WO2023112688A1 - Adhesive, laminate, and packaging material - Google Patents

Abstract

Provided is a two-part curable adhesive that has excellent heat resistance and deformation moderating ability.　The two-part curable adhesive contains a polyisocyanate composition (X) and a polyol composition (Y). The polyisocyanate composition (X) includes a bifunctional polyisocyanate compound (A1) and a polyisocyanate compound (A2) having a functionality of three or more. The polyol composition (Y) includes a polyester polyol (B). The blended amount of the polyisocyanate compound (A1) with respect to the total amount of the polyisocyanate compound (A1) and the polyisocyanate compound (A2) is 5-50 mass%.

Description

Adhesives, laminates, packaging materials

The present invention relates to an adhesive, a laminate obtained using the adhesive, and a packaging material.

As packaging materials for foods, medical products, cosmetics, daily necessities, etc., multi-layer laminates of metal foils such as aluminum foil or metallized films and plastic films such as polyethylene, polypropylene, vinyl chloride, polyester, and nylon are used. It is These laminates are obtained by appropriately combining various types of plastic films, metal vapor-deposited films, or metal foils according to the properties required for each application, and bonding them together with an adhesive. As the adhesive, a two-liquid curable adhesive composed of a polyol composition and a polyisocyanate composition is generally used (for example, Patent Document 1).

JP 2014-101422 A

The level of demand for these properties for adhesives is increasing day by day. For example, in the field of food packaging, there is a growing movement to improve food sterilization efficiency in line with the trend of improving eating habits, and there is an opportunity to replace the conventional hot water storage type retort processing with hot water spray type retort processing. is increasing. In the hot water spray type retort treatment, high-temperature and high-pressure hot water spray may directly hit the laminate, so the adhesive is required to have a higher level of retort resistance than conventional ones.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a laminating adhesive having excellent retort resistance (heat resistance and deformation relaxation property).

The present invention comprises a polyisocyanate composition (X) and a polyol composition (Y), wherein the polyisocyanate composition (X) is a bifunctional polyisocyanate compound (A1) and a trifunctional or higher polyisocyanate compound ( A2), the polyol composition (Y) contains the polyester polyol (B), and the amount of the polyisocyanate compound (A1) in the total amount of the polyisocyanate compound (A1) and the polyisocyanate compound (A2) is 5 to It relates to a two-component curing adhesive that is 50% by mass.

According to the adhesive of the present invention, it is possible to provide adhesives, laminates, and packaging materials with excellent retort resistance.

<Adhesive>
The adhesive of the present invention comprises a polyisocyanate composition (X) and a polyol composition (Y), wherein the polyisocyanate composition (X) is a difunctional polyisocyanate compound (A1) and a trifunctional or higher poly and the isocyanate compound (A2), the polyol composition (Y) contains the polyester polyol (B), and the amount of the polyisocyanate compound (A1) in the total amount of the polyisocyanate compound (A1) and the polyisocyanate compound (A2) is a two-component curing adhesive with a content of 5 to 50% by mass. The adhesive of the present invention will be described in detail below.

(Polyisocyanate composition (X))
The polyisocyanate composition (X) contains a bifunctional polyisocyanate compound (A1) and a trifunctional or higher polyisocyanate compound (A2). Known polyisocyanate compounds can be used without any particular limitation.

Examples of the bifunctional polyisocyanate compound (A1) include butane-1,4-diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, Aliphatic diisocyanates such as xylylene diisocyanate, m-tetramethylxylylene diisocyanate, lysine diisocyanate;

Cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, norbornane diisocyanate, etc. cycloaliphatic diisocyanate of;

1,5-naphthylene 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, aromatic diisocyanate such as tolylene diisocyanate,

Examples include adducts which are reaction products of these diisocyanates and low-molecular-weight diols, allophanates and uretdiones of these diisocyanates, and modified products obtained by modifying some of the isocyanate groups of these polyisocyanates with carbodiimide.

Examples of the tri- or more functional polyisocyanate compound (A2) include adducts which are reaction products of the above diisocyanate and tri- or more functional polyols, allophanate forms, biuret forms, nurate forms, and oligomers (e.g., polymeric MDI) of the above diisocyanates. etc. The average number of functional groups of the polyisocyanate compound (A2) is preferably 5 or less, more preferably 4 or less.

Trimethylolethane, trimethylolpropane, glycerin, hexanetriol, pentaerythritol and the like are examples of tri- or higher functional polyols used for synthesis of adducts, but are not limited thereto. Moreover, you may use individually by 1 type, and may use 2 or more types together.

In addition, in the present invention, the amount of the polyisocyanate compound (A1) in the total amount of the polyisocyanate compound (A1) and the polyisocyanate compound (A2) is 5 to 50% by mass. As a result, the adhesive can be excellent in retort resistance (heat resistance, deformation relaxation property). The content of the polyisocyanate compound (A1) is more preferably 10% by mass or more, more preferably 15% by mass or more. Moreover, it is more preferably 40% by mass or less, and more preferably 30% by mass or less.

The reason why the adhesive of the present invention is excellent in retort resistance is presumed as follows. When a laminate obtained by laminating a plurality of substrates using a laminating adhesive is subjected to a retort treatment, separation is likely to occur at the interface between the adhesive and the laminate. This is presumably because the adhesive layer cannot mitigate the deformation of the base material due to retorting. On the other hand, if the adhesive layer is too soft, the heat applied during the retort treatment will reduce the adhesive strength, resulting in peeling of the laminate. Therefore, a bifunctional polyisocyanate compound (A1) and a trifunctional or higher polyisocyanate compound (A2) are used in combination as a polyisocyanate composition, and the compounding ratio is within the above range, so that the adhesive layer can be formed by retort treatment. We have completed an adhesive that can alleviate the deformation of the base material, imparts moderate flexibility to the extent that the adhesive strength does not decrease, and has excellent retort resistance (heat resistance, deformation relaxation property).

Furthermore, at least one of the polyisocyanate compounds (A1) and (A2) preferably contains an aliphatic polyisocyanate, and hexamethylene diisocyanate and its derivatives (adduct, allophanate, nurate, biuret, carbodiimide modified) preferably included. As a result, the flexibility of the coating film can be further increased, and the adhesive can be excellent in deformation relaxation.

Also, at least one of the polyisocyanate compounds (A1) and (A2) preferably contains an aromatic polyisocyanate. As a result, the adhesive can have excellent normal state adhesive strength and heat resistance.

(Polyol composition (Y))
The polyol composition (Y) used in the adhesive of the invention contains a polyester polyol (B1). Polyester polyol (B1) is a reaction product of a monomer composition containing polyhydric carboxylic acid and polyhydric alcohol.

Polyvalent carboxylic acids used in the synthesis of the polyester polyol (B1) include malonic acid, ethylmalonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, succinic anhydride, alkenylsuccinic anhydride, and glutaric acid. , adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, dimer acid, trimer acid, tetramer acid and other aliphatic polycarboxylic acids;

Aliphatic polycarboxylic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimelate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate alkyl esters of acids;

1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid , tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, hymic anhydride, hetic anhydride, etc. group polycarboxylic acid;

orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic anhydride, naphthalic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic acid di aromatic polycarboxylic acids such as anhydrides, 5-sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride;

and methyl esters of aromatic polyvalent carboxylic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylate;

The polyhydric alcohol used for synthesizing the polyester polyol (B1) may be a diol or a trifunctional or higher polyol. Examples of the diol include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1, 2,2-trimethyl-1,3-propanediol, 2,2-dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1, 3-butanediol, 1,5-pentanediol, 3-methyl 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohexane, 2,2,4- Aliphatic diols such as trimethyl-1,3-pentanediol and dimer diol;

Ether glycols such as polyoxyethylene glycol and polyoxypropylene glycol;

Modification obtained by ring-opening polymerization of the aliphatic diol with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether polyether diol;

A lactone-based polyester polyol obtained by a polycondensation reaction between the aliphatic diol and various lactones such as lactanoids and ε-caprolactone;

Bisphenols such as bisphenol A and bisphenol F;

Examples include alkylene oxide adducts of bisphenols obtained by adding ethylene oxide, propylene oxide, etc. to bisphenols such as bisphenol A and bisphenol F.

The tri- or more functional polyols are aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol;

Modification obtained by ring-opening polymerization of the aliphatic polyol with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether polyether polyols;

Examples include lactone-based polyester polyols obtained by a polycondensation reaction between the above-mentioned aliphatic polyol and various lactones such as ε-caprolactone.

The polyester polyol (B1) is a polyester polyurethane polyol obtained by chain-extending a polyester polyol which is a reaction product of a polyhydric carboxylic acid and a polyhydric alcohol with a polyisocyanate compound, or a polyhydric alcohol, a polyhydric carboxylic acid and a polyisocyanate compound. Also preferred is a polyester polyurethane polyol that is the reaction product of a composition comprising: As the polyisocyanate compound used for synthesizing the polyester polyurethane polyol, the same compounds as exemplified as the polyisocyanate compounds (A1) and (A2) can be used.

The polyester polyol (B1) used in the present invention preferably contains a tetramer acid as the polyvalent carboxylic acid. As a result, the adhesive can be made more excellent in retort resistance (heat resistance and hot water resistance). Tetramer acid is a product of the Diels-Alder reaction of unsaturated fatty acids such as oleic acid and linoleic acid. and tetrafunctional carboxylic acids obtained by reacting unsaturated fatty acids contained in recovered oils including natural oils of these fatty acids. It may be acyclic, monocyclic, polycyclic, or aromatic, or may be a combination of any two or more.

The carboxyl group of the tetramer acid is directly bonded to the saturated alkyl group, and the distance from the branch point to the reaction point (carboxyl group) is long, so it is less susceptible to steric hindrance. Combined with the fact that it becomes liquid at a relatively low temperature, the carboxyl group of the tetramer acid is highly reactive and is preferentially consumed at the beginning of the esterification reaction. Therefore, the polyester polyol (B1) using a tetramer acid as a starting material contains the polyester polyol (b1) having a star-shaped branched structure centered on the tetramer acid. The branch points derived from the polyester polyol (b1) are less likely to undergo decomposition reactions even in a high-temperature environment or in the presence of moisture. Therefore, the branched structure can be maintained even in a high-temperature environment, and a decrease in adhesive strength can be suppressed. That is, the adhesive can be excellent in heat resistance and hot water resistance.

Furthermore, since there is a distance from the branch point of the tetramer acid to the reaction point as described above, polyester polyol (b1) does not have localized ester bonds near the branch point derived from the tetramer acid. For this reason, flexibility can be maintained even if the branching point concentration of the cured coating film is high, and it can be used not only for adhesion between films, but also for relatively hard layers such as aluminum foil, aluminum vapor deposition layers, and inorganic oxide vapor deposition layers. , the adhesion to a relatively soft layer such as a resin film is also excellent. The adhesive layer can also be expected to act as a buffer to prevent cracking and peeling of the deposited aluminum layer and deposited inorganic oxide layer. Even when water penetrates into the effect coating film, the molecular chains are not cut at once near the branch point, so the adhesive can have good hot water resistance.

When the polycarboxylic acid used for synthesizing the polyester polyol (B1) contains a tetramer acid, the amount thereof is not particularly limited. When it is 0.1% by mass or more, the heat resistance tends to be improved, which is preferable. There is no particular upper limit, but if it is too large, gelation tends to occur during the production of the polyester polyol (B1), making production more difficult. More preferably, it is 0.1% by mass or more and 2.0% by mass or less. When the polyester polyol (B1) is a polyester polyurethane polyol, the monomer composition contains polyhydric carboxylic acid, polyhydric alcohol, and polyisocyanate compound used for its synthesis.

The polyester polyol (B1) used in the present invention preferably contains an aromatic polycarboxylic acid as the polycarboxylic acid. Thereby, it can be set as the adhesive agent excellent in heat resistance. When the polyhydric carboxylic acid contains an aromatic polyhydric carboxylic acid, the blending amount thereof can be appropriately adjusted, but is, for example, 5% by mass or more, 30% by mass or more, or 50% by mass or more. The upper limit is also adjusted appropriately, and as an example, it is 95% by mass or less, and 90% by mass or less.

Although the number average molecular weight (Mn) of the polyester polyol (B1) is not particularly limited, it is, for example, 500 to 100,000, more preferably 1,000 to 50,000. The weight average molecular weight (Mw) is, for example, 1,000 to 300,000, more preferably 2,000 to 200,000. In this specification, the number average molecular weight (Mn) and weight average molecular weight (Mw) are values measured by gel permeation chromatography (GPC) under certain conditions.

Measuring device; HLC-8320GPC manufactured by Tosoh Corporation
Column; TSKgel 4000HXL, TSKgel 3000HXL, TSKgel 2000HXL, TSKgel 1000HXL manufactured by Tosoh Corporation
Detector; RI (differential refractometer)
Data processing; Multi-station GPC-8020modelII manufactured by Tosoh Corporation
Measurement conditions; Column temperature 40°C
Solvent Tetrahydrofuran Flow rate 0.35 ml/min Standard; Monodisperse polystyrene Sample; 0.2 mass% tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

The hydroxyl value of the polyester polyol (B1) is preferably in the range of 1 to 150 mgKOH/g, more preferably 3 mgKOH/g or more and 100 mgKOH/g or less. Although the acid value of the polyester polyol (B) is not particularly limited, it is preferably 10.0 mgKOH/g or less. Although there is no particular lower limit, an example is 0.5 mgKOH/g or more. It may be 0 mg KOH/g. A hydroxyl value and an acid value can be measured by the method described in JIS-K0070.

The polyol composition (Y) may contain a polyol (B2) other than the polyester polyol (B1). Examples of the polyol (B2) include those exemplified as polyhydric alcohols used for preparing the polyester polyol (B1). When the polyol composition (Y) contains the polyol (B2), the blending amount of the polyester polyol (B1) is 70 parts by mass or more with respect to the total 100 parts by mass of the blending amount of the polyester polyol (B1) and the polyol (B2). It is preferably 80 parts by mass or more, more preferably 90 parts by mass or more.

(Other components of adhesive)
The adhesive of the present invention may contain components other than those mentioned above. These components may be contained in either or both of the polyisocyanate composition (X) and the polyol composition (Y), or they may be prepared separately from the polyisocyanate composition (X) and the polyol composition (Y) immediately before coating the adhesive. It may be used by mixing with the composition (X) and the polyol composition (Y). Each component will be described below.

(Organic solvent)
The adhesive of the present invention may be either solvent-based or non-solvent-based. The "solvent type" adhesive referred to in the present invention is a method of applying the adhesive to a base material, heating it in an oven or the like to volatilize the organic solvent in the coating film, and then bonding it to another base material. , refers to a form used in a so-called dry lamination method. Either one or both of the polyisocyanate composition (X) and the polyol composition (Y) can dissolve (dilute) the polyisocyanate composition (X) and the polyol composition (Y) used in the present invention. Contains organic solvents.

Examples of organic solvents 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. , methylene chloride, halogenated hydrocarbons such as ethylene chloride, dimethylsulfoxide, dimethylsulfamide and the like. The organic solvent used as a reaction medium during the production of the constituents of the polyisocyanate composition (X) or the polyol composition (Y) may also be used as a diluent during coating.

As used herein, the term "solvent-free" adhesive means that the polyisocyanate composition (X) and the polyol composition (Y) are substantially The form of the adhesive used in the so-called non-solvent lamination method, which is a method in which the adhesive is applied to the base material and then laminated to another base material without the process of heating in an oven or the like to volatilize the solvent. point to The constituent components of the polyisocyanate composition (X) or the polyol composition (Y) and the organic solvent used as the reaction medium during the production of the raw materials cannot be completely removed, resulting in the polyisocyanate composition (X) or the polyol composition ( If a small amount of organic solvent remains in Y), it is understood that the organic solvent is not substantially contained. Further, when the polyol composition (Y) contains a low-molecular-weight alcohol, the low-molecular-weight alcohol reacts with the polyisocyanate composition (X) and becomes part of the coating film, so it is not necessary to volatilize after coating. Such forms are therefore also treated as solventless adhesives and low molecular weight alcohols are not considered organic solvents.

From the viewpoint of retort resistance, it is preferable that the polyester polyol (B) has a large number average molecular weight. Preferably, the adhesives of the present invention are solvent-based, as they can be easily adjusted.

(Combination amount)
From the viewpoint of deformation relaxation, the polyisocyanate composition (X) and the polyol composition (Y) are divided into isocyanate groups contained in the polyisocyanate composition (X) and polyol compositions (Y). It is preferable to adjust the molar ratio ([NCO]/[OH]) with the hydroxyl group to be 1.0 to 4.0.

(catalyst)
The adhesive of the present invention can accelerate the curing reaction by using a catalyst as necessary. The catalyst is not particularly limited as long as it promotes the urethanization reaction between the polyisocyanate composition (X) and the polyol composition (Y), and includes metal-based catalysts, amine-based catalysts, aliphatic cyclic amide compounds, titanium Chelate complexes and the like are exemplified.

Metal-based catalysts include metal complex-based, inorganic metal-based, and organic metal-based catalysts. As the metal complex catalyst, a group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), Co (cobalt) Examples include acetylacetonate salts of metals selected from the above, such as iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, zirconia acetylacetonate and the like. From the point of view of toxicity and catalytic activity, iron acetylacetonate (Fe(acac) ₃ ) or manganese acetylacetonate (Mn(acac) ₂ ) are preferred.

Examples of inorganic metal-based catalysts include those selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, and the like.

Organometallic catalysts include organozinc compounds such as zinc octylate, zinc neodecanoate, and zinc naphthenate; , dioctyltin dilaurate, dibutyltin oxide, dibutyltin dichloride and other organic tin compounds, nickel octylate, nickel naphthenate and other organic nickel compounds, cobalt octylate, cobalt naphthenate and other organic cobalt compounds, bismuth octylate, neodecanoic acid Examples include organic bismuth compounds such as bismuth and bismuth naphthenate, and titanium compounds such as tetraisopropyloxytitanate, dibutyltitanium dichloride, tetrabutyltitanate and butoxytitanium trichloride.

Amine catalysts include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, 2-methylquinuclidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyl Propylenediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N,N,N',N'',N''-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N', N″,N″-pentamethyldipropylenetriamine, N,N,N′,N′-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl)ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol , N,N-dimethyl-N'-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N'-(2-hydroxyethyl)propanediamine, bis(dimethylaminopropyl)amine, bis(dimethylaminopropyl) isopropanolamine, 3-quinuclidinol, N,N,N',N'-tetramethylguanidine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 1,8-diazabicyclo[5 .4.0]undecene-7, N-methyl-N′-(2-dimethylaminoethyl)piperazine, N,N′-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, 1-methyl imidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole, N,N-dimethylhexanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 1- (2-hydroxyethyl)imidazole, 1-(2-hydroxypropyl)imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, 1-(2-hydroxypropyl)-2-methylimidazole and the like.

Aliphatic cyclic amide compounds include, for example, δ-valerolactam, ε-caprolactam, ω-enanthollactam, η-capryllactam, β-propiolactam and the like. Among these, ε-caprolactam is more effective in accelerating hardening.

The titanium chelate complex is a compound whose catalytic activity is enhanced by ultraviolet irradiation, and a titanium chelate complex having an aliphatic or aromatic diketone as a ligand is preferable from the viewpoint of excellent curing acceleration effect. Further, in the present invention, in addition to aromatic or aliphatic diketones, those having alcohols having 2 to 10 carbon atoms as ligands are preferred from the viewpoint that the effects of the present invention are more pronounced.

These catalysts can be used alone or in combination of two or more. The amount of the catalyst compounded is preferably 0.001 to 3 parts by mass, more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the total solid content of the polyisocyanate composition (X) and the polyol composition (Y). is more preferable.

(pigment)
The adhesive of the present invention may contain a pigment if necessary. The pigments used are not particularly limited, and extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, and blue pigments described in the 1970 edition of the Handbook of Paint Materials (edited by the Japan Paint Manufacturers Association). Organic and inorganic pigments such as pigments, metal powder pigments, luminescent pigments, and pearlescent pigments, and plastic pigments can be used.

Extender pigments include, for example, precipitated barium sulfate, rice flour, precipitated calcium carbonate, calcium bicarbonate, Kansui stone, alumina white, silica, hydrous fine silica (white carbon), ultrafine anhydrous silica (Aerosil), silica sand (silica sand), talc, precipitated magnesium carbonate, bentonite, clay, kaolin, loess, and the like.

Specific examples of organic pigments include various insoluble azo pigments such as Benzidine Yellow, Hansa Yellow and Laked 4R; soluble azo pigments such as Laked C, Carmine 6B and Bordeaux 10; various (copper) pigments such as phthalocyanine blue and phthalocyanine green. Phthalocyanine pigments; various chlorine dyeing lakes such as rhodamine lake and methyl violet lake; various mordant pigments such as quinoline lake and fast sky blue; various pigments such as anthraquinone pigments, thioindigo pigments and perinone pigments vat dye-based pigments; various quinacridone-based pigments such as Cincasia Red B; various dioxazine-based pigments such as dioxazine violet; various condensed azo pigments such as chromophtal;

Examples of inorganic pigments include various chromates such as yellow lead, zinc chromate, molybdate orange; various ferrocyanic compounds such as Prussian blue; Various metal oxides such as zirconium oxide; various sulfides and selenides such as cadmium yellow, cadmium red, and mercury sulfide; various sulfates such as barium sulfate and lead sulfate; various types of silicon such as calcium silicate and ultramarine blue. acid salts; various carbonates such as calcium carbonate and magnesium carbonate; various phosphates such as cobalt violet and manganese purple; various metal powder pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder and brass powder; These metal flake pigments and mica flake pigments; metallic pigments and pearl pigments such as mica-like iron oxide pigments and mica-like iron oxide pigments coated with metal oxides; graphite, carbon black and the like.

Examples of plastic pigments include "Grandol PP-1000" and "PP-2000S" manufactured by DIC Corporation.

The pigment to be used may be appropriately selected according to the purpose. For example, inorganic oxides such as titanium oxide and zinc oxide are preferably used as white pigments because they are excellent in durability, weather resistance, and design. Carbon black is preferably used as the pigment.

The amount of the pigment compounded is, for example, 1 to 400 parts by mass with respect to 100 parts by mass of the total solid content of the polyisocyanate composition (X) and the polyol composition (Y). 10 to 300 parts by mass is more preferable.

(adhesion promoter)
The adhesive of the present invention may contain an adhesion promoter. Examples of adhesion promoters include coupling agents such as silane coupling agents, titanate coupling agents and aluminum coupling agents, and epoxy resins.

Silane coupling agents include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-γ-amino Aminosilanes such as propyltrimethyldimethoxysilane and N-phenyl-γ-aminopropyltrimethoxysilane; β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxy epoxysilanes such as propyltriethoxysilane; vinylsilanes such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane; hexamethyldisilazane, γ-mercaptopropyltrisilane; Methoxysilane and the like can be mentioned.

Titanate-based coupling agents include, for example, tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, tetrastearoxy Titanium etc. are mentioned.

Examples of aluminum-based coupling agents include acetoalkoxyaluminum diisopropylate.

As the epoxy resin, generally commercially available epibis type, novolak type, β-methyl epichloro type, cyclic oxirane type, glycidyl ether type, glycidyl ester type, polyglycol ether type, glycol ether type, epoxidized fatty acid ester type, poly Various epoxy resins such as carboxylic acid ester type, aminoglycidyl type, resorcinol type, triglycidyl tris(2-hydroxyethyl) isocyanurate, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, acryl glycidyl compounds such as ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol glycidyl ether, pt-butylphenyl glycidyl ether, diglycidyl adipate, o-diglycidyl phthalate, glycidyl methacrylate, butyl glycidyl ether; mentioned.

(Other additives)
In addition to the components described above, the adhesive of the present invention includes a leveling agent, inorganic fine particles such as colloidal silica and alumina sol, polymethyl methacrylate organic fine particles, an antifoaming agent, an anti-sagging agent, a wetting and dispersing agent, and a viscosity modifier. , UV absorber, metal deactivator, peroxide decomposer, flame retardant, reinforcing agent, plasticizer, lubricant, rust inhibitor, fluorescent whitening agent, inorganic heat ray absorber, flame retardant, electrification Inhibitors, dehydrating agents, known and commonly used thermoplastic elastomers, tackifiers, phosphoric compounds, melamine resins, reactive elastomers and the like may also be included. The blending amount of these additives is appropriately adjusted within a range that does not impair the desired properties of the adhesive of the present invention.

<Laminate>
The laminate of the present invention is obtained by laminating a plurality of films or papers using the adhesive of the present invention by a dry lamination method or a non-solvent lamination method. The film to be used is not particularly limited, and a suitable film can be selected according to the application. For example, for food packaging, polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low density polyethylene film, HDPE: high density polyethylene film, MDOPE: uniaxially oriented polyethylene film, OPE : Biaxially stretched polyethylene film), polypropylene film (CPP: non-stretched polypropylene film, OPP: biaxially stretched polypropylene film), ethylene vinyl alcohol copolymer, polyvinyl alcohol, or other gas-barrier resins with olefin on one or both sides Polyolefin films such as gas-barrier heat-sealable films provided with a heat-sealable resin layer, polyvinyl alcohol films, ethylene-vinyl alcohol copolymer films, and the like.

It is also preferable to use a biomass film formed of a material containing biomass-derived components. Biomass films are sold by various companies, and for example, sheets listed in the list of certified biomass products described by the Japan Organic Resources Association can be used.

Specific well-known biomass films include those made from biomass-derived ethylene glycol. Biomass-derived ethylene glycol is produced from biomass-derived ethanol (biomass ethanol). For example, biomass-derived ethylene glycol can be obtained by a method in which biomass ethanol is converted into ethylene glycol via ethylene oxide by a conventionally known method. Alternatively, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol can be preferably used.

For example, as an alternative to conventional polyethylene terephthalate films using petroleum-based raw materials, films containing biomass polyester, biomass polyethylene terephthalate, etc., having biomass-derived ethylene glycol as a diol unit and fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit. It has been known.

The dicarboxylic acid unit of biomass polyester uses the dicarboxylic acid derived from a fossil fuel. As dicarboxylic acids, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof can be used without limitation.
In addition to the above diol component and dicarboxylic acid component, a difunctional oxycarboxylic acid, a trifunctional or higher polyhydric alcohol for forming a crosslinked structure, a trifunctional or higher polycarboxylic acid and/or its anhydride. It may also be a copolymerized polyester in which a copolymerization component is added as a third component such as at least one polyfunctional compound selected from the group consisting of polycarboxylic acids and tri- or more functional oxycarboxylic acids.

In addition, for example, as an alternative to conventional polyolefin films using petroleum-based raw materials, biomass polyolefin films such as biomass polyethylene films containing polyethylene resins made from biomass-derived ethylene glycol, biomass polyethylene-polypropylene films, etc. Films are also known.
The polyethylene-based resin is not particularly limited except that the biomass-derived ethylene glycol is used as a part of the raw material. ethylene-α-olefin copolymer containing 90% by mass or more of units), etc., and these can be used alone or in combination of two or more.

The α-olefin constituting the copolymer of ethylene and α-olefin is not particularly limited, and may be 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, or the like having 4 to 10 carbon atoms. 8 α-olefins. Known polyethylene resins such as low density polyethylene resins, medium density polyethylene resins and linear low density polyethylene resins can be used. Among them, linear low-density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or ethylene and 1 - octene) are preferred, and linear low density polyethylene resins with densities between 0.910 and 0.925 g/cm ³ are more preferred.

As biomass films, those using biomass raw materials classified by the degree of biomass plastic specified by ISO16620 or ASTM D6866 are also distributed. Radiocarbon 14C exists in the atmosphere at a rate of 1 in 1012, and this rate does not change even with carbon dioxide in the atmosphere. Therefore, the carbon of the plant-derived resin contains radioactive carbon 14C. In contrast, the carbon of the fossil fuel-derived resin contains almost no radioactive carbon 14C. Therefore, by measuring the concentration of radioactive carbon 14C in the resin with an accelerator mass spectrometer, the content ratio of the plant-derived resin in the resin, that is, the degree of biomass plasticity can be obtained.

Examples of plant-derived low-density polyethylene, which is a biomass plastic having a biomass plastic degree of 80% or more, preferably 90% or more, as defined by ISO 16620 or ASTM D6866 include, for example, Braskem's product names "SBC818" and "SPB608". "SBF0323HC", "STN7006", "SEB853", "SPB681" and the like can be mentioned, and films using these as raw materials can be preferably used.

Films and sheets containing starch, which is a biomass raw material, and polylactic acid are also known. These can be appropriately selected and used depending on the application.

The biomass film may be a laminate obtained by laminating a plurality of biomass films, or may be a laminate of a conventional petroleum-based film and a biomass film. Moreover, these biomass films may be either unstretched films or stretched films, and the manufacturing method thereof is not limited.

The film may be stretched. As a stretching treatment method, it is common to melt-extrude a resin into a sheet by an extrusion film-forming method or the like, and then subject the sheet to simultaneous biaxial stretching or sequential biaxial stretching. In the case of sequential biaxial stretching, it is common to first perform longitudinal stretching and then laterally stretching. Specifically, a method of combining longitudinal stretching using a speed difference between rolls and lateral stretching using a tenter is often used.

Various surface treatments such as flame treatment and corona discharge treatment may be applied to the film surface as necessary so that an adhesive layer without defects such as film breakage and repellency is formed.

Alternatively, a barrier film containing a vapor-deposited layer of a metal such as aluminum, a metal oxide such as silica or alumina, or a gas barrier layer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride may be used in combination. good too. By using such a film, a laminate having barrier properties against water vapor, oxygen, alcohol, inert gas, volatile organic matter (fragrance) and the like can be obtained.

As the paper, a known paper base material can be used without any particular limitation. Specifically, it is produced by a known paper machine using natural fibers for papermaking such as wood pulp, but the papermaking conditions are not particularly specified. Examples of natural fibers for papermaking include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as Manila hemp pulp, sisal pulp and flax pulp, and pulp obtained by chemically modifying these pulps. The types of pulp that can be used include chemical pulp, ground pulp, chemi-grand pulp, thermomechanical pulp, and the like prepared by sulfate cooking, acidic/neutral/alkaline sulfite cooking, soda salt cooking, and the like.

Moreover, various types of commercially available fine paper, coated paper, lined paper, impregnated paper, cardboard, paperboard, etc. can also be used. A printed layer may be provided on the outer surface or the inner surface of the paper layer, if necessary.

As a more specific structure of the laminate,
(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 vapor deposited stretched film /adhesive layer 2/sealant film (7) base film 1/adhesive layer 1/transparent 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/ Examples include base film 2/adhesive layer 3/sealant film, but are not limited thereto.

Examples of the base material 1 used in configuration (1) include MDOPE film, OPE film, OPP film, PET film, nylon film, paper, and the like. Further, as the base material 1, a material coated for the purpose of improving gas barrier properties and ink receptivity when providing a printing layer, which will be described later, may be used. Commercially available products of the coated base film 1 include K-OPP film and K-PET film. The adhesive layer 1 is a cured coating film of the adhesive of the present invention. Sealant films include CPP films, LLDPE films, gas barrier heat seal films, and the like. On the surface of the substrate 1 on the side of the adhesive layer 1 (the surface of the coating layer on the side of the adhesive layer 1 when a coated substrate film 1 is used) or the surface opposite to the adhesive layer 1, A printing layer may be provided. The printing layer is formed by general printing methods conventionally used for printing on polymer films and paper using various printing inks such as gravure ink, flexographic ink, offset ink, stencil ink, and inkjet ink.

Examples of the base material 1 used in configurations (2) and (3) include MDOPE film, OPE film, OPP film, PET film, paper, and the like. The adhesive layer 1 is a cured coating film of the adhesive of the present invention. Examples of unstretched metal-deposited films include CPP films, LLDPE films, and VM-CPP films and VM-LLDPE films obtained by subjecting a gas-barrier heat seal film to metal deposition such as aluminum. An OPE film, a VM-MDOPE film obtained by subjecting an OPP film to vapor deposition of metal such as aluminum, a VM-OPE film, and a VM-OPP film can be used. A printed layer may be provided on either side of the substrate 1 in the same manner as in configuration (1).

Examples of transparent vapor-deposited stretched films used in configuration (4) include films obtained by vapor-depositing silica or alumina on MDOPE films, OPE films, OPP films, PET films, nylon films, and the like. For the purpose of protecting the inorganic deposition layer of silica or alumina, etc., a film obtained by coating the deposition layer may be used. The adhesive layer 1 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those of the configuration (1). A printed layer may be provided on the adhesive layer 1 side of the transparent vapor deposited stretched film (when using a film having a coated inorganic vapor deposited layer, the surface of the coating layer on the adhesive layer 1 side). The method of forming the printed layer is the same as that of configuration (1).

Examples of the base material 1 used in configuration (5) include PET film, paper, and the like. Examples of the base material 2 include a nylon film and 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 of the configuration (1). A printed layer may be provided on either side of the substrate 1 in the same manner as in configuration (1).

As the base material 1 of configuration (6), the same ones as those of configurations (2) and (3) can be mentioned. Examples of the metallized stretched film include MDOPE film, OPE film, OPP film, VM-MDOPE film obtained by vapor-depositing metal such as aluminum on PET film, VM-OPE film, VM-OPP film and VM-PET film. 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 of the configuration (1). A printed layer may be provided on either side of the substrate 1 in the same manner as in configuration (1).

Examples of the base material 1 of configuration (7) include PET film, paper, and the like. Examples of the transparent vapor-deposited stretched film include those similar to those of the configuration (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 of the configuration (1). A printed layer may be provided on either side of the substrate 1 in the same manner as in configuration (1).

Examples of the base material 1 of configuration (8) include PET film, paper, and the like. Aluminum foil etc. are mentioned as a metal layer. 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 of the configuration (1). A printed layer may be provided on either side of the substrate 1 in the same manner as in configuration (1).

Examples of the base material 1 of configurations (9) and (10) include PET film, paper, and the like. Examples of the base material 2 include a nylon film and the like. Aluminum foil etc. are mentioned as a metal layer. At least one of the adhesive layers 1, 2 and 3 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those of the configuration (1). A printed layer may be provided on either side of the substrate 1 in the same manner as in configuration (1).

When the adhesive of the present invention is a solvent type, the adhesive of the present invention is applied to the film material that will be the substrate using a roll such as a gravure roll, and the organic solvent is volatilized by heating in an oven or the like. The laminate of the present invention is obtained by laminating the other base material. It is preferable to perform an aging treatment after lamination. The aging temperature is preferably room temperature to 80° C., and the aging time is preferably 12 to 240 hours.

When the adhesive of the present invention is solvent-free, after applying the adhesive of the present invention that has been preheated to about 40° C. to 100° C. to the base film material using a roll such as a gravure roll. , the other substrate is immediately laminated to obtain the laminate of the present invention. It is preferable to perform an aging treatment after lamination. The aging temperature is preferably room temperature to 70° C., and the aging time is preferably 6 to 240 hours.

The amount of adhesive to be applied is appropriately adjusted. In the case of a solvent-based adhesive, for example, the solid content is adjusted to 1 g/m ² or more and 10 g/m ² or less, preferably 2 g/m 2 ^or more and 5 g/m ² or less. In the case of a solventless adhesive, the coating amount of the adhesive is, for example, 1 g/m ² or more and 5 g/m ² or less, preferably 1 g/m ^{2 or} more and 3 g/m ² or less.

The laminate of the present invention may further contain other films and substrates in addition to the above-described configurations (1) to (10). As other substrates, in addition to the stretched film, unstretched film, and transparent vapor-deposited film described above, porous substrates such as paper, wood, and leather, which will be described later, can also be used. The adhesive used when bonding other substrates may or may not be the adhesive of the present invention.

"Other layers" may contain known additives and stabilizers, such as antistatic agents, easy-adhesion coating agents, plasticizers, lubricants, and antioxidants. In addition, the "other layers" are pre-treated with corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, etc. in order to improve adhesion when laminated with other materials. may

The laminate of the present invention can be used in various applications, such as packaging materials for foods, pharmaceuticals, and daily necessities, lids, paper straws, paper napkins, paper spoons, paper plates, paper cups and other paper tableware, barrier materials, and roofs. materials, solar cell panel materials, battery packaging materials, window materials, outdoor flooring materials, lighting protection materials, automotive parts, signboards, outdoor industrial applications such as stickers, decorative sheets used for injection molding simultaneous decoration methods, etc. It can be suitably used as packaging materials for liquid laundry detergents, liquid kitchen detergents, liquid bath detergents, liquid bath soaps, liquid shampoos, liquid conditioners, and the like.

Since the laminate of the present invention is excellent in heat resistance and deformation relaxation, it can be particularly suitably used for applications requiring these properties. Applications in which a laminate having an adhesive layer having heat resistance and deformation relaxation properties are suitably used include packaging materials for boiling and retorting. Applications in which the laminate having an adhesive layer with heat resistance is preferably used include automotive interior materials and heat-dissipating sheet members. PTP packaging and the like are examples of applications in which a laminate having an adhesive layer having deformation relaxation properties is preferably used.

When the retort treatment is performed, if the Ny film and the aluminum foil are laminated together with an adhesive layer interposed therebetween, separation between these layers is likely to occur. Therefore, by bonding a Ny film and an aluminum foil together using the adhesive of the present invention, a laminate having excellent retort resistance can be obtained.

More specific structural examples include PET film/Ny film/aluminum foil/CPP film, PET film/aluminum foil/Ny film/CPP film, Ny film/aluminum foil/Ny film/CPP film, and the like. A film and an aluminum foil are laminated using the adhesive of the present invention. Other films may be laminated using a general-purpose adhesive, or may be laminated using the adhesive of the present invention. It goes without saying that a printing layer may be provided at an appropriate position of the laminate.

<Packaging material>
The laminate of the present invention can be used as a multilayer packaging material for the purpose of protecting foods, medicines, and the like. When used as a multilayer packaging material, the layer structure may vary depending on the contents, usage environment, and usage pattern. Moreover, the package of the present invention may be appropriately provided with an easy-opening treatment or a resealing means.

The packaging material of the present invention is obtained by using the laminate of the present invention, superimposing the sealant film surfaces of the laminate on each other, and then heat-sealing the peripheral edges to form a bag. As a bag-making method, the laminate of the present invention is folded or overlapped so that the inner layer surface (sealant film surface) faces each other, and the peripheral edge is sealed, for example, by a side seal type, a two-sided seal type, There are three-sided seal type, four-sided seal type, envelope pasted seal type, palm pasted seal type, pleated seal type, flat bottom seal type, square bottom seal type, gusset type, and other heat seal methods. be done. The packaging material of the present invention can take various forms depending on the contents, environment of use, and form of use. A self-supporting packaging material (standing pouch) or the like is also possible. As a heat sealing method, known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing and ultrasonic sealing can be used.

After the packaging material of the present invention is filled with contents through its opening, the opening is heat-sealed to manufacture a product using the packaging material of the present invention. Examples of filling contents include foods such as rice confectionery, bean confectionery, nuts, biscuits and cookies, wafer confectionery, marshmallows, pies, half-baked cakes, candy, snacks, bread, snack noodles, and instant noodles. , dried noodles, pasta, aseptic packaged rice, rice porridge, rice porridge, packaged mochi, staples such as cereal foods, pickles, boiled beans, natto, miso, frozen tofu, tofu, mushrooms, konjac, processed wild plants, jams, peanut cream, Salads, frozen vegetables, processed agricultural products such as potato processed products, hams, bacon, sausages, processed chicken products, processed livestock products such as corned beef, fish hams and sausages, fish paste products, kamaboko, seaweed, tsukudani, Processed marine products such as bonito flakes, salted fish, smoked salmon, and mustard cod roe; fruits such as peaches, oranges, pineapples, apples, pears, and cherries; vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes. , hamburgers, meatballs, fried seafood, gyoza, croquettes, and other frozen and chilled prepared foods; butter, margarine, cheese, cream; instant creamy powder; Foods such as seasonings, retort pouch curry, and pet food can be mentioned.

Non-food items include cigarettes, disposable body warmers, medicines such as infusion packs, liquid laundry detergents, liquid kitchen detergents, liquid bath detergents, liquid bath soaps, liquid shampoos, liquid conditioners, cosmetics such as lotions and milky lotions, and vacuum cleaners. It can also be used as various packaging materials such as heat insulators, batteries and the like.

The present invention will be described in more detail below with specific synthesis examples and examples, but the present invention is not limited to these examples. In the following examples, "parts" and "%" represent "mass parts" and "mass%", respectively, unless otherwise specified.

<Preparation of polyol composition (Y)>
(Synthesis Example 1) Polyester polyol (B1-1)
Ethylene glycol: 6.4 parts, neopentyl glycol: 22.3 parts, 1,6-hexanediol: 9.9 parts, isophthalate were added to a polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a Snyder tube, and a condenser. Acid: 17.3 parts, terephthalic acid: 21.3 parts, adipic acid: 11.9 parts, monomer acid: 0.2 parts, dimer acid: 6.4 parts, trimer acid: 1.3 parts, tetramer acid: 0.2 parts of titanium tetraisopropoxide and 10 ppm of titanium tetraisopropoxide were charged, and the inside temperature was maintained at 260°C by gradually heating so that the temperature at the top of the rectifying tube did not exceed 100°C. After the acid value fell below the specified value, the reaction was continued for an additional hour. The pressure was reduced to 30 mmHg and held for 3 hours to obtain an intermediate polyester polyol having a solid content acid value of 0.6 mgKOH/g and a hydroxyl value of 20 mgKOH/g. Yield was 85%.

Isophorone diisocyanate: 2.4 parts by mass was added to 100 parts by mass of the obtained intermediate polyester polyol, and the mixture was heated to 50 to 90 ° C. to perform a urethanization reaction until free NCO groups were substantially eliminated, and the hydroxyl value was A polyester polyurethane polyol of 8 mg KOH/g was obtained. This was diluted with ethyl acetate and 200 ppm of dibutyltin dilaurate was added to the polyester polyurethane polyol (solid content) to obtain a polyester polyol (B1-1) having a polyester polyurethane polyol solid content of 60%.

(Synthesis Example 2) Polyester polyol (B1-2)
Ethylene glycol: 8.2 parts, diethylene glycol: 7.3 parts, neopentyl glycol: 4.5 parts, 1,6-hexanediol were added to a polyester reaction vessel equipped with an agitator, a nitrogen gas inlet tube, a Snyder tube, and a condenser. : 18.1 parts, isophthalic acid: 9.1 parts, terephthalic acid: 27.2 parts, adipic acid: 8.2 parts, sebacic acid: 7.3 parts, monomer acid: 0.2 parts, dimer acid: 7 parts .4 parts, trimer acid: 1.3 parts, tetramer acid: 0.2 parts, and 10 ppm of titanium tetraisopropoxide are charged, and the inside temperature is lowered by gradually heating so that the temperature at the top of the rectification tube does not exceed 100 ° C. It was held at 260°C. After the acid value fell below the specified value, the reaction was continued for an additional hour. The pressure was reduced to 30 mmHg and held for 3 hours to obtain a polyester polyol (B1-2) having a solid content acid value of 0.6 mgKOH/g and a hydroxyl value of 12 mgKOH/g.

(Synthesis Example 3) Polyester polyol (B1-3)
Toluene diisocyanate: 0.4 parts by mass is added to 100 parts by mass of the polyester polyol (B1-2), and the mixture is heated to 50 to 90 ° C. to perform a urethanization reaction until free NCO groups are substantially eliminated, and the hydroxyl value is of 10 mg KOH/g was obtained. This was diluted with ethyl acetate and 200 ppm of dibutyltin dilaurate was added to the polyester polyurethane polyol (solid content) to obtain a polyester polyol (B1-3) having a polyester polyurethane polyol solid content of 60%.

<Preparation of adhesive>
(Example 1)
Carbodiimide-modified diphenylmethane diisocyanate (Lupranate MM-103B, manufactured by BASF INOAC Polyurethane), trimethylolpropane adduct of toluene diisocyanate (Desmodur L75, manufactured by Covestro), biuret of hexamethylene diisocyanate (Desmodur N3210A, manufactured by Covestro) , and polyester polyol (B1-1) in the formulation shown in Table 1 to prepare the adhesive of Example 1.

(Example 2) to (Example 6)
Adhesives of Examples 2 to 6 were prepared in the same manner as in Example 1 except that the polyisocyanate compounds (A1), (A2) and polyester polyol (B1) used and their formulations were changed to those shown in Tables 1 and 2. was prepared. The allophanate form of hexamethylene diisocyanate in the table is Duranate D101 manufactured by Asahi Kasei Corporation.

(Comparative Example 1), (Comparative Example 2)
Adhesives of Comparative Examples 1 and 2 were prepared in the same manner as in Example 1 except that the polyisocyanate compounds (A1), (A2) and polyester polyol (B1) used and their formulations were changed to those shown in Table 2.

The compounding amount in the table is the solid content amount, and (A1) / ((A1) + (A2)) is the ratio of the polyisocyanate compound (A1) to the total amount of the polyisocyanate compounds (A1) and (A2) ( % by mass), and [NCO]/[OH] is the molar ratio between the isocyanate groups contained in the polyisocyanate composition (X) and the hydroxyl groups contained in the polyol composition (Y).

<Production of laminate>
(Manufacturing of laminate)
Each of the adhesives of Examples and Comparative Examples was applied to a PET film having a thickness of 12 μm using a bar coater so that the coating amount was 3.5 g/m ² (solid content), and dried by volatilizing ethyl acetate with a dryer. . Next, the adhesive was laminated to a stretched nylon film having a thickness of 15 μm.
Subsequently, the adhesive of Example or Comparative Example was applied to the nylon surface of the laminate so that the coating amount was 3.5 g/m ² (solid content), and dried by volatilizing ethyl acetate with a dryer set at a temperature of 70 degrees. . An adhesive and an aluminum foil having a thickness of 9 μm were pasted together.

Subsequently, the adhesive of Examples or Comparative Examples was applied to the aluminum foil surface of the laminate so that the coating amount was 3.5 g/m ² (solid content), and dried by volatilizing ethyl acetate with a dryer set at a temperature of 70 degrees. bottom. An adhesive and a CPP film with a thickness of 70 μm were laminated together. Aging was performed at 40° C. for 3 days to obtain a laminate.

<Evaluation>
(normal state adhesive strength)
Using a tensile tester in an atmosphere of 25° C., the peeling speed was set to 300 mm/min, and the adhesive strength (N/15 mm) between the nylon film and aluminum of the laminate was measured by the T-type peeling method. The results are summarized in Tables 1 and 2.
(hot adhesive strength)
Using a tensile tester in an atmosphere of 100° C., the peeling speed was set to 3 mm/min, and the adhesive strength (N/15 mm) between the nylon film and aluminum of the laminate was measured without measuring angles. The results are summarized in Tables 1 and 2.

(Retort resistance)
A test piece was cut out from the laminate, folded with the CPP film facing inward, and heat-sealed on three sides with a width of 10 mm other than the fold. Next, a cut (notch) of 1.5 mm was provided at an arbitrary portion of the heat-sealed end to prepare a test piece. Twenty test pieces prepared in the same manner were placed near the hot water shower nozzle of a shower retort sterilizer (Flavor Ace, manufactured by Hisaka Seisakusho) so that the notch of each test piece was positioned, and the temperature was maintained at 135 ° C. for 30 minutes. The retort treatment was performed under the conditions of The state of the test piece after retorting was evaluated as follows and summarized in Tables 1 and 2.
5: Less than 3 peels with a major diameter of 1 mm or less 4: 3 or more and less than 5 peels with a major diameter of 1 mm or less 3: 5 or more and less than 10 peels with a major diameter of 1 mm or less 2: Peeling with a major diameter of 1 mm or less 10 or more, or less than 5 peels exceeding 1 mm 1: 5 or more peels with a major diameter exceeding 1 mm

As is clear from the table, the adhesive of the present invention was excellent in normal state adhesive strength, hot adhesive strength, and retort resistance. On the other hand, the adhesives of Comparative Examples were inferior in retort resistance to the adhesives of Examples.

Claims (11)

Containing a polyisocyanate composition (X) and a polyol composition (Y),
The polyisocyanate composition (X) contains a bifunctional polyisocyanate compound (A1) and a trifunctional or higher polyisocyanate compound (A2),
The polyol composition (Y) contains a polyester polyol (B1),
A two-liquid curable adhesive in which the content of the polyisocyanate compound (A1) in the total amount of the polyisocyanate compound (A1) and the polyisocyanate compound (A2) is 5 to 50% by mass. The two-component curing adhesive according to claim 1, wherein at least one of the polyisocyanate compound (A1) and the polyisocyanate compound (A2) contains an aromatic polyisocyanate. The two-component curing adhesive according to any one of claims 1 and 2, wherein at least one of the polyisocyanate compound (A1) and the polyisocyanate compound (A2) contains an aliphatic polyisocyanate. The two-component curing adhesive according to any one of claims 1 to 3, wherein the polyester polyol (B1) has a number average molecular weight of 1,000 or more and 50,000 or less. 5. The polyester polyol (B1) according to any one of claims 1 to 4, which is a reaction product of a monomer composition containing a polyhydric carboxylic acid and a polyhydric alcohol, and wherein the polyhydric carboxylic acid contains a tetramer acid. 2-liquid curable adhesive. Any one of claims 1 to 5, wherein the polyester polyol (B1) is a reaction product of a monomer composition containing a polyhydric carboxylic acid and a polyhydric alcohol, and the polyhydric carboxylic acid contains an aromatic polyhydric carboxylic acid. The two-component curing adhesive according to item 1. The two-component curing adhesive according to any one of claims 1 to 6, wherein the polyester polyol (B1) is a polyester polyurethane polyol. The molar ratio ([NCO]/[OH]) between the isocyanate groups contained in the polyisocyanate composition (X) and the hydroxyl groups contained in the polyol composition (Y) is 1.0 to 4.0. The two-part curable adhesive according to any one of claims 1 to 7. a first substrate;
a second substrate;
an adhesive layer that bonds the first base material and the second base material together,
A laminate in which the adhesive layer is a cured product of the adhesive according to any one of claims 1 to 8. The laminate according to claim 9, wherein the first base material is made of aluminum and the second base material is made of nylon. A packaging material comprising the laminate according to any one of claims 9 and 10.