JP5648856B2 - One-part curable gas barrier adhesive and film, container, and tube using the same - Google Patents

Description

  The present invention relates to a one-part curable gas barrier adhesive and a film, container, and tube using the same.

  Packaging materials such as food and beverages not only have functions such as strength, resistance to cracking, retort resistance, and heat resistance to protect the contents from various distribution, storage such as refrigeration and heat sterilization, etc. Various functions are required, such as excellent transparency so that the contents can be confirmed. On the other hand, when the bag is sealed by heat sealing, an unstretched polyolefin film having excellent heat processability is essential, but the unstretched polyolefin film has many functions that are insufficient as a packaging material.

When imparting a barrier function to a multilayer film, unstretched polyolefin films used for the inner layer (sealant side) have poor gas barrier properties and are difficult to impart a barrier function by coating or vapor deposition. Therefore, a barrier function is often imparted to various films (polyester resins such as polyethylene terephthalate (hereinafter abbreviated as PET), polyamide resins, stretched polyolefin resins) used on the outer layer side.

When coating these outer-layer films with gas, especially oxygen barrier function and inert gas barrier function, vinylidene chloride with high gas barrier properties has been widely used as a barrier coating material, but dioxin is generated when firing waste. There is a problem such as. Further, when a polyvinyl alcohol resin or an ethylene-polyvinyl alcohol copolymer is used as a barrier coating material, the gas barrier property is high under low humidity, but there is a problem that the gas barrier property is remarkably lowered under high humidity or after boiling treatment. In addition, a film provided with a vapor deposition layer of a metal oxide such as silica or alumina as a gas barrier layer is expensive and has a problem that the flexibility is poor and the barrier performance varies due to cracks and pinholes.

  On the other hand, a method of imparting a gas barrier function to an adhesive used at the time of lamination is also known. This method has an advantage that a multilayer film for an inert gas barrier can be produced without using a film having a special inert gas barrier function, due to the steps and configuration essential for producing a laminated film. As a container using such a gas barrier adhesive or a barrier laminate film using these, for example, in Patent Document 1 and Patent Document 2, a thermoplastic film layer that is an outer layer and a thermoplastic film that is a sealant layer A gas barrier laminate film is described in which a layer is bonded with a two-part curable epoxy resin composition composed of an epoxy resin and an amine epoxy resin curing agent.

The two-component curable adhesive has a problem that the degree of difficulty in controlling the coating thickness and the like is high because the viscosity changes due to the change in the curing condition after the addition of the curing agent. In particular, the epoxy-amine curing system has a high reaction rate, so that the viscosity change after mixing the two liquids is remarkably difficult to use from the viewpoint of the thickness stability of the coating laminate and the short pot life. In particular, in the case of an adhesive having a barrier function, coating with a uniform thickness is required.

  On the other hand, as an adhesive that has the disadvantages of two-component curing type, such as no need for two-component mixing operation and viscosity stability at the time of coating lamination, it is a precedent for one-component curing (moisture curing type) adhesives. There is technology. For example, Patent Document 3 discloses a one-part curable adhesive that is excellent in application workability such as initial adhesive strength and pasting time, and Patent Document 4 has a low hardness of the cured product due to temperature changes. A one-component urethane-based moisture curable composition having a small variation in hardness and excellent mechanical properties of the cured product is described. However, none of the prior art of one-part or moisture-curing adhesives has a gas barrier as a problem.

Japanese Patent No. 4092549 Japanese Patent No. 4366563 JP 2008-94905 A JP 2009-132832 A

  The problem to be solved by the present invention is a one-component curable gas barrier adhesive that has both a gas barrier function and an adhesive function, in addition to the complexity of mixing two liquids and the fear of concentration changes with mixing elapsed time, and the same It is providing the film, container, and tube using this.

  The present inventors have solved the above problems with a one-part curable gas barrier adhesive containing a polyisocyanate (A) having two or more isocyanate groups. More specifically, the polyisocyanate (A) has an aromatic ring or an aliphatic ring, and more specifically, the polyisocyanate (A) is a polyvalent compound containing at least one ortho-oriented aromatic dicarboxylic acid or anhydride thereof. Polyester polyol (B) structure obtained by polycondensation of a carboxylic acid component and a polyhydric alcohol component containing at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol It had a particularly excellent function.

  According to the present invention, unlike the two-component curable type, there is no change in viscosity after mixing the main component and the curing agent, and there is a characteristic of a one-component curable adhesive having high stability of coating laminating operation and thickness control. A gas barrier adhesive having a function can be provided. In addition, the gas barrier adhesive of the present invention can provide a multilayer film, a tube, and a container having a gas barrier function without using a gas barrier film.

[Polyisocyanate (A)]
The one-component curable gas barrier adhesive of the present invention contains a polyisocyanate (A) having two or more isocyanate groups. When a part of the polyisocyanate reacts with moisture in the outside air to form carbamic acid, a urea bond is formed simultaneously with decarboxylation via a carbamic anhydride formed by the reaction between the carbamic acid and isocyanate.
At this time, it has a gas barrier function due to a highly polar urea bond. Examples of the polyisocyanate compound used in the present invention include diisocyanates and trivalent or higher polyisocyanates, and it is preferable from the viewpoint of gas barrier function that an aromatic ring or an aliphatic ring is contained in a part of the skeleton. For example, as the isocyanate having an aromatic ring, those having a structure of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, or naphthalene diisocyanate are preferable. Further, as the isocyanate having an aliphatic ring, those having a structure of hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, isophorone diisocyanate, norbornone diisocyanate are preferable.

[Polyester polyol (B) in polyisocyanate (A)]
Furthermore, the polyisocyanate (A) in the present invention includes a polycarboxylic acid component containing at least one ortho-oriented aromatic dicarboxylic acid or an anhydride thereof in a part of the structure, ethylene glycol, 1,3-propanediol, It is preferable to contain a polyester polyol (B) component obtained by polycondensation with a polyol component containing at least one selected from the group consisting of 1,4-butanediol, neopentyl glycol, and cyclohexanedimethanol.

[Polyvalent carboxylic acid component in polyester polyol (B)]
In the polyester polyol (B) used by this invention, it is necessary to contain the component which polycondensed the polycarboxylic acid component containing at least 1 sort (s) of ortho orientation aromatic dicarboxylic acid or its anhydride. 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, it is especially preferable in it being the polyester polyol whose usage rate with respect to all these polycarboxylic acid components is 70-100 mass%.

(Other polycarboxylic acid components)
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; Polybasic acids such as droxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid and ester-forming derivatives of these dihydroxycarboxylic acids can be used alone or in a mixture of two or more. 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 in polyester polyol (B)]
In the polyester polyol (B) used in the present invention, a polyol component containing at least one selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, and cyclohexanedimethanol; It is preferable to contain a polyester polyol (B) component obtained by polycondensation. Among them, it is most preferable to use ethylene glycol because it is presumed that the smaller the number of carbon atoms between oxygen atoms, the less the molecular chain will be excessively flexible and the less likely to permeate oxygen.

(Other polyol components)
In the present invention, the above-mentioned polyhydric alcohol component is essential, but other polyhydric alcohol components may be copolymerized as long as the effects of the present invention are not impaired. Specifically, as the aliphatic 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 trivalent alcohols such as trimethylolpropane, trimethylolethane, tris (2-hydroxyethyl) isocyanurate, 1,2,4-butanetriol. , Pentaerythritol, dipentaerythritol and the like.

  Examples of the catalyst used in the reaction for obtaining the polyester polyol (B) include tin-based catalysts such as monobutyltin oxide and dibutyltin oxide, titanium-based catalysts such as tetra-isopropyl-titanate and tetra-butyl-titanate, and tetra-butyl-zirconate. Acid catalysts such as zirconia-based catalysts. 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 to 1000 ppm, more preferably 10 to 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.

  These polyester polyols (B) have a number average molecular weight of 300 to 3000, which is particularly preferable because a one-component curable adhesive having an excellent gas barrier function can be obtained. More preferably, the number average molecular weight is 400-2500.

  The polyester polyol (B) 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., there is a possibility that sufficient gas barrier properties may not be obtained due to intense molecular motion of the polyester polyol near normal temperature.

(Polyester polyol (B) as a one-component adhesive)
The one-part adhesive of the present invention needs to have at least two isocyanate groups. Accordingly, when the polyester polyol (B) is contained, at least two of the polymer terminals must be isocyanate-terminated. For this reason, the polyester polyol (B) is reacted with at least two isocyanate compounds to form an isocyanate-terminated polyester polyurethane. At this time, the polyester polyol (B) is introduced with an appropriate urethane group concentration in the polymer chain by the urethane elongation reaction, and is given a further gas barrier function due to the interaction between the molecular chains by this polar group. The molecular weight of the polyester polyurethane at this time is not particularly limited, but a number average molecular weight of 1000 to 20000, particularly preferably 2000 to 15000 is preferable from the viewpoints of a gas barrier function and an adhesive function.

  The polyester polyurethane is preferably an isocyanate having an aromatic ring or an aliphatic ring, and the isocyanate having an aromatic ring includes the structures of toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and naphthalene diisocyanate. Those having the following are preferred. Further, as the isocyanate having an aliphatic ring, those having a structure of hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, isophorone diisocyanate, norbornone diisocyanate are preferable.

  Moreover, when performing this polyester polyurethane reaction, a gas barrier characteristic can also be improved by making compounds other than polyester polyol (B) react simultaneously with isocyanate. At that time, in addition to the hydroxyl group, if at least two primary to tertiary amines are contained, the gas barrier improving material can be used. Examples of these include short-chain polyhydric alcohols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, and the polyester polyol (B) skeleton of cyclohexanedimethanol. In addition to the above materials, examples of polyvalent amines include primary amines such as ethylenediamine, 1,3-propanediamine, 1,2-propanediamine, and 1,4-butanediamine. In addition, other secondary amine-containing nitrogen-containing structures capable of imparting high polarity include 3-bis (hydroxymethyl) -4,5-dihydroxyimidazolidin-2-one, piperazine, bishydroxyethylaniline, 1,2- Examples include bis [di (hydroxyethyl) amino] ethane and hydroxyethylpiperazine. Furthermore, examples of alcohol aminos include 1-methylamino-2,3-propanediol, 1-aminopropanediol, and the like.

(Plate-like inorganic compound)
In the one-component curable adhesive resin composition of the present invention, a plate-like inorganic compound may be contained.
In the case where a plate-like inorganic compound is used in the present invention, it has an effect of improving the adhesive ability by the cement effect and improving the gas barrier property by the maze effect.

  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 directly affect the barrier property directly, but the dispersibility to the resin composition is significantly inferior to the swellable inorganic compound with respect to water, and the resin composition increases as the addition amount is increased. Coatability becomes a problem because it becomes sticky 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. An inorganic layered compound is used individually or in combination of 2 or more types.

The plate-like inorganic compound used in the present invention is preferably nonionic or non-swelling even if it has a charge.

  Examples of such a plate-like inorganic compound used in the present invention include intercalated kaolinite-serpentine clay minerals (such as halloysite, kaolinite, endellite, dickite, nacrite, antigolite, chrysotile). The light-talc family (pyrophyllite, talc, kerolai, etc.) can be mentioned.

  In addition, the plate-like inorganic compound used in the present invention is preferably non-swellable with respect to water even if it has a charge.

  Examples of the plate-like inorganic compound used in the present invention include kaolinite-serpentine clay minerals (such as halloysite, kaolinite, enderite, dickite, nacrite, antigolite and chrysotile), and pyrophyllite. -Talc (pyrophyllite, talc, kerolai, etc.), mica or mica clay mineral (mica, muscovite, phlogopite, etc.), margarite, tetrasilic mica, teniolite, etc. (Clinochlor, chamosite, nimite, etc.), hydrotalcite, plate-like barium sulfate and the like.

  The average particle diameter in the present invention means a particle diameter having the highest appearance frequency when the particle size distribution of a certain plate-like inorganic compound is measured with a light scattering measurement device. The average particle diameter of the plate-like inorganic compound used in the present invention is not particularly limited, but is preferably 0.1 μm or more, and more preferably 1 μm or more. If the average particle size is 0.1 μm or less, the length of the long side is short, which causes a problem that it is difficult to improve the gas barrier function without lengthening the detour path of oxygen molecules. The side with a large average particle diameter is not particularly limited. When a large plate-like inorganic compound is contained by the laminating method, when defects such as streaks occur on the coated surface, it is preferable to use a material having an average particle size of 100 μm or less, more preferably 20 μm or less.

The aspect ratio of the plate-like inorganic compound used in the present invention is preferably higher in order to improve the barrier ability due to the labyrinth effect of various gas molecules. Specifically, it is preferably 3 or more, more preferably 10 or more, and most preferably 40 or more. Moreover, although the content rate of a plate-shaped inorganic compound is arbitrary, it is preferable that it is 50 mass parts or less. This is because if it exceeds 50 parts by mass, the coating operation may become difficult, or the adhesion of the coating film may be insufficient.
The content of the inorganic compound (PWC of the blend) can be obtained from the following formula (a).

  As a method of dispersing the inorganic compound used in the present invention in the gas barrier one-part curable adhesive resin composition, a known dispersion method can be used. 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. Moreover, as a time to disperse | distribute, there exist the method of disperse | distributing beforehand in an adhesive agent, and the method of disperse | distributing just before coating lamination, and any method may be sufficient as it. However, in the case of a method of dispersing in advance in the adhesive, it is preferable from the viewpoint of storage stability that the inorganic compound is sufficiently dried and kept in a state not containing water.

(One-component curable adhesive and other components)
The one-component curable adhesive of the present invention may contain various additives as long as the gas barrier property is not impaired. Examples of additives include inorganic fillers such as silica, alumina, aluminum flakes, and glass flakes, stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, etc.), plasticizers, antistatic agents, lubricants, and antiblocking agents. Examples include agents, colorants, fillers, crystal nucleating agents and the like.

  Moreover, you may add the compound etc. which have an oxygen trap function further as needed. Examples of the compound having an oxygen scavenging function include low molecular organic compounds that react with oxygen such as hindered phenols, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, pyrogallol, cobalt, manganese, nickel, iron, Examples include transition metal compounds such as copper.

  The adhesive of the present invention can be used by being applied to a substrate film or the like. The coating method is not particularly limited and may be performed by a known method. For example, in the case of a solvent type whose viscosity can be adjusted, it is often applied by a gravure roll coating method or the like. Moreover, when it is a solventless type and has a high viscosity at room temperature and is not suitable for gravure roll coating, it can be coated with a roll coater while heating. When using a roll coater, it is preferable to apply in a state of heating from room temperature to about 120 ° C. so that the viscosity of the adhesive of the present invention is about 500 to 2500 mPa · s.

  The adhesive of the present invention can be used as an adhesive for various applications that require gas barrier properties against polymers, paper, metals, etc. as a gas barrier adhesive.

Hereinafter, an adhesive for film lamination will be described as one of specific applications.
The adhesive of the present invention can be used as an adhesive for film lamination. Since the laminated film is excellent in gas barrier properties, it can be used as a laminated film for gas barrier.

  The film for lamination used in the present invention is not particularly limited, and a thermoplastic resin film can be appropriately selected according to a desired application. For food packaging, for example, polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low density polyethylene film, HDPE: high density polyethylene film) and polypropylene film (CPP: unstretched polypropylene) Polyolefin film such as film, 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.

  The adhesive of the present invention can be preferably used as an adhesive for a laminated film formed by bonding a plurality of the same or different resin films. The resin film may be appropriately selected depending on the purpose. For example, when used as a packaging material, the outermost layer is a thermoplastic resin film selected from PET, OPP, and polyamide, and the innermost layer is unstretched polypropylene. (Hereinafter abbreviated as CPP), a composite film consisting of two layers using a thermoplastic resin film selected from a low density polyethylene film (hereinafter abbreviated as LLDPE), or an outermost layer selected from, for example, PET, polyamide and OPP A three-layer composite using a thermoplastic resin film, a thermoplastic resin film that forms an intermediate layer selected from OPP, PET, and polyamide, and a thermoplastic resin film that forms an innermost layer selected from CPP and LLDPE Heat to form an outermost layer selected from a film, for example, OPP, PET, polyamide Selected from a plastic film, a thermoplastic film forming a first intermediate layer selected from PET and nylon, and a thermoplastic film forming a second intermediate layer selected from PET and polyamide, LLDPE, and CPP A composite film composed of four layers using a thermoplastic resin film forming the innermost layer can be preferably used as a food packaging material as a gas barrier film.

  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.

After the adhesive of the present invention is applied to one of the thermoplastic resin films, the other thermoplastic resin film is stacked and bonded together by lamination to obtain the laminated film for gas barrier of the present invention. As the lamination method, known lamination such as dry lamination and extrusion lamination can be used.
Specifically, in the dry lamination method, the adhesive of the present invention is applied to one of the base films by the gravure roll method, and the other base film is stacked and bonded by dry lamination (dry lamination method). The temperature of the laminate roll is preferably about room temperature to 60 ° C.

  In the case of the extrusion laminating method, the organic solvent solution of the adhesive of the present invention is applied to the base film as a bonding aid (anchor coating agent) with a roll such as a gravure roll, and the solvent is dried and cured at room temperature to 140 ° C. After the reaction, a laminate film can be obtained by laminating the polymer material melted by the extruder. The polymer material to be melted is preferably a polyolefin resin such as a low density polyethylene resin, a linear low density polyethylene resin, or an ethylene-vinyl acetate copolymer resin.

  Moreover, it is preferable that the laminated | multilayer film for gas barriers of this invention perform aging after preparation. If polyisocyanate is used as a curing agent, the aging condition is from room temperature to 80 ° C., for 12 to 240 hours, during which adhesive strength is generated.

Since the adhesive of the present invention is characterized by having a high gas barrier property, the laminate film formed by the adhesive is a PVDC coat layer, a polyvinyl alcohol (PVA) coat layer, an ethylene-vinyl alcohol copolymer ( EVOH) Film layer, metaxylylene adipamide film layer, inorganic vapor deposited film layer deposited with alumina, silica, etc. .
In the present invention, in order to provide an even higher barrier function, a film in which a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina is laminated, polyvinyl alcohol, or ethylene / vinyl alcohol as necessary. A barrier film containing a gas barrier layer such as a polymer or vinylidene chloride can be used in combination to provide a higher barrier function.

(Gas component types that can block permeation)
Gas that can be shut off by the multilayer film for gas barrier of the present invention includes oxygen, inert gas such as carbon dioxide, nitrogen and argon, alcohol components such as methanol, ethanol and propanol, phenols such as phenol and cresol, Aroma components comprising low molecular weight compounds such as soy sauce, sauce, miso, lemonene, menthol, methyl salicylate, coffee, cocoa shampoo, rinse, etc. can be exemplified.

(Use as gas barrier container of the present invention)
Further, the gas barrier adhesive of the present invention can be used as an adhesive layer of a gas barrier container. The said container can be used as containers, such as sauces, such as coffee, cocoa, miso, yoghurt, cooked cooked rice, sauces for grilled meat, dressings, cheese containers, and pizza.

(Use as laminated tube of the present invention)
Furthermore, the gas barrier adhesive of the present invention can be used as an adhesive layer for laminated tubes. The tube can be used as a tube for kneaded mustard, kneaded wasabi, condensed milk, fresh cream, bean plate soy, ketchup, mayonnaise, mustard, butter, toothpaste, hair dye, hand cream, detergent, hair cream.

  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 Amorphous Polyester Polyol EGOPA600 Containing Phthalic Anhydride and Ethylene Glycol Phthalic Anhydride 148 in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, moisture separator, and the like 0.1 part, 84.2 parts of ethylene glycol and 0.03 part of titanium tetraisopropoxide were charged, and the inner temperature was maintained at 205 ° 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 600.

(Production Example 2) Amorphous polyester polyol composed of phthalic anhydride and neopentyl glycol NPGoPA600 production method Phthalic anhydride in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, water separator, etc. 148.1 parts, neopentylglycol 153.4 parts and titanium tetraisopropoxide 0.03 parts are charged, and the inner temperature is maintained at 205 ° C by gradually heating so that the upper temperature of the rectifying tube does not exceed 100 ° C. did. 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 600.

(Production Example 3) Amorphous polyester polyol composed of phthalic anhydride, succinic acid, and ethylene glycol EGOPASuA600 production method A polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, water separator, etc. Charge 64.7 parts of phthalic anhydride, 27.7 parts of succinic acid, 57.5 parts of ethylene glycol and 0.01 part of titanium tetraisopropoxide, and gradually heat so that the upper temperature of the rectification tube does not exceed 100 ° C. The internal temperature was maintained at 205 ° 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 600.

(Production Example 4) Production Method of Amorphous Polyester Polyol EGoNA600 Composed of Naphthalene 2,3-dicarboxylic Anhydride and Ethylene Glycol Polyester Reaction Vessel Comprising Stirrer, Nitrogen Gas Introducing Tube, Rectification Tube, Moisture Separator, etc. Are charged with 198.0 parts of naphthalene 2,3-dicarboxylic acid anhydride, 84.2 parts of ethylene glycol and 0.03 part of titanium tetraisopropoxide, and gradually added so that the upper temperature of the rectification tube does not exceed 100 ° C. The inner temperature was maintained at 205 ° C. by heating. 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 600.

(Production Example 5)
Method for producing polyester polyol CHDMMoPA600 comprising phthalic anhydride and 1,4-cyclohexanedimethanol 148.1 parts of phthalic anhydride in a polyester reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, a rectification tube, a water separator, etc. First, 231.0 parts of 1,4-cyclohexanedimethanol and 0.03 part of titanium tetraisopropoxide were charged, and the inner temperature was maintained at 205 ° C. by gradually heating so that the upper temperature of the rectification tube did not exceed 100 ° C. did. 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 600.

(Production example for comparative example)
(Production Example 6) Method for Producing Polyester Polyol HGoPA600 Consisting of Phthalic Anhydride and 1,6-Hexanediol Phthalic anhydride in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, moisture separator, etc. 148.1 parts, 1,6-hexanediol 179.1 parts and titanium tetraisopropoxide 0.03 parts were charged, and the inner temperature was increased by gradually heating so that the upper temperature of the rectification tube did not exceed 100 ° C. Held at 0C. 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 600.

(Production Example 7) Production method of polyester polyol EGtPA600 composed of terephthalic acid and ethylene glycol In a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, moisture separator, etc., 166.1 parts of terephthalic acid, ethylene Glycol (84.2 parts) and titanium tetraisopropoxide (0.03 part) were charged, and the inner temperature was maintained at 205 ° 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 600.

(Production Example 8) Production Method of Polyester Polyol EGnPGiPASbA800 Consisting of Isophthalic Acid, Sebacic Acid and Ethylene Glycol, Neopentyl Glycol Ethylene in a polyester reaction vessel equipped with a stirrer, nitrogen gas introduction tube, rectification tube, moisture separator, etc. 16.3 parts of glycol, 27.3 parts of neopentyl glycol, 50.5 parts of isophthalic acid, 20.5 parts of sebacic acid, and 0.03 part of titanium tetraisopropoxide, and the upper temperature of the rectifying tube is 100 ° C. The internal temperature was maintained at 205 ° C. by gradually heating so as not to exceed. 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 800.

  The raw material monomer composition of the polyester polyol for Examples obtained in Production Examples 1 to 5, the number average molecular weight of the resin, the content of the ortho-oriented aromatic dicarboxylic acid or its anhydride in the raw material monomer with respect to all the components of the polyvalent carboxylic acid Table 1 shows (ortho-oriented aromatic ring content (% by mass)).

  The raw material monomer composition of the polyester polyol for Comparative Examples obtained in Production Examples 6 to 8, the number average molecular weight of the resin, the content of the ortho-oriented aromatic dicarboxylic acid or its anhydride in the raw material monomer with respect to all the components of the polyvalent carboxylic acid Table 2 shows (ortho-oriented aromatic ring content (% by mass)).

Examples 1 to 7 Method for synthesizing urethane-terminated polyester polyurethane or polyester polyurea polyurethane (Example 1)
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, and a dropping funnel, 48.0 g of the polyester polyol EGoPA600 synthesized in Production Example 1 was dissolved in 70.6 g of methyl ethyl ketone. Then, it heated at 60 degreeC with the oil bath. Next, 22.6 g of metaxylylene diisocyanate (XDI) was charged into the dropping funnel and added dropwise over 1 hour. In this case, air cooling control was performed so as not to increase to 65 ° C. or higher when a temperature increasing tendency was observed. After completion of the dropping, the mixture was stirred at about 60 ° C. for 1 hour to obtain a methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a terminal isocyanate group. The obtained methyl ethyl ketone solution was used as a one-component curable adhesive. The number average molecular weight at this time is about 1800.

(Example 2)
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, and a dropping funnel, 30.0 g of the polyester polyol NPGoPA600 synthesized in Production Example 2 was dissolved in 43.2 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a terminal isocyanate group was obtained in the same manner as in Example 1 except that 13.2 g of toluene diisocyanate (TDI) was used as the isocyanate. The obtained liquid was used as a one-component curable adhesive. The number average molecular weight at this time is about 1800.

Example 3
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, and a dropping funnel, 30.0 g of the polyester polyol EGoPASuA600 synthesized in Production Example 3 was dissolved in 41.9 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a terminal isocyanate group was obtained in the same manner as in Example 1 except that 11.9 g of hydrogenated metaxylylene diisocyanate (HXDI) was used as the isocyanate. It was. The obtained liquid was used as a one-component curable adhesive. The number average molecular weight at this time is about 3400.

Example 4
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, and a dropping funnel, 30.0 g of the polyester polyol EGONA600 synthesized in Production Example 4 was dissolved in 41.3 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a terminal isocyanate group was obtained in the same manner as in Example 1 except that 11.3 g of metaxylylene diisocyanate (XDI) was used as the isocyanate. The obtained liquid was used as a one-component curable adhesive. The number average molecular weight at this time is about 4200.

(Example 5)
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, and a dropping funnel, 30.0 g of the polyester polyol CHDMMoPA600 synthesized in Production Example 5 was dissolved in 43.3 g of methyl ethyl ketone. A methyl ethyl ketone solution of a polyester polyurethane having a resin content of 50% and having a terminal isocyanate group was obtained in the same manner as in Example 1 except that 13.3 g of toluene diisocyanate (TDI) was used as the isocyanate. The number average molecular weight at this time is about 1700. In this solution, 5.0 g of kaolin powder “HM6040” (manufactured by Heng Hao, muscovite / non-swelling, interlayer ionicity, plate-like, average particle size / 20 μm, aspect ratio / about 100) is dispersed and the inorganic content is A 10.3-mass% one-component curable adhesive was obtained.

(Example 6: One-component curable adhesive containing alcohol amine skeleton)
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, and a dropping funnel, 18.8 g of xylylene diisocyanate (XDI) as an isocyanate was dissolved in 18.8 g of methyl ethyl ketone. While maintaining this at 60 ° C., a resin solution prepared by dissolving 30.0 g of the polyester polyol EGOPA600 synthesized in Production Example 1 in 31.8 g of methyl ethyl ketone was added dropwise and reacted while maintaining at 60 ° C. over 1 hour. It was. Further, 1.8 g of N-methylethyl alcohol (NMEA), which is an amino alcohol as a nitrogen-containing compound for improving the oxygen barrier, was slowly added over 30 minutes to cause a reaction. By the above reaction, a methyl ethyl ketone solution of polyester polyurea polyurethane having a resin content of 50% and having a terminal isocyanate group was obtained. The obtained liquid was used as a one-component curable adhesive. The number average molecular weight at this time is about 2000.

(Example 7: One-part curable adhesive containing piperazine skeleton)
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, and a dropping funnel, 17.7 g of xylylene diisocyanate (XDI) as an isocyanate was dissolved in 17.7 g of methyl ethyl ketone. While maintaining this at 60 ° C., a resin solution prepared by dissolving 30.0 g of the polyester polyol EGoPA600 synthesized in Production Example 1 in 32.3 g of methyl ethyl ketone was added dropwise while maintaining the temperature at 60 ° C. over 1 hour. I let you. Further, 2.15 g of piperazine anhydride (PIP), which is a nitrogen-containing compound, was further added as a nitrogen-containing compound for improving the oxygen barrier over 30 minutes to cause a reaction. As a result, a methyl ethyl ketone solution of polyester polyurea polyurethane having a resin content of 50% and having an isocyanate group at the end was obtained. The obtained liquid was used as a one-component curable adhesive. The number average molecular weight at this time is about 2000.

(Comparative Examples 1-3: Synthesis method of polyester polyurethane)
(Comparative Example 1)
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, and a dropping funnel, 48.0 g of the polyester polyol HGoPA600 synthesized in Production Example 7 was dissolved in 70.6 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a terminal isocyanate group was obtained in the same manner as in Example 1 except that 22.6 g of metaxylylene diisocyanate (XDI) was used as the isocyanate. The obtained liquid was used as a one-component curable adhesive. The number average molecular weight at this time is about 1800.

(Comparative Example 2)
An attempt was made to dissolve 40.0 g of the polyester polyol EGtPA600 synthesized in Production Example 8 in 70.2 g of methyl ethyl ketone in a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, and a dropping funnel. I did not. Attempting to melt in the refluxed state after raising the temperature, but still could not be dissolved, this polyester can not be synthesized as a terminal isocyanate type polyester polyurethane that can be made into a paint, can be obtained as a one-part curable adhesive could not.

(Comparative Example 3)
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, and a dropping funnel, 48.0 g of the polyester polyol EGnPGiPASbA800 synthesized in Production Example 7 was dissolved in 70.2 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having an isocyanate group at the end was obtained in the same manner as in Example 1 except that 22.2 g of toluene diisocyanate (TDI) was used as the isocyanate. The obtained liquid was used as a one-component curable adhesive.

(Production method of multilayer film)
(Coating and aging methods)
Wherein each of the embodiments, the 1-part curable solvent type adhesive of Comparative Example, by using a bar coater, PET film (thickness 12μm so that the coating amount 5.0 g / ^{m 2} (solid content), Toyobo ( The product was applied to a corona-treated surface of “E-5100” manufactured by Co., Ltd., and the diluted solvent was volatilized and dried using a dryer set at a temperature of 70 ° C. Laminate the adhesive surface of the PET film coated with the adhesive and the corona-treated surface of 60 μm thick unstretched polyethylene (LLPDE) film (“TUX-HC” manufactured by Tosero Co., Ltd.), and then apply the ONY film film / adhesion. A composite film having a layer configuration of layer / LLPDE film was prepared. Next, this composite film was aged at 40 ° C. for 3 days to cure the adhesive, and a gas barrier laminated film was obtained.

(Evaluation method)
(1) Oxygen transmission rate The films obtained in various examples and comparative examples were subjected to 23 ° C. and 90% RH in accordance with JIS-K7126 (isobaric method) using an oxygen transmission rate measuring device OX-TRAN2 / 21MH manufactured by Mocon. Measured under the atmosphere of Note that RH indicates humidity. The measured value of the PET film (thickness 12 μm, “E-5100” manufactured by Toyobo Co., Ltd.) used as the substrate was 100 cc / m ² · day · atm.

(2) Nitrogen gas permeability The films obtained in various Examples and Comparative Examples were cut into 10 cm × 10 cm squares. This was set in a GTR tester “M-C1” (manufactured by Toyo Seiki Co., Ltd.) which is a differential pressure method type gas permeability measuring device, and nitrogen gas permeability was measured as a representative of inert gas. The measurement temperature is 25 ° C. Further, the humidity condition corresponds to measurement at 0% according to the measurement principle of the differential pressure method. The measured value of the PET film (thickness 12 μm, “E-5100” manufactured by Toyobo Co., Ltd.) used as the substrate was 40 cc / m ² · day · atm.

(3) Incense properties The films obtained in various examples and comparative examples were cut into 10 cm × 15 cm squares. Fold the long side of the film in half, heat seal two sides of the 10cm x 7.5cm square at 160 ° C for 1 second, add 1cc of soy sauce, heat seal the other side, and seal in three directions Sealed with a mold. The bag was immediately placed in a mayonnaise bottle (M-70) manufactured by Koyo Glass Co., Ltd., sealed, and stored for 2 months or more at a temperature of 27 ° C. and a relative humidity of 60%. Each time, the presence or absence of odor leakage was confirmed by a sensory test. The case where the odor leaked within 3 days was evaluated as “X”, the case where the odor leaked within 7 days was indicated as “△”, the case where the odor leaked within 14 days was indicated as “◯”, and the case where no odor leaked over 2 months was indicated as “◎”.

  The results in each example are shown in Table 3, and the results in each comparative example are shown in Table 4. In the table, the type and amount of the polyester polyol, isocyanate, nitrogen-containing compound for improving the barrier, and layered inorganic component used are described. Various evaluation results were described.

  As described above, the polyester polyurethane one-component curable adhesive obtained by polymerizing the polyester polyol containing an ortho-oriented aromatic ring and the aromatic ring or the polyisocyanate containing an alicyclic structure shown in Examples 1 to 7 is good. An oxygen barrier under high humidity, an inert gas barrier typified by nitrogen gas, and aroma retention were shown. Moreover, all had sufficient laminate strength of 6N or more.

  On the other hand, in the polyester polyurethane using the polyester polyol different from the essential structure in the present invention shown in Comparative Examples 1 and 3, the gas barrier function was not developed although the laminate strength was good. In addition, the polyester polyol containing the para-oriented aromatic ring of Comparative Example 2 was poor in solvent solubility and could not produce a one-part curable adhesive.

Since the one-part adhesive of the present invention has a gas barrier property such as oxygen, as a one-part curable adhesive for film for the packaging material, in addition to various foods and beverage packaging materials, various fragrances and oxygen deterioration Sanitary fields including scents such as shampoos, rinses, detergents, softeners, soaps, pet foods, insect repellents, fragrances, hair dyes, perfumes, pesticides, etc. It can be suitably used for soft packaging materials in fields where it is desired to prevent the release of fragrances such as organic solvents and low molecular components. In addition, there is a feature that the two-component mixing which is an advantage of the one-component adhesive is not necessary, and the viscosity change immediately before the coating lamination is not required. Furthermore, it can also be used as a coating material that can impart gas barrier properties by means such as coating, spraying, dipping, and dripping to a material that is desired to impart gas barrier properties centered on oxygen other than soft packaging materials. For example, one-part curable adhesive for protective film for solar cells, one-part curable adhesive for gas barrier substrates for display elements, one-part curable adhesive for building materials, one-part curable adhesive for industrial materials, etc. Any application where oxygen barrier properties are desired can be suitably used.

Claims (7)

A one-part curable gas barrier adhesive comprising a polyisocyanate (A) having two or more isocyanate groups ,
A group in which the polyisocyanate (A) is composed of a polyvalent carboxylic acid component containing at least one of ortho-oriented aromatic dicarboxylic acid or anhydride thereof, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. A one-component curable gas barrier adhesive having a polyester polyol (B) structure obtained by polycondensation of a polyhydric alcohol component containing at least one selected from the group consisting of: 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 one-component curable gas barrier adhesive according to claim 1 , which is at least one polycarboxylic acid selected from the group consisting of 2,3-anthracene dicarboxylic acid or an anhydride thereof, or an anhydride thereof, or an anhydride thereof. . The one-component curable gas barrier adhesive according to claim 1, wherein the polyisocyanate (A) having an aromatic ring has a metaxylene diisocyanate or a toluene diisocyanate structure. The one-component curable gas barrier according to any one of claims 1 to 3, obtained by dissolving the polyisocyanate (A) in a ketone solvent, an ester solvent, or a mixed solvent containing a ketone solvent or an ester solvent. -Component curable gas barrier multilayer film having a layer obtained by using a functional adhesive. The multilayer film for gas barriers which has at least a base film layer or a sealant layer in addition to the layer obtained using the one-pack curable gas barrier adhesive according to any one of claims 1 to 3 . Gas barrier container used as an adhesive layer of an component curable barrier adhesive according to any one of claims 1-3. Gas barrier tube is used as an adhesive layer of an component curable barrier adhesive according to any one of claims 1-3.