JP7409570B2 - Method for manufacturing urethane prepolymer - Google Patents

Description

The present invention relates to a method for producing a urethane prepolymer suitable for a two-part curable adhesive.

Laminated bodies used for various packaging materials, labels, etc. are given design properties, functionality, preservability, convenience, transportation resistance, etc. by laminating a wide variety of base materials such as plastic films, metal foils, and papers. be done. A packaging material formed by forming the laminate into a bag shape is used as a packaging material for foods, medicines, detergents, and the like.

Conventionally, laminates used for packaging materials are made by coating a base material with an adhesive dissolved in a volatile organic solvent (sometimes referred to as a solvent-based laminating adhesive), and then passing through an oven to remove organic laminates. The mainstream was to obtain products using a dry lamination method in which solvents are evaporated and another base material is laminated, but in recent years, from the perspective of reducing environmental impact and improving the work environment, reactive products that do not contain volatile organic solvents have been developed. Demand for two-component type laminating adhesives (hereinafter referred to as solvent-free adhesives) is also increasing (Patent Document 1).

Japanese Patent Application Publication No. 2014-159548

When producing a laminate for food packaging using such a two-component urethane adhesive, the isocyanate monomer remaining in the adhesive layer may pose a problem. If the aromatic isocyanate monomer remains in the adhesive layer, it reacts with surrounding water to form a primary aromatic amine (PAA). The generated PAA may migrate through the film and elute into the contents (food). There are concerns that PAA may be harmful to the human body, and various regulations have been established, such as the European Commission setting detection limits for plastic materials and products for food contact.

PAA generated by the reaction between aromatic isocyanate and water further reacts with water, so even if aromatic isocyanate remains in the adhesive layer, the concentration of PAA gradually decreases and eventually falls below the detection limit. When producing a laminate for food packaging, it is preferable that the PAA concentration decreases at a faster rate. From this point of view, it is preferable to use 4,4'-diphenylmethane diisocyanate, which has relatively excellent reactivity, as the raw material for the isocyanate component of the adhesive. However, 4,4'-diphenylmethane diisocyanate has high crystallinity, and urethane prepolymers with a high content of 4,4'-diphenylmethane diisocyanate have poor storage stability, such as crystallization or turbidity during storage even at room temperature. Inferior.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a urethane prepolymer for a two-component curable adhesive that has a high PAA reduction rate and excellent storage stability.

In the present invention, 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, and 4,4'-phenyl An isocyanate composition (i) having a content of methane diisocyanate of 75.0% by mass or more and a polyol composition (ii) are added to the isocyanate composition contained in the isocyanate groups with respect to the active hydrogen groups contained in the polyol composition. A first step of obtaining the urethane prepolymer (I) by reacting at a temperature of 65°C or higher and 85°C or lower under conditions where the group is in excess, and a heat treatment of the urethane prepolymer (I) at a temperature of 95°C or higher and 110°C or lower. A second step of obtaining urethane prepolymer (II).

According to the adhesive of the present invention, it is possible to provide a urethane prepolymer for a two-component curable adhesive that has a fast PAA reduction rate and excellent storage stability.

<Manufacturing method>
(Isocyanate composition (i))
The isocyanate composition (i) used in the production method of the present invention is 4,4'-diphenylmethane diisocyanate (hereinafter also referred to as 4,4'-MDI), which is free from concerns regarding PAA even if it remains as a monomer, at a concentration of 75.0%. Contains more than % by mass. Further, the content of 2,2'-diphenylmethane diisocyanate (hereinafter referred to as 2,2'-MDI) is 0.5% by mass or less, and the content of 2,4'-diphenylmethane diisocyanate (2,4'-MDI) is 5% by mass or less. It is 0% by mass. 2,2'-MDI and 2,4'-MDI have lower reactivity than 4,4'-MDI, and the rate of decrease in PAA is relatively slow, so it is preferable to have a low content of 4, It may be mixed in as an impurity when 4'-MDI is synthesized and isolated. If the content is at the above level, it will not have a large effect on the rate of decrease of PAA.

The isocyanate composition (i) used in the production method of the present invention may contain isocyanate compounds other than 4,4'-MDI, 2,2'-MDI, and 2,4'-MDI. Isocyanate compounds used in combination with these isocyanates may be non-aromatic isocyanate compounds such as araliphatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and derivatives thereof (buret, nurate, adduct, allophanate). preferable.

Aroaliphatic diisocyanate means an aliphatic isocyanate having one or more aromatic rings in the molecule, and includes m- or p-xylylene diisocyanate (also known as XDI), α, α, α', α'-tetra Examples include, but are not limited to, methyl xylylene diisocyanate (also known as TMXDI).

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

Examples of alicyclic diisocyanates include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate (also known as IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, and 1,4-cyclohexane. Examples include diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanatomethyl)cyclohexane, etc. but not limited to.

When the isocyanate composition (i) contains a non-aromatic isocyanate, from the viewpoint of reaction rate etc. when used as a two-component curing adhesive described below, the blending amount is 20% by mass or less of the total amount of the isocyanate composition (i). It is preferable that there be.

(Polyol composition (ii))
The polyol composition (ii) used in the production method of the present invention contains a polyol compound. The polyol compound is not particularly limited, and any compound that can be commonly used as a urethane prepolymer can be used as appropriate. For example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5- Pentanediol, 1,6-hexanediol, neopentyl glycol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4- Glycols such as cyclohexanediol and 1,4-cyclohexanedimethanol;

trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol;
Bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F; dimer diol;
A polyether polyol obtained by addition-polymerizing an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, or cyclohexylene in the presence of a polymerization initiator such as the glycol, trifunctional or tetrafunctional aliphatic alcohol, etc. ;
A polyether urethane polyol obtained by further increasing the molecular weight of a polyether polyol with an isocyanate compound;

Polyesters obtained by ring-opening polymerization reaction of cyclic ester compounds such as propiolactone, butyrolactone, ε-caprolactone, σ-valerolactone, β-methyl-σ-valerolactone, and the aforementioned glycols, glycerin, trimethylolpropane, pentaerythritol, etc. A polyester polyol (1) which is a reaction product with a polyhydric alcohol;
Polyester polyol (2) obtained by reacting a bifunctional polyol such as the glycol, dimer diol, or bisphenol with a polyhydric carboxylic acid:
Polyester polyol (3) obtained by reacting a trifunctional or tetrafunctional aliphatic alcohol with a polycarboxylic acid;
A polyester polyol (4) obtained by reacting a bifunctional polyol, the trifunctional or tetrafunctional aliphatic alcohol, and a polyhydric carboxylic acid;
Polyester polyol (5), which is a polymer of hydroxyl acids such as dimethylolpropionic acid and castor oil fatty acid;

A polyester polyether polyurethane polyol obtained by reacting at least one of polyester polyols (1) to (5) with a polyether polyol and an isocyanate compound;
Polyester polyurethane polyol obtained by increasing the molecular weight of polyester polyols (1) to (5) with an isocyanate compound;
Examples include castor oil, dehydrated castor oil, hydrogenated castor oil which is a hydrogenated product of castor oil, castor oil-based polyols such as castor oil adducts with 5 to 50 moles of alkylene oxide, and mixtures thereof.

Polyvalent carboxylic acids used in the synthesis of polyester polyols (2) to (4) include orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic 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 ) Aromatic polybasic acids such as ethane-p,p'-dicarboxylic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic dianhydride, 5-sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, tetrabromophthalic anhydride;
Methyl esters of aromatic polybasic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalene dicarboxylate;

Aliphatic polybasic acids such as malonic acid, succinic acid, succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid;
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, diethyl maleate, etc. Alkyl ester of;

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, hemic anhydride, het acid anhydride, etc. group polybasic acids; etc., and can be used alone or in combination of two or more.

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

Preferably, the polyol compound contains at least one of polyether polyols and polyester polyols.

The number average molecular weight of the polyol compound is not particularly limited, but is preferably 300 or more and 4000 or less, as an example. Note that the number average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) under the following conditions.

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

The polyol composition (ii) used in the production of the present invention preferably has a water content of 0.01% by mass or more and 0.5% by mass or less. Thereby, even when synthesized using 4,4'-MDI as a main component, it is possible to obtain a urethane prepolymer that is free from crystallization and cloudiness and has excellent storage stability. If the water content of the polyol composition is low, water may be added. If the polyol has a high water content, it may be heated to 80 to 100°C and dehydrated under reduced pressure.

It is also preferable that the polyol composition (ii) used in the production of the present invention contains a primary or secondary monoamine compound. Thereby, even when synthesized using 4,4'-MDI as a main component, it is possible to obtain a urethane prepolymer that is free from crystallization and cloudiness and has excellent storage stability.

Primary monoamine compounds include methylamine, ethylamine, propylamine, isopropylamine, butylamine, amylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine (laurylamine), Aliphatic unsaturated primary amines such as dodecylamine, tetradecylamine (myristylamine), pentadecylamine, cetylamine, stearylamine, oleylamine, cocoalkylamine, tallow alkylamine, hardened tallow alkylamine, allylamine, aniline, benzylamine etc.

Examples of secondary monoamine compounds include aliphatic unsaturated secondary amines such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diamylamine, diallylamine, methylaniline, ethylaniline, dibenzylamine, diphenylamine, dicocoalkyl Examples include amine, dihardened beef tallow alkylamine, distearylamine, and the like.

From the viewpoint of the balance between crystallization and cloudiness control of the urethane prepolymer and reactivity when used as an adhesive, which will be described later, the amount of the monoamine compound blended should be 40% by mass or less of the total amount of polyol composition (ii). is preferred.

(First step)
In the first step of the present invention, the isocyanate composition (i) and the polyol composition (ii) are mixed in such a way that the isocyanate composition (i) contains the isocyanate group (i) with respect to the active hydrogen group contained in the polyol composition (ii). Urethane prepolymer (I) is obtained by reacting at 65° C. or higher and 85° C. or lower under conditions where the group is present in excess. The equivalent ratio of isocyanate groups to active hydrogen groups [NCO]/[active hydrogen groups] can be adjusted as appropriate depending on the purpose, and is, for example, 2.0 or more and 20.0 or less.

Moreover, in the first step, the isocyanate composition (i) and the polyol composition (ii) may be reacted at once. Alternatively, the polyol composition (ii) may be added to the isocyanate composition (i) in several portions. After a part of the isocyanate composition (i) and the polyol composition (ii) are reacted at an equivalent ratio of isocyanate groups to active hydrogen groups of 1 or less to obtain a polyurethane polyol having active hydrogen groups at the terminals, the remaining Urethane prepolymer (I) may be obtained by adding isocyanate composition (i).

The first step is carried out until most of the active hydrogen groups are subjected to reaction. Whether or not most of the active hydrogen groups have been subjected to the reaction is calculated from the molar ratio of the isocyanate groups contained in the isocyanate composition (i) subjected to the reaction and the active hydrogen groups contained in the polyol composition (ii). This is determined based on the calculated NCO% of the urethane prepolymer (I) when all active hydrogen groups have reacted, and the actually measured NCO%. The first step is ended when the actual value of NCO% is less than the calculated value and the difference from the actual value 2 hours ago is 0.05% or less.

In the first step, known urethanization catalysts such as organotin compounds, organic carboxylic acid tin salts, lead carboxylates, bismuth carboxylates, titanium compounds, zirconium compounds, etc. can be used. The urethanization catalysts may be used alone or in combination of two or more. The amount of the urethanization catalyst used should just be an amount that can sufficiently promote the reaction between the polyisocyanate composition (i) and the polyol composition (ii). It is 0.001% by mass or more and 0.1% by mass or less based on the total amount of ii).

The first step may be carried out under solvent-free conditions, or may be carried out in an organic solvent that does not have reactivity with the isocyanate composition (i). Such organic solvents include aliphatic hydrocarbon solvents such as hexane, heptane, and octane; alicyclic hydrocarbon solvents such as cyclohexane and methylcyclohexane; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. ; Ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, methyl lactate, and ethyl lactate; Aromatic solvents such as toluene, xylene, diethylbenzene, mesitylene, anisole, benzyl alcohol, phenyl glycol, and chlorobenzene; ethylene glycol Glycol solvents such as monoethyl ether acetate, 3-methyl-3-methoxybutyl acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether; Ether solvents such as diethyl ether, tetrahydrofuran, dioxane; dichloromethane, 1,2-dichloroethane , halogenated hydrocarbon solvents such as chloroform; pyrrolidone solvents such as N-methyl-2-pyrrolidone; amide solvents such as N,N-dimethylacetamide and N,N-dimethylformamide; sulfoxide solvents such as dimethylsulfoxide ; Lactone solvents such as γ-butyrolactone; Amine solvents such as morpholine; and mixtures thereof. These solvents may be used alone or in combination of two or more.

(Second process)
In the second step, the urethane prepolymer (I) obtained in the first step is heat-treated while stirring while maintaining the temperature at 95° C. or higher and 110° C. There is no problem as long as it temporarily exceeds 110°C, but if the temperature in the second step is less than 95°C or exceeds 110°C, the effect of suppressing crystallization and clouding of the urethane prepolymer becomes weak. More preferably, the second step is carried out at a temperature of 95°C or higher and 105°C or lower. The second step can be performed in the same reaction vessel following the first step, and there is no need for purification or the like between the first and second steps. The product obtained through the second step is referred to as urethane prepolymer (II).

The indicator for terminating the second step is viscosity or NCO%. Although performing the second step even for a short time can be expected to have the effect of suppressing crystallization and cloudiness of the urethane prepolymer, it is more reliable to obtain a urethane prepolymer with excellent long-term storage stability. It is preferable to carry out the second step until the viscosity of the polymer (II) becomes 1.1 times or more that of the urethane prepolymer (I), and it is preferable to carry out the second step until the viscosity of the polymer (II) becomes 1.15 times or more. More preferred. The viscosity of the urethane prepolymer (II) is lower than that of the urethane prepolymer (II) from the viewpoint of the effect of suppressing crystallization and clouding of the urethane prepolymer reaching its peak, and also from the viewpoint of the balance with the coating properties when used as an adhesive, which will be described later. It is preferable to complete the second step before the viscosity exceeds 15.0 times the viscosity of I), and it is more preferable to complete the second step before the viscosity exceeds 10 times. The viscosity of the urethane prepolymers (I) and (II) is a value measured using a rotational viscometer at a cone/plate size of 1° x 50 mm in diameter, a shear rate of 100 sec ^-1 , and a temperature of 25° C.±1° C.

Alternatively, using NCO% as an index, the second step is continued until the measured value of NCO% of the urethane prepolymer (II) becomes 99% or less of the measured value of NCO% of the urethane prepolymer (I). Good too. The actual value of NCO% of urethane prepolymer (II) is It is preferable to complete the second step before the measured value of urethane prepolymer (I) falls below 80%.

(Third step)
The urethane prepolymer (II) obtained through the second step may be used as it is, or may be further added with an isocyanate compound to adjust the viscosity. This step is referred to as the third step. Examples of the isocyanate compound used in the third step include non-aromatic isocyanates and derivatives thereof, urethane prepolymers obtained from non-aromatic isocyanates and polyols, carbodiimide-modified diphenylmethane diisocyanate, allophanate-modified diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, etc. .

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

Carbodiimide-modified diphenylmethane diisocyanate, allophanate-modified diphenylmethane diisocyanate, and polymeric diphenylmethane diisocyanate usually contain monomeric diphenylmethane diisocyanate. In the present invention, a material having a 2,2'-MDI content of 2.0% by mass or less and a 2,4'-MDI content of 5.0% by mass or less is used.

<Adhesive>
The urethane prepolymer obtained by the production method of the present invention has a fast PAA reduction rate and does not have problems with crystallization or clouding over time, so it can be suitably used as an isocyanate component of a two-component curable adhesive. An example of a two-component curing adhesive using a urethane prepolymer obtained by the production method of the present invention will be described below. The two-part curable adhesive includes a polyol composition (X) and a polyisocyanate composition (Y).

(Polyol composition (X))
The polyol composition (X) contains a polyol compound having a plurality of hydroxyl groups. As the polyol compound, the same ones as those exemplified as the polyol compound that can be used in the polyol composition (ii) can be used. It is preferable that at least one of a polyester polyol, a polyether polyol, and a castor oil polyol is included.

When the adhesive of the present invention is used as a solvent-free adhesive, the viscosity of the polyol composition (X) is adjusted to a range suitable for the non-solvent laminating method. As an example, the viscosity at 40° C. is adjusted to be in the range of 100 to 5000 mPas, more preferably 100 to 3000 mPas. The viscosity of the polyol composition (X) can be adjusted by the skeleton of the polyol compound, the plasticizer described below, and the like. When adjusting with the skeleton of a polyol compound, the viscosity can be lowered by using, for example, polypropylene glycol or a polyester polyol obtained by reacting an aliphatic carboxylic acid with a polyol. Alternatively, the viscosity can be increased by using a polyester polyol obtained by reacting an aromatic carboxylic acid with a polyol.

(Polyisocyanate composition (Y))
The polyisocyanate composition (Y) contains a urethane prepolymer obtained by the production method of the present invention. Furthermore, other isocyanate compounds can be used in combination as long as the effects of the present invention are not adversely affected. As the isocyanate compound that can be used in combination with the urethane prepolymer, the same compounds as those exemplified as those that can be used in the third step in the production method of the present invention can be used.

When the adhesive of the present invention is used as a solvent-free adhesive, the viscosity of the polyisocyanate composition (Y) is adjusted to a range suitable for the non-solvent laminating method. As an example, the viscosity at 40° C. is adjusted to be in the range of 500 to 5000 mPas, more preferably 500 to 3000 mPas. The viscosity of the polyisocyanate composition (Y) can be adjusted, for example, by adjusting the amount of the urethane prepolymer and the isocyanate monomer.

(Other components of adhesive)
The adhesive of the present invention may contain components other than those described above. Other components may be included in either or both of the polyol composition (X) and the polyisocyanate composition (Y), or they may be prepared separately from the polyol composition (X) and the polyisocyanate composition (Y), and added to the polyol composition immediately before applying the adhesive. It may be used in combination with the composition (X) and the polyisocyanate composition (Y). Each component will be explained below.

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

Examples of the metal catalyst include metal complex catalysts, inorganic metal catalysts, and organic metal catalysts. Metal complex catalysts include a group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt). Examples of acetylacetonate salts of metals selected from among these include iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, and zirconia acetylacetonate.

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

Examples of organometallic catalysts include organic zinc compounds such as zinc octylate, zinc neodecanoate, and zinc naphthenate, stannath diacetate, stannath dioctoate, stannath dioleate, stannath dilaurate, dibutyltin diacetate, and dibutyltin dilaurate. , organic tin compounds such as dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride, organic nickel compounds such as nickel octylate and nickel naphthenate, organic cobalt compounds such as cobalt octylate and cobalt naphthenate, bismuth octylate, and neodecanoic acid. At least one of organic bismuth compounds such as bismuth and bismuth naphthenate, tetraisopropyloxytitanate, dibutyltitanium dichloride, tetrabutyltitanate, butoxytitanium trichloride, aliphatic diketones, aromatic diketones, and alcohols having 2 to 10 carbon atoms. Examples include titanium-based compounds such as titanium chelate complexes used as ligands.

Examples of 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- Examples include (2-hydroxyethyl)imidazole, 1-(2-hydroxypropyl)imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, and 1-(2-hydroxypropyl)-2-methylimidazole.

Examples of the aliphatic cyclic amide compound include δ-valerolactam, ε-caprolactam, ω-enanthollactam, η-capryllactam, β-propiolactam, and the like. Among these, ε-caprolactam is more effective in accelerating curing.

(acid anhydride)
Examples of the acid anhydride include cyclic aliphatic acid anhydrides, aromatic acid anhydrides, unsaturated carboxylic acid anhydrides, etc., and one type or a combination of two or more types can be used. More specifically, for example, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, dodecenylsuccinic anhydride, polyadipic anhydride, polyazelaic anhydride, polysebacic acid Anhydride, poly(ethyl octadecanedioic acid) anhydride, poly(phenylhexadecanedioic acid) anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride , methylhimic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexenedicarboxylic anhydride, methylcyclohexenetetracarboxylic anhydride, ethylene glycol bistrimelitate dianhydride, Het's acid anhydride, nadic acid anhydride, Methylnadic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic anhydride, 3,4-dicarboxy-1,2, Examples include 3,4-tetrahydro-1-naphthalenesuccinic dianhydride and 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride.

Further, as the acid anhydride, a compound obtained by modifying the above-mentioned compound with glycol may be used. Glycols that can be used for 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. Furthermore, a copolymerized polyether glycol of two or more types of glycols and/or polyether glycols can also be used.

(coupling agent)
Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent.

Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-amino Aminosilanes such as propyltrimethyldimethoxysilane, 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-mercaptopropyltrimethoxysilane, etc. Examples include methoxysilane.

Examples of titanate coupling agents include tetraisopropoxy titanium, tetra-n-butoxy titanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxy titanate. Examples include titanium.

Examples of the aluminum coupling agent include acetalkoxyaluminum diisopropylate.

(pigment)
There are no particular restrictions on the pigments; extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, blue pigments, Examples include organic pigments and inorganic pigments such as metal powder pigments, luminescent pigments, and pearlescent pigments, as well as plastic pigments.

Examples of extender pigments include precipitated barium sulfate, powder, precipitated calcium carbonate, calcium bicarbonate, agarite, alumina white, silica, hydrated fine powder silica (white carbon), ultrafine anhydrous silica (Aerosil), and silica sand (silica). sand), talc, precipitated magnesium carbonate, bentonite, clay, kaolin, loess, etc.

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 types (copper) such as phthalocyanine blue and phthalocyanine green; Phthalocyanine pigments; various chlorine dyeing lakes such as rhodamine lake and methyl violet lake; various mordant dye pigments such as quinoline lake and fast sky blue; various types of anthraquinone pigments, thioindigo pigments, perinone pigments, etc. Examples include vat dye pigments; various quinacridone pigments such as Cyncasia Red B; various dioxazine pigments such as dioxazine violet; various condensed azo pigments such as chromophthal; and aniline black.

Inorganic pigments include various chromates such as yellow lead, zinc chromate, molybdate orange, etc.; various ferrocyanic compounds such as navy blue; titanium oxide, zinc white, mapico yellow, iron oxide, red iron oxide, chrome oxide green, Various metal oxides such as zirconium oxide; Various sulfides or selenides such as cadmium yellow, cadmium red, and mercury sulfide; Various sulfates such as barium sulfate and lead sulfate; Various silicates 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 violet; Various metal powder pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder, and brass powder; Examples include flake pigments of these metals, mica flake pigments; mica flake pigments coated with metal oxides, metallic pigments such as mica-like iron oxide pigments, pearl pigments; graphite, carbon black, and the like.

Examples of the plastic pigment include "Grandeur PP-1000" and "PP-2000S" manufactured by DIC Corporation.

The pigment to be used may be appropriately selected depending on the purpose, but for example, it is preferable to use inorganic oxides such as titanium oxide and zinc white as white pigments because of their excellent durability, weather resistance, and design. It is preferable to use carbon black as the pigment.

The blending amount of the pigment is, for example, 1 to 400 parts by mass based on 100 parts by mass of the total nonvolatile content of the polyol composition (X) and the polyisocyanate composition (Y), to improve adhesiveness and blocking resistance. It is more preferable to adjust the amount to 10 to 300 parts by mass in order to obtain a desired amount.

(Plasticizer)
Examples of plasticizers include phthalic acid plasticizers, fatty acid plasticizers, aromatic polycarboxylic acid plasticizers, phosphoric acid plasticizers, polyol plasticizers, epoxy plasticizers, polyester plasticizers, and carbonate plasticizers. Examples include plasticizers.

Examples of phthalic acid plasticizers include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, diheptyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, and dinonyl. Phthalate, diisononyl phthalate, didecyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, dilauryl phthalate, distearyl phthalate, diphenyl phthalate, dibenzyl phthalate, butylbenzyl phthalate, dicyclohexyl phthalate, octyldecyl phthalate, dimethyl isophthalate, Phthalate ester plasticizers such as di-(2-ethylhexyl) isophthalate and diisooctyl isophthalate; tetrahydroplastics such as di-(2-ethylhexyl)tetrahydrophthalate, di-n-octyltetrahydrophthalate and diisodecyltetrahydrophthalate; Examples include phthalate ester plasticizers.

Examples of fatty acid plasticizers include adipic acids such as di-n-butyl adipate, di-(2-ethylhexyl) adipate, diisodecyl adipate, diisononyl adipate, di(C6-C10 alkyl) adipate, and dibutyl diglycol adipate. azelaic acid plasticizers such as di-n-hexyl azelate, di-(2-ethylhexyl) azelate, diisooctyl azelate, e.g. di-n-butyl sebacate, di-(2- Sebacic acid plasticizers such as ethylhexyl) sebacate and diisononyl sebacate, maleic acid plasticizers such as dimethyl maleate, diethyl maleate, di-n-butyl maleate, and di-(2-ethylhexyl) maleate, e.g. , di-n-butyl fumarate, di-(2-ethylhexyl) fumarate, and other fumaric acid plasticizers, such as monomethyl itaconate, monobutyl itaconate, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, Itaconic acid plasticizers such as di-(2-ethylhexyl) itaconate, for example, stearic acid plasticizers such as n-butyl stearate, glycerin monostearate, diethylene glycol distearate, for example butyl oleate, glyceryl monooleate, Oleic acid plasticizers such as diethylene glycol monooleate; citric acids such as triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, acetyl tri-(2-ethylhexyl) citrate; ricinoleic acid plasticizers such as methyl acetyl ricinoleate, butylacetyl ricinoleate, glyceryl monoricinolate, diethylene glycol monoricinolate, diethylene glycol monolaurate, diethylene glycol dipelargonate, pentaerythritol fatty acid ester, etc. and other fatty acid plasticizers.

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

Examples of phosphoric acid plasticizers include triethyl phosphate, tributyl phosphate, tri-(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, cresyl phenyl phosphate, and tricresyl phosphate. Examples include dilyphosphate, tricylenylphosphate, tris(chloroethyl)phosphate, tris(chloropropyl)phosphate, tris(dichloropropyl)phosphate, tris(isopropylphenyl)phosphate, and the like.

Examples of polyol plasticizers include diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di-(2-ethyl butyrate), and triethylene glycol di-(2-ethylhexoate). ), glycol-based plasticizers such as dibutylmethylene bisthioglycolate, and glycerin-based plasticizers such as glycerol monoacetate, glycerol triacetate, and glycerol tributyrate.

Examples of epoxy plasticizers include epoxidized soybean oil, epoxybutyl stearate, di2-ethylhexyl epoxyhexahydrophthalate, diisodecyl epoxyhexahydrophthalate, epoxy triglyceride, epoxidized octyl oleate, and epoxidized decyl oleate. Examples include.

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

Examples of carbonate plasticizers include propylene carbonate and ethylene carbonate.

In addition, examples of the plasticizer include partially hydrogenated terphenyl, adhesive plasticizers, and polymerizable plasticizers such as diallyl phthalate, acrylic monomers, and oligomers. These plasticizers can be used alone or in combination of two or more.

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

(Form of adhesive)
The adhesive of the present invention may be in either a solvent type or a solvent-free type, but in particular, since it does not contain an organic solvent, storage of a urethane prepolymer synthesized with 4,4'-MDI as a main component is preferred. It is suitable for solvent-free types that tend to have insufficient stability. In this specification, a "solvent type" adhesive refers to an adhesive that is applied to a base material, heated in an oven, etc. to volatilize the organic solvent in the coating film, and then bonded to another base material. This refers to the form used in the so-called dry lamination method. Either one or both of the polyol composition (X) and the polyisocyanate composition (Y) dissolves (dilutes) the constituent components of the polyol composition (X) and polyisocyanate composition (Y) used in the present invention. Contains organic solvents that can be used.

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. , halogenated hydrocarbons such as methylene chloride and ethylene chloride, dimethyl sulfoxide, dimethyl sulfamide, and the like. The organic solvent used as a reaction medium during the production of the constituent components of the polyol composition (X) or polyisocyanate composition (Y) may also be used as a diluent during coating.

In this specification, a "solvent-free" adhesive refers to an adhesive in which the polyol composition (X) and the polyisocyanate composition (Y) are esters such as ethyl acetate, butyl acetate, cellosolve acetate, acetone, methyl ethyl ketone, isobutyl ketone, Highly soluble in ketones such as cyclohexanone, ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, dimethyl sulfoxide and dimethyl sulfamide, etc. A method that substantially does not contain an organic solvent, particularly ethyl acetate or methyl ethyl ketone, and that is bonded to another base material without the step of applying an adhesive to a base material and then heating it in an oven or the like to evaporate the solvent; Refers to the form of adhesive used in the so-called non-solvent laminating method. The constituent components of polyol composition (X) or polyisocyanate composition (Y) or the organic solvent used as a reaction medium during the production of the raw materials may not be completely removed, resulting in polyol composition (X) or polyisocyanate composition ( If a trace amount of organic solvent remains in Y), it is considered that the organic solvent is not substantially contained. Further, when the polyol composition (X) contains a low molecular weight alcohol, the low molecular weight alcohol reacts with the polyisocyanate composition (Y) and becomes a part of the coating film, so there is no need to volatilize it after coating. Therefore, such forms are also treated as solvent-free adhesives, and low molecular weight alcohols are not considered organic solvents.

The adhesive of the present invention has a ratio of the number of moles of isocyanate groups [NCO] contained in the polyisocyanate composition (Y) to the number of moles of hydroxyl groups [OH] contained in the polyol composition (X) [NCO]/[ It is preferable to mix and use them so that the OH] is 1.0 to 3.0. Thereby, appropriate curability can be obtained without depending on the environmental humidity at the time of coating.

<Laminated body>
The adhesive using the urethane prepolymer obtained by the production method of the present invention can be suitably used for producing a laminate, particularly a laminate for food packaging. Such a laminate is obtained by laminating a plurality of base materials (films or papers) together using the above-mentioned adhesive by a dry lamination method or a non-solvent lamination method. There is no particular restriction on the film used, and a film can be appropriately selected depending on the purpose. 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), polypropylene film (CPP: unstretched Examples include polyolefin films such as polypropylene film and OPP (biaxially oriented polypropylene film), polyvinyl alcohol films, and ethylene-vinyl alcohol copolymer films.

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 such as those listed in the list of biomass certified products listed by the Japan Organic Resources Association can be used.

Specifically, well-known biomass films include those made from biomass-derived ethylene glycol. Biomass-derived ethylene glycol is made from ethanol produced from biomass (biomass ethanol). For example, biomass-derived ethylene glycol can be obtained by converting biomass ethanol into ethylene glycol via ethylene oxide using a conventionally known method. Moreover, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol Corporation can be suitably used.

For example, as an alternative to conventional polyethylene terephthalate films that use petroleum-based raw materials, films containing biomass polyester, biomass polyethylene terephthalate, etc., whose diol units are biomass-derived ethylene glycol and dicarboxylic acid units from fossil fuel-derived dicarboxylic acids. It has been known.

The dicarboxylic acid unit of the biomass polyester uses dicarboxylic acid derived from fossil fuels. As the dicarboxylic acid, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof can be used without limitation.
In addition to the above-mentioned diol component and dicarboxylic acid component, bifunctional oxycarboxylic acids, trifunctional or more polyhydric alcohols, trifunctional or more polycarboxylic acids and/or their anhydrides may also be used to form a crosslinked structure. It may also be a copolymerized polyester in which a copolymerized component is added as a third component such as at least one type of polyfunctional compound selected from the group consisting of trifunctional and trifunctional or more functional oxycarboxylic acids.

In addition, for example, as an alternative to conventional polyolefin films that use 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. Film is also known.
Polyethylene resins are not particularly limited other than using ethylene glycol derived from biomass as a part of the raw material, and can be made of ethylene homopolymers, copolymers of ethylene and α-olefin with ethylene as the main component (ethylene Examples include ethylene-α-olefin copolymers containing 90% by mass or more of units, 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 include those having 4 or more carbon atoms, such as 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene. 8 α-olefins are mentioned. Known polyethylene resins such as low-density polyethylene resin, medium-density polyethylene resin, and linear low-density polyethylene resin can be used. Among these, from the viewpoint of making it even more difficult to cause damage such as holes and tears even if the films rub against each other, linear low-density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or a copolymer of ethylene and 1-hexene) is used. - a copolymer with octene) is preferred, and a linear low-density polyethylene resin having a density of 0.910 to 0.925 g/cm ³ is more preferred.

Biomass films using biomass raw materials classified by biomass plasticity as defined by ISO16620 or ASTM D6866 are also on the market. In the atmosphere, radioactive carbon 14C exists at a ratio of 1 in 1012, and this ratio does not change even with carbon dioxide in the atmosphere, so even in plants that fix this carbon dioxide through photosynthesis, this ratio does not change. Therefore, the carbon of the plant-derived resin contains 14C radioactive carbon. In contrast, the carbon of fossil fuel-derived resin contains almost no radioactive carbon 14C. Therefore, by measuring the concentration of radioactive carbon 14C in the resin using an accelerator mass spectrometer, it is possible to determine the content ratio of plant-derived resin in the resin, that is, the degree of biomass plasticity.

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

Films and sheets containing biomass raw materials such as starch and polylactic acid are also known. These can be appropriately selected and used depending on the purpose.

The biomass film may be a laminate of a plurality of biomass films, or a laminate of a conventional petroleum film and a biomass film. Further, these biomass films may be either unstretched films or stretched films, and the manufacturing method thereof is not limited.

The film may be subjected to a stretching process. As a stretching treatment method, the resin is melt-extruded to form a sheet by an extrusion film forming method or the like, and then simultaneous biaxial stretching or sequential biaxial stretching is performed. In addition, in the case of sequential biaxial stretching, it is common to perform longitudinal stretching first and then perform transverse stretching. Specifically, a method that combines longitudinal stretching using a speed difference between rolls and transverse stretching using a tenter is often used.

The surface of the film may be subjected to various surface treatments such as flame treatment and corona discharge treatment, if necessary, so that an adhesive layer free from defects such as film breakage and repellency is formed.

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

As the paper, any known paper base material can be used without particular limitation. Specifically, it is manufactured using a known paper machine using natural fibers for paper making such as wood pulp, but the paper making conditions are not particularly defined. Examples of natural fibers for papermaking include wood pulps such as softwood pulp and hardwood pulp, non-wood pulps such as Manila hemp pulp, sisal pulp, and flax pulp, and pulps obtained by chemically modifying these pulps. As for the type of pulp, chemical pulp produced by sulfate cooking method, acidic/neutral/alkaline sulfite cooking method, soda salt cooking method, etc., ground pulp, chemical ground pulp, thermomechanical pulp, etc. can be used. Furthermore, various types of commercially available high-quality paper, coated paper, lined paper, impregnated paper, cardboard, paperboard, etc. can also be used.

More specific and preferable configurations of the laminate that exhibit 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 These laminates are often subjected to boiling or retort processing. Used in necessary packaging materials.As PAA easily transfers from the adhesive layer to the contents during boiling and retort processing, adhesives used in laminates that undergo such processing are likely to have a rapid PAA reduction rate. However, the adhesive using the urethane prepolymer produced by the production method of the present invention meets these demands. It is preferable to use an adhesive.The adhesive layer', adhesive layer'' may or may not be formed using the above-mentioned adhesive.

Other preferred configuration examples include OPP film/adhesive layer/CPP film, OPP film/adhesive layer/LLDPE film, OPP/adhesive layer/aluminum deposited CPP film, PET film/adhesive layer/LLDPE film, PET film/adhesive layer/LLDPE film, Aluminum vapor deposited CPP film, Ny film/adhesive layer/LLDPE film, OPP film/adhesive layer'/aluminum vapor deposited PET film/adhesive layer/LLDPE film, PET film/adhesive layer'/aluminum vapor deposited PET film/adhesive layer/LLDPE film, Examples include, but are not limited to, Ny film/adhesive layer'/aluminum deposited PET film/adhesive layer/LLDPE film. Note that in the above configuration, the adhesive layer is a cured coating film of the above-mentioned adhesive. The adhesive layer' may be a cured coating film of the above-mentioned adhesive, or may be a cured coating film of another adhesive.

In the laminate, a printed layer may be provided between the adhesive layer and the base material (usually the base material that is the outermost layer with respect to the contents). The printing layer is formed using various printing inks such as gravure ink, flexographic ink, offset ink, stencil ink, and inkjet ink, by a general printing method conventionally used for printing on films.

When the adhesive is a solvent type, the adhesive of the present invention is applied to one base material using a roll such as a gravure roll, the organic solvent is evaporated by heating in an oven, etc., and then the other base material is coated with the adhesive of the present invention. The laminate of the present invention is obtained by bonding. 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 is a solvent-free type, the adhesive of the present invention, which has been preheated to about 40°C to 100°C, is applied to one base material using a roll such as a coat roll, and then immediately applied to the other base material. The materials are bonded together to obtain a 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 applied is adjusted as appropriate. In the case of a solvent-based adhesive, for example, the solid content is adjusted to be 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 solvent-free adhesive, the amount of adhesive applied 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 may be made by bonding two base materials together using the adhesive of the present invention, or may contain other base materials as necessary. As a method for laminating other base materials, known methods such as dry lamination, non-solvent lamination, thermal lamination, heat sealing, extrusion lamination, etc. may be used. The adhesive used at this time may or may not be the one described above. As other base materials, those similar to the base materials described above can be used.

<Packaging material>
The above-mentioned laminate can be suitably used as a packaging material, especially a packaging material for food packaging. The packaging material is obtained by forming the above-mentioned laminate into a bag shape and heat-sealing the bag. There are various types of packaging materials, such as three-sided sealed bags, four-sided sealed bags, gusseted packaging bags, pillow packaging bags, Goebel top type bottomed containers, Tetra Classic, Bruck type, tube containers, paper cups, and lidding materials. Furthermore, the packaging material may be appropriately provided with easy-opening treatment or resealing means.

The packaging material of the present invention can be suitably used not only for food applications but also as a packaging material for filling detergents and medicines. Specific applications include detergents and drugs such as liquid laundry detergent, kitchen liquid detergent, bath liquid detergent, bath liquid soap, liquid shampoo, liquid conditioner, and pharmaceutical tablets. It can also be used as a secondary packaging material for packaging the above-mentioned containers.

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

(Example 1)
[Synthesis of polyester polyol]
122 parts of ethylene glycol, 267 parts of neopentyl glycol, and 6 parts of trimethylolpropane were charged into a polyester reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, a Snyder tube, and a condenser, and the mixture was heated to 80 parts while stirring under a nitrogen gas flow. heated to ℃. Further, while stirring, 516 parts of adipic acid and 90 parts of isophthalic acid were charged into the reaction vessel, and the temperature was gradually increased to 240°C so that the temperature at the upper part of the Snyder tube did not exceed 100°C to carry out an esterification reaction. When the acid value became 5 mgKOH/g or less, the pressure in the reaction vessel was gradually reduced, and the reaction was carried out at 240°C for 2 hours at 1 mmHg or less. A polyester polyol containing 0.016% by mass of water was obtained.

[First step]
In a reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a condenser, the content of 2,2-diphenylmethane diisocyanate was 0.1% by mass, and the content of 2,4-diphenylmethane diisocyanate was 0.8% by mass. , 4,4′-diphenylmethane diisocyanate content is 80.8% by mass, and the content of Sumidur N3300 (manufactured by Sumika Covestro Urethane Co., Ltd.) is 18.3% by mass (i-1) 48. 6 parts were charged and heated to 60° C. with stirring under a nitrogen gas stream. Here, polyol composition (ii-1) containing 26.4 parts of polyester polyol, 11.9 parts of polypropylene glycol with a number average molecular weight of 2000, and 0.00264 parts of phosphoric acid and having a water content of 0.042% was added several times. The urethane prepolymer having an isocyanate group at both ends, an NCO% of 15.0%, and a viscosity of 3873 mPa・s is obtained by adding dropwise in portions and further heating and holding at an internal temperature of 80°C for 3 hours to perform a urethane reaction. (I-1) was obtained.

[Second process]
The urethane prepolymer (I-1) in the reaction vessel was heated to 100°C over 1 hour while stirring under a stream of nitrogen gas, and was maintained for an additional 3 hours to carry out the reaction, resulting in an NCO% of 14.7% and a viscosity of A urethane prepolymer (II-1) of 4377 mPa·s was obtained.

[Third step]
The urethane prepolymer (II-1) in the reaction vessel was cooled to 50°C, 13.1 parts of carbodiimide-modified diphenylmethane diisocyanate (product name Lupranate MM103, manufactured by BASF) was added thereto, and the mixture was stirred until uniform. A urethane prepolymer of Example 1 with a percentage of 16.7% was obtained.

(Example 2) - (Example 8)
Except that the polyisocyanate composition (i) used, the polyol composition (ii), the heat treatment conditions of the first step and the second step, and the amount of additives in the third step were changed as shown in Tables 1 and 2. Urethane prepolymers of Examples 2 to 8 were synthesized in the same manner as in Example 1.

(Comparative example 1)
Example 1 except that the polyisocyanate composition (i) used, the polyol composition (ii), the additive amounts in the first step and the third step were changed as shown in Table 2, and the second step was omitted. Urethane prepolymer of Comparative Example 1 was synthesized in the same manner.
(Comparative example 2)
Example 1 except that the polyisocyanate composition (i) used, the polyol composition (ii), the heat treatment conditions in the first step and the second step, and the amount of additive in the third step were changed as shown in Table 2. Urethane prepolymers of Comparative Examples 1 and 2 were synthesized in the same manner.

In the table, the NCO% and viscosity of the first step represent the NCO% and viscosity at the end of the first step, respectively, and the NCO% and viscosity of the second step represent the NCO% and viscosity at the end of the second step, respectively. The NCO% reduction rate represents the NCO% at the end of the second step relative to the NCO% at the end of the first step, and the viscosity increase represents the ratio of the viscosity at the end of the second step to the viscosity at the end of the first step.

<Evaluation>
(Storage stability)
A 15 ml glass bottle was filled with the urethane prepolymers of Examples and Comparative Examples, and after being stored at room temperature for a certain period of time, the appearance of the bottle was visually evaluated for turbidity.
The evaluation was as follows.
◎: Not cloudy for more than 2 months ○: Turbidity occurs in 1 to 2 months ×: Turbidity occurs within 1 month

Claims (8)

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, and the content of 4,4'- diphenylmethane diisocyanate isocyanate composition (i) in which the isocyanate composition (i) is 75.0% by mass or more and polyol composition (ii) are combined such that the isocyanate groups contained in the isocyanate groups are in excess of the active hydrogen groups contained in the polyol composition. A first step of obtaining urethane prepolymer (I) by reacting at 65° C. or higher and 85° C. or lower for 2 hours or more under the following conditions;
a second step of heat-treating the urethane prepolymer (I) at 95° C. or higher and 110° C. or lower to obtain urethane prepolymer (II);
including;
The second step is a method for producing a urethane prepolymer for a two-component curable adhesive, wherein the second step is performed until the NCO% of the urethane prepolymer (II) becomes 99% or less of the NCO% of the urethane prepolymer (I). The manufacturing method according to claim 1, comprising the step of adjusting the water content of the polyol composition (ii) to 0.01% by mass or more and 0.5% by mass or less. 2. The polyol composition (ii) contains at least one monoamine selected from primary monoamines and secondary monoamines, and the content of the monoamine in the polyol composition (ii) is 10% by mass or less. manufacturing method. The manufacturing method according to claim 1, wherein the second step is performed until the viscosity of the urethane prepolymer (II) at 25°C becomes 1.1 times or more the viscosity of the urethane prepolymer (I). The manufacturing method according to claim 1, wherein the second step is completed before the viscosity of the urethane prepolymer (II) at 25°C exceeds 15.0 times the viscosity of the urethane prepolymer (I). In the first step, the actual value of NCO% at the end of the first step is the isocyanate group contained in the isocyanate composition (i) and the isocyanate group contained in the polyol composition (ii). It is less than the calculated value of NCO% of the urethane prepolymer (I) when all the active hydrogen groups have reacted, calculated from the molar ratio with the active hydrogen groups, and 2 hours before the first step is completed. The manufacturing method according to claim 1, wherein the manufacturing method is carried out until the difference from the previous measured value of NCO% becomes 0.05% or less. The manufacturing method according to claim 1, wherein the second step is completed before the NCO% of the urethane prepolymer (II) falls below 80% of the NCO% of the urethane prepolymer (I). The manufacturing method according to any one of claims 1 to 7, wherein the polyol composition (ii) contains at least one of a polyether polyol or a polyester polyol.