (A) obtained by using an aliphatic polycarboxylic acid or its derivative (I-A-i) having 8 or less carbon atoms, excluding carboxyl groups, as the polycarboxylic acid or its derivative (I-A), and an aromatic polycarboxylic acid or its derivative (I-A-ii) in combination as the polycarboxylic acid or its derivative (I-A); and the like. Furthermore, the polyester polyol (A) used in the present invention preferably contains an aliphatic polycarboxylic acid (II-A-i) having 8 or less carbon atoms as the polyhydric alcohol (II-A).

[0023] In the following, an aliphatic polycarboxylic acid or a derivative thereof (IA-i) having 8 or less carbon atoms excluding carboxyl groups will also be referred to as a polycarboxylic acid (IA-i), an aromatic polycarboxylic acid or a derivative thereof (IA-ii) will also be referred to as a polycarboxylic acid (IA-ii), and an aliphatic polyhydric alcohol (II-A-i) having 8 or less carbon atoms will also be referred to as a polyhydric alcohol (II-A-i).

[0024] (Polycarboxylic Acid or Derivative thereof (IA)) (Polycarboxylic Acids (IA-i)) As the polycarboxylic acid (IA-i) used in the synthesis of the polyester polyol (A), conventionally known polycarboxylic acids can be used without any particular limitation. Specific examples include oxalic acid, malonic acid, ethylmalonic acid, dimethylmalonic acid, succinic acid, dimethylsuccinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-cyclohexenedicarboxylic acid, 3-methyl-4-cyclohexene-1,2-dicarboxylic acid, and anhydrides and methyl esters thereof, which can be used alone or in combination of two or more.

[0025] (Polycarboxylic Acids (I-A-ii)) As the polycarboxylic acid (I-A-ii) used in the synthesis of the polyester polyol (A), conventionally known polycarboxylic acids can be used without any particular limitation. Specific examples include orthophthalic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, and anhydrides and methyl esters thereof, which can be used alone or in combination of two or more.

[0026] It is preferable to use orthophthalic acid, terephthalic acid, isophthalic acid, or anhydrides thereof, and it is more preferable to use orthophthalic acid or orthophthalic anhydride in order to improve the gas barrier properties and adhesion of the adhesive described below. The reason why the gas barrier properties of the adhesive are excellent when orthophthalic acid or orthophthalic anhydride is used is presumed to be because the rotation of the polyester chain obtained by using orthophthalic acid or its anhydride is suppressed. The reason why the adhesion is excellent is presumed to be because the polyester chain is asymmetric, exhibiting amorphous nature and imparting sufficient substrate adhesion.

[0027] (Polycarboxylic Acids (I-A-iii)) The polycarboxylic acid or its derivative (I-A) used in the synthesis of the polyester polyol (A) of the present invention may contain a polycarboxylic acid (I-A-iii) other than the polycarboxylic acids (I-A-i) and the polycarboxylic acids (I-A-ii). Examples of the polycarboxylic acid (I-A-iii) include polycarboxylic acids having more than 8 carbon atoms excluding the carboxyl group, such as dodecanedicarboxylic acid, and these may be used alone or in combination of two or more. When the polycarboxylic acid (I-A-iii) is used in combination, the amount is preferably kept to 10% by mass or less, more preferably 5% by mass or less, of the total amount of the polycarboxylic acid or its derivative (I-A).

[0028] When emphasis is placed on the flex resistance of the cured coating film of the adhesive described below, the proportion of the polycarboxylic acid (IA-i) in the polycarboxylic acid or its derivative (IA) is preferably 100 mol %. When emphasis is placed on the gas barrier properties of the cured coating film of the adhesive described below, the proportion of the polycarboxylic acid (IA-ii) in the polycarboxylic acid or its derivative (IA) is preferably 100 mol %. The combined use of the polycarboxylic acid (IA-i) and the polycarboxylic acid (IA-ii) is preferred because the cured coating film of the adhesive described below has excellent gas barrier properties and flex resistance. The compounding ratio (molar ratio) of the polycarboxylic acid (IA-i) to the polycarboxylic acid (IA-ii) is, for example, 1:9 to 9:1, more preferably 2:8 to 8:2.

[0029] (Polyhydric Alcohol (II-A)) (Polyhydric Alcohol (II-A-i)) As the polyhydric alcohol (II-A-i) used in the synthesis of the polyester polyol (A), conventionally known polyhydric alcohols can be used without particular limitation. Specific examples include ethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, cyclohexanedimethanol, dimethylbutanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,4-butanetriol, and pentaerythritol, and these can be used alone or in combination of two or more. Of these, ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and the like are preferred.

[0030] (Polyhydric Alcohol (II-A-ii)) The polyhydric alcohol (II-A) used in the synthesis of the polyester polyol (A) may contain a polyhydric alcohol (II-A-ii) other than the polyhydric alcohol (II-A-i). Examples of the polyhydric alcohol (II-A-ii) include tetraethylene glycol, tripropylene glycol, dipentaerythritol, hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, bisphenol F, and tetramethylbiphenol, and these may be used alone or in combination of two or more. When the polyhydric alcohol (II-A-ii) is used in combination, its amount is preferably kept to 10% by mass or less, and more preferably kept to 5% by mass or less, of the total amount of the polyhydric alcohol (II-A).

[0031] (Polyester polyol (A)) The number average molecular weight of the polyester polyol (A) is preferably from 300 to 3,000, more preferably from 350 to 1,000, and even more preferably from 350 to 950. This makes it possible to obtain an adhesive having excellent adhesive properties and gas barrier properties.

[0032] The hydroxyl value of the polyester polyol (A) is preferably 20 mgKOH / g or more and 400 mgKOH / g or less. If the hydroxyl value is less than 20 mgKOH / g, the viscosity of the polyester polyol (A) will be high, and good coatability may not be obtained. If the hydroxyl value exceeds 400 mgKOH / g, the crosslink density of the cured coating film will be too high, and good adhesive strength may not be obtained. The hydroxyl value of the polyester polyol (A) can be measured by the hydroxyl value measurement method described in JIS-K0070.

[0033] The acid value of the polyester polyol (A) is preferably 200 mgKOH / g or less. If the acid value exceeds 200 mgKOH / g, the reaction with the polyisocyanate may proceed too quickly, making it difficult to obtain good coating suitability. The lower limit of the acid value of the polyester polyol (A) is not particularly limited, and may be 0 mgKOH / g. The acid value of the polyester polyol (A) can be measured by the acid value measurement method described in JIS-K0070.

[0034] To obtain good adhesiveness, the glass transition temperature of the polyester polyol (A) is preferably 10° C. or lower, and more preferably 5° C. or lower. There is no particular restriction on the lower limit of the glass transition temperature, but as an example, it is −60° C. or higher, and more preferably −50° C. or higher. The glass transition temperature of the polyester polyol (A) can be measured using a differential scanning calorimeter.

[0035] The polyester polyol (A) used in the present invention is preferably linear. In this specification, the term "linear polyester polyol (A)" means that the raw materials of the polyester polyol (polycarboxylic acid or its derivative (IA) and polyhydric alcohol (II-A)) are all compounds having two reactive groups. For example, a polyester polyol prepared using a bifunctional alcohol having a branched alkyl group, such as neopentyl glycol, as the polyhydric alcohol (II-A) is included in the linear polyester polyol. This suppresses an increase in the viscosity of the polyester polyol, making it possible to obtain an adhesive with excellent coatability.

[0036] <Polyol Composition> The polyol composition used in the present invention substantially contains a resin (polyol) having two or more hydroxyl groups, preferably the polyester polyol (A) described above, and may further contain other components, such as a low-molecular-weight alcohol, an organic solvent, a viscosity modifier, a silane coupling agent, a defoaming agent, and a tackifier, as needed.

[0037] Examples of low molecular weight alcohols include ethylene glycol, glycerin, 1,3-butanediol, 1,4-butanediol, 2-methylpentane-2,4-diol, 3-methyl-1,5-pentanediol, diacetin, propyl caprylate, castor oil, polyethylene glycol, and polypropylene glycol.

[0038] Examples of the organic solvent include toluene, xylene, methylene chloride, tetrahydrofuran, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, acetone, methyl ethyl ketone (MEK), cyclohexanone, toluene, xylol, n-hexane, and cyclohexane.

[0039] Examples of viscosity modifiers include dimethyl phthalate, dibutyl phthalate, dimethoxyethyl phthalate, dioctyl phthalate, diphenyl phthalate, triacetin, propyl dicaprylate, and propylene carbonate.

[0040] Examples of the silane coupling agent include aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; epoxysilanes such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and glycidoxyoctyltrimethoxysilane; vinyltris(β-methoxyethyl)silane; Examples of suitable silane coupling agents include vinyl silanes such as vinyltriethoxysilane, vinyltrimethoxysilane, octenyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and methacryloxyoctyltrimethoxysilane; polymeric epoxy silanes in which multiple alkoxysilyl groups and multiple epoxy groups have been introduced into the polymer backbone, and polymeric amino silanes in which multiple alkoxysilyl groups and multiple amino groups have been introduced into the polymer backbone; and polymeric silane coupling agents such as hexamethyldisilazane, γ-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane. These silane coupling agents can be used alone or in combination of two or more.

[0041] Any known antifoaming agent can be used without any particular limitation. Examples include dimethylpolysiloxane, silicone-based antifoaming agents in which some of the methyl groups of dimethylpolysiloxane have been modified with carbinol groups, polyether groups, alkyl groups having two or more carbon atoms, epoxy groups, amino groups, or the like, long-chain alcohols such as octyl alcohol, and sorbitan derivatives such as sorbitan monooleate.

[0042] Examples of tackifiers include rosin-based or rosin ester-based tackifiers, terpene-based or terpene phenol-based tackifiers, saturated hydrocarbon resins, coumarone-based tackifiers, coumarone-indene-based tackifiers, styrene resin-based tackifiers, xylene resin-based tackifiers, phenol resin-based tackifiers, petroleum resin-based tackifiers, etc. These may be used alone or in combination of two or more.

[0043] 2. Polyisocyanate Composition The polyisocyanate composition of the present invention is one component of a two-component adhesive used together with a polyol composition, and contains the polyester polyisocyanate (B) of the present invention as an essential component. The polyester polyisocyanate (B) and the polyisocyanate composition of the present invention are described in detail below.

[0044] <Polyester Polyisocyanate (B)> The polyester polyisocyanate (B) of the present invention is used as one component of the polyisocyanate composition of an adhesive containing a polyol composition and a polyisocyanate composition. The polyester polyisocyanate (B) is a reaction product of a polyester, which is a polycondensate of a polycarboxylic acid or its derivative (IB) and a polyhydric alcohol (II-B), and an isocyanate compound. The polyester polyisocyanate (B) contains two or more isocyanate groups per molecule. The polycarboxylic acid or its derivative (IB) includes an aliphatic polycarboxylic acid or its derivative (IB-i) having 8 or fewer carbon atoms, excluding carboxyl groups, and an aromatic polycarboxylic acid or its derivative (IB-ii). The polyhydric alcohol (II-B) includes an aliphatic polyhydric alcohol (II-B-i) having 8 or fewer carbon atoms.

[0045] In the following, an aliphatic polycarboxylic acid or a derivative thereof (I-Bi-i) having 8 or less carbon atoms excluding carboxyl groups will also be referred to as a polycarboxylic acid (I-Bi-i), an aromatic polycarboxylic acid or a derivative thereof (I-B-ii) will also be referred to as a polycarboxylic acid (I-B-ii), and an aliphatic polyhydric alcohol (II-Bi) having 8 or less carbon atoms will also be referred to as a polyhydric alcohol (II-Bi).

[0046] (Polycarboxylic Acid or Derivative thereof (IB)) As the polycarboxylic acid (IB-i) used in the synthesis of the polyester polyisocyanate (B) of the present invention, conventionally known polycarboxylic acids can be used without any particular limitation. Specifically, the same polycarboxylic acids as those exemplified as the polycarboxylic acid (IA-i) can be used, and they can be used alone or in combination of two or more kinds.

[0047] (Polycarboxylic Acids (IB-ii)) As the polycarboxylic acid (IB-ii) used in the synthesis of the polyester polyisocyanate (B) of the present invention, conventionally known polycarboxylic acids can be used without any particular limitation. Specifically, the same polycarboxylic acids as those exemplified as the polycarboxylic acid (IA-ii) can be used, and they can be used alone or in combination of two or more.

[0048] It is preferable to use orthophthalic acid, terephthalic acid, isophthalic acid, or anhydrides thereof, and it is more preferable to use orthophthalic acid or orthophthalic anhydride in order to improve the gas barrier properties and adhesion of the adhesive described below. The reason why the gas barrier properties of the adhesive are excellent when orthophthalic acid or orthophthalic anhydride is used is presumed to be because the rotation of the polyester chain obtained by using orthophthalic acid or its anhydride is suppressed. The reason why the adhesion is excellent is presumed to be because the polyester chain is asymmetric, exhibiting amorphous nature and imparting sufficient substrate adhesion.

[0049] (Polycarboxylic Acids (I-B-iii)) The polycarboxylic acid or derivative thereof (IB) used in the synthesis of the polyester polyisocyanate (B) of the present invention may contain a polycarboxylic acid (IB-iii) other than the polycarboxylic acids (IB-i) and (IB-ii). Examples of the polycarboxylic acid (IB-iii) include polycarboxylic acids having more than 8 carbon atoms excluding the carboxyl group, such as dodecanedicarboxylic acid, and these may be used alone or in combination of two or more. When the polycarboxylic acid (IB-iii) is used in combination, its amount is preferably kept to 10% by mass or less, and more preferably 5% by mass or less, of the total amount of the polycarboxylic acid or derivative thereof (IB).

[0050] The blending ratio of the polycarboxylic acids (I-Bi-i) and (I-B-ii) may be adjusted appropriately depending on the required gas barrier properties and flex resistance. The blending ratio (molar ratio) of the polycarboxylic acids (I-Bi-i) and (I-B-ii) is, for example, 1:9 to 9:1, and more preferably 2:8 to 8:2.

[0051] (Polyhydric Alcohol (II-B)) (Polyhydric Alcohol (II-B-i)) As the polyhydric alcohol (II-B-i) used in the synthesis of the polyester polyisocyanate (B) of the present invention, any conventionally known alcohol can be used without any particular limitation. Specifically, the same alcohols as those exemplified as the polyhydric alcohol (II-A-i) can be used, and they can be used alone or in combination of two or more. Among these, ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, etc. are preferred.

[0052] (Polyhydric Alcohol (II-B-ii)) The polyhydric alcohol (II-B) used in the synthesis of the polyester polyisocyanate (B) of the present invention may contain a polyhydric alcohol (II-B-ii) other than the polyhydric alcohol (II-B-i). When the polyhydric alcohol (II-B-ii) is used in combination, the amount of the polyhydric alcohol (II-B-ii) is preferably kept to 10% by mass or less, and more preferably 5% by mass or less, of the total amount of the polyhydric alcohol (II-B).

[0053] (Isocyanate Compound) The isocyanate compound used in the synthesis of the polyester polyisocyanate (B) of the present invention is not particularly limited, and known isocyanate compounds can be used, for example, aliphatic diisocyanates such as butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, and m-tetramethylxylylene diisocyanate;

[0054] Alicyclic diisocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, methylcyclohexane diisocyanate, isopropylidenedicyclohexyl-4,4'-diisocyanate, and norbornane diisocyanate;

[0055] Examples of aromatic diisocyanates include 1,5-naphthalene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and tolylene diisocyanate.

[0056] Furthermore, oligomers of these diisocyanates, adduct-type polyisocyanates, nurate-type polyisocyanates, allophanate-type polyisocyanates, etc. may also be used.

[0057] Because of their excellent gas barrier properties and adhesiveness, it is preferable to use an isocyanate compound having an aromatic ring in the molecule. Conventional isocyanate compounds having an aromatic ring in the molecule can be used without particular limitation. Specific examples include isocyanate monomers such as xylylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and tetramethylxylene diisocyanate; compounds in which a portion of the isocyanate groups of these isocyanate monomers has been modified with carbodiimide; oligomers; allophanate compounds; nurate compounds; and reaction products of these isocyanates with compounds having two or more active hydrogen groups. Examples of compounds having two or more active hydrogen groups include trimethylolpropane, glycerol, erythritol, pentaerythritol, sorbitol, diethanolamine, triethanolamine, and alkylene oxide adducts of these compounds.

[0058] Among these, at least one selected from the group consisting of xylylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 4,4'-diphenylmethane diisocyanate is preferred.

[0059] The proportion of the isocyanate compound having an aromatic ring relative to the total amount of isocyanate compounds used in the synthesis of the polyester polyisocyanate (B) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The total amount of the isocyanate compounds used in the synthesis of the polyester polyisocyanate (B) may be isocyanate compounds having an aromatic ring.

[0060] (Intermediate Polyester) The polyester, which is an intermediate of the polyester polyisocyanate (B), can be obtained by reacting the above-mentioned polycarboxylic acid or its derivative (IB) with the polyhydric alcohol (II-B).

[0061] The intermediate polyester of polyester polyisocyanate (B) is preferably linear. In this specification, the term "linear intermediate polyester of polyester polyisocyanate (B)" means that the raw materials of the polyester polyol (polycarboxylic acid or its derivative (II-A) and polyhydric alcohol (II-B)) are all compounds having two reactive groups. For example, a polyester polyol prepared using a bifunctional alcohol having a branched alkyl group, such as neopentyl glycol, as the polyhydric alcohol (II-B) is included in the linear chain. This suppresses an increase in viscosity of the polyester polyisocyanate, which is the final product, and enables the production of an adhesive with excellent coatability.

[0062] (Polyester Polyisocyanate (B)) The polyester polyisocyanate (B) of the present invention can be obtained by reacting an isocyanate compound with the terminal of a polyester that is a polycondensate of the above-mentioned polycarboxylic acid or its derivative (IB) and a polyhydric alcohol (II-B).

[0063] <Polyisocyanate Composition> The polyisocyanate composition of the present invention contains the above-described polyester polyisocyanate (B) as an essential component. It may further contain an isocyanate compound other than the polyester polyisocyanate (B) as long as the effects of the present invention are not impaired.

[0064] Examples of the isocyanate compound other than the polyester polyisocyanate (B) include aliphatic diisocyanates such as butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, and m-tetramethylxylylene diisocyanate;

[0065] Alicyclic diisocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, methylcyclohexane diisocyanate, isopropylidenedicyclohexyl-4,4'-diisocyanate, and norbornane diisocyanate;

[0066] Examples of aromatic diisocyanates include 1,5-naphthalene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and tolylene diisocyanate.

[0067] Furthermore, oligomers of these diisocyanates, adduct-type polyisocyanates, nurate-type polyisocyanates, allophanate-type polyisocyanates, etc. may also be used.

[0068] When the polyester polyisocyanate (B) is used in combination with an isocyanate compound other than the polyester polyisocyanate (B), the content of the polyester polyisocyanate (B) relative to the total of these is preferably 50% by mass or more, and more preferably 60% by mass or more.

[0069] When an isocyanate compound other than the polyester polyisocyanate (B) is used, it is preferable to use a polyisocyanate having an aromatic ring, more preferably at least one selected from the group consisting of xylylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 4,4'-diphenylmethane diisocyanate.

[0070] As the isocyanate compound other than the polyester polyisocyanate (B), an isocyanate compound remaining without reacting with the intermediate polyester when preparing the polyester polyisocyanate (B) may be used as it is, or may be added when preparing the polyisocyanate composition.

[0071] The polyisocyanate composition may further contain an organic solvent and a viscosity modifier, which may be the same as those used in the polyol composition.

[0072] 3. Adhesive The adhesive of the present invention is a two-component adhesive containing a polyol composition and the polyisocyanate composition of the present invention, and is suitable for film lamination applications. The adhesive of the present invention may be used in either a solvent-based or solventless form.

[0073] In this specification, the term "solvent-based adhesive" refers to a form used in a method in which the adhesive is applied to a substrate, heated in an oven or the like to volatilize the organic solvent in the coating, and then laminated to another substrate, a so-called dry lamination method. Either one or both of the polyol composition and the polyisocyanate composition contains the organic solvent described above. In the case of a solvent-based adhesive, the solvent used as a reaction medium during production of the constituent components of the polyol composition or polyisocyanate composition may also be used as a diluent during coating.

[0074] A solventless adhesive is a form used in a method in which an adhesive is applied to a substrate and then bonded to another substrate without heating in an oven or the like to volatilize the solvent, a method known as non-solvent lamination. Both the polyol composition and the polyisocyanate composition are substantially free of the organic solvents described above. A polyol composition or polyisocyanate composition is considered to be substantially free of organic solvents if trace amounts of organic solvent remain in the polyol composition or polyisocyanate composition due to incomplete removal of the organic solvent used as a reaction medium during the production of the polyol composition or polyisocyanate composition's components or raw materials. Furthermore, if the polyol composition contains a low-molecular-weight alcohol, the low-molecular-weight alcohol reacts with the isocyanate composition to become part of the coating film, eliminating the need for volatilization after application. Therefore, such a form is also considered a solventless adhesive.

[0075] The adhesive of the present invention is used by mixing the polyol composition and the polyisocyanate composition immediately before application to a substrate. The polyol composition and the polyisocyanate composition are preferably blended so that the equivalent ratio [NCO] / [OH] of the hydroxyl groups contained in the polyol composition to the isocyanate groups contained in the polyisocyanate composition is 0.5 to 4. If the [NCO] / [OH] ratio exceeds 4, excess isocyanate groups may bleed out from the cured coating film of the adhesive, and if it is below 0.5, the adhesive strength may be insufficient.

[0076] The adhesive of the present invention may contain various additives such as inorganic fillers such as silica, alumina, aluminum flakes, and glass flakes; coupling agents such as silane coupling agents and titanium coupling agents; antioxidants, heat stabilizers, UV absorbers, antistatic agents, lubricants, antiblocking agents, colorants, and crystal nucleating agents. In order to adjust the glass transition temperature of the cured coating film of the adhesive, various thermoplastic resins such as acrylic resins, ketone resins, epoxy resins, and polyester resins may be blended. These various additives and thermoplastic resins may be added in advance to either or both of the polyol composition and the polyisocyanate composition, or may be added when the polyol composition and the polyisocyanate composition are mixed.

[0077] 4. Laminates The laminate of the present invention can be obtained, for example, by bonding multiple films together using the adhesive of the present invention by a dry lamination method or a non-solvent lamination method. The laminated laminate has excellent gas barrier properties and can be used as a gas barrier laminate. There are no particular restrictions on the film used, and a film can be appropriately selected depending on the application. For example, for food packaging, polyolefin films such as polyethylene terephthalate (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: biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, etc. can be mentioned.

[0078] The film may be one that has been subjected to a stretching treatment. A typical stretching method involves melt-extruding a resin into a sheet using an extrusion film-forming method or the like, followed by simultaneous biaxial stretching or sequential biaxial stretching. In the case of sequential biaxial stretching, it is common to first perform longitudinal stretching and then transverse stretching. Specifically, a method that combines longitudinal stretching utilizing the speed difference between rolls and transverse stretching using a tenter is often used.

[0079] Alternatively, a film laminated with a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina, or a barrier film containing a gas barrier layer of polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, vinylidene chloride, etc. Use of such a film can provide a laminate with barrier properties against water vapor, oxygen, alcohol, inert gases, volatile organic compounds (fragrances), etc.

[0080] The film surface may be subjected to various surface treatments such as flame treatment and corona discharge treatment as necessary so that an adhesive layer without defects such as film breakage or repellency is formed.

[0081] Alternatively, the laminate of the present invention can be obtained by applying the adhesive of the present invention as an adhesion promoter (anchor coating agent) to a film using a laminator, carrying out a curing reaction, and then laminating a molten polymer material using an extruder (extrusion lamination method). The film may be the same as the film used in the dry lamination method and non-solvent lamination method described above. The polymer material to be melted is preferably a polyolefin resin such as low-density polyethylene resin, linear low-density polyethylene resin, or ethylene-vinyl acetate copolymer resin.

[0082] More specific examples of the laminate configuration include, but are not limited to, (1) base film 1 / adhesive layer 1 / sealant film (2) base film 1 / adhesive layer 1 / metal-deposited unstretched film (3) base film 1 / adhesive layer 1 / metal-deposited stretched film (4) transparent vapor-deposited stretched film / adhesive layer 1 / sealant film (5) base film 1 / adhesive layer 1 / base film 2 / adhesive layer 2 / sealant film (6) base film 1 / adhesive layer 1 / metal-deposited stretched film / adhesive layer 2 / sealant film (7) base film 1 / adhesive layer 1 / transparent vapor-deposited stretched film / adhesive layer 2 / sealant film (8) base film 1 / adhesive layer 1 / metal layer / adhesive layer 2 / sealant film (9) base film 1 / adhesive layer 1 / base film 2 / adhesive layer 2 / metal layer / adhesive layer 3 / sealant film (10) base film 1 / adhesive layer 1 / metal layer / adhesive layer 2 / base film 2 / adhesive layer 3 / sealant film.

[0083] Examples of the substrate film 1 used in structure (1) include OPP film, PET film, and nylon film. The substrate film 1 may also be coated to improve gas barrier properties or ink receptivity when a printing layer (described later) is provided. Examples of commercially available coated substrate films 1 include K-OPP film and K-PET film. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of sealant films include CPP film and LLDPE film. A printing layer may be provided on the surface of the substrate film 1 facing the adhesive layer 1 (or on the surface of the coating layer facing the adhesive layer 1 when a coated substrate film 1 is used). The printing layer is formed using various printing inks, such as gravure ink, flexographic ink, offset ink, stencil ink, and inkjet ink, using a common printing method conventionally used for printing on polymer films.

[0084] Examples of the base film 1 used in structures (2) and (3) include an OPP film and a PET film. The adhesive layer 1 is a cured coating of the adhesive of the present invention. As the metal-vapor-deposited unstretched film, a VM-CPP film obtained by vapor-depositing a metal such as aluminum onto a CPP film can be used, and as the metal-vapor-deposited stretched film, a VM-OPP film obtained by vapor-depositing a metal such as aluminum onto an OPP film can be used. As in structure (1), a printed layer may be provided on the surface of the base film 1 facing the adhesive layer 1.

[0085] Examples of the transparent vapor-deposited stretched film used in structure (4) include films obtained by vapor-depositing silica or alumina onto OPP film, PET film, nylon film, etc. A film having a coating applied to the vapor-deposited inorganic layer of silica or alumina may also be used for the purpose of protecting the vapor-deposited inorganic layer. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). A printed layer may be provided on the surface of the transparent vapor-deposited stretched film on the adhesive layer 1 side (when a film having a coating applied to the inorganic vapor-deposited layer is used, the surface of the coating layer on the adhesive layer 1 side). The method of forming the printed layer is the same as in structure (1).

[0086] Examples of the base film 1 used in structure (5) include a PET film, etc. Examples of the base film 2 include a nylon film, etc. At least one of the adhesive layer 1 and the adhesive layer 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on the surface of the base film 1 on the adhesive layer 1 side.

[0087] Examples of the base film 1 in structure (6) include those similar to those in structures (2) and (3). Examples of metal-vapor-deposited stretched films include VM-OPP films and VM-PET films, which are OPP films or PET films that have been subjected to metal vapor deposition of aluminum or the like. At least one of adhesive layer 1 and adhesive layer 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on the surface of base film 1 on the adhesive layer 1 side.

[0088] Examples of the base film 1 in structure (7) include a PET film. Examples of the transparent vapor-deposited stretched film include those similar to those in structure (4). At least one of the adhesive layers 1 and 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on the surface of the base film 1 on the adhesive layer 1 side.

[0089] Examples of the base film 1 in structure (8) include a PET film. Examples of the metal layer include aluminum foil. At least one of the adhesive layers 1 and 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on the surface of the base film 1 on the adhesive layer 1 side.

[0090] In structures (9) and (10), the base film 1 may be a PET film or the like. The base film 2 may be a nylon film or the like. The metal layer may be an aluminum foil or the like. At least one of the adhesive layers 1, 2, and 3 is a cured coating film of the adhesive of the present invention. The sealant film may be the same as that in structure (1). As in structure (1), a printed layer may be provided on the surface of the base film 1 on the adhesive layer 1 side.

[0091] When the laminate of the present invention includes at least one of a metal vapor deposition film, a transparent vapor deposition film, and a metal layer, the adhesive layer in contact with the metal vapor deposition layer, the transparent vapor deposition layer, and the metal layer is preferably a cured coating film of the adhesive of the present invention.

[0092] When the adhesive of the present invention is a solvent-based adhesive, the adhesive of the present invention is applied to a film material as a substrate using a roll such as a gravure roll, and the organic solvent is evaporated by heating in an oven or the like, and then the other substrate is laminated to obtain a laminate of the present invention. After lamination, it is preferable to perform an aging treatment. The aging temperature is preferably room temperature to 80°C, and the aging time is preferably 12 to 240 hours.

[0093] When the adhesive of the present invention is a solventless type, the adhesive of the present invention, which has been preheated to about 40°C to 100°C, is applied to a film material serving as a substrate using a roll such as a gravure roll, and then the other substrate is immediately laminated to obtain a laminate of the present invention. After lamination, it is preferable to perform an aging treatment. The aging temperature is preferably room temperature to 70°C, and the aging time is preferably 6 to 240 hours.

[0094] When the adhesive of the present invention is used as an adhesion promoter, the adhesion promoter of the present invention is applied to a film material as a substrate using a roll such as a gravure roll, the organic solvent is evaporated by heating in an oven or the like, and then a molten polymer material is laminated using an extruder to obtain the laminate of the present invention.

[0095] The amount of adhesive to be applied is adjusted as appropriate. For example, in the case of a solvent-based adhesive, the solid content is 1 g / m. ２ 10g / m or more ２ Preferably 1 g / m or less ２ 5g / m or more ２In the case of a solvent-free adhesive, the amount of adhesive applied is adjusted to, for example, 1 g / m ２ 10g / m or more ２ Preferably 1 g / m or less ２ 5g / m or more ２ The following is the result.

[0096] When the adhesive of the present invention is used as an adhesive auxiliary, the coating amount is, for example, 0.03 g / m ２ 0.09g / m or more ２ The solid content is as follows:

[0097] The laminate of the present invention may further include other films or substrates in addition to the above-described configurations (1) to (10). As the other substrates, in addition to the above-described stretched films, unstretched films, and transparent vapor-deposited films, porous substrates such as paper, wood, and leather can also be used. The adhesive used to bond the other substrates may or may not be the adhesive of the present invention.

[0098] 5. Packaging Materials The laminate of the present invention can be used as a multilayer packaging material for the purpose of protecting food, medicines, etc. When used as a multilayer packaging material, the layer structure can be changed depending on the contents, the environment of use, and the form of use.

[0099] The packaging material of the present invention can be obtained by using the laminate of the present invention, overlapping the sealant film surfaces of the laminates so that they face each other, and then heat-sealing the peripheral edges. Examples of bag-making methods include folding or overlapping the laminate of the present invention so that the inner layer surfaces (sealant film surfaces) face each other, and heat-sealing the peripheral edges using, for example, a side seal, two-sided seal, three-sided seal, four-sided seal, envelope seal, flared seal, flat-bottom seal, square-bottom seal, gusset seal, or other heat seal methods. The packaging material of the present invention can take various forms depending on the contents, usage environment, and usage form. Self-standing packaging materials (standing pouches) are also possible. Heat-sealing can be performed using known methods such as bar seal, rotary roll seal, belt seal, impulse seal, high-frequency seal, and ultrasonic seal.

[0100] The packaging material of the present invention is filled with contents through its opening, and the opening is then heat-sealed to produce a product using the packaging material of the present invention. The contents to be filled include confectioneries such as rice crackers, bean snacks, nuts, biscuits, cookies, wafer snacks, marshmallows, pies, semi-dried cakes, candies, and snacks; staple foods such as bread, snack noodles, instant noodles, dried noodles, pasta, aseptically packaged cooked rice, rice porridge, porridge, packaged rice cakes, and cereal foods; processed agricultural products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, nametake mushrooms, konjac, processed wild vegetables, jams, peanut cream, salads, frozen vegetables, and processed potatoes; processed livestock products such as ham, bacon, sausages, processed chicken products, and corned beef; and fish ham and sausages. Examples of suitable packaging materials include processed seafood products such as fish paste products, kamaboko (fish paste), nori (seaweed paste), tsukudani (simmered foods in soy sauce), dried bonito flakes, salted fish, smoked salmon, and spicy cod roe, fruit pulp such as peaches, mandarin oranges, pineapples, apples, pears, and cherries, vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes, prepared foods such as frozen and chilled prepared foods, including hamburger steaks, meatballs, fried seafood, gyoza (dumplings), and croquettes, dairy products such as butter, margarine, cheese, cream, instant creamy powder, and infant formula, liquid seasonings, retort curry, and pet food. The packaging material of the present invention can also be used as a packaging material for cigarettes, pharmaceuticals such as disposable body warmers and infusion packs, cosmetics, and vacuum insulation materials.

[0101] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, the blending compositions and other numerical values ​​are based on mass.

[0102] <Adhesive Preparation> [Polyol Composition] (Polyol Composition A1) 80.12 parts of ethylene glycol, 148.12 parts of phthalic anhydride, and 0.02 parts of titanium tetraisopropoxide were charged into a polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser, and the mixture was gradually heated so that the temperature at the top of the distillation tube did not exceed 100 ° C. The internal temperature was maintained at 220 ° C. The esterification reaction was terminated when the acid value reached 1 mg KOH / g or less, yielding a polyester polyol with a number average molecular weight of 900. The hydroxyl value was 124.7 mg KOH / g, and the glass transition temperature was 10 ° C. or less. 310.13 parts of ethyl acetate was added as a dilution solvent while heating to 60 ° C., and the mixture was stirred for 1 hour to obtain Polyol Composition A1.

[0103] (Polyol Composition A2) 100.12 parts of ethylene glycol, 148.12 parts of phthalic anhydride, and 0.02 parts of titanium tetraisopropoxide were charged into a polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser, and the internal temperature was maintained at 220°C by gradually heating so that the temperature at the top of the distillation tube did not exceed 100°C. The esterification reaction was terminated when the acid value reached 1 mgKOH / g or less, yielding a polyester polyol with a number average molecular weight of 400. The hydroxyl value was 280.5 mgKOH / g, and the glass transition temperature was 10°C or less. The resulting polyester polyol was used as polyol composition A2.

[0104] (Polyol Composition A3) 79.10 parts of ethylene glycol, 74.06 parts of phthalic anhydride, 73.07 parts of adipic acid, and 0.01 parts of titanium tetraisopropoxide were charged into a polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser, and the mixture was gradually heated so that the temperature at the top of the distillation tube did not exceed 100 ° C. The internal temperature was maintained at 220 ° C. The esterification reaction was terminated when the acid value reached 1 mg KOH / g or less, yielding a polyester polyol with a number average molecular weight of 800. The hydroxyl value was 143.2 mg KOH / g, and the glass transition temperature was 10 ° C. or less. The resulting polyester polyol was used as polyol composition A3.

[0105] (Polyol Composition A4) A polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser was charged with 91.05 parts of diethylene glycol, 34.65 parts of 2-methyl-1,3-propanediol, 143.67 parts of adipic acid, 15.79 parts of trimethylolpropane, and 0.01 parts of titanium tetraisopropoxide. The mixture was gradually heated so that the temperature at the top of the distillation tube did not exceed 100°C, and the internal temperature was maintained at 220°C. The esterification reaction was terminated when the acid value reached 1 mgKOH / g or less, yielding a polyester polyol having a number average molecular weight of 750. The hydroxyl value was 185.1 mgKOH / g, and the glass transition temperature was 10°C or less. The resulting polyester polyol was used as polyol composition A4.

[0106] [Polyisocyanate Composition] (Polyisocyanate Composition B1) A polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser was charged with 92.00 parts of ethylene glycol, 118.50 parts of phthalic anhydride, 29.23 parts of adipic acid, and 0.01 parts of titanium tetraisopropoxide, and the mixture was gradually heated so that the temperature at the top of the distillation tube did not exceed 100° C., and the internal temperature was maintained at 220° C. When the acid value reached 1 mgKOH / g or less, the esterification reaction was terminated, yielding a polyester intermediate B1′ having a number average molecular weight of 500.

[0107] A reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, a cooling condenser, and a dropping funnel was charged with 71.45 parts of xylylene diisocyanate and 46.26 parts of Millionate MN (a mixture of 4,4'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate), and the mixture was stirred while heating to 70°C. 92.28 parts of Polyester Intermediate B1' was added dropwise using the dropping funnel over 2 hours, and the mixture was further stirred for 4 hours to obtain Polyisocyanate Composition B1. The NCO% measured in accordance with JIS-K1603 was 15.1%.

[0108] (Polyisocyanate Composition B2) A polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser was charged with 79.27 parts of ethylene glycol, 59.25 parts of phthalic anhydride, 87.68 parts of adipic acid, and 0.02 parts of titanium tetraisopropoxide, and the mixture was gradually heated so that the temperature at the top of the distillation tube did not exceed 100° C., and the internal temperature was maintained at 220° C. When the acid value reached 1 mgKOH / g or less, the esterification reaction was terminated, yielding a polyester intermediate B2′ having a number average molecular weight of 850.

[0109] A reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, a cooling condenser, and a dropping funnel was charged with 69.06 parts of xylylene diisocyanate and 30.61 parts of Millionate MN (a mixture of 4,4'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate), and the mixture was stirred while heating to 70°C. 100.33 parts of Polyester Intermediate B2' was added dropwise using the dropping funnel over 2 hours, and the mixture was further stirred for 4 hours to obtain Polyisocyanate Composition B2. The NCO% measured in accordance with JIS-K1603 was 15.4%.

[0110] (Polyisocyanate Composition B3) A polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser was charged with 100.12 parts of ethylene glycol, 148.12 parts of phthalic anhydride, and 0.02 parts of titanium tetraisopropoxide, and the mixture was gradually heated so that the temperature at the top of the distillation tube did not exceed 100° C., and the internal temperature was maintained at 220° C. The esterification reaction was terminated when the acid value reached 1 mgKOH / g or less, yielding a polyester intermediate B3′ having a number average molecular weight of 400.

[0111] A reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, a cooling condenser, and a dropping funnel was charged with 75.55 parts of xylylene diisocyanate and 48.07 parts of Millionate MN (a mixture of 4,4'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate), and the mixture was stirred while heating to 70°C. 76.37 parts of Polyester Intermediate B3' was added dropwise using the dropping funnel over 2 hours, and the mixture was further stirred for 4 hours to obtain Polyisocyanate Composition B3. The NCO% measured in accordance with JIS-K1603 was 16.6%.

[0112] (Polyisocyanate Composition B4) A polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser was charged with 48.16 parts of ethylene glycol, 62.98 parts of 2-methyl-1,3-propanediol, and 129.69 parts of adipic acid, and the mixture was gradually heated so that the temperature at the top of the distillation tube did not exceed 100° C., and the internal temperature was maintained at 220° C. When the acid value reached 1 mgKOH / g or less, the esterification reaction was terminated, yielding a polyester intermediate B4′ having a number average molecular weight of 600.

[0113] A reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, a cooling condenser, and a dropping funnel was charged with 119.05 parts of Lupranate MI (a mixture of 4,4'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate) and stirred while heating to 70°C. 81.63 parts of Polyester Intermediate B4' was added dropwise using the dropping funnel over 2 hours, and the mixture was further stirred for 4 hours to obtain Polyisocyanate Composition B4. The NCO% measured in accordance with JIS-K1603 was 14.5%.

[0114] [Adhesives] (Examples 1) to (Examples 8) The prepared polyol compositions and polyisocyanate compositions were blended in the ratios shown in Tables 1 and 2 to obtain adhesives of Examples 1 to 8.

[0115] Comparative Examples 1 to 8 The prepared polyol compositions and polyisocyanate compositions were blended in the ratios shown in Tables 3 and 4 to obtain adhesives of Comparative Examples 1 to 8.

[0116] <Production of Laminate> (Example 1) The adhesive of Example 1 was applied to a laminate in a coating amount of 3.0 g / m using a bar coater. ２ The adhesive was applied to the printed surface of a 20 μm thick OPP film ("P2161" manufactured by Toyobo Co., Ltd.) so that the total solids content was 100%. The diluted solvent was evaporated and the film was dried using a dryer set at a temperature of 70° C. Next, the adhesive surface of the OPP film to which the adhesive had been applied was bonded to the vapor-deposited surface of a 25 μm thick aluminum-deposited CPP film ("2203" manufactured by Toray Advanced Film Co., Ltd.). Aging was carried out at 40° C. for 2 days, and the laminate of Example 1 was obtained.

[0117] Example 2, Comparative Example 1, Comparative Example 2 Laminates of Example 2 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the adhesive was changed.

[0118] (Example 3) The adhesive of Example 3 was heated to approximately 70°C and applied to the printed surface of a 20 µm thick OPP film ("P2161" manufactured by Toyobo Co., Ltd.) in a coating amount of 2.0 g / m using a solventless test coater. ２ (solid content), and then the vapor-deposited surface of a 25 μm-thick aluminum-deposited CPP film ("2203" manufactured by Toray Advanced Film Co., Ltd.) was bonded to the adhesive-coated surface. Aging was carried out at 40° C. for 2 days, and a laminate of Example 3 was obtained.

[0119] (Example 4) to (Example 8), (Comparative Example 3) to (Comparative Example 8) Laminates of Examples 4 to 8 and Comparative Examples 3 to 8 were obtained in the same manner as in Example 3 except that the adhesive was changed.

[0120] Example 9 The adhesive of Example 9 was heated to approximately 70°C and applied to the vapor-deposited surface of a 25 µm thick aluminum-deposited CPP film ("2203" manufactured by Toray Advanced Film Co., Ltd.) in a coating amount of 2.0 g / m using a solventless test coater. ２ (solid content), and then the printed surface of a 12 μm-thick PET film ("P5102" manufactured by Toyobo Co., Ltd.) and the adhesive-coated surface were bonded together. Aging was carried out at 40° C. for 2 days, and a laminate of Example 9 was obtained.

[0121] <Evaluation> (Oxygen permeability) The obtained laminate was cut into a size of 10 cm x 10 cm, and the oxygen permeability was measured in an atmosphere of 23°C and 0% RH using an OX-TRAN2 / 21 (oxygen permeability measuring device manufactured by Mocon Co., Ltd.) in accordance with JIS-K7126 (constant pressure method). RH represents humidity. The results are summarized in Table 1-4.

[0122] (Gelbo Flex Test (Bending Test)) The laminated film after aging was cut to a size of 30 cm x 20 cm, and a bending test was carried out using a Gelbo Flex tester (BE-1006 Gelbo Flex Tester with Thermostatic Chamber, Tester Sangyo Co., Ltd.) in accordance with ASTM F392. The bending test was carried out under the conditions of 440° / 90 mm, linear motion of 65 mm, 23°C, and 20 bending times, and the oxygen permeability after Gelbo Flex treatment was measured. The unit is cc / m. ２ The results are summarized in Table 1-4.

[0123]

[0124]

[0125]

[0126]

[0127] As is clear from the Examples and Comparative Examples, the laminates obtained using the adhesive of the present invention were excellent in gas barrier properties and flex resistance, whereas the laminates obtained using the adhesives of the Comparative Examples were unable to achieve both gas barrier properties and flex resistance at satisfactory levels.

Claims

1. Polyester polyisocyanate (B) comprising the product of the reaction between an isocyanate compound and a polyester polycondensate of polycarboxylic acid or its derivatives (IB) and at least one polyhydric alcohol (II-B), in which the polycarboxylic acid or its derivatives (IB) includes at least one aliphatic polycarboxylic acid containing eight or fewer non-carboxyl carbon atoms or its derivatives (IBi) and at least one aromatic polycarboxylic acid or its derivatives (IB-ii); and 1. Polyhydric alcohol (II-B) including aliphatic polyhydric alcohols containing eight or fewer carbon atoms (II-Bi).

2. Polyester polyisocyanates (B) according to Reputation 1, where the molar ratio between aliphatic polycarboxylic acid containing eight or fewer non-carboxyl carbon atoms or its derivatives (IIBi) and aromatic carboxylic acid or its derivatives (IIB-II) is between 1:9 and 9:

1.

3. Polyester polyisocyanates (B) according to either Reputation 1 or 2,where: at least one aliphatic polycarboxylic acid containing eight or fewer non-carboxyl carbon atoms or derivatives (lBi) is selected from a group comprising oxalic acid, malonic acid, ethylmalonic acid, dimethylmanolic acid, succinic acid, dimethylsuccinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, cebasic acid, 1,3-cyclopentane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, 4-cyclohexane dicarboxylic acid, and 3-methyl-4-cyclohexene 1,2-dicarboxylic acid and anhydride and methyl ether of that substance; and At least one aromatic polycarboxylic acid or derivative (IB-ii) was selected from a group comprising orthophthalic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromelitic acid, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, naphthalic acid, biphenyl dicarboxylic acid, and 1,2-bis(phenoxy)ethane-p.p'-dicarboxylic acid and anhydride and methyl ether of these compounds; 4. Polyirocyanate compositions which are used in adhesives consisting of polyol and polyirocyanate compositions, polyisocyanate compositions combined with polyester polyisocyanate(B) according to one of the claims 1 to 3; 5. Polyisocyanate compositions according to claim 4, which are additionally combined with viscosity modifiers; 6. Adhesives consisting of polyol and polyisocyanate compositions according to one of the claims 4 or 5; 7. Adhesives according to claim 6, where the polyol composition consists of at least one polyol selected from a group consisting of a polyether core, a polyurethane core, and a polyether core; 8. Adhesives according to claim 6,Where: The polyol composition consists of a polyol with a polyester core (A) that is a polycondensate of polycarboxylic acid or its derivatives (IA) and at least one polyhydric alcohol (II-A); the polycarboxylic acid or its derivatives (IA) including aliphatic polycarboxylic acid containing eight or fewer non-carboxyl carbon atoms or its derivatives (IAi) and aromatic polycarboxylic acid or its derivatives (IA-ii); and the polyhydric alcohol (II-A) including aliphatic polyhydric alcohol containing eight or fewer carbon atoms (II-Ai).

9. The binder following claim 8, where the molar ratio of the mixture of aliphatic polycarboxylic acid containing eight or fewer non-carboxyl carbon atoms or its derivatives (IAi) and aromatic polycarboxylic acid or its derivatives (IA-ii) is between 1:9 and 9:

1.

10. Any of the binding agents in claims 7 through 9, in which the polyol has an average molecular weight of 300 or greater and 3000 or less.

11. A product that is a layer consisting of the first substrate.The second substrate, and the adhesive layer connecting the first and second substrates, where the adhesive layer is a fixed coating of the adhesive as specified in claims 6 through 10.

12. Packaging material incorporating the layered product as specified in claim 11;