WO2020195904A1

WO2020195904A1 - Barrier coating composition and composite film

Info

Publication number: WO2020195904A1
Application number: PCT/JP2020/010855
Authority: WO
Inventors: 田中　宏樹; 裕松岡
Original assignee: サカタインクス株式会社
Priority date: 2019-03-28
Filing date: 2020-03-12
Publication date: 2020-10-01
Also published as: JP7319800B2; JP2020164559A

Abstract

The present invention provides: a barrier coating composition capable of giving a composite film which exhibits not only excellent lamination strength, sealing strength, water vapor barrier properties and oxygen barrier properties under ordinary/water-attached conditions, but also excellent lamination strength following a treatment at high temperature and high pressure; and a composite film obtained using the barrier coating composition. The present invention relates to a barrier coating composition characterized by containing an aqueous polyurethane resin, a silanol group-containing highly polar resin and a silane coupling agent.

Description

Barrier coating composition and composite film

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

In the field of packaging bags used for food packaging, packaging bags that have a function of hot water treatment and can easily cook the contents of each bag are often manufactured.
The packaging bag for hot water treatment has a high bactericidal effect and the packaging bag is completely sealed, so that the contents are less likely to spoil, and is an effective means for long-term storage. However, if the gas barrier property is not sufficient, oxygen will enter the packaging bag during storage, causing deterioration and deterioration of the contents. Therefore, in the packaging bag for hot water treatment, how the permeation of oxygen and the like can be suppressed is a major factor in determining the value of the packaging bag.

Conventionally, in packaging bags used for packaging applications such as foods and medical treatments, a method of providing various gas barrier layers has been considered in order to block gases such as oxygen and water vapor. In particular, metals and metal oxides that have been used as materials having high gas barrier properties are laminated on a printing base film or the like by a vapor deposition method. As for the above-mentioned packaging bag for hot water treatment, a packaging bag for hot water treatment in which an aluminum vapor deposition film or a foil of aluminum itself is laminated is mainly used for long-term storage. However, composite laminated films using these materials are generally expensive. It also has the 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 vapor deposition 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 the 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 a 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 lamination strength. In the field of packaging bags used for packaging applications such as food and medical care, in addition to excellent gas barrier properties, it is required to have excellent lamination strength not only under normal (dry) conditions but also under watering conditions. ing.
Further, in the medical field, there is a demand for a product having extremely excellent lamination strength that can withstand sterilization treatment at high temperature and high pressure.

Japanese Unexamined Patent Publication No. 2012-020433 Japanese Unexamined Patent Publication No. 2017-222151

Therefore, an object of the present invention is to obtain a composite film which is not only excellent in laminate strength, seal strength, water vapor barrier property and oxygen barrier property under normal and watering conditions, but also excellent in laminate strength even after high temperature and high pressure treatment. It is to provide a barrier coating composition which can be made, and to provide a composite film obtained by using the barrier coating composition.

As a result of repeated studies, the present inventors have applied 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. Since it has excellent cohesiveness of the coating film and extremely excellent adhesion to the vapor-deposited film made of metal oxide, etc., it not only has excellent lamination strength, seal strength, water vapor barrier property and oxygen barrier property under normal and watering conditions. The present invention has been completed by finding that a composite film having excellent lamination strength can be obtained even after high-temperature and high-pressure treatment.

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.
The highly polar resin having a silanol group preferably has a silanol group content in the molecule of 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 laminating.
Further, the present invention is a composite film having at least a base film, a vapor-deposited layer, and a coat layer in this order, and the coat 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 vapor deposition layer is preferably one or more types of vapor deposition layers selected from the group consisting of silica and alumina.
Hereinafter, the barrier coating composition and the composite film will be described in detail.

[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 aqueous polyurethane resin preferably contains an acid group-containing polyurethane resin and a polyamine compound from the viewpoint of preferably exhibiting gas barrier properties such as water vapor barrier properties and oxygen barrier properties.
The aqueous polyurethane resin may be a mixture of the acid group-containing polyurethane resin and the polyamine compound, or may be a copolymer.
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) and is shared. It may be a bond (eg, an amide bond, etc.).

The acid group of the acid group-containing polyurethane resin may be any as long as it can be bonded to the amino group (primary amino group, secondary amino group, tertiary amino group, etc.) of the polyamine compound, for example, a carboxyl group. , Sulfonic acid group and the like. The acid group can usually be neutralized with a neutralizing agent (base), and may form a salt with the base.
The acid group may be located at the end of the acid group-containing polyurethane resin or in the 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 preferably expressing gas barrier properties and water resistance. It is more preferably 15 to 60 mgKOH / g.
In addition, in this specification, the acid value means the acid value measured by the method according to JIS K 0070.

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, preferably 20 to 60% by mass, from the viewpoint of preferably expressing gas barrier properties. Is more preferable.
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 constituent unit of the polyurethane resin. Means.
When two or more kinds of mixtures are used as the acid group-containing polyurethane resin, the urethane group concentration and the urea group concentration can be calculated based on the preparation base of the reaction component, that is, the usage ratio of each component.

The acid group-containing polyurethane resin usually has at least a rigid unit (a unit composed of a hydrocarbon ring) and a short chain unit (for example, a unit composed of a hydrocarbon chain). That is, the constituent unit of the acid group-containing polyurethane resin is usually derived from a polyisocyanate component, a polyhydroxyic acid component, a polyol component or a chain extender component (particularly, at least a polyisocyanate component), and is a hydrocarbon ring (aromatic). And at least one of the non-aromatic hydrocarbon rings). The ratio of the unit composed of the hydrocarbon ring to the structural unit of the acid group-containing polyurethane resin is 10 to 70% by mass with respect to the total of all the structural units from the viewpoint of preferably expressing the gas barrier property and the laminate strength. It is preferable, it is more preferably 15 to 65% by mass, and further 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 800 to 100,000. It is 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 property of the coat layer can be preferably imparted.
In the present specification, the number average molecular weight is a standard polystyrene-equivalent value measured by gel permeation chromatography (GPC).

The acid group-containing polyurethane resin may be crystalline in order to enhance the gas barrier property.
The glass transition temperature (Tg) of the acid group-containing polyurethane resin is preferably 100 to 200 ° C., more preferably 110 to 180 ° C., and even more preferably 115 to 150 ° C. from the viewpoint of preferably exhibiting gas barrier properties.
In the present specification, the 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 be bonded to the acid group of the acid group-containing polyurethane resin, and is, for example, an amino group such as a primary amino group, a secondary amino group, or a tertiary amino group. Examples include nitrogen atoms.
The polyamine compound is not particularly limited as long as it can bond with the acid group of the acid group-containing polyurethane resin and improve the gas barrier property, 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 at least one amino group selected from the group consisting of a primary amino group, a secondary amino group and a tertiary amino group is preferable.

Specific examples of the polyamine compound include alkylenediamines, polyalkylene polyamines, and silicon compounds having a plurality of basic nitrogen atoms. 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. Can be mentioned. Examples of the polyalkylene polyamines include tetraalkylene polyamines. 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 and 3- [N- (2). -Aminoethyl) Amino] A silane coupling agent having a plurality of basic nitrogen atoms such as propyltriethoxysilane and the like can be mentioned.
The silane coupling agent corresponding to the polyamine compound shall 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, and more preferably 200 to 1900 mgKOH from the viewpoint of preferably expressing gas barrier properties and the water dispersion stability of the aqueous polyurethane resin. / G is more preferable, 200 to 1700 mgKOH / g is particularly preferable, and 300 to 1500 mgKOH / g is most preferable. The amine value of the polyamine compound is measured by the following method.
[Measuring method of amine value]
Weigh 0.5 to 2 g of the sample (sample amount Sg). Add 30 g of ethanol to the precisely weighed sample and dissolve. Bromophenol blue is added to the obtained solution as an indicator, and titration is performed with a 0.2 mol / L ethanolic hydrochloric acid solution (titer f). Using the titration amount (AmL) at this time as the end point at the point where the color of the solution changes from green to yellow, the amine titer is calculated using the following formula 1.
Calculation formula 1: Amine value = A × f × 0.2 × 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 to the basic nitrogen atom of the polyamine compound is 10/1. An amount of about 0.1 / 1 is preferable, and an amount of 5/1 to 0.2 / 1 is more preferable. When the acid group / basic nitrogen atom is in the above range, the cross-linking 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 being dispersed in an aqueous medium (aqueous dispersion).
Examples of the aqueous medium include water, a water-soluble or hydrophilic organic solvent, or a mixture 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; carbitols; nitriles such as acetonitrile. And so on.
As the aqueous medium, water or one 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 group of the acid group-containing polyurethane resin. Usually contains a neutralizer.

In the aqueous dispersion of the aqueous polyurethane resin, the average particle size of the dispersed particles (polyurethane resin particles) is not particularly limited, but the uniform dispersibility between the dispersed particles and other materials and the dispersion stability of the barrier coating composition From the viewpoint of ensuring the above and preferably expressing the gas barrier property, 20 nm to 500 nm is preferable, 25 nm to 300 nm is more preferable, and 30 nm to 200 nm is further preferable.
In this specification, the average particle size is measured by a concentrated particle size analyzer (FPAR-10 manufactured by Otsuka Electronics Co., Ltd.) with a solid content concentration of 0.03 to 0.3% by mass (diluted with water). It is a value measured by.

As the aqueous polyurethane resin, a commercially available one may be used, or one manufactured by a known production method may be used.
The method for producing the aqueous polyurethane resin is not particularly limited, and ordinary polyurethane resin aqueous techniques such as the acetone method and the prepolymer method are used. In the urethanization reaction, a urethanization catalyst such as an amine-based catalyst, a tin-based catalyst, or a lead-based catalyst may be used, if 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 polyhydroxyic 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 them. More specifically, in an inert organic solvent (particularly, a hydrophilic or water-soluble organic solvent), a polyisocyanate compound, a polyhydroxyic acid, and a polyol component are reacted to have a pre-isocyanate group at the terminal. A polymer is produced, neutralized with a neutralizing agent, dissolved or dispersed in an aqueous medium, and then a chain extender component is added and reacted to remove an organic solvent, whereby the aqueous acid group-containing polyurethane resin is aqueous. Dispersions can be prepared.
The 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 as necessary.
When heating, the heating temperature is preferably 30 to 60 ° C.

The barrier coating composition of the present invention contains a highly polar resin having a silanol group.
The high-polarity resin having a silanol group not only has excellent bondability with a silane coupling agent described later, but can also provide a large number of connection points with a vapor deposition layer described later, so that the coating composition of the present invention can be used. Since the coating film has excellent cohesive force and extremely excellent adhesion to the vapor deposition layer, it not only has excellent lamination strength, sealing strength, water vapor barrier property and oxygen barrier property under normal and watering conditions, but also after high-temperature and high-pressure treatment. It is also possible to obtain a composite film having excellent lamination strength.
Here, the "high temperature and high pressure treatment" means a treatment of immersing in hot water at 120 ° C. and 2 atm for 30 minutes, and the composite film using the barrier coating composition of the present invention is the above-mentioned "high temperature and high pressure treatment". Excellent laminate strength even after "treatment".

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 group include an amino group, an ester group, a carboxyl group, a sulfone group, a cyano group, a thiol group, and a hydroxyl group.
Of these, a hydroxyl group and a carboxyl group are preferable, and a hydroxyl group is more preferable, from the viewpoint of preferably expressing gas barrier properties.
Such a highly polar resin has excellent solubility in a solvent such as water, and also has excellent compatibility with the above-mentioned aqueous dispersion of the aqueous polyurethane resin. Therefore, a coat layer having excellent adhesion to a vapor deposition layer described later. Can be obtained.

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

As for the highly polar resin having a silanol group, the highly polar resin having a silanol group 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 in the above range, the solubility in water and alcohol can be improved.
The highly polar resin having a silanol group is more preferably 0.1 to 2.0 mol%.

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

The high-polarity resin having a silanol group preferably has a saponification degree of 90 to 100%, more preferably 95 to 100%, and even more preferably 97 to 100%.

The high-polarity resin having a silanol group preferably has an average degree of polymerization of 200 to 3000, and more preferably 400 to 2000.
By setting the average degree of polymerization within the range, the viscosity of the coating composition does not increase too much, it is easy to mix uniformly with other components, and the gas barrier property of the coat layer and the peel strength from other layers are achieved. Can be preferably applied.

As the highly polar resin having a silanol group, a commercially available one may be used, or a resin satisfying the silanol group content, saponification degree, average degree of polymerization and the like may be produced by a known production method.
Examples of commercially available high-polarity resins having a silanol group include R-1130, R-2105, and R-2130 (all manufactured by Kuraray Co., Ltd.).

The total content of the aqueous polyurethane resin and the high-polarity resin having a silanol group is preferably 0.5 to 30 parts by mass in terms of solid content with respect to 100 parts by mass of the barrier coating composition of the present invention. More preferably, it is 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, and more preferably 20 to 100 parts by mass. ..
Within the above range, both water resistance and gas barrier property can be suitably compatible.

Examples of the silane coupling agent include compounds represented by RSiX ₃ (where R is an organic reactive group and X is an alkoxy group).
Examples of the organic reactive group include those having an amino group, a (meth) acrylic group, an epoxy group, a vinyl group, a mercapto group, an isocyanate group, an isocyanurate group and the like.
In addition, in this specification, a (meth) acrylic group indicates both an acrylic group and a methacrylic group.
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, and (meth) acrylic. Examples thereof 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 the above epoxy group, 2 (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxy Examples thereof include propylmethyldimethoxysilane and 3-glycidoxypropylethyldiethoxysilane. 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) acrylic group include 3-acryloxypropyltrimethoxysilane. Examples of the silane coupling agent having an isocyanate group include 3-isocyanatepropyltriethoxysilane. Examples of the silane coupling agent having an 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. Of these, 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 aqueous polyurethane resin and the highly polar resin having a silanol group, and further has excellent reactivity with the vapor deposition layer described later. , Lamination strength and gas barrier property can be suitably improved.

The amount of 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, either an aqueous solvent or a non-aqueous solvent can be used as long as it can dissolve the aqueous polyurethane resin, the high 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. Alcohol can be mentioned, 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, based on 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 and kaolin, colloidal silica, surfactant and the like, which are generally known as antiblocking agents. It may be blended.

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

[Manufacturing method of barrier coating composition]
The method for producing the barrier coating composition of the present invention is not particularly limited, and for example, the solvent is added to the aqueous polyurethane resin, the high polar resin having a silanol group, and the silane coupling agent. A coating liquid having a predetermined concentration can be prepared by sufficiently stirring and mixing at room temperature.
When the above silane coupling agent is added, if it is added all at once, it may aggregate, so it is preferable to add the silane coupling agent while stirring slowly.

[Composite film]
A composite film having at least a base film, a vapor-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 inventions.

The base film is not particularly limited as long as it is formed of a thermoplastic resin or the like having a transparent film-forming ability.
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, and the like. Polyethylene-based resins such as ethylene-vinyl acetate copolymer, ethylene-methylmethacrylate copolymer, and ionomer resin; polyester-based resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; nylon-6, nylon-6,6, Metaxylene diamine-adipic acid reduced polymer, amide resin such as polymethylmethacrylimide, acrylic resin such as polymethylmethacrylate; polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, polyacrylonitrile, etc. Styrene, acrylonitrile-based resins; hydrophobic cellulose-based resins such as cellulose triacetate and cellulose diacetate; halogen-containing resins such as polyvinyl chloride, polyvinylidene chloride, vinylidene fluoride, and 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, polyether sulfone resins, polyether ether ketone resins, polyphenylene oxide resins, polymethylene oxide resins, and liquid crystal resins. And so on. These may be used alone or in combination of two or more.
It is preferable that the base film is subjected to surface treatment such as plasma treatment or corona discharge treatment on the side where the vapor deposition layer and the coat layer are provided.

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

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

The thickness of the vapor-deposited 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 barrier coating composition is not particularly limited, but a roll coating method using a 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 the like. A coating method or the like combining these methods can be used.

The thickness of the coat 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 a high gas barrier property, and if it exceeds 5 μm, no significant improvement in the gas barrier property may be observed.

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

Examples of the organic solvent-type printing ink composition include an aromatic / non-aromatic mixed organic solvent-based printing ink composition containing a pigment and a polyurethane resin, as well as Japanese Patent Application Laid-Open No. 01-261476 (pigment, polyurethane resin). , Aromatic / non-aromatic mixed organic solvent-based printing ink composition containing chlorinated polypropylene), Japanese Patent Publication No. 07-113098 (non-aromatic organic solvent-based printing ink composition containing pigment and polyurethane resin), Examples thereof include organic solvent-based printing ink compositions disclosed in Japanese Patent Application Laid-Open No. 07-324179 (pigments, polyurethane resins, non-aromatic / non-ketone organic solvent-based printing ink compositions).

Examples of the water-based printing ink composition include JP-A-06-155649 (water-based printing ink composition containing a pigment, an acrylic binder resin, and a hydrazine-based cross-linking agent) and JP-A-06-206972 (pigment, water). , Aqueous printing ink composition containing a polyurethane-based binder resin) and the like.

Recently, as environment-friendly inks, water-based printing ink compositions and organic solvent-based printing ink compositions that do not use aromatic and ketone-based organic solvents as much as possible have been used. However, these can be preferably used.
Further, 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, and a sealant layer.

The adhesive layer is preferably formed between the base film and the vapor-deposited layer, between the coat layer and the sealant layer, and the like.
As the adhesive layer, an adhesive composition conventionally used for producing a composite laminated film for packaging can be appropriately selected and formed by using various coating means.
Examples of the adhesive composition include various adhesives such as urethane type, polyester type and acrylic type, and various adhesives such as titanium type, isocyanate type, imine type and polybutadiene type.

The sealant layer is a heat-sealing sheet material conventionally used in 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 cooling them into a film.

[Manufacturing method of composite film]
The method for producing the composite film of the present invention is not particularly limited, and a conventional method can be appropriately selected and used.
For example, the following methods (a) to (d) can be mentioned.
(A) A vapor-deposited layer is formed on a base film (the base film may be a laminated film having a vapor-deposited layer) by the method described above, and then the barrier coating composition and the adhesive composition are sequentially applied. A method of obtaining a composite film by laminating a sealant layer after the work.
(B) After forming a vapor-deposited layer on a base film (the base film may be a laminated film having a vapor-deposited layer) by the above-mentioned method, the above-mentioned adhesive composition, barrier coating composition, and adhesive. A method of obtaining a composite film by sequentially coating the compositions and then laminating a sealant layer.
(C) A vapor-deposited layer was formed on a base film (the base film may be a laminated film having a vapor-deposited layer) by the method described above, and then an ink composition was first printed to form a printed layer. After that, a method of obtaining a composite film by sequentially coating the above-mentioned adhesive composition, barrier coating composition, and adhesive composition, and then laminating a sealant layer.
(D) After forming a vapor-deposited layer on a base film (the base film may be a laminated film having a vapor-deposited layer) by the above-mentioned method, the above-mentioned adhesive composition, barrier coating composition, and adhesive. A method of obtaining a barrier composite film by sequentially coating the compositions, printing the ink composition to form a print layer, and further laminating a sealant layer.

Regarding the coating method of the above adhesive composition, a roll coating method using a normal 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. A coating method or the like that combines the above methods can be used.
Further, in order to form the print layer, a gravure printing method or a flexographic printing method can usually be 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 film thickness of the adhesive layer is thinner than 2 μm, the adhesiveness between the coat layer and the other layer may decrease, while if it is thicker than 3 μm, the adhesiveness does not increase in proportion to the increase in the film thickness. Further, when the composite film is used as a packaging bag, good handleability may not be obtained.
If a coating film having a film thickness within the above range cannot be obtained by one coating, it is possible to perform a large number of coatings.

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

Since the barrier coating composition of the present invention has the above-mentioned structure, it is possible to obtain a composite film having excellent lamination strength, sealing strength, water vapor barrier property and oxygen barrier property under boiling conditions and watering conditions.
In addition, the composite film of the present invention can be suitably used as a barrier film, a packaging material, or the like.

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 "part" means "part by mass".

(Barrier coating composition)
<Aqueous polyurethane resin>
Takelac WPB-341 (solid content 30%, glass transition temperature 115 ° C, manufactured by Mitsui Chemicals, Inc.)
<High-polarity resin with silanol group>
Kuraray Povar R-1130 (average degree of polymerization 1700, saponification degree 98.0-99.0%, silanol group content 0.3 mol%)
<High-polarity resin without silanol group>
Excelval RS-2117 (average degree of polymerization 1700, saponification degree 97.5-99.0%, manufactured by Kuraray)
Gosenol NH-18 (average degree of polymerization 1800, saponification degree 98.0-99.0%, manufactured by Japan Synthetic Chemical Co., Ltd.)
<Silane coupling agent>
KBM-403 (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)
<Solvent>
Ion-exchanged 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 Excelval 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 RS-2117 solution (solid content: 10%).

<Adjustment of NH-18 aqueous solution>
10 parts by mass of Gosenol 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%).

<Making silica-film-deposited PET>
Isocyanate compound ("Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd.) and saturated polyester ("Byron 300" manufactured by Toyobo Co., Ltd.) are mixed on one side surface of PET film (E5100, thickness 12 μm, manufactured by Toyobo Co., Ltd.) in a 1: 1 mass ratio. The mixture was applied and dried to form an adhesive layer having a thickness of 0.1 μm. Next, silica was evaporated by a heating method 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.

<Making alumina-deposited PET>
Isocyanate compound ("Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd.) and saturated polyester ("Byron 300" manufactured by Toyobo Co., Ltd.) are mixed on one side surface of PET film (E5100, thickness 12 μm, manufactured by Toyobo Co., Ltd.) in a 1: 1 mass ratio. The mixture was applied and dried to form an adhesive layer having a thickness of 0.1 μm. Next, aluminum is evaporated using a vacuum vapor deposition device, oxygen gas is supplied using a gas flow control device, vapor deposition is performed at 1 × 10 ^-4 Torr, and an alumina vapor deposition layer having a thickness of 20 nm is formed on the adhesive layer. It was formed to obtain an alumina-deposited PET.

(Example 1)
While stirring 22.2 parts by mass of Takelac WPB-341, 28.5 parts by mass of an aqueous solution of R-1130 having 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.
On the silica-deposited layer surface of the silica-deposited PET produced above, coating composition 1 was added to No. 6 The coating was applied with a wire bar, dried with a dryer, and then aged at 60 ° C. for 1 day.
A polyurethane adhesive (Takelac A515 / Takenate A50, solid content 30%, manufactured by Mitsui Chemicals, Inc.) was applied onto the obtained coat layer (coating amount after drying 0.8 g / m ² ). It was coated with a 4-wire bar, a sealant film (RXC-22, thickness 60 μm, manufactured by Mitsui Chemicals Tohcello Co., Ltd.) was laminated, and aged at 40 ° C. for 3 days to obtain a composite film.

(Example 2)
In Example 1, a composite film was obtained by the same method except that the base film was changed to the alumina-deposited PET produced above.

(Comparative Examples 1 to 3)
The coating compositions 2 to 4 were adjusted according to the formulation shown in Table 1, and a composite film was obtained in the same manner as in Example 1.

(Comparative Examples 4 to 5)
In Examples 1 and 2, a composite film was obtained by the same method 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 and 2 and Comparative Examples 1 to 5 was cut into 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)
The laminate strength was measured by the same method as in the dry condition except that the composite films of Examples 1 and 2 and Comparative Examples 1 to 5 were immersed in hot water at 90 ° C. for 30 minutes and then cut into a width of 15 mm. The results are shown in Table 2.
(Retort condition)
Laminated by the same method as in dry conditions, except that the composite films of Examples 1 and 2 and Comparative Examples 1 to 5 were immersed in hot water at 120 ° C. and 2 atm for 30 minutes and then cut to a width of 15 mm. The intensity was measured. The results are shown in Table 2.
(2) Watering conditions (dry conditions)
Each composite film of Examples 1 and 2 and Comparative Examples 1 to 5 was cut into a width of 15 mm.
While applying cotton wool soaked in water to the peeling surface of each sample piece, the T-type peel strength was measured using a peeling tester (manufactured by Yasuda Seiki Co., Ltd.) under the condition of a peeling speed of 300 mm / min. The results are shown in Table 2.
(Boil condition)
The laminate strength was measured by the same method as in the dry condition except that the composite films of Examples 1 and 2 and Comparative Examples 1 to 5 were immersed in hot water at 90 ° C. for 30 minutes and then cut into a width of 15 mm. The results are shown in Table 2.
(Retort condition)
Laminated by the same method as in dry conditions, except that the composite films of Examples 1 and 2 and Comparative Examples 1 to 5 were immersed in hot water at 120 ° C. and 2 atm for 30 minutes and then cut to a width of 15 mm. The intensity was measured. The results are shown in Table 2.
In addition, when F is attached to the number in Table 2, it means that the composite film was broken without peeling at the strength of the number. In addition, what is described as "floating" in Table 2 means that the composite film is peeled off.

<Seal strength (N / 15mm)>
Each of the composite films of Examples 1 and 2 and Comparative Examples 1 to 5 is made into a bag using an impulse sealer (manufactured by Fuji Impulse Sheila), and a peeling tester (manufactured by Yasuda Seiki Co., Ltd.) is used to peel off at a speed of 300 mm / min. The seal strength was measured under the conditions of. The results are shown in Table 2.
In addition, when F is attached to the number in Table 2, it 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 and 2 and Comparative Examples 1 to 5 in an atmosphere of 25 ° C. and 90% RH for 72 hours, an oxygen permeability measuring device according to the JIS K7126 B method. (Manufactured by Mocon, product name: OX-TRAN1 / 50) was used to measure the oxygen permeability (OTR value).
The measurement was carried out at 25 ° C. in an atmosphere of 90% RH. The results are shown in Table 2.

<Water vapor permeability (g / m ² / day)>
The water vapor transmittance (WVTR value) of the composite films of Examples 1 and 2 and Comparative Examples 1 to 5 (for the water vapor transmittance test) was measured according to JIS Z0222 as follows.
Each of the composite films of Examples 1 and 2 and Comparative Examples 1 to 5 was made into bags having the same volume using those having a size of 10 cm × 10 cm, packed with 15 g of calcium chloride, and then sealed. The bag was placed in a constant temperature and humidity device at 40 ° C. and 90% RH, and the mass was measured every 5 days. The water vapor transmittance was calculated from the slope of the regression line between the elapsed time after the third day and the bag mass. The results are shown in Table 2.

In Examples 1 and 2 in which a composite film was prepared using the barrier coating composition of the present invention, the lamination strength, the seal strength, the water vapor barrier property and the dry conditions under the normal conditions and the watering conditions, the boiling conditions and the retort conditions were obtained. It was excellent in all of the oxygen barrier properties.
On the other hand, in Comparative Example 1 in which a composite film was prepared using the coating composition 2 containing no highly polar resin having a silanol group, the lamination strength was lowered under the watering condition and the retort condition. Further, in Comparative Example 2 in which a composite film was prepared using the coating composition 3 containing no highly polar resin having a silanol group, the lamination strength was inferior under the watering condition, and floating occurred under the retort condition. Comparative Example 3 in which a composite film was prepared using the coating composition 4 containing no highly polar resin was inferior in oxygen barrier property and water vapor barrier property.
Further, in Comparative Examples 4 and 5 in which the composite film was prepared without using the coating composition, any of the laminate strength, the seal strength, the water vapor barrier property and the oxygen barrier property was inferior.

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

Claims

A barrier coating composition containing an aqueous polyurethane resin, a highly polar resin having a silanol group, and a silane coupling agent.
The barrier coating composition according to claim 1, wherein 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 barrier coating composition according to claim 1 or 2, wherein the highly polar resin having a silanol group has an intramolecular silanol group content of 0.05 to 3 mol% as a monomer unit.
The barrier coating composition according to any one of claims 1 to 3, wherein the silane coupling agent is a silane coupling agent having an epoxy group.
The barrier coating composition according to any one of claims 1 to 4, which is for laminating.
A composite film having at least a base film, a vapor-deposited layer, and a coat layer in this order, and the coat layer was formed by applying the barrier coating composition according to any one of claims 1 to 5. A composite film characterized by being a thing.
The composite film according to claim 6, wherein the thin-film deposition layer is one or more types of thin-film deposition layers selected from the group consisting of silica and alumina.