TW202330839A - Composition for adhesive, and laminate - Google Patents

Abstract

Provided is a composition for adhesives which gives an adhesive with which a metal foil and a resinous film can be tenaciously bonded to each other even at high temperatures. The composition for adhesives comprises: an acid-modified polyolefin (component 1); a polyisocyanate compound (component 2) which is a compound comprising a framework and p (p is an integer of 2 or lager) isocyanato groups bonded thereto; a modified isocyanate compound (component 3) which is a compound comprising a framework having the same structure as that of the polyisocyanate compound of component 2 and, bonded thereto, q (q is an integer of 1 or lager) isocyanato group(s) and r (r is an integer of 1 or larger and satisfies q+r=p) modifying group(s); a reaction catalyst (component 4); and a solvent (component 5). When the total number of moles of the isocyanato groups contained in component 2, the total number of moles of the isocyanato groups contained in component 3, and the total number of moles of the modifying groups contained in component 3 are respectively expressed by Ia, Ib, and H, then the ratio of H to the sum of Ia, Ib, and H, H/(Ia+Ib+H), is larger than 0 but not larger than 0.5.

Description

Adhesive composition and laminate

The present invention relates to an adhesive composition and a laminate obtained by using the adhesive composition.

A laminate having a laminated structure in which metal foil and a resin film are bonded and laminated with an adhesive can be used as a packaging material for water, oil, food, pharmaceuticals, chemicals, etc. Since these packaging materials are exposed to high temperature, the adhesive is required to have excellent adhesiveness at high temperature. [Prior Art Literature] [Patent Document]

[Patent Document 1] International Publication No. 2018/116555

[Problem to be solved by the invention]

For example, Patent Document 1 discloses an adhesive for lamination of a metal foil and a resin film, and describes that it exhibits good adhesiveness even at high temperatures, but further improvement in adhesiveness at high temperatures is required for the adhesive. The object of the present invention is to provide an adhesive composition that can obtain an adhesive that can firmly bond a metal foil and a resin film even at high temperatures, and that is difficult to peel off the metal foil and the resin film even at high temperatures. laminated body. [Means to solve the problem]

In order to solve the above-mentioned problems, one aspect of the present invention is as follows [1]-[9]. [1] An adhesive composition for obtaining an adhesive for bonding a metal foil and a resin film, comprising: (Component 1) Acid-modified polyolefin having carboxyl groups, (Component 2) A polyisocyanate compound having p (p is an integer greater than 2) isocyanate groups bonded to the core, (Component 3) On the mother core having the same structure as the polyisocyanate compound of the aforementioned component 2, there are q (q is an integer of 1 or more) isocyanate groups and r (r is an integer of 1 or more) bonded to the core of the polyisocyanate compound, and q+r is satisfied =p) Modified isocyanate compounds of compounds with modifying groups, (Component 4) a reaction catalyst that promotes the reaction of the carboxyl group possessed by the aforementioned component 1 and the isocyanate group possessed by the aforementioned component 2 and the aforementioned component 3, and (ingredient 5) solvent, The aforementioned modifying group possessed by the modified isocyanate compound of the aforementioned component 3 is obtained by reacting the aforementioned functional group having active hydrogen of the isocyanate group bonded to the aforementioned mother core and the active hydrogen compound having a functional group having active hydrogen the foundation of which was born, Let the total number of moles of the isocyanate groups of the polyisocyanate compound of the aforementioned component 2 be Ia, the total molar number of the isocyanate groups of the modified isocyanate compound of the aforementioned component 3 be set as Ib, and the aforementioned component 3 When the total number of moles of the aforementioned modifying groups possessed by the modified isocyanate compound is H, the ratio H/(Ia+Ib+H) of H to the total number of moles of Ia, Ib, and H exceeds 0 and 0.5 the following.

[2] The adhesive composition according to [1], wherein the functional group having an active hydrogen is at least any one of a hydroxyl group and a carboxyl group. [3] The adhesive composition according to [1], wherein the active hydrogen compound is at least one compound selected from monovalent alcohols and monovalent carboxylic acids. [4] The adhesive composition according to any one of [1] to [3], wherein the polyisocyanate compound is a saturated aliphatic polyisocyanate.

[5] The adhesive composition according to any one of [1] to [3], wherein the polyisocyanate compound is an isocyanurate body of a saturated aliphatic polyisocyanate and a urea of a saturated aliphatic polyisocyanate At least one compound in the carbamate body. [6] The adhesive composition according to any one of [1] to [5], wherein the acid-modified polyolefin is a polyolefin containing one or more of propylene, ethylene, and butene as a monomer acid modifier.

[7] The adhesive composition according to any one of [1] to [6], wherein the acid-modified polyolefin contains polyolefin modified with at least one kind selected from ethylenically unsaturated carboxylic acids and their anhydrides. Acid modifier of quality.

[8] A laminate comprising a metal foil, a resin film, and an adhesive layer for bonding the metal foil and the resin film between the metal foil and the resin film, wherein the adhesive layer is Formed from an adhesive containing a reaction product of the adhesive composition according to any one of [1] to [7]. [9] The laminate according to [8], wherein the metal foil is an aluminum foil, and the resin film is a heat-fusible resin film. [Invention effect]

According to the present invention, it is possible to provide a laminate in which the metal foil and the resin film can be firmly bonded even at high temperatures, and the metal foil and the resin film are difficult to peel off even at high temperatures.

One embodiment of the present invention will be described below. Moreover, this embodiment shows an example of this invention, and this invention is not limited to this embodiment. Furthermore, various changes or improvements can be made to this embodiment, and the form which added these changes or improvements can also be included in this invention.

A laminate 1 of this embodiment will be described with reference to FIG. 1 . A laminate 1 shown in FIG. 1 includes a metal foil 2 , a resin film 3 , and an adhesive layer 4 interposed between the metal foil 2 and the resin film 3 to bond the metal foil 2 and the resin film 3 . This adhesive agent layer 4 is formed with the adhesive agent containing the reaction product of the adhesive agent composition of this embodiment mentioned later in detail.

This laminated body 1 can be used as a packaging material for storing various articles, but since the metal foil 2 and the resin film 3 are strongly bonded by the adhesive layer 4 and are not easily peeled even at high temperatures, it can be preferably used as a packaging material exposed to Packaging materials for high temperature (for example, a temperature of 80°C or higher or a temperature of 100°C or higher). For example, it can be used as a packaging material for water, oil, food, medicine, chemicals, etc. Examples of foods include edible vinegar and highly acidic foods with a high content of free fatty acids. Examples of chemicals include acids, alkalis, and organic solvents.

[metal foil] The type of metal forming the metal foil 2 is not particularly limited, but examples thereof include aluminum, aluminum alloy, stainless steel, and aluminum-iron alloy. When the laminate is used as a packaging material for storing food, pharmaceuticals, chemicals, etc., the metal foil 2 can impart gas barrier properties to the inside of the packaging material to suppress the intrusion of oxygen and moisture. The thickness of the metal foil 2 is not particularly limited, but may be not less than 5 μm and not more than 50 μm.

[resin film] The type of resin forming the resin film 3 is not particularly limited, but examples thereof include polyolefin, polyester, polyvinyl chloride, and polyamide. Specific examples of polyolefins include polyethylene, polypropylene, and their copolymers, and their acid-modified products and ionomers. Specific examples of polyester include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). Specific examples of polyvinyl chloride include rigid polyvinyl chloride and soft polyvinyl chloride that do not contain a plasticizer. Specific examples of polyamide include polyhexamethylene adipamide (66 nylon) and polycaprolactamide (6 nylon). When the laminate is used as a packaging material for storing food, pharmaceuticals, chemicals, etc., excellent acid resistance and chemical resistance can be imparted by the resin film 3 .

Moreover, if the resin film 3 is a heat-fusible resin film, heat sealability can be imparted to the laminate 1 . The type of the heat-fusible resin forming the heat-fusible resin film is not particularly limited as long as it is a heat-fusible and thermoplastic resin, and examples thereof include polypropylene and polypropylene copolymers. The term "hot-melt" in the present invention means that when the hot-melt resin is heated above a certain temperature, it softens, and the resin that is in close contact with the hot-melt resin melts with a resin made of the same material or a different material.

The thickness of the resin film 3 is not particularly limited, but may be set to, for example, not less than 20 μm and not more than 150 μm, or may be set to be not less than 30 μm and not more than 100 μm. By making it 20 micrometers or more, pinhole generation|occurrence|production can be fully prevented. In addition, by setting the thickness to 150 μm or less, the amount of resin used can be reduced and cost reduction can be achieved.

[adhesive layer] The adhesive agent layer 4 which adheres the metal foil 2 and the resin film 3 is formed with the adhesive agent containing the reaction product of the composition for adhesive agents of this embodiment. Hereinafter, the composition for adhesive agents of this embodiment used in order to obtain the adhesive agent which forms the adhesive agent layer 4 is demonstrated.

The adhesive composition of this embodiment contains the following (component 1), (component 2), (component 3), (component 4) and (component 5). (Component 1) Acid-modified polyolefin having carboxyl groups, (Component 2) A polyisocyanate compound having p (p is an integer greater than 2) isocyanate groups bonded to the core, (Ingredient 3) On the mother core with the same structure as the polyisocyanate compound of Ingredient 2, there are q (q is an integer of 1 or more) isocyanate groups and r (r is an integer of 1 or more) bonded to the core of the polyisocyanate compound of ingredient 2, and q+r= p) Modified isocyanate compounds of compounds with modifying groups, (Component 4) a reaction catalyst that promotes the reaction of the carboxyl group contained in component 1 with the isocyanate group contained in component 2 and component 3, and (Component 5) Solvent.

Hereinafter, each component of the adhesive composition of this embodiment is demonstrated. (1) Acid-modified polyolefin (ingredient 1) Acid-modified polyolefins are polyolefins acid-modified and carboxyl groups introduced. As the acid-modified polyolefin, for example, a modified polyolefin resin grafted with at least one selected from ethylenically unsaturated carboxylic acids and their anhydrides, and monomers such as ethylene, propylene, butene, etc. A copolymer resin obtained by copolymerizing at least one kind of ethylenically unsaturated carboxylic acid and its anhydride.

Examples of the polyolefin component of the acid-modified polyolefin include homopolymers of monomers such as ethylene, propylene, and butene, and copolymers obtained by copolymerizing one or more of these monomers. As the acid component of acid-modified polyolefin (acid for modifying polyolefin), for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, fumaric anhydride, itaconic acid can be used , itaconic anhydride, etc. These ethylenically unsaturated carboxylic acids may be used alone or in combination of two or more.

Among the above-mentioned polyolefin components, a copolymer of propylene and an olefin other than propylene is preferable, and a copolymer of propylene and an olefin including butene is more preferable. For the copolymer of propylene and butene, the copolymerization ratio is preferably 90:10~70:30 (molar ratio) of propylene:butene, more preferably 87:13~72:28, and more preferably For 82:18~75:25.

And as the acid-modified polyolefin, it is preferable to use at least one modified polyolefin resin selected from ethylenically unsaturated carboxylic acids and their anhydrides grafted on polyolefin, more preferably to use the modified polyolefin resin selected from maleic anhydride and its anhydrides. Modified polyolefin resin in which at least one acid anhydride is grafted to polyolefin.

When the acid-modified polyolefin is used as a modified polyolefin resin (maleic anhydride-modified polyolefin resin) grafted with maleic anhydride on the polyolefin, the ratio of maleic anhydride to the total amount of the acid-modified polyolefin It is preferably in the range of 0.6 mass % to 3.0 mass %, more preferably in the range of 0.7 mass % to 2.5 mass %, still more preferably in the range of 0.8 mass % to 2.0 mass %.

The acid value of the acid-modified polyolefin is preferably not less than 1 mgKOH/g and not more than 40 mgKOH/g, more preferably not less than 3 mgKOH/g and not more than 30 mgKOH/g, and more preferably not less than 5 mgKOH/g and not more than 20 mgKOH/g. In addition, the mass of potassium hydroxide (KOH) required to neutralize 1 g of polyolefin resin in the acid value system in the present invention can be obtained by the method described in JIS K0070.

In addition, the melting point of the acid-modified polyolefin is preferably 70°C to 110°C, more preferably 70°C to 100°C, more preferably 75°C to 95°C, particularly preferably 75°C to 90°C. The melting point here is measured at a heating rate of 10° C./min in differential scanning calorimetry under the conditions described in the Examples.

The heat of fusion of the acid-modified polyolefin is preferably in the range of 5 J/g to 60 J/g, more preferably in the range of 10 J/g to 50 J/g, and more preferably in the range of 15 J/g to 40 J/g . If the heat of fusion of the acid-modified polyolefin is in the range of 5 J/g to 60 J/g, the cohesive force derived from crystallization can be maintained, so the adhesiveness and heat resistance can be maintained, and the acid-modified polyolefin can be maintained. Solvent stability and fluidity. As a result, the workability at the time of handling the composition for adhesive agents is favorable. The heat of fusion here is measured under the same conditions as the above-mentioned melting point measurement, and the heat of fusion is calculated from the area surrounded by the extended line of the reference line and the melting peak.

The weight average molecular weight (Mw) of the acid-modified polyolefin is preferably in the range of 60,000 to 150,000, more preferably in the range of 70,000 to 140,000, and more preferably in the range of 80,000 to 130,000. The number average molecular weight (Mn) of the acid-modified polyolefin is preferably in the range of 30,000 to 90,000, more preferably in the range of 35,000 to 80,000, and more preferably in the range of 40,000 to 70,000. Here, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are the weight average molecular weight and number average molecular weight in terms of polystyrene measured by the gel permeation chromatography.

The melt mass flow rate of the acid-modified polyolefin is preferably in the range of 2 g/10 minutes to 60 g/10 minutes, more preferably 10 g/10 minutes to 50 g/10 minutes, and more preferably 25 g/10 minutes Above 45g/10 minutes below the range. The melt mass flow rate here is measured in accordance with JIS K7210-1:2014 under the conditions of a temperature of 130° C. and a load of 2.16 kg.

The content of the acid-modified polyolefin in the adhesive composition of this embodiment is not particularly limited, but the non-volatile matter in the adhesive composition of this embodiment, that is, the total amount of the self-adhesive composition When the amount obtained by subtracting the amount of the solvent of component 5 is 100% by mass, the content of the acid-modified polyolefin is preferably from 55% by mass to 96% by mass, more preferably from 60% by mass to 90% by mass , and more preferably not less than 65% by mass and not more than 85% by mass.

(2) Polyisocyanate compound (component 2) The polyisocyanate compound of component 2 has a plurality of isocyanate groups (-NCO), and if described in detail, it is a compound in which p (p is an integer of 2 or more) isocyanate groups are bonded to the core. In the present invention, the term "core core" refers to the part obtained by removing the isocyanate group from the polyisocyanate compound of component 2. Examples of the chemical structure that constitutes the core, that is, the chemical structure before the isocyanate group is bonded, are aromatic compounds such as benzene, toluene, xylene, naphthalene, anthracene, or methane, butane, n-hexane, and cyclohexane Chain or cyclic saturated or unsaturated aliphatic compounds such as alkanes, or heterocyclic compounds, etc. Examples of the parent nucleus when p is 2 include phenylene, alkylene and cycloalkylene.

As the polyisocyanate compound of the component 2, a saturated aliphatic polyisocyanate can be used. And, as the polyisocyanate compound of the component 2, at least one compound selected from the isocyanurate body of saturated aliphatic polyisocyanate and the allophanate body of saturated aliphatic polyisocyanate can be used.

Specific examples of the polyisocyanate compound of component 2 include butylene diisocyanate, pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), Cyclopentyl diisocyanate, cyclohexylene diisocyanate, norbornene diisocyanate, hydrogenated xylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hydrogenated diphenylmethane diisocyanate, hydrogenated toluene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, etc.

Moreover, as a specific example of the polyisocyanate compound of component 2, the modified body of each said diisocyanate is mentioned. For example, the isocyanurate body of pentameric diisocyanate, and the urethane body of the adduct body of urethane group and diisocyanate formed by the reaction of diisocyanate and alcohol, and Carbodiimide modification of diisocyanate, and diol modification of diisocyanate.

The polyisocyanate compound of component 2 may be the above-mentioned diisocyanate having 2 isocyanate groups, may be a triisocyanate having 3 isocyanate groups, or may be an isocyanate compound having 4 or more isocyanate groups. The polyisocyanate compounds of these component 2 may be used individually by 1 type, and may use 2 or more types together.

(3) Modified isocyanate compound (component 3) The modified isocyanate compound of component 3 is an isocyanate compound having one or more isocyanate groups and one or more modifying groups. If described in detail, it is a compound in which q isocyanate groups and r modifying groups are bonded to the core. Both q and r are integers of 1 or more, and satisfy q+r=p. As mentioned above, p is the number of isocyanate groups bonded to the core of the polyisocyanate compound of component 2. Also, the core of the polyisocyanate compound of component 2 and the core of the modified isocyanate compound of component 3 have the same structure.

The modifying group of the modified isocyanate compound of component 3 is a group produced by the reaction of the isocyanate group bonded to the core and the active hydrogen compound having the functional group having active hydrogen. Examples of the functional group having active hydrogen include hydroxyl group, carboxyl group, mercapto group, and amino group, but preferably at least one of hydroxyl group and carboxyl group. When the functional group having active hydrogen is a hydroxyl group, the modifying group becomes a group having a urethane bond, and when the functional group having active hydrogen is a carboxyl group, the modifying group becomes a group having an amide bond.

The method for producing the modified isocyanate compound is not particularly limited, but can be produced by reacting an active hydrogen compound with a polyisocyanate compound having the same chemical structure as the polyisocyanate compound of component 2. For example, a modified isocyanate compound can be obtained by reacting an active hydrogen compound having one hydroxyl group with a diisocyanate and appropriately controlling the amount of the active hydrogen compound having one hydroxyl group used in the reaction. The modified isocyanate compound obtained in this example is a compound in which only one of the two isocyanate groups of the diisocyanate reacts with the hydroxyl group of the active hydrogen compound to form a urethane bond. It has one isocyanate group and one modified base compound.

Therefore, the polyisocyanate compound of component 2 and the modified isocyanate compound of component 3 are separately prepared and used as raw materials of the adhesive composition, but they may also be prepared as follows. That is, an active hydrogen compound is added to the polyisocyanate compound of component 2, a part of the polyisocyanate compound of component 2 is reacted with an active hydrogen compound to form a modified isocyanate compound of component 3, and the polyisocyanate compound of component 2 and the polyisocyanate compound of component 3 are produced. A mixture of modified isocyanate compounds that can be used as a raw material for adhesive compositions.

Examples of active hydrogen compounds include monohydric alcohols, monovalent carboxylic acids, monohydric mercaptans, and monovalent amines, and are preferably at least one compound selected from monohydric alcohols and monovalent carboxylic acids. Furthermore, the carbon number of the monovalent alcohol and the monovalent carboxylic acid is preferably from 1 to 20, more preferably from 2 to 15, and still more preferably from 3 to 12.

Specific examples of monohydric alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, tert-butanol, 2-ethylhexanol, n-decyl alcohol, and n-dodecane alcohol, n-octanol. Specific examples of the monovalent carboxylic acid include acetic acid, propionic acid, and butyric acid. The active hydrogen compound may be used alone or in combination of two or more.

Here, in the adhesive composition of the present embodiment, the total molar number of isocyanate groups possessed by the polyisocyanate compound of component 2 is defined as Ia, and the total molar number of isocyanate groups possessed by the modified isocyanate compound of component 3 is When the number of moles is Ib and the total number of moles of the aforementioned modifying groups contained in the modified isocyanate compound of component 3 is H, the ratio of H to the total number of moles of Ia, Ib, and H is H/( Ia+Ib+H) is more than 0 and 0.5 or less.

From the composition for an adhesive agent in which the ratio H/(Ia+Ib+H) is within the above range, an adhesive agent capable of firmly adhering metal foil and a resin film even at high temperature can be obtained. The ratio H/(Ia+Ib+H) is preferably more than 0 and not more than 0.5, more preferably not less than 0.01 and not more than 0.4, and still more preferably not less than 0.015 and not more than 0.34.

In addition, in the adhesive composition of the present embodiment, the total molar number of carboxyl groups possessed by the acid-modified polyolefin is represented as C, and the total molar number of isocyanate groups possessed by the polyisocyanate compound of component 2 is represented by C. When Ia is the total number of moles of isocyanate groups possessed by the modified isocyanate compound of component 3 as Ib, the ratio of the total number of moles of Ia and Ib to C (Ia+Ib)/C is preferably 0.3 Above 30 and below.

From the adhesive composition in which the ratio (Ia+Ib)/C is within the above range, an adhesive capable of firmly bonding metal foil and a resin film even at high temperature can be obtained. The ratio (Ia+Ib)/C is more preferably from 1.0 to 20, more preferably from 2.0 to 15, particularly preferably from 3.0 to 12. In the present invention, the carboxylic acid anhydride (-C(=O)-O-C(=O)-) of the dehydration condensation product of two carboxyl groups is defined as one having one carboxylic acid anhydride group and two carboxyl groups.

In addition, in the adhesive composition of the present embodiment, the total amount of the polyisocyanate compound of component 2 and the modified isocyanate compound of component 3 is preferably as follows. That is, when the amount obtained by subtracting the amount of component 5 from the total amount of the adhesive composition is 100% by mass, the total amount of component 2 and component 3 is preferably more than 0% by mass and less than 40% by mass, more preferably It is 2 mass % or more and 35 mass % or less.

(4) Reaction catalyst (ingredient 4) The reaction catalyst of component 4 is a catalyst that promotes the reaction between the carboxyl group of the acid-modified polyolefin of component 1 and the isocyanate group of the polyisocyanate compound of component 2 and the modified isocyanate compound of component 3. The type of reaction catalyst of component 4 is not particularly limited as long as it can accelerate the reaction between carboxyl group and isocyanate group, but for example, organotin compound, tertiary amine, etc. can be used.

Specific examples of the organotin compound include dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, and dioctyltin dimaleate. In addition, specific examples of tertiary amines include tetraalkylethylenediamine such as tetramethylethylenediamine, N,N'-dialkylbenzylamine such as dimethylbenzylamine, trialkylene Ethyldiamine, pentamethylenediethylenetriamine, N-ethylmorpholine, N-methylmorpholine, 1-methyl-4-dimethylaminoethylpiperidine and diazabicyclodeca One carbene etc. The reaction catalyst may be used alone or in combination of two or more.

When using this reaction catalyst, when the amount obtained by subtracting the amount of the solvent of component 5 and the amount of the reaction catalyst of component 4 from the total amount of the adhesive composition of this embodiment is 100 parts by mass, the reaction The ratio of the amount of the catalyst is preferably from 0.01 to 3 parts by mass, more preferably from 0.05 to 2.5 parts by mass, and still more preferably from 0.2 to 2 parts by mass. If the ratio of the amount of reaction catalyst is in this range, it is easy to obtain the usable time after mixing and the reaction product of the adhesive composition of this embodiment. The balance of power and time.

(5) Solvent (ingredient 5) The type of solvent used in the adhesive composition of this embodiment is not particularly limited as long as it can dissolve or disperse the acid-modified polyolefin, but is preferably an organic solvent that can dissolve the acid-modified polyolefin. And as an organic solvent, it is preferable that it is easy to volatilize and remove this organic solvent from the adhesive composition of this embodiment by heating etc.

Examples of organic solvents that can dissolve acid-modified polyolefins and can be easily volatilized and removed by heating include aromatic organic solvents such as toluene and xylene, aliphatic organic solvents such as n-hexane, cyclohexane, methyl alcohol, etc. Alicyclic organic solvents such as cyclohexane (MCH), ketone organic solvents such as methyl ethyl ketone (MEK), etc. These organic solvents may be used alone or in combination of two or more.

In addition, other types of organic solvents may be used in combination with the above-mentioned organic solvents that can dissolve the acid-modified polyolefin and are easily volatilized and removed by heating. As other organic solvents, acetate-based organic solvents such as ethyl acetate, n-propyl acetate, and n-butyl acetate are preferably used.

The ratio of the solvent amount of component 5 is preferably 60 mass % to 97 mass %, more preferably 70 mass % to 96 mass %, when the total amount of the adhesive composition of the present embodiment is 100 mass % % or less, more preferably more than 80% by mass and less than 95% by mass. When the ratio of the amount of solvent is within this range, the viscosity of the adhesive composition can be properly maintained, and the thickness of the adhesive layer obtained by applying the adhesive composition and removing the solvent can be easily made appropriate. In addition, the viscosity of the adhesive composition when applied is preferably 200 mPa·s or less at 25°C.

Also, in the adhesive composition of the present embodiment, if it is within the range that does not hinder the effect of the present invention, it may contain a tackifier, a plasticizer, or a polyolefin without an acidic functional group, or it may contain polyolefins other than polyolefins. thermoplastic resin. The type of tackifier is not particularly limited, but for example, natural tackifiers include polyterpene-based resins, rosin-based resins, etc., and petroleum-based tackifiers include those obtained from the decomposition oil fraction of naphtha. Aliphatic (C5) resin, aromatic (C9) resin, copolymer (C5/C9) resin, alicyclic resin, etc. Moreover, the hydrogenated resin obtained by hydrogenating the double bond part of these resins is also mentioned. These tackifiers may be used alone or in combination of two or more.

The types of polyolefins without acidic functional groups and thermoplastic resins other than polyolefins are not particularly limited, but examples include ethylene-vinyl acetate copolymer resins, ethylene-ethyl acrylate copolymer resins, waxes, and the like. Examples of olefin-based thermoplastic elastomers not having a carboxyl group include SEBS (styrene-ethylene-butylene-styrene) and SEPS (styrene-ethylene-propylene-styrene).

Next, the manufacturing method of the laminated body 1 of this embodiment is demonstrated. The manufacturing method of the laminated body 1 of this embodiment includes: a film forming step of forming a film of the adhesive composition film, a lamination step of bonding the metal foil 2 and the resin film 3 together, and heating the film of the adhesive composition to form the adhesive agent. The reaction step of forming the adhesive layer 4 by reacting the composition. The film-forming step, layering step, and reaction step are described below.

The film forming step is a step of applying the adhesive composition of the present embodiment to one or both of the surface of the metal foil 2 and the surface of the resin film 3 to form a film of the adhesive composition of the present embodiment. . The coating method of the adhesive composition is not particularly limited, and examples thereof include printing methods such as gravure printing, offset printing, screen printing, and bar coating printing. However, considering the film thickness of the adhesive composition, it is preferable to use a coating method using gravure printing.

Part or all of the solvent in component 5 may be removed from the film of the adhesive composition. The method of removing the solvent of component 5 from the film of the adhesive composition is not particularly limited, and methods such as heating and decompression can be used, but the method of removing the solvent of component 5 by heating is preferred.

When the solvent of component 5 is removed by heating, it is only necessary to expose the film of the adhesive composition to a specific temperature higher than room temperature. The above-mentioned specific temperature is preferably a temperature below the boiling point of the solvent of component 5. When a plurality of solvents are mixed to form the component 5, the above-mentioned specific temperature is preferably lower than the temperature of the lowest boiling point among the boiling points of the plurality of solvents used as the component 5.

Through these film forming steps, a film of the adhesive composition is formed on one or both of the surface of the metal foil 2 and the surface of the resin film 3 so as to be placed between the metal foil 2 and the resin film 3 The metal foil 2 and the resin film 3 are laminated together as a film of the adhesive composition (lamination step). Through these lamination steps, the metal foil 2, the resin film 3, and the film of the adhesive composition are laminated.

Next, the product obtained in the layering step is heated to react the adhesive composition to form the adhesive layer 4 (reaction step). If described in detail, the component 1, the component 2, and the component 3 in the composition for adhesives react by heating, and crosslink and increase molecular weight. Thereby, the film of the adhesive composition becomes the adhesive layer 4 formed of the adhesive containing the reaction product of the adhesive composition, and the metal foil 2 and the resin film 3 are bonded by the adhesive layer 4 , to become laminate 1. By heating in the reaction step, the reaction of the carboxyl group of the acid-modified polyolefin of component 1 with the isocyanate group of the polyisocyanate compound of component 2 and the isocyanate group of the modified isocyanate compound of component 3 is promoted, and the reaction proceeds .

The heating temperature in the reaction step is not particularly limited as long as the reaction is sufficiently advanced, but it is preferably 30°C or higher, more preferably 40°C or higher, in order to allow the reaction to proceed sufficiently. In addition, in order to suppress changes in the physical properties of the resin film 3 due to heating in the reaction step, the heating temperature in the reaction step is preferably 70°C or lower, more preferably 60°C or lower. Also, the heating time in the reaction step is not particularly limited as long as the reaction is sufficiently advanced, but it is preferably at least 1 hour, more preferably at least 3 hours, and still more preferably at least 6 hours. [Example]

Examples and comparative examples are shown below, and the present invention will be described more specifically. [manufacturing example 1] Into a 1000mL flask equipped with a cooling tube and a stirrer, 75.0 parts by mass of a maleic anhydride graft-modified propylene-butene copolymer, 290 parts by mass of methylcyclohexane as a solvent, and 120 parts by mass of ethyl acetate were charged , stirred at 60° C. for 10 minutes to obtain a liquid resin composition. Subsequently, the resin composition was cooled to room temperature. The solid content concentration of this resin composition was 15.0 mass %. Here, the solid content concentration is the percentage by mass of other components except the solvent with respect to the total mass of the resin composition. The solid content concentration is calculated based on the mass loss rate after vacuum drying at 105° C. for 1 hour.

The acid value of the graft-modified product of the acid-modified polyolefin of Component 1 was 12.6 mg-KOH/g, and its melting point was 80°C. In addition, the copolymerization ratio (molar ratio) of propylene and butene in the graft-modified product is propylene:butene=78:22. In addition, the weight average molecular weight (Mw) of the above-mentioned graft-modified product was 110,000, and the number average molecular weight (Mn) was 58,000. In addition, the melt mass flow rate of the above-mentioned graft-modified product was 29 g/10 minutes, and the heat of fusion was 35 J/g.

The measurement methods of the above-mentioned various properties of the above-mentioned graft-modified product are as follows. (Determination method of acid value) Measured according to the method specified in JIS K0070:1992. (Measurement method of melting point) The melting point is measured in accordance with the method stipulated in JIS K7121 (established in 1987) "Measurement method of transition temperature of plastics". The measurement was performed using a DSC (Differential Scanning Calorimeter) (model DSC-60A) manufactured by Shimadzu Corporation, and the melting peak temperature obtained as a result of differential scanning calorimetry at a heating rate of 10°C/min was set as the "melting point".

More detailed measurement conditions are as follows. That is, the powdery sample of acid-modified polyolefin was heated from room temperature to 180°C at a heating rate of 10°C/min, kept at 180°C for 5 minutes to melt, then cooled to -30°C, and kept at -30°C for 5 minutes. minute. Subsequently, the temperature was raised again at a heating rate of 10° C./minute, and the melting peak temperature detected during the reheating was defined as the melting point.

(Method for Measuring Copolymerization Ratio of Propylene and Butene) Using deuterated chloroform (CDCl ₃ ) as a solvent, carbon 13 nuclear magnetic resonance measurement ( ¹³ C NMR measurement) of acid-modified polyolefin was performed, and the analysis was performed by the following method. The 34.0ppm peak of the ¹³ C NMR spectrum is derived from the carbon of the methyl group of polybutene, and the peak of 27.0ppm~28.0ppm is derived from the carbon of the methylene group of the side chain of polybutene and the methyl group of polypropylene carbon.

Therefore, the copolymerization ratio (mol %) of butene was calculated by dividing the integral ratio of the peak of 34.0 ppm by the integral ratio of the peak of 27.0 ppm to 28.0 ppm and multiplying by 100. Then, the copolymerization ratio (mol %) of propylene was calculated by subtracting the copolymerization ratio of butene calculated as above from 100.

(Measurement method of weight average molecular weight and number average molecular weight) The weight-average molecular weight and number-average molecular weight of the acid-modified polyolefin are weight-average molecular weights and number-average molecular weights in terms of polystyrene measured by gel permeation chromatography. The measurement conditions of the gel permeation chromatography are as follows.

Device name: HPLC unit HSS-2000 manufactured by JASCO Co., Ltd. Column: Showa Denko Co., Ltd. Shodex column LF-805L × 3 pieces (series) Mobile Phase: Tetrahydrofuran Flow rate: 1.0mL/min Detector: RI-2031Plus manufactured by JASCO Co., Ltd. Temperature: 40.0°C Sample volume: sampling loop 100μL Sample concentration: about 0.1% by mass Polystyrene standard substance: Standard SM-105 manufactured by Showa Denko Co., Ltd. (Measurement method of melt mass flow rate) Based on JIS K7210-1:2014, it was measured under the conditions of a temperature of 130°C and a load of 2.16 kg.

[Manufacturing example 2] In a reaction vessel equipped with a cooling pipe, a nitrogen inlet pipe, a thermometer and a stirrer, 470 parts by mass of ethyl acetate, 172 parts by mass of butyl acrylate, 172 parts by mass of 2-ethylhexyl acrylate, 5.6 parts by mass of acrylic acid, 2 , 0.6 parts by mass of 2'-azobis(isobutyronitrile). Then, the internal temperature of the reaction container was raised to 90° C. in a nitrogen stream, and held for 8 hours to polymerize butyl acrylate, 2-ethylhexyl acrylate, and acrylic acid, and then cooled to 30° C. to obtain an acrylic acid copolymer. After the completion of the polymerization, the solid content concentration in the acrylic copolymer solution in the reaction container was measured and found to be 43.1% by mass.

[Manufacturing example 3] Equipped with a three-necked flask equipped with a cooling tube with a calcium chloride tube installed on the top, a thermometer, a dropping funnel, and a stirrer with stirring wings, it was fed into DURANATE (registered trademark) TKA-100 (hexamethylene The isocyanurate body of diisocyanate, isocyanate group concentration: 21.7% by mass) 83.0 parts by mass, and 0.003 parts by mass of dioctyltin dilaurate as a catalyst. And the ethyl acetate solution which melt|dissolved 0.53 mass parts of n-butanols in the ethyl acetate 16.5 mass parts was fed into the dropping funnel, and it prepared for dripping.

Then, the contents of the three-necked flask were started to be stirred by a stirrer, and the inner temperature of the three-necked flask was raised to 70° C. using an oil bath. While continuing to stir with the mixer, drop the above ethyl acetate solution into the three-necked flask from the dropping funnel over 60 minutes to react the isocyanurate body of hexamethylene diisocyanate with n-butanol. At this time, the dropwise addition was performed while controlling the internal temperature of the three-necked flask to be 70°C or higher and 75°C or lower. After the addition of the ethyl acetate solution was completed, the reaction was continued for 1 hour, and the reaction solution in the three-necked flask was analyzed by gas chromatography. Then, after confirming that the peak of n-butanol was no longer observed, the reaction was terminated.

By this reaction, the isocyanurate body (polyisocyanate compound) of hexamethylene diisocyanate is obtained, and the hydroxyl group of n-butanol is added to the isocyanurate body of hexamethylene diisocyanate. A mixture of addition reactants (modified isocyanate compounds with urethane bonds) generated from isocyanate groups. The solid content concentration of the reaction liquid in the three-necked flask was 83.5% by mass.

In this mixture, the total number of moles of isocyanate groups in the isocyanurate body (polyisocyanate compound) of hexamethylene diisocyanate is defined as Ia, and the above-mentioned addition reaction product (modified isocyanate compound) is When the total number of moles of the isocyanate groups possessed is Ib, and the total moles of the modified groups (urethane bonds) possessed by the above-mentioned addition reaction product (modified isocyanate compound) is represented as H, H is relative to The ratio H/(Ia+Ib+H) of the total moles of Ia, Ib, and H was 0.017.

[Manufacturing example 4~16] Except having changed the usage-amount of the isocyanurate body (polyisocyanate compound) of hexamethylene diisocyanate and the kind and usage-amount of a monohydric alcohol to what was described in Table 1, the same operation as Production Example 3 was performed. Thereby, the isocyanurate body (polyisocyanate compound) containing hexamethylene diisocyanate and the isocyanurate body which added the hydroxyl group of the monohydric alcohol to hexamethylene diisocyanate are obtained. A reaction solution of a mixture of addition reactants (modified isocyanate compounds) generated by isocyanate groups. In addition, the solid content concentration of the reaction solution in the three-necked flask was 83.5% by mass in any production example.

[Examples 1-11 and Comparative Examples 1-10] The resin composition of Production Example 1 or the acrylic acid copolymer solution of Production Example 2, the isocyanurate body of hexamethylene diisocyanate or the reaction solution of Production Examples 3 to 16, and the dibutyltin dilaurate of the reaction catalyst Salt, solvent methylcyclohexane, and ethyl acetate were mixed to obtain adhesive compositions of Examples 1-11 and Comparative Examples 1-10. The quality of the mixed components is listed in Table 2.

In these adhesive compositions, the ratio H/(Ia+Ib+H) of H to the total number of moles of Ia, Ib, and H is as described in Table 2. In addition, in these adhesive compositions, the total molar number of the carboxyl groups possessed by the acid-modified polyolefin in Production Example 1 or the acrylic copolymer in Production Example 2 is C, and the isocyanate contained in the polyisocyanate compound is When the total number of moles of Ia and the total number of moles of isocyanate groups possessed by the modified isocyanate compound is taken as Ib, the ratio of the total number of moles of Ia and Ib to C is (Ia+Ib)/C As recorded in Table 2.

Next, using the adhesive composition of Examples 1-11 and Comparative Examples 1-10, the test piece of a laminated body was produced. Next, a method for producing a test piece of a laminate will be described. Prepare an aluminum foil (width: 10 cm, thickness: 40 μm) with an anti-corrosion treatment (chemical conversion treatment) layer on the surface, apply the composition for adhesive on the surface of the aluminum foil, and form a film of the composition for adhesive on the surface of the aluminum foil. Coating of the adhesive composition was performed using a bar coater. In addition, the coating amount of the adhesive composition was 2 g/m ² .

The aluminum foil formed with the film of the adhesive composition was placed in a hot air drying oven at 80° C. for 20 seconds, and the solvent in the adhesive composition was evaporated for drying. An unstretched polypropylene film with a thickness of 80 μm was prepared as a heat-adhesive resin film, and the unstretched polypropylene film was placed between the unstretched polypropylene film and the aluminum foil in a hot air drying oven. The film is overlaid with aluminum foil and laminated using a rubber roller. Thereby, a sheet-shaped laminated film obtained by laminating the unstretched polypropylene film, the film of the adhesive composition, and the aluminum foil was obtained.

Next, the obtained sheet-shaped laminated film was placed in a hot-air circulation oven at a temperature of 40° C. for one week. By this heat treatment, the reaction of the adhesive composition proceeds, and the film of the adhesive composition becomes an adhesive layer formed of an adhesive containing the reaction product of the adhesive composition, and the adhesive layer is obtained. A laminate of unstretched polypropylene film and aluminum foil. The obtained laminate was taken out from the hot-air circulation oven and cut to produce short strip-shaped test pieces with a width of 15 mm.

With regard to the obtained test piece, the peel strength between the unstretched polypropylene film and the aluminum foil was measured at a temperature of 85° C., and the adhesiveness of the adhesive agent at high temperature was evaluated. The peel strength is measured by the T-peel test according to the method stipulated in JIS K6854-3:1999. The stretching speed was 100 mm/min.

As shown in Table 2, the test pieces of Examples 1 to 11 have excellent peel strength even at a high temperature of 85°C because the ratio H/(Ia+Ib+H) is in the range of more than 0 and less than 0.5. , it can be seen that the adhesive agent at high temperature has excellent adhesiveness. In contrast, the test pieces of Comparative Examples 1 to 4 had lower peel strengths at high temperatures than those of Examples 1 to 11 because the ratio H/(Ia+Ib+H) was outside the range of more than 0 and not more than 0.5. It can be seen that the adhesiveness of the adhesive at high temperature is insufficient.

And, Comparative Examples 5-7 are by reducing the usage amount of polyisocyanate compound (isocyanurate body of hexamethylene diisocyanate), and make the number of the isocyanate group contained in the adhesive composition be less than Example of Comparative Example 1. Regarding Examples 1 to 11, by substituting part of the polyisocyanate compound (isocyanurate body of hexamethylene diisocyanate) with a modified isocyanate compound, the same composition as Comparative Examples 5 to 7 was used for the adhesive agent. The number of isocyanate groups contained in the compound is less than that of Comparative Example 1.

However, the peel strength of the test pieces of Examples 1-11 at high temperature is higher than that of Comparative Examples 5-7, and the adhesiveness of the adhesive agent at high temperature is excellent. From the results, it can be seen that in order to improve the adhesiveness of the adhesive at high temperature, not only must the number of isocyanate groups contained in the adhesive composition be controlled, but the adhesive composition must also contain a modified isocyanate compound.

1: laminated body 2: metal foil 3: Resin film 4: Adhesive layer

[ Fig. 1 ] is a sectional view illustrating an embodiment of a laminate of the present invention.

1: laminated body

2: metal foil

3: Resin film

4: Adhesive layer

Claims (9)

An adhesive composition for obtaining an adhesive for bonding a metal foil and a resin film, comprising: (Component 1) Acid-modified polyolefin having carboxyl groups, (Component 2) A polyisocyanate compound having p (p is an integer greater than 2) isocyanate groups bonded to the core, (Component 3) On the mother core having the same structure as the polyisocyanate compound of the aforementioned component 2, there are q (q is an integer of 1 or more) isocyanate groups and r (r is an integer of 1 or more) bonded to the core of the polyisocyanate compound, and q+r is satisfied =p) Modified isocyanate compounds of compounds with modifying groups, (Component 4) a reaction catalyst that promotes the reaction of the carboxyl group possessed by the aforementioned component 1 and the isocyanate group possessed by the aforementioned component 2 and the aforementioned component 3, and (ingredient 5) solvent, The aforementioned modifying group possessed by the modified isocyanate compound of the aforementioned component 3 is obtained by reacting the aforementioned functional group having active hydrogen of the isocyanate group bonded to the aforementioned mother core and the active hydrogen compound having a functional group having active hydrogen the foundation of which was born, Let the total number of moles of the isocyanate groups of the polyisocyanate compound of the aforementioned component 2 be Ia, the total molar number of the isocyanate groups of the modified isocyanate compound of the aforementioned component 3 be set as Ib, and the aforementioned component 3 When the total number of moles of the aforementioned modifying groups possessed by the modified isocyanate compound is H, the ratio H/(Ia+Ib+H) of H to the total number of moles of Ia, Ib, and H exceeds 0 and 0.5 the following. The adhesive composition according to claim 1, wherein the functional group having active hydrogen is at least any one of hydroxyl and carboxyl. The adhesive composition according to claim 1, wherein the active hydrogen compound is at least one compound selected from monovalent alcohols and monovalent carboxylic acids. The adhesive composition according to any one of claims 1 to 3, wherein the aforementioned polyisocyanate compound is a saturated aliphatic polyisocyanate. The adhesive composition according to any one of claims 1 to 3, wherein the aforementioned polyisocyanate compound is selected from isocyanurate bodies of saturated aliphatic polyisocyanates and allophanate bodies of saturated aliphatic polyisocyanates at least one of the compounds. The adhesive composition according to any one of claims 1 to 5, wherein the acid-modified polyolefin is an acid-modified polyolefin containing one or more of propylene, ethylene, and butene as a monomer. The adhesive composition according to any one of claims 1 to 6, wherein the acid-modified polyolefin contains an acid-modified product in which the polyolefin is modified with at least one selected from ethylenically unsaturated carboxylic acids and their anhydrides . A laminate comprising a metal foil, a resin film, and an adhesive layer for bonding the metal foil and the resin film between the metal foil and the resin film, wherein the adhesive layer is composed of The adhesive agent according to any one of claims 1 to 7 is formed of the adhesive agent of the reaction product of the composition. The laminate according to claim 8, wherein the metal foil is an aluminum foil, and the resin film is a heat-adhesive resin film.

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