KR102432490B1 - A method of manufacturing of instant rice packing materials using transparent deposition Nylon - Google Patents

Abstract

The present invention relates to a novel functional gas barrier transparent deposition nylon film and a gas barrier laminate comprising the same which has high heat resistance required for boiled and retort foods, such as instant rice and porridge, and excellent gas barrier properties to extend freshness and shelf life of foods in food flexible packaging materials. According to the present invention, a gas barrier film comprises: a polyamide-based plastic film; a gas barrier deposition layer installed on the film and containing an inorganic compound; and organic-inorganic coating layer installed and laminated on the gas barrier deposition layer and formed of a gas barrier coating composition containing a dispersion of silica nanoparticles and an acrylic polymer based on methyl methacrylate polymerized with a monomer having specific components and contents. The gas barrier laminate comprising the gas barrier film is laminated in a dry lamination process or an extrusion lamination process to reinforce heat resistance and thus, has excellent gas barrier properties even when stored for a long time under high temperature and high humidity.

Description

A method of manufacturing instant rice packing materials using transparent deposition Nylon

The present invention provides a new functional gas barrier transparent vapor deposition nylon film having high heat resistance required for boiling, retort food, etc., and excellent gas barrier properties for extending the freshness and shelf life of food in flexible food packaging materials and the same It relates to a gas barrier laminate comprising: lamination is made in a dry lamination process or an extrusion lamination process to enhance heat resistance, and thus has excellent gas barrier properties even when stored for a long time under high temperature and high humidity.

Conventional food packaging materials use polyvinyl alcohol (PVA) coating, ethylene-vinyl alcohol (EVOH) film, metal-deposited polyethylene terephthalate (vmPET) film, aluminum foil (Al Foil), etc. have been protecting Gas barrier properties for content protection vary depending on the material, and polyvinyl alcohol coating is highly dependent on temperature and humidity and has a problem that it cannot maintain sufficient gas barrier properties. has been using However, the use of such aluminum foil is currently known as a material that is difficult to completely recycle due to the problem of ash remaining during incineration. Alternatively, a metal-deposited polyethylene terephthalate (vmPET) film is used, but the gas barrier property is excellent, but there is a problem that the contents cannot be confirmed or the elasticity is poor because it is opaque.

On the other hand, a gas barrier film used for boiling or retort food such as instant rice and porridge must have water resistance and moisture resistance and considerable heat resistance at the same time because it is accompanied by processing such as boil and retort sterilization. Currently, ethylene-vinyl alcohol film is used as a gas barrier film for boiling and retort food applications. However, the ethylene-vinyl alcohol film also had poor heat resistance and was vulnerable to moisture, so there was a limit to the processing method. In addition, the ethylene-vinyl alcohol film has a strong stiffness, so pinholes are easy to occur, and the heat of polyethylene oxidation during processing at a high temperature degrades the ethylene-vinyl alcohol film, thereby reducing gas barrier properties.

In order to improve this problem, an inorganic compound deposition layer composed of metal oxides such as aluminum oxide, magnesium oxide, and silicon oxide is installed on a plastic film, and a coating layer is formed to compensate for defects in the deposition layer and protect the deposition layer. Gas barrier films are being investigated.

Here, in order to further improve gas barrier properties, a gas barrier film having a coating layer formed by curing an epoxy resin composition containing an epoxy resin, an epoxy resin curing agent, and non-spherical inorganic particles has been proposed (Patent Document 1).

Moreover, in order to improve adhesiveness with a base material, the gas-barrier film which is laminated|stacked through an anchor-coat layer, and the anchor-coat layer is a layer which consists of a hardened|cured material of the composition containing the acrylic resin which has an organic acid group has been proposed (patent document 2). ).

However, the gas barrier film having a coating layer formed by curing the epoxy resin composition does not have sufficient heat resistance required for retort foods, so there is a problem in that the gas barrier property is deteriorated. In the case of a cured product of the composition containing the composition, there was a problem in that although the effect of improving the adhesion was improved, the degree of improving the gas barrier properties was not large.

In addition, in order to express high oxygen barrier properties, a gas barrier laminate is proposed in which an organic-inorganic coating layer is formed using a polymer containing a hydrolyzable alkoxysilane and a carboxyl group, and the carboxyl group is neutralized with a metal ion (Patent Document 3) .

However, although high oxygen barrier properties were initially exhibited, a phenomenon in which gas barrier properties were significantly deteriorated after retort treatment still occurred.

As such, it is difficult to satisfy the high heat resistance and gas barrier properties required by the prior art to achieve both high heat resistance and gas barrier properties required for boiling, retort food, etc., such as instant rice and porridge. It is necessary to withstand the current, so better properties are required. In addition, it is required to make the gas barrier layer thin to prevent deterioration of gas barrier properties during processing such as printing and lamination and to exhibit the mechanical properties inherent in the base film of the gas barrier laminate.

Republic of Korea Patent Publication No. 10-2019-0094157 (published on August 12, 2019) Republic of Korea Patent Publication No. 10-2019-0098962 (published on August 23, 2019) Republic of Korea Patent Publication No. 10-1220103 (published on December 22, 2010)

In order to solve the above problems, the present invention has gas barrier properties under high temperature and high humidity, is eco-friendly, can see through the contents, and secures higher high temperature thermal stability than conventional barrier materials to maintain excellent heat resistance and gas barrier An object of the present invention is to provide a film that does not deteriorate in properties and a gas barrier laminate with reinforced heat resistance.

The problems to be solved in the present invention are not limited to the above technical problems, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description.

As a result of intensive studies conducted by the present inventor under the above subject, heat is applied when sterilizing together with the packaging material during the manufacturing process of boiling or retort foods such as instant rice and porridge, resulting in a decrease in the gas barrier properties of the food flexible packaging material. could see that That is, when an organic-inorganic coating layer is formed using hydrolyzable silane, alcohol remains as a residual component due to hydrolysis of the silane, and the alcohol becomes a gas by heat, thereby reducing barrier properties. As a result of the study conducted by the present inventor under the above task, methyl methacrylate-based acrylic polymer that is polymerized into a monomer having a specific component and content while securing gas barrier properties by depositing an inorganic compound on a polyamide-based plastic film; And when a composition comprising a silica nanoparticle dispersion is coated and used, it has thermal stability even at a high temperature, and it was found that the barrier property deterioration does not occur even in the lamination process, leading to completion of the present invention.

The present invention relates to a polyamide-based plastic film, a gas barrier deposition layer provided on the film and containing an inorganic compound, and a gas barrier coating composition installed on the gas barrier deposition layer and comprising an acrylic polymer and silica nanoparticle dispersion. The organic-inorganic coating layer to be formed is laminated, and the acrylic polymer is at least one selected from alkyl (meth)acrylate monomers having C1-C15 carbon atoms in the alkyl group based on 100 parts by weight of the total monomer 70 to 90 parts by weight, (b) a total of 1 to 10 parts by weight of at least one or more monomers selected from copolymerizable monomers containing a hydroxyl group, and (c) a sum of at least one or more monomers selected from copolymerizable monomers containing a carboxyl group It is an acrylic polymer polymerized by including 5 to 25 parts by weight, and among the alkyl (meth)acrylate monomers, methyl methacrylate is a gas barrier coating composition comprising at least 30 parts by weight or more. Gas barrier film is about

According to another aspect of the present invention, the gas barrier film, a sealant film provided on the back of the plastic film of the gas barrier film, and a printing film provided on the back of the organic-inorganic coating layer of the gas barrier film, characterized in that the gas barrier laminate is provided do.

In addition, the gas barrier film, the sealant film provided on the plastic film back side of the gas barrier film, and the printing film provided on the back surface of the organic-inorganic coating layer of the gas barrier film, the printing film, the gas barrier film, and the sealant film are for dry lamination Disclosed is a gas barrier laminate with reinforced heat resistance, characterized in that the lamination is made by an adhesive and the oxygen permeability is maintained at 0.7cc/m ² ·day or less even after lamination.

In addition, the gas barrier film, the sealant film provided on the back of the plastic film of the gas barrier film, and a printing film installed on the back of the organic-inorganic coating layer of the gas barrier film, wherein the printing film, the gas barrier film, and the sealant film are polyethylene-based resins Disclosed is a gas barrier laminate with reinforced heat resistance, characterized in that the lamination is made by extruding at a high temperature of 280 to 320° C. and the oxygen permeability is maintained at 0.7 cc/m ² ·day or less even after lamination.

According to another aspect of the present invention, the method comprising: forming a gas barrier deposition layer containing an inorganic compound directly on a polyamide-based plastic film or through an anchor coat layer; preparing a gas barrier coating composition as described above comprising an acrylic polymer and a silica nanoparticle dispersion; preparing the gas barrier film described above by applying the coating composition directly on the gas barrier deposition layer or through an anchor coat layer to form an organic-inorganic coating layer; forming an adhesive layer in a dry adhesive state by applying an adhesive for dry lamination to the backside of the plastic film and/or the backside of the organic-inorganic coating layer and evaporating to dryness at 70 to 90°C; Laminating the sealant film by pressure bonding to the adhesive layer of the plastic film, and pressure bonding the printing film to the adhesive layer of the organic-inorganic coating layer; A gas barrier laminate with reinforced heat resistance, characterized in that the laminated laminate is aged at 40 to 50° C. for 3 to 7 days; A method of manufacturing is provided.

According to another aspect of the present invention, the method comprising: forming a gas barrier deposition layer containing an inorganic compound directly on a polyamide-based plastic film or through an anchor coat layer; preparing a gas barrier coating composition as described above comprising an acrylic polymer, and a dispersion of silica nanoparticles; preparing the gas barrier film described above by applying the coating composition directly on the gas barrier deposition layer or through an anchor coat layer to form an organic-inorganic coating layer; Putting a polyethylene-based resin into an extruder and melt-extruding it at a high temperature of 280 to 320° C. to form a first adhesive layer on one surface of the printing film, while integrally bonding the gas barrier film to the back surface of the first adhesive layer and laminating; and putting a polyethylene-based resin into an extruder on the back side of the gas barrier film and melt-extruding it at a high temperature of 280 to 320° C. to form a second adhesive layer while simultaneously laminating a sealant film on the back surface of the second adhesive layer. There is provided a method of manufacturing a gas barrier laminate with reinforced heat resistance, characterized in that the film, the gas barrier film, and the sealant film are laminated through an extrusion lamination process.

According to another aspect of the present invention, there is provided a ready-to-eat food packaging material for boiling and retort comprising the gas barrier film.

Since the gas barrier film of the present invention has a structure in which an organic-inorganic coating layer is formed on the polyamide-based plastic film deposition layer, the coating layer protects the deposition layer and improves gas barrier properties, so that it has thermal stability at high temperatures and lowered barrier properties even in the lamination process , and high gas barrier properties can be achieved.

In addition, since the gas barrier film of the present invention uses a gas barrier deposition layer containing an inorganic compound, it is possible to form a thin gas barrier layer while exhibiting the mechanical properties inherent in the polyamide-based plastic film.

According to the present invention, it is possible to achieve both high heat resistance and gas barrier properties, and a gas barrier film having excellent laminate strength, bending resistance and tensile resistance, and a gas barrier laminate using the same are obtained.

When the gas barrier film and the laminate of the present invention are used, it is possible to provide an instant food packaging material having water resistance and moisture resistance suitable for use in packaging materials for boiling and retort foods such as instant rice and porridge, and at the same time having considerable heat resistance. .

When a laminate is manufactured by a dry lamination process or an extrusion lamination process using the gas barrier film of the present invention, the organic-inorganic coating layer is cured again without deterioration in gas barrier properties even at high temperatures, and the heat resistance is further strengthened. It is possible to provide a packaging material with more reinforced durability and heat resistance.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the gas barrier film of this invention.
2 is a cross-sectional view showing an example of the gas barrier laminate of the present invention.
3 is a cross-sectional view showing another example of the gas barrier laminate of the present invention.
4 is an exemplary view showing the manufacturing process and equipment of the gas barrier laminate by the dry lamination process of the present invention.
5 is an exemplary view showing the manufacturing process and equipment of the gas barrier laminate by the extrusion lamination process of the present invention.

Hereinafter, specific content for carrying out the present invention will be described in detail. In this specification, (meth)acrylate is used by the meaning including both an acrylate and a methacrylate.

The gas barrier film of the present invention includes a polyamide-based plastic film, a gas barrier deposition layer disposed on the film and containing an inorganic compound, and a gas disposed on the gas barrier deposition layer and containing an acrylic polymer and silica nanoparticle dispersion. An organic-inorganic coating layer formed of a barrier coating composition is laminated, and the acrylic polymer is at least one selected from (a) an alkyl (meth)acrylate monomer having a C1-C15 alkyl group based on 100 parts by weight of the total monomer. A total of 70 to 90 parts by weight of a monomer, (b) a total of 1 to 10 parts by weight of at least one or more monomers selected from copolymerizable monomers containing a hydroxyl group, and (c) at least 1 selected from copolymerizable monomers containing a carboxyl group It is an acrylic polymer polymerized including 5 to 25 parts by weight of a total of 5 to 25 parts by weight of more than one monomer, and among the alkyl (meth) acrylate monomers, methyl methacrylate is a gas barrier coating composition comprising at least 30 parts by weight or more do.

The gas barrier film of the present invention deposits an inorganic compound on a plastic film to secure gas barrier properties and at the same time coat a composition containing a dispersion of an acrylic polymer and silica nanoparticles polymerized with a monomer having a specific component and content to form a deposition layer. It has thermal stability at high temperatures by improving gas barrier properties while protecting, and high gas barrier properties can be achieved without lowering barrier properties even in the lamination process.

As shown in FIG. 1, the gas barrier film 100 of the present invention includes, for example, an inorganic compound deposited layer 20 installed on a polyamide-based plastic film 10, and a gas barrier coating layer 30 coated thereon. It has a sequentially stacked configuration. In addition, the oxygen permeability of the gas barrier film is 0.7 cc/m ² ·day or less, and can be preferably used as a packaging material for food requiring long-term storage. Oxygen permeability was measured under conditions of a temperature of 23°C and a relative humidity of 0% in accordance with ASTM D3985 using an oxygen permeability measuring device (OXTRAN-22 manufactured by MOCON Corporation).

[Polyamide-based plastic film]

The plastic film used in the gas barrier film of the present invention uses a polyamide-based film, and various materials are appropriately added depending on the type of contents to be packaged, mechanical strength, chemical resistance, solvent resistance, and manufacturability required for moving and storage. can be applied. Polyamide-based films such as various nylons are used as instant food packaging materials for boiling and retort of the present invention in consideration of characteristics such as heat resistance, mechanical strength (elasticity of the film, abrasion from the outside, puncture strength), and weather resistance. In particular, nylon film is more suitable because it has excellent impact resistance and pinhole resistance. In addition, when manufacturing a laminate by the dry lamination process or extrusion lamination process, it has sufficient heat resistance so that the gas barrier property does not deteriorate even at high temperatures, and is sterilized together with packaging materials during the manufacturing process of boiling and retort foods such as instant rice and porridge. It is possible to prevent deterioration of the gas barrier properties of the flexible packaging material due to the application of heat.

Although there is no restriction|limiting in particular as for the thickness of a film, If it is a nylon film, about 10-30 micrometers is practical. It is preferable to use a stretched nylon film having a thickness of 15 μm or more for producing a laminate having pinhole resistance and heat resistance. However, since the nylon film is vulnerable to moisture and the gas barrier property is lowered when the humidity increases, a gas barrier deposition layer containing an inorganic compound is formed to maintain the high gas barrier property even at high humidity.

[Gas barrier deposition layer containing inorganic compound]

In the gas barrier deposition layer containing the inorganic compound of the present invention, an inorganic compound deposition layer having a film thickness of 10 nm or more is formed on one side of the plastic film surface, preferably 15 nm to 45 nm. More preferably, it is formed in 20 nm to 30 nm. Below 10 nm, the gas barrier property is insufficient, and even if it exceeds 45 nm, the gas barrier performance reaches a limit, and the cohesive energy during deposition increases and the plastic film may be deformed by heat.

The deposition method may be carried out by a known method such as a physical method or a chemical method, but the physical method is more preferable from the viewpoint of productivity, and the physical method includes a vacuum evaporation method, a sputter deposition method, an ion plating method, etc. , in particular, it is more preferable to use a vacuum deposition method. Methods such as resistance heating, high-frequency heating, and electron beam heating can be applied to the heating and evaporation of the material for this purpose. In these methods, the metal oxide deposition layer can be formed relatively easily by introducing a reactive gas such as oxygen during evaporation of the metal material in the deposition chamber. A plastic film is generally elongate, is supplied in roll shape, is unwound from a roll in a vacuum chamber, vapor deposition is performed, and is wound up again in roll shape.

In this embodiment, in particular, a resistance heating vacuum vapor deposition method, an electron beam heating vacuum vapor deposition method, or the like is preferably used.

The inorganic compound preferably has transparency, and one or two inorganic transparent oxides selected from the group consisting of AlOx, AlNx, AlOxNy, TiOx, SiOx, ZnOx, SnOx, SiNx, SiOxNy, NiOx and MgO may be used. . Among them, it is more preferable to use aluminum oxide, which is AlOx, from the viewpoint of processability, heat resistance and gas barrier properties.

In addition, the vapor deposition layer may consist of two or more layers having the same or different composition, so that a gas barrier film having various characteristics can be produced by sharing the intended action. Even if the gas barrier film according to the present embodiment is provided with a vapor deposition layer containing an inorganic compound, it has good durability against external forces such as bending or stretching, and a decrease in barrier properties when the external force is applied is suppressed.

[Gas barrier organic-inorganic coating layer]

In the present invention, the gas barrier organic-inorganic coating layer is formed by applying a composition comprising a newly polymerized acrylic polymer and a silica nanoparticle dispersion. The acrylic polymer is a total of 70 to 90 parts by weight of at least one or more monomers selected from alkyl (meth)acrylate monomers having C1-C15 carbon atoms in the alkyl group, (b) a hydroxyl group based on 100 parts by weight of the total monomer. 1 to 10 parts by weight of at least one or more monomers in total selected from copolymerizable monomers including, and (c) 5 to 25 parts by weight of at least one or more monomers in total selected from copolymerizable monomers containing a carboxyl group. It is a polymer, and among the alkyl (meth)acrylate monomers, methyl methacrylate is included in a proportion of at least 30 parts by weight or more. The gas barrier organic-inorganic coating layer protects the deposition layer, which is the underlying layer, to improve gas barrier properties, and at the same time exhibit gas barrier properties only with the coating layer. That is, there is a possibility that defects such as pinholes, cracks, grain boundaries, etc. may occur in the vapor deposition layer, thereby deteriorating the gas barrier properties, and the gas barrier organic-inorganic coating layer compensates for these defects of the vapor deposition layer and provides a gas barrier performance itself can be enhanced.

As a monomer used in polymerization of the newly polymerized acrylic polymer, at least one monomer selected from alkyl (meth)acrylate monomers having C1-C15 carbon atoms in the alkyl group is derived from an acrylate unit or a methacrylate unit, and polymerization reactivity In terms of the (meth)acrylate monomer, it is preferable that the alkyl group has 1 to 15 carbon atoms. Specific examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, iso-butyl acrylate, n-butyl acrylate, and the like. , and these monomers may be used in combination of two or more.

In the present invention, from the viewpoint of water resistance, methyl methacrylate is preferably included in an amount of at least 30 parts by weight or more among the alkyl (meth) acrylate monomers. More preferably, methyl methacrylate is included in an amount of 70 parts by weight or less among the alkyl (meth) acrylate monomers.

Water resistance is generally obtained by crosslinking polymer molecules, but gas barrier property is a property of preventing the introduction or diffusion of relatively small molecules such as oxygen. It is a characteristic that must be realized. For example, a three-dimensionally crosslinkable polymer such as an epoxy resin or a phenol resin has water resistance but does not have a gas barrier property.

Methyl methacrylate is used to impart hardness and function to the polymer while forming a copolymer with acrylic ester monomers. In the present invention, methyl methacrylate is copolymerized with methyl methacrylate to synthesize a polymer having gas barrier properties and water resistance at the same time. The optimal polymer was synthesized by selecting and controlling its content. Methyl methacrylate can impart water resistance to the polymer by appropriately controlling the functionality of these functional groups without inhibiting or interfering with the functions of the monomer having a hydroxyl group and a carboxyl group.

When the amount of methyl methacrylate is less than 30 parts by weight based on 100 parts by weight of the total monomer, the glass transition temperature (Tg) is low, so that the film hardness is weak and water resistance is lowered. And, when it exceeds 70 parts by weight, the Tg may be high and cracks may occur in the film.

The alkyl (meth) acrylate monomer (a) is mixed with at least one or more monomers (b) selected from monomers containing a hydroxyl group copolymerizable with this monomer.

The copolymerizable monomer including a hydroxyl group means a compound having a hydroxyl group at the terminal while having a double bond capable of vinyl polymerization. More preferably, it is a compound having a hydroxyl group at the terminal as a structural unit derived from a vinyl-based monomer having only one polymerizable carbon-carbon double bond in one molecule.

In the present invention, it is preferably an acrylate-based monomer containing a hydroxyl group. In addition, the acrylate-based monomer containing a hydroxyl group is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-chloropropyl (meth) acrylate, 4 -Hydroxybutyl (meth)acrylate, acyloctyloxy-2-hydroxypropyl (meth)acrylate, methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, propyl α-hydroxymethyl acrylate Even more preferred is a compound selected from the group consisting of lactate and butyl α-hydroxymethylacrylate.

In the present invention, the copolymerizable monomer containing a hydroxyl group acts as a modifier that provides a hydrophilic group or a crosslinking site of the polymer. It also serves to form intramolecular or intermolecular hydrogen bonds.

At least one or more monomers (c) selected from monomers containing a carboxyl group copolymerizable with the alkyl (meth)acrylate monomer (a) are mixed.

The copolymerizable monomer including a carboxyl group means a compound having a carboxyl group at the terminal while having a double bond capable of vinyl polymerization. More preferably, it is a compound having a carboxyl group at the terminal as a structural unit derived from a vinyl-based monomer having only one polymerizable carbon-carbon double bond in one molecule.

The copolymerizable monomer containing a carboxyl group is a compound selected from the group consisting of methacrylic acid, acrylic acid, ethylacrylic acid, butylacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, monomethylmaleic acid and 5-norbornene-2-carboxylic acid It is preferable to be

In the present invention, the copolymerizable monomer containing a carboxyl group acts as a functional group that provides a hydrophilic group or cross-linking of the polymer.

These hydroxyl and carboxyl functional groups combine with hydroxyl groups on the surface of the deposition film to improve adhesion, and fill and reinforce defects such as pinholes, cracks, and grain boundaries in the deposition layer to form a dense structure. Therefore, deterioration of gas barrier performance can be suppressed.

The copolymerization amount of the monomer is, (a) a total of 70 to 90 parts by weight of at least one or more monomers selected from alkyl (meth)acrylate monomers having C1-C15 carbon atoms in the alkyl group, (b) copolymerizable including a hydroxyl group A total of 1 to 10 parts by weight of at least one or more monomers selected from monomers, and (c) 5 to 25 parts by weight of a total of at least one or more monomers selected from copolymerizable monomers containing a carboxyl group.

If the amount of the alkyl (meth) acrylate monomer is 70 to 90 parts by weight, it is preferable in terms of water resistance or gas barrier properties.

If the amount of the copolymerizable monomer containing a hydroxyl group is 1 to 10 parts by weight, it is preferable from the viewpoint of gas barrier properties for blocking oxygen. When the ratio of the hydroxyl group present in the acrylic polymer is high, the gas barrier property of the polymer is improved, but there is a problem in that the water resistance is deteriorated.

If the amount of the copolymerizable monomer containing a carboxyl group is 5 to 25 parts by weight, it is preferable from the viewpoint of adhesion. If the ratio of the carboxyl groups present in the acrylic polymer is high, the viscosity of the polymer increases and the coating property is poor, so that it is difficult to obtain a film having a good appearance.

In addition, 30% or more of the carboxyl groups present in the acrylic polymer obtained after polymerization are present in the form of a salt. According to an embodiment of the present invention, after polymerization of the monomer is partially progressed, aqueous ammonia is added to react the carboxyl groups of acrylic acid and methacrylic acid with ammonium ions to form a salt, thereby imparting water solubility to the polymer. When the salt is formed, it may be in the form of an alkali metal salt such as calcium or sodium and/or an ammonium salt, and the type is not limited.

At this time, if the carboxyl groups present in the acrylic polymer form a salt with less than 30%, sufficient water solubility cannot be achieved, so that the polymer is not dissolved in a solvent. And, when the salt is formed in excess of 90%, there is a problem in the coatability due to by-products generated during salt formation.

When the acrylic polymer containing a functional group of a hydroxyl group and a carboxyl group is heat-treated during the production of the gas barrier film, an intermolecular ester bond is formed and cross-linked to obtain a sufficient cross-linking density. , a molded article having high gas barrier properties capable of maintaining gas barrier properties sufficient to withstand practical use even in a high humidity atmosphere is obtained. Moreover, since the reactivity of a hydroxyl group and a carboxyl group is favorable, it can heat-process at high temperature for a short time, and the molded object excellent in transparency with little coloring etc. by heat processing is obtained.

In addition, a monomer represented by the following formula (1) may be further included during polymerization of the acrylic polymer.

In the above formula,

R ₁ is hydrogen or C1-C4 alkyl;

R ₂ is C1-C4 alkyl.

It is preferable that the monomer represented by Formula 1 is glycidyl methacrylate or glycidyl acrylate.

In addition, 0.1 to 5 parts by weight of the monomer represented by Formula 1 may be additionally included based on 100 parts by weight of the total monomer during polymerization of the acrylic polymer.

By including the reactive functional group included in Formula 1 in the acrylic polymer, it is crosslinked with other components (eg, silica nanoparticle dispersion and additives) in the coating composition to impart heat resistance, or adhesion with a gas barrier deposition layer containing an inorganic compound can increase

The acrylic polymer of the present invention is obtained by copolymerizing a C1-C15 alkyl (meth)acrylate monomer (a), a copolymerizable monomer containing a hydroxyl group (b), and a copolymerizable monomer containing a carboxyl group (c). My crosslinking reaction also occurs.

In the acrylic polymer of the present invention, a novel copolymer is synthesized in which a crosslinking component/non-crosslinked hard component/crosslinked component/non-crosslinked hard component is crosslinked and a reactive functional group in the polymer is present by polymerization of a monomer. The acrylic polymer synthesized in this way also has excellent adhesion to the substrate, so that it can have excellent adhesion without a separate adhesive or anchor coating agent.

The prepared acrylic polymer has a weight average molecular weight (Mw _A ) of 100,000 or more and 500,000 or less, and preferably 100,000 or more and 300,000 or less. When the weight average molecular weight is more than 500,000, not only gas barrier properties are insufficient, but also the viscosity is high, so the bubble problem and leveling properties are insufficient during coating.

Moreover, it is preferable that the glass transition temperature of an acryl-type polymer is 20 degreeC or more. More preferably, it is preferable that it is 20 degreeC or more and 60 degrees C or less. When the glass transition temperature is within this range, deformation such as thermal shrinkage of the resulting film is less likely to occur. In addition, a glass transition temperature is a midpoint glass transition temperature measured based on JISK7121. Specifically, the sample was heated to 230°C, then cooled to room temperature, and thereafter, the DSC curve was measured under the conditions of increasing the temperature from room temperature to 230°C at 10°C/min. The midpoint glass transition temperature obtained from the DSC curve measured at the time of the second temperature increase was determined.

The acrylic polymer used in the present invention can be prepared by a known polymerization method. Each characteristic of the above-described acrylic polymer can be realized by adjusting polymerization conditions such as polymerization temperature, polymerization time, and type and amount of polymerization initiator. As a polymerization reaction form used for the preparation of a methyl methacrylate-based polymer, for example, a radical polymerization method may be mentioned.

In the radical polymerization method, polymerization methods, such as the suspension polymerization method, the block polymerization method, the solution polymerization method, the emulsion polymerization method, are employable. Among these, the solution polymerization method is preferable from a viewpoint of productivity.

The polymerization reaction is initiated by a polymerization initiator. The polymerization initiator used for radical polymerization will not be specifically limited if it generate|occur|produces a reactive radical. Such a polymerization initiator has a one-hour half-life temperature of preferably 60 to 140°C, more preferably 80 to 120°C.

Examples of the polymerization initiator used in radical polymerization include t-hexylperoxyisopropylmonocarbonate, t-hexylperoxy2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, t-butylperoxypivalate, t-hexylperoxypivalate, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, 1,1,3,3 -Tetramethylbutylperoxyneodecanoate, 1,1-bis(t-hexylperoxy)cyclohexane, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, 2,2 '-azobis(2-methylpropionitrile), 2,2'-azobis(2-methylbutyronitrile), dimethyl 2,2'-azobis(2-methylpropionate), etc. are mentioned. . Especially, benzoyl peroxide is preferable. These polymerization initiators can be used individually by 1 type or in combination of 2 or more type. The addition amount, addition method, etc. of a polymerization initiator may just set suitably according to the objective, and are not specifically limited.

The solvent used for the solution polymerization method is not particularly limited as long as it can dissolve the monomer and the polymer and does not deactivate radicals. It is preferable to use alcohols as such a solvent. More preferably, ethyl alcohol is preferable. These solvents can be used individually by 1 type or in combination of 2 or more type. The amount of the solvent to be used can be appropriately set from the viewpoints of the viscosity and productivity of the reaction solution.

The temperature at the time of the polymerization reaction can be appropriately set depending on the reaction form or from the viewpoints of the polymerization reaction rate, the viscosity of the polymerization reaction liquid, suppression of the formation of by-products, and the like. In radical polymerization, when performing solution polymerization, the temperature at the time of a polymerization reaction becomes like this. Preferably it is 50-150 degreeC, More preferably, it is 60-100 degreeC.

As for the monomer input method, it is possible to use either batch input or continuous input, respectively, or a combination of both.

The polymerization reaction for producing the acrylic polymer can be carried out by a batch reaction or a continuous flow reaction. In the present invention, it is produced by a batch reaction, for example, a polymerization reaction raw material (a mixture containing a monomer, a polymerization initiator, etc.) is prepared under a nitrogen atmosphere, etc., all of it is injected into a reactor, the reaction is performed for a predetermined time, take out

After completion of polymerization, volatile components such as unreacted monomers are removed if necessary. The removal method is not particularly limited.

The acrylic polymer used in the present invention may be used by mixing one or more acrylic polymers polymerized by the polymerization method described above.

The dispersion of silica nanoparticles of the present invention includes an aqueous dispersion and an organic solvent dispersion. The silica particle size preferably has an average particle diameter of 1 nm to 50 nm, and more preferably has an average particle diameter of 5 nm to 20 nm at the time of crack control of the gas barrier film.

The average particle size can be determined using transmission electron microscopy. The nanosilica described in this disclosure may be spherical or non-spherical.

The surface of silica nanoparticles has a large number of reactive hydroxy groups (silanol groups), similar to ordinary silica, and by chemical reaction, surface modification and intermolecular crosslinking are possible.

The silica nanoparticle dispersion is preferably contained in an amount of 5 to 20 parts by weight based on 90 parts by weight of the acrylic polymer from the viewpoint of having excellent oxygen gas barrier properties even under high humidity conditions, and more preferably 10 parts by weight.

When the content of the silica nanoparticle dispersion is less than 5 parts by weight, the gas barrier property tends to decrease, and when the content is larger than 20 parts by weight, the coatability when the gas barrier film is coated is inferior or the flexibility is lowered and the haze tends to increase.

In the present invention, the solvent uniformly dissolves and disperses the acrylic polymer and silica nanoparticles on a water-soluble basis, and it is preferable to use an aqueous solvent or a water/organic solvent mixture. Specific examples of the solvent include water, methanol, ethanol, isopropyl alcohol, 1-propol, 2-propol, and mixtures thereof.

Since silica nanoparticles are easy to aggregate with each other, it is preferable to adjust the pH to less than 5 in order to be dispersed in a solvent.

When the gas barrier coating composition of the present invention is subjected to heat treatment when manufacturing the gas barrier film, the silica nanoparticles are bonded to the adjacent silica nanoparticles to form a three-dimensional network structure. In addition, while these nanoparticles are positioned between the acrylic polymer, a polymer polymer and an organic-inorganic hybrid coating film are formed.

In particular, the silanol group on the surface of the silica nanoparticles and the hydroxyl group and carboxyl group, which are functional groups of the acrylic polymer, are crosslinked to form a more dense and homogeneous three-dimensional network structure.

Through this, the gas barrier property is not deteriorated even under high humidity conditions, and at the same time, the adhesion between the deposition layer and the coating layer is not reduced.

The gas barrier coating composition of the present invention may further include a silane coupling agent. Further, the silane coupling agent is preferably an epoxy-based silane coupling agent. Epoxy silane coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane and 2-(3,4-epoxycyclohexyl)- It may be at least one selected from the group consisting of ethyltrimethoxysilane.

The silane coupling agent is preferably added in an amount of 0.1 to 5.0 parts by weight based on 90 parts by weight of the acrylic polymer.

Through the addition of the silane coupling agent, it is possible to further improve the adsorption force with the substrate lowered by the addition of the silica nanoparticle dispersion.

The method for forming the gas barrier organic-inorganic coating layer in the present invention is not particularly limited, and depending on the plastic film, for example, printing methods such as offset printing, gravure printing, silk screen printing, roll coating method, dip A coating solution is coated using a coating method, bar coating method, die coating method, knife edge coating method, gravure coating method, kiss coating method, spin coating method, etc. or a combination thereof, and thermal curing, ultraviolet curing, infrared curing , can be manufactured by hardening by induction heat treatment method.

The thickness of the organic-inorganic coating layer provided on the deposition layer is preferably 0.01 µm to 2 µm, more preferably 0.1 µm to 1.5 µm. If the thickness of the coating layer is less than 0.01 μm, gas barrier performance may not be expressed. In addition, there is also a problem in that the coating drying conditions are high temperature and required for a long time, which increases the manufacturing cost.

In the present invention, the gas barrier organic-inorganic coating layer is formed by drying by heating at 50 to 160°C. Here, the drying is the main purpose of removing the solvent in the coating composition, and the coating composition of the present invention can be dried at a low temperature in a short time. Since the drying temperature requires the temperature at which water evaporates, 70 degreeC or more and 150 degrees C or less are preferable, and 80 degrees C or more and 140 degrees C or less are more preferable. The drying time is determined by the composition of the acrylic polymer of the present invention, and in the above temperature range, it can be dried in a short time from 5 seconds to 10 minutes, and further, to 1 minute or less.

In addition, the coating layer may consist of two or more layers having the same or different composition, and by sharing the intended action, a gas barrier film having various properties can be produced.

[Gas barrier laminate]

The gas barrier laminate of the present invention comprises the previously described gas barrier film; a sealant film installed on the back of the plastic film of the gas barrier film; and a printing film installed on the back surface of the organic-inorganic coating layer of the gas barrier film.

In the gas barrier laminate of the present invention, a printing film as a surface protection layer, a gas barrier film, and a sealant film as a heat sealing layer are laminated in this order.

As shown in FIG. 2, for example, on a plastic film 10 dry laminated through a sealant layer 50 and an adhesive layer (not shown), an aluminum oxide deposition layer 20, an organic-inorganic coating layer 30, It has a configuration 200 in which the dry-laminated printing film 40 is sequentially laminated through an adhesive layer (not shown).

Alternatively, as shown in FIG. 3, for example, on a polyamide-based plastic film 10 extruded and laminated with a sealant layer 50, a low-density polyethylene adhesive layer 70, an aluminum oxide deposition layer 20, an organic-inorganic The coating layer 30, the low-density polyethylene adhesive layer 60, and the extrusion-laminated printing film 40 have a configuration 300 in which they are sequentially stacked.

The printing film is formed as a printing layer, and characters or designs are formed in order to be practically used as a packaging material. There is no particular limitation as long as characteristics such as chemical resistance, mechanical strength (elasticity of the film, wear from the outside, puncture strength), heat resistance, and weather resistance are taken into consideration depending on the application. In the embodiment of the present invention, a polyester-based film or a polyamide-based film is used in terms of mechanical strength and thermal stability to serve as an intermediate layer formed to increase the strength of bag breaking during boiling and retort sterilization. Although an unstretched film may be sufficient, it is excellent in mechanical characteristics and uniformity of thickness that it is normally extended|stretched (uniaxial or biaxial), and a biaxially stretched film is more preferable. Although there is no restriction|limiting in particular in thickness, If it is a polyethylene terephthalate film, about 6 micrometers - about 30 micrometers, and if it is a nylon film, about 10 micrometers - about 30 micrometers is practical. What laminated|stacked multiple sheets of these printing films according to request|requirement may be used as a surface protective layer.

The sealant film is formed as a sealing layer and functions to prevent wrinkles and maintain shape. Depending on the application, there is no particular limitation as long as characteristics such as chemical resistance, mechanical strength (elasticity of film, external abrasion, puncture strength), heat resistance, and weather resistance are taken into consideration, but polyethylene-based film, polypropylene-based film, ethylene-vinyl acetate Films such as a copolymer film, an ethylene-methacrylic acid copolymer film, an ethylene-methacrylic acid ester copolymer film, an ethylene-acrylic acid copolymer film, an ethylene-acrylic acid ester copolymer, and metal crosslinked products thereof can be used. Among them, it is preferable to use a polyethylene-based film or a polypropylene-based film. For example, a polyethylene film, a polypropylene film, etc. are used. Even more preferably, a polyethylene film is practical, in particular a linear low-density polyethylene film (LLDPE) is particularly preferred. Although there is no restriction|limiting in particular as for thickness, 30 micrometers - 300 micrometers, More preferably, 30 micrometers - 80 micrometers, if it is a polyethylene film, is practical. Moreover, if it is a polypropylene film, it is 20 micrometers - 200 micrometers, More preferably, it is 20 micrometers - 70 micrometers, and a precision is practical.

In the gas barrier laminate with reinforced heat resistance of the present invention, the printing film, the gas barrier film, and the sealant film are laminated with an adhesive for dry lamination, and the oxygen permeability is maintained at 0.7cc/m ² ·day or less even after lamination. do it with

The adhesive for dry lamination is not particularly limited, but is preferably a urethane-based adhesive. For example, a two-component curing type urethane-based adhesive or the like is used.

According to another aspect of the present invention, the printing film, the gas barrier film, and the sealant film are laminated by extruding a polyethylene ^- based resin at a high temperature of 280 to 320° C. Disclosed is a gas barrier laminate with reinforced heat resistance.

[Method for manufacturing gas barrier laminate with reinforced heat resistance]

The manufacturing method of the gas barrier laminate of the present invention may employ a dry lamination method using an adhesive for dry lamination, a non-solvent dry lamination method in which lamination is performed using a solvent-free adhesive, an extrusion lamination method, etc., but is not particularly limited. .

In particular, in the manufacturing method of the present invention, a dry lamination method in which an adhesive for dry lamination is applied over a certain thickness and dried at 70 to 90° C., and then the laminated laminate is aged for 3 to 7 days at 40 to 50° C. A gas barrier laminate with stronger heat resistance can be produced by using the extrusion lamination method that pressurizes a printing film, a gas barrier film, and a sealant film while simultaneously forming an adhesive layer by melt-extruding it at a high temperature of 280 to 320 ° C. have.

First, the method of manufacturing a gas barrier laminate of the present invention according to the dry lamination method comprises: forming a gas barrier deposition layer containing an inorganic compound directly on a polyamide-based plastic film or through an anchor coat layer; preparing a gas barrier coating composition as described above comprising an acrylic polymer and a silica nanoparticle dispersion; preparing the gas barrier film described above by applying the coating composition directly on the gas barrier deposition layer or through an anchor coat layer to form an organic-inorganic coating layer; forming an adhesive layer in a dry adhesive state by applying a dry laminate adhesive to the back surface of the plastic film and/or the back surface of the organic-inorganic coating layer and evaporating to dryness at 70 to 90° C.; Laminating the sealant film by pressure bonding to the adhesive layer of the plastic film, and pressure bonding the printing film to the adhesive layer of the organic-inorganic coating layer; It includes the step of aging the laminated laminate at 40 ~ 50 ℃ 3 ~ 7 days.

An adhesive layer may be formed at the same time on the plastic back side of the gas barrier film and the organic-inorganic coating layer on the back side. After forming, it is done by a lamination method in which a dissimilar film is pressed and adhered.

According to the manufacturing process and equipment of the gas barrier laminate by the dry lamination process of FIG. 4, the water-type or organic solvent-type dry laminate adhesive is applied to the back side of the polyamide-based plastic film or the organic-inorganic coating layer with a certain thickness by the gravure roller. An adhesive layer is formed that is uniformly coated and evaporated to dryness at 70 ~ 90℃ inside the drying chamber, and is heated to 50 ~ 90℃ by bonding another substrate, a printing film or a sealant film, to this adhesive layer. It is laminated by pressure bonding between the roll and the rubber roll, passed through a cooling roll, and then wound up. This laminated laminate is aged at 40 to 50° C. for 3 to 7 days to further enhance heat resistance. When the aging step is passed, the flow of the adhesive is improved and the leveling of the film is improved, so that bubbles, coating stains, cell marks, etc. are eliminated, so that transparency is improved. In addition, the area in which the adhesive is in contact with the film increases, the internal distortion is reduced due to the movement of the adhesive molecules, and the adhesive strength is strengthened due to the completion of the adhesive crosslinking reaction, etc., so that the heat resistance is improved. Furthermore, the organic-inorganic coating layer of the present invention is cured again, so that the crosslinking reaction proceeds further to further improve heat resistance.

According to another aspect of the present invention, a method for manufacturing a gas barrier laminate according to an extrusion lamination method includes: forming a gas barrier deposition layer containing an inorganic compound directly on a plastic film or through an anchor coat layer; preparing a composition described above comprising an acrylic polymer, and a silica nanoparticle dispersion; preparing the gas barrier film described above by applying the composition directly on the gas barrier deposition layer or through an anchor coat layer to form an organic-inorganic coating layer; Putting a polyethylene-based resin into an extruder and melt-extruding it at a high temperature of 280 to 320° C. to form a first adhesive layer on one surface of the printing film, while integrally bonding the gas barrier film to the back surface of the first adhesive layer and laminating; A polyethylene-based resin is put into an extruder on the back surface of the gas barrier film and melt-extruded at a high temperature of 280 to 320° C. to form a second adhesive layer, and at the same time, laminating a sealant film on the back surface of the second adhesive layer.

According to the manufacturing process and equipment of the gas barrier laminate by the extrusion lamination process of FIG. 5, polyethylene melt-extruded at a high temperature of 280 to 320° C. is coated on the printing film (substrate 1) while forming the first adhesive layer and the first adhesive layer While allowing the gas barrier film (substrate 2) to be positioned on the back surface of the After that, polyethylene, melt-extruded at a high temperature of 280 to 320 ° C after undergoing an intermediate lamination process, is coated on the back surface of the gas barrier film (base 2) to form a second adhesive layer and at the same time, a sealant film on the back surface of the second adhesive layer (base 3) While allowing this to be positioned, it is passed through the compression roller and laminated integrally.

At this time, while forming the second adhesive layer on the back surface of the gas barrier film, melt-extruding the raw material resin of the sealant film on the back surface of the second adhesive layer to form the sealant film while passing it through a compression roller to integrally laminate it to improve heat resistance It is more preferable to do

The gas barrier laminate manufactured using the extrusion lamination method of the present invention does not deteriorate gas barrier properties due to high temperature and the organic-inorganic coating layer is cured again, so that it is possible to manufacture a laminate with more enhanced durability and heat resistance. By using the bar, it is possible to provide a packaging material with more reinforced durability and heat resistance.

[Instant food packaging material for gas barrier boiling and retort]

In addition to the structure of the above laminate, it is possible to provide a ready-to-eat food packaging material for boil and retort including the gas barrier film of the present invention. A relief layer, such as a stretched nylon film, a stretched polyester film, and a stretched polypropylene film, can be further provided between a gas barrier film and a sealant layer, for example. By providing such a layer, it becomes possible to further improve pinhole resistance, impact resistance, and heat resistance further.

That is, it is possible to laminate a plurality of films through a printing layer, a sealant layer, and an adhesive on the gas barrier film if necessary. In addition, it is also possible to laminate a plurality of films through a printing layer, a sealant layer, and an adhesive on the opposite side of the plastic film, which is the base material of the gas barrier film.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are for illustration of the present invention, and the scope of the present invention is not intended to be limited by the following examples.

Example

<Preparation Example 1: Preparation of acrylic polymer 1>

Prepare a 1 liter round four-necked flask. Set the cooler and nitrogen line. The monomers are 45.0 parts by weight of methyl methacrylate, 38.0 parts by weight of ethyl acrylate, 2.0 parts by weight of 2-hydroxyethyl methacrylate, 10.0 parts by weight of methacrylic acid, 5.0 parts by weight of acrylic acid, and glycidyl methacrylate relative to the total monomers. 0.5 parts by weight and 5.0 parts by weight of ethyl alcohol were put into the flask, purged with nitrogen to remove oxygen for 30 minutes, and the temperature was raised. As an initiator, 0.3 parts by weight of benzoyl peroxide (75%) was added to the flask at 50°C. When the reaction starts at 70°C to 72°C, the reaction temperature is maintained for 5 hours. At 60°C, 1.0 parts by weight of aqueous ammonia (25%) and 3.0 parts by weight of water are mixed and added dropwise to the reaction part for 10 minutes. After completion of dripping, hold at 60°C for 30 minutes. When the reaction is complete, it is cooled down to 50°C or less. 28.0 parts by weight of isopropyl alcohol and 52.7 parts by weight of deionized water were added to terminate the reaction. An acrylic polymer 1 having a Tg value of +45° C., a solid content of 10.0%, and a viscosity of 100 cps or less was prepared.

<Preparation Example 2: Preparation of acrylic polymer 2>

Prepare a 1 liter round four-necked flask. Set the cooler and nitrogen line. The monomers are 45.0 parts by weight of methyl methacrylate, 38.0 parts by weight of ethyl acrylate, 2.0 parts by weight of 2-hydroxyethyl acrylate, 10.0 parts by weight of methacrylic acid, 5.0 parts by weight of acrylic acid, 0.5 parts by weight of glycidyl methacrylate relative to the total monomers Into a flask by weight, 5.0 parts by weight of ethyl alcohol, purged with nitrogen for oxygen removal for 30 minutes, and the temperature is raised. As an initiator, 0.3 parts by weight of benzoyl peroxide (75%) was added to the flask at 50°C. When the reaction starts at 70°C to 72°C, the reaction temperature is maintained for 5 hours. At 60°C, 1.0 parts by weight of aqueous ammonia (25%) and 3.0 parts by weight of water are mixed and added dropwise to the reaction part for 10 minutes. After completion of dripping, hold at 60°C for 30 minutes. When the reaction is complete, it is cooled down to 50°C or less. 28.0 parts by weight of isopropyl alcohol and 52.7 parts by weight of deionized water were added to terminate the reaction. An acrylic polymer 2 having a Tg value of +45° C., a solid content of 10.0%, and a viscosity of 100 cps or less was prepared.

<Preparation Example 3: Preparation of acrylic polymer 3>

Prepare a 1 liter round four-necked flask. Set the cooler and nitrogen line. The monomer is 45.0 parts by weight of methyl methacrylate, 38.0 parts by weight of ethyl acrylate, 1.0 parts by weight of 2-hydroxyethyl methacrylate, 1.0 parts by weight of 2-hydroxyethyl acrylate, 5.0 parts by weight of methacrylic acid, 10.0 parts by weight of acrylic acid, 0.5 parts by weight of glycidyl methacrylate, and 5.0 parts by weight of ethyl alcohol were put in a flask, purged with nitrogen to remove oxygen for 30 minutes, and the temperature was raised. As an initiator, 0.3 parts by weight of benzoyl peroxide (75%) was added to the flask at 50°C. When the reaction starts at 70°C to 72°C, the reaction temperature is maintained for 5 hours. At 60°C, 1.0 parts by weight of aqueous ammonia (25%) and 3.0 parts by weight of water are mixed and added dropwise to the reaction part for 10 minutes. After completion of dripping, hold at 60°C for 30 minutes. When the reaction is complete, it is cooled down to 50°C or less. 28.0 parts by weight of isopropyl alcohol and 52.7 parts by weight of deionized water were added to terminate the reaction. An acrylic polymer 3 having a Tg value of +44° C., a solid content of 10.0%, and a viscosity of 100 cps or less was prepared.

<Preparation Example 4: Preparation of acrylic polymer 4>

Prepare a 1 liter round four-necked flask. Set the cooler and nitrogen line. The monomer is 45.0 parts by weight of methyl methacrylate, 38.0 parts by weight of ethyl acrylate, 2.0 parts by weight of 2-hydroxyethyl methacrylate, 5.0 parts by weight of methacrylic acid, 10.0 parts by weight of acrylic acid, 10.0 parts by weight of glycidyl methacrylate relative to the total monomers 0.5 parts by weight and 5.0 parts by weight of ethyl alcohol were put into the flask, purged with nitrogen to remove oxygen for 30 minutes, and the temperature was raised. As an initiator, 0.3 parts by weight of benzoyl peroxide (75%) was added to the flask at 50°C. When the reaction starts at 70°C to 72°C, the reaction temperature is maintained for 5 hours. At 60°C, 1.0 parts by weight of aqueous ammonia (25%) and 3.0 parts by weight of water are mixed and added dropwise to the reaction part for 10 minutes. After completion of dripping, hold at 60°C for 30 minutes. When the reaction is complete, it is cooled to 50 °C or less. 28.0 parts by weight of isopropyl alcohol and 52.7 parts by weight of deionized water were added to terminate the reaction. An acrylic polymer 4 having a Tg value of +43° C., a solid content of 10.0%, and a viscosity of 100 cps or less was prepared.

<Preparation Example 5: Preparation of acrylic polymer 5>

Prepare a 1 liter round four-necked flask. Set the cooler and nitrogen line. The monomer is 45.0 parts by weight of methyl methacrylate, 42.0 parts by weight of ethyl acrylate, 0.5 parts by weight of 2-hydroxyethyl methacrylate, 0.5 parts by weight of 2-hydroxyethyl acrylate, 5.0 parts by weight of methacrylic acid, 2.5 parts by weight of acrylic acid, 0.5 parts by weight of glycidyl methacrylate, and 5.0 parts by weight of ethyl alcohol were put into a flask, purged with nitrogen for removing oxygen for 30 minutes, and the temperature was raised. As an initiator, 0.3 parts by weight of benzoyl peroxide (75%) was added to the flask at 50°C. When the reaction starts at 70°C to 72°C, the reaction temperature is maintained for 5 hours. At 60°C, 1.0 parts by weight of aqueous ammonia (25%) and 3.0 parts by weight of water are mixed and added dropwise to the reaction part for 10 minutes. After completion of dripping, hold at 60°C for 30 minutes. When the reaction is complete, it is cooled down to 50°C or less. 28.0 parts by weight of isopropyl alcohol and 52.7 parts by weight of deionized water were added to terminate the reaction. An acrylic polymer 5 having a Tg value of +39° C., a solid content of 10.0%, and a viscosity of 100 cps or less was prepared.

<Preparation Example 6: Preparation of acrylic polymer 6>

Prepare a 1 liter round four-necked flask. Set the cooler and nitrogen line. The monomers are 15.0 parts by weight of methyl methacrylate, 67.5 parts by weight of ethyl acrylate, 2.0 parts by weight of 2-hydroxyethyl methacrylate, 10.0 parts by weight of methacrylic acid, 5.0 parts by weight of acrylic acid, and glycidyl methacrylate compared to the total monomers. 0.5 parts by weight and 5.0 parts by weight of ethyl alcohol were put into the flask, purged with nitrogen to remove oxygen for 30 minutes, and the temperature was raised. As an initiator, 0.3 parts by weight of benzoyl peroxide (75%) was added to the flask at 50°C. When the reaction starts at 70°C to 72°C, the reaction temperature is maintained for 5 hours. At 60°C, 1.0 parts by weight of aqueous ammonia (25%) and 3.0 parts by weight of water are mixed and added dropwise to the reaction part for 10 minutes. After completion of dripping, hold at 60°C for 30 minutes. When the reaction is complete, it is cooled to 50 °C or less. 28.0 parts by weight of isopropyl alcohol and 52.7 parts by weight of deionized water were added to terminate the reaction. An acrylic polymer 6 having a Tg value of +9° C., a solid content of 10.0%, and a viscosity of 100 cps or less was prepared.

<Preparation Example 7: Preparation of acrylic polymer 7>

Prepare a 1 liter round four-necked flask. Set the cooler and nitrogen line. The monomers are 70.0 parts by weight of methyl methacrylate, 12.5 parts by weight of ethyl acrylate, 2.0 parts by weight of 2-hydroxyethyl methacrylate, 10.0 parts by weight of methacrylic acid, 5.0 parts by weight of acrylic acid, and glycidyl methacrylate compared to the total monomers. 0.5 parts by weight and 5.0 parts by weight of ethyl alcohol were put into the flask, purged with nitrogen to remove oxygen for 30 minutes, and the temperature was raised. As an initiator, 0.3 parts by weight of benzoyl peroxide (75%) was added to the flask at 50°C. When the reaction starts at 70°C to 72°C, the reaction temperature is maintained for 5 hours. At 60°C, 1.0 parts by weight of aqueous ammonia (25%) and 3.0 parts by weight of water are mixed and added dropwise to the reaction part for 10 minutes. After completion of dripping, hold at 60°C for 30 minutes. When the reaction is complete, it is cooled down to 50°C or less. 28.0 parts by weight of isopropyl alcohol and 52.7 parts by weight of deionized water were added to terminate the reaction. An acrylic polymer 7 having a Tg value of +83° C., a solid content of 10.0%, and a viscosity of 100 cps or less was prepared.

[Production of gas barrier film]

<Reference Example 1>

Biaxially stretched nylon with plasma treatment on one side having a thickness of 15 μm is used as a base material, and aluminum is used as an evaporation source on the plasma-treated side, and is heated and deposited by a heating method by a thermal evaporation machine, and the pressure is 1.2 × 10 ⁻ It adjusted so that it might become a predetermined|prescribed film composition, introduce|transducing oxygen gas so that it might become ² Pa, and the aluminum oxide vapor deposition layer with a film thickness of 30 nm was formed.

<Example 1>

(1) Preparation of gas barrier deposition layer

The aluminum oxide deposition layer of Reference Example 1 was used.

(2) Preparation of coating composition

90.0 parts by weight of the acrylic polymer 1 prepared in Preparation Example 1 is added, and 10.0 parts by weight of the nano-silica dispersion (solid content 30.0%, aqueous dispersion, average particle diameter 10 nm) is added and mixed for 3 hours. After confirming that the dispersion was completed, 0.1 parts by weight of a leveling agent, 0.1 parts by weight of a silane coupling agent, and 0.1 parts by weight of an antifoaming agent were sequentially added and mixed for 2 hours to prepare a gas barrier coating composition.

(3) Preparation of gas barrier film

To the aluminum oxide deposited layer, the gas barrier coating composition prepared above is applied to the upper surface of the deposited layer obtained by using a bar coating method, and cured by heating at 140° C. for 60 seconds, thereby providing a gas barrier having a film thickness of about 0.4 μm. The coating layer was formed, and the gas barrier film as shown in FIG. 1 was manufactured.

<Example 2>

A gas barrier deposition layer was prepared in the same manner as in Example 1. A gas barrier coating composition was prepared in the same manner as in Example 1 except that the acrylic polymer 2 prepared in Preparation Example 2 was used, and a gas barrier film was prepared in the same manner as in Example 1 using the same.

<Example 3>

A gas barrier deposition layer was prepared in the same manner as in Example 1. A gas barrier coating composition was prepared in the same manner as in Example 1 except that the acrylic polymer 3 prepared in Preparation Example 3 was used, and a gas barrier film was prepared in the same manner as in Example 1 using the same.

<Example 4>

A gas barrier deposition layer was prepared in the same manner as in Example 1. A gas barrier coating composition was prepared in the same manner as in Example 1 except that the acrylic polymer 4 prepared in Preparation Example 4 was used, and a gas barrier film was prepared in the same manner as in Example 1 using the same.

<Example 5>

A gas barrier deposition layer was prepared in the same manner as in Example 1. A gas barrier coating composition was prepared in the same manner as in Example 1 except that the acrylic polymer 5 prepared in Preparation Example 5 was used, and a gas barrier film was prepared in the same manner as in Example 1 using the same.

<Example 6>

A gas barrier deposition layer was prepared in the same manner as in Example 1. 90.0 parts by weight of the acrylic polymer 1 prepared in Preparation Example 1 is added, and 10.0 parts by weight of the nano-silica dispersion (solid content 30.0%, aqueous dispersion, average particle diameter 10 nm) is added and mixed for 3 hours. After confirming that the dispersion was completed, 0.1 parts by weight of a leveling agent, 0.5 parts by weight of a silane coupling agent, and 0.1 parts by weight of an antifoaming agent were sequentially added and mixed for 2 hours to prepare a gas barrier coating composition. Using this, a gas barrier film was prepared in the same manner as in Example 1.

<Comparative Example 1>

A gas barrier deposition layer was prepared in the same manner as in Example 1. A gas barrier coating composition was prepared in the same manner as in Example 1 except that the acrylic polymer 6 prepared in Preparation Example 6 was used, and a gas barrier film was prepared in the same manner as in Example 1 using the same.

<Comparative Example 2>

A gas barrier deposition layer was prepared in the same manner as in Example 1. A gas barrier coating composition was prepared in the same manner as in Example 1 except that the acrylic polymer 7 prepared in Preparation Example 7 was used, and a gas barrier film was prepared in the same manner as in Example 1 using the same.

<Comparative Example 3>

A gas barrier deposition layer was prepared in the same manner as in Example 1. 90.0 parts by weight of the acrylic polymer 1 prepared in Preparation Example 1 is added, and 3.0 parts by weight of the nano-silica dispersion (solid content 30.0%, aqueous dispersion, average particle diameter 10 nm) is added and mixed for 3 hours. After confirming that the dispersion was completed, 0.1 parts by weight of a leveling agent, 0.1 parts by weight of a silane coupling agent, and 0.1 parts by weight of an antifoaming agent were sequentially added and mixed for 2 hours to prepare a gas barrier coating composition. Using this, a gas barrier film was prepared in the same manner as in Example 1.

<Comparative Example 4>

A gas barrier deposition layer was prepared in the same manner as in Example 1. 90.0 parts by weight of the acrylic polymer 1 prepared in Preparation Example 1 is added, and 30.0 parts by weight of the nano-silica dispersion (solid content 30.0%, aqueous dispersion, average particle diameter 10 nm) is added and mixed for 3 hours. After confirming that the dispersion was completed, 0.1 parts by weight of a leveling agent, 0.1 parts by weight of a silane coupling agent, and 0.1 parts by weight of an antifoaming agent were sequentially added and mixed for 2 hours to prepare a gas barrier coating composition. Using this, a gas barrier film was prepared in the same manner as in Example 1.

Table 1 shows the contents of Examples and Comparative Examples.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 plastic film NY NY NY NY NY NY NY NY NY NY deposited layer AlOx AlOx AlOx AlOx AlOx AlOx AlOx AlOx AlOx AlOx Acrylic polymer 1 90 90 90 90 Acrylic polymer 2 90 Acrylic polymer 3 90 Acrylic polymer 4 90 Acrylic polymer 5 90 Acrylic polymer 6 90 Acrylic polymer 7 90 Nano Silica Dispersion 10 10 10 10 10 10 10 10 3 30 leveling agent 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Silane coupling agent 0.1 0.1 0.1 0.1 0.1 0.5 0.1 0.1 0.1 0.1 antifoam 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Solid content (%) ^※1 10 10 10 10 10 10 10 10 10 10 Viscosity (cps) ^※2 below 10 below 10 below 10 below 10 below 10 below 10 below 10 below 10 below 10 below 10

_{※1 Solid content measurement method: Kett FD-660 (Measurement conditions: 140℃, 30 minutes)}

_{※2 Viscosity measurement method: Viscometer Brookfield LVDV2T (Spindle #61, 60rpm)}

[Production of gas barrier laminate]

<Example 7>

Using the equipment applied to the dry lamination process as shown in FIG. 4, the non-stretched polypropylene (sealant layer) having a thickness of 30 μm was coated on the back side of the biaxially stretched nylon of the gas barrier film obtained in Example 1 by a laminator. Laminated using a urethane-based two-part adhesive (Gangnam Chemical KUB385/CL100), and 15 μm thick stretched nylon (printing layer) on the back of the gas barrier coating layer, and a polyurethane-based two-part adhesive (Gangnam Chemical KUB385/CL100) It laminated and aged at 50 degreeC for 5 days, and the laminated body as shown in FIG. 2 was produced.

<Example 8>

A polyurethane-based low-density polyethylene (sealant layer) having a thickness of 30 μm was applied by a laminator to the back of the biaxially stretched nylon of the gas barrier film obtained in Example 6 using the equipment applied to the dry lamination process as shown in FIG. 4 . Laminated using a two-component adhesive (Gangnam Chemical KUB385/CL100), and stretched nylon (printing layer) with a thickness of 15 μm on the back of the gas barrier coating layer, and a polyurethane-based two-part adhesive (Gangnam Chemical KUB385/CL100) It laminated and aged at 50 degreeC for 5 days, and the laminated body as shown in FIG. 2 was produced.

<Example 9>

A polyethylene terephthalate (printed layer) having a thickness of 12 μm is prepared in lamination station 1 using the equipment applied to the extrusion lamination process as shown in FIG. 5, and the temperature of the extruder barrel is 300° C. and the die temperature is 300 ℃, and the extrusion rate is adjusted to 150kg/hr to melt the low-density polyethylene to form the first adhesive layer, and at the same time to laminate with the back surface of the gas barrier coating layer of the gas barrier film obtained in Example 1.

Then, on the back of the biaxially stretched nylon obtained in Example 1 in lamination station 2, the temperature of the extruder barrel is maintained at 300° C., the die temperature is maintained at 300° C., and the extrusion rate is adjusted to 150 kg/hr to melt the low-density polyethylene to melt the second A laminate as shown in FIG. 3 was produced by laminating a linear low-density polyethylene (sealant layer) while forming an adhesive layer.

<Example 10>

A polyethylene terephthalate (printed layer) having a thickness of 12 μm is prepared in lamination station 1 using the equipment applied to the extrusion lamination process as shown in FIG. 5, and the temperature of the extruder barrel is 300° C. and the die temperature is 300 ℃, the extrusion rate is adjusted to 150kg / hr to melt the low-density polyethylene to form the first adhesive layer and at the same time laminated with the back surface of the gas barrier coating layer of the gas barrier film obtained in Example 6.

Then, in lamination station 2, the temperature of the extruder barrel is maintained at 300° C. and the die temperature at 300° C. on the back of the biaxially stretched nylon obtained in Example 6, and the extrusion speed is adjusted to 150 kg/hr to melt the low-density polyethylene to melt the second A laminate as shown in FIG. 3 was produced by laminating a linear low-density polyethylene (sealant layer) while forming an adhesive layer.

<Reference Example 2>

A polyurethane-based two-component type of stretched nylon (printed layer) with a thickness of 25 μm by a laminator on one side of an ethylene-vinyl alcohol film with a thickness of 15 μm using a facility applied to the dry lamination process as shown in FIG. 4 as a conventionally used structure Laminated using an adhesive (Gangnam Chemical KUB385/CL100), and on the opposite side, a linear low-density polyethylene (sealant layer) with a thickness of 30 μm was laminated using a polyurethane-based two-part adhesive (Gangnam Chemical KUB385/CL100) at 40°C. It aged for 3 days to produce a laminated body.

<Comparative Example 5>

A polyethylene terephthalate (printed layer) having a thickness of 12 μm is prepared in lamination station 1 using the equipment applied to the extrusion lamination process as shown in FIG. 5, and the temperature of the extruder barrel is 300° C. and the die temperature is 300 ℃, and the extrusion rate is adjusted to 150 kg/hr to melt the low-density polyethylene to form the first adhesive layer, and at the same time laminate it with one side of an ethylene-vinyl alcohol film with a thickness of 15 μm.

Then, on the back of the ethylene-vinyl alcohol film in lamination station 2, the temperature of the extruder barrel is maintained at 300°C, the die temperature is maintained at 300°C, and the extrusion speed is adjusted to 150kg/hr to melt the low-density polyethylene to form a second adhesive layer. At the same time, a laminate was prepared by laminating linear low-density polyethylene (sealant layer).

<Comparative Example 6>

A non-stretched polypropylene film (sealant layer) having a thickness of 30 μm was applied by a laminator on the back of the biaxially stretched nylon of the gas barrier film obtained in Comparative Example 3 using the equipment applied to the dry lamination process as shown in FIG. 4 . Laminated using a polyurethane-based two-component adhesive (Gangnam Chemical KUB385/CL100), and a 15 µm thick stretched nylon (printing layer) on the back of the gas barrier coating layer, and a polyurethane-based two-part adhesive (Gangnam Chemical KUB385/CL100) It was used and laminated, and it aged at 50 degreeC for 5 days, and produced the laminated body as shown in FIG.

<Comparative Example 7>

A polyethylene terephthalate (printed layer) having a thickness of 12 μm is prepared in lamination station 1 using the equipment applied to the extrusion lamination process as shown in FIG. 5, and the temperature of the extruder barrel is 300° C. and the die temperature is 300 ℃, and the extrusion rate is adjusted to 150kg/hr to melt the low-density polyethylene to form the first adhesive layer, and at the same time to laminate with the back surface of the gas barrier coating layer of the gas barrier film obtained in Comparative Example 3.

Then, in lamination station 2, the temperature of the extruder barrel was maintained at 300 ° C and the die temperature was maintained at 300 ° C. was melted to form a second adhesive layer, and at the same time, linear low-density polyethylene (sealant layer) was laminated to prepare a laminate as shown in FIG. 3 .

Evaluation of Gas Barrier Films

<Experimental Example 1: Water resistance evaluation>

On the surface of the coating layer of the gas barrier film obtained in Examples 1 to 6 and Comparative Examples 1 to 4, draw a square of 3 cm x 3 cm with an oil pen (black, red, blue), spray water on the surface, wait for 1 minute, and then wait for 1 minute with the oil pen Check the lifting degree of (black, red, blue). If there is no floating of the oil pen, it is judged that it has water resistance. Also, it is judged based on the degree of erasure by rubbing the area drawn with an oil-based pen using a cotton swab. The results are shown in Table 2.

Very Good: No Erasing + No Lifting

Good: Slightly erased + no lifting

Bad: erased

<Experimental Example 2: Evaluation of transmittance>

The gas barrier films obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were cut into a square size of 5 cm x 5 cm and measured using a transmittance measuring device (COH-5500 manufactured by DENSHOKU). The measurement method was described in accordance with ISO-13468-1. The results are shown in Table 2.

<Experimental Example 3: Haze Evaluation>

The gas barrier films obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were cut into a square size of 5 cm x 5 cm and measured using a haze measuring device (COH-5500 manufactured by DENSHOKU). The measurement method was written based on ISO-14782. The results are shown in Table 2.

<Experimental Example 4: Water vapor permeability>

The water vapor transmission rate was measured using the water vapor transmission rate measuring apparatus (PERMATRAN-W 3/34 manufactured by MOCON) under the conditions of a temperature of 37.8°C and a relative humidity of 100%. The measurement method was based on ASTM F1249, and the measurement value was expressed in unit [g/m ² ·day]. The results are shown in Table 2.

<Experimental Example 5: Oxygen Permeability>

The oxygen permeability was measured using an oxygen permeability measuring device (OXTRAN-22 manufactured by MOCON) under conditions of a temperature of 23°C and a relative humidity of 0%. The measurement method was based on ASTM D3985, and the measurement value was expressed in unit [cc/m ² ·day]. The results are shown in Table 2.

<Experimental Example 6: Evaluation of Adhesion>

The adhesion between the substrate and the coating layer of the gas barrier films obtained in Examples 1 to 6 and Comparative Examples 1 to 4 was subjected to a cross-cut test according to ASTM D3002, and the following characteristics were classified. The results are shown in Table 2 below.

Very good: No separation of coating surface

Good: Separation within 5% of coated surface

Bad: Separation of more than 65% of the coated side

Reference Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 water resistance - ◎ ◎ ◎ ◎ ◎ ◎ ○ ○ ○ ◎ Transmittance (%) 87 88 88 89 88 89 89 88 88 88 88 Haze (%) 2.2 1.8 1.7 1.7 1.8 1.7 1.7 1.8 1.8 1.9 1.8 Water vapor permeability 1.5 0.6 0.6 0.6 0.7 0.6 0.7 1.3 1.4 1.3 1.5 oxygen permeability 2.2 0.5 0.5 0.7 0.5 0.7 0.6 1.9 1.8 1.9 2.0 adhesion - ◎ ◎ ◎ ◎ ○ ◎ × × ◎ ×

◎: Very good ○: Good ×: Poor

As shown in Table 2, in Examples 1-6, the vapor-deposited layer and adhesive force were favorable and the gas barrier film excellent in barrier property was obtained. In addition, it was confirmed that the water resistance deteriorated in Comparative Examples 1 to 3 when the amount of methyl methacrylate capable of improving water resistance in the gas barrier composition was adjusted or when a small amount of the nano-silica dispersion was added. In addition, as in Comparative Example 4, when the nano-silica dispersion was included in an excessive amount, it was confirmed that the dispersibility deteriorated, the water vapor permeability and oxygen permeability were deteriorated, and the adhesion was also deteriorated.

Evaluation of gas barrier laminates

The physical properties of the gas barrier laminate in which the printing film, gas barrier film, and sealant film prepared in Examples 7 to 10 and Reference Examples 2 and Comparative Examples 5 to 7 were laminated were measured based on the following criteria.

<Experimental Example 1: Oxygen Permeability>

The oxygen permeability of the laminate after lamination was measured by the dry lamination process or the extrusion lamination process. The oxygen permeability was measured using an oxygen permeability measuring device (OXTRAN-22 manufactured by MOCON) under conditions of a temperature of 23°C and a relative humidity of 0%. The measurement method was based on ASTM D3985, and the measurement value was expressed in unit [cc/m ² ·day]. The results are shown in Table 3.

<Experimental Example 2: Peel strength evaluation>

The peel strength of the laminate laminate obtained by the dry lamination process or the extrusion lamination process was measured. Peel strength is measured at room temperature (20℃) in accordance with ASTM D 8827, the laminate is cut into strips with a width of 15 mm, the ends are partially peeled off, and subjected to a peel tester (manufactured by Shimadzu Corporation, product name EZ-TEST). T-type peeling was carried out at a rate of 100 mm/min by means of a method, and the adhesive strength (g/15 mm) between the substrate of the laminate and the gas barrier film was measured. The results are shown in Table 3.

<Experimental Example 3: 　High Temperature High Humidity Test>

The laminate laminate obtained by the dry lamination process or the extrusion lamination process was stored for 30 days under 85 degreeC x 85 RH%. After the high temperature, high humidity test, oxygen permeability and adhesive strength between the substrate of the laminate and the gas barrier film were measured by the methods of Experimental Examples 1 and 2. The results are shown in Table 3.

oxygen permeability peel strength rescue After lamination ^※1 After the test ^※2 After lamination ^※1 After the test ^※2 Example 7 0.5 0.6 non-peelable non-peelable NY/Example 1/CPP Example 8 0.6 0.6 Non-peelable non-peelable NY/Example 6/LLDPE Example 9 0.5 0.6 non-peelable non-peelable PET/PE/Example 1/PE/LLDPE Example 10 0.6 0.6 non-peelable non-peelable PET/PE/Example 6/PE/LLDPE Reference Example 2 0.6 0.7 non-peelable non-peelable NY/EVOH/LLDPE Comparative Example 5 not measurable not measurable room temperature peeling room temperature peeling PET/PE/EVOH/PE/LLDPE Comparative Example 6 1.9 2.5 non-peelable 200 NY/Comparative Example 3/CPP Comparative Example 7 4.0 7.2 non-peelable 250 PET/PE/Comparative Example 3/PE/LLDPE

_{※1 Example 1 Oxygen permeability of the gas barrier film 0.5cc/m2·day, Example 6 Oxygen permeability of the gas barrier film 0.6cc/m2·day}

_{※2 Measured after high-temperature, high-humidity test in which the laminate laminate is stored at 85°C × 85 RH% for 30 days}

As shown in Table 3, in the laminates of Examples 7 and 8, even when the gas barrier film was laminated by a curing reaction using a polyurethane-based adhesive, the oxygen permeability was maintained the same without deterioration and did not peel at room temperature. In addition, in the laminates of Examples 9 and 10, the oxygen permeability of the gas barrier film was maintained without deterioration even by the heat of oxidation of the low-density polyethylene extruded at a high temperature of 300° C. by the extrusion lamination process. In addition, in the laminates of Examples 7 to 10, heat resistance was strengthened, and excellent oxygen permeability was maintained even after a high temperature and high humidity test.

The gas barrier laminate produced by the dry lamination process using the conventional ethylene-vinyl alcohol film of Reference Example 2 is suitable for use as a packaging material because oxygen permeability does not deteriorate. The ethylene-vinyl alcohol film deteriorated due to the oxidation heat of low-density polyethylene manufactured and extruded at a high temperature of 300° C.

In addition, the laminate of Comparative Examples 6 to 7 is a case of using the gas barrier film of Comparative Example 3 in which the amount of the nano-silica dispersion is adjusted to a small amount, and the supplementary action of heat resistance by the inorganic material is poor, oxygen permeability is deteriorated, and peeling strength is also falling confirmed that.

10: polyamide-based plastic film 20: inorganic compound deposition layer
30: organic-inorganic coating layer 40: printing film
50: sealant layer 60, 70: low density polyethylene adhesive layer
100: gas barrier film 200, 300: gas barrier laminate

Claims (28)

polyamide-based plastic film;
a gas barrier deposition layer provided on the film and including an inorganic compound; and
An organic-inorganic coating layer installed on the gas barrier deposition layer and formed of a gas barrier coating composition having water resistance including an acrylic polymer and a silica nanoparticle dispersion is laminated,
The acrylic polymer is based on 100 parts by weight of the total monomer.
(a) a total of 70 to 90 parts by weight of at least one or more monomers selected from alkyl (meth)acrylate monomers having C1-C15 carbon atoms in the alkyl group, (b) at least one selected from copolymerizable monomers containing a hydroxyl group 1 to 10 parts by weight of the above monomers, and (c) an acrylic polymer polymerized including 5 to 25 parts by weight of at least one or more monomers in total selected from copolymerizable monomers containing a carboxyl group,
Among the alkyl (meth) acrylate monomers, methyl methacrylate is included in a proportion of at least 30 parts by weight or more,
The silica nanoparticle dispersion is contained in an amount of 5 to 20 parts by weight based on 90 parts by weight of the acrylic polymer, and the silica particle size is a gas barrier coating composition having an average particle diameter of 1 nm to 50 nm,
The gas barrier film has an oxygen permeability of 0.7 cc/m ² ·day or less.
The gas barrier film according to claim 1, wherein the polyamide-based plastic film is a nylon film.
The method according to claim 1, wherein the inorganic compound is one or two inorganic transparent oxides selected from the group consisting of AlOx, AlNx, AlOxNy, TiOx, SiOx, ZnOx, SnOx, SiNx, SiOxNy, NiOx and MgO. gas barrier film.
The gas barrier film according to claim 3, wherein the inorganic compound is AlOx.
delete The gas barrier film according to any one of claims 1 to 4, wherein the acrylic polymer has a weight average molecular weight of 100,000 to 500,000.
The gas barrier film according to any one of claims 1 to 4, wherein the acrylic polymer has a glass transition temperature of 20°C or higher.
delete delete [Claim 5] The gas barrier film according to any one of claims 1 to 4, wherein the methyl methacrylate is included in an amount of 70 parts by weight or less of the alkyl (meth)acrylate monomer.
The gas barrier film according to any one of claims 1 to 4, wherein the copolymerizable monomer containing a hydroxyl group is an acrylate-based monomer.
12. The method of claim 11, wherein the acrylate-based monomer is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-chloropropyl (meth) acrylate, 4 -Hydroxybutyl (meth)acrylate, acyloctyloxy-2-hydroxypropyl (meth)acrylate, methyl α-hydroxymethyl acrylate, ethyl α-hydroxymethyl acrylate, propyl α-hydroxymethyl acrylate A gas barrier film, characterized in that it is a compound selected from the group consisting of lactate and butyl α-hydroxymethyl acrylate.
According to any one of claims 1 to 4, wherein the copolymerizable monomer containing a carboxyl group is methacrylic acid, acrylic acid, ethyl acrylic acid, butyl acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, monomethyl maleic acid and a compound selected from the group consisting of 5-norbornene-2-carboxylic acid.
[Claim 5] The gas barrier film according to any one of claims 1 to 4, wherein the carboxyl group present in the acrylic polymer is present in the form of a salt of 30% or more.
The gas barrier film according to any one of claims 1 to 4, further comprising a silane coupling agent in the coating composition.
The gas barrier film according to claim 15, wherein the silane coupling agent is an epoxy-based silane coupling agent.
The gas barrier film according to claim 15, wherein the silane coupling agent is added in an amount of 0.1 to 5.0 parts by weight based on 90 parts by weight of the acrylic polymer.
[Claim 5] The gas barrier film according to any one of claims 1 to 4, further comprising a monomer represented by the following Chemical Formula 1 during polymerization of the acrylic polymer.
[Formula 1]

In the above formula,
R ₁ is hydrogen or C1-C4 alkyl;
R ₂ is C1-C4 alkyl.
The gas barrier film according to claim 18, wherein the monomer represented by Formula 1 is glycidyl methacrylate or glycidyl acrylate.
The gas barrier film according to claim 18, wherein the monomer represented by Chemical Formula 1 is further included in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the total monomer during polymerization of the acrylic polymer.
The gas barrier film according to claim 1;
a sealant film installed on the back of the plastic film of the gas barrier film; and
A gas barrier laminate comprising a printing film provided on the back surface of the organic-inorganic coating layer of the gas barrier film.
The gas barrier laminate according to claim 21, wherein the printing film is a polyester-based film or a polyamide-based film.
22. The gas barrier laminate according to claim 21, wherein the sealant film is a polyethylene film or a polypropylene film.
22. The method of claim 21, wherein the printing film, the gas barrier film, and the sealant film are laminated by an adhesive for dry lamination, and even after lamination, the oxygen permeability is maintained at 0.7cc/m ² ·day or less. gas barrier laminate.
The method of claim ²¹ , wherein the printing film, the gas barrier film, and the sealant film are laminated by extruding a polyethylene-based resin at a high temperature of 280 to 320 ° C. A gas barrier laminate with reinforced heat resistance.
forming a gas barrier deposition layer including an inorganic compound on the polyamide-based plastic film directly or through an anchor coat layer;
Preparing a gas barrier coating composition according to claim 1 comprising an acrylic polymer and a silica nanoparticle dispersion;
preparing the gas barrier film according to claim 1 by applying the coating composition directly on the gas barrier deposition layer or through an anchor coat layer to form an organic-inorganic coating layer;
forming an adhesive layer in a dry adhesive state by applying an adhesive for dry lamination to the backside of the plastic film and/or the backside of the organic-inorganic coating layer and evaporating to dryness at 70 to 90°C;
Laminating the sealant film by pressure bonding to the adhesive layer of the plastic film, and pressure bonding the printing film to the adhesive layer of the organic-inorganic coating layer;
The heat-resistance-reinforced according to claim 24, characterized in that a printing film, a gas barrier film, and a sealant film are laminated through a dry lamination process, which includes the step of aging the laminated laminate at 40-50° C. for 3 to 7 days. A method for manufacturing a gas barrier laminate.
forming a gas barrier deposition layer including an inorganic compound on the polyamide-based plastic film directly or through an anchor coat layer;
Preparing a gas barrier coating composition according to claim 1 comprising an acrylic polymer, and a silica nanoparticle dispersion;
preparing the gas barrier film according to claim 1 by applying the coating composition directly on the gas barrier deposition layer or through an anchor coat layer to form an organic-inorganic coating layer;
Putting a polyethylene-based resin into an extruder and melt-extruding it at a high temperature of 280 to 320° C. to form a first adhesive layer on one surface of the printing film, while integrally bonding the gas barrier film to the back surface of the first adhesive layer and laminating;
A polyethylene-based resin is put into an extruder on the back side of the gas barrier film and melt-extruded at a high temperature of 280 to 320° C. to form a second adhesive layer, while simultaneously laminating a sealant film on the back surface of the second adhesive layer. A method of manufacturing a gas barrier laminate with reinforced heat resistance according to claim 25, characterized in that a gas barrier film and a sealant film are laminated through an extrusion lamination process.
A ready-to-eat food packaging material for boiling and retort comprising the gas barrier film according to any one of claims 1 to 4.

Images