CN117897462A - Adhesive, laminate, and packaging material - Google Patents

Abstract

The invention provides a 2-liquid curing adhesive which has high PAA reduction speed and excellent storage stability. The present invention is a 2-liquid curable adhesive comprising an isocyanate composition (X) containing a urethane prepolymer which is a reaction product of an isocyanate composition (i) and a polyol composition (ii), a biuret derivative of 4,4' -MDI, and a urea derivative of 4,4' -MDI, wherein the content of 4,4' -MDI in the isocyanate composition (i) is 75.0 mass% or more, the content of 2,2' -MDI is 0.5 mass% or less, the content of 2,4' -MDI is 5.0 mass% or less, and the content of the biuret derivative in the isocyanate composition (X) is 0.4 mass% or more and 20.0 mass% or less, and the content of the biuret derivative is 1.0 times or more of the content of the urea derivative.

Description

Adhesive, laminate, and packaging material

Technical Field

The present invention relates to a 2-liquid curable adhesive, a laminate, and a packaging material.

Background

Laminates used for various packaging materials, labels, and the like are provided with design properties, functionality, storage properties, convenience, transportation resistance, and the like by lamination of various and various plastic films, metal foils, paper, and other substrates. A packaging material obtained by forming the laminate into a bag is used as a packaging material for foods, medicines, detergents, and the like.

Conventionally, a laminate used for a packaging material has been mainly obtained by a dry lamination method in which an adhesive (sometimes referred to as a solvent-based laminating adhesive) dissolved in a volatile organic solvent is applied to a base material, the organic solvent is volatilized while passing through an oven, and a separate base material is bonded thereto, but in recent years, a demand for a reactive type 2 liquid-based laminating adhesive (hereinafter referred to as a solvent-free adhesive) containing no volatile organic solvent has also been increasing from the viewpoints of reducing environmental load and improving working environment (patent document 1).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2014-159548

Disclosure of Invention

Problems to be solved by the invention

When a laminate for food packaging is produced using such a 2-liquid urethane adhesive, there are cases where the isocyanate monomer remaining in the adhesive layer becomes a problem. When the aromatic isocyanate monomer remains in the adhesive layer, it reacts with water present in the surroundings to become an aromatic primary amine (PAA). The PAA produced may migrate in the membrane and dissolve out into the contents (food). The european commission has set various restrictions in terms of regulations concerning plastic materials and products for food contact, such as the detection limits thereof, due to concerns about the harmfulness of PAA to the human body.

The PAA generated by the reaction of the aromatic isocyanate and water reacts further with water, so that even when the aromatic isocyanate remains in the adhesive layer, the concentration of PAA gradually decreases, eventually being smaller than the detection limit. In the case of producing a laminate for food packaging, it is preferable that the PAA concentration is reduced at a high rate. From this viewpoint, it is preferable that the isocyanate component of the adhesive is made of 4,4' -diphenylmethane diisocyanate having relatively excellent reactivity. However, the urethane prepolymer containing 4,4' -diphenylmethane diisocyanate in a high content has a high crystallinity, and the urethane prepolymer is crystallized and clouded during storage even at room temperature, and thus has poor storage stability.

The present invention has been made in view of such circumstances, and an object thereof is to provide a 2-liquid curable adhesive which has a high PAA reduction rate and is excellent in storage stability.

Means for solving the problems

The present invention relates to a 2-liquid curable adhesive comprising an isocyanate composition (X) and a polyol composition (Y) comprising a polyol compound, wherein the isocyanate composition (X) comprises a urethane prepolymer which is a reaction product of the isocyanate composition (i) and the polyol composition (ii), a biuret derivative of 4,4' -diphenylmethane diisocyanate and a urea derivative of 4,4' -diphenylmethane diisocyanate, the content of 4,4' -diphenylmethane diisocyanate in the isocyanate composition (i) is 75.0 mass% or more, the content of 2,2' -diphenylmethane diisocyanate is 0.5 mass% or less, the content of 2,4' -diphenylmethane diisocyanate is 5.0 mass% or less, the content of the biuret derivative is 0.4 mass% or more and 20.0 mass% or less, and the content of the biuret derivative is 1.0 times or more of the content of the urea derivative.

Effects of the invention

The adhesive of the present invention can provide a 2-liquid curable adhesive which has a high PAA reduction rate and excellent storage stability.

Detailed Description

< adhesive >

The adhesive of the present invention is a 2-liquid curable adhesive comprising a polyisocyanate composition (X) and a polyol composition (Y). The adhesive of the present invention will be described in detail below.

(polyisocyanate composition (X))

The polyisocyanate composition (X) used in the adhesive of the present invention contains a urethane prepolymer, which is a reaction product of the isocyanate composition (i) and the polyol composition (ii), a biuret derivative of 4,4'-MDI (hereinafter referred to as biuret derivative) and a urea derivative of 4,4' -MDI (hereinafter referred to as urea derivative), and in the isocyanate composition (i), the content of 4,4 '-diphenylmethane diisocyanate (hereinafter referred to as 4,4' -MDI) is 75.0 mass% or more, the content of 2,2 '-diphenylmethane diisocyanate (hereinafter referred to as 2,2' -MDI) is 0.5 mass% or less, the content of 2,4 '-diphenylmethane diisocyanate (hereinafter referred to as 2,4' -MDI) is 5.0 mass% or less, the content of the biuret derivative is 0.4 mass% or more and 20.0 mass% or less of the total amount of the polyisocyanate composition (X), and the content of the biuret derivative (mass%) is 1.0 times or more the content of the urea derivative (mass%).

Since such urethane prepolymer is synthesized using 4,4' -MDI having excellent reactivity as a main component, the rate of PAA reduction is high, and thus the urethane prepolymer is particularly suitable for the production of laminates for food packaging. The blending amount of 4,4' -MDI in the isocyanate composition (i) is more preferably 80 mass% or more. The 2,2'-MDI and 2,4' -MDI have low reactivity as compared to 4,4'-MDI, and the PAA reduction rate is relatively slow, so that the content thereof is preferably small, but may be mixed in as impurities during synthesis and separation of 4,4' -MDI. If the content is at the above level, the reduction rate of PAA is not greatly affected.

Further, when the biuret derivative and the urea derivative are contained in the above-mentioned ranges, a urethane prepolymer having excellent storage stability, in which the occurrence of crystallization and cloudiness is suppressed, can be obtained. If the content of the biuret derivative is less than 0.4 mass%, the effect of suppressing crystallization and clouding of the urethane prepolymer is weak, and if it exceeds 20.0 mass%, the viscosity of the urethane prepolymer becomes high and the coating suitability is poor. If the content of the biuret derivative is less than 1.0 times the content of the urea derivative, the effect of suppressing cloudiness becomes weak. The upper limit of the ratio of the amount of the biuret derivative to the amount of the urea derivative is not particularly limited, but is, for example, 10 times or less the amount of the urea derivative.

The method of introducing the urea derivative and the biuret derivative into the isocyanate composition (X) includes: a method of using a composition comprising a urea derivative, a biuret derivative as isocyanate composition (i); a method of synthesizing a polyol composition (ii) simultaneously with urethanization by controlling a reaction temperature using a composition containing water and an amine compound; a method of adding a urea derivative or a biuret derivative to a urethane prepolymer which is a reaction product of the isocyanate composition (i) and the polyol composition (ii), and the like, but the method is not limited thereto.

The urea derivative can be synthesized, for example, by reacting 4,4' -MDI with water and/or an amine compound at about 65 to 85 ℃. The biuret derivative can be synthesized, for example, by reacting a urea derivative with 4,4' -MDT at about 95 to 110 ℃. Examples of amine compounds that can be suitably used for the synthesis of urea derivatives and biuret derivatives include monoprimary amine compounds and monoprimary amine compounds described below.

The isocyanate composition (i) used for the synthesis of the urethane prepolymer may contain an isocyanate compound other than 4,4' -MDT, 2' -MDI, and 2,4' -MDT. The isocyanate compound used in combination with these isocyanates is preferably a non-aromatic isocyanate compound such as an aromatic aliphatic diisocyanate, an alicyclic diisocyanate, or a derivative thereof (biuret, allophanate, adduct, allophanate) or the like.

The aromatic aliphatic diisocyanate means an aliphatic isocyanate having 1 or more aromatic rings in the molecule, and examples thereof include meta-xylylene diisocyanate (alias: XDT), alpha' -tetramethylxylylene diisocyanate (alias: TMXDT), and the like, but are not limited thereto.

Examples of the aliphatic diisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (also referred to as HDI), pentamethylene diisocyanate, 1, 2-propylene diisocyanate, 2, 3-butylene diisocyanate, 1, 3-butylene diisocyanate, dodecamethylene diisocyanate, and 2, 4-trimethylhexamethylene diisocyanate, but are not limited thereto.

Examples of the alicyclic diisocyanate include 3-isocyanatomethyl-3, 5-trimethylcyclohexyl isocyanate, isophorone diisocyanate (referred to as TPDI), 1, 3-cyclopentanediisocyanate, 1, 3-cyclohexanediisocyanate, 1, 4-cyclohexanediisocyanate, methyl-2, 6-cyclohexanediisocyanate, 4' -methylenebis (cyclohexylisocyanate), and 1, 4-bis (isocyanatomethyl) cyclohexane, but are not limited thereto.

When the isocyanate composition (i) contains a non-aromatic isocyanate, the blending amount is preferably 20 mass% or less of the total amount of the isocyanate composition (i) from the viewpoint of the reaction rate of the adhesive and the like.

The polyol composition (ii) used in the synthesis of the urethane prepolymer contains a polyol compound. The polyol compound is not particularly limited, and a compound generally used for the synthesis of a urethane prepolymer can be suitably used. Examples thereof include: diols such as ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 2-methyl-1, 3-propylene glycol, 1, 4-butanediol, 1, 5-pentanediol, 3-methyl-1, 5-pentanediol, 1, 6-hexanediol, neopentyl glycol, dimethylbutanol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bis (hydroxyethoxy) benzene, 1, 4-cyclohexanediol, and 1, 4-cyclohexanedimethanol;

3-functional or 4-functional aliphatic alcohols such as glycerin, trimethylolpropane and pentaerythritol;

bisphenol such as bisphenol a, bisphenol F, hydrogenated bisphenol a, and hydrogenated bisphenol F; dimer diol (dimer diol);

polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, phenyl ethylene oxide, epichlorohydrin, tetrahydrofuran, cyclohexene, and the like, in the presence of a polymerization initiator, such as the above-mentioned diols, 3-functional or 4-functional aliphatic alcohols, and the like;

Polyether urethane polyol obtained by further subjecting a polyether polyol to a high molecular weight polymerization with an isocyanate compound;

a polyester polyol (1) which is a reactant of a polyester obtained by ring-opening polymerization of a cyclic ester compound such as propiolactone, butyrolactone, epsilon-caprolactone, sigma-valerolactone, beta-methyl-sigma-valerolactone, etc., and a polyol such as the above-mentioned diol, glycerol, trimethylolpropane, pentaerythritol, etc.;

polyester polyol (2) obtained by reacting the diol, dimer diol, or 2-functional polyol such as bisphenol with a polycarboxylic acid:

polyester polyol (3) obtained by reacting 3-functional or 4-functional aliphatic alcohol with polycarboxylic acid;

a polyester polyol (4) obtained by reacting a 2-functional polyol with the 3-functional or 4-functional aliphatic alcohol and a polycarboxylic acid;

a polyester polyol (5) which is a polymer of a hydroxy acid such as dimethylolpropionic acid or castor oil fatty acid;

polyester polyether polyurethane polyol obtained by reacting at least one of the polyester polyols (1) to (5) with a polyether polyol and an isocyanate compound;

polyester polyurethane polyols obtained by polymerizing the polyester polyols (1) to (5) with an isocyanate compound;

castor oil, dehydrated castor oil, hydrogenated castor oil which is a hydrogenated product of castor oil, castor oil-based polyols such as 5 to 50 mol adducts of alkylene oxides of castor oil, and the like, and mixtures thereof.

Examples of the polycarboxylic acid used for the synthesis of the polyester polyols (2) to (4) include: aromatic polybasic acids such as phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1, 4-naphthalenedicarboxylic acid, 2, 5-naphthalenedicarboxylic acid, 2, 6-naphthalenedicarboxylic acid, 2, 3-naphthalenedicarboxylic anhydride, naphthalenedicarboxylic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, diphthalic acid, 1, 2-bis (phenoxy) ethane-p, p' -dicarboxylic acid, benzophenone tetracarboxylic dianhydride, isophthalic acid-5-sodium sulfonate, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, and the like;

methyl esters of aromatic polybasic acids such as dimethyl terephthalate and dimethyl 2, 6-naphthalate;

aliphatic polybasic acids such as malonic acid, succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic anhydride, and itaconic acid;

alkyl esters of aliphatic polybasic 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;

Alicyclic polybasic acids such as 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, nadic anhydride (Japanese (Qihai) and chlorobridge anhydride; and the like, 1 kind or 2 or more kinds may be used in combination.

As the non-aromatic isocyanate among the isocyanate compounds used for the synthesis of the polyurethane polyol, the same compounds as those usable for the isocyanate composition (i) can be used. Examples of the aromatic isocyanate include 2,2' -diphenylmethane diisocyanate, 2,4' -diphenylmethane diisocyanate, 4' -diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate (also referred to as polymeric MDI or crude MDI), 1, 3-phenylene diisocyanate, 4' -diphenylmethane diisocyanate, 1, 4-phenylene diisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4' -toluidine diisocyanate, 2,4, 6-triisocyanate toluene, 1,3, 5-triisocyanate benzene, dianisidine diisocyanate, 4' -diphenyl ether diisocyanate, 4',4 "-triphenylmethane triisocyanate, and derivatives (biuret, allophanate, adduct, allophanate) of these diisocyanates, but are not limited thereto.

The polyol compound preferably comprises at least one of a polyether polyol or a polyester polyol.

The number average molecular weight of the polyol compound is not particularly limited, and is preferably 300 to 4000 as an example. The number average molecular weight in the present specification is a value measured by Gel Permeation Chromatography (GPC) under the following conditions.

Measurement device: HLC-8320GPC manufactured by TOSOH Co., ltd

Chromatographic column: TSKgel 4000HXL, TSKgel 3000HXL, TSKgel 2000HXL, TSKgel 1000HXL manufactured by TOSOH Co., ltd

A detector: RI (differential refractometer)

And (3) data processing: multi Station GPC-8020model II manufactured by TOSOH Co., ltd

Measurement conditions: chromatographic column temperature 40 DEG C

Solvent tetrahydrofuran

Flow rate 0.35 ml/min

Standard: monodisperse polystyrene

Sample: a sample (100. Mu.l) obtained by filtering a tetrahydrofuran solution having a mass% of 0.2% in terms of resin solid content with a microfilter was used.

When the urea derivative or the biuret derivative is introduced into the urethane prepolymer by adding water to the polyol composition (ii), the water content of the polyol composition (ii) is preferably 0.01 mass% or more and 0.5 mass% or less. Thus, even when synthesis is performed using 4,4' -MDI as a main component, a urethane prepolymer excellent in storage stability without crystallization and cloudiness can be obtained. When the water content of the polyol composition is small, water may be added. When the water content of the polyol is high, the polyol is heated to 80-100 ℃ and dehydrated under reduced pressure.

The amine compound used in the case of introducing the urea derivative or the biuret derivative into the urethane prepolymer by using the amine compound in the polyol composition (ii) also preferably contains a monoprimary amine compound or a monoprimary amine compound. Thus, even when synthesis is performed using 4,4' -MDI as a main component, a urethane prepolymer which is free from crystallization, is cloudy, has excellent storage stability, and has a viscosity suitable for film lamination can be produced.

Examples of the monoprimary amine compound include aliphatic unsaturated primary amines such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, pentylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine (laurylamine), tri (dodecylamine), tetradecylamine (myristylamine), pentadecylamine, hexadecylamine, stearylamine, oleylamine, cocoalkylamine, tallow alkylamine, hydrogenated tallow alkylamine, allylamine, and the like, aniline, and benzylamine.

Examples of the monoamine compound include aliphatic unsaturated secondary amines such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, dipentamine, and diallylamine, methylaniline, ethylaniline, dibenzylamine, diphenylamine, dicarballylamine, dihydrotallow alkylamine, distearylamine, and the like.

The amount of the monoamine compound blended is preferably 40 mass% or less of the total amount of the polyol composition (ii) from the viewpoint of balance between crystallization of the urethane prepolymer and inhibition of cloudiness and reactivity of the adhesive.

The isocyanate composition (i) and the polyol composition (ii) are reacted under a condition that the isocyanate groups contained in the isocyanate groups (i) are excessive relative to the active hydrogen groups contained in the polyol composition (ii), to obtain a urethane prepolymer. The equivalent ratio [ NCO ]/[ active hydrogen groups ] of isocyanate groups to active hydrogen groups contained in the polyol composition (ii) may be appropriately adjusted depending on the purpose, and is, for example, 2.0 to 20.0.

The synthesized urethane prepolymer may be used as it is, or may be further added with an isocyanate compound to adjust the viscosity. Examples of the isocyanate compound include non-aromatic isocyanates, derivatives thereof, urethane prepolymers obtained from non-aromatic isocyanates and polyols, carbodiimide-modified diphenylmethane diisocyanate, allophanate-modified diphenylmethane diisocyanate, and polymeric diphenylmethane diisocyanate.

As the non-aromatic isocyanate and its derivative, the same compounds as exemplified as the compounds that can be used in combination in the isocyanate composition (i) can be used. As the polyol used in the synthesis of the urethane prepolymer obtained from the non-aromatic isocyanate and the polyol, the same polyol as exemplified as the polyol compound used in the polyol composition (ii) can be used.

Carbodiimide-modified diphenylmethane diisocyanate, allophanate-modified diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate generally comprise diphenylmethane diisocyanate as a monomer. In the present invention, a substance having a 2,2'-MDI content of 2.0 mass% or less and a 2,4' -MDI content of 5.0 mass% or less is used.

In the case where the adhesive of the present invention is used in the form of a solvent-free type, the viscosity of the polyisocyanate composition (X) is adjusted to a range suitable for the solvent-free lamination method. For example, the viscosity at 25℃is adjusted to a range of 1000 to 10000mPas, more preferably 1000 to 5000 mPas. The viscosity of the polyisocyanate composition (X) can be adjusted by using the blending amount of the urethane prepolymer and the isocyanate monomer, for example.

(polyol composition (Y))

The polyol composition (Y) contains a polyol compound having a plurality of hydroxyl groups. As the polyol compound, the same polyol compounds as exemplified as the polyol compound usable in the polyol composition (ii) can be used. Preferably at least one of polyester polyol, polyether polyol and castor oil polyol.

In the case where the adhesive of the present invention is used in the solvent-free form, the viscosity of the polyol composition (Y) is adjusted to a range suitable for the solvent-free lamination method. For example, the viscosity at 40℃is adjusted to be in the range of 100 to 5000mPas, more preferably 100 to 3000 mPas. The viscosity of the polyol composition (Y) can be adjusted by using the skeleton of the polyol compound, a plasticizer described later, and the like. In the case of adjusting the skeleton of the polyol compound, the viscosity can be reduced by using, for example, polypropylene glycol or polyester polyol obtained by the reaction of aliphatic carboxylic acid and polyol. Alternatively, the viscosity may be increased by using a polyester polyol obtained by the reaction of an aromatic carboxylic acid with a polyol.

(other component of adhesive)

The adhesive of the present invention may contain components other than the above components. The other components may be contained in either or both of the polyisocyanate composition (X) and the polyol composition (Y), or may be prepared separately therefrom and used after being mixed with the polyisocyanate composition (X) and the polyol composition (Y) immediately before the adhesive is applied. The components will be described below.

(catalyst)

Examples of the catalyst include metal catalysts, amine catalysts, and aliphatic cyclic amide compounds.

Examples of the metal catalyst include metal complex catalysts, inorganic metal catalysts, and organic metal catalysts. Examples of the metal complex catalyst include acetylacetonates of metals selected from Fe (iron), mn (manganese), cu (copper), zr (zirconium), th (thorium), ti (titanium), al (aluminum), and Co (cobalt), for example, iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, zirconium acetylacetonate, and the like.

Examples of the inorganic metal catalyst include catalysts selected from Sn, fe, mn, cu, zr, th, ti, al, co and the like.

Examples of the organometallic catalyst include zinc octoate, zinc neodecanoate, zinc naphthenate and other organozinc compounds, stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, dibutyltin dichloride and other organotin compounds, nickel octoate, nickel naphthenate and other organonickel compounds, cobalt octoate, cobalt naphthenate and other organocobalt compounds, bismuth octoate, bismuth neodecanoate, bismuth naphthenate and other organobismuth compounds, tetraisopropoxy titanate, dibutyltitanium dichloride, tetrabutyltitanate, titanium butoxide, titanium trichloride, and titanium chelate complexes containing at least 1 of aliphatic diketones, aromatic diketones and alcohols having 2 to 10 carbon atoms as ligands.

Examples of the amine-based catalyst include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, 2-methylquinuclidine, N, N, N ', N' -tetramethylethylenediamine, N, N, N ', N' -tetramethylpropylenediamine, N, N ', N' -pentamethyldiethylenetriamine, N, N, N ', N' -pentamethyldiisopropylenediamine, 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) propylenediamine, bis (dimethylaminopropyl) amine, bis (dimethylaminopropyl) isopropanolamine, 3-quininol, 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-methylimidazole, 1, 2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropyl imidazole, N-dimethylhexylamine, 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.

Examples of the aliphatic cyclic amide compound include delta-valerolactam, epsilon-caprolactam, omega-enantholactam, eta-caprylolactam, beta-propiolactam and the like. Of them epsilon caprolactam is more effective in promoting cure.

(anhydride)

Examples of the acid anhydride include a cyclic aliphatic acid anhydride, an aromatic acid anhydride, and an unsaturated carboxylic acid anhydride, and 1 or 2 or more kinds of acid anhydrides may be used in combination. More specifically, examples thereof include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, dodecenyl succinic anhydride, polyadipic anhydride, polyazelaic anhydride, polysebacic anhydride, poly (ethyloctadecanedioic acid) anhydride, poly (phenylhexadecanedioic acid) anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylnadic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexenedicarboxylic anhydride, methylcyclohexenetetracarboxylic anhydride, ethylene glycol ditrimellitic anhydride, chlorobridge anhydride, nadic anhydride (Japanese: water of Indic acid), methylnadic anhydride, 5- (2, 5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexane-1, 2-dicarboxylic-1, 2,3, 4-tetrahydro-1-naphthalene dicarboxylic anhydride, 1-methyl-dicarboxyl-1, 2,3, 4-tetrahydronaphthalene dicarboxylic anhydride, and the like.

In addition, a compound obtained by modifying the above compound with a glycol may be used as the acid anhydride. Examples of diols that can be used for the modification include alkylene glycols such as ethylene glycol, propylene glycol, and neopentyl glycol: polyether glycols such as polyethylene glycol, polypropylene glycol and polytetramethylene ether glycol. Further, it is also possible to use copolymerized polyether glycol of 2 or more kinds of glycol and/or polyether glycol among them.

(coupling agent)

Examples of the coupling agent include silane coupling agents, titanate coupling agents, and aluminum coupling agents.

Examples of the silane coupling agent include aminosilanes such as γ -aminopropyl triethoxysilane, γ -aminopropyl trimethoxysilane, N- β (aminoethyl) - γ -aminopropyl trimethyldimethoxysilane, and N-phenyl- γ -aminopropyl trimethoxysilane: epoxysilanes such as beta- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, gamma-epoxypropoxypropyltrimethoxysilane, gamma-epoxypropoxypropyltriethoxysilane, etc.: vinyl silanes such as vinyl tris (. Beta. -methoxyethoxy) silane, vinyl triethoxysilane, vinyl trimethoxysilane and gamma-methacryloxypropyl trimethoxysilane: hexamethyldisilazane, gamma-mercaptopropyl trimethoxysilane, and the like.

Examples of the titanate-based coupling agent include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylglycol titanate, titanium lactate, and tetrastearyloxytitanium.

Examples of the aluminum-based coupling agent include aluminum acetoacetoxy diisopropoxide.

(pigment)

Examples of the pigment include, but are not limited to, extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, blue pigments, metal powder pigments, luminescent pigments, organic pigments such as pearl pigments, inorganic pigments, and plastic pigments described in 1970 edition (edited by the japan paint industry).

Examples of extender pigments include precipitated barium sulfate, fine powder, precipitated calcium carbonate, calcium bicarbonate, gypsum rubrum, alumina white, silica, hydrous fine silica (white carbon), ultrafine anhydrous silica (AEROSIL), silica sand (silica sand), talc, precipitated magnesium carbonate, bentonite, clay, kaolin, and loess.

Specific examples of the organic pigment include various insoluble azo pigments such as benzidine yellow, hansa yellow, lake red 4R, and the like; soluble azo pigments such as lake red C, carmine 6B, and date red 10; various (copper) phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; various alkaline dyeing lakes such as rhodamine lake and methyl violet lake; quinoline lake, fast sky blue, and the like; various vat dye-based pigments such as anthraquinone-based pigments, thioindigo-based pigments, and viol-based pigments; various quinacridone pigments such as bright noble color red B (Cinquasia Red B); various dioxazine pigments such as dioxazine violet; various condensed azo pigments such as solid and transparent; nigrosine, etc.

Examples of the inorganic pigment include various chromates such as chrome yellow, zinc chromate, and molybdenum orange; various ferricyanide compounds such as Prussian blue; various metal oxides such as titanium oxide, zinc white, brown yellow, iron oxide red, chromium oxide green, and zirconium oxide; cadmium yellow, cadmium red, mercury sulfide and other sulfides or selenides; various sulfates such as barium sulfate and lead sulfate; various silicates such as calcium silicate and ultramarine; various carbonates such as calcium carbonate and magnesium carbonate; various phosphates such as cobalt violet and manganese violet; various metal powder pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder and brass powder; these metallic flake pigments, mica-flake pigments; metal pigments such as mica-flake pigments and mica-like iron oxide pigments coated with metal oxides, and pearl pigments; graphite, carbon black, and the like.

Examples of the plastic pigment include "GRANDOLL PP-1000" and "PP-2000S" manufactured by DIC Co., ltd.

The pigment to be used may be appropriately selected depending on the purpose, and for example, it is preferable to use an inorganic oxide such as titanium oxide or zinc white as a white pigment and carbon black as a black pigment in view of excellent durability, weather resistance and design.

The amount of the pigment to be blended is, for example, 1 to 400 parts by mass, and more preferably 10 to 300 parts by mass, in order to improve the adhesion and blocking resistance, based on 100 parts by mass of the total amount of nonvolatile components of the polyol composition (X) and the polyisocyanate composition (Y).

(plasticizer)

Examples of the plasticizer include phthalic acid plasticizers, fatty acid plasticizers, aromatic polycarboxylic acid plasticizers, phosphoric acid plasticizers, polyol plasticizers, epoxy plasticizers, polyester plasticizers, and carbonate plasticizers.

Examples of the phthalic acid plasticizer include phthalic acid plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, diheptyl phthalate, di- (2-ethylhexyl) phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, didecyl phthalate, diisodecyl phthalate, ditridecyl phthalate, di-undecyl phthalate, dilauryl phthalate, distearyl phthalate, diphenyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, octyl decyl phthalate, dimethyl isophthalate, di- (2-ethylhexyl) isophthalate, and diisooctyl isophthalate; for example, a tetrahydrophthalate plasticizer such as di- (2-ethylhexyl) tetrahydrophthalate, di-n-octyl tetrahydrophthalate, and diisodecyl tetrahydrophthalate.

Examples of the fatty acid plasticizer include adipic acid plasticizers such as di-n-butyl adipate, di- (2-ethylhexyl) adipate, diisodecyl adipate, diisononyl adipate, di (C6-C10 alkyl) adipate, and di (butyl diglycol) adipate (Japanese text, line コ, line); azelaic acid plasticizers such as di-n-hexyl azelate, di- (2-ethylhexyl) azelate, diisooctyl azelate; sebacic acid plasticizers such as di-n-butyl sebacate, di- (2-ethylhexyl) sebacate, diisononyl sebacate, and the like; maleic acid plasticizers such as dimethyl maleate, diethyl maleate, di-n-butyl maleate, and di- (2-ethylhexyl) maleate; fumaric plasticizers such as di-n-butyl fumarate and di- (2-ethylhexyl) fumarate; itaconic acid plasticizers such as monomethyl itaconate, monobutyl itaconate, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, di- (2-ethylhexyl) itaconate; stearic acid plasticizers such as n-butyl stearate, glycerol monostearate, diethylene glycol distearate; oleic plasticizers such as butyl oleate, glycerol monooleate, diethylene glycol monooleate; citric acid plasticizers such as triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, acetyl tri- (2-ethylhexyl) citrate, and the like; ricinoleic acid plasticizers such as methyl acetylricinoleate, butyl acetylricinoleate, glycerol monoricinoleate, diethylene glycol monoricinoleate; other fatty acid plasticizers such as diethylene glycol monolaurate, diethylene glycol dipelargonate, pentaerythritol fatty acid ester, and the like.

Examples of the aromatic polycarboxylic acid plasticizer include trimellitic acid plasticizers such as tri-n-hexyl trimellitate, tri- (2-ethylhexyl) trimellitate, tri-n-octyl trimellitate, triisooctyl trimellitate, triisononyl trimellitate, tridecyl trimellitate, triisodecyl trimellitate, and the like; for example, a pyromellitic plasticizer such as tetra- (2-ethylhexyl) pyromellitic acid tetra-n-octyl pyromellitate, and the like.

Examples of the phosphoric acid plasticizer include triethyl phosphate, tributyl phosphate, tris- (2-ethylhexyl) phosphate, tris (butoxyethyl) phosphate, triphenyl phosphate, octyldiphenyl phosphate, tolyldiphenyl phosphate, tolylphenyl phosphate, tris (tolyl) phosphate, tris (xylyl) phosphate, tris (chloroethyl) phosphate, tris (chloropropyl) phosphate, tris (dichloropropyl) phosphate, and tris (isopropylphenyl) phosphate.

Examples of the polyol plasticizer include glycol plasticizers such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol di- (2-ethylbutyrate), triethylene glycol di- (2-ethylhexanoate), and industrial methyl bis (thioglycollic acid) dibutyl ester; for example, glycerol plasticizers such as monoacetin, triacetin, and tributyrin.

Examples of the epoxy plasticizer include epoxidized soybean oil, butyl epoxystearate, epoxy hexahydrophthalic acid di (2-ethylhexyl), epoxy hexahydrophthalic acid diisodecyl ester, epoxy triglyceride, epoxidized octyl oleate, and epoxidized decyl oleate.

Examples of the polyester plasticizer include adipic acid polyester, sebacic acid polyester, and phthalic acid polyester.

Examples of the carbonate plasticizer include propylene carbonate and ethylene carbonate.

In addition to the plasticizer, a partially hydrogenated terphenyl, an adhesive plasticizer, a polymerizable plasticizer such as diallyl phthalate, an acrylic monomer, or an oligomer, and the like are also included. These plasticizers may be used alone or in combination of 2 or more.

(phosphoric acid compound)

Examples of the phosphoric acid compound (C6) include phosphoric acid, pyrophosphoric acid, triphosphoric acid, acid methyl phosphate, acid ethyl phosphate, acid butyl phosphate, dibutyl phosphate, acid 2-ethylhexyl phosphate, bis (2-ethylhexyl) phosphate, acid isododecyl phosphate, acid butoxyethyl phosphate, acid oil phosphate, acid tetracosyl phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate.

(form of adhesive)

The adhesive of the present invention may be in any form of a solvent-free type or a solvent-free type, and in particular, is suitable for a case where the storage stability of a urethane prepolymer synthesized from 4,4' -MDI as a main component is easily insufficient because it does not contain an organic solvent. In the present specification, the "solvent-based" adhesive means a form used in a dry lamination method, which is a method of applying an adhesive to a substrate, heating the substrate in an oven or the like, volatilizing an organic solvent in the coating film, and bonding the film to another substrate. Either or both of the polyisocyanate composition (X) and the polyol composition (Y) contain an organic solvent capable of dissolving (diluting) the constituent components of the polyisocyanate composition (X) and the polyol composition (Y) used in the present invention.

Examples of the organic solvent 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, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and dichloroethane, dimethyl sulfoxide and dimethyl sulfonamide. The organic solvent used as a reaction medium in the production of the constituent components of the polyisocyanate composition (X) and the polyol composition (Y) may be further used as a diluent in the coating.

In the present specification, the "solvent-free type" adhesive means a form of an adhesive used in the following method, that is, the so-called solvent-free lamination method: the polyisocyanate composition (X) and the polyol composition (Y) are substantially free from esters such as ethyl acetate, butyl acetate, cellosolve acetate, ketones such as acetone, methyl ethyl ketone, isobutyl ketone, cyclohexanone, ethers such as tetrahydrofuran, dioxane, aromatic hydrocarbons such as toluene, xylene, halogenated hydrocarbons such as methylene chloride, dichloroethane, organic solvents having high solubility such as dimethyl sulfoxide and dimethyl sulfonamide, particularly ethyl acetate or methyl ethyl ketone, and are bonded to other substrates without a step of evaporating the solvents by heating in an oven or the like after the adhesive is applied to the substrates. When the organic solvent used as a reaction medium at the time of producing the constituent components of the polyisocyanate composition (X) or the polyol composition (Y) or the raw materials thereof is not completely removed and a trace amount of the organic solvent remains in the polyisocyanate composition (X) or the polyol composition (Y), it is understood that the organic solvent is substantially not contained. In addition, in the case where the polyol composition (Y) contains a low-molecular-weight alcohol, the low-molecular-weight alcohol reacts with the polyisocyanate composition (X) to become a part of the coating film, and therefore, it is not necessary to volatilize it after coating. Thus, such a form is also treated as a solvent-free adhesive, and the low molecular weight alcohol is not regarded as an organic solvent.

The adhesive of the present invention is preferably used in such a manner that the ratio [ NCO ]/[ OH ] of the number of moles of isocyanate groups [ NCO ] contained in the polyisocyanate composition (X) to the number of moles of hydroxyl groups [ OH ] contained in the polyol composition (Y) is 1.0 to 3.0. Thus, appropriate curability can be obtained independently of the ambient humidity at the time of coating.

< laminate >

The adhesive of the present invention can be suitably used for the production of laminates, particularly laminates for food packaging. Such a laminate is obtained by bonding a plurality of substrates (films or papers) using the above adhesive by a dry lamination method or a solvent-free lamination method. The film to be used is not particularly limited, and a film corresponding to the application can be appropriately selected. Examples of the food packaging film include polyolefin films such as polyethylene terephthalate (PET) films, polystyrene films, polyamide films, polyacrylonitrile films, polyethylene films (LLDPE: low-density polyethylene films, HDPE: high-density polyethylene films), polypropylene films (CPP: unstretched polypropylene films, OPP: biaxially stretched polypropylene films), polyvinyl alcohol films, and ethylene-vinyl alcohol copolymer films.

In addition, a biomass film formed of a material containing a biomass-derived component is also preferably used. For example, a sheet described in the general national institute of organic resources, the biomass film may be used as a sheet listed in a list of biomass-approved goods.

Specifically, a biomass film using biomass-derived ethylene glycol as a raw material is known as a biomass film. The biomass-derived ethylene glycol is produced from ethanol (biomass ethanol) as a raw material, and the ethanol is produced from biomass as a raw material. For example, biomass ethanol is produced into ethylene glycol via ethylene oxide by a conventionally known method, and biomass-derived ethylene glycol can be obtained by this method or the like. In addition, a commercially available biomass glycol may be used, and for example, a biomass glycol sold by India glycerols company may be suitably used.

For example, as an alternative to conventional polyethylene terephthalate films using petroleum-based materials, films containing biomass polyesters, biomass polyethylene terephthalate, and the like, in which biomass-derived ethylene glycol is used as a diol unit and fossil-fuel-derived dicarboxylic acid is used as a dicarboxylic acid unit, are known.

The dicarboxylic acid units of biomass polyesters use dicarboxylic acids of fossil fuel origin. As the dicarboxylic acid, an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, and derivatives thereof can be used without limitation.

In addition to the diol component and the dicarboxylic acid component, a copolymer component may be added as a 3 rd component selected from the group consisting of 2-functional hydroxycarboxylic acids, 3-functional or higher polyols used for forming a crosslinked structure, 3-functional or higher polycarboxylic acids and/or anhydrides thereof, and at least 1 type of polyfunctional compound among 3-functional or higher hydroxycarboxylic acids.

For example, as a substitute for a conventional polyolefin film using a petroleum-based raw material, a biomass polyolefin film such as a biomass polyethylene film or a biomass polyethylene-polypropylene film containing a polyethylene resin obtained from biomass-derived ethylene glycol as a raw material is known.

The polyethylene resin is not particularly limited except that the biomass-derived ethylene glycol is used as a part of the raw material, and examples thereof include homopolymers of ethylene, copolymers of ethylene and α -olefin (ethylene- α -olefin copolymer containing 90 mass% or more of ethylene units) and the like, and 1 kind of the above-mentioned copolymers may be used alone or 2 kinds or more may be used in combination.

The α -olefin constituting the copolymer of ethylene and α -olefin is not particularly limited, and examples thereof include α -olefins having 4 to 8 carbon atoms such as 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene. 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 resins (LLDPE) (copolymer of ethylene and 1-hexene or copolymer of ethylene and 1-octene) are preferred, and densities of 0.910 to 0.925g/cm are more preferred from the viewpoint of less possibility of damage such as open pores and breakage even if friction occurs between films ³ Linear low density polyethylene resin of (a).

As the biomass film, a biomass film using a biomass raw material distinguished by a degree of biomass plastics specified in ISO16620 or astm d6866 is also in circulation. The radioactive carbon 14C is present in the atmosphere in a proportion of 1 out of 1012, and this proportion is unchanged in the carbon dioxide in the atmosphere, and therefore, in the plant in which the carbon dioxide is immobilized by photosynthesis. Thus, the carbon of the plant-derived resin contains radioactive carbon 14C. In contrast, the radioactive carbon 14C is substantially not contained in the carbon of the fossil fuel-derived resin. Thus, the concentration of radioactive carbon 14C in the resin was measured by an accelerator mass spectrometer, and the content of the plant-derived resin in the resin, that is, the degree of biomass molding, was determined.

Examples of the plant-derived low-density polyethylene which is a biomass plastic having a biomass plastics content of 80% or more, preferably 90% or more, specified in ISO16620 or ASTM D6866 include trade names "SBC818", "SPB608", "SBF0323HC", "STN7006", "SEB853", and "SPB681" manufactured by Braskem corporation, and films using these as raw materials can be suitably used.

Films and sheets containing starch and polylactic acid as biomass materials are also known. They can be appropriately selected and used according to the purpose.

The biomass film may be a laminate of a plurality of biomass films, or may be a laminate of a conventional petroleum-based film and a biomass film. These biomass films may be unstretched films or stretched films, and the production method thereof is not limited.

The film may be a film subjected to a stretching treatment. As a stretching treatment method, a sheet-like resin is usually melt-extruded by an extrusion film-forming method or the like, and then simultaneously biaxially stretched or successively biaxially stretched. In the case of sequential biaxial stretching, it is common to perform longitudinal stretching treatment and then transverse stretching. Specifically, a method of combining longitudinal stretching using a speed difference between rolls and transverse stretching using a tenter is commonly used.

The film surface may be subjected to various surface treatments such as flame treatment and corona discharge treatment as needed to form an adhesive layer free from defects such as film breakage and shrinkage cavity.

Alternatively, a film in which vapor deposition layers of metal such as aluminum, metal oxide such as silica, and alumina are laminated, or a barrier film containing a gas barrier layer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and vinylidene chloride may be used. By using such a film, a laminate having barrier properties against water vapor, oxygen, alcohol, inert gas, volatile organic compounds (flavor) and the like can be produced.

As the paper, a known paper base material can be used without particular limitation. Specifically, the paper-making natural fiber such as wood pulp is used and manufactured by a known paper machine, and the paper-making sheet is not particularly limited. Examples of the natural fibers for paper production include wood pulp such as conifer pulp and hardwood pulp, non-wood pulp such as abaca pulp, sisal pulp and flax pulp, and pulp obtained by chemically modifying these pulps. As the kind of pulp, chemical pulp, grinding pulp, chemical grinding pulp, thermomechanical pulp, and the like based on sulfate hydrolysis, acid/neutral/alkali sulfite hydrolysis, sodium salt hydrolysis, and the like can be used. In addition, various commercially available high quality papers, coated papers, lining papers, impregnated papers, cardboard papers, paperboard, and the like may be used.

More specific preferable configurations of the laminate exhibiting the characteristics of the present invention include, for example, PET film/adhesive layer '/aluminum foil/adhesive layer/CPP film, PET film/adhesive layer '/Ny film/adhesive layer "/aluminum foil/adhesive layer/CPP film, PET film/adhesive layer '/aluminum foil/adhesive layer/Ny film/adhesive layer/CPP film, and the like. These laminates are used for packaging materials which often require a boiling treatment or a steaming treatment. Since PAA is easily transferred from the adhesive layer to the content during the boiling treatment or the steaming treatment, the adhesive used for the laminate to be subjected to such treatment is required to be reduced in PAA at a high rate, and the adhesive of the present invention is an adhesive which responds to such a requirement. The adhesive of the present invention is preferably used in an adhesive layer disposed between an aluminum foil and a sealing film. The adhesive layer', adhesive layer "may be formed using the adhesive of the present invention, or may not be formed.

Examples of other preferable configurations include an OPP film/adhesive layer/CPP film, an OPP film/adhesive layer/LLDPE film, an OPP/adhesive layer/aluminum vapor deposited CPP film, a PET film/adhesive layer/LLDPE film, a PET film/adhesive layer/aluminum vapor deposited CPP film, an Ny film/adhesive layer/LLDPE film, an OPP film/adhesive layer '/aluminum vapor deposited PET film/adhesive layer/LLDPE film, a PET film/adhesive layer '/aluminum vapor deposited PET film/adhesive layer/LLDPE film, a Ny film/adhesive layer '/aluminum vapor deposited PET film/adhesive layer/LLDPE film, and the like, but are not limited thereto. In the above-described configuration, the adhesive layer is a cured coating film of the adhesive of the present invention. The adhesive layer' may be a cured coating film of the adhesive of the present invention, or may be a cured coating film of another adhesive.

The laminate may be provided with a printed layer between the adhesive layer and the substrate (typically, the substrate that is the outermost layer with respect to the content). The printing layer is formed by various printing inks such as gravure ink, flexo ink, offset ink, stencil ink, and inkjet ink, and by a conventional printing method for printing on a film.

When the adhesive is a solvent type, the adhesive of the present invention is applied to one substrate by using a roll such as a gravure roll, and the organic solvent is volatilized by heating in an oven or the like, and then the other substrate is bonded to obtain the laminate of the present invention. Preferably, the curing treatment is performed after lamination. The curing temperature is preferably room temperature to 80 ℃, and the curing time is preferably 12 to 240 hours.

When the adhesive is solvent-free, the adhesive of the present invention is applied to one substrate by a roll such as a coating roll and then the other substrate is immediately bonded to the substrate after the adhesive is preheated to about 40 to 100 ℃. Preferably, the curing treatment is performed after lamination. The curing temperature is preferably from room temperature to 70℃and the curing time is preferably from 6 to 240 hours.

The amount of the adhesive to be applied is appropriately adjusted. In the case of the solvent type adhesive, for example, the solid content is adjusted to 1g/m ² Above and 10g/m ² Hereinafter, it is preferably adjusted to 2g/m ² Above and 5g/m ² The following is given. In the case of the solvent-free adhesive, for example, the application amount of the adhesive is 1g/m ² Above mentionedAnd 5g/m ² Hereinafter, it is preferably 1g/m ² Above and 3g/m ² The following is given.

The laminate may be obtained by bonding 2 substrates with the adhesive of the present invention, or may contain other substrates as required. As a method for laminating the other base material, lamination may be performed by a known method, for example, a dry lamination method, a solvent-free lamination method, a thermal lamination method, a heat sealing method, an extrusion lamination method, or the like. The adhesive used in this case may or may not be the adhesive described above. As the other substrate, the same substrate as the above substrate can be used.

< packaging Material >

The laminate is suitably used as a packaging material, particularly a packaging material for food packaging. The packaging material is formed by forming the laminate into a bag shape and heat-sealing the bag shape. As a packaging material, there are various types of packaging materials, such as three-side sealing bags, four-side sealing bags, gusset packaging bags, pillow packaging bags, roof-type bottomed containers, cola bags, brick-type (japanese drive), hose containers, paper cups, and lidstock. In addition, the packaging material can be appropriately designed with easy-to-open processing and resealability means.

The packaging material of the present invention is suitably used mainly for food use, and may be suitably used as a packaging material for filling detergents and medicines. Specific examples of the use of the detergent or the pharmaceutical agent include a liquid detergent for washing, a liquid detergent for kitchen, a liquid detergent for bath, a liquid soap for bath, a liquid shampoo, a liquid conditioner, and a pharmaceutical tablet. In addition, the packaging material can also be used for packaging the 2 times of the container.

Examples

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

< preparation of polyisocyanate composition (X)

Synthesis example 1

[ Synthesis of polyester polyol A ]

To a polyester reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet tube, a schneider tube, and a condenser, 122 parts of ethylene glycol, 267 parts of neopentyl glycol, and 6 parts of trimethylolpropane were added, and the mixture was heated to 80℃while stirring under a nitrogen flow. Then, 516 parts of adipic acid and 90 parts of isophthalic acid were added to the reaction vessel while stirring, and the esterification reaction was performed by heating to 240℃while gradually raising the temperature of the upper part of the Snoder tube to a temperature of more than 100 ℃. The reaction vessel was gradually depressurized when the acid value became 5mgKOH/g or less, and reacted at 240℃under 1mmHg for 2 hours to obtain a polyester polyol A having an acid value of 0.8mgKOH/g, a molecular weight of about 1650, a hydroxyl value of about 68mgKOH/g and a water content of 0.016 mass%.

[ preparation of polyisocyanate composition (X-1) ]

48.6 parts of an isocyanate composition (i-1) having a content of 0.1% by mass of 2, 2-diphenylmethane diisocyanate, a content of 0.8% by mass of 2, 4-diphenylmethane diisocyanate, a content of 80.8% by mass of 4,4' -diphenylmethane diisocyanate and a content of 18.3% by mass of Sumidur N3300 (manufactured by Sumika Covestro Urethane Co.) were charged into a reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet pipe and a condenser, and heated to 60℃under nitrogen flow while stirring. To this was added dropwise a polyol composition (ii-1) containing 26.4 parts of polyester polyol A, 11.9 parts of polypropylene glycol having a number average molecular weight of 2000 (hereinafter referred to as PPG 2000), 0.00264 parts of phosphoric acid and a water content of 0.042% by mass in several portions, followed by heating and holding at an internal temperature of 80℃for 3 hours, and a urethanization reaction was carried out. Then, after heating to 100℃for 1 hour, the reaction was carried out for 3 hours to obtain a urethane prepolymer.

The urethane prepolymer in the reaction vessel was cooled to 50℃and 13.1 parts of carbodiimide-modified diphenylmethane diisocyanate (product name: lupranate MM103, manufactured by BASF corporation) was added thereto and stirred until uniform, to obtain polyisocyanate composition (X-1) of Synthesis example 1 having 16.7% of NCO, 0.3% by mass of urea derivative, 0.6% by mass of biuret derivative and a viscosity of 2380mPa.s at 25 ℃.

Synthesis examples 2 to 5

The polyisocyanate compositions (X-2) to (X-5) of Synthesis examples 2 to 5 were obtained in the same manner as in Synthesis example 1 except that the amounts of the isocyanate composition (i), the polyol composition (ii) and the isocyanate compound to be added to the urethane prepolymer used were changed as shown in Table 1.

Synthesis example 6

The polyisocyanate composition (X-6) of Synthesis example 6 was synthesized in the same manner as in Synthesis example 1 except that the isocyanate composition (i), the polyol composition (ii) and the amount of the isocyanate compound added to the urethane prepolymer used were changed as shown in Table 2 and the holding time at 100℃of the urethane prepolymer was changed to 8 hours.

Synthesis example 7

The polyisocyanate composition (X-7) of Synthesis example 7 was prepared in the same manner as in Synthesis example 1 except that the amounts of the isocyanate compound(s) to be added to the isocyanate composition (i), the polyol composition (ii) and the urethane prepolymer to be used were changed as shown in Table 2. The urea form used in the isocyanate composition (i) is a urea form of 4,4'-MDI and hydrated 4,4' -MDI, and the biuret form is a biuret form of 4,4'-MDI and hydrated 4,4' -MDI.

Synthesis example 8

A polyisocyanate composition (X-8) of Synthesis example 8 was prepared in the same manner as in Synthesis example 1 except that the amounts of the isocyanate compound(s) to be added to the urethane prepolymer(s) and the polyol composition (ii) to be used were changed as shown in Table 2. The urea synthesized and added to the urethane prepolymer was a urea of 4,4'-MDI and a water-formed 4,4' -MDI, and the biuret was a biuret of 4,4'-MDI and a water-formed 4,4' -MDI.

Synthesis example 9

A polyisocyanate composition (X-9) of Synthesis example 9 was prepared in the same manner as in Synthesis example 1 except that carbodiimide-modified diphenylmethane diisocyanate was not added.

Synthesis example 10

[ Synthesis of polyester polyol B ]

To a polyester reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet tube, a schneider tube, and a condenser, 503 parts of diethylene glycol was added, and the mixture was heated to 80 ℃ while stirring under a nitrogen flow. Then, 595 parts of adipic acid and 0.1 part of dibutyltin dilaurate were added to the reaction vessel with stirring, and the esterification reaction was performed by heating to 240℃while gradually raising the temperature of the upper part of the Snider tube to a temperature of more than 100 ℃. The reaction vessel was gradually depressurized when the acid value became 5mgKOH/g or less, and reacted at 240℃under 1mmHg for 2 hours to give a polyester polyol B having an acid value of 0.8mgKOH/g, a molecular weight of about 1520, a hydroxyl value of about 74mgKOH/g and a water content of 0.018 mass%.

[ preparation of polyisocyanate composition (X-10) ]

The polyisocyanate composition (X-10) of Synthesis example 10 was synthesized in the same manner as in Synthesis example 1 except that the isocyanate composition (i), the polyol composition (ii) and the amount of the isocyanate compound added to the urethane prepolymer used were changed as shown in Table 3 and the holding time at 100℃of the urethane prepolymer was changed to 8 hours. The PPG1000 in the table is a polypropylene glycol having a number average molecular weight of 1000.

Synthesis example 11

The polyisocyanate composition (X-11) of Synthesis example 11 was synthesized in the same manner as in Synthesis example 1 except that the amounts of the isocyanate compound(s) to be added to the urethane prepolymer(s) and the polyol composition (i) and the isocyanate composition (i) to be used were changed as shown in Table 3. The PPG400 in the table is a polypropylene glycol having a number average molecular weight of 400.

Synthesis example 12

48.6 parts of an isocyanate composition (i-12) having a content of 0.1% by mass of 2, 2-diphenylmethane diisocyanate, a content of 0.8% by mass of 2, 4-diphenylmethane diisocyanate, a content of 80.8% by mass of 4,4' -diphenylmethane diisocyanate and a content of 18.3% by mass of Sumidur N3300 (manufactured by Sumika Covestro Urethane Co.) were charged into a reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet pipe and a condenser, and heated to 60℃under nitrogen flow while stirring. To this was dropwise added a polyol composition (ii-9) containing 26.4 parts of polyester polyol A, 11.9 parts of PPG2000, 0.00264 parts of phosphoric acid and a water content of 0.042 mass% in several portions, followed by heating and holding at an internal temperature of 80℃for 3 hours, and urethanization reaction was carried out to obtain a urethane prepolymer having a urea derivative content of 0.6 mass% and a biuret derivative content of 0.1 mass%.

The urethane prepolymer in the reaction vessel was cooled to 50℃and 13.1 parts of carbodiimide-modified diphenylmethane diisocyanate (product name: lupranate MM103, manufactured by BASF corporation) was added thereto and stirred until uniform, to obtain a polyisocyanate composition (X-12) of Synthesis example 9 having an NCO% of 16.7%.

Synthesis example 13

48.6 parts of an isocyanate composition (i-13) having a content of 1.0% by mass of 2, 2-diphenylmethane diisocyanate, a content of 35.7% by mass of 2, 4-diphenylmethane diisocyanate, a content of 45.0% by mass of 4,4' -diphenylmethane diisocyanate and a content of 18.3% by mass of Sumidur N3300 (manufactured by Sumika Covestro Urethane Co.) were charged into a reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet pipe and a condenser, and heated to 60℃under nitrogen flow while stirring. To this was dropwise added a polyol composition (ii-13) containing 26.4 parts of polyester polyol A, 11.9 parts of PPG2000, 0.00264 parts of phosphoric acid and a water content of 0.042 mass% in several portions, followed by heating and holding at an internal temperature of 80℃for 3 hours, and urethanization reaction was carried out to obtain a urethane prepolymer having a urea derivative content of 0.6 mass% and a biuret derivative content of 0.1 mass%.

The urethane prepolymer in the reaction vessel was cooled to 50℃and 13.1 parts of carbodiimide-modified diphenylmethane diisocyanate (product name: lupranate MM103, manufactured by BASF corporation) was added thereto and stirred until uniform, to obtain a polyisocyanate composition (X-13) of Synthesis example 13 having an NCO% of 16.7%.

The urea derivative and biuret derivative contents of the polyisocyanate composition (X) were measured by a liquid chromatograph quadrupole time-of-flight mass spectrometer (LC-QTOF-MS) under the following conditions.

Measurement device: ACQUITY UPLC H-Class, syntapt G2-S MS manufactured by Waters

Chromatographic column: ACQUITY UPLC HSS-T3C 18 Column manufactured by Waters

Flow rate: 0.3mL/min

Mobile phase a: acetonitrile/THF (80/20 weight ratio)

Mobile phase B:10mM ammonium acetate aqueous solution

Mass measurement range (m/z): 50-1800

TABLE 1

TABLE 2

TABLE 3

< preparation of polyol composition (Y) >

[ Synthesis of polyester polyol ]

To a flask equipped with a stirrer, a thermometer, a nitrogen inlet pipe, a rectifying pipe, a water separator and the like, 36.7 parts of diethylene glycol, 12.2 parts of 2-methyl-1, 3-propanediol and 5.5 parts of trimethylolpropane were added, and the mixture was heated to 80℃while stirring under a nitrogen flow. Then, 50.4 parts of adipic acid was added to the reaction vessel while stirring, and the internal temperature was kept at 220℃so that the upper temperature of the rectifying tube was not higher than 100℃and the esterification reaction was carried out. The inside of the reaction vessel was gradually depressurized when the acid value became 5.0mgKOH/g or less and reacted at 40Torr or less to obtain a polyester polyol having hydroxyl groups at both terminals and having an acid value of 1.0mgKOH/g and a hydroxyl value of 200 mgKOH/g. This was used as the polyol composition (Y).

< preparation of adhesive >

Solvent-free adhesives of examples 1 to 11 and comparative examples 1 and 2 were prepared by blending the polyisocyanate composition (X) and the polyol composition (Y) heated to 40℃in accordance with tables 6 to 8.

< evaluation >

(storage stability of polyisocyanate composition (X))

After the 15 mL-capacity glass bottle was filled with the polyisocyanate composition (X) and stored at normal temperature for a certain period, the appearance turbidity was evaluated visually on 3 levels according to the following criteria, and the results are summarized in tables 4 and 5.

And (3) the following materials: no turbidity for more than 2 months

O: turbidity occurs in 1-2 months

X: turbidity occurs within 1 month

(PAA elution amount)

The PET film was coated with the 2-liquid adhesive compounded in the combination of examples or comparative examples so that the coating amount was 3.0g/m in terms of solid content ² The coated surface of the film was bonded to a CPP film by a laminator to produce a laminated film. The laminated film was stored in a constant temperature bath at 40℃for 3 days. The laminate film was cut out at 120mm×220mm, the CPP film was folded so as to be inside, and heat-sealed at 1atm and 190℃for 1 second in 3 directions with a width of 10mm, to prepare a content contact 2dm ² Is a bag of (a). The bag filled with 3% acetic acid solution as the content was sterilized by steaming at 121℃for 0.5hr, and then the PAA was measured by LC/MS/MS. The evaluation was set as follows.

O: less than 10ppb

X: 10ppb or more

(lamination Strength)

In using printing ink UNIVURE NT (Japanese: to (n.y) NT) (DIC) gravure-printed pattern, a 2-liquid adhesive prepared by combining the examples or comparative examples was applied so that the applied amount was 3.0g/m in terms of solid content ² . Thereafter, the coated surface of the film was bonded to an LLDPE film by a laminator to produce a laminated film. The laminate was stored in a constant temperature bath at 40℃for 3 days to prepare a laminate for a laminate strength test. Test pieces were cut out from the laminate film at a width of 15mm, and the adhesive strength (N/15 mm) was measured at a peeling speed of 300mm/min by 180 degree peeling using a tensile tester. The evaluation was set as follows.

O: 5N/15mm or more

X: less than 5N/15mm

TABLE 4

X-1

X-2

X-3

X-4

X-5

X-6

X-7

Storage stability

◎

◎

○

○

◎

◎

◎

TABLE 5

X-8

X-9

X-10

X-11

X-12

X-13

Storage stability

◎

◎

◎

◎

×

◎

TABLE 6

	Example 1	Example 2	Example 3	Example 4	Example 5
						Polyisocyanate composition (X-1)	100
Polyisocyanate composition (X-2)		100
						Polyisocyanate composition (X-3)			100
Polyisocyanate composition (X-4)				100
						Polyisocyanate composition (X-5)					100
Polyol composition (Y)	70	70	70	70	70
						PAA elution amount	○	○	○	○	○
Lamination strength	○	○	○	○	○

TABLE 7

	Example 6	Example 7	Example 8	Example 9
					Polyisocyanate composition (X-6)	100
Polyisocyanate composition (X-7)		100
					Polyisocyanate composition (X-8)			100
Polyisocyanate composition (X-9)				100
					Polyol composition (Y)	70	70	70	70
PAA elution amount	○	○	○	○
					Lamination strength	○	○	○	○

TABLE 8

	Example 10	Example 11	Comparative example 1	Comparative example 2
					Polyisocyanate composition (X-10)	100
Polyisocyanate composition (X-11)		100
					Polyisocyanate composition (X-12)			100
Polyisocyanate composition (X-13)				100
					Polyol composition (Y)	70	50	70	70
PAA elution amount	○	○	○	×
					Lamination strength	○	○	○	○

Claims (5)

1. A2-liquid curable adhesive comprising an isocyanate composition X and a polyol composition Y comprising a polyol compound,

the isocyanate composition X comprises a urethane prepolymer which is the reaction product of an isocyanate composition i in which the content of 4,4' -diphenylmethane diisocyanate is 75.0% by mass or more, the content of 2,2' -diphenylmethane diisocyanate is 0.5% by mass or less, the content of 2,4' -diphenylmethane diisocyanate is 5.0% by mass or less, a biuret derivative of 4,4' -diphenylmethane diisocyanate and a urea derivative of 4,4' -diphenylmethane diisocyanate,

in the isocyanate composition X, the content of the biuret derivative is 0.4 mass% or more and 20.0 mass% or less, and the content of the biuret derivative is 1.0 times or more the content of the urea derivative.

2. The 2-liquid curable adhesive according to claim 1, wherein,

the polyol composition ii comprises at least one of a polyether polyol or a polyester polyol.

3. The 2-liquid curable adhesive according to claim 1 or 2, wherein,

the polyol compound includes at least one of a polyether polyol or a polyester polyol.

4. A laminate comprising a first substrate, a second substrate, and an adhesive layer for bonding the first substrate to the second substrate,

the adhesive layer is a cured coating film of the 2-liquid curable adhesive according to any one of claims 1 to 3.

5. A packaging material comprising the laminate of claim 4.