KR100586132B1 - Laminate Adhesives - Google Patents

Abstract

The present invention provides a laminate adhesive having good adhesion to various films and metal foils, and relates to a laminate adhesive containing a resin having a dynamic wettability of 0.20 mN or more with respect to a film substrate. Furthermore, this invention relates to the adhesive for laminates containing resin and polyisocyanate hardening | curing agent whose dynamic wettability with respect to a film base material is 0.20 mN or more.

Description

Adhesive for Laminates {ADHESIVES FOR LAMINATE}             

BRIEF DESCRIPTION OF THE DRAWINGS It is a graph which shows the relationship of the dynamic wettability to the carboxyl group and various film base materials which were introduce | transduced into the polyurethane-type resin of one Embodiment of this invention.

The present invention relates to a laminate adhesive having good adhesion to all substrates such as plastic films, metal foils, metal deposition films, paper, and the like.

Adhesives for laminates in which various plastic films, metal foils, metal deposition films, paper, etc. are added together, and synthetic resins such as polyurethane resins, vinyl acetate resins, acrylic resins, polyamide resins and epoxy resins, and glues, casein and gelatin , Natural resins such as starch and cellulose are used. Among them, laminate adhesives using synthetic resins are the mainstream in terms of ease of molecular design and high productivity. Among them, polyurethane-based resins have excellent adhesive performance, durability, heat resistance, etc., and a wide application range in various films. Adhesives using are widely used.

One of the performance required for adhesives is to show good wettability to the film substrate. The application | coating process of an adhesive agent in the manufacturing process of a laminated film generally means the method of apply | coating an adhesive agent, moving a film at high speed. Thus, the "wetting" required for adhesives for laminates includes not only conventional "static wettability" but also "dynamic wettability" for films moving at high speed. Since the adhesive for laminates lacks such a viewpoint, the problem, such as the lack of adhesive strength and the external appearance of a laminate film, has arisen often by the poor application | coating of an adhesive agent.

In addition, the laminate film is produced by adding together films of different properties, such as aluminum foil and polyethylene film, polyethylene terephthalate film and polypropylene film, depending on the required performance such as gas barrier properties, heat sealability, and the like. There are many cases. However, good dynamic wettability is obtained for both different kinds of films, such as, for example, adhesion of polyethylene film and polyethylene terephthalate film, adhesion of polypropylene film and nylon film, adhesion of polyethylene terephthalate film and aluminum foil, and the like. There was no suitable thing as an adhesive agent for laminates shown.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve such a subject, the present inventors discovered that the said problem can be solved with the adhesive agent for laminates using resin whose dynamic wettability with respect to various film base materials is more than a specific value, and came to complete this invention.

That is, the present invention is an adhesive for laminates characterized by containing a resin having a dynamic wettability of 0.20 mN or more for a film substrate.

The present invention is also an adhesive for laminates comprising a resin having a dynamic wettability to a film base material of 0.20 mN or more and a polyisocyanate curing agent.

The resin used in the present invention is a resin having a dynamic wettability of 0.20 mN or more with respect to a film substrate measured under the conditions shown below by the Wilhelmy method, a polypropylene (hereinafter referred to as PP) film, polyethylene terephthalate (hereinafter A resin having a dynamic wettability of at least 0.2 mN for at least one film substrate selected from the group consisting of a film and an aluminum foil is preferred. Specifically, polyurethane resin, vinyl acetate resin, acrylic resin, polyamide resin, polyester resin, ionic polymer resin, epoxy resin, acrylic urethane resin, terminal carboxylated polyolefin and polydiene, synthetic rubber resin As such, a resin that is excellent in an ethyl acetate solution having a solid content of 25% as a measurement condition of dynamic wettability is more preferable. In the case where a resin having a dynamic wettability of less than 0.20 mN is used, the adhesive layer becomes nonuniform in the laminate film, which is likely to be a cause of problems in the manufacture of the laminate film, such as a lack of adhesive strength and generation of a laminated layer. In addition, the resin used in the present invention has sufficient adhesive strength even when the film of the same kind as well as different kinds of films are added together, and a resin having both a dynamic wettability of two kinds of film substrates is not less than 0.20 mN, Particularly preferred are resins having a dynamic wettability of three kinds of film substrates of at least 0.20 mN. In addition, not only one type of resin but two or more types of resin can be mixed and used for it.

Measurement Conditions of Dynamic Wetting

In view of its other performances required for adhesives for laminates, for example, heat resistance and flexibility, polyurethane-based resins are preferred, and among them, poly-containing carboxyl groups containing 0.01 to 10.0 mmol / g, especially 0.03 to 8.0 mmol / g. Urethane type resin is preferable. When content of carboxyl group of polyurethane resin is less than a lower limit, the adhesiveness in a metallic film base material tends to be inadequate. Moreover, when content of a carboxyl group exceeds an upper limit, a viscosity will become high too much and workability tends to deteriorate.

Most preferred polyurethane resins for use in the present invention are resins obtained by reacting (A) and (B) or (A) and (C) shown below:

(A) organic polyisocyanate.

(B) A low molecular polyol having a carboxyl group having a number average molecular weight of 300 or less, or a mixture of such low molecular polyols and other active hydrogen group-containing compounds.

(C) A carboxyl group-containing polylactone polyol using a low molecular polyol having a carboxyl group having a number average molecular weight of 300 or less as an initiator, or a mixture of such polylactone polyols and other active hydrogen group-containing compounds.

Examples of the organic polyisocyanate (A) include 2,4-trilene diisocyanate, 2,6-triylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, o-xylene diisocyanate, m-xylene diisocyanate , p-xylene diisocyanate, tetramethyl xylene diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4 '-Diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropanediisocyanate, 3,3'-dimethoxydiphenyl-4,4'-di Aromatic diisocyanates such as isocyanates, and tetramethylenediisocyde Aliphatic diisocyanates such as nates, hexamethylene diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, and ridine diisocyanate, and isophorone diisocyanate, hydrogenated diphenyl Alicyclic diisocyanates such as methane diisocyanate, hydrogenated triylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated tetramethyl xylene diisocyanate, cyclohexyl diisocyanate and mixtures of two or more thereof. Furthermore, modified polyisocyanates, such as adduct modified bodies, burette modified bodies, carbodiimide modified bodies, uretonimine modified bodies, uretodione modified bodies, and isocyanurate modified bodies, and polymethylene polyphenylene poly Any polymer such as isocyanate may also be used.

In addition, polyurethane-based resins obtained by reacting an aliphatic diisocyanate such as hexamethylene diisocyanate such as hexamethylene diisocyanate with a low molecular polyol containing a carboxyl group having a number average molecular weight of 300 or less tend to have a good balance of adhesion strength and adhesion. Therefore, it is suitable as an adhesive agent for laminations.

Moreover, as organic polyisocyanate (A), aromatic diisocyanate, such as 2, 4- triylene diisocyanate, 2, 6- triylene diisocyanate, 4, 4'- diphenylmethane diisocyanate, and / or isophorone diisocyanate, Polyurethane resin obtained by reacting alicyclic diisocyanate, such as hydrogenated diphenylmethane diisocyanate and hydrogenated xylene diisocyanate, with carboxyl group-containing polylactone polyol using a low molecular polyol having a carboxyl group having a number average molecular weight of 300 or less as an initiator Since the balance of adhesive strength and adhesiveness tends to be favorable, it is suitable as an adhesive for lamination.

As the low molecular polyol having a carboxyl group having a number average molecular weight of 300 or less in (B), specifically, 2,2-dimethylolpropionic acid (hereinafter weakly referred to as DMPA), 2,2-dimethylolbutanoic acid (hereinafter weakly referred to as DMBA), 2, And carboxyl group-containing polyols such as 2-hydroxyethyl propionic acid and 2,2-hydroxyethyl butanoic acid. These can be used individually or in mixture. The low molecular polyol containing a carboxyl group having a number average molecular weight of 300 or less becomes a polyurethane-based resin in which the carboxyl group is present in a pendant form in the molecular chain instead of at the molecular end when it is reacted with an isocyanate group. In the present invention, the particularly preferred low molecular polyol having a carboxyl group having a number average molecular weight of 300 or less is DMPA and / or DMBA. In addition, in this invention, "low molecular weight" means that the number average molecular weight measured value by gel permeation chromatography is 300 or less. In addition, the method of measuring the number average molecular weight of polyurethane-based resin is the same method as this.

(C) Preferred initiators used when obtaining a carboxyl group-containing polylactone polyol using a low molecular polyol having a carboxyl group having a number average molecular weight of 300 or less as an initiator are DMPA and / or DMBA. When such a low molecular weight polyol and an organic polyisocyanate react, the carboxyl groups present in the obtained polyurethane-based resin are present in pendant form in the molecular chain, not in the molecular terminal. In addition, the number average molecular weight of such carboxyl group-containing polylactone polyol is preferably 300 to 10,000, particularly 500 to 5,000.

As another initiator which can be used together with the low molecular weight polyol which has a number average molecular weight of 300 or less carboxyl group, ethylene glycol, 1, 2- propanediol, 1, 3- propanediol, 1, 2- butanediol, 1, 3- Butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentylglycol, 1,8-octanediol, 1,9-nonanediol , Alkylene oxide adducts such as diethylene glycol, 1,4-cyclohexanedimethanol or ethylene oxide and propylene oxide of bisphenol A, low molecular polyols containing no carboxyl groups such as trimethylolpropane, glycerin, pentaerythritol, Low molecular polyamines, such as hexamethylenediamine, xylenediamine, and isophorone diamine, low molecular amino alcohols, such as monoethanolamine and diethanolamine, etc. are mentioned. Moreover, you may use the polyester polyol, polycarbonate polyol, polyether polyol, etc. which are mentioned later. These can be used individually or in mixture.

Components other than the initiator used in the production of the carboxyl group-containing polylactone polyol include cyclic esters such as ε-caprolactone, γ-valerolactone and the like.

Examples of the active hydrogen group-containing compound that can be used in combination with (B) or (C) include long chain polyols and chain extenders. Such long chain polyols and chain extenders do not contain carboxyl groups.

The long-chain polyols include polyester polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, animal-based polyols, copolymerized polyols thereof, and the like. These long-chain polyols may be used alone or in combination of two or more thereof. The number average molecular weight of these long chain polyols is preferably 300 to 10,000, particularly 500 to 5,000. When the number average molecular weight is less than 300, the adhesiveness on the film substrate tends to be insufficient. In addition, when the number average molecular weight exceeds 10,000, durability tends to be insufficient. In this invention, the polyurethane-type resin which used 30-90 weight% of long chain polyols is preferable.

Examples of the polyester polyol include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, trimellitic acid, and the like. In at least one of known polycarboxylic acids, polycarboxylic acid esters or polycarboxylic acid anhydrides, and low molecular polyols, low molecular polyamines and low molecular amino alcohols, which do not contain a carboxyl group as an initiator used in the production of the polylactone polyols described above. Polyesters or polyesteramides obtained in one or more condensation reactions. Moreover, the active hydrogen obtained by ring-opening polymerization of cyclic ester (lactone) monomers, such as (epsilon) -caprolactone and (gamma) -valerolactone, using the low molecular polyol, low molecular polyamine, or low molecular amino alcohol which does not contain a carboxyl group as an initiator. Lactone-based polyesters at the end of the group.

Examples of the polycarbonate polyols include low molecular polyols and dealcoholization reactions such as diethylene carbonate, dimethyl carbonate, diethyl carbonate and diphenyl carbonate. As such low molecular weight polyols, there are those used in the production of the aforementioned polyester polyols.

As the polyether polyol, polyethylene glycol, poly, which is ring-opened-polymerized with ethylene oxide, propylene oxide, tetrahydrofuran and the like by using a low molecular polyol, a low molecular polyamine, or a low molecular amino alcohol used in the preparation of the polyester polyol described above as an initiator. Propylene glycol, polytetramethylene ether glycol, and the like, and a polyether polyol copolymerized therewith, and a polyester ether polyol using the above-described polyester polyol and polycarbonate polyol as an initiator.

Examples of the polyolefin polyols include hydroxyl group-containing polybutadiene, hydrogenated hydroxyl group-containing polybutadiene, hydroxyl-containing polyisoprene, hydrogenated hydroxyl-containing polyisoprene, hydroxyl-containing chlorinated polypropylene, hydroxyl-containing chlorinated polyethylene and the like.

Animal and plant polyols include castor oil-based polyols and silk fibroin.

If the number average molecular weight is 300 to 10,000 and has an active hydrogen group, epoxy resin, polyamide resin, polyester resin, acrylic resin, rosin resin, urea resin, melamine resin, phenol resin, coumarone resin, polyvinyl alcohol Resin, such as these, can also be used preferably.

Chain extenders are generally compounds having a number average molecular weight of less than 500 containing two or more active hydrogen groups in a molecule, and specifically, the above-described low molecular polyols, low molecular polyamines, low molecular amino alcohols and the like.

When obtaining a carboxyl group-containing polyurethane-based resin, the final equivalent ratio of isocyanate group and active hydrogen group is a factor such as the target number average molecular weight, the average number of functional groups of the organic polyisocyanate and the average number of functional groups of the active hydrogen group-containing compound. It is a ratio which calculates the conditions which do not gelatinize at the time of reaction, and satisfy | fills these conditions. This compounding ratio is based on the gelation theory calculated theoretically by J. P. Flory, Khun, etc., but can be prepared without gelation by actually reacting at a compounding ratio in consideration of the reactive ratio of the reactor included in the component.

A urethanation catalyst can be used for reaction of an active hydrogen group and an isocyanate group as needed. Specific examples thereof include organic metal compounds such as dibutyltin dilaurate (hereinafter abbreviated as DBTDL) and dioctyltin dilaurate, organic amines such as triethylenediamine and triethylamine, and salts thereof. Moreover, reaction temperature of an active hydrogen group and an isocyanate group is 30-120 degreeC, Especially 50-100 degreeC is preferable.

In addition, the one-shot method of reacting the active hydrogen group-containing compound and the organic polyisocyanate at once, or the prepolymer method of extending the reaction with the active hydrogen group-containing compound or organic polyisocyanate once the isocyanate group or the active hydrogen group terminal prepolymer is obtained. Can be synthesized. In addition, if necessary, aromatic solvents such as toluene and xylene, ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, ester solvents such as ethyl acetate and butyl acetate, dimethyl ether, diethyl ether, 1, Ether solvents such as 4-dioxane and tetrahydrofuran, alcohol solvents such as methanol, ethanol and isopropanol, single solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and pyridine and two or more kinds of mixtures You may use organic solvents, such as a solvent. Of course, it is also possible to react as it is without a solvent.

The number average molecular weight of the carboxyl group-containing polyurethane resin thus obtained is preferably 600 to 100,000, particularly 800 to 50,000.

The carboxyl group-containing polyurethane resin used in the present invention may be neutralized with neutralizing agents such as basic substances such as amines and alkalis, specifically triethylamine and sodium hydroxide, in order to improve adhesion to the film substrate.

In the adhesive for laminates of the present invention, a polyisocyanate curing agent may be used in combination to improve adhesive strength and durability. Examples of the polyisocyanate curing agent include organic polyisocyanates used in the production of the carboxyl group-containing polyurethane-based resins, and specific products include coronate L, coronate HL, coronate HX, and coronate 2030, which are manufactured by the Japanese Polyurethane Industry. have.

Among the polyisocyanate curing agents described above, a hydrophilic polar group-containing polyisocyanate curing agent obtained by reacting an organic polyisocyanate with a hydrophilic polar group-containing compound having one or more active hydrogen groups is preferable because of good adhesiveness. Such a hydrophilic polar group-containing polyisocyanate curing agent is more preferable because polyisocyanate having a hydrophilic polar group introduced into an aliphatic or alicyclic diisocyanate modified product having at least an isocyanurate group is excellent in heat resistance and the like. As such aliphatic or alicyclic diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, or hydrogenated xylene diisocyanate is preferable.

In the hydrophilic polar group-containing compound having an active hydrogen group, the hydrophilic polar group includes a nonionic polar group, an anionic polar group or a cationic polar group. These hydrophilic polar groups may be two or more hydrophilic polar groups of the same kind or different kinds. In consideration of the stability of the polyisocyanate curing agent obtained, it is preferable to introduce a nonionic polar group into a hydrophilic polar group.

As the nonionic polar group-containing compound having an active hydrogen group, poly (oxyalkylene) ethermonol, poly (oxyalkyl) having a repeating number of 3 to 90, more preferably 5 to 50, in an ethylene oxide unit of 50 mol% or more. Ethylene) ether polyol, poly (oxyalkylene) fatty acid ester monool, and the like. Preferred in the present invention are poly (oxyalkylene) ethermonols or poly (oxyalkylene) etherpolyols, more preferably poly (oxyalkylene) ethermonols.

In the preparation of the poly (oxyalkylene) ethermonol, initiators include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, cyclohexanol, phenol and the like. . In the production of poly (oxyalkylene) ether polyols, initiators include ethylene glycol, propylene glycol, aniline, trimethylolpropane, glycerin and the like. Among these, compounds having 5 or less carbon atoms, such as methanol, ethanol, ethylene glycol, and propylene glycol, are preferred because they have good adhesion in the metal-based film substrate, and more preferably, monools having 5 or less carbon atoms such as methanol and ethanol.

In the case of introducing a nonionic polar group, the content of ethylene oxide units in the polyisocyanate curing agent is preferably 0.1 to 40% by weight, particularly 0.5 to 30% by weight in terms of solid content.

In addition, hydrophobic groups may be introduced into the hydrophilic polar group-containing polyisocyanate curing agent in order to improve compatibility and the like. The hardener which introduce | transduced a hydrophobic group into a hydrophilic polar group containing polyisocyanate can be easily manufactured, for example by making the said hydrophilic polar group containing polyisocyanate react with a hydrophobic group and an active hydrogen group containing compound. Such hydrophobic and active hydrogen group-containing compounds include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, pentanol, hexanol, heptanol, octanol, 2-ethylhexane Low molecular weight monools such as ol, benzyl alcohol, cyclohexanol, alkylene glycol monoalkyl ether, low molecular weight primary monoamines such as ethylamine, butylamine and aniline, low molecular weights such as diethylamine, dibutylamine and methylaniline Higher monoamines, polyesters containing an active hydrogen group, polyethers containing less than 50 mol% of ethylene oxide units, polycarbonates containing an active hydrogen group, polyolefins containing an active hydrogen group, hydroxy higher fatty acids having 6 or more carbon atoms, and Esters and the like.

In the present invention, the average number of functional groups of the polyisocyanate curing agent is preferably 2.0 to 5.0, particularly 2.0 to 4.0. If the average functional group number is less than the lower limit, the crosslinking density of the cured product becomes small, so that the adhesive strength tends to be insufficient. In addition, when exceeding an upper limit, since the crosslinking density of hardened | cured material becomes large unnecessarily, the softness | flexibility of an adhesive bond layer will become inadequate easily.

In the present invention, the isocyanate group content of the polyisocyanate curing agent is preferably 10 to 50% by weight, particularly 15 to 45% by weight. When content of an isocyanate group is less than a lower limit, since the crosslinking density of hardened | cured material becomes small, adhesive strength tends to become inadequate. In addition, when exceeding an upper limit, since the crosslinking density of hardened | cured material becomes large unnecessarily, the softness | flexibility of an adhesive bond layer will become inadequate easily.

The blending ratio of the polyisocyanate curing agent to the resin (topic) having a dynamic wettability of 0.20 mN or more is preferably 0.5 to 30 parts by weight, in particular 1 to 20 parts by weight, based on 100 parts by weight of the main ingredient in terms of solid content. When the amount of the curing agent blended is less than the lower limit, the blending effect of the curing agent is hardly obtained. In addition, when the compounding quantity of a hardening | curing agent exceeds an upper limit, since excessive isocyanate groups react with water and a carboxyl group, and generate | occur | produce carbonic acid gas, delamination etc. tend to occur.

To the adhesive of the present invention, additives such as catalysts, coupling agents, antioxidants, ultraviolet absorbers, pigments, dyes, flame retardants, hydrolysis inhibitors, lubricants, plasticizers, fillers, storage stabilizers and the like can be suitably blended. In particular, the addition of a coupling agent is preferred because of the improvement of workability and adhesive strength.

Coupling agents include silane coupling agents, titanium coupling agents, aluminum coupling agents and the like, but silane coupling agents are particularly suitable. The amount of the coupling agent added to 100 parts by weight of the polyurethane resin solids is preferably 0.05 to 10.00 parts by weight, particularly 0.1 to 5.00 parts by weight. Such addition amount is calculated in consideration of the base film coating area, coating efficiency and adhesive performance of the coupling agent.

Examples of the silane coupling agent include vinylsilane compounds such as γ-methacryloxypropyltrimethoxysilane and vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxypropyl. Epoxysilane compounds such as trimethoxysilane, aminosilane compounds such as γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, and γ-mercaptopropyltrime Mercaptosilane compounds, such as oxysilane, are suitable. In particular, an epoxysilane compound is preferable at the point of improving adhesiveness.

Next, the manufacturing method of the laminate film using the adhesive agent for laminates of this invention is explained in full detail.

Although the adhesive agent for laminates of this invention is an adhesive most suitable for obtaining the laminated film using the metallic film base material represented by one or more metal foils, such as aluminum foil and copper foil, and metal vapor deposition films, such as an aluminum vapor deposition film, It can also be suitably used to obtain a laminate film of.

Film base materials used in the laminate include low density polyethylene film, high density polyethylene film, unstretched PP film, stretched PP film, polyolefin film such as polybutylene film, polystyrene film, polyvinylidene chloride film, PET film, polybutylene Polyester films such as terephthalate film, polyethylene naphthalate film, polybutylene naphthalate film, nylon film, polyvinyl chloride film, ethylene vinyl acetate copolymer film, ethylene vinyl alcohol copolymer film, polyvinyl alcohol film, cellophane film, In addition to an ethylene acrylate copolymer film, an ionic polymer resin film, a polycarbonate film, an aluminum foil, a copper foil, an aluminum vapor deposition film in which aluminum is deposited on these films, and a copper vapor deposition film in which copper is deposited on each of the above films , Paper and polymer coated films thereof.

In the film, the plastic film is preferable in that the surface treatment such as corona discharge treatment improves the adhesive strength. In addition, the polymer coating film needs to consider the kind, amount, surface characteristics, etc. of the polymer to be coated.

Next, with regard to the lamination method, a method such as wet lamination, dry lamination, hot melt lamination, nonsolvent lamination, extrusion lamination, or the like may be applied.

The application amount of the adhesive is from 0.5 to 10g / m ^2, especially 1 to 5g / m ² in terms of solid mass is preferred. If the coating amount is outside this range, the adhesive strength tends to be insufficient.

It adds together, applying an adhesive agent to a film base material. Thereafter, if necessary, by pressing or heating to accelerate the curing reaction.

In this way, not only two film base materials are laminated | stacked, but also three or more film base materials are laminated | stacked, and manufacture becomes possible.

Example

The present invention will be described by the following examples, but the present invention is not limited to these examples. Incidentally, in the examples, "parts" denotes parts by weight and "%" denotes weight percent, respectively.

Synthesis of Polyurethane Resin

Synthesis Example 1

389 parts of polyol A, 51 parts of polyol B, and 215 parts of ethyl acetate were put into the reactor equipped with the stirrer, the thermometer, the nitrogen sealing tube, and the cooler, and it melt | dissolved at 50 degreeC. Subsequently, 60 parts of IPDI and 0.1 part of DBTDL were placed and reacted at 70 ° C for 5 hours. When the isocyanate group absorption peak of infrared absorption analysis disappeared, 285 parts of ethyl acetate was added and diluted, and the polyurethane-based resin PU-A of 50% of solid content was obtained.

Synthesis Examples 2 to 10

 Using the components shown in Tables 1 and 2 in the same manner as in Synthesis example 1, polyurethane-based resins PU-B to J having a solid content of 50% were obtained.

Synthesis Example 11

864 parts of polyol C and 51 parts of polyol B were put into the same reactor as the synthesis example 1, and it stirred and mixed at 50 degreeC for 1 hour. Subsequently, 85 parts of MDI was added and reacted at 75 ° C for 3 hours. It was confirmed that the isocyanate group absorption peak of infrared absorption analysis disappeared, and polyurethane-based resin PU-K having a solid content of 100% was obtained.

Synthesis Examples 12-14

Polyurethane-based resins PU-L to N having a solid content of 100% were obtained using the components shown in Table 2 in the same manner as in Synthesis example 11.

Tables 1 and 2 show each synthetic raw material, solid content, carboxyl group content, number average molecular weight measurement result and dynamic wettability measurement result of PU-A to N.

How to measure dynamic wettability

For Synthesis Examples 1 to 14 and Tables 1 and 2

Polyol A: Polyester diol obtained from 1/1 ethylene glycol / neopentyl glycol and 1/1 (each molar ratio) sebacic acid / isophthalic acid (number average molecular weight = 2,000)

Polyol B: A carboxyl group-containing polylactone polyol obtained by reacting ε-caprolactone with DMBA (initiator) (number average molecular weight = 500)

Polyol C: Poly obtained from ethylene glycol / neopentyl glycol / 3-methyl-1,5-pentane glycol at 2/2/1 and sebacic acid / isophthalic acid / adipic acid at 2/2/1 (each molar ratio) Ester diol (number average molecular weight = 700)

DMBA: 2,2-dimethylolbutanoic acid

DMPA: 2,2-dimethylolpropionic acid

IPDI: isophorone diisocyanate

H ₆ XDI: hydrogenated xylene diisocyanate

HDI: hexamethylene diisocyanate

MDI: 4,4'-diphenylmethane diisocyanate

DBTDL: Dibutyltin Dilaurate

PP (Film): RXC-11 (70μ thick, manufactured by Tosero)

PET (Film): E-5100 (12μ thick, Dongbangbang)

Aluminum foil: Alumi Haku C (thickness 15μ, Dongyang Aluminum)

Relationship between carboxyl group content and dynamic wettability

Table 3 shows the relationship between the carboxyl group concentration and the dynamic wettability of PU-E, F, G, and J for which the raw material composition is the same and the carboxyl group concentration in the molecular chain is different.

As shown in Table 3, by introducing the carboxyl group into the molecular chain of the polyurethane-based resin, the dynamic wettability to the PP film, the PET film and the aluminum foil was remarkably improved.

Synthesis of Polyisocyanate Curing Agent

Synthesis Example 15

86 parts of C-HX, an isocyanurate-modified type of hexamethylene diisocyanate, and 14 parts of monool (1) were added to the same reactor as in Synthesis Example 1, and reacted at 70 ° C for 3 hours to obtain a polyisocyanate curing agent A. It was. Isocyanate group content of the hardening | curing agent A was 16.8%.

Deposition Test

Formulation of Adhesive

Laminate adhesives AD-A to N were blended in the proportions shown in Tables 4 and 5.

About synthesis example 15 and Tables 4 and 5

C-L: Adduct modification type of triylene diisocyanate (trade name; Coronate L, Japanese Polyurethane Industry, Solids = 75%)

Monool (1): methoxy poly (oxyethylene) monool (ethylene oxide unit = 100 mol%, number average molecular weight = 400)

C-HL: Adduct modification type of hexamethylene diisocyanate (brand name: Coronate HL, Japan Polyurethane Industry, solid content = 75%)

C-HX: Type of isocyanurate modification of hexamethylene diisocyanate (trade name: Coronate HX, Japanese Polyurethane Industry, Solids = 100%)

A-186: β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (manufactured by Japan Unika)

A-187: gamma-glycidoxypropyltrimethoxysilane (manufactured by UNIKA Japan)

Measurement of Adhesion Strength-1

Example 1

AD-A, PP film, PET film, and aluminum foil were set to the dry laminate. AD-A was applied to the corona treated surface of the PET film with gravure roll so as to dry to 3.5 g / m ² . After apply | coating an adhesive agent, after passing through the drying furnace of 80 degreeC, it combined with the aluminum foil by the roll which adds and combines under 0.3 MPa at 100 degreeC. Subsequently, AD-A was applied to aluminum foil so that the coating amount might dry to 3.5 g / m <^2> . After apply | coating an adhesive agent, it passed through the drying furnace of 80 degreeC, and combined with the corona treatment surface of a PP film by the roll which adds under 0.3 MPa at 100 degreeC, and combined. In addition, the film speed is 50 m / min. After lamination, curing was performed at 40 ° C. for 3 days to obtain laminate film A.

The laminate film A was cut to a width of 15 mm to carry out a T-type peeling test at a tensile rate of 300 mm / min and a measurement atmosphere of 25 ° C. × 50% RH.

Further, laminate film A was heat sealed to three sides under conditions of 1 second under 180 MPa at 0.3 ° C with the PP side inward, and then ketchup / salad oil / vinegar = 1/1/1 (weight ratio). A mixed solution of was added thereto and sealed by heat sealing under the above conditions. After a retort treatment at 120 ° C. for 30 minutes, a T-type peeling test (sample width: 15 mm, tensile rate: 300 mm / min, measurement atmosphere: 25 ° C. × 50% RH) was performed.

Examples 2 to 8, Comparative Examples 1 and 2

Using AD-B to J, using the same procedure as in Example 1, laminate films B to J were prepared and tested.

Table 6 shows the test results of Examples 1 to 8 and Comparative Examples 1 and 2.

For Examples 1-8, Comparative Examples 1-2 and Table 6

PP (Film): RXC-11 (Tosei Corporation)

PET (Film): E-5100 (Oriental)

Aluminum foil: Alumin Haku C (made by Dongyang Aluminum)

PETf: PET Material Destruction

Alf: aluminum foil destruction

As a result of examining Tables 1 to 3 and 6, it was found that the adhesive for lamination using a polyurethane-based resin having a dynamic wettability of 0.2 mN or more showed good results in both the adhesive strength and the adhesive strength after the retort treatment. In addition, in comparison with AD-E, F, G, and J, in particular, it was found that an adhesive having improved dynamic wettability by introducing a carboxyl group into the molecular chain of a polyurethane-based resin also improved adhesive performance.

Measurement of Adhesion Strength-2

Example 9

AD-K was heated at 60 degreeC, and the adhesive agent was apply | coated so that the application amount might be 2.5 g / m <^2> on the corona treated surface of PET film with a roll coater. The adhesive coated surface and the aluminum deposited surface of the aluminum vapor-deposited unstretched straight chain low density polyethylene film (film film: 60 micrometers) were added together by the roll which adds under 0.3 MPa at 100 degreeC. In addition, the film speed is 50 m / min. After lamination, curing was carried out at 40 ° C. for 3 days to obtain laminate film K.

The laminated film K was cut into a 15 mm width as it was, and a T-type peeling test was performed at a tensile rate of 300 mm / min and a measuring atmosphere of 25 ° C. × 50% RH.

Example 10, Comparative Examples 3 and 4

The test was carried out by preparing laminate films L to N in the same manner as in Example 9 using AD-L to N.

The test results of Examples 9 and 10 and Comparative Examples 3 and 4 are shown in Table 7.

About Examples 9 and 10, Comparative Examples 3 and 4 and Table 7

PET (Film): E-5100

VM-LLDPE: Aluminum Evaporated Unstretched Straight Chain Low Density Polyethylene Film (Thickness: 60μ)

PETf: PET Material Destruction

As described above, according to the present invention, by using a resin having a dynamic wettability of 0.2 mN or more, it is possible to provide a laminate adhesive having good adhesion to various films and metal foils.

Claims (5)

An adhesive for laminates comprising a polyurethane-based resin having a dynamic wettability of 0.20 mN or more and a carboxyl group content of 0.01 to 10.0 mmol / g for a film substrate. The method of claim 1, The adhesive for laminates whose film base material is one or more types of film base materials chosen from the group which consists of a polypropylene film, a polyethylene terephthalate film, and aluminum foil. 0.5-30 weight of the said polyisocyanate hardening | curing agent with respect to 100 weight part of said polyurethane-type resins in terms of solid content of the polyurethane-type resin and polyisocyanate hardening | curing agent whose dynamic wettability with respect to a film base material is 0.20 mN or more and a carboxyl group content is 0.01-10.0 mmol / g. Adhesive for laminates, which is contained at negative compounding ratio. The method of claim 3, wherein The adhesive for laminates whose film base material is one or more types of film base materials chosen from the group which consists of a polypropylene film, a polyethylene terephthalate film, and aluminum foil. The method according to claim 3 or 4, Adhesive for laminates whose polyisocyanate hardener is a polar group containing polyisocyanate hardener.

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