JPWO2019146756A1 - Two-component curable solvent-free adhesive and laminate film - Google Patents

Abstract

In a two-component curable solvent-free adhesive containing a polyisocyanate component and a polyol component, the polyisocyanate component contains an isocyanate group-terminated prepolymer which is a reaction product of diphenylmethane diisocyanate and a polyol, and unreacted diphenylmethane diisocyanate. The polyol component contains a polyester polyol having a number average molecular weight of 1000 or less, and the amount of unreacted diphenylmethane diisocyanate is 20 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the two-component curable solvent-free adhesive. The two-component curable solvent-free adhesive contains 0.003 parts by mass or more and 0.030 parts by mass or less of phosphoric acid with respect to 100 parts by mass of the total amount.

Description

The present invention relates to a two-component curable solvent-free adhesive and a laminate film. Specifically, a two-component curable solvent-free adhesive suitable as a laminate adhesive and a two-component curable solvent-free adhesive thereof are used. Regarding the laminated film obtained by using.

Laminated films, in which various films are attached with a laminating adhesive, are widely used in the field of packaging materials. In particular, a laminated film in which a plastic film and a metal foil are attached with a laminating adhesive is excellent in light-shielding property and barrier property of gas and liquid, and is widely used as various packaging materials.

Laminate adhesives used in such laminate films include a diisocyanate group-terminated prepolymer, which is a reaction product of xylylene diisocyanate and polyester diol, a polyisocyanate component containing an allophanate modified product of hexamethylene diisocyanate, and a polyester diol. A two-component curable solvent-free adhesive containing the acid-modified product of the above and a polyol component containing trimethylolpropane has been proposed, and further, no phosphoric acid is applied to 100 parts of the two-component curable solvent-free adhesive. It has also been proposed to add .033 parts and 0.67 parts of γ-glycidoxypropyltrimethoxysilane (see, for example, Patent Document 1 (Example 1)).

Japanese Unexamined Patent Publication No. 2011-162656

On the other hand, in the two-component curable solvent-free adhesive described in Patent Document 1, it is necessary to remove unreacted xylylene diisocyanate in the polyisocyanate component by thin film distillation or the like from the viewpoint of work hygiene environment, which is troublesome. There is a problem that it takes.

On the other hand, since diphenylmethane diisocyanate has a relatively high vapor pressure, it is not necessary to remove unreacted diphenylmethane diisocyanate from the viewpoint of working hygiene environment.

However, depending on the residual ratio of unreacted diphenylmethane diisocyanate in the two-component curable solvent-free adhesive, an appropriate pot life cannot be obtained, and as a result, there is a problem that an appearance defect is caused.

Further, as a two-component curable solvent-free adhesive, low-temperature curability (room temperature curing property) is required, and further, a laminated film having excellent content resistance is required depending on the application.

The present invention is a two-component curable type that is excellent in production efficiency, has an appropriate pot life, can suppress appearance defects, is excellent in low temperature curability, and can produce a laminated film having excellent content resistance. It is a laminate film obtained by using a solvent-based adhesive and its two-component curable solvent-free adhesive.

The present invention [1] is a two-component curable solvent-free adhesive containing a polyisocyanate component and a polyol component, wherein the polyisocyanate component is an isocyanate group-terminated prepolymer which is a reaction product of diphenylmethane diisocyanate and a polyol. , Unreacted diphenylmethane diisocyanate, the polyol component contains a polyester polyol having a number average molecular weight of 1000 or less, and the unreacted diphenylmethane with respect to 100 parts by mass of the two-component curable solvent-free adhesive. The diisocyanate is 20 parts by mass or more and 30 parts by mass or less, and the phosphoric acid is contained in 0.003 parts by mass or more and 0.030 parts by mass or less with respect to 100 parts by mass of the total amount of the two-component curable solvent-free adhesive. Includes a two-component curable solvent-free adhesive.

The present invention [2] contains 0.2 parts by mass or more and 5.0 parts by mass or less of a silane coupling agent with respect to 100 parts by mass of the total amount of the two-component curable solvent-free adhesive. ] The two-component curable solvent-free adhesive described in the above is included.

The present invention [3] includes the two-component curable solvent-free adhesive according to the above [1] or [2], wherein the polyol component contains a trihydric or higher alcohol.

The present invention [4] includes a laminated film including an adhesive layer made of the two-component curable solvent-free adhesive according to any one of the above [1] to [3].

The two-component curable solvent-free adhesive of the present invention contains a polyisocyanate component and a polyol component, and further contains unreacted diphenylmethane diisocyanate and phosphoric acid in a predetermined ratio.

Therefore, the two-component curable solvent-free adhesive of the present invention has excellent production efficiency, has an appropriate pot life, can suppress appearance defects, has excellent low-temperature curability, and has content resistance. It is possible to manufacture an excellent laminated film.

Further, since the laminated film of the present invention contains the adhesive layer made of the above-mentioned two-component curable solvent-free adhesive, it is excellent in production efficiency, appearance and content resistance.

The two-component curable solvent-free adhesive of the present invention does not contain an organic solvent and water, but contains a polyisocyanate component and a polyol component. In the two-component curable solvent-free adhesive, the polyisocyanate component and the polyol component are individually prepared and mixed immediately before use.

The polyisocyanate component contains an isocyanate group-terminated prepolymer which is a reaction product of diphenylmethane diisocyanate and a polyol, and unreacted diphenylmethane diisocyanate.

Examples of the diphenylmethane diisocyanate include 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,2'-diphenylmethane diisocyanate.

These diphenylmethane diisocyanates can be used alone or in combination of two or more.

The diphenylmethane diisocyanate preferably contains 4,4'-diphenylmethane diisocyanate and, if necessary, 2,4'-diphenylmethane diisocyanate and / or 2,2'-diphenylmethane diisocyanate. More preferably, the diphenylmethane diisocyanate contains 4,4'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate (liquid diphenylmethane diisocyanate). The ratio thereof is appropriately set according to the purpose and use.

Examples of the polyol include a low molecular weight polyol and a high molecular weight polyol.

Examples of the low molecular weight polyol include organic compounds having two or more hydroxyl groups in the molecule and having a molecular weight of 50 or more and 300 or less, preferably 400 or less.

Specific examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, and 1,5-. Pentandiol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, 3,3-dimethylolheptan, alcohol (C7-20) diol , 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof, 1,3- or 1,4-cyclohexanediol and mixtures thereof, bisphenol hydride A, 1,4-dihydroxy-2-butene, 2, , 6-Dimethyl-1-octene-3,8-diol, bisphenol A, diethylene glycol, triethylene glycol, dipropylene glycol and other dihydric alcohols, such as glycerin, trimethylolpropane, triisopropanolamine and other trihydric alcohols. For example, tetrahydric alcohols such as tetramethylolmethane (pentaerythritol) and diglycerin, for example, pentahydric alcohols such as xylitol, for example, sorbitol, mannitol, alitol, iditol, darsitol, altritor, inositol, dipentaerythritol and the like 6 Hyvalent alcohols, for example, heptavalent alcohols such as persetol, for example, octahydric alcohols such as sucrose and the like can be mentioned.

These low molecular weight polyols can be used alone or in combination of two or more.

As the low molecular weight polyol, preferably, a trihydric alcohol is mentioned, and more preferably, trimethylolpropane is mentioned.

Examples of the high molecular weight polyol include high molecular weight compounds (preferably polymers) having two or more hydroxyl groups in the molecule and having a number average molecular weight of more than 300, preferably more than 400.

Specific examples of the high molecular weight polyol include a polyether polyol, a polyester polyol, a polycarbonate polyol, a polyurethane polyol, an epoxy polyol, a vegetable oil polyol, a polyolefin polyol, an acrylic polyol, and a vinyl monomer-modified polyol.

Preferred high molecular weight polyols include polyether polyols, polyester polyols, and polycarbonate polyols.

Examples of the polyether polyol include polyoxyalkylene polyol, polytrimethylene ether glycol, polytetramethylene ether polyol and the like.

Examples of the polyether polyol include a polyoxyalkylene polyol and a polytetramethylene ether polyol.

Examples of the polyoxyalkylene polyol include an addition polymer of an alkylene oxide having the above-mentioned low molecular weight polyol or a known low molecular weight polyamine as an initiator.

Examples of the alkylene oxide include propylene oxide, ethylene oxide, butylene oxide and the like. In addition, these alkylene oxides can be used alone or in combination of two or more. Moreover, among these, propylene oxide and ethylene oxide are preferable. In addition, polyoxyalkylene polyols include, for example, polyethylene glycol, polypropylene glycol, random and / or block copolymers of propylene oxide and ethylene oxide.

Examples of the polytrimethylene ether glycol include glycols obtained by a polycondensation reaction of 1,3-propanediol derived from a plant component.

Examples of the polytetramethylene ether polyol include a ring-opening polymer obtained by cationic polymerization of tetrahydrofuran (polytetramethylene ether glycol (crystalline)), alkyl-substituted tetrahydrofuran in a polymerization unit such as tetrahydrofuran, and the above-mentioned divalent. Examples thereof include amorphous (non-crystalline) polytetramethylene ether glycol obtained by copolymerizing alcohol.

Examples of the polyester polyol include a polycondensate obtained by reacting a low molecular weight polyol with a polybasic acid under known conditions.

Examples of the low molecular weight polyol include the above-mentioned low molecular weight polyol, preferably a dihydric alcohol, and more preferably propylene glycol and neopentyl glycol.

Examples of the polybasic acid include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, and 3-methyl-3-ethylglutaric acid. , Saturated aliphatic dicarboxylic acids (C11-13) such as azelaic acid, sebacic acid, eg unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, eg phthalic acid, isophthalic acid, terephthalic acid, toluene Aromatic dicarboxylic acids such as dicarboxylic acids and naphthalenedicarboxylic acids, such as alicyclic dicarboxylic acids such as hexahydrophthalic acid, other carboxylic acids such as dimer acid, hydrogenated dimer acid, het acid, and their carboxylic acids. Acid anhydrides derived from acids such as oxalic acid anhydride, succinic acid anhydride, maleic anhydride, phthalic acid anhydride, 2-alkyl anhydride (C12-C18) succinic acid, tetrahydrophthalic acid anhydride, trimellitic acid anhydride, and further. Examples include acid halides derived from these carboxylic acids and the like, such as oxalic acid dichloride, adipic acid dichloride, and sebacic acid dichloride.

These polybasic acids can be used alone or in combination of two or more.

Examples of the polybasic acid preferably include saturated aliphatic dicarboxylic acid, aromatic dicarboxylic acid, and acid anhydride, more preferably adipic acid, phthalic acid, and phthalic anhydride, and further preferably adipic acid. Can be mentioned.

Further, as the polyester polyol, for example, a plant-derived polyester polyol, specifically, the above-mentioned low molecular weight polyol as an initiator, a hydroxyl group-containing vegetable oil fatty acid (for example, lysinoleic acid-containing castor oil fatty acid, 12-hydroxystearic acid) Examples thereof include vegetable oil-based polyester polyols obtained by subjecting a hydroxycarboxylic acid such as (hydrogenated castor oil fatty acid, etc.) containing the above to a condensation reaction under known conditions.

Further, as the polyester polyol, for example, using the above-mentioned low molecular weight polyol (preferably dihydric alcohol) as an initiator, lactones such as ε-caprolactone and γ-valerolactone, and for example, L-lactide and D- Examples thereof include polycaprolactone polyols and polyvalerolactone polyols obtained by ring-opening polymerization of lactides such as lactide, and lactone-based polyester polyols obtained by copolymerizing them with the above dihydric alcohol.

Examples of the polycarbonate polyol include a ring-opening polymer (crystalline) of ethylene carbonate using the above-mentioned low molecular weight polyol (preferably the above-mentioned dihydric alcohol) as an initiator, and for example, 1,4-butanediol, 1, Examples thereof include an amorphous polycarbonate polyol obtained by copolymerizing a dihydric alcohol such as 5-pentanediol, 3-methyl-1,5-pentanediol or 1,6-hexanediol with a ring-opening polymer.

These high molecular weight polyols can be used alone or in combination of two or more.

Preferred high molecular weight polyols include polyester polyols and polyether polyols.

The number average molecular weight of the high molecular weight polyol is, for example, more than 300, preferably more than 400, more preferably 500 or more, still more preferably 600 or more. Further, for example, it is 5000 or less, preferably 4000 or less, more preferably 2000 or less, and further preferably 1000 or less.

The number average molecular weight of the high molecular weight polyol can be measured by the GPC method (standard polystyrene conversion), and can be calculated in detail from the hydroxyl value and the average number of functional groups, as will be described later.

These polyols can be used alone or in combination of two or more.

As the polyol, preferably, a high molecular weight polyol is mentioned, and more preferably, a combination of a polyether polyol and a polyester polyol is mentioned.

When the polyether polyol and the polyester polyol are used in combination, the ratio of their combined use is, for example, 50 parts by mass or more, preferably 60 parts by mass or more of the polyether polyol with respect to 100 parts by mass of their total amount. Yes, for example, 90 parts by mass or less, preferably 80 parts by mass or less. The polyester polyol is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, and for example, 50 parts by mass or less, preferably 40 parts by mass or less.

By using these in combination, it is possible to achieve both excellent coatability derived from a polyether polyol and excellent adhesiveness derived from a polyester polyol.

Then, in order to obtain an isocyanate group-terminated prepolymer, the above-mentioned diphenylmethane diisocyanate and a polyol are reacted by a polymerization method (preferably bulk polymerization) such as bulk polymerization or solution polymerization.

In bulk polymerization, for example, the reaction temperature of diphenylmethane diisocyanate and polyol under a nitrogen stream is, for example, 50 ° C. or higher, for example 250 ° C. or lower, preferably 200 ° C. or lower, for example, 0.5 hour or longer, for example. , React for 15 hours or less.

In solution polymerization, diphenylmethane diisocyanate and polyol are added to an organic solvent, and the reaction temperature is, for example, 50 ° C. or higher, for example, 120 ° C. or lower, preferably 100 ° C. or lower, for example, 0.5 hours or longer, for example. , React for 15 hours or less.

Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, for example, nitriles such as acetonitrile, and alkyl esters such as methyl acetate, ethyl acetate, butyl acetate and isobutyl acetate, for example, n-. Aliper hydrocarbons such as hexane, n-heptane, octane, eg, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, eg aromatic hydrocarbons such as toluene, xylene, ethylbenzene, eg, methyl cellosolve acetate. , Ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate and other glycol ether esters. Classes, such as ethers such as diethyl ether, tetrahydrofuran, dioxane, for example, halogenated aliphatic hydrocarbons such as methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, methylene iodide, dichloroethane, for example. Examples thereof include polar aprotons such as N-methylpyrrolidone, dimethylformamide, N, N'-dimethylacetamide, dimethylsulfoxide and hexamethylphosphonylamide.

When solution polymerization is adopted, the organic solvent is removed after the completion of the polymerization reaction, as will be described later.

Further, in the above polymerization reaction, for example, a known urethanization catalyst such as amines or an organometallic compound can be added, if necessary.

Examples of amines include tertiary amines such as triethylamine, triethylenediamine, bis- (2-dimethylaminoethyl) ether and N-methylmorpholine, and quaternary ammonium salts such as tetraethylhydroxylammonium, for example, imidazole. Examples thereof include imidazoles such as 2-ethyl-4-methylimidazole.

Examples of the organic metal compound include tin acetate, tin octylate (tin octylate), tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dimercaptide, dibutyltin maleate, and dibutyl. Organic tin compounds such as tin dilaurate, dibutyl tin dineodecanoate, dioctyl tin dimercaptide, dioctyl tin dilaurylate, dibutyl tin dichloride, eg organic lead compounds such as lead octanoate, lead naphthenate, eg nickel naphthenate. Examples include organic nickel compounds, for example, organic cobalt compounds such as cobalt naphthenate, for example, organic copper compounds such as copper octenoate, for example, bismuth octanate (bismuth octylate), bismuth neodecanoate and the like. Preferred examples include tin octylate and bismuth octylate.

Further, examples of the urethanization catalyst include potassium salts such as potassium carbonate, potassium acetate and potassium octylate.

These urethanization catalysts can be used alone or in combination of two or more.

The addition ratio of the urethanization catalyst is, for example, 0.001 part by mass or more, preferably 0.01 part by mass or more, and for example, 1 part by mass or less, based on 10000 parts by mass of the total amount of diphenylmethane diisocyanate and polyol. It is preferably 0.5 parts by mass or less.

When an organic solvent is used in the above polymerization reaction, the organic solvent is removed by a known removing means such as distillation or extraction to make it solvent-free.

The mixing ratio of the diphenylmethane diisocyanate and the polyol is preferably adjusted so that the remaining unreacted diphenylmethane diisocyanate has a ratio described later. More specifically, the equivalent ratio (isocyanate group / hydroxyl group) of the isocyanate group in the diphenylmethane diisocyanate to the hydroxyl group in the polyol exceeds, for example, 4.0, preferably 4.1 or more, more preferably. It is 4.5 or more, more preferably 5.0 or more, for example, less than 8.0, preferably 7.5 or less, more preferably 7.0 or less, still more preferably 6.5 or less. ..

On a mass basis, the amount of diphenylmethane diisocyanate is, for example, 52 parts by mass or more, preferably 55 parts by mass or more, and for example, 65 parts by mass or less, preferably 65 parts by mass or more, based on 100 parts by mass of the total amount of diphenylmethane diisocyanate and polyol. , 60 parts by mass or less. The polyol is, for example, 35 parts by mass or more, preferably 40 parts by mass or more, and for example, 48 parts by mass or less, preferably 45 parts by mass or less.

As a result, an isocyanate group-terminated prepolymer can be obtained.

The isocyanate group content (isocyanate group content) can be determined by a known method such as a titration method using di-n-butylamine or FT-IR analysis.

The polyisocyanate component contains unreacted diphenylmethane diisocyanate.

The unreacted diphenylmethane diisocyanate is contained in the reaction product, for example, as an unreacted component in the production of the above-mentioned isocyanate group-terminated prepolymer.

Further, for example, a part of unreacted diphenylmethane diisocyanate can be removed from the obtained reaction product by a distillation method, an extraction method or the like to adjust the content of diphenylmethane diisocyanate.

Further, for example, the content of diphenylmethane diisocyanate can be adjusted by separately adding diphenylmethane diisocyanate to the obtained reaction product.

Preferably, the equivalent ratio in the production of the above isocyanate group-terminated prepolymer is adjusted so that the ratio of the unreacted diphenylmethane diisocyanate and the isocyanate group-terminated prepolymer is in the range described later, and the obtained reaction product is used as it is. Used as a polyisocyanate component.

The content ratio of unreacted diphenylmethane diisocyanate is, for example, 25 parts by mass or more, preferably 30 parts by mass or more, more preferably 32 parts by mass or more, based on 100 parts by mass of the total amount of the polyisocyanate component. It is 50 parts by mass or less, preferably 45 parts by mass or less, more preferably 40 parts by mass or less, and further preferably 35 parts by mass or less.

Further, the content ratio of the isocyanate group-terminated prepolymer is the above-mentioned balance, and is, for example, 50 parts by mass or more, preferably 55 parts by mass or more, and more preferably 60 parts by mass with respect to 100 parts by mass of the total amount of the polyisocyanate component. It is 5 parts by mass or more, more preferably 65 parts by mass or more, for example, 75 parts by mass or less, preferably 70 parts by mass or less, and more preferably 68 parts by mass or less.

The content of unreacted diphenylmethane diisocyanate in the polyisocyanate component (including the reaction product in the production of the isocyanate group-terminated prepolymer) can be determined, for example, by HPLC measurement, and the above-mentioned isocyanate group-terminated prepolymer can be obtained. It can also be calculated as a theoretical concentration from the charge ratio of diphenylmethane diisocyanate and polyol in the production of prepolymer.

Further, the content of unreacted diphenylmethane diisocyanate is adjusted so as to be within a predetermined range with respect to the two-component curable solvent-free adhesive (that is, the total of the polyisocyanate component and the polyol component) described later.

More specifically, the content ratio of unreacted diphenylmethane diisocyanate is 100 parts by mass of a two-component curable solvent-free adhesive, which will be described later, from the viewpoint of suppressing appearance defects during low-temperature curing and improving the content resistance. With respect to 20 parts by mass or more, preferably 21 parts by mass or more, more preferably 22 parts by mass or more, and 30 parts by mass or less, preferably 28 parts by mass or less, more preferably 25 parts by mass or less. is there.

When the content ratio of unreacted diphenylmethane diisocyanate is within the above range, excellent coating appearance and low-temperature curability can be obtained.

The content ratio of unreacted diphenylmethane diisocyanate in the two-component curable solvent-free adhesive can be determined by, for example, HPLC measurement, and is calculated as a theoretical concentration from the compounding ratio of the polyisocyanate component and the polyol component. You can also do it.

The isocyanate group equivalent of the polyisocyanate component is, for example, more than 210, preferably 230 or more, and for example, 320 or less, preferably 300 or less, preferably 250 or less.

The isocyanate group equivalent is synonymous with the amine equivalent, and can be determined by the method A or method B of JIS K 1603-1 (2007).

The polyol component contains a polyester polyol as an essential component.

Examples of the polyester polyol include the above-mentioned polyester polyol, and specific examples thereof include a polycondensate of a low molecular weight polyol and a polybasic acid, a plant-derived polyester polyol, and a lactone-based polyester polyol.

The polyester polyol preferably includes a polycondensate of a low molecular weight polyol and a polybasic acid.

Examples of the low molecular weight polyol include the above-mentioned low molecular weight polyol, preferably a dihydric alcohol, and more preferably diethylene glycol.

Examples of the polybasic acid include the above-mentioned polybasic acids, preferably saturated aliphatic dicarboxylic acids and aromatic dicarboxylic acids, and more preferably adipic acid and phthalic acid.

The method for polycondensing the low molecular weight polyol and the polybasic acid is not particularly limited, and a known method is adopted.

The number average molecular weight of the polyester polyol is 1000 or less, preferably 950 or less, more preferably 900 or less, still more preferably 850 or less, from the viewpoint of adjusting the viscosity in a solvent-free state. Further, for example, it is more than 300, preferably more than 400, more preferably 500 or more, still more preferably 600 or more.

The number average molecular weight of the polyester polyol can be measured by the GPC method, and can be calculated from the hydroxyl value and the average number of functional groups (the same applies hereinafter).

Preferably, the number average molecular weight of the polyester polyol is calculated from the hydroxyl value and the average number of functional groups by the following formula.

Number average molecular weight = hydroxyl value x average number of functional groups The hydroxyl value can be obtained from an acetylation method or a phthalation method based on the A method or the B method of JIS K 1557-1 (2007). In addition, the average number of functional groups can be obtained from the charging ratio of each component constituting the polyester polyol and the number of functional groups.

In addition, the polyol component may contain other high molecular weight polyols (high molecular weight polyols other than polyester polyols) and low molecular weight polyols as optional components.

Examples of other high molecular weight polyols include the above-mentioned polyether polyol and the above-mentioned polycarbonate polyol. Other high molecular weight polyols can be used alone or in combination of two or more.

Preferably, no other high molecular weight polyol is contained in the polyol component. In other words, the polyol component preferably contains the above-mentioned polyester polyol alone as a high molecular weight polyol.

Examples of the low molecular weight polyol include the above-mentioned low molecular weight polyol. The low molecular weight polyol can be used alone or in combination of two or more.

The low molecular weight polyol preferably includes a trihydric or higher alcohol. The trihydric or higher alcohol is a crosslinkable polyol, in other words, the polyol component preferably contains a crosslinkable polyol.

If the polyol component contains a trihydric or higher alcohol, a two-component curable solvent-free adhesive having excellent low-temperature curability and content resistance can be obtained.

More specifically, as trihydric or higher alcohols, for example, trihydric alcohols such as glycerin, trimethylolpropane and triisopropanolamine, for example, tetrahydric alcohols such as tetramethylolmethane (pentaerythritol) and diglycerin, for example, Pentahydric alcohols such as xylitol, eg, hexahydric alcohols such as sorbitol, mannitol, alitol, iditol, darsitol, altritor, inositol, dipentaerythritol, eg, 7-hydric alcohols such as persetol, eg, octavalent such as sucrose. Alcohol and the like can be mentioned.

These trihydric or higher alcohols can be used alone or in combination of two or more.

Examples of the trihydric or higher alcohol preferably include trihydric alcohol, more preferably glycerin and trimethylolpropane, and further preferably trimethylolpropane from the viewpoint of boil resistance.

The content ratio of the trivalent or higher alcohol is, for example, 0.1 part by mass or more, preferably 0.5 part by mass or more, preferably 10 parts by mass or less, based on 100 parts by mass of the total amount of the polyol component. Is 5 parts by mass or less, more preferably 3 or less.

Further, the two-component curable solvent-free adhesive contains phosphoric acid.

More specifically, in a two-component curable solvent-free adhesive, either one or both of the polyisocyanate component and the polyol component contains phosphoric acid. Preferably, the polyol component contains phosphoric acid.

Examples of phosphoric acid include hypophosphorous acid, phosphorous acid, orthophosphoric acid, and hypophosphoric acid. In addition, examples of phosphoric acid include condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid.

Further, as the phosphoric acid, for example, a phosphate such as sodium or potassium or a condensed phosphate, for example, monomethyl orthophosphoric acid, monoethyl orthophosphate, monopropyl orthophosphate, monobutyl orthophosphate, mono-2-ethylhexyl orthophosphoric acid, Monoesters such as monophenyl orthophosphate, monomethyl phosphite, monoethyl phosphite, monopropyl phosphite, monobutyl phosphite, mono-2-ethylhexyl phosphite, monophenyl phosphite, for example, orthophosphate. Di-2-ethylhexyl, diphenyl orthophosphate, trimethyl orthophosphate, triethyl orthophosphate, tripropyl orthophosphate, tributyl orthophosphate, tri-2-ethylhexyl orthophosphate, triphenyl orthophosphate, dimethyl phosphite, diethyl phosphite, Dipropyl phosphite, dibutyl phosphite, di-2-ethylhexyl phosphite, diphenyl phosphite, trimethyl phosphite, triethyl phosphite, tripropyl phosphite, tributyl phosphite, tri-phosphate phosphite Examples thereof include di and triesters such as 2-ethylhexyl and triphenyl phosphite, and mono, di and triesters obtained from condensed phosphoric acid and alcohols.

These phosphoric acids can be used alone or in combination of two or more.

Phosphoric acid is preferably orthophosphoric acid.

The content ratio of phosphoric acid is 0.003 with respect to 100 parts by mass of the total amount of the two-component curable solvent-free adhesive from the viewpoint of suppressing poor appearance at low temperature curing and improving the content resistance. It is 0 parts by mass or more, preferably 0.005 parts by mass or more, more preferably 0.010 parts by mass or more, further preferably 0.012 parts by mass or more, and particularly preferably 0.014 parts by mass or more. It is .030 parts by mass or less, preferably 0.025 parts by mass or less, and more preferably 0.020 parts by mass or less.

When phosphoric acid is contained in the polyol component, phosphoric acid is, for example, 0.005 part by mass or more, preferably 0.010 part by mass or more, based on 100 parts by mass of the total amount of the polyol component. It is preferably 0.030 parts by mass or more, more preferably 0.040 parts by mass or more, and for example, 0.090 parts by mass or less, preferably 0.070 parts by mass or less.

If the two-component curable solvent-free adhesive contains phosphoric acid in the above ratio, poor appearance can be suppressed, and low-temperature curability and content resistance can be improved.

Further, the two-component curable solvent-free adhesive preferably contains a silane coupling agent.

More specifically, in a two-component curable solvent-free adhesive, either one or both of the polyisocyanate component and the polyol component contains a silane coupling agent. Preferably, the polyol component contains a silane coupling agent.

The silane coupling agent is, for example, structural formula R-Si≡ (X) ₃ or R-Si≡ (R') (X) ₂ (in the formula, R is a vinyl group, an epoxy group, an amino group, an imino group, It represents an organic group having an isocyanate group or a mercapto group, R'represents a lower alkyl group having 1 to 4 carbon atoms, and X represents a methoxy group, an ethoxy group or a chloro atom).

Specific examples of the silane coupling agent include chlorosilanes such as vinyltricrolsilane, for example, γ-glycidoxypropyltrimethoxysilane (also known as 3- (trimethoxysilyl) propylglycidyl ether) and γ-glycid. Epoxysilanes such as xypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, di (γ-glycidoxypropyl) dimethoxysilane, for example N-β- (aminoethyl) -γ- Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-propylmethyldimethoxysilane, n- (dimethoxymethylsilylpropyl) ethylenediamine, n- (triethoxysilylpropyl) ethylenediamine, Aminosilanes such as N-phenyl-γ-aminopropyltrimethoxysilanes, such as vinylsilanes such as vinyltriethoxysilanes, such as γ-isocyanatopropyltrimethoxysilanes, isocyanatosilanes such as γ-isocyanatopropyltriethoxysilanes, etc. Can be mentioned.

The silane coupling agent can be used alone or in combination of two or more.

The silane coupling agent preferably includes epoxysilane and aminosilane, more preferably epoxysilane, and particularly preferably γ-glycidoxypropyltrimethoxysilane (also known as 3- (trimethoxysilyl)). Propylglycidyl ether).

The content ratio of the silane coupling agent is, for example, 0.1 part by mass or more, preferably 0.15 part by mass or more, more preferably 0.1 part by mass or more, based on 100 parts by mass of the total amount of the two-component curable solvent-free adhesive. It is 0.2 parts by mass or more, for example, 15 parts by mass or less, preferably 10 parts by mass or less, more preferably 5.0 parts by mass or less, still more preferably 1.0 part by mass or less, still more preferably. It is 0.5 parts by mass or less, more preferably 0.4 parts by mass or less, and particularly preferably 0.3 parts by mass or less.

When the silane coupling agent is contained in the polyol component, the silane coupling agent is, for example, 0.3 parts by mass or more, preferably 0.5 parts by mass, based on 100 parts by mass of the total amount of the polyol component. More than parts, for example, 40 parts by mass or less, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5 parts by mass or less, still more preferably 1.5 parts by mass or less, in particular. Preferably, it is 1.0 part by mass or less.

If the two-component curable solvent-free adhesive contains the silane coupling agent in the above ratio, the content resistance can be further improved, and further, excellent boil resistance can be obtained. In particular, if both the content ratio of the silane coupling agent and the content ratio of phosphoric acid are adjusted to the above ranges, it is possible to improve the content resistance to citrus fruit juice (orange juice, etc.). it can.

Further, one or both of the polyisocyanate component and the polyol component may be used, for example, as an antifoaming agent, an epoxy resin, a catalyst, a coatability improver, a leveling agent, and a stabilizer (antioxidant,). Additives such as UV absorbers), plasticizers, surfactants, pigments, fillers, organic or inorganic fine particles, and antifungal agents can be appropriately added.

The blending amount of the additive is appropriately determined depending on the purpose and use thereof.

In the two-component curable solvent-free adhesive, the above-mentioned polyol component (main agent) and the above-mentioned polyisocyanate component (curing agent) are prepared and blended at the time of use.

From the viewpoint of improving the adhesiveness, the compounding ratio of the polyisocyanate component and the polyol component is, for example, 0.5 or more as the equivalent ratio (NCO / OH) of the isocyanate group of the polyisocyanate component to the hydroxyl group of the polyol component. It is preferably 0.6 or more, for example, 5 or less, preferably 3 or less.

The mixing ratio of the polyisocyanate component and the polyol component is, for example, 30 parts by mass or more, preferably 40 parts by mass or more, and for example, 100 parts by mass or less, with respect to 100 parts by mass of the polyisocyanate component. It is preferably 80 parts by mass or less, and more preferably 70 parts by mass or less.

Then, the two-component curable solvent-free adhesive is formulated as described above and then applied to the adherend by a known laminator.

Examples of the adherend include a plastic film and a barrier layer.

That is, the two-component curable solvent-free adhesive is used as a laminating adhesive for producing a composite film by laminating a plastic film or a barrier layer.

Preferably, a two-component curable solventless adhesive is used to attach the plastic film to the barrier film.

Examples of the plastic film include olefin-based polymers (for example, polyethylene, polypropylene, etc.), polyester-based polymers (for example, polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate, polyalkylene naphthalates, and their polyalkylene allylates. Unit-based copolyester, etc.), polyamide-based polymer (for example, nylon 6, nylon 66, etc.), vinyl-based polymer (for example, polyvinyl chloride, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol) Examples thereof include a film made of a polymer such as (polymer, etc.).

Examples of the plastic film include a film made of an olefin polymer, and more preferably a polyethylene film and a polypropire film.

Further, as the plastic film, either an unstretched film (unstretched polyethylene, unstretched polypropylene, etc.) or a uniaxially or biaxially stretched film (biaxially stretched polypropylene, biaxially stretched polyalkylene terephthalate, nylon, etc.) is used. Can be done.

As the plastic film, an unstretched film is preferable, and an unstretched polyethylene film and an unstretched polypropylene film are more preferable.

Further, the plastic film can be prepared as various coextruded films or a composite film in which plastic films are attached in advance.

The thickness of the plastic film is not particularly limited, but is, for example, 5 μm or more, preferably 10 μm or more, and for example, 200 μm or less, preferably 100 μm or less.

The barrier film is a film having a barrier property against gas or liquid, and examples thereof include a metal film and an inorganic vapor-deposited film.

Examples of the metal film include a metal foil made of aluminum, stainless steel, iron, copper, lead and the like. The metal film preferably includes a metal foil made of aluminum.

The thickness of the metal film is, for example, 5 μm or more, preferably 10 μm or more, for example, 100 μm or less, preferably 20 μm or less, and more preferably 15 μm or less.

The inorganic vapor-deposited film is a plastic film in which an inorganic layer is vapor-deposited on at least one surface.

The inorganic layer can be formed by vapor deposition, sputtering, a sol-gel method, or the like. The inorganic layer is made of, for example, a simple substance such as titanium, aluminum, or silicon, or an inorganic compound (oxide or the like) containing an element thereof. Preferably, a vapor-deposited film obtained by depositing alumina alone, silica alone, or both alumina and silica is used.

Further, in the inorganic vapor-deposited film, examples of the plastic film on which the inorganic layer is vapor-deposited include the same as those described above. Specifically, olefin-based polymer, polyester-based polymer, polyamide-based polymer, and vinyl-based heavy weight. Examples thereof include a film made of a polymer such as a coalescence. As the plastic film on which the inorganic layer is vapor-deposited, a film made of a polyester-based polymer is preferable, and a film made of polyethylene terephthalate is more preferable.

The inorganic vapor-deposited film is formed by a combination of the above-mentioned inorganic layer and the above-mentioned plastic film. The inorganic vapor-deposited film preferably includes a polyethylene terephthalate film on which alumina is vapor-deposited.

As the barrier film, an inorganic vapor-deposited film is preferable.

When an inorganic vapor-deposited film is used as the barrier film, the surface to be attached to the plastic film may be either one surface (inorganic layer) or the other surface (plastic film) of the inorganic vapor-deposited film. Preferably, the inorganic layer in the inorganic vapor-deposited film is attached to the plastic film.

In addition, the plastic film and the barrier film can have an overcoat layer, if necessary. Further, the plastic film and the barrier film may be subjected to various treatments such as corona discharge treatment and primer treatment, if necessary.

Then, a laminated film is obtained by adhering these films (plastic film, barrier film, etc.) via an adhesive layer made of the above-mentioned two-component curable solvent-free adhesive.

More specifically, in the production of a laminated film, first, an adhesive containing a polyisocyanate component and a polyol component is applied to the surface of either a plastic film or a barrier film.

Next, the coated surface is attached to the surface of the other barrier film or plastic film, and then cured and cured at room temperature or under heating.

As the laminated film, a barrier film and a plastic film may be attached (primary laminate) to prepare a primary laminated composite film, and further, another may be formed on at least one surface of the primary laminated composite film. It is also possible to attach a plastic film (secondary laminating) to produce a secondary laminating composite film.

In the primary laminating, usually either one of the barrier film or the plastic film is sent out from the sending roll, the other is attached, and the winding is wound on the winding roll, and if necessary, heating and curing (for example, 25 to 60). Curing at ℃).

In the secondary laminating, usually, the primary laminating composite film is sent out from the winding roll, another plastic film is attached to the winding roll, the film is wound on the winding roll, and if necessary, it is heated and cured.

In the production of the secondary laminate composite film, the two-component curable solvent-free adhesive of the present invention may be used in both the primary laminate and the secondary laminate, or the primary laminate and the secondary laminate may be prepared. It is also possible to use the two-component curable solvent-free adhesive of the present invention in one of them and the other adhesive in the other.

The laminating temperature (coating temperature) is, for example, 35 ° C. or higher, preferably 40 ° C. or higher. If it can be laminated, there is no upper limit of temperature, but it is usually 100 ° C. or lower, preferably 90 ° C. or lower, and more preferably 85 ° C. or lower.

Further, at the time of laminating (coating), for example, the adhesive can be heated to adjust the viscosity to an appropriate level. When heating, the temperature is, for example, 35 to 100 ° C., preferably 35 to 90 ° C., more preferably 40 to 80 ° C. The viscosity of the adhesive in that case is, for example, 4000 to 8000, preferably 5000 to 7500 at 50 ° C. If the heating is set to 100 ° C. or lower, the reaction between the polyisocyanate component and the polyol component can be suppressed before coating, so that excessive thickening can be prevented and good workability can be ensured.

The coating amount of two-component curing type non solvent-based adhesives, in each laminating step, for example, 0.5 to 5 g / ^{m 2,} preferably, 1 to 5 g / ^{m 2,} more preferably, 1.5-4 It is .5 g / m ² .

Further, as the laminating device in which the two-component curing type solvent-free adhesive is used, either a forward transfer type coating device or a reverse transfer type coating device (reverse coater) can be used.

Such a two-component curable solvent-free adhesive contains a polyisocyanate component and a polyol component, and further contains unreacted diphenylmethane diisocyanate and phosphoric acid in a predetermined ratio.

Therefore, the above-mentioned two-component curable solvent-free adhesive has excellent production efficiency, has an appropriate pot life, can suppress appearance defects, has excellent low-temperature curability, and has excellent content resistance. An excellent laminated film can be produced.

Therefore, according to the two-component curable solvent-free adhesive of the present invention, laminated films in various industrial fields such as foods, beverages, pharmaceuticals and quasi-drugs can be suitably obtained.

Further, the present invention relates to a laminate film (primary laminate film, secondary laminate film, etc.) obtained by using the above-mentioned two-component curable solvent-free adhesive, that is, the above-mentioned two-component curable solvent-free adhesive. Includes a laminate film with an adhesive layer consisting of.

Since such a laminated film contains an adhesive layer made of the above-mentioned two-component curable solvent-free adhesive, it is excellent in production efficiency, and is also excellent in appearance and content resistance.

Next, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition, "part" and "%" are based on mass unless otherwise specified. In addition, specific numerical values such as the compounding ratio (content ratio), physical property values, and parameters used in the following description are the compounding ratios corresponding to those described in the above-mentioned "Form for carrying out the invention". Substitute the upper limit value (value defined as "less than or equal to" or "less than") or the lower limit value (value defined as "greater than or equal to" or "excess") such as content ratio), physical property value, and parameters. be able to.

<Polyisocyanate component>
Production Example 1 (Production of Polyesterdiol A)
614 g of adipic acid, 477 g of neopentyl glycol, and 87 g of propylene glycol were charged into a reactor and subjected to an esterification reaction at 160 to 220 ° C. under a nitrogen stream.

Then, after distilling out the predetermined water, 0.01 g of tin octylate was added as a catalyst, and the esterification reaction was carried out at 180 to 220 ° C. under a nitrogen stream to obtain polyesterdiol A.

The polyester diol A had an average number of functional groups of 2.0, a hydroxyl group equivalent of 400, and a number average molecular weight of 800.

Production Example 2 (Production of polyisocyanate component A-1)
Polyesterdiol A 110g, polypropylene glycol (trade name D-1000, molecular weight 1000, manufactured by Mitsui Chemicals SKC Polyurethane (same below)) 320g, and luplanate MI (liquid diphenylmethane diisocyanate (MDI), manufactured by BASF (same below)) 571g Was charged into a reactor and subjected to a urethanization reaction at 70 to 80 ° C. under a nitrogen stream to obtain a polyisocyanate component A-1.

The unreacted diphenylmethane diisocyanate concentration (theoretical concentration) in the polyisocyanate component A-1 was 34.3%, and the isocyanate group equivalent (based on JIS K 1603-1 (2007) A method (the same applies hereinafter)) was 274. It was.

Production Example 3 (Production of polyisocyanate component A-2)
116 g of polyester diol A, 339 g of D-1000 (polypropylene glycol, molecular weight 1000), and 544 g of ruplanate MI (diphenylmethane diisocyanate) were charged into a reactor and subjected to a urethanization reaction at 70 to 80 ° C. under a nitrogen stream to cause a polyisocyanate component A-2. Got

The unreacted diphenylmethane diisocyanate concentration (theoretical concentration) in the polyisocyanate component A-2 was 30.3%, and the isocyanate group equivalent was 295.

Production Example 4 (Production of polyisocyanate component A-3)
94 g of polyester diol A, 273 g of D-1000 (polypropylene glycol, molecular weight 1000), and 633 g of ruplanate MI (diphenylmethane diisocyanate) were charged into a reactor and subjected to a urethanization reaction at 70 to 80 ° C. under a nitrogen stream to cause a polyisocyanate component A-3. Got

The unreacted diphenylmethane diisocyanate concentration (theoretical concentration) in the polyisocyanate component A-3 was 43.9%, and the isocyanate group equivalent was 233.

Production Example 5 (Production of polyisocyanate component A-4)
124 g of polyester diol A, 361 g of D-1000 (polypropylene glycol, molecular weight 1000), and 515 g of ruplanate MI (diphenylmethane diisocyanate) were charged into a reactor and subjected to a urethanization reaction at 70 to 80 ° C. under a nitrogen stream to cause a polyisocyanate component A-4. Got

The unreacted diphenylmethane diisocyanate concentration (theoretical concentration) in the polyisocyanate component A-4 was 25.8%, and the isocyanate group equivalent was 323.

Production Example 6 (Production of polyisocyanate component A-5)
82 g of polyester diol A, 238 g of D-1000 (polypropylene glycol, molecular weight 1000), and 680 g of ruplanate MI (diphenylmethane diisocyanate) were charged into a reactor and subjected to a urethanization reaction at 70 to 80 ° C. under a nitrogen stream to cause a polyisocyanate component A-5. Got

The unreacted diphenylmethane diisocyanate concentration (theoretical concentration) in the polyisocyanate component A-5 was 51.0%, and the isocyanate group equivalent was 210.

Table 1 shows the compounding formulation of each polyisocyanate component and the equivalent ratio R (NCO / OH) of the isocyanate group in the diphenylmethane diisocyanate to the hydroxyl group in the polyol.

Production Example 7 (Production of polyisocyanate component A-6)
124 g of polyester diol A, 361 g of D-1000 (polypropylene glycol, molecular weight 1000), and 515 g of TDI (toluene diisocyanate) were charged into a reactor and subjected to a urethanization reaction at 70 to 80 ° C. under a nitrogen stream. Then, the unreacted toluene diisocyanate was removed upstream of the thin film to obtain a polyisocyanate component A-6.

The unreacted toluene diisocyanate (TDI) concentration (theoretical concentration) in the polyisocyanate component A-6 was 0.1%, and the isocyanate group equivalent was 574.

Table 1 shows the compounding formulation of each polyisocyanate component and the equivalent ratio R (NCO / OH) of the isocyanate group in the diphenylmethane diisocyanate to the hydroxyl group in the polyol.

<Polycarbonate component>
Production Example 8 (Production of Polyesterdiol B)
221 g of phthalic acid, 327 g of adipic acid, and 587 g of diethylene glycol were charged into a reactor and subjected to an esterification reaction at 160 to 220 ° C. under a nitrogen stream.

Then, after distilling out the predetermined water, 0.01 g of tin octylate was added as a catalyst, and the esterification reaction was carried out at 180 to 220 ° C. under a nitrogen stream to obtain polyesterdiol B.

The average number of functional groups of the polyester diol B was 2.0, the hydroxyl equivalent was 375, and the number average molecular weight was 700.

Production Example 9 (Production of polyol component B-1)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 9 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.45 g of orthophosphoric acid (hereinafter, simply referred to as phosphoric acid) are added, and the mixture is stirred and mixed for 30 minutes. The polyol component B-1 was obtained.

Production Example 10 (Production of polyol component B-2)
980 g of polyester diol B and 10 g of glycerin were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 9 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.45 g of orthophosphoric acid (hereinafter, simply referred to as phosphoric acid) are added, and the mixture is stirred and mixed for 30 minutes. The polyol component B-2 was obtained.

Production Example 11 (Production of polyol component B-3)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 4.5 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.45 g of phosphoric acid are added, and the mixture is stirred and mixed for 30 minutes to obtain polyol component B-3. Got

Production Example 12 (Production of polyol component B-4)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 97.9 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.49 g of phosphoric acid are added, and the mixture is stirred and mixed for 30 minutes to add polyol component B-4. Obtained.

Production Example 13 (Production of polyol component B-5)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 9 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.85 g of phosphoric acid are added, and the mixture is stirred and mixed for 30 minutes to obtain polyol component B-5. It was.

Production Example 14 (Production of polyol component B-6)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 9 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.30 g of phosphoric acid are added, and the mixture is stirred and mixed for 30 minutes to obtain polyol component B-6. It was.

Production Example 15 (Production of polyol component B-7)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 9 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.10 g of phosphoric acid are added, and the mixture is stirred and mixed for 30 minutes to obtain polyol component B-6. It was.

Production Example 16 (Production of polyol component B-8)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 9 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 1.0 g of phosphoric acid are added, and the mixture is stirred and mixed for 30 minutes to obtain polyol component B-8. It was.

Production Example 17 (Production of polyol component B-9)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 9 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.05 g of phosphoric acid are added, and the mixture is stirred and mixed for 30 minutes to obtain polyol component B-9. It was.

Production Example 18 (Production of polyol component B-10)
980 g of polyester diol B and 10 g of trimethylolpropane were charged into a reactor, and the mixture was stirred and mixed at 80 ° C. for 60 minutes under a nitrogen stream.

Then, the temperature is lowered to 60 ° C., 533 g of 3- (trimethoxysilyl) propylglycidyl ether (silane coupling agent) and 0.69 g of orthophosphoric acid (hereinafter, simply referred to as phosphoric acid) are added, and the mixture is stirred and mixed for 30 minutes. The polyol component B-10 was obtained.

The formulation of each polyol component is shown in Table 2.

<Two-component curable solvent-free adhesive>
By combining each of the polyisocyanate components and each polyol component obtained as described above in a predetermined number of parts (parts by mass), a two-component curable solvent-free adhesive of each Example and each Comparative Example was prepared.

Further, the unreacted diphenylmethane diisocyanate (MDI) concentration, the phosphoric acid concentration, and the silane coupling agent concentration in the obtained two-component curable solvent-free adhesive were calculated based on the blending ratio. Further, these two-component curable solvent-free adhesives were used to measure the change in the viscosity of the compounding liquid over time, and the results are shown in Tables 3 to 6.

Evaluation Using each two-component curable solvent-free adhesive, composite films were prepared by the methods described below, and then the physical characteristics of each composite film were evaluated.

The results are shown in Tables 3 to 6.

<Preparation of composite film A>
Two liquids by mixing 10 parts by weight of Takelac A-310 (polyolethane component, manufactured by Mitsui Chemicals) and 1 part by weight of Takenate A-3 (polyisocyanate component, manufactured by Mitsui Chemicals) and diluting with ethyl acetate. A mold organic solvent-based adhesive was prepared.

Then, a polyethylene terephthalate film (thickness 12 μm, Lumirror P60, manufactured by Toray Film Processing Co., Ltd.) and an aluminum foil (thickness 9 μm, manufactured by Toyo Aluminum K.K.) are first laminated with a two-component organic solvent-based adhesive. A laminated composite film was produced.

Next, a solvent-free laminator (manufactured by Okazaki Kikai Kogyo Co., Ltd., non-sol laminator TNS-400-200) was used on the surface of the aluminum foil of the primary laminated composite film (A), and two liquids of each Example and each Comparative Example were used. A curable solvent-free adhesive was applied (coating temperature 50 ° C., coating amount about 2.0 g / m ² , coating speed 150 m / min).

Then, an unstretched polyethylene film (thickness 40 μm, linear low-density polyethylene film TUX-HC (manufactured by Mitsui Chemicals Tocello Co., Ltd.)) was laminated on the coated surface to prepare a laminated composite film A. Then, the laminated composite film A was cured at 40 ° C. for 2 days to cure the two-component curable solvent-free adhesive.

<Evaluation: Orange juice resistance test>
Using the laminated composite film A obtained as described above, a bag having a size of 6.5 × 17.5 cm was produced. The bag was prepared by heat sealing, and the unstretched polyethylene film was on the inside and the polyethylene terephthalate film was on the outside.

The bag was filled with ponjuice (100% fruit juice) as the content. The bag was stored in a thermostat at 50 ° C. for 2 weeks, then the contents were taken out, and the adhesive strength between the aluminum foil and the unstretched polyethylene film was adjusted to a test piece width of 15 mm and a tensile speed of 300 mm / min in an environment of 25 ° C. It was measured by a T-type peeling test. The results are shown in Tables 3 to 6.

Tables 3 to 6 also show the state of the laminated composite film A after the T-type peeling test. Specifically, "PE Nobi" indicates that the unstretched polyethylene film was stretched after the test, and "AL / Ad" indicates that the unstretched polyethylene film was peeled off between the aluminum foil and the adhesive layer.

Similarly, the heat seal strength was measured. The results are shown in Tables 3 to 6.

Tables 3 to 6 also show the state of the laminated composite film A after the heat seal strength test. Specifically, "Film gilet" means that the unstretched polyethylene film was cut after the test, and "△ peeling" means that the unstretched polyethylene film was peeled off from the adhesive layer and floated like a ridge. Show that.

<Preparation of composite film B>
Aluminum-deposited polyethylene terephthalate (PET) film (thickness 12 μm, VMPET, manufactured by Toray Film Processing Co., Ltd.) using a solvent-free laminator (manufactured by Okazaki Kikai Kogyo Co., Ltd., non-sol laminator TNS-400-200) on the aluminum vapor deposition surface. The two-component curable solvent-free adhesives of Examples and Comparative Examples were applied (coating temperature 50 ° C., coating amount about 1.5 g / m ² , coating speed 150 m / min). Then, a polyethylene terephthalate film (thickness 12 μm, E-5102, manufactured by Toray Film Processing Co., Ltd.) was laminated on the coated surface to prepare a primary laminated composite film (B).

Next, a solvent-free laminator (manufactured by Okazaki Kikai Kogyo Co., Ltd., non-sol laminator TNS-400-200) was used on the back surface of the primary laminated composite film (B) E-5102, and the second of each example and each comparative example. A liquid-curable solvent-free adhesive was applied (coating temperature 50 ° C., coating amount about 2.0 g / m2, coating speed 150 m / min).

Then, an unstretched polyethylene film (thickness 40 μm, linear low-density polyethylene film TUX-HC (manufactured by Mitsui Chemicals Tohcello Co., Ltd.)) was bonded to the coated surface to prepare a laminated composite film B. Then, the laminated composite film B was cured at 40 ° C. for 2 days to cure the two-component curable solvent-free adhesive.

<Evaluation: Content resistance (alkali) resistance test>
Using the laminated composite film B obtained as described above, a bag having a size of 6.5 × 17.5 cm was produced. The bag was prepared by heat sealing, and the unstretched polyethylene film was on the inside and the aluminum-deposited polyethylene terephthalate film was on the outside.

The bag was filled with Kao Attack (weakly alkaline liquid detergent) as the contents. After storing the bag in a thermostat at 50 ° C. for 2 weeks, the contents were taken out, and the adhesive strength between the polyethylene terephthalate film (E-5102) and the unstretched polyethylene film was adjusted to a test piece width of 15 mm under an environment of 25 ° C. The tensile speed was 300 mm / min, and the measurement was performed by a T-type peeling test. The results are shown in Tables 3 to 6.

Similarly, the heat seal strength was measured. The results are shown in Tables 3 to 6.

Tables 3 to 6 also show the state of the laminated composite film B after the T-type peeling test. Specifically, "PET surface layer peeling" means that the adhesive layer and the unstretched polyethylene film were peeled off on the surface layer of the polyethylene terephthalate film (E-5102).

Similarly, the heat seal strength was measured. The results are shown in Tables 3 to 6.

Tables 3 to 6 also show the state of the laminated composite film B after the heat seal strength test. Specifically, "Film gilet" indicates that the unstretched polyethylene film was cut after the test.

<Evaluation: Coating appearance>
The laminated appearance of the primary laminated composite film (B) obtained as described above was observed and evaluated according to the following criteria.
◯: No air bubbles and / or yuzu skin were confirmed, and the appearance was good.
Δ: Very few bubbles were confirmed.
X: Significant bubbles and / or citron skin were confirmed.

<Preparation of composite film C>
Each example and each comparison using a solvent-free laminator (manufactured by Okazaki Kikai Kogyo Co., Ltd., non-sol laminator TNS-400-200) on the inner surface of a nylon (NY) film (thickness 15 μm, emblem ONBC, manufactured by Unitica Co., Ltd.). The example two-component curable solvent-free adhesive was applied (coating temperature 50 ° C., coating amount about 1.5 g / m ² , coating speed 150 m / min). Then, an unstretched polyethylene film (thickness 40 μm, linear low-density polyethylene film TUX-HC (manufactured by Mitsui Chemicals Tocello Co., Ltd.)) was laminated on the coated surface to prepare a laminated composite film C. Then, the laminated composite film C was cured at 40 ° C. for 2 days to cure the two-component curable solvent-free adhesive.

<Evaluation: Content resistance (boil) resistance test>
Using the laminated composite film C obtained as described above, a bag having a size of 6.5 × 17.5 cm was produced. The bag was prepared by heat sealing, and the unstretched polyethylene film was on the inside and the nylon film was on the outside.

The bag was filled with water / oil (volume ratio 9/1) as the contents. The bag was boiled in hot water at 100 ° C. for 30 minutes, then the contents were taken out, and the adhesive strength between the nylon / unstretched polyethylene film was adjusted to a test piece width of 15 mm and a tensile speed of 300 mm / min in an environment of 25 ° C. It was measured by a T-type peeling test. The results are shown in Tables 3 to 6.

Similarly, the heat seal strength was measured. The results are shown in Tables 3 to 6.

Tables 3 to 6 also show the state of the laminated composite film C after the T-type peeling test. Specifically, "PE cut" indicates that the unstretched polyethylene film was cut after the test, and "NY / ad" means that the nylon film and the adhesive interface were peeled off after the test. ..

Similarly, the heat seal strength was measured. The results are shown in Tables 3 to 6.

Tables 3 to 6 also show the state of the laminated composite film C after the heat seal strength test. Specifically, "PE / PE" indicates that the unstretched polyethylene films were peeled off after the test.

<Evaluation: Coating appearance>
The laminated appearance of the primary laminated composite film (C) obtained as described above was observed and evaluated according to the following criteria.
◯: No air bubbles and / or yuzu skin were confirmed, and the appearance was good.
Δ: Very few bubbles were confirmed.
X: Significant bubbles and / or citron skin were confirmed.

The above invention has been provided as an exemplary embodiment of the present invention, but this is merely an example and should not be construed in a limited manner. Modifications of the present invention that are apparent to those skilled in the art are included in the claims below.

The two-component curable solvent-free adhesive and laminate film of the present invention can be suitably used in various industrial fields such as foods, beverages, pharmaceuticals and quasi-drugs.

Claims (4)

A two-component curable solvent-free adhesive containing a polyisocyanate component and a polyol component.
The polyisocyanate component is
It contains an isocyanate group-terminated prepolymer, which is a reaction product of diphenylmethane diisocyanate and a polyol, and unreacted diphenylmethane diisocyanate.
The polyol component is
Contains a polyester polyol with a number average molecular weight of 1000 or less,
The amount of unreacted diphenylmethane diisocyanate is 20 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the two-component curing type solventless adhesive.
A two-component curable solvent-free adhesive containing 0.003 parts by mass or more and 0.030 parts by mass or less of phosphoric acid with respect to 100 parts by mass of the total amount of the two-component curable solvent-free adhesive. adhesive. The first aspect of claim 1, wherein the silane coupling agent is contained in an amount of 0.2 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the total amount of the two-component curable solvent-free adhesive. Two-component curable solvent-free adhesive. The two-component curable solvent-free adhesive according to claim 1, wherein the polyol component contains a trihydric or higher alcohol. A laminated film comprising an adhesive layer made of the two-component curable solvent-free adhesive according to any one of claims 1 to 3.