JP2016175973A - Adhesive for lamination and laminated body using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive for lamination capable of reinforcing the gas barrier function of various vapor-deposited films by the imparting of a gas barrier function to an adhesive layer itself, and simultaneously having satisfactory adhesive strength to various vapor-deposited layers, and a gas barrier multilayer film using the same.SOLUTION: An adhesive for lamination comprises: a polyester or polyester polyurethane resin (A) having two or more hydroxy groups in one molecule as functional groups and also obtained, as the polyvalent carboxylic acid of a monomer component composing polyester, by using ortho-oriented aromatic group dicarboxylic acid or the anhydride thereof and polyisocyanate (B) containing diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate and their derivatives.SELECTED DRAWING: None

Description

  The present invention relates to a laminating adhesive having a gas barrier function, and a gas barrier laminate using the same.

  Packaging materials such as foods and beverages often require gas barrier properties such as water vapor and oxygen barriers to protect the contents. As a method for providing a gas barrier to a packaging material, a method of applying a gas barrier coating to a stretched film or a method of providing a gas barrier resin on a layer in a multilayer film by coextrusion is widely used. The method is an excellent method that can easily provide a barrier function regardless of the type of gas.

There are a stretched film and an unstretched film as the film for vapor deposition. Particularly, in the case of a metal vapor deposited film such as aluminum, both kinds of substrates are often used. However, since the thickness of these vapor deposition layers is generally as thin as 10 to 50 nm, pinholes are likely to occur, and the gas barrier function may not be stable. In particular, when the base film is an unstretched film, the gas barrier is particularly unstable because the film is easily stretched compared to the stretched film and the base film itself has poor gas barrier properties. Therefore, it is difficult to use a film deposited on an unstretched film for packaging that requires stable gas barrier properties. On the other hand, a transparent vapor deposition film provided with a vapor deposition layer of a metal oxide such as silica or alumina as a gas barrier layer is hardly mass-produced with an unstretched film because the vapor deposition layer is more brittle than a metal. For this reason, vapor deposition on stretched films with high dimensional stability is mainly used, but these films still have a problem that the barrier performance varies due to cracks and pinholes.

In order to solve the above-mentioned problem that the gas barrier is unstable, it is widely performed particularly in transparent deposition to protect the deposited layer with an overcoat layer. This is because transparent vapor deposition generally places a fragile metal oxide layer on the film, so that the barrier performance is not stable without an overcoat layer. For example, Patent Document 1 and Patent Document 2 disclose an overcoat technique for transparent vapor deposition, such as an inorganic oxide layer, a so-called transparent vapor deposition layer, a water-soluble polymer, (a) one or more metal alkoxides, (b 1) a gas barrier coating layer formed by applying a hydrolyzate of one or more metal alkoxides, or (c) an aqueous solution containing at least one tin chloride, or a gas barrier coating solution containing a water / alcohol mixed solution as a main component. A transparent gas barrier laminate having the following is described. The overcoat layer used in these technologies generally uses a water-soluble polymer, so it has poor coating dryness and includes a sol-gel process that is difficult to control the reaction, making it difficult to manage and reuse the overcoat solution. However, the overcoat process has a complicated problem. Furthermore, it is unavoidable that the packaging cost increases by providing an overcoat layer essentially.

When laminating a vapor-deposited film as a different method to a multilayer film and using a laminating adhesive having a gas barrier function, the above-mentioned overcoat layer and laminating adhesive have the function of an adhesive. High cost of packaging can be avoided. However, in general, the vapor deposition surface of the vapor deposition film has a lower surface tension than the film surface subjected to corona treatment which is usually used for lamination. Therefore, in a multilayer film having a vapor deposition film, the laminate strength may be poor even when an adhesive that does not have a gas barrier function is used. In order to solve such a phenomenon, for example, in Patent Document 3, a polyfunctional polyurethaneurea polyol resin composition containing phosphoric acids or derivatives thereof in the range of 0.01 to 0.3% by weight is improved in initial adhesion to inorganic substances. However, there is no description that the adhesive layer itself has gas barrier properties to improve the gas barrier function of the deposited film.

JP 2012-101505 A JP 2012-250470 A JP 2000-7748 A

  The problem to be solved by the invention is that the adhesive layer itself has a gas barrier function to reinforce the gas barrier function of various deposited films, and at the same time, an adhesive for laminating that has good adhesive strength to various deposited layers, and It is to provide a gas barrier multilayer film used.

In the adhesive for laminating containing the polyester or polyester polyurethane resin (A) and the polyisocyanate (B), the present inventors
The polyester or polyester polyurethane resin (A) has two or more hydroxyl groups in one molecule as a functional group, and an ortho-oriented aromatic dicarboxylic acid or an anhydride thereof as a polyvalent carboxylic acid as a monomer component constituting the polyester Is a polyester or polyester polyurethane resin (A) obtained using
Adhesion with an Al vapor-deposited film or a transparent vapor-deposited film using an adhesive for laminating, wherein the polyisocyanate (B) is a polyisocyanate (B) containing diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, and derivatives thereof The inventors have found that the strength and the function of strengthening the gas barrier can be compatible, and have completed the present invention.

In addition, the present inventors bonded a layer selected from an inorganic layer, a metal foil layer, a metal vapor-deposited film layer, and a transparent vapor-deposited film layer and another layer through an adhesive layer obtained by the adhesive laminate adhesive. It has been found that a laminate having the above-described configuration becomes a laminate having both an excellent gas barrier function, adhesive strength, and seal strength.

  According to the present invention, it is possible to provide a laminated adhesive for a vapor deposition film, which is excellent in ability to improve gas barrier properties and water vapor barrier properties in various vapor deposition films and aluminum foils, and excellent in adhesive strength between the film and other films. Can do. Moreover, according to this invention, the laminated body containing this contact bonding layer can be provided.

That is, the present invention includes the following items.
1. In the laminating adhesive containing the polyester or polyester polyurethane resin (A) and the polyisocyanate (B),
The polyester or polyester polyurethane resin (A) has two or more hydroxyl groups in one molecule as a functional group, and an ortho-oriented aromatic dicarboxylic acid or an anhydride thereof as a polyvalent carboxylic acid as a monomer component constituting the polyester Is a polyester or polyester polyurethane resin (A) obtained using
An adhesive for laminating, wherein the polyisocyanate (B) is diisocyanate diisocyanate, polymeric diphenylmethane diisocyanate, and polyisocyanate (B) containing derivatives thereof;
2. 1. The content of diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, and derivatives thereof is 10% by mass or more in the adhesive solid content for lamination. Adhesive for laminating according to
3. The resin (A) is a group consisting of a polyvalent carboxylic acid component containing at least one ortho-oriented aromatic dicarboxylic acid or anhydride thereof, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. 1. A polyester polyol obtained by polycondensation of a polyhydric alcohol component containing at least one selected. Or 2. Laminate adhesive according to
4). Ortho-oriented aromatic dicarboxylic acid or its anhydride is orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid Or an anhydride thereof, and at least one selected from the group consisting of 2,3-anthracene dicarboxylic acid or an anhydride thereof. ~ 3. Laminate adhesive according to any one of
5. Further, it contains a plate-like inorganic compound. ~ 4. Laminate adhesive according to any one of
6.1. ~ 5. A laminate obtained by using the laminate adhesive according to any one of
7.1. ~ 5. A layer selected from an inorganic layer, a metal foil layer, a metal vapor-deposited film layer, and a transparent vapor-deposited film layer and another layer are bonded via an adhesive layer obtained by the laminate adhesive according to any one of 6 . A laminate according to
8.6. Or 7. A packaging material using the laminate described in 1.

This will be described in detail below.
[Diphenylmethane diisocyanate]
The agent used as an adhesive for lamination in the present invention needs to contain a compound having a diphenylmethane diisocyanate (MDI) skeleton as the polyisocyanate (B). Diphenylmethane diisocyanate includes three isomers of 2,2′-MDI, 2,4′-MDI and 4,4′-MDI, any of which may be used. Further, polymeric diphenylmethane diisocyanate, which is a high molecular weight type polyisocyanate, may be contained. Specific examples of products commercially available as these compounds or mixtures include Millionate MT, Millionate MR-100, Millionate MR-200, Millionate MR-400, Coronate 1160, Coronate C-1130, BASF manufactured by Nippon Polyurethane. Lupranate MI, Lupranate MB 5S, Lupranate MB 9S, Lupranate M-12S, Lupranate M-20S, Cosmonate LL, Cosmonate M-30, Cosmonate-50, Cosmonate M-200DS, Sumitomo Examples include chemical Sumijour 44V10, Sumijoule 44V20, Bayer, Death Module VL50, and the like. Hereinafter, diphenylmethane diisocyanate may be referred to as MDI.

[Number of functional groups of diphenylmethane diisocyanate and polymeric diphenylmethane diisocyanate]
The number of functional groups of the isocyanate group of diphenylmethane diisocyanate and polymeric diphenylmethane diisocyanate used in the present invention is not limited as long as it is 2 or more, but as a premise for sufficiently carrying out the curing reaction, 2.5 or more, preferably trifunctional or more. preferable. In particular, it is preferable to use a highly viscous material among polymeric diphenylmethane diisocyanates because the number of functional groups increases.

[Estimation of content and functional expression of diphenylmethane diisocyanate and polymeric diphenylmethane diisocyanate]
By containing diphenylmethane diisocyanate and polymeric diphenylmethane diisocyanate in the adhesive of the present invention, it is possible to achieve both an adhesive force with various deposited films and aluminum foil and a gas barrier improving function. Accordingly, it is preferable that the content of diphenylmethane diisocyanate in the adhesive is a certain level or more. Specifically, it is preferable that 10% by mass or more of the solid content of the cured adhesive is an MDI-derived component, more preferably 15% by mass or more, and particularly preferably 20% by mass or more. When the MDI component is in the adhesive cured product, the surface tension of the cured film tends to be lower than other curing agent components. For this reason, it is presumed that the surface tension is lower than that of a general corona-treated film, and the affinity to various deposited films and aluminum foils is enhanced, and the adhesive strength and the reinforcement of the gas barrier can be obtained.

  In the present invention, in addition to diphenylmethane diisocyanate, other polyisocyanate compounds may be used in combination as long as the effects of the present invention are not impaired. As the polyisocyanate compound used at this time, known general compounds can be widely used. In particular, it is preferable to contain an aromatic ring or an aliphatic ring in a part of the skeleton from the viewpoint of a gas barrier improving function. For example, as an isocyanate having an aromatic ring, toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, and as an isocyanate having an aliphatic ring, hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, isophorone diisocyanate, norborn diisocyanate. Or trimers of these isocyanate compounds, and excess amounts of these isocyanate compounds, such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, and triethanolamine. Molecularly active hydrogen compounds or various polyester polyols, polyethers Le polyols include terminal isocyanate group-containing compounds obtained by reacting with such polymer active hydrogen compound polyamides.

(Polyester polyol)
In the present invention, a material that causes a curing reaction with diphenylmethane diisocyanate is a polyester or polyester polyurethane resin having two or more hydroxyl groups in one molecule as a functional group, and an ortho-oriented fragrance as a polyvalent carboxylic acid of a polyester constituent monomer component. Polyester or polyester polyurethane resin using a group dicarboxylic acid or its anhydride is used. At this time, the polyester as the main skeleton is used by polycondensation of a polyvalent carboxylic acid component and a polyhydric alcohol component.

[Polycarboxylic acid component]
The polyvalent carboxylic acid component of the present invention is characterized by containing at least one of ortho-oriented aromatic dicarboxylic acids or anhydrides thereof.
The aromatic polyvalent carboxylic acid in which the carboxylic acid is substituted in the ortho position or its anhydride include orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its An anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, 2,3-anthracene carboxylic acid or its anhydride, etc. are mentioned. These compounds may have a substituent on any carbon atom of the aromatic ring. Examples of the substituent include chloro group, bromo group, methyl group, ethyl group, i-propyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, methylthio group, phenylthio group, cyano group, nitro group, amino group, Examples thereof include a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group, and a naphthyl group. Moreover, when it is the polyester polyol whose usage rate with respect to all these polycarboxylic acid components is 70-100 mass%, in addition to the improvement effect of barrier property being high, it is excellent in the solvent solubility essential as a dry laminate type adhesive material. This is particularly preferable.

In the present invention, other polyvalent carboxylic acid components may be copolymerized as long as the effects of the invention are not impaired. Specifically, as the aliphatic polyvalent carboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, etc., as the unsaturated bond-containing polyvalent carboxylic acid, maleic anhydride, maleic acid, Fumaric acid etc., 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid etc. as alicyclic polyvalent carboxylic acid, terephthalic acid, isophthalic acid, pyromellitic as aromatic polyvalent carboxylic acid Acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, diphenic acid and its anhydride, 1,2-bis ( Phenoxy) ethane-p, p'-dicarboxylic acid and anhydrides or ester-forming derivatives of these dicarboxylic acids; p- Dorokishi benzoic acid, can be used in p-(2-hydroxyethoxy) benzoic acid and alone or in mixture of two or more polybasic acids such as ester-forming derivatives of these dihydroxy carboxylic acids. Of these, succinic acid, 1,3-cyclopentanedicarboxylic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalic acid, and diphenic acid are preferred from the viewpoints of organic solvent solubility and gas barrier properties.

[Polyhydric alcohol component]
The polyhydric alcohol component used in the present invention is not particularly limited as long as it can synthesize polyester exhibiting gas barrier filling performance, but ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, cyclohexanedimethanol, and 1,3-bis. It is preferable to contain a polyhydric alcohol component containing at least one selected from the group consisting of hydroxyethylbenzene. Among them, the smaller the number of carbon atoms between oxygen atoms, the more likely that the molecular chain will not be excessively flexible and oxygen is less likely to permeate. Therefore, it is most preferable to use ethylene glycol as the main component.

In the present invention, the above-mentioned polyhydric alcohol component is preferably used, but other polyhydric alcohol components may be copolymerized within the range not impairing the effects of the present invention. Specifically, as the diol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene Glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol are trihydric or higher alcohols such as glycerol, trimethylolpropane, trimethylolethane, tris (2-hydroxyethyl) isocyanurate, 1,2,4-butane. Examples include triol, pentaerythritol, dipentaerythritol and the like. In particular, among trivalent alcohols, glycerol and polyester combined with tris (2-hydroxyethyl) isocyanurate have good solubility in organic solvents due to the moderately high crosslinking density derived from the branched structure. The barrier function is also excellent and is particularly preferably used.

(Effect of having orthophthalic acid and its anhydride in the skeleton)
Orthophthalic acid and its anhydride have an asymmetric structure in the skeleton. Therefore, it is presumed that the rotation of the molecular chain of the resulting polyester is suppressed, and thus it is presumed that the gas barrier property is excellent. Further, it is presumed that due to this asymmetric structure, it exhibits non-crystallinity, imparts sufficient substrate adhesion, and is excellent in adhesion and gas barrier properties. Furthermore, when used as a dry laminate adhesive, the solvent solubility, which is essential, is also high, so that it has excellent handling characteristics.

(Example of synthesis method of resin (A))
When the resin (A) is a polyester terpolyol, it can be obtained by a known polyester production method. Specifically, it can be synthesized by a production method in which the reaction is carried out while removing produced water from the system at a reaction temperature of 200 to 220 ° C. in the presence of a catalyst.

  As a specific example, an aromatic polyvalent carboxylic acid in which the carboxylic acid is substituted in the ortho position or an anhydride thereof, and a polyhydric alcohol component are charged together, and then heated while stirring and mixed to dehydrate. Allow condensation reaction. 1 mgKOH / g or less by the acid value measurement method described in JIS-K0070, and the hydroxyl value ZmgKOH / g obtained by the hydroxyl value measurement method described in JIS-K0070 is the value on the right side of the following formula (e) (mgKOH / The target polyester polyol can be obtained by continuing the reaction until it falls within ± 5% of g).

(In formula (e), Mn represents a set number average molecular weight of a predetermined trifunctional polyester resin.)

  Alternatively, each raw material may be reacted in multiple stages. Moreover, you may prepare so that a hydroxyl value may enter into less than +/- 5%, adding the diol component which volatilized at reaction temperature.

  Examples of the catalyst used in the reaction include acids such as tin-based catalysts such as monobutyltin oxide and dibutyltin oxide, titanium-based catalysts such as tetra-isopropyl-titanate and tetra-butyl-titanate, and zirconia-based catalysts such as tetra-butyl-zirconate. A catalyst is mentioned. It is preferable to use a combination of the titanium-based catalyst such as tetra-isopropyl-titanate and tetra-butyl-titanate, which has high activity for ester reaction, and the zirconia catalyst. The catalyst amount is used in an amount of 1-1000 ppm, more preferably 10-100 ppm, based on the total mass of the reaction raw material used. If it is less than 1 ppm, it is difficult to obtain an effect as a catalyst, and if it exceeds 1000 ppm, the subsequent urethanization reaction tends to be inhibited.

  The number average molecular weight of these resins (A) is particularly preferably from 450 to 15,000 because a crosslinking density with an excellent balance between adhesive ability and gas barrier ability can be obtained. More preferably, the number average molecular weight is 500 to 5,000. Further, as the curing agent, polyisocyanate described below is most preferable, an appropriate reaction time can be imparted, and the adhesive strength and gas barrier ability are particularly excellent. If the molecular weight is less than 450, the cohesive force of the adhesive at the time of coating becomes too small, causing problems such as film displacement during lamination or floating of the laminated film, and conversely if the molecular weight is higher than 15000, The problem is that the viscosity at the time of construction is too high to be applied, and that the lamination is impossible due to low adhesiveness. The number average molecular weight was obtained by calculation from the obtained hydroxyl value and the number of functional groups of the designed hydroxyl group.

  The resin (A) used in the present invention preferably has a glass transition temperature in the range of -30 ° C to 80 ° C. More preferably, it is 0 degreeC-60 degreeC. More preferably, it is 25 degreeC-60 degreeC. When the glass transition temperature is too higher than 80 ° C., the flexibility of the polyester polyol near room temperature is lowered, and thus the adhesiveness to the substrate may be deteriorated due to poor adhesion to the substrate. On the other hand, when the temperature is too lower than −30 ° C., sufficient gas barrier properties may not be obtained due to the intense molecular motion of the polyester polyol near normal temperature.

  Furthermore, you may use the polyester polyurethane polyol and polyether polyurethane polyol which made the number average molecular weight 1000-30000 by urethane expansion | extension by reaction with resin (A) with a diisocyanate compound as an adhesive agent. Since the polyol has a certain molecular weight component and a urethane bond, the polyol has excellent gas barrier properties, excellent initial cohesive force, and is further excellent as an adhesive used during lamination. Moreover, the terminal can be made into an isocyanate group by making the ratio of the hydroxyl group and the isocyanato group in the resin (A) and the diisocyanate compound excessive, and this can be made into an isocyanate group. May be used as

[Additives to adhesives]
(Plate-like inorganic compound)
In the adhesive of the present invention, a plate-like inorganic compound may be contained.
When a plate-like inorganic compound is used in the present invention, it has an effect of improving part of the laminate strength and gas barrier properties.

  When a plate-like inorganic compound is used in combination, the barrier property is improved due to the plate shape. The charge between the layers of the plate-like inorganic compound does not greatly affect the barrier property directly, but the dispersibility to the resin composition is greatly inferior with the ionic inorganic compound or the swellable inorganic compound with respect to water, and the amount added is increased. As a result, the resin composition becomes thicker and thixotropic. On the other hand, in the case of being uncharged (nonionic) or non-swelling with respect to water, even if the addition amount is increased, it is difficult to become thickened or thixotropic, so that the coating suitability can be ensured. Examples of the plate-like inorganic compound used in the present invention include, for example, hydrous silicate (phyllosilicate mineral etc.), kaolinite-serpentine clay mineral (halloysite, kaolinite, ende Light, dickite, nacrite, etc., antigolite, chrysotile, etc.), pyrophyllite-talc group (pyrophyllite, talc, kerorai, etc.), smectite group clay minerals (montmorillonite, beidellite, nontronite, saponite, hectorite, Sauconite, stevensite, etc.), vermiculite group clay minerals (vermiculite etc.), mica or mica group clay minerals (muscovite, phlogopite etc. mica, margarite, tetrasilic mica, teniolite, etc.), chlorite group (kukeite, sudite) , Clinocroix, sha Site Nimaito etc.), hydrotalcite, tabular barium sulfate, boehmite, and aluminum polyphosphate and the like. These minerals may be natural clay minerals or synthetic clay minerals. A plate-like inorganic compound is used individually or in combination of 2 or more types. The aspect ratio of the plate-like inorganic compound, the content in the coating material, the particle diameter, and the particle size distribution are not particularly limited as long as a barrier improving function and blocking resistance can be imparted.

  In the case of using a plate-like inorganic compound, a known dispersion method can be used as a method of dispersing in an adhesive mainly composed of polyester. For example, an ultrasonic homogenizer, a high-pressure homogenizer, a paint conditioner, a ball mill, a roll mill, a sand mill, a sand grinder, a dyno mill, a disperse mat, a nano mill, an SC mill, a nanomizer, and the like can be mentioned, and even more preferably, a high shear force is generated. Examples of equipment that can be used include Henschel mixer, pressure kneader, Banbury mixer, planetary mixer, two-roll, three-roll. One of these may be used alone, or two or more devices may be used in combination. The object to disperse these plate-like inorganic compounds is preferably on the resin (A) side, and when introduced on the polyisocyanate (B) side, there is a risk of reacting with the hydroxyl group of the filler and causing gelation.

(Acid anhydride)
In the present invention, a known acid anhydride can be used in combination as an additive as a method for improving the acid resistance of the coating material layer. Examples of the acid anhydride include phthalic acid anhydride, succinic acid anhydride, het acid anhydride, hymic acid anhydride, maleic acid anhydride, tetrahydrophthalic acid anhydride, hexahydraphthalic acid anhydride, tetraprom phthalic acid Anhydride, tetrachlorophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenotetracarboxylic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 5- (2 , 5-oxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, styrene maleic anhydride copolymer and the like. It is preferable that a non-petroleum-derived component is contained as a raw material for these acid anhydrides because the ratio of the non-petroleum-derived component can be increased. An example of such a compound is succinic anhydride.

(Gas capture component)
Moreover, you may add the material which has a gas trap function further as needed. Examples of materials having an oxygen scavenging function include hindered phenols, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, pyrogallol and other low molecular organic compounds that react with oxygen, cobalt, manganese, nickel, iron, Examples include transition metal compounds such as copper. Examples of the material having a water vapor capturing function include materials such as silica gel, zeolite, activated carbon, and calcium carbonate. In addition to these, it is possible to add a capture component of the target gas to be blocked.

(Other ingredients)
The adhesive of the present invention may contain various additives. Examples of additives include inorganic fillers such as silica, alumina, aluminum flakes and glass flakes, and dispersants, stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, etc.), plastics when inorganic materials are used. Examples thereof include agents, antistatic agents, lubricants, antiblocking agents, colorants, leveling agents, slip improvers and the like.

(Usage of the laminate adhesive of the present invention)
The method of using the laminate adhesive of the present invention is generally based on coating and laminating various resin films on a substrate.

(Films and sheets to be used)
The film for lamination used as the substrate is not particularly limited, and a thermoplastic resin film can be appropriately selected according to a desired application. For food packaging, for example, PET film, polystyrene film, polyamide (nylon) film, polyacrylonitrile film, polyethylene film (LLDPE: linear low density polyethylene film, HDPE: high density polyethylene film) and polypropylene film (CPP: unstretched) Polyolefin film such as polypropylene film and OPP (biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, and the like. These may be subjected to stretching treatment. As the stretching treatment method, it is common to perform simultaneous biaxial stretching or sequential biaxial stretching after the resin is melt-extruded by extrusion film forming method or the like to form a sheet. Further, in the case of sequential biaxial stretching, it is common to first perform longitudinal stretching and then perform lateral stretching. Specifically, a method of combining longitudinal stretching using a speed difference between rolls and transverse stretching using a tenter is often used. In addition to these resin films, a sheet-like material such as paper or cloth may be used as the substrate.

  Moreover, you may perform various surface treatments, such as a flame treatment and a corona discharge treatment, as needed so that the adhesive layer without defects, such as a film | membrane piece and a repellency, may be formed in the film surface.

(Film with inorganic layer)
The effect of the present invention is to provide an adhesive having a strong adhesive strength and a high barrier reinforcing function when various films such as a metal foil, a metal deposited film, and a transparent deposited film are laminated. As the metal foil used at this time, a metal foil such as an aluminum foil, a zinc foil, or a tin foil can be used. In particular, aluminum foil is preferred because it is widely used in terms of price and supply. Moreover, as a metal vapor deposition film, what vapor-deposited metals, such as aluminum, tin, zinc, magnesium, on the said base film is used. These metals are not particularly limited, but aluminum can be widely used in terms of price and supply. Moreover, as a transparent vapor deposition film, the film which vapor-deposited aluminum oxide (alumina), silicon oxide (silica), tin oxide, zinc oxide, magnesium oxide etc. on the said base film can be illustrated. Of these, aluminum oxide, silicon oxide, and binary deposits thereof are preferably used from the viewpoint of price and supply.

  In the case where the film having an inorganic layer is a metal vapor-deposited film or a transparent vapor-deposited film, the vapor-deposition method may be produced by any known method, such as a chemical vapor deposition (CVD) method, a physical vapor deposition (PVD) method, Etc. can be illustrated. These films may or may not have an overcoat layer. However, when a film without an overcoat layer is used, the effects of improving the adhesive force and improving the gas barrier of the present invention are particularly remarkable.

(Usage of the laminate adhesive of the present invention)
The laminate adhesive of the present invention is suitable for use in a dry lamination method and a solventless method. For both dry lamination and solvent-free methods, coating lamination is performed by a known and conventional method. Moreover, it is set as a multilayer film by performing processes, such as aging, as needed.

(Gas component types that can block permeation)
When the gas barrier function of the deposited film is enhanced by the adhesive of the present invention, the gas that can be blocked is oxygen, water vapor, alcohol components such as methanol, ethanol and propanol, phenols such as phenol and cresol, and low molecular compounds. Aroma components such as soy sauce, sauce, miso, menthol, methyl salicylate, coffee, cocoa shampoo, rinse, and the like can be exemplified.

  Next, the present invention will be specifically described with reference to examples and comparative examples. Unless otherwise indicated, “part” and “%” are based on mass.

Production Example 1 Production Method of Polyester Polyol Resin GlyEGoPA900 (EPF-982) Consisting of Phthalic Anhydride, Ethylene Glycol, and Glycerol A polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, moisture separator, etc. Is charged with 1036.84 parts of phthalic anhydride, 391.81 parts of ethylene glycol, 184.18 parts of glycerol, and 0.03 part of titanium tetraisopropoxide, and gradually the upper temperature of the rectifying tube does not exceed 100 ° C. The internal temperature was kept at 220 ° C. When the acid value became 2 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol resin (A) having a number average molecular weight of 900.

(Production Example 2) Production method of polyester polyol GlyEGoPA1200 (ENF-605) composed of phthalic anhydride, ethylene glycol and glycerol In a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, moisture separator, etc. , 368.84 parts of phthalic anhydride, 325.87 parts of ethylene glycol, 276.27 parts of glycerol, and 0.03 part of titanium tetraisopropoxide, and gradually adjust the rectifier top temperature not to exceed 100 ° C. The internal temperature was kept at 220 ° C. by heating. When the acid value reached 2 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol resin (A) having a number average molecular weight of 1200.

(Production Example 3) Production method of polyester polyol EGoPA3000 comprising phthalic anhydride and ethylene glycol 148.1 parts of phthalic anhydride in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, moisture separator, etc. Then, 72.1 parts of ethylene glycol and 0.03 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 10 mgKOH / g or less, heating was continued under reduced pressure at 100 torr, and when the acid value became 3 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol having a number average molecular weight of 3000.

Production Example 4 Production Method of Polyester Polyol Resin EGoPA900 Consisting of Phthalic Anhydride and Ethylene Glycol In a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, snider tube, condenser, 148.1 parts of phthalic anhydride, ethylene glycol 82 .9 parts and 0.05 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the upper temperature of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol having a number average molecular weight of 900.

Production Example 5 Production Method of Polyester Polyol Resin EGOPA600 Consisting of Orthophthalic Acid and Ethylene Glycol In a polyester reaction vessel equipped with a stirrer, a nitrogen gas introduction pipe, a snider pipe, and a condenser, 396.34 parts of orthophthalic acid, 173.73 of ethylene glycol And 0.05 part of titanium tetraisopropoxide were charged, and the inner temperature was maintained at 220 ° C. by gradually heating so that the rectifying tube upper temperature did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol resin EGoPA600 having a number average molecular weight of 600 and a hydroxyl value of 119.4 mgKOH / g.

(Production Example 6) Polyester polyol composed of phthalic anhydride, succinic acid, and ethylene glycol Production method of EGoPASuA1800 Phthalic anhydride in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, water separator, etc. 103 parts, 30 parts of succinic acid, 75.3 parts of ethylene glycol, and 0.02 part of titanium tetraisopropoxide are gradually heated so that the upper temperature of the rectifying tube does not exceed 100 ° C. Held on. When the acid value became 2 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol EGoPASuA1800 having a number average molecular weight of 1800.

(Production Example 7) Method for producing polyester polyol EGtPA1500 comprising terephthalic acid and ethylene glycol
A polyester reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, a rectifying tube, a water separator, etc. was charged with 166.12 parts of terephthalic acid, 77.4 parts of ethylene glycol and 0.03 part of titanium tetraisopropoxide. The inner temperature was maintained at 260 ° C. by gradually heating so that the upper temperature of the distillation tube did not exceed 100 ° C. After maintaining at 260 degrees for 1 hour, the temperature is lowered to 250 degrees and heating is continued. When the acid value became 10 mgKOH / g or less, heating was continued at 100 torr under reduced pressure to finish the esterification reaction with an acid value of 2 mgKOH / g to obtain a polyester polyol EGtPA1500 having a number average molecular weight of 1500.

(Production Example 8)
Method for producing polyester polyol EGSuA1800 comprising succinic acid and ethylene glycol In a polyester reaction vessel equipped with a stirrer, nitrogen gas inlet tube, rectifying tube, moisture separator, etc., 100.7 parts of succinic anhydride, 73.9 ethylene glycol And 0.007 part of titanium tetraisopropoxide were charged, and the inner temperature was kept at 220 ° C. by gradually heating so that the temperature of the upper part of the rectifying tube did not exceed 100 ° C. When the acid value became 1 mgKOH / g or less, the esterification reaction was terminated to obtain a polyester polyol EGSuA1800 having a number average molecular weight of 1800.

In addition to Resin (A) in Production Example, Dick Dry LX-703VL (manufactured by DIC Graphics, Inc .: polyester polyol, ethyl acetate, non-volatile content / about 62%) is used as a solvent-based laminating adhesive main agent. The tests that were performed were also carried out. In the table, it is indicated as LX-703VL. The adhesive is a polyester polyol that does not contain an ortho-oriented dicarboxylic acid skeleton.

  The polyester polyol (A) obtained in the above synthesis example was first dissolved in ethyl acetate as a solvent by stirring with a stirrer at room temperature at the quantitative ratios in Tables 1 and 2 described later. For those that could be dissolved uniformly, a curing agent was added according to the formulation in Tables 1 and 2. However, the polyester polyols produced in Production Examples 7 and 8 were poorly soluble in ethyl acetate and could not be completely dissolved. Therefore, it was impossible to add a curing agent and evaluate as an adhesive. These polyester polyols were treated as comparative examples.

(Example 1)
The polyester polyol synthesized in Production Example 1 was dissolved with ethyl acetate according to the formulation shown in Table 1, and then an adhesive with an MDI-based curing agent added thereto was obtained. This adhesive was applied to the transparent vapor-deposited surface of a 12 μm-thick transparent vapor-deposited PET film using a bar coater # 8, and the diluting solvent was volatilized and dried with a dryer set at a temperature of 70 ° C. A polyethylene film is dry-laminated at a temperature of 40 ° C., a pressure of 0.4 MPa, and a laminating speed of 40 m / min, and this composite film is cured (aged) over 40 ° C./3 days, transparently deposited PET / adhesive / unstretched A multilayer film of polyethylene was obtained. Table 1 shows the layer configuration and the evaluation results of the adhesive described later. In this table, the content of ortho-oriented aromatic dicarboxylic acid or its anhydride in the raw material monomer with respect to all the components of polyvalent carboxylic acid (ortho-oriented aromatic ring content (mass%), and cured adhesive ( The MDI content (mass%) in the solid content was shown.

(Examples 2 to 6)
Example 1 A multilayer film in which the polyester polyol obtained in Production Examples 2 to 6 was used as an adhesive formulation containing an MDI-based curing agent in an adhesive cured product, and the various layer configurations described in Table 2 were changed to Example 1 Was obtained in a similar manner. The evaluation results for these multilayer films are also shown in Table 1.

(Comparative Examples 1-6)
In Comparative Examples 1 to 6, the polyester polyol obtained in Production Examples 1 to 6 was used as an adhesive formulation that does not contain an MDI-based curing agent in the adhesive cured product. A multilayer film having a changed layer structure was obtained in the same manner as in Example 1. The evaluation results for these multilayer films are also shown in Tables 2 and 3.

(Comparative Examples 7 and 8)
In Comparative Examples 7 and 8, an attempt was made to use the polyester polyol produced in Production Examples 7 and 8 as a resin (A) that does not contain an orthophthalic acid component in the polyester polyol. The solvent solubility was poor and could not be used for evaluation as an adhesive. “-” In the table indicates that evaluation could not be performed.

(Comparative Examples 9 and 10)
In Comparative Examples 9 and 10, using a general-purpose adhesive that does not contain an orthophthalic acid component in the polyester polyol, a multilayer film changed to the composition shown in Table 3 and various layer configurations was obtained in the same manner as in Example 1. . The evaluation results for these multilayer films are also shown in Tables 2 and 3.

(Use film)
The films used in the above Examples and Comparative Examples are as follows. None of the deposited films is overcoated.
<Stretched vapor deposition film>
Transparent PET: Barrier Rocks 1011HG (manufactured by Toray Film Processing Co., Ltd.)
・ Aluminum-deposited PET: 1510 (manufactured by Toray Film Processing Co., Ltd.)
Unstretched deposited film / aluminum deposited CPP: 2203 # 25 (manufactured by Toray Film Processing Co., Ltd.). Metal aluminum deposition is applied on the unstretched polypropylene film. In Tables 1 and 2, indicated as VMCPP.

<Unstretched film>
PET film: “E-5100” manufactured by Toyobo Co., Ltd., thickness 12 μm
Unstretched undeposited film / unstretched polyethylene film: Mitsui Chemicals Tosero Co., Ltd. TUX-HC thickness 60 μm. Notated as LLDPE in the table.

(Use hardener)
The curing agents used in the above examples and comparative examples are as follows.
(MDI curing agent)
MR-400: Nippon Polyurethane Co., Ltd. “Millionate MR-400” polymeric 4,4′-diphenylmethane diisocyanate, non-volatile component 100%, NCO% 30%.
MR-100: manufactured by Nippon Polyurethane Co., Ltd., “Millionate MR-100” polymeric 4,4′-diphenylmethane diisocyanate, nonvolatile component 100%, NCO% 30%. There are many low molecular weight components and low viscosity than MR-400.
(Non-MDI curing agent)
HA-300: “HA-300” manufactured by BASF Corporation, hexamethylene diisocyanate (HDI) allophanate, non-volatile component 100%, NCO% 17.5%
L-75: “Desmodur L-75” manufactured by Sumika Bayer Urethane Co., Ltd. (Adduct body of trimethylolpropane and 2,6-tolylene diisocyanate (TDI) (nonvolatile content is 75.0%, NCO% is 13) .4%)
D-110N: “Takenate D-110N” manufactured by Mitsui Chemicals, Inc., trimethylolpropane adduct of metaxylylene diisocyanate (XDI), non-volatile component 75.0%, NCO% 11.5%, solvent ethyl acetate KR-90: manufactured by DIC Graphics, “KR90s” polyisocyanate type curing agent, non-volatile component 90%, NCO% 30%, solvent ethyl acetate. Hexamethylene diisocyanate (HDI) containing curing agent.

(Evaluation method)
(1) Oxygen permeability The film obtained in various Examples and Comparative Examples, and an untreated vapor-deposited film as a reference example were JIS-K7126 (etc.) using a Mocon oxygen permeability measuring apparatus OX-TRAN2 / 21MH. According to the pressure method), the measurement was performed in an atmosphere of a temperature of 23 ° C., a humidity of 0%, and 90%. In the table, humidity is indicated as RH.

(2) Water vapor permeability The film obtained in various Examples and Comparative Examples, and an untreated vapor-deposited film as a reference example, were measured using a conductivity method “ISO-15106-" using a water vapor permeability measuring device 7002 manufactured by Illinois. 3 ”and measured in an atmosphere of 40 ° C. and 90% RH.

(Measurement method of laminate strength)
The multilayer film after aging is cut to a width of 15 mm in parallel with the coating direction, and between the stretched film and the unstretched film, the ambient temperature is 25 ° C. using a Tensilon universal testing machine manufactured by Orientec Co., Ltd. The peeling speed was set to 300 mm / min, and the tensile strength when peeled by the 180 degree peeling method was defined as the laminate strength.

As described above, the polyester containing ortho-oriented aromatic rings shown in Examples 1 to 6 in Table 1 and the adhesive containing MDI as a curing agent have high laminate strength and seal strength, and low oxygen and water vapor permeability. That is, it was found to exhibit a high barrier function.
For example, when Examples 1 and 2 and Comparative Examples 1, 2 and 9 in which transparent vapor-deposited PET and unstretched polyethylene are laminated are compared, when the HDI curing agents of Comparative Examples 1 and 9 are used, the laminate strength Although the seal strength was relatively good, the gas permeability was high. When the TDI curing agent of Comparative Example 2 was used, the gas permeability was low, but the laminate strength and seal strength were low.

Similarly, Examples 3 to 6 in which PET and an aluminum-deposited unstretched polypropylene (VMPP) film were laminated showed high barrier function and high laminate strength and seal strength as a VMCP-laminated film. On the other hand, Comparative Examples 3 and 6 using an HDI-based curing agent have relatively good laminate strength and seal strength as in the case of the transparent vapor-deposited film, but the gas permeability is high. In the case of TDI-based curing agent) and 5 (XDI-based curing agent), the laminate strength was hardly obtained.
Further, the polyester polyols having no orthophthalic acid skeleton of Comparative Examples 7 and 8 were poor in solvent solubility and could not be used as an adhesive.

  The adhesive and multilayer film (laminate) of the present invention are used for various packaging materials, and in particular, for barrier barrier flexible packaging having an inorganic compound layer, for example, for higher barriers, such as solar cell protective films and vacuum insulation packaging. It can be suitably used for gas barrier substrates for display elements, packaging materials for various batteries, and the like.

Claims (8)

In the laminating adhesive containing the polyester or polyester polyurethane resin (A) and the polyisocyanate (B),
The polyester or polyester polyurethane resin (A) has two or more hydroxyl groups in one molecule as a functional group, and an ortho-oriented aromatic dicarboxylic acid or an anhydride thereof as a polyvalent carboxylic acid as a monomer component constituting the polyester Is a polyester or polyester polyurethane resin (A) obtained using
An adhesive for laminating, wherein the polyisocyanate (B) is diisocyanate diisocyanate, polymeric diphenylmethane diisocyanate, and polyisocyanate (B) containing derivatives thereof.   The adhesive for laminating according to claim 1, wherein the content of diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, and derivatives thereof is 10% by mass or more in the laminating adhesive solid content. The resin (A) is a group consisting of a polyvalent carboxylic acid component containing at least one ortho-oriented aromatic dicarboxylic acid or anhydride thereof, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. The laminate adhesive according to claim 1 or 2, which is a polyester polyol obtained by polycondensation of a polyhydric alcohol component containing at least one selected. Ortho-oriented aromatic dicarboxylic acid or its anhydride is orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid The laminate adhesive according to any one of claims 1 to 3, which is at least one selected from the group consisting of or an anhydride thereof and 2,3-anthracene dicarboxylic acid or an anhydride thereof. Furthermore, the laminating adhesive in any one of Claims 1-4 containing a plate-shaped inorganic compound. A laminate obtained by using the laminate adhesive according to any one of claims 1 to 5. A layer selected from an inorganic layer, a metal foil layer, a metal vapor-deposited film layer, and a transparent vapor-deposited film layer and another layer are bonded via an adhesive layer obtained by the laminate adhesive according to any one of claims 1 to 5. The layered product according to claim 6 which has the composition constituted. A packaging material using the laminate according to claim 6 or 7.