JP7319800B2 - Barrier coating composition and composite film - Google Patents

Description

The present invention relates to a barrier coating composition and a composite film having a coated layer formed using the barrier coating composition.

In the field of packaging bags used for food packaging, there are many cases in which packaging bags are manufactured that have a function of being able to be treated with hot water and that allow the contents to be easily cooked together with the bag.
A packaging bag for hot water treatment has a high sterilizing effect, and since the packaging bag is completely sealed, the content is less likely to rot, making it an effective means for long-term storage. However, if the gas barrier properties are not sufficient, oxygen will enter the packaging bag during storage, causing alteration and deterioration of the contents. Therefore, in a packaging bag for hot water treatment, the extent to which permeation of oxygen and the like can be suppressed is a major factor in determining the value of the packaging bag.

2. Description of the Related Art Conventionally, in packaging bags used for packaging food, medical care, and the like, methods of providing various gas barrier layers in order to block gases such as oxygen and water vapor have been considered. In particular, metals and metal oxides that are laminated on printed substrate films or the like by a vapor deposition method have been used as materials having high gas barrier properties. Among the above-mentioned hot water treatment packaging bags, for long-term storage, hot water treatment packaging bags laminated with an aluminum deposition film or foil of aluminum itself have become mainstream. However, composite laminate films using these materials are generally expensive. Moreover, it has a problem that it cannot be used in fields where transparency is required.

In recent years, the use of a gas barrier film provided with a base film made of a plastic material, a deposited layer made of a metal oxide, and a coating layer made of a resin has been studied.
As such a gas barrier film, for example, a gas barrier film in which a coating layer contains an aqueous polyurethane resin and a water-soluble polymer has been proposed (see, for example, Patent Document 1). Further, for example, a transparent gas barrier film having a top coat layer containing polyurethane resin and polyvinyl alcohol has been proposed (see, for example, Patent Document 2).

A gas barrier film having a laminated structure is required to have not only excellent gas barrier properties but also excellent laminate strength. In the field of packaging bags used for food and medical packaging applications, in addition to excellent gas barrier properties, not only lamination strength under normal (dry) conditions, but also lamination strength under wet conditions is required. ing.
Furthermore, in the medical field, there is a demand for a laminate having extremely excellent lamination strength that can withstand sterilization treatment at high temperature and high pressure.

JP 2012-020433 A JP 2017-222151 A

Therefore, an object of the present invention is to obtain a composite film that not only excels in lamination strength, seal strength, water vapor barrier property and oxygen barrier property under normal and wet conditions, but also has excellent lamination strength even after high-temperature and high-pressure treatment. It is another object of the present invention to provide a barrier coating composition that is capable of forming a barrier coating composition, and to provide a composite film obtained using the barrier coating composition.

As a result of repeated research, the present inventors have found that by using a coating composition containing an aqueous polyurethane resin, a highly polar resin having a silanol group, and a silane coupling agent, when the coating composition is applied It has excellent cohesive strength of the coating film and extremely excellent adhesion to vapor deposited films made of metal oxides, etc., so it not only has excellent lamination strength, seal strength, water vapor barrier property and oxygen barrier property under normal and wet conditions. , found that a composite film having excellent lamination strength can be obtained even after high-temperature and high-pressure treatment, and completed the present invention.

That is, the barrier coating composition of the present invention is characterized by containing an aqueous polyurethane resin, a highly polar resin having a silanol group, and a silane coupling agent.

In the barrier coating composition of the present invention, the mass ratio of the highly polar resin having a silanol group to 100 parts by mass of the aqueous polyurethane resin is preferably 15 to 150 parts by mass.
In the highly polar resin having silanol groups, the content of silanol groups in the molecule is preferably 0.05 to 3 mol % as a monomer unit.
The silane coupling agent is preferably a silane coupling agent having an epoxy group.
The barrier coating composition of the present invention is preferably for laminates.
The present invention also provides a composite film comprising at least a substrate film, a vapor deposition layer, and a coating layer in this order, wherein the coating layer is formed by applying the barrier coating composition. It is also a composite film characterized by
In the composite film of the present invention, the deposited layer is preferably one or more deposited layers selected from the group consisting of silica and alumina.
The barrier coating composition and composite film are described in detail below.

[Barrier coating composition]
First, the barrier coating composition of the present invention will be described.
The barrier coating composition of the present invention contains an aqueous polyurethane resin, a highly polar resin having a silanol group, and a silane coupling agent.

The water-based polyurethane resin preferably contains an acid group-containing polyurethane resin and a polyamine compound from the viewpoint of suitably exhibiting gas barrier properties such as water vapor barrier properties and oxygen barrier properties.
The aqueous polyurethane resin may be a mixture or a copolymer of the acid group-containing polyurethane resin and the polyamine compound.
The bond between the acid group of the acid group-containing polyurethane resin and the polyamine compound is not particularly limited, and may be an ionic bond (for example, an ionic bond between a carboxyl group and a tertiary amino group) or a covalent bond. It may be a bond (eg, an amide bond, etc.).

The acid group of the acid group-containing polyurethane resin may be any acid group as long as it can bond with the amino group (primary amino group, secondary amino group, tertiary amino group, etc.) of the polyamine compound. , a sulfonic acid group, and the like. The above acid groups are usually neutralizable with a neutralizing agent (base) and may form a salt with a base.
The acid group may be located at the end of the acid group-containing polyurethane resin or may be located in a side chain, but is preferably located at least in the side chain.

The acid value of the acid-group-containing polyurethane resin is preferably 5 to 100 mgKOH/g, more preferably 10 to 70 mgKOH/g, from the viewpoint of suitably expressing gas barrier properties and water resistance. More preferably 15 to 60 mgKOH/g.
In addition, in this specification, an acid value means the acid value measured by the method according to JISK0070.

The total of the urethane group concentration and the urea group (urea group) concentration of the acid group-containing polyurethane resin is preferably 15% by mass or more, more preferably 20 to 60% by mass, from the viewpoint of appropriately expressing gas barrier properties. is more preferred.
The urethane group concentration means the ratio of the molecular weight (59 g/equivalent) of the urethane group to the molecular weight of the repeating structural unit of the polyurethane resin.
The urea group concentration is the ratio of the molecular weight of the urea group (primary amino group (amino group): 58 g/equivalent, secondary amino group (imino group): 57 g/equivalent) to the molecular weight of the repeating structural unit of the polyurethane resin. means
When a mixture of two or more types of acid group-containing polyurethane resin is used, the urethane group concentration and the urea group concentration can be calculated based on the amount of reaction components charged, that is, the proportion of each component used.

The acid-group-containing polyurethane resin usually has at least rigid units (units composed of hydrocarbon rings) and short-chain units (eg, units composed of hydrocarbon chains). That is, the constituent units of the acid group-containing polyurethane resin are usually derived from a polyisocyanate component, a polyhydroxy acid component, a polyol component, or a chain extender component (particularly, at least the polyisocyanate component) to form a hydrocarbon ring (aromatic and at least one non-aromatic hydrocarbon ring). The ratio of units composed of hydrocarbon rings in the structural units of the acid group-containing polyurethane resin is 10 to 70% by mass based on the total of all structural units, from the viewpoint of suitably exhibiting gas barrier properties and laminate strength. preferably 15 to 65% by mass, and even more preferably 20 to 60% by mass.

The number average molecular weight of the acid group-containing polyurethane resin can be appropriately selected, but is preferably 800 to 1,000,000, more preferably 800 to 200,000, and more preferably 800 to 100,000. It is even more preferable to have When the number average molecular weight of the acid group-containing polyurethane resin is within the above range, the viscosity of the barrier coating composition can be made suitable, and the gas barrier properties of the coating layer can be suitably imparted.
In addition, in this specification, a number average molecular weight is a value of standard polystyrene conversion measured by a gel permeation chromatography (GPC).

The acid group-containing polyurethane resin may be crystalline in order to improve gas barrier properties.
The glass transition temperature (Tg) of the acid group-containing polyurethane resin is preferably from 100 to 200°C, more preferably from 110 to 180°C, and even more preferably from 115 to 150°C, from the viewpoint of suitably exhibiting gas barrier properties.
In addition, in this specification, a glass transition temperature (Tg) is a value measured by differential scanning calorimetry (DSC).

The polyamine compound is preferably a compound having two or more basic nitrogen atoms.
The basic nitrogen atom is a nitrogen atom that can bond with the acid group of the acid group-containing polyurethane resin. A nitrogen atom is mentioned.
The polyamine compound is not particularly limited as long as it can bond with the acid group of the acid group-containing polyurethane resin to improve gas barrier properties, and various compounds having two or more basic nitrogen atoms are used. be able to.
As the polyamine compound, a polyamine compound having two or more amino groups of at least one kind selected from the group consisting of primary amino groups, secondary amino groups and tertiary amino groups is preferable.

Specific examples of the polyamine compound include alkylenediamines, polyalkylenepolyamines, silicon compounds having a plurality of basic nitrogen atoms, and the like. Examples of the alkylenediamines include alkylenediamines having 2 to 10 carbon atoms such as ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,4-butanediamine, and 1,6-hexamethylenediamine. is mentioned. Examples of the polyalkylenepolyamines include tetraalkylenepolyamine. Examples of the silicon compound having a plurality of basic nitrogen atoms (including nitrogen atoms such as amino groups) include 2-[N-(2-aminoethyl)amino]ethyltrimethoxysilane, 3-[N-(2 silane coupling agents having a plurality of basic nitrogen atoms such as -aminoethyl)amino]propyltriethoxysilane;
Note that the silane coupling agent that corresponds to the polyamine compound does not correspond to the above silane coupling agent.

The amine value of the polyamine compound is preferably 100 to 1900 mgKOH/g, more preferably 150 to 1900 mgKOH/g, more preferably 200 to 1900 mgKOH, from the viewpoint of suitably expressing gas barrier properties and the water dispersion stability of the aqueous polyurethane resin. /g is more preferred, 200-1700 mgKOH/g is particularly preferred, and 300-1500 mgKOH/g is most preferred. The amine value of the above polyamine compound is measured by the following method.
[Method for measuring amine value]
Accurately weigh 0.5 to 2 g of the sample (sample amount Sg). 30 g of ethanol is added to the precisely weighed sample to dissolve it. Bromophenol blue is added to the resulting solution as an indicator, and titration is performed with a 0.2 mol/L ethanolic hydrochloric acid solution (potency f). The point at which the color of the solution changes from green to yellow is defined as the end point, and the titration amount (AmL) at this time is used to obtain the amine value using the following formula 1.
Formula 1: Amine value = A x f x 0.2 x 56.108/S [mgKOH/g]

In the aqueous polyurethane resin, the content of the polyamine compound is such that the molar ratio (acid group/basic nitrogen atom) of the acid group of the acid group-containing polyurethane resin and the basic nitrogen atom of the polyamine compound is 10/1. An amount of up to 0.1/1 is preferred, and an amount of 5/1 to 0.2/1 is more preferred. When the acid group/basic nitrogen atom content is within the above range, the crosslinking reaction between the acid group of the acid group-containing polyurethane and the polyamine compound appropriately occurs, and excellent oxygen barrier properties can be suitably exhibited in the coat layer. .

The aqueous polyurethane resin is usually used in the form of a dispersion in an aqueous medium (aqueous dispersion).
Examples of the aqueous medium include water, water-soluble or hydrophilic organic solvents, and mixtures thereof. Examples of the water-soluble or hydrophilic organic solvent include alcohols such as methanol, ethanol and isopropanol; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; cellosolves; etc.
As the aqueous medium, water or a medium containing water as a main component is preferable. The content of water in the aqueous medium is preferably 70% by mass or more, more preferably 80% by mass or more.
The aqueous medium may or may not contain a neutralizing agent (base) that neutralizes the acid groups of the acid group-containing polyurethane resin. Neutralizing agents are usually included.

In the aqueous dispersion of the aqueous polyurethane resin, the average particle size of the dispersed particles (polyurethane resin particles) is not particularly limited. From the viewpoint of ensuring the above and suitably expressing gas barrier properties, the thickness is preferably 20 nm to 500 nm, more preferably 25 nm to 300 nm, and more preferably 30 nm to 200 nm.
In this specification, the average particle size is measured by a concentrated particle size analyzer (FPAR-10 manufactured by Otsuka Electronics Co., Ltd.) in a state where the solid content concentration is 0.03 to 0.3% by mass (diluted with water). It is a value measured by

As the water-based polyurethane resin, a commercially available one may be used, or one produced by a known production method may be used.
The method for producing the water-based polyurethane resin is not particularly limited, and conventional techniques for making water-based polyurethane resins, such as the acetone method and prepolymer method, are used. In the urethanization reaction, urethanization catalysts such as amine-based catalysts, tin-based catalysts and lead-based catalysts may be used as necessary.
For example, in an inert organic solvent such as ketones such as acetone, ethers such as tetrahydrofuran, and nitriles such as acetonitrile, a polyisocyanate compound, a polyhydroxy acid, and, if necessary, a polyol component and a chain extender component The acid group-containing polyurethane resin can be prepared by reacting with at least one of More specifically, a polyisocyanate compound, a polyhydroxy acid, and a polyol component are reacted in an inert organic solvent (particularly, a hydrophilic or water-soluble organic solvent) to form a prepolymer having an isocyanate group at the end. After producing a polymer, neutralizing it with a neutralizing agent and dissolving or dispersing it in an aqueous medium, a chain extender component is added and reacted, and the organic solvent is removed to obtain an aqueous solution of the acid group-containing polyurethane resin. Dispersions can be prepared.
An aqueous polyurethane resin in the form of an aqueous dispersion can be prepared by adding the polyamine compound to the aqueous dispersion of the acid group-containing polyurethane resin thus obtained, and heating if necessary.
When heating, the heating temperature is preferably 30 to 60.degree.

The barrier coating composition of the present invention contains a highly polar resin having silanol groups.
The highly polar resin having a silanol group not only has excellent bonding properties with the silane coupling agent described later, but also can provide a large number of connection points with the vapor deposition layer described later. Therefore, the coating composition of the present invention The coating film has excellent cohesive strength and excellent adhesion to the vapor deposition layer, so it not only has excellent lamination strength, seal strength, water vapor barrier properties and oxygen barrier properties under normal and wet conditions, but also after high temperature and high pressure treatment. A composite film having excellent lamination strength can also be obtained.
Here, "high temperature and high pressure treatment" means a treatment of immersion in hot water under conditions of 120°C and 2 atmospheres for 30 minutes. Excellent lamination strength even after processing.

The highly polar resin having a silanol group means a resin having a silanol group and the following highly polar functional groups.
Examples of the highly polar functional groups include amino groups, ester groups, carboxyl groups, sulfone groups, cyano groups, thiol groups, and hydroxyl groups.
Among them, a hydroxyl group and a carboxyl group are preferable, and a hydroxyl group is more preferable, from the viewpoint of suitably expressing gas barrier properties.
Such a highly polar resin has excellent solubility in solvents such as water, and is also excellent in compatibility with the above-described aqueous dispersion of the aqueous polyurethane resin. can be obtained.

Examples of the highly polar resin having a silanol group include silanol-modified polyvinyl alcohol.
The silanol-modified polyvinyl alcohol can be obtained, for example, by radically copolymerizing a silanol group-containing alkylene monomer with a lower fatty acid vinyl ester and saponifying the resulting copolymer.
Examples of the alkylene monomer include linear or branched C2-12 olefin compounds such as ethylene, propylene, isobutylene, α-octene, α-dodecene, and α-octadecene. vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl versatate, etc. .

The highly polar resin having silanol groups preferably has a silanol group content in the molecule of 0.05 to 3.0 mol % as a monomer unit.
When the content of the silanol group is within the above range, the solubility in water and alcohol can be improved.
The content of the highly polar resin having silanol groups is more preferably 0.1 to 2.0 mol %.

The highly polar resin having a silanol group preferably has a silanol group in its side chain.
By having a silanol group in the side chain, water resistance can be improved.
In addition, in this specification, the longest chain forming the polymer is referred to as "main chain", and the other chains are referred to as "side chains".

The degree of saponification of the highly polar resin having silanol groups is preferably 90 to 100%, more preferably 95 to 100%, even more preferably 97 to 100%.

The highly polar resin having a silanol group preferably has an average degree of polymerization of 200 to 3,000, more preferably 400 to 2,000.
By setting the average degree of polymerization within the above range, the viscosity of the coating composition does not increase too much, it is easy to uniformly mix with other components, and the gas barrier properties of the coating layer and peel strength with other layers are achieved. can be suitably applied.

The highly polar resin having a silanol group may be commercially available, or may be produced by a known production method to satisfy the above silanol group content, saponification degree, average polymerization degree, and the like.
Commercially available products of the highly polar resin having a silanol group include R-1130, R-2105 and R-2130 (manufactured by Kuraray Co., Ltd.).

The total content of the water-based polyurethane resin and the highly polar resin having a silanol group is preferably 0.5 to 30 parts by mass in solid content with respect to 100 parts by mass of the barrier coating composition of the present invention. , more preferably 1 to 15 parts by mass.

The mass ratio (mass ratio of solid content) of the highly polar resin having a silanol group to 100 parts by mass of the aqueous polyurethane resin is preferably 15 to 150 parts by mass, more preferably 20 to 100 parts by mass. .
By setting it as the said range, water resistance and gas-barrier property can be compatible suitably.

Examples of the silane coupling agent include compounds represented by RSiX ₃ (wherein R is an organic reactive group and X is an alkoxy group).
Examples of the organic reactive group include those having an amino group, (meth)acryl group, epoxy group, vinyl group, mercapto group, isocyanate group, isocyanurate group, and the like.
In addition, in this specification, a (meth)acryl group indicates both an acryl group and a methacryl group.
Moreover, examples of the alkoxy group include a methoxy group and an ethoxy group.

Examples of the silane coupling agent include a silane coupling agent having a vinyl group, a silane coupling agent having an epoxy group, a silane coupling agent having an amino group, a silane coupling agent having a mercapto group, a (meth) acrylic Examples include a silane coupling agent having a group, a silane coupling agent having an isocyanate group, and a silane coupling agent having an isocyanurate group.
Examples of the silane coupling agent having a vinyl group include vinyltrimethoxysilane and vinyltriethoxysilane. As the silane coupling agent having an epoxy group, 2(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxy propylmethyldimethoxysilane, 3-glycidoxypropylethyldiethoxysilane, and the like. Examples of the silane coupling agent having an amino group include 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane. Examples of the silane coupling agent having a mercapto group include 3-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane. Examples of the silane coupling agent having a (meth)acryl group include 3-acryloxypropyltrimethoxysilane. Examples of the silane coupling agent having an isocyanate group include 3-isocyanatopropyltriethoxysilane. Examples of the silane coupling agent having the isocyanurate group include tris-(trimethoxysilylpropyl)isocyanurate.
Any one of these silane coupling agents may be used alone, or two or more thereof may be used in combination.

As the silane coupling agent, those having reactivity with other components in the barrier coating composition are preferably used. Among them, a silane coupling agent having an epoxy group is preferable.
The silane coupling agent having an epoxy group has good reactivity with the functional groups of the water-based polyurethane resin and the highly polar resin having a silanol group, and has excellent reactivity with the vapor deposition layer described later. , lamination strength and gas barrier properties can be suitably improved.

The silane coupling agent is preferably 1 to 30 parts by mass with respect to 100 parts by mass of the barrier coating composition of the present invention.

The barrier coating composition of the present invention preferably contains a solvent. As the solvent, both aqueous and non-aqueous solvents can be used as long as they can dissolve the aqueous polyurethane resin, the highly polar resin having a silanol group, and the silane coupling agent.
As the solvent, it is preferable to use a mixed solvent of water and a lower alcohol.
Examples of the lower alcohol include lower alcohols having 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, sec-butyl alcohol and tert-butyl alcohol. Examples include alcohols, and those containing at least one of these can be preferably used.

The amount of the solvent is preferably 5 to 60 parts by mass, more preferably 20 to 50 parts by mass, per 100 parts by mass of the barrier coating composition of the present invention.

The barrier coating composition of the present invention contains inorganic fine particles such as silica, talc, alumina, calcium carbonate, titanium oxide, magnesium carbonate, clay, kaolin, etc., colloidal silica, surfactants, etc., which are generally known as antiblocking agents. May be blended.

Since the barrier coating composition of the present invention has the structure described above, it can be suitably used for lamination of packaging materials and the like.

[Method for producing barrier coating composition]
The method for producing the barrier coating composition of the present invention is not particularly limited. A coating liquid having a predetermined concentration can be prepared by sufficiently stirring and mixing at room temperature.
When the silane coupling agent is added, it is preferable to add it while slowly stirring it, because if it is added all at once, it may aggregate.

[Composite film]
A composite film comprising at least a substrate film, a deposited layer and a coat layer in this order, wherein the coat layer is formed by applying the barrier coating composition. is also one of the present invention.

The base film is not particularly limited as long as it is made of a thermoplastic resin or the like having the ability to form a transparent film.
Examples of the resin used as the base film include polyethylene (low density, high density), ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, polypropylene, Polyolefin resins such as ethylene-vinyl acetate copolymers, ethylene-methyl methacrylate copolymers, and ionomer resins; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; nylon-6, nylon-6,6, Metaxylene diamine-adipic acid condensation polymer, amide resin such as polymethyl methacrylimide, acrylic resin such as polymethyl methacrylate; polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, polyacrylonitrile, etc. styrene, acrylonitrile-based resin; cellulose triacetate, hydrophobized cellulose-based resin such as cellulose diacetate; polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, halogen-containing resin such as Teflon (registered trademark); polyvinyl alcohol, ethylene- Hydrogen-bonding resins such as vinyl alcohol copolymers and cellulose derivatives; engineering plastic resins such as polycarbonate resins, polysulfone resins, polyethersulfone resins, polyetheretherketone resins, polyphenylene oxide resins, polymethylene oxide resins, and liquid crystal resins etc. These may be used alone or in combination of two or more.
The substrate film is preferably subjected to surface treatment such as plasma treatment or corona discharge treatment on the side on which the vapor deposition layer and the coating layer are provided.

The thickness of the substrate film is not particularly limited, but is preferably 0.5 to 1000 μm, more preferably 1 to 500 μm, still more preferably 1 to 100 μm, and particularly preferably 1 to 50 μm.

The deposition layer is preferably formed on the substrate film by vacuum deposition of an inorganic oxide, sputtering, plasma vapor deposition (PVD, CVD) or the like.
Examples of the inorganic oxides include oxides such as metals such as silicon, aluminum, zinc, tin, iron and manganese, and inorganic compounds containing one or more of these metals.
Among them, one or more deposited layers selected from the group consisting of silica and alumina are preferable because they have excellent adhesion to the coating layer formed by applying the barrier coating composition of the present invention.

The thickness of the deposition layer is not particularly limited, but is preferably 0.1 to 500 nm, more preferably 0.5 to 40 nm.

The coat layer can be formed by applying the barrier coating composition.
The coating method of the above-mentioned barrier coating composition is not particularly limited, but roll coating method using a gravure cylinder or the like, doctor knife method, air knife/nozzle coating method, bar coating method, spray coating method, dip coating method and the like. A coating method or the like in which these methods are combined can be used.

The thickness of the coating layer is not particularly limited, but is preferably 0.01 to 5 μm, more preferably 0.1 to 2 μm.
If the coat layer is thinner than 0.01 μm, it may be difficult to obtain high gas barrier properties, and if it exceeds 5 μm, no significant improvement in gas barrier properties may be observed.

The composite film of the invention may have a printed layer.
As the above-mentioned printed layer (printed layer for contents display and decorative function), an organic solvent-based printing ink composition, a water-based printing ink composition, etc., which have been conventionally used in flexible packaging, are usually used by gravure printing method or the like. It can be formed by printing with a flexographic printing method.

Examples of the organic solvent-based printing ink composition include, for example, an aromatic/non-aromatic mixed organic solvent-based printing ink composition containing a pigment and a polyurethane resin, and JP-A-01-261476 (pigment, polyurethane resin , Aromatic/non-aromatic mixed organic solvent printing ink composition containing chlorinated polypropylene), Japanese Patent Publication No. 07-113098 (non-aromatic organic solvent printing ink composition containing pigment and polyurethane resin), Organic solvent-based printing ink compositions disclosed in JP-A-07-324179 (pigment, polyurethane resin, non-aromatic/non-ketone organic solvent-based printing ink composition), and the like.

Examples of the water-based printing ink composition include JP-A-06-155694 (water-based printing ink composition containing pigment, acrylic binder resin, hydrazine-based crosslinking agent), JP-A-06-206972 (pigment, water , Aqueous Printing Ink Compositions Containing a Polyurethane Binder Resin).

Recently, as environmentally friendly inks, water-based printing ink compositions and even organic solvent-based printing ink compositions that do not use aromatic and ketone organic solvents as much as possible have been used. However, these can be preferably used.
Furthermore, the barrier composite film of the present invention may have other functional layers such as an ultraviolet shielding layer, an antibacterial layer, an adhesive layer, a sealant layer and the like.

The adhesive layer is preferably formed between the base film and the deposited layer, or between the coat layer and the sealant layer.
The adhesive layer can be formed by appropriately selecting an adhesive composition conventionally used in the production of composite laminate films for packaging and using various coating means.
Examples of the adhesive composition include various adhesives such as urethane-based, polyester-based and acrylic-based adhesives, and various adhesives such as titanium-based, isocyanate-based, imine-based and polybutadiene-based adhesives.

The sealant layer is a heat-sealable sheet material conventionally used for flexible packaging, and examples thereof include polyethylene film and polypropylene film.
The sealant layer may be formed by laminating hot-melt polymers such as low-density polyethylene, ethylene-vinyl acetate copolymer, and polypropylene polymer in a molten state and forming them into a film by cooling.

[Method for producing composite film]
The method for producing the composite film of the present invention is not particularly limited, and conventional methods can be appropriately selected and used.
For example, the following methods (a) to (d) can be mentioned.
(a) A base film (the base film may be a laminated film having a vapor deposition layer) is coated with the barrier coating composition and the adhesive composition sequentially after forming a vapor deposition layer by the method described above. A method of obtaining a composite film by laminating a sealant layer after processing.
(b) After forming a vapor deposition layer on a base film (the base film may be a laminated film having a vapor deposition layer) by the method described above, the above adhesive composition, barrier coating composition, and adhesive A method of obtaining a composite film by laminating a sealant layer after sequentially applying compositions.
(c) A base film (the base film may be a laminated film having a vapor deposition layer) is formed with a vapor deposition layer by the method described above, and then printed with an ink composition to form a printed layer. Then, a method of obtaining a composite film by sequentially applying the adhesive composition, the barrier coating composition, and the adhesive composition, and then laminating a sealant layer.
(d) After forming a vapor deposition layer on a base film (the base film may be a laminated film having a vapor deposition layer) by the method described above, the above adhesive composition, barrier coating composition, and adhesive For example, the composition is sequentially applied, the ink composition is printed to form a printed layer, and a sealant layer is further laminated to obtain a barrier composite film.

As for the coating method of the above-mentioned adhesive composition, a roll coating method using a conventional gravure cylinder or the like, a doctor knife method, an air knife/nozzle coating method, a bar coating method, a spray coating method, a dip coating method, and these methods can be used. A coating method or the like in which the methods of (1) and (2) are combined can be used.
Moreover, in order to form the said printing layer, a gravure printing method and a flexographic printing method can be normally used.

In the composite film of the present invention, the film thickness (after drying) of the adhesive layer is preferably 2 to 3 μm.
If the thickness of the adhesive layer is less than 2 μm, the adhesiveness between the coat layer and other layers may decrease, while if the thickness is greater than 3 μm, the adhesiveness does not increase commensurate with the increase in thickness. Also, when the composite film is used as a packaging bag, it may not be possible to obtain good handleability.
In addition, when a coating film having a film thickness within the above range cannot be obtained by one coating, it is also possible to perform multiple coatings.

Even when other functional layers are provided, a suitable barrier composite film can be produced by combining the methods (a) to (d) described above with good means for providing each functional layer. .

Since the barrier coating composition of the present invention has the constitution described above, it is possible to obtain a composite film excellent in lamination strength, seal strength, water vapor barrier property and oxygen barrier property under boiling conditions and wet conditions.
Moreover, the composite film of the present invention can be suitably used as a barrier film, a packaging material, or the like.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass".

(Barrier coating composition)
<Aqueous polyurethane resin>
Takelac WPB-341 (solid content 30%, glass transition temperature 115 ° C., manufactured by Mitsui Chemicals, Inc.)
<Highly polar resin having silanol groups>
Kuraray Poval R-1130 (average degree of polymerization 1700, degree of saponification 98.0-99.0%, silanol group content 0.3 mol%)
<Highly polar resin having no silanol group>
Exeval RS-2117 (average degree of polymerization 1700, degree of saponification 97.5-99.0%, manufactured by Kuraray Co., Ltd.)
Gosenol NH-18 (average degree of polymerization 1800, degree of saponification 98.0 to 99.0%, manufactured by Nippon Synthetic Chemical Co., Ltd.)
<Silane coupling agent>
KBM-403 (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)
<Solvent>
ion exchange water isopropyl alcohol

<Preparation of R-1130 aqueous solution>
10 parts by mass of Kuraray Poval R-1130 was added to 90 parts by mass of purified water, and the mixture was stirred at 95° C. for about 2 hours to obtain an aqueous solution of R-1130 (solid content: 10%).

<Preparation of RS-2117 aqueous solution>
10 parts by mass of Exeval RS-2117 was added to 90 parts by mass of purified water, and the mixture was stirred at 95° C. for about 2 hours to obtain an aqueous solution of RS-2117 (solid content: 10%).

<Adjustment of NH-18 aqueous solution>
10 parts by mass of Gohsenol NH-18 was added to 90 parts by mass of purified water, and the mixture was stirred at 95° C. for about 2 hours to obtain an aqueous NH-18 solution (solid content: 10%).

<Preparation of silica-deposited PET>
An isocyanate compound (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and saturated polyester (“Vylon 300” manufactured by Toyobo Co., Ltd.) are blended in a 1:1 mass ratio on one side of a PET film (E5100, thickness 12 μm, manufactured by Toyobo). The resulting mixture was applied and dried to form an adhesive layer having a thickness of 0.1 μm. Then, silica was vaporized by heating under a vacuum of 1×10 ⁻⁵ Torr using a vacuum vapor deposition apparatus to form a silica vapor deposition layer having a thickness of 20 nm on the adhesive layer to obtain silica vapor deposition PET.

<Preparation of alumina-deposited PET>
An isocyanate compound (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and saturated polyester (“Vylon 300” manufactured by Toyobo Co., Ltd.) are blended in a 1:1 mass ratio on one side of a PET film (E5100, thickness 12 μm, manufactured by Toyobo). The resulting mixture was applied and dried to form an adhesive layer having a thickness of 0.1 μm. Then, aluminum is evaporated using a vacuum deposition device, oxygen gas is supplied using a gas flow controller, deposition is performed at 1×10 ⁻⁴ Torr, and an alumina deposition layer having a thickness of 20 nm is formed on the adhesive layer. formed to obtain alumina-deposited PET.

(Example 1)
While stirring 22.2 parts by mass of Takelac WPB-341, 28.5 parts by mass of R-1130 aqueous solution with a solid content of 10%, 30.2 parts by mass of ion-exchanged water, and 18.1 parts by mass of isopropyl alcohol were added. After that, 1.0 part by mass of KBM-403 was further added, and the mixture was sufficiently stirred and mixed at room temperature to obtain a coating composition 1.
Coating composition 1 was applied onto the silica deposition layer surface of the silica deposition PET prepared above. It was applied with a 6-wire bar, dried with a drier, and then aged at 60° C. for one day.
A polyurethane adhesive (Takelac A515/Takenate A50, solid content 30%, manufactured by Mitsui Chemicals, Inc.) was applied on the obtained coat layer (coating amount after drying: 0.8 g/m ² ). It was coated with a 4-wire bar, laminated with a sealant film (RXC-22, thickness 60 μm, manufactured by Mitsui Chemicals Tohcello), and aged at 40° C. for 3 days to obtain a composite film.

(Example 2)
A composite film was obtained in the same manner as in Example 1, except that the substrate film was changed to the alumina-deposited PET prepared above.

(Comparative Examples 1 to 3)
Coating compositions 2 to 4 were prepared according to the formulations shown in Table 1, and composite films were obtained in the same manner as in Example 1.

(Comparative Examples 4-5)
Composite films were obtained in the same manner as in Examples 1 and 2, except that the coating composition was not used.

〔evaluation〕
<Laminate strength measurement (N/15 mm)>
(1) Normal conditions (dry conditions)
Each composite film of Examples 1-2 and Comparative Examples 1-5 was cut to a width of 15 mm.
The T-type peel strength was measured using a peel tester (manufactured by Yasuda Seiki Co., Ltd.) under the condition of a peel speed of 300 mm/min. The results are shown in Table 2.
(Boil condition)
Laminate strength was measured in the same manner as in dry conditions, except that each of the composite films of Examples 1-2 and Comparative Examples 1-5 was immersed in hot water at 90° C. for 30 minutes and then cut to a width of 15 mm. The results are shown in Table 2.
(Retort condition)
The composite films of Examples 1-2 and Comparative Examples 1-5 were immersed in hot water at 120° C. and 2 atm for 30 minutes, and then cut into 15 mm wide laminates in the same manner as in the dry conditions. Strength was measured. The results are shown in Table 2.
(2) Watering conditions (dry conditions)
Each composite film of Examples 1-2 and Comparative Examples 1-5 was cut to a width of 15 mm.
The laminate strength was measured using a peel tester (manufactured by Yasuda Seiki Co., Ltd.) at a peel rate of 300 mm/min while applying absorbent cotton soaked with water to the peel surface of each sample piece. The results are shown in Table 2.
(Boil condition)
Laminate strength was measured in the same manner as in dry conditions, except that each composite film of Examples 1-2 and Comparative Examples 1-5 was immersed in hot water at 90° C. for 30 minutes and then cut into 15 mm widths. The results are shown in Table 2.
(Retort condition)
The composite films of Examples 1-2 and Comparative Examples 1-5 were immersed in hot water at 120° C. and 2 atm for 30 minutes, and then cut into 15 mm widths. Lamination was performed in the same manner as in dry conditions. Strength was measured. The results are shown in Table 2.
In Table 2, the number with F means that the composite film was broken without peeling at the strength of the number. Moreover, what is described as "occurrence of floating" in Table 2 means that peeling has occurred in the composite film.

<Seal strength (N/15mm)>
The composite films of Examples 1 and 2 and Comparative Examples 1 to 5 were made into bags using an impulse sealer (manufactured by Fuji Impulse Sealer Co., Ltd.), and a peel tester (manufactured by Yasuda Seiki Co., Ltd.) was used at a peel speed of 300 mm / min. The seal strength was measured under the conditions of The results are shown in Table 2.
In Table 2, the number with F means that the composite film was broken without peeling at the strength of the number.

<Oxygen permeability (cc/m ² /day/atm)>
After leaving the composite films (for oxygen permeability test) of Examples 1-2 and Comparative Examples 1-5 in an atmosphere of 25° C. and 90% RH for 72 hours, an oxygen permeability measuring device was used in accordance with JIS K7126 B method. (manufactured by Mocon, product name: OX-TRAN1/50) was used to measure the oxygen transmission rate (OTR value).
The measurement was performed at 25° C. in an atmosphere of 90% RH. The results are shown in Table 2.

<Water vapor transmission rate (g/m ² /day)>
The composite films (for water vapor transmission rate test) of Examples 1-2 and Comparative Examples 1-5 were measured for water vapor transmission rate (WVTR value) according to JIS Z0222 as follows.
For each of the composite films of Examples 1-2 and Comparative Examples 1-5, a bag having a size of 10 cm×10 cm was used to form a bag having the same volume, and 15 g of calcium chloride was filled therein and then heat-sealed. This bag was placed in a constant temperature and humidity apparatus at 40° C. and 90% RH, and the mass was measured every 5 days. The water vapor transmission rate was calculated from the slope of the regression line between the elapsed time after the third day and the mass of the bag. The results are shown in Table 2.

In Examples 1 and 2, in which composite films were produced using the barrier coating composition of the present invention, lamination strength, seal strength, water vapor barrier properties, and Both oxygen barrier properties were excellent.
On the other hand, in Comparative Example 1, in which a composite film was produced using Coating Composition 2 which does not contain a highly polar resin having a silanol group, the lamination strength was lowered under the wet conditions and the retort conditions. In addition, in Comparative Example 2 in which a composite film was produced using coating composition 3 which does not contain a highly polar resin having a silanol group, the lamination strength was inferior under wet conditions, and floating occurred under retort conditions. Comparative Example 3, in which a composite film was produced using Coating Composition 4 containing no highly polar resin, was inferior in oxygen barrier properties and water vapor barrier properties.
Moreover, in Comparative Examples 4 and 5 in which the composite films were produced without using the coating composition, they were inferior in any of lamination strength, seal strength, water vapor barrier property and oxygen barrier property.

Since the barrier coating composition of the present invention has the above-described constitution, it is not only excellent in lamination strength, seal strength, water vapor barrier property and oxygen barrier property under normal and wet conditions, but also lamination after high-temperature and high-pressure treatment. A composite film having excellent strength can be obtained.
In addition, the composite film of the present invention can be suitably used as a barrier film, packaging material, or the like, particularly as a medical barrier film, packaging material, or the like.

Claims (6)

Containing an aqueous polyurethane resin, a highly polar resin having a silanol group, and a silane coupling agent,
The mass ratio of the highly polar resin having a silanol group to 100 parts by mass of the aqueous polyurethane resin is 15 to 150 parts by mass,
The highly polar resin having a silanol group is silanol-modified polyvinyl alcohol
A barrier coating composition characterized by: 2. The barrier coating composition according to claim 1 , wherein the highly polar resin having silanol groups has an intramolecular silanol group content of 0.05 to 3 mol % as a monomer unit. 3. The barrier coating composition according to claim 1 , wherein the silane coupling agent is an epoxy group-containing silane coupling agent. 4. The barrier coating composition according to any one of claims 1 to 3 , which is used for laminates. A composite film comprising at least a substrate film, a vapor deposition layer and a coat layer in this order, wherein the coat layer is formed by applying the barrier coating composition according to any one of claims 1 to 4 . A composite film characterized by: 6. The composite film according to claim 5 , wherein the deposited layer is one or more deposited layers selected from the group consisting of silica and alumina.