HK1051545B - Gas barrier compositions having improved barrier properties - Google Patents

Description

Gas barrier composition with improved barrier properties

Technical Field

The present invention relates to gas barrier coating compositions for polymeric packaging materials and to multilayer packaging materials prepared therefrom.

Background

Plastics have increasingly become an alternative material to glass and metal packaging materials. Advantages of plastic packaging materials over glass packaging materials include light weight, low breakage, and low cost. Unlike metal packaging materials, plastic packaging materials can be used to form reclosable containers. However, common plastic packaging materials, such as polyesters, polyolefins and polycarbonates, tend to be gas permeable and problematic when used to package oxygen sensitive items such as food, chemicals or pharmaceutical preparations and/or carbonated beverages.

The degree to which oxygen can permeate a particular plastic packaging material is often expressed as an oxygen permeability constant. The oxygen permeability constant (hereinafter referred to as "P (O)" of these plastic packaging materials that quantifies the amount of oxygen that can pass through the film or coating under specific conditions₂) "), usually in units of cm³-mil/100in²And/atm/day. Specifically, this is the permeation of 100in at a partial pressure differential of 1 atmosphere over a 24 hour period at a specified temperature and relative humidity ("r.h")²(645cm²) Area and 1mil (25.4 μm) thick samples of packaging materialOxygen cm of³Standard units of number measurement. As used herein, P (O) unless otherwise indicated₂) Values are measured at 25 ℃ at 50-55% r.h.

Many foods, beverages, chemicals and pharmaceuticals are susceptible to oxidation which can cause discoloration and/or deterioration. Therefore, these articles must be protectively packaged to prevent their exposure to oxygen. In addition, carbonated beverages must be stored in sealed containers to prevent the escape of "flat tasteless" carbon dioxide gas, which can render the beverage unacceptable. Since oxygen and carbon dioxide can readily permeate through many plastic packaging materials commonly used in the packaging industry, the shelf life of these articles stored in conventional plastic containers is significantly reduced compared to the shelf life of articles stored in glass or metal containers.

Some specific examples of items that are particularly sensitive to oxygen include perishable foods and beverages, such as tomato-based products, e.g., ketchup, and tomato paste, fruit and vegetable juices, and malt beverages, such as beer, wine, and malt (malt liquour). Even short exposure to small amounts of oxygen can adversely affect the color and taste of these products. Specific examples of carbonated beverages whose shelf life is severely reduced if packaged in conventional plastic containers include malt beverages, soft drinks, sparkling waters, sparkling liquors and the like.

One of the most common plastic packaging materials used in the food and beverage industry is poly (ethylene terephthalate) (hereinafter "PET"). Despite its widespread industrial use, PET has a relatively high P (O)₂) A value (i.e., about 6.0). For this reason, the food and beverage industry has sought to improve the P (O) of PET₂) The value is obtained. It should be noted that although P (O)₂) Value refers to the ability of oxygen to permeate through a film or coating, but to reduce P (O)₂) The values improve not only the oxygen barrier properties but also the carbon dioxide barrier properties.

In general, there are two P (O) s that improve plastic packaging materials in the art₂) The method of (1). The plastics themselves may be chemically and/or physically modified. The method is generally usedAre expensive and can present problems during recycling. Further, the packaging material may be coated with a gas barrier material, for example, a gas barrier coating composition or a gas barrier film is applied thereon. The latter process is industrially more attractive than the former process. As it is generally more cost effective and presents little recycling problems.

Many gas barrier coating compositions have been disclosed in the prior art. E.g. with low P (O)₂) Gas barrier coating compositions based on polyepoxide-polyamines of value are disclosed in commonly owned US5,006,361, 5,008,137, 5,300,541, 5,006,381 and WO 95/26997. It is also known in the prior art to have very low P (O)₂) Gas barrier coatings based on polyepoxide-polyamines of value, these coatings also comprising platy fillers such as silica and mica with a defined particle size distribution. The presence of the platy filler in the gas barrier coating composition provides a plastic packaging material with improved barrier properties while maintaining high gloss appearance properties. The above coating compositions have been found to be generally acceptable in the industry as gas barrier coatings for polymeric containers.

For certain applications, gas barrier packaging materials must meet stringent chemical resistance requirements. For example, juice is typically pasteurized at 180 ° F to 190 ° F (82 to 87 ℃) prior to canning. The plastic container formed by the gas-barrier packaging material is filled with the hot product. This process is commonly referred to as the "hot fill process". During the hot-fill process, the gas barrier coating (which has been applied to the plastic container to form the gas barrier packaging material) can be contacted with hot fruit juices, which are typically highly acidic. For these hot-fill applications, the gas barrier packaging material must not only provide gas barrier properties, but must also be chemically resistant.

Hydroxy-substituted aromatic compounds are well known in the art as catalysts for the curing reaction of polyamines with polyepoxides. See alsoAccelerated Amine Curing of Epoxy ResinsGough et al, Research Department, Cray Valley Products, Ltd., reprinted in 43 J.O.C.C.A.409-1960, 6 months, 18 days and aboveCited references. However, it is not known to use these compounds in gas barrier coating compositions to enhance gas barrier properties. Furthermore, the use of these hydroxy-substituted aromatic compounds in thermoplastic polyamine-polyepoxide based gas barrier coating compositions is not known.

The chemical resistance of the above-described gas barrier coatings based on polyamine-polyepoxides can be improved by reducing the amine to epoxide ratio of the composition. However, reducing the amount of polyamines in the composition, while improved chemical resistance can be obtained, also results in packaging materials with low gas barrier properties. From the foregoing, it is apparent that there is a need in the food and beverage packaging industry for chemical resistant packaging materials with improved gas barrier properties.

Summary of The Invention

According to the present invention, there is provided a gas barrier composition comprising a polyamine component (a), a polyepoxide component (B), and a hydroxy-substituted aromatic compound (C). The polyamine component (a) comprises at least one polyamine and the polyepoxide component (B) comprises a polyepoxide having at least two glycidyl groups attached to aromatic units. The hydroxy-substituted aromatic compound (C) is represented by the following structural formula (I):

(I)HO-A-R¹R²

wherein A is arylene; r¹And R²Each independently is H, OH, R³、O(OC)R＇³、NH(CO)R＇³、NH₂、CH₂R⁴、C(CH₃)₂R⁴Or (CO) R⁵Wherein R is³Is an alkyl group; r' 3 is H or alkyl; r⁴Is aryl or amino substituted by hydroxy; r⁵Is (di) hydroxy-substituted aryl; with the proviso that when R¹Is hydrogen or R³When R is²Can not be H or R³The hydroxy-substituted aromatic compound (C) is present in the gas barrier coating composition in an effective amount sufficient to provide oxygen permeability (P (O)₂) Less than or equal to the P (O) of a gas barrier coating provided by the same gas barrier coating composition not comprising the hydroxy-substituted aromatic compound (C)₂) 75% of the total.

A multilayer packaging material having at least one layer of gas permeable packaging material and at least one layer of gas barrier material is also provided. The gas barrier material layer comprises the composition described immediately above. The hydroxy-substituted aromatic compound (C) is present in the gas barrier layer in an effective amount sufficient to provide a gas barrier layer having P (O)₂) Less than or equal to P (O) of a multilayer packaging material comprising a layer of the same gas-permeable packaging material and a layer of the same gas barrier material free of hydroxy-substituted aromatic compounds₂) 75% of the total. A container formed from multiple layers of gas barrier materials is also provided.

Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Further, the term "polymer" as used herein refers to oligomers as well as homopolymers and copolymers.

Detailed description of the invention

The improved gas barrier coating composition of the present invention comprises a polyamine component (A) comprising at least one polyamine, a polyepoxide component (B) comprising at least two glycidyl groups attached to an aromatic unit, and a hydroxy-substituted aromatic compound (C) represented by the above formula (I) wherein the substituent A, R is¹、R²、R³And R⁴As defined in the structure above. A preferably represents phenylene or naphthylene, R¹Represents hydrogen and R²Represents OH or O (OC) R³；R＇³Is H (i.e., acetoxy).

The gas barrier coating composition of the present invention may be a thermosetting composition or a thermoplastic composition.

When the gas barrier coating composition of the present invention is a thermosetting composition, which is preferred, the polyamine component (a) and the polyepoxide component (B) are blended with the hydroxy-substituted aromatic compound (C) as the other component of the composition. When the gas barrier coating composition is a thermoplastic composition, the polyamine component (a) is pre-reacted with the polyepoxide component (B) to form a thermoplastic amine-epoxy resin, which is then mixed with the hydroxy-substituted aromatic compound (C) to form the gas barrier coating composition.

As noted above, hydroxy-substituted aromatic compounds are generally known in the art as catalysts for the curing reaction between a polyamine and a polyepoxide in a thermosetting composition. However, it has surprisingly been found that when a hydroxy-substituted aromatic compound species represented by the above structural formula (I) is included as component (C) in the thermosetting gas barrier coating composition of the present invention, it not only acts as a catalyst for the polyamine-polyepoxide reaction, but also provides enhanced gas barrier properties. Further, when hydroxyl-substituted aromatic compounds are included as component (C) in the gas barrier coating composition of the present invention, it has been found that these hydroxyl-substituted aromatic compounds enhance the gas barrier properties.

The hydroxy-substituted aromatic compound (C) is present in the gas barrier coating composition in an effective amount sufficient to provide oxygen permeability (P (O)₂) Less than or equal to P (O) of the same gas barrier coating composition not including the hydroxy-substituted aromatic compound₂) Preferably lower than or equal to 60%, more preferably lower than or equal to 50%.

In a preferred embodiment of the present invention, the hydroxy-substituted aromatic compound (C) is selected from the group consisting of 2-acetaminophenol, 3-aminophenol, bisphenol A, bisphenol F, resorcinol monoacetate, methylhydroquinone, hydroquinone, catechol, and phloroglucinol. Resorcinol and resorcinol monoacetate are preferred.

The hydroxy-substituted aromatic compound (C) is generally present in the gas barrier coating composition of the present invention in an amount of at least 0.01 weight percent, preferably at least 0.05 weight percent, more preferably at least 0.1 weight percent, and even more preferably at least 0.5 weight percent based on total resin solids in the film-forming coating composition. The hydroxy-substituted aromatic compound (C) is also typically present in the composition of the present invention in an amount of less than 15 weight percent, preferably less than 12 weight percent, more preferably less than 10 weight percent, and even more preferably less than 8 weight percent, based on the total resin solids in the gas barrier coating composition. The amount of hydroxy-substituted aromatic compound (C) present in the gas barrier coating composition of the present invention may range between any combination of these values included in the above numerical values.

As described above, the gas barrier coating composition of the present invention further includes the polyamine component (a) and the polyepoxide component (B). The polyamine component (a) includes at least one polyamine, suitable examples of which include meta-xylylenediamine ("MXDA"), such as Gaskamine 328 and Gaskamine 328S sold by Mitsubishi Gas chemical. The polyamine may further comprise a pre-reacted ungelled amine group-containing adduct having active amine hydrogens.

By "ungelled" is meant that the amine group-containing adduct is substantially free of cross-linking and has an intrinsic viscosity (measured, for example, according to ASTM-D1795 or ASTM-D4243) when dissolved in a suitable solvent. The intrinsic viscosity of the adduct is an indication of molecular weight. On the other hand, the gelling reaction product, due to its substantially infinitely high molecular weight, will have an intrinsic viscosity too high to be measured.

In a preferred embodiment of the present invention, the polyamine is represented by the following structural formula (II)

(II) Φ-(R⁶NH₂)_k

Wherein Φ represents an aryl-containing compound, R⁶Is represented by C₁To C₄Alkyl, k represents a number greater than or equal to 1.5.

k is preferably 1.7 or more, more preferably 1.9 or more, further more preferably 2.0 or more. R⁶Preferably not more than C₃More preferably not more than C₂And still more preferably not more than C₁. Φ generally comprises an aryl group, preferably a phenyl group and/or a naphthalene groupAnd (4) a base.

The gas barrier coating composition of the present invention can be produced without pre-forming the ungelled polyamine adduct. For example, when no polyamine adduct is formed, all of the epoxides (i.e., the polyepoxide component (B), described below) are blended or reacted with the polyamines (i.e., the polyamine component (a)).

When the polyamine component (A) is a pre-reacted, ungelled, amine group-containing adduct having active amine hydrogens, sufficient active amine hydrogen groups must remain unreacted to provide reaction sites with the polyepoxide component (B). In other words, when the gas barrier coating composition is a thermosetting composition, sufficient active amine hydrogens that react with the polyepoxide component (B) during the final curing step must remain. Furthermore, when the gas barrier coating composition is a thermoplastic composition, sufficient active amine hydrogens must remain to react with the polyepoxide component (B) to form a thermoplastic amine-epoxide resin. Typically, from 10 to 80% of the active amine hydrogens of the polyamine are reacted with epoxide groups. Less pre-reacted active amine hydrogens reduce the efficiency of the pre-reaction step and provide less linearity in the polymer product, which is an advantage in the formation of adducts.

According to one embodiment of the present invention, ungelled amine group-containing adducts may be formed by reacting (a) polyamines, such as those described above, with (b) epichlorohydrin. By carrying out this reaction in the presence of a base at a molar ratio of polyamine to epichlorohydrin of greater than 1: 1, the predominant reaction product is a polyamine group attached through a 2-hydroxypropylene chain. The reaction of m-phenylenediamine, a preferred polyamine, with epichlorohydrin is described in US 4,605,765. These products are commercially available from Mitsubishi gas chemical co. under the trade names GASKAMINE 328 * and GASKAMINE * 328S.

In another embodiment, the ungelled amine group-containing adduct is formed by reacting a polyamine (a) with a polyepoxide having a plurality of glycidyl groups attached to aromatic units (c). The term "attached" as used herein refers to the presence of an intermediate linking group.

These polyepoxides can be represented by the following structural formula (III):

wherein R is⁷Is phenylene or naphthylene; x is N, NR⁸、CH₂N、CH₂ NR⁸O and/or C (O) -O, wherein R⁸Is an alkyl group having 1 to 4 carbon atoms, a cyanoethyl group or a cyanopropyl group; n is 1 or 2; m is 2 to 4.

Non-limiting examples of suitable polyepoxides include N, N, N' -tetrakis (oxiranylmethyl) -1, 3-xylylenediamine (e.g., the polyepoxide available as TETRAD X from Mitsubishi Gas Chemical. Co.), resorcinol diglycidyl ether (e.g., HELOXY * 69 available from Shell Chemical Co.), diglycidyl phthalate (e.g., EPI-REZ * A-100 Epoxy Resin available from Shell Chemical Co.), diglycidyl isophthalate, diglycidyl terephthalate, and triglycidyl-p-aminophenol (e.g., Epoxy Resin 0500 available from Ciba-Geigy Corporation).

The reaction of the epoxide with the polyamine (a) to produce the ungelled adduct is conducted at a temperature and concentration of reactants sufficient to produce the desired ungelled product. These temperatures and concentrations vary with the choice of feedstock. However, the reaction temperature is typically from 40 ℃ to 140 ℃, with lower temperatures (e.g., 40 ℃ to 110 ℃) being preferred for those systems that gel more readily. Similarly, the concentration of the reactants in a suitable solvent is typically from 5 to 100 weight percent, depending on the particular molar ratio and type of reactants. Generally lower reactant concentrations are preferred for those systems that gel more easily.

The specific reaction conditions can be readily selected by those skilled in the art in view of the teachings of the disclosure and examples herein. In addition, methods for preparing ungelled amine-functional polymer adducts are also described in commonly owned U.S. Pat. No. 5,006,381, columns 2 to 7.

In many cases, the formation of amine group-containing adducts has the advantage of increasing the molecular weight while maintaining the linearity of the resin, thereby avoiding gelation. This can be achieved by using polyamines having no more than two primary amino groups.

Generally, the polyamine (a) (when used as the sole polyamine component (a)) reacts rather slowly with the polyepoxide component (B). In contrast, the above-described amine group-containing adducts, when used as the sole polyamine component (A), react relatively quickly with the polyepoxide component (B). Thus, the use of the amine group-containing adduct provides the advantage of shortening the reaction time.

The polyepoxide component (B) may be any epoxide known to those skilled in the art to react with the polyamine component (A) to form the gas barrier coating composition of the present invention. The polyepoxide component (B) preferably includes a polyepoxide having a plurality of glycidyl groups attached to aromatic units, such as those represented by the above formula (III). Specific examples of polyepoxides suitable for use as component (B) include those described above which can be reacted with polyamine (a) to form ungelled amine group-containing adducts.

It is to be understood that the polyepoxide used to form the amine group-containing adduct may be the same as or different from the polyepoxide used as the polyepoxide component (B). Typically, if the amine group-containing adduct is used in the gas barrier coating composition of the present invention, the epoxide used to form the amine group-containing adduct and those polyepoxides used as the polyepoxide component (B) have an epoxy functionality of at least 1.4, more preferably at least 2.0. Small amounts of monoepoxides may also be used.

The polyepoxide component (B) may include polyepoxides which are saturated or unsaturated aliphatic, cycloaliphatic, aromatic or heterocyclic and which may be substituted with non-interfering substituents such as hydroxyl or the like. Generally, these polyepoxides may include polyglycidyl ethers of aromatic polyols, which may be formed by etherification of an aromatic polyol with epichlorohydrin or dichlorohydrin (dichlorohydrin) in the presence of a base. Specific examples of these polyepoxides include bis (2-hydroxynaphthyl) methane, 4' -dihydroxybenzophenone, 1, 5-dihydroxynaphthalene, and the like. Polyglycidyl ethers of polyhydric aliphatic alcohols (including cyclic and polycyclic alcohols) are also suitable for use as polyepoxide component (B).

Typically, the polyepoxide component (B) has a molecular weight greater than 80. The molecular weight of the polyepoxide component (B) is preferably from 100 to 1,000, more preferably from 200 to 800. In addition, the polyepoxide component (B) typically has an epoxy equivalent weight (weight) of greater than 40. The equivalent weight of the polyepoxide component (B) is from 60 to 400, more preferably from 80 to 300.

It is to be understood that each amine hydrogen of the polyamine component (a) is theoretically capable of reacting with an epoxy group and is therefore considered to be one amine equivalent. Thus, for the purposes of the present invention, a primary amine nitrogen is considered to be difunctional with respect to the epoxide group.

In the thermosetting gas barrier coating composition of the present invention, the polyamine component (A) and the polyepoxide component (B) are generally present in amounts sufficient to provide a ratio of equivalents of active amine hydrogens in (A) to equivalents of epoxide groups in (B) of 2.0: 1.0 or less, preferably 1.75: 1.0 or less.

When the gas barrier coating composition of the present invention is a thermoplastic composition, the polyamine component (A) and the polyepoxide component (B) are generally present in an amount sufficient to provide a molar ratio of polyamine to polyepoxide in the reaction mixture of from 1.4: 1 to 0.83: 1, preferably from 1.25: 1 to 1.05: 1, more preferably from 1.2: 1 to 1.1: 1. In a preferred embodiment, the thermoplastic gas barrier composition involves reacting a polyamine having two equivalents of primary amino nitrogen per mole (one equivalent per primary amino nitrogen group) with a polyepoxide having an average of two equivalents of epoxy groups per mole (e.g., a reaction between a diamine and a diepoxide).

The reaction product of polyamine component (A) and polyepoxide component (B) preferably contains a significant amount of unreacted amine hydrogens. However, while maximizing the amount of polyamine generally maximizes the gas barrier properties of the resulting gas barrier coating, the concomitant reduction in the amount of polyepoxide present will adversely affect the general film properties of the resulting thermoplastic coating and the crosslink density of the cured or thermoset coating. In contrast, in thermosetting coatings, use of more than the preferred amount of polyepoxide can result in brittle films.

As described above, the chemical resistance of the polyamine-polyepoxide gas barrier coating can be improved by reducing the amount of amine present in the gas barrier coating composition. However, if improved chemical resistance is obtained in this way, there is an accompanying decrease in gas barrier properties. The gas barrier coating composition of the present invention overcomes this reduction in gas barrier properties by incorporating the above-described hydroxy-substituted aromatic compound (C) in the composition.

The gas barrier coating composition of the present invention may be applied to a gas permeable substrate in the form of a solvent-based or water-based coating composition. If a solvent is used, it is selected that is compatible with the substrate being coated and that provides the liquid composition with the desired fluidity during coating. Suitable solvents include oxygenated solvents such as glycol ethers (e.g., 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1-methoxy-2-propanol, etc.), or alcohols such as methanol, ethanol, propanol, etc. More preferred are glycol ethers such as 2-T-oxyethanol and 1-methoxy-2-propanol, of which 1-methoxy-2-propanol is most preferred. The use of 1-methoxy-2-propanol is preferred because of its rapid evaporation rate, thereby keeping a minimum of solvent in the dried or cured film. To achieve the desired flow characteristics in certain embodiments using the pre-reacted adduct, it may be preferred to use 2-butoxyethanol. Furthermore, in embodiments where flow properties are considered and slow evaporation of the solvent is not required, the solvents given herein may be diluted with an inexpensive solvent such as toluene or xylene. The solvent may also include halogenated hydrocarbons. For example, chlorinated hydrocarbons such as methylene chloride, 1, 1, 1-trichloroethane, and the like (generally known as fast evaporating solvents) may be particularly useful for obtaining barrier films. Mixtures of these solvents may also be used. Non-halogenated solvents are preferred, with the resulting barrier material suitably being halogen-free.

The polyamine component (a) may also be in the form of an aqueous solution or dispersion. For example, when the polyepoxide component (B) is water-soluble (e.g., a polyglycidyl ether of an aliphatic diol), the polyamine component (A) can be used in the form of an aqueous solution. In addition, for water-insoluble polyepoxides, the polyamine component (a) can have sufficient amine groups neutralized with an organic acid (e.g., formic acid, lactic acid, or acetic acid) or an inorganic acid (e.g., hydrochloric acid or phosphoric acid) to aid dispersion in an aqueous medium. For these aqueous based systems, organic acids are generally preferred.

The gas barrier coating compositions of the present invention comprising an adduct containing ungelled amine groups generally have a resin solids content of from 15 to 50 wt%, preferably from 25 to 40 wt%, based on the total resin solids weight in the composition. Higher weight percentages can present coating difficulties, particularly with spray coatings, while lower weight percentages generally require removal of large amounts of solvent during the curing stage. For embodiments using a polyamine (e.g., the sole polyamine component (A)) directly reacted with the polyepoxide component (B), solids contents in excess of 50 weight percent can be successfully coated.

The gas barrier coating composition of the present invention may further comprise additives known to those skilled in the art. Some of the more common additives that may be present include inorganic filler particles, pigments, silicones, surfactants and catalysts other than the hydroxy-substituted aromatic compound (C). Each of these optional specific components will be discussed below.

For the inorganic fillers and pigments used, in addition to imparting color and/or hue to the gas barrier material, their use may further enhance the barrier properties of the resulting coating. If used, the weight ratio of pigment to binder is generally not greater than 1: 1, preferably not greater than 0.3: 1, more preferably not greater than 0.1: 1. The binder weight used in these ratios is the total solids weight of the polyamine-polyepoxide resin in the gas barrier coating composition.

Particularly preferred classes of inorganic fillers include platy fillers having a particle size distribution characterized by a number average particle diameter of 5.5 to 15 μm and a volume average particle diameter of 8 to 25 microns. Examples of suitable platy fillers include mica, vermiculite, clay, talc, micaceous iron oxide, silica, platy metals, platy graphite, platy glass, and the like. These plate-like fillers are described in US5,840,825, column 10, line 1 to column 11, line 24.

Siloxanes may be included in the gas barrier coating compositions of the present invention to aid in wetting the substrate on which the barrier material is coated. Generally, the silicone used for this purpose includes various organosiloxanes such as polydimethylsiloxane, polymethylphenylsiloxane and the like. Specific examples include SF-1023 siloxane (polymethylphenylsiloxane, available from General Electric Co.), AF-70 siloxane (polydimethylsiloxane, available from General Electric Co.), and DF-100S siloxane (polydimethylsiloxane, available from BASF Corp.). If used, these siloxanes are typically added to the gas barrier coating composition in amounts of 0.01 to 1.0 weight percent based on the total resin solids in the gas barrier coating composition.

Surfactants can generally be included in a variety of water-based gas barrier coating compositions. Examples of surfactants that may be used for this purpose include any suitable nonionic or anionic surfactant known in the art. If used, these surfactants are typically present in an amount of 0.01 to 1.0 weight percent, based on the total weight of the gas barrier coating composition.

As mentioned above, a catalyst other than the hydroxy-substituted aromatic compound (C) may be included in the gas barrier coating composition of the present invention to facilitate the reaction between the polyamine component (A) and the polyepoxide component (B). Any suitable catalyst commonly used for epoxy-amine reactants may be used for this purpose. Examples of such suitable catalysts include triphenyl phosphite, calcium nitrate, and the like.

When the gas barrier coating composition is a thermosetting composition, the polyamine component (a), the polyepoxide component (B), and the hydroxy-substituted aromatic compound (C) are first thoroughly mixed together before application to a substrate. When the gas barrier coating composition is a thermoplastic composition, the polyamine component (a) is pre-reacted with the polyepoxide component (B) to form a thermoplastic resin, which is then mixed with the hydroxy-substituted aromatic compound (C). After mixing, the gas barrier coating composition can be applied to the substrate immediately, or typically for 1 to 60 minutes, and then applied to improve cure (for thermoset compositions) and/or transparency. This retention time can be reduced and/or eliminated when the polyamine component (a) comprises an amine group-containing adduct or when the solvent used is 2-butoxyethanol.

The gas barrier coating composition can be applied by any conventional method known to those skilled in the art (e.g., spraying, rolling, dipping, brushing, etc.). Preferred coating methods include spray coating and/or dip coating.

After application to a substrate, the thermosetting gas barrier coating composition of the present invention can be cured by allowing it to gradually cure over a period of hours to days at temperatures as low as ambient temperature. However, such low temperature curing is generally slower than the requirements of an industrial production line. It is also not an effective way to remove the solvent from the cured barrier material. Thus, in a preferred embodiment, the oxygen barrier material is cured by heating at as high a temperature as possible without deforming the substrate on which it is coated.

For relatively "slow" solvents (i.e., solvents having a relatively low evaporation rate), the curing temperature may typically be from 55 ℃ to 110 ℃, preferably from 70 ℃ to 95 ℃. At this curing temperature, the curing time is generally from 1 to 60 minutes. For relatively "fast" solvents (i.e., solvents having a relatively high evaporation rate), the curing temperature may typically be 35 ℃ to 70 ℃, preferably 45 ℃ to 65 ℃. At this curing temperature, the curing time is generally from 0.5 to 30 minutes.

After application to a substrate, the thermoplastic gas barrier coating composition of the present invention is typically dried to remove the solvent by heating for a sufficient time and at a temperature sufficient to leave a thin film of the thermoplastic coating. The drying temperature is generally low enough to prevent deformation of the substrate. Typical drying temperatures are 160 ° F (71.1 ℃) to 230 ° F (110 ℃) and drying times are 1 to 60 minutes. Optionally, the film can be dried by drying it at a lower temperature, for example, up to 70F (21.1C) for several days.

The gas barrier coating of the present invention can have any suitable dry film thickness. While thicker coatings generally provide high gas barrier properties, the packaging industry generally prefers thinner coatings for economic reasons. Thus, the gas barrier coatings of the present invention typically have a dry film thickness of no more than 1.0mil (25.4 μm). If thinner films are desired, the gas barrier coatings of the present invention can have a dry film thickness of no more than 0.5mil (12.7 μm) and even no more than 0.3mil (7.6 μm).

The gas barrier coating compositions of the present invention are generally formed to have a P (O) content₂) Not more than 0.5, preferably not more than 0.35 and more preferably not more than 0.25cm³-mil/in²A gas barrier coating of/atm/day.

The gas barrier coatings of the present invention are also quite smooth, transparent and glossy. Gas barrier coatings prepared in accordance with the present invention have a 20 ° gloss of at least 60, preferably at least 70 and more preferably at least 80, as measured with a Gardner Glossgard IIa 20 ° gloss meter available from Gardner Instruments.

The gas barrier coating composition of the present invention is applied as a single layer or multiple layers on a substrate, wherein the solvent is removed from each subsequent layer by multiple heating steps. Both are referred to herein as "multi-layer" packaging materials.

The present invention also provides a multilayer packaging material having improved gas barrier properties. The multilayer packaging material of the present invention comprises at least one layer of a gas permeable substrate and at least one layer of a gas barrier material comprising the above-described polyamine component (a), polyepoxide component (B) and hydroxy-substituted aromatic compound (C). The hydroxy-substituted aromatic compound (C) is present in the gas barrier layer in an effective amount sufficient to provide a gas barrier layer having P (O)₂) Less than or equal to P (O) of a multilayer packaging material comprising a layer of the same gas-permeable substrate and a layer of the same gas barrier material free of hydroxy-substituted aromatic compound₂) Preferably lower than or equal to 60%, more preferably lower than or equal to 50%.

To form the multilayer packaging material of the present invention, the gas barrier coating composition described above may be applied to a suitable substrate. However, it is generally applied to a gas permeable substrate, preferably a polymeric gas permeable packaging material.

The gas permeable material on which the gas barrier coating composition can be applied generally comprises any polymeric material through which gases can readily pass and which can be used as a suitable packaging material. Examples of such suitable gas permeable materials that may be used for packaging food, beverages, chemicals, pharmaceuticals, medical supplies, and the like include polyesters, polyolefins, polyamides, cellulose, polystyrene, and polyacrylics. Polyesters are preferred for their physical properties. Examples of polyesters suitable for this purpose include PET, polyethylene naphthalate ("PEN"), and/or combinations thereof.

In one embodiment of the present invention, the multilayer packaging material comprises a laminate comprising a layer of gas barrier material. To form the laminate, a gas barrier material is applied to a first layer of a suitable substrate, and then a second layer of a similar or different substrate is applied to the layer of gas barrier material.

In embodiments of the invention where a polyolefin (e.g., polypropylene) is used as the gas permeable packaging material, the polyolefin surface is preferably treated to increase surface tension and promote better adhesion of the oxygen barrier material to the polyolefin material. Examples of treatment processes that may be used for this purpose include flame treatment, corona treatment, and the like. Specific examples of these treatments are described by Pinner et al in Plastics: surface and Finish, Butterworth & co., Ltd. (1971), chapter 3.

In another embodiment of the multilayer packaging material completed by the present invention, a sheet or film blank is coated with the above-described gas barrier coating composition and subsequently formed into a container by conventional plastic processing techniques. The coated film or sheet is then formed into articles such as packages, bags, containers, and the like.

In another embodiment of the multilayer packaging material completed by the present invention, a preformed container (e.g. a beverage bottle) is coated with at least one layer of the above-described gas barrier coating composition.

For some applications, with CO₂It is suitable to handle the multilayer packaging material of the invention. Gas barrier coating compositionApplying the coating to a packaging material and then exposing the coating to CO at elevated pressure and temperature₂Under an atmosphere. During this treatment, CO₂Pressure of (2) is typically 30 to 1,000 pounds per inch²(2 bar to 70 bar); the treatment temperature is typically from 32 ° F (0 ℃) to 200 ° F (93 ℃); the treatment time may be 1 minute to 6 weeks. During this treatment, CO₂Preferably 30 to 100 pounds per inch²(2 bar to 7 bar); the treatment temperature is typically from 40 ° F (14 ℃) to 150 ° F (65 ℃); the treatment time may be 1 hour to 3 weeks.

Furthermore, a gas barrier coating is applied to the gas permeable packaging material in the form of a sealable container. The container is then at least partially filled with carbonated beverage and sealed. Since the packaging material is gas permeable, CO₂Can pass through. Thus, carbonated beverages are used as CO₂The medium is treated. For this CO₂The gas permeable material should have P (O) in the treatment method₂) The value is greater than 0.5.

The multilayer packaging material of the present invention is ideally suited for packaging food, beverages, chemicals, pharmaceuticals, pharmaceutical supplies, and the like. The following examples are intended to illustrate the invention, however, these examples should not be construed as limiting the invention in detail. All parts and percentages in the examples, as well as throughout the specification, are by weight unless otherwise indicated.

Examples

Example 1 describes the preparation of an ungelled Mannich base adduct which can be advantageously used as the hydroxy-substituted aromatic compound (C) in the gas barrier coating composition of the present invention.

Examples a to V describe the preparation of thermosetting gas barrier coating compositions. Examples A through N were cured at 180 ℃ F. (82.5 ℃ C.) and examples 0 through V were cured at 145 ℃ F. (62.8 ℃ C.). Comparative examples a and O contained no hydroxy-substituted compound.

Example 2 describes the preparation of a thermoplastic ungelled amine-epoxide adduct which is subsequently used in a thermoplastic gas barrier coating composition as a preformed reaction product of a polyamine component (a) and a polyepoxide component (B). Example 2A describes a comparative thermoplastic gas barrier coating composition containing only the adduct of example 2 without the hydroxy-substituted aromatic compound. Example 2 describes the preparation of a thermoplastic gas barrier coating composition of the present invention containing 5 wt% resorcinol as the hydroxy-substituted aromatic compound (C).

Example 1

This example describes the preparation of an ungelled Mannich base adduct for use as the hydroxy-substituted aromatic compound (C) in gas barrier coating compositions of the present invention.

Into a suitably equipped reactor, 1mol (110g) of resorcinol, 1mol (136g) of m-xylylenediamine and 533g of 1-methyl-2-pyrrolidone were charged. The reaction mixture was heated to a temperature of 30 ℃ under a nitrogen atmosphere and 1mol (30g) of formaldehyde (i.e. 81.1g of 37% aqueous solution) was added over 1 hour. The reaction mixture was held at 40 ℃ for a further 1 hour, then the temperature was raised to 50 ℃ for a further 1 hour. The resulting adduct has a theoretical molecular weight of 258, a theoretical solids content of 30 wt% and a theoretical amine hydrogen equivalent weight of 86.

Examples A to W

Preparation of thermosetting gas Barrier coating compositions

Gas barrier coating compositions of examples a to V were prepared by mixing 17.2 wt% GASKAMINE * 328S (reaction product of m-xylylenediamine with epichlorohydrin, available from Mitsubishi Gas Chemical Co., 70% solution in 1-methoxy-2-propanol (available under the trade name DOWANOL * PM from Dow Chemical Co.), 25.7 wt% tetra-X * (polyglycidyl m-xylylenediamine, available from Mitsubishi Gas Chemical Co., 65% solution in ethyl acetate), 57.0 wt% 1-methoxy-2-propanol and 0.1 wt% SF1023 (silicone surfactant, available from General Electric Co.) under mild stirring.

To the gas barrier compositions of examples B to O and P to V were added the additives (as component (C)) in the amounts given in table 1 below. The compositions of comparative examples a and P contained no additives. The gas barrier coating compositions of examples a to V had a final solids content (based on the total solids of the composition) of about 25 wt%, and a NH to epoxide ratio of 1.0.

Each gas barrier composition prepared as described above was applied to 2mil (50.8 μm) PET film test panels using a 026 wire wound coat applicator. The test panels coated with the compositions of examples A to O were cured at a temperature of 180 ℃ F. (82.5 ℃) and those coated with the compositions of examples P to V were cured at a temperature of 145 ℃ F. (62.8 ℃), the curing time having to be such that they are tack-free (as determined by touch). The coated test panel was then cured for another period of time equal to the time required to reach a tack-free state. The final gas barrier coating film thickness of each cured gas barrier coating composition was about 0.5mil (12.7 μm). The coated test panels were "aged" for 4 days at ambient conditions and then subjected to permeability testing.

Gas permeability test

Each PET test panel prepared as described above was tested for oxygen permeability with OXTRAN 2/20 at 25 ℃ and 50-55% RH. The oxygen permeability constant (P (O)) of the gas barrier material layer of each coated PET sample was calculated by the following equation₂))：

1/R_a＝1/R_b+DFT/P(O₂)

Wherein Ra represents the transfer rate (cm) of the coating film³/100in²/atm/day)；R_bRepresents the film transmission rate of PET; DFT represents the dry film thickness (mil) of the coating; and P (O)₂) Represents the oxygen permeability constant (cm) of the coating³-mil/100in²Atm/day). The test results are given in tables I and II below.

TABLE I

Examples	Additive (wt%)	P(O2)**	Tack free time (minutes @180 ° F)
				A*	Is free of	0.21	15
B*	2% salicylic acid	0.17	9
				C*	2% of water	0.16	18
D*	2% of p-toluenesulfonic acid	0.19	12
				E*	2% phenol	0.19	10
F*	10% Resorcinol DipondensationGlycerol ethers	0.22	13
				G	2% of resorcinol	0.09	10
H	2% of methylhydroquinone	0.07	13
				I	4% of resorcinol	0.07	8
J	2% Hydroquinone	0.04	7
				K	2% of catechol	0.10	6
L	2% phloroglucinol	0.13	7
				M	2% bisphenol A	0.11	10
N	2% bisphenol F	0.13	10
				O	7.5% of the adduct of example 1	0.07	5

Comparative example

** cc-mil/100in²Atm/day at 50-55% R.H. and 25 deg.C

TABLE II

Examples	Additive (wt%)	P(O2)**	Tack free time (minutes @145 ° F)
				P*	Is free of	0.24	35
Q*	2% phenyl salicylate	0.23	25
				R*	2% Resorcinol Monobenzoate	0.24	25
S	2% 2-Acetaminophenol	0.03	19
				T	2% 3-Acetaminophenol	0.12	25
U	2% Resorcinol monoacetate	0.12	25
				V	2% 3-aminophenol	0.13	25

Comparative example

** cc-mil/100in²Atm/day at 50-55% R.H. and 25 deg.C

The data in tables I and II above illustrate that the thermosetting gas barrier coating compositions of the present invention comprising a hydroxy-substituted aromatic compound of a particular structural formula (I) provide a cured gas barrier coating having a gas permeability value that is less than or equal to 75% of the gas permeability of a barrier coating provided by the same composition without the hydroxy-substituted aromatic compound of the particular structural formula (I).

Preparation of thermoplastic gas Barrier coating compositions

Example 2

This example describes the preparation of an ungelled thermoplastic amine-epoxy resin in which a polyamine component (A) is pre-reacted with a polyepoxide component (B) to form an ungelled thermoplastic amine-epoxy adduct.

A suitably equipped reactor was charged with 1mol (136g) of m-xylylenediamine and 835.4g of 1-methyl-2-propanol. The blend was heated to a temperature of 100 ℃ in a nitrogen atmosphere. A mixture of 0.857mol (198.4g) ERISYS RDGE/H (resorcinol diglycidyl ether from CVC specialty Chemicals, Inc. of Maple Shade, N.J.) and 1218.7g 1-methoxy-2-propanol was added over a period of two hours. The reaction mixture was then held at 100 ℃ for 2 hours, then cooled to a temperature of 70 ℃ and vacuum stripped. The resulting amine-epoxy resin had a theoretical molecular weight of 2341, a measured solids content (1 hour @110 ℃) of 36.7 wt%, and a theoretical amine hydrogen equivalent weight of 146.

Examples 2A and 2B

Examples 2A and 2B describe the preparation of two thermoplastic gas barrier coating compositions. Comparative example 2A describes the preparation of a thermoplastic gas barrier coating composition that does not contain a hydroxy-substituted aromatic compound; example 2B describes the preparation of a thermoplastic gas barrier coating composition of the present invention containing 5 wt% resorcinol.

Comparative example 2A

Comparative example 2A consisted of the ungelled thermoplastic amine-epoxy adduct of example 2, which was free of hydroxyl-substituted aromatic compounds.

Example 2B

Example 2B was completed by adding 5 wt% resorcinol to the thermoplastic amine-epoxy adduct of example 2 and reducing the solids content of the resulting thermoplastic gas barrier coating composition to 25 wt% with 1-methoxy-2-propanol.

Each of the compositions of comparative example 2A and example 2B was applied to 2mil PET film test panels using a 020 wire wound film applicator. The coated test panels were dried in an oven at a temperature of 145 ° F (62.8 ℃) for 20 minutes. Oxygen permeability data were then tested with OXTRAN 2/20 immediately without aging, as described above. The gas permeability data are given in table III below.

TABLE III

Example #	P(O2)
		Comparative example 2A	0.59
Example 2B	0.31

The permeability data given in table III above illustrates that including resorcinol as the hydroxy-substituted aromatic compound (C) in a thermoplastic gas barrier coating composition provides significantly improved gas barrier properties compared to the same composition without the hydroxy-substituted aromatic compound.

Claims (44)

1. A gas barrier coating composition comprising

(A) A polyamine component comprising at least one polyamine, wherein the polyamine is represented by the following structural formula (II):

(II)Φ-(R⁶NH₂)_k

wherein Φ represents an aryl-containing compound,

R⁶is represented by C₁To C₄An alkyl group, a carboxyl group,

k represents a number greater than or equal to 1.5;

(B) a polyepoxide component comprising a polymer having at least two glycidyl groups attached to aromatic units; and

(C) a hydroxy-substituted aromatic compound represented by the following structural formula (I):

(I)HO-A-R¹R²

wherein A is aryl; r¹And R²Each independently is H, OH, R³、O(OC)R′³、NH(CO)R′³、NH₂、CH₂R⁴、C(CH₃)₂R⁴Or (CO) R⁵，

Wherein R is³Is an alkyl group; r'³Is H or alkyl; r⁴Is aryl or amino substituted by hydroxy; and R⁵Is a dihydroxy-substituted aryl group with the proviso that when R is¹Is hydrogen or R³When R is²Is not H or R³And are and

wherein the hydroxy-substituted aromatic compound (C) is present in the gas barrier coating composition in an effective amount sufficient to provide P (O) having oxygen permeability₂) Less than or equal to the oxygen permeability P (O) of a gas barrier coating provided by the same gas barrier coating composition without the hydroxy-substituted aromatic compound₂) 75% of the total.

2. The gas barrier coating composition of claim 1, wherein R⁶Represents an alkyl group having not more than 2 carbon atoms, and k represents a number greater than or equal to 1.9.

3. The gas barrier coating composition of claim 1, wherein the polyamine is m-xylylenediamine.

4. The gas barrier coating composition of claim 1, wherein the polyamine component (a) is an ungelled amine group-containing adduct comprising the reaction product of a polyamine (a) with at least one of the following components:

(b) epichlorohydrin, and

(c) polyepoxides having at least two glycidyl groups attached to aromatic units.

5. The gas barrier coating composition of claim 4, wherein 10 to 80% of the active amine hydrogens of the ungelled amine group-containing adduct are reacted with the epoxy groups of (B) and/or (c) prior to reaction with the polyepoxide (B) component.

6. The gas barrier coating composition of claim 4, wherein the polyamine component (A) comprises an ungelled amine group-containing adduct that is the reaction product of polyamine (a) and epichlorohydrin.

7. The gas barrier coating composition of claim 4, wherein the polyamine component (A) comprises an ungelled amine group-containing adduct that is the reaction product of a polyamine (a) and a polyepoxide having at least two glycidyl groups attached to aromatic units.

8. The gas barrier coating composition of claim 7, wherein the polyepoxide having at least two glycidyl groups attached to aromatic units is represented by the following structural formula (III):

wherein

R⁷Is an arylene group;

x is N, NR⁸、CH₂N、CH₂NR⁸O or C (O) -O,

wherein R is⁸Is an alkyl group having 1 to 4 carbon atoms, a cyanoethyl group or a cyanopropyl group;

n is 1 or 2;

m is 2 to 4.

9. The gas barrier coating composition of claim 8, wherein R⁷Is phenylene or naphthylene.

10. The gas barrier coating composition of claim 8, wherein the polyepoxide having at least two glycidyl groups attached to aromatic units comprises at least one selected from the group consisting of N, N' -tetrakis (oxiranylmethyl) -1, 3-xylylenediamine, resorcinol diglycidyl ether, diglycidyl phthalate, diglycidyl isophthalate, diglycidyl terephthalate, and triglycidyl p-aminophenol.

11. The gas barrier coating composition of claim 4, wherein the polyamine (a) comprises m-xylylenediamine.

12. The gas barrier coating composition of claim 1, wherein the polyepoxide (B) comprises a polyepoxide represented by the following structural formula (III):

wherein

R⁷Is an arylene group;

x is N, NR⁸、CH₂N、CH₂NR⁸O or C (O) -O,

wherein R is⁸Is an alkyl group having 1 to 4 carbon atoms, a cyanoethyl group or a cyanopropyl group;

n is 1 or 2; and

m is 2 to 4.

13. The gas barrier coating composition of claim 12, wherein R⁷Is phenylene or naphthylene.

14. The gas barrier coating composition of claim 12, wherein the polyepoxide (B) comprises at least one polyepoxide selected from the group consisting of N, N' -tetrakis (oxiranylmethyl) -1, 3-xylylenediamine, resorcinol diglycidyl ether, diglycidyl phthalate, diglycidyl isophthalate, diglycidyl terephthalate, and triglycidyl-p-aminophenol.

15. The gas barrier coating composition of claim 1, wherein the hydroxy-substituted aromatic compound (C) is selected from the group consisting of 2-acetamidophenol, 3-aminophenol, bisphenol a, bisphenol F, resorcinol monoacetate, methylhydroquinone, hydroquinone, catechol, and phloroglucinol.

16. The gas barrier coating composition of claim 1, wherein (C) is a Mannich base compound comprising the reaction product of resorcinol, a carbonyl-containing compound, and an amine.

17. The gas barrier coating composition of claim 1, wherein the hydroxy-substituted aromatic compound (C) is present in an amount of 0.1 to 10 weight percent based on total resin solids weight of the coating composition.

18. The gas barrier coating composition of claim 1, wherein the composition is a thermosetting composition.

19. The gas barrier coating composition of claim 1, wherein P (O) is formed having oxygen permeability₂) Not more than 0.5cm³-mil/in²A gas barrier coating of/atm/day.

20. The gas barrier coating composition of claim 1, wherein the composition is a thermoplastic coating composition.

21. A multilayer packaging material having at least one gas permeable packaging material layer and at least one gas barrier material layer, said gas barrier material layer comprising:

(A) a polyamine component comprising at least one polyamine, wherein the polyamine component (a) comprises a polyamine represented by the following structural formula (II):

(II)Φ-(R⁶NH₂)_k

wherein Φ represents an aryl-containing compound,

R⁶is represented by C₁To C₄An alkyl group, a carboxyl group,

k represents a number greater than or equal to 1.5;

(B) a polyepoxide component comprising a polyepoxide having at least two glycidyl groups attached to aromatic units; and

(C) a hydroxy-substituted aromatic compound represented by the following structural formula (I):

(I)HO-A-R¹R²

wherein A is aryl; r¹And R²Each independently is H, OH, R³、O(OC)R′³、NH(CO)R′³、NH₂、CH₂R⁴、C(CH₃)₂R⁴Or (CO) R⁵，

Wherein R is³Is an alkyl group; r'³Is H or alkyl; r⁴Is aryl or amino substituted by hydroxy; and R⁵Is a dihydroxy-substituted aryl group with the proviso that when R is¹Is hydrogen or R³When R is²Is not H or R³，

Wherein the hydroxy-substituted aromatic compound (C) is present in the layer of gas barrier material in an effective amount sufficient to provide P (O) having oxygen permeability₂) Less than or equal to P (O) of a multilayer packaging material comprising a layer of the same gas-permeable packaging material and a layer of the same gas barrier material free of hydroxy-substituted aromatic compounds₂) 75% of the total.

22. The multilayer packaging material of claim 21, wherein R⁶Represents an alkyl group having not more than 2 carbon atoms, and k represents a number greater than or equal to 1.9.

23. The multilayer packaging material of claim 21 wherein the polyamine is m-xylylenediamine.

24. The multi-layer packaging material of claim 21 wherein polyamine component (a) comprises an ungelled amine group-containing adduct comprising the reaction product of polyamine (a) with at least one of the following components:

(b) epichlorohydrin, and

(c) polyepoxides having at least two glycidyl groups attached to aromatic units.

25. The multilayer packaging material of claim 24 wherein 10 to 80% of the active amine hydrogens of the ungelled amine group-containing adduct are reacted with the epoxy groups of (B) and/or (c) prior to reaction with the polyepoxide component (B).

26. The multi-layer packaging material of claim 24 wherein the polyamine component (a) comprises an ungelled amine group-containing adduct which is the reaction product of a polyamine (a) and epichlorohydrin.

27. The multilayer packaging material of claim 24 wherein the polyamine component (a) comprises an ungelled amine group-containing adduct that is the reaction product of a polyamine (a) and a polyepoxide having at least two glycidyl groups attached to aromatic units.

28. The multilayer packaging material of claim 27 wherein the polyepoxide having at least two glycidyl groups attached to aromatic units is represented by the following structural formula (III):

wherein

R⁷Is an arylene group;

x is N, NR⁸、CH₂N、CH₂NR⁸O or C (O) -O,

wherein R is⁸Is an alkyl group having 1 to 4 carbon atoms, a cyanoethyl group or a cyanopropyl group;

n is 1 or 2;

m is 2 to 4.

29. The multilayer packaging material of claim 28, wherein R⁷Is phenylene or naphthylene.

30. The multilayer packaging material of claim 28 wherein the polyepoxide having at least two glycidyl groups attached to aromatic units comprises at least one member selected from the group consisting of N, N' -tetrakis (oxiranylmethyl) -1, 3-xylylenediamine, resorcinol diglycidyl ether, diglycidyl phthalate, diglycidyl isophthalate, diglycidyl terephthalate, and triglycidyl p-aminophenol.

31. The multilayer packaging material of claim 24 wherein the polyamine (a) that reacts to form the ungelled amine group-containing adduct comprises m-xylylenediamine.

32. The multilayer packaging material of claim 21 wherein the polyepoxide component (B) comprises a polyepoxide represented by the following structural formula (III):

wherein

R⁷Is an arylene group;

x is N, NR⁸、CH₂N、CH₂NR⁸O or C (O) -O,

wherein R is⁸Is an alkyl group having 1 to 4 carbon atoms, a cyanoethyl group or a cyanopropyl group;

n is 1 or 2; and

m is 2 to 4.

33. The multilayer packaging material of claim 32, wherein R⁷Is phenylene or naphthylene.

34. The multilayer packaging material of claim 32 wherein the polyepoxide (B) comprises at least one polyepoxide selected from the group consisting of N, N' -tetrakis (oxiranylmethyl) -1, 3-xylylenediamine, resorcinol diglycidyl ether, diglycidyl phthalate, diglycidyl isophthalate, diglycidyl terephthalate, and triglycidyl-p-aminophenol.

35. The multilayer packaging material of claim 21 wherein the hydroxy-substituted aromatic compound (C) is selected from the group consisting of 2-acetamidophenol, 3-aminophenol, bisphenol a, bisphenol F, resorcinol monoacetate, methylhydroquinone, hydroquinone, catechol, and phloroglucinol.

36. The multilayer packaging material of claim 21 wherein (C) is a Mannich base compound comprising the reaction product of resorcinol, a carbonyl-containing compound, and an amine.

37. The multilayer packaging material of claim 21 wherein the hydroxy-substituted aromatic compound (C) is present in an amount of 1 to 10 weight percent based on the weight of total resin solids of the gas barrier material layer.

38. The multilayer packaging material of claim 21, wherein said layer of gas barrier material comprises a thermoplastic material.

39. The multilayer packaging material of claim 21 wherein the layer of gas barrier material has an oxygen permeability P (O)₂) Not more than 0.25cm³-mil/in²/atm/day。

40. The multilayer packaging material of claim 21 wherein said gas permeable packaging material layer comprises a material selected from the group consisting of polyesters, polyolefins, polyamides, cellulose, polystyrene and polyacrylic materials.

41. A multilayer packaging material of claim 40, wherein said layer of gas permeable packaging material comprises a polyester material.

42. A multilayer packaging material of claim 40, wherein said gas permeable packaging material layer comprises at least one of polyethylene terephthalate and polyethylene naphthalate.

43. The multi-layer packaging material of claim 40, wherein said multi-layer packaging material is in the form of a sealable container.

44. The multi-layered packaging material of claim 43, wherein said sealable container is a beverage container.