JP5617831B2 - Gas barrier coating agent and film using the same - Google Patents

Description

  The present invention relates to a gas barrier coating agent and a film 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.

  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.

  In the case of providing a gas, particularly an oxygen barrier function, by coating these outer layer side films, vinylidene chloride having a high gas barrier property has been frequently used as a barrier coating material, but there are problems such as generation of dioxins during firing of waste. is there. 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.

  As a coating technique different from these, Patent Document 1 discloses a polyurethane resin having a total urethane group and urea group concentration of 25 to 60% by weight and having an acid group, a swellable inorganic layered compound, and a polyamine compound. An oxygen barrier aqueous resin composition is described. Patent Document 2 discloses a polyurethane resin having an isophthalic acid skeleton and a terephthalic acid skeleton as essential components and an aromatic hydrocarbon group concentration of 10% by weight and a continuous number of methylene chains of 4 or less, and a swellable inorganic layered compound. The gas barrier aqueous resin composition is described.

The reason why these techniques are aqueous resin compositions is presumed to be because they use a highly polar resin component to enhance the oxygen barrier function. Aqueous solvents are often good for the environment, but on the other hand, they have a higher boiling point than solvent-based coating materials and a lower evaporation rate, resulting in poor drying. Therefore, if the drying is insufficient, there is a problem that blocking occurs in which the films partially stick together at the time of winding. In order to prevent this, the coating line speed becomes slow and the temperature of the drying furnace needs to be increased.

Patent No. 4434908 Japanese Patent No. 4596528

  The problem to be solved by the present invention is to provide a non-chlorine gas barrier coating agent based on an organic solvent having good drying properties. Another object of the present invention is to provide a gas barrier film to which a gas barrier function is imparted by applying the present coating agent.

  The present inventors include 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, and an ortho-oriented aromatic The above problems have been solved by a gas barrier coating agent comprising a polyester polyol containing a component obtained by polycondensation of a polycarboxylic acid component containing at least one dicarboxylic acid or an anhydride thereof and a polyisocyanate having two or more isocyanate groups.

  According to the present invention, it is possible to provide a non-chlorine-based gas barrier coating agent that is excellent in solubility in a general-purpose solvent in ethyl acetate, methyl ethyl ketone and the like, has quick drying, has a simple coating process, and has excellent gas barrier properties.

  In the present invention, the polyester polyol (A) and the polyisocyanate (B) having two or more isocyanate groups are contained as components of the gas barrier coating agent.

[Polyester polyol (A)]
The polyester polyol (A) used in the present invention is a polyol component (a1) containing at least one selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, and cyclohexanedimethanol. And a polycarboxylic acid component (a2) containing at least one ortho-oriented aromatic dicarboxylic acid or anhydride thereof.

(Polyol component (a1))
The polyol component (a1) used in the gas barrier coating agent of the present invention is at least one selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, and cyclohexanedimethanol. Need to include. Among them, ethylene glycol is most preferably used because it is presumed that the smaller the number of carbon atoms between oxygen atoms, the less the molecular chain becomes excessively flexible and the less oxygen permeates.

(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.

(Polycarboxylic acid component (a2))
The polyester polyol (A) used in the present invention needs to contain a component obtained by polycondensation of a polycarboxylic acid component (a2) containing at least one ortho-oriented aromatic dicarboxylic acid or anhydride 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, 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.

  Examples of the catalyst used in the reaction for obtaining the polyester polyol (A) 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 (A) have a number average molecular weight of 400 to 5000, which is particularly preferable because a coating agent having an excellent balance of gas barrier function and solvent solubility can be obtained. More preferably, the number average molecular weight is 500-2500.

  The polyester polyol (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., 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.

(Polyisocyanate (B) having two or more isocyanate groups)
In the present invention, it is necessary to contain a polyisocyanate (B) having two or more isocyanate groups. This polyisocyanate reacts at least partly with the polyester polyol (A) to form a urethane structure, so that it becomes highly polar as a resin component and exhibits a gas barrier function by agglomerating between polymer chains. The polyisocyanate compound used in the present invention includes diisocyanate and trivalent or higher polyisocyanate, which may be either a low molecular compound or a high molecular compound. If an aromatic ring or an aliphatic ring is contained in a part of the skeleton, a gas barrier is used. It is preferable from the viewpoint of function. For example, the isocyanate having an aromatic ring is toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, and the isocyanate having an aliphatic ring is 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.

  Moreover, as long as it is an isocyanate compound containing an aromatic ring or an aliphatic ring, it may be a blocked isocyanate. As the isocyanate blocking agent, for example, if it contains aromatics, phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol, etc. Also included are active methylene compounds such as aromatic amines, imides, acetylacetone, acetoacetate ester, and malonic acid ethyl ester, mercaptans, imines, ureas, diaryl compounds, sodium bisulfite, and the like. The blocked isocyanate can be obtained by subjecting the above isocyanate compound and an isocyanate blocking agent to an addition reaction by a conventionally known appropriate method.

  In the gas barrier coating material of the present invention, the polyester polyol (A) and the polyisocyanate (B) may be used as a two-component mixed type as long as they satisfy various characteristics as a gas barrier coating material. ) And polyisocyanate (B) may be used after synthesizing a polyester polyurethane.

(Polyester polyurethane type coating material)
In the present invention, a polyester polyurethane type coating material is preferably used from the viewpoint of coating suitability and low adhesiveness that hinders film winding. This type of coating agent is a material obtained by extending a polyester polyol (A) with a polyisocyanate (B). These materials have an appropriate urethane group concentration in the polymer chain, so that the gas barrier function due to the interaction between molecular chains with a certain polarity, solubility in organic solvents, and good coating due to the high molecular weight. This is particularly preferable since various characteristics of workability are balanced. The terminal functional group of the material may be either a hydroxyl group or an isocyanate group, but it is preferably a hydroxyl group terminal from the viewpoint that stickiness is less likely to occur when the molecular weight is low. The molecular weight of the polyester polyurethane in the present invention 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 coating suitability, drying properties, and organic solvent solubility.

(Two-component mixed coating material)
In the present invention, in addition to the polyester polyurethane type coating material, the polyester polyol (A) and the polyisocyanate (B) may be mixed and used immediately before coating. In this case, the presence of a relatively low molecular weight polyester polyol compound and a large amount of unreacted polyisocyanate component in the coating tends to cause stickiness. In this case, blocking after coating may make winding after coating difficult, and in order to prevent this, a particulate inorganic component may be introduced. In this case, it is particularly preferable to add a plate-like inorganic compound described later from the viewpoint of improving the barrier performance.

(Plate-like inorganic compound)
The resin composition for a coating agent of the present invention may contain a plate-like inorganic compound.
When a plate-like inorganic compound is used in the present invention, it has an effect of improving the coating suitability and reducing the gas barrier property by reducing the adhesiveness.

  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. 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 the scent component 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 polyester polyol (A) or the gas barrier coating agent 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 method for improving the acid resistance of the coating agent layer, a known acid anhydride can be used in combination as an additive. 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.

(Coating agent and other ingredients)
The coating agent of this invention may mix | blend various additives in the range which does not impair gas barrier property. 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.

  Hereinafter, a film coating agent will be described as one of specific applications.

  The coating agent of the present invention can be used as a coating agent for imparting gas barrier properties to a film. Since the film coated with this material is excellent in gas barrier properties, it can be used as a gas barrier film.

  The film using the coating agent 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. Of these, films that have been subjected to stretching treatment are particularly preferred because they can be easily coated and the thickness accuracy can be improved.

  Since the coating agent of the present invention is characterized by having a high gas barrier property, a laminate film formed by the coating agent is used for a PVDC coating layer, a polyvinyl alcohol (PVA) coating 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.

The barrier coating material of the present invention has various barrier functions by making a barrier coating film coated on a base film such as PET, stretched nylon, stretched polypropylene, etc. into a multilayer film adhered to a sealant film with a laminating adhesive. It can be used as a flexible packaging material with the required contents. At this time, if an adhesive having a gas barrier function is used as an adhesive for laminating, a barrier multilayer film having a higher barrier function can be produced.

(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 composed of low molecular weight compounds, for example, scent components such as soy sauce, sauce, miso, lemonene, 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 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) Method for Producing Amorphous Polyester Polyol EGOPA1800 Consisting of Phthalic Anhydride and Ethylene Glycol Phthalic anhydride 148 in a polyester reaction vessel equipped with a stirrer, nitrogen gas inlet tube, rectifying tube, moisture separator, etc. 0.1 part, 75.1 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 1800.

(Production Example 3) 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 4) 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 5) Method for producing amorphous polyester polyol EGoNA600 comprising naphthalene 2,3-dicarboxylic anhydride and ethylene glycol Polyester reaction vessel equipped with stirrer, nitrogen gas introduction tube, rectification tube, water 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 6 Production Method of Polyester Polyol CHDMoPA600 Consisting of Phthalic Anhydride and 1,4-Cyclohexanedimethanol In a polyester reaction vessel equipped with a stirrer, a nitrogen gas introduction tube, a rectification tube, a water separator, etc., phthalic anhydride 148.1 parts of acid, 231.0 parts of 1,4-cyclohexanedimethanol and 0.03 part of titanium tetraisopropoxide were charged and gradually heated so that the upper temperature of the rectification tube did not exceed 100 ° C. 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 7) Method for Producing Polyester Polyol HGoPA600 Containing 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 8 Production Method of Polyester Polyol EGtPA600 Consisting of Terephthalic Acid and Ethylene Glycol 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 9) 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.

  Raw material monomer composition of polyester polyol for Examples obtained in Production Examples 1 to 6, number average molecular weight of resin, content ratio of ortho-oriented aromatic dicarboxylic acid or its anhydride in the raw material monomer with respect to all components of 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 7 to 9, 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 6: Polyester polyurethane synthesis method and coating method
Example 1
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 EGoPA600 synthesized in Production Example 1 was dissolved in 66.8 g of methyl ethyl ketone. Then, it heated at 60 degreeC with the oil bath. Next, 18.8 g of metaxylylene diisocyanate (XDI) was charged into the dropping funnel and dropped 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 hydroxyl group-terminated resin content of 50%. The obtained methyl ethyl ketone solution was used as a coating agent. This coating solution was applied to bar coater NO. 8 is coated on PET film (thickness 12μm, “E-5100” manufactured by Toyobo Co., Ltd.) and uniform coating film without stickiness when the solvent is evaporated and dried with a dryer set at a temperature of 70 ° C. was gotten.

(Example 2)
In a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas inlet tube and a dropping funnel, 54.0 g of the polyester polyol EGoPA1800 synthesized in Production Example 2 was dissolved in 57.8 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a terminal hydroxyl group was obtained in the same manner as in Example 1 except that 3.76 g of metaxylylene diisocyanate (XDI) was used as the isocyanate. When the obtained liquid is used as a coating agent, this coating liquid is applied in the same manner as in Example 1 and the diluted solvent is volatilized and dried with a dryer set at a temperature of 70 ° C. to obtain a uniform coating film without stickiness. It was.

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 NPGoPA600 synthesized in Production Example 3 was dissolved in 37.1 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a terminal hydroxyl group was obtained in the same manner as in Example 1 except that 7.05 g of toluene diisocyanate (TDI) was used as the isocyanate. When the obtained liquid was used as a coating agent, this coating liquid was applied in the same manner as in Example 1, and when the diluted solvent was volatilized and dried with a dryer set at a temperature of 70 ° C., a uniform coating film having no tackiness was obtained. Obtained.

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 EGoPASuA600 synthesized in Production Example 2 was dissolved in 37.3 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a hydroxyl group at the end was obtained in the same manner as in Example 1 except that 7.28 g of hydrogenated metaxylylene diisocyanate (HXDI) was used as the isocyanate. . When the obtained liquid is used as a coating agent, this coating liquid is applied in the same manner as in Example 1 and the diluted solvent is volatilized and dried with a dryer set at a temperature of 70 ° C. to obtain a non-sticky coating film. It was.

(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 EGONA600 synthesized in Production Example 5 was dissolved in 37.5 g of methyl ethyl ketone. A methyl ethyl ketone solution of a polyester polyurethane having a resin content of 50% and having a hydroxyl group at the end was obtained in the same manner as in Example 1 except that 7.5 g of metaxylylene diisocyanate (XDI) was used as the isocyanate. When the obtained liquid is used as a coating agent, this coating liquid is applied in the same manner as in Example 1, and when a diluting solvent is volatilized and dried with a dryer set at a temperature of 70 ° C., a uniform coating film without stickiness is obtained. Obtained.

(Example 6)
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 CHDMMoPA600 synthesized in Production Example 6 was dissolved in 40.4 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 10.4 g of toluene diisocyanate (TDI) was used as the isocyanate. In this solution, 7.0 g of kaolin powder “BARRISURF HX” (manufactured by IMERYS, kaolin / non-swellable, interlayer nonionic, plate-like, average particle size / 1.5 μm, aspect ratio / about 100) is dispersed and inorganic content is contained. The liquid obtained by using the coating liquid containing 18.7% by mass as a coating agent was used as a coating agent. The coating liquid was applied in the same manner as in Example 1, and the dilution solvent was removed with a dryer set at a temperature of 70 ° C. When evaporated and dried, a uniform coating film without stickiness was obtained.

(Examples 7 to 9: two-component mixed coating material)
50/50 of various polyester polyols produced in Production Example 1, Production Example 3 and Production Example 6, "Takenate D-110NB" (trimethylolpropane adduct of metaxylylene diisocyanate) and metaxylylene diisocyanate manufactured by Mitsui Chemicals Mixing and stirring the polyisocyanate-containing curing liquid mixed at a ratio of (weight ratio), methyl ethyl ketone as a solvent, and layered mineral kaolin powder “BARRISURF HX” at the mixing ratio shown in Table 3, a two-component mixed type Coating material. When this coating solution was applied in the same manner as in Example 1 and the diluted solvent was volatilized and dried with a drier set at a temperature of 70 ° C., a non-sticky coating film was obtained.

(Comparative Examples 1-3: Polyester polyurethane synthesis method and coating method)
(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 51.2 g of methyl ethyl ketone. A methyl ethyl ketone solution of a polyester polyurethane having a resin content of 50% and having a hydroxyl group at the end was obtained in the same manner as in Example 1 except that 13.2 g of metaxylylene diisocyanate (XDI) was used as the isocyanate. A reference film was obtained by coating a PET film by the coating method 1 described later using the obtained liquid as a coating agent. When this coating solution was applied in the same manner as in Example 1, and the diluted solvent was volatilized and dried with a dryer set at a temperature of 70 ° C., a non-sticky coating film was obtained.

(Comparative Example 2)
An attempt was made to dissolve 40.0 g of the polyester polyol EGtPA600 synthesized in Production Example 8 in 61.2 g of methyl ethyl ketone in a polyester polyurethane reaction vessel equipped with a stirrer, a nitrogen gas inlet tube, and a dropping funnel, but dissolved at 60 ° C. I did not. Although the temperature was raised and dissolution in a reflux state was attempted, it still could not be dissolved, so that this polyester could not synthesize a polyester polyurethane that could be used as a paint. Further, it could not be obtained as a coating solution.

(Comparative Example 3)
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 EGnPGiPASbA800 synthesized in Production Example 7 was dissolved in 63.2 g of methyl ethyl ketone. A methyl ethyl ketone solution of polyester polyurethane having a resin content of 50% and having a hydroxyl group at the end was obtained in the same manner as in Example 1 except that 15.2 g of toluene diisocyanate (TDI) was used as the isocyanate. A reference film was obtained by coating a PET film by the coating method 1 described later using the obtained liquid as a coating agent. When this coating solution was applied in the same manner as in Example 1, and the diluted solvent was volatilized and dried with a dryer set at a temperature of 70 ° C., a non-sticky coating film was obtained.

(Comparative Examples 4, 5: Two-component mixed coating material)
Using each polyester polyol produced in Synthesis Example 9 and Synthesis Example 11 and the same isocyanate-containing curing liquid as used in Examples 7 to 9, and ethyl acetate as a solvent, and layered kaolin powder “BARRISURF HX” Were mixed according to the formulation shown in Table 4 to obtain a two-component mixed coating material. This coating solution was applied to bar coater NO. After coating with No. 8 and evaporating the diluting solvent with a dryer set at a temperature of 70 ° C. and drying, a non-sticky coating film similar to polyester polyurethane was obtained.

(Comparative Example 6; aqueous emulsion type coating material)
This method relates to an aqueous barrier coating material according to the method of Patent Document 1. Aqueous emulsion type coating material Takelac WBP-341 manufactured by Mitsui Chemicals Co., Ltd. Kunipia F (manufactured by Kunimine Kogyo Co., Ltd., montmorillonite / swelling property, containing sodium ions between layers, plate shape, average particle size / 7 μm, aspect ratio / about 100) per 100 g per 100 g of ion-exchanged water Swelled in 100 g and added. The aqueous dispersion was stirred for 5 minutes at a rotational speed of 2000 rpm with a dispersing device (TK homodisper 2.5 type; manufactured by Primix Co., Ltd.) having a disper blade to obtain a coating material having a swellable layered inorganic compound. This coating solution was applied to bar coater NO. Attempt was made to evaporate and dilute the diluting solvent with a dryer set at a temperature of 70 ° C., but it could not be dried under the same drying conditions as in the previous examples, resulting in an adhesive coating film. It was. Therefore, it was possible to obtain a non-sticky coating layer by additional drying in a dryer set at 60 ° C. for 1 hour.

(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 “◎”.

(4) Drying characteristics The films obtained in various Examples and Comparative Examples were compared with a sensory test by touching with a finger the state immediately after drying with a dryer set at 70 ° C. When the adhesive property does not remain, ○, and when the adhesive property remains ×

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 types and amounts of the polyester polyol, isocyanate, and layered inorganic component used are described. The appearance of the coating liquid was 1 in the case of polyester polyurethane 1-component coating, and 2 in the case of mixed 2-component coating of polyester polyol and polyisocyanate. In addition to these, various evaluation results were described.

  As described above, in the polyester polyurethane coating agent obtained by polymerizing the polyester polyol containing an ortho-oriented aromatic ring and the polyisocyanate containing an aromatic ring or alicyclic structure shown in Examples 1 to 6, a good oxygen barrier, nitrogen An inert gas barrier typified by gas and aroma retention were shown. Also, the drying property was good. Moreover, the various gas barrier property and drying property similar to Examples 1-6 were shown also in the two-component mixed type coating material which mixes the polyester polyol and polyisocyanate shown in Examples 7-9.

  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 expressed. 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 coating agent. In addition, the coating material containing the water-based urethane dispersion of Comparative Example 6 and the water-swellable clay has a certain gas barrier performance, but there is a possibility of problems such as blocking in the coating suitability of the roll in terms of drying properties. Was strongly suggested.

Since the adhesive of the present invention has a gas barrier property such as oxygen, the film coating agent for the packaging material includes various foods and beverage packaging materials, as well as foods and teas having various fragrances and oxygen-degrading components. Scents such as shampoos, rinses, detergents, softeners, soaps, pet foods, insect repellents, fragrances, hair dyes, perfumes, pesticides, various organic solvents, etc. It can be suitably used for flexible packaging materials in fields where it is desired to prevent the release of low molecular components. 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, a coating agent for a protective film for a solar cell, a coating agent for a gas barrier substrate for a display element, a coating agent for a building material, a coating agent for an industrial material, and the like can be suitably used for applications where oxygen barrier properties are desired.

Claims (14)

In a gas barrier coating agent comprising a polyol component, a polyester polyol (A) having two or more hydroxyl groups synthesized from a polycarboxylic acid component, and a polyisocyanate (B) having two or more isocyanate groups,
A polyol component (a1) in which the polyester polyol (A) contains at least one selected from the group consisting of ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, and cyclohexanedimethanol; A gas barrier coating agent comprising a component obtained by polycondensation of a polycarboxylic acid component (a2) containing at least one of ortho-oriented aromatic dicarboxylic acid or anhydride thereof ,
The gas barrier coating agent whose usage rate of ortho-oriented aromatic dicarboxylic acid or its anhydride is 70-100 mass% with respect to all the polycarboxylic acid components. 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 gas barrier coating agent 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 gas barrier coating agent according to claim 1 or 2 , wherein the polyisocyanate (B) contains a polyisocyanate having an aromatic ring or an aliphatic ring. The gas barrier coating agent according to claim 3 , wherein the polyisocyanate having an aromatic ring is metaxylene diisocyanate or a reaction product of metaxylene diisocyanate and an alcohol having two or more hydroxyl groups. The gas barrier coating agent according to claim 3 , wherein the polyisocyanate having an aromatic ring is toluene diisocyanate or a reaction product of toluene diisocyanate and an alcohol having two or more hydroxyl groups. The gas barrier coating agent according to any one of claims 1 to 5 , wherein the gas barrier coating agent further contains a plate-like inorganic compound (C) which is nonionic between layers or non-swellable with respect to water. When the coating amount of the cured coating film obtained from the polyester polyol (A) and the polyisocyanate (B) is about 5 g / m ² , the oxygen permeability of the cured coating film at 23 ° C. and 90% humidity is 50 cc / m ^2. The gas barrier coating agent according to any one of claims 1 to 6 , which is not more than day · atm. When the total mass of the polyester polyol (A), polyisocyanate (B), and plate-like inorganic compound (C) is 100% by mass, the content of the plate-like inorganic compound (C) is 5 to 50% by mass. Item 8. The gas barrier coating agent according to Item 6 or 7 . The gas barrier coating agent according to any one of claims 6 to 8 , wherein the plate-like inorganic compound (C) contains particles having a particle size of 0.1 µm or more. The gas barrier coating agent according to any one of claims 1 to 9 , obtained by dissolving the polyester polyol (A) in a ketone solvent, an ester solvent, or a mixed solvent containing a ketone solvent or an ester solvent. Gas barrier multilayer film using a gas barrier coating agent described as a coating layer to one of claims 1-10. The gas barrier multilayer film according to claim 11 , which has at least a base film layer or a sealant layer in addition to the gas barrier coating agent layer. Gas barrier container used as a coating layer of the gas barrier coating composition according to any one of claims 1 to 12. Gas barrier tube using a gas barrier coating agent described as a coating layer to one of claims 1 to 12.