WO2019159786A1

WO2019159786A1 - Barrier coating composition and composite film

Info

Publication number: WO2019159786A1
Application number: PCT/JP2019/004226
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: 2018-02-16
Filing date: 2019-02-06
Publication date: 2019-08-22
Also published as: JP2019143000A; JP7113628B2; CN111712553A

Abstract

Provided is a barrier coating composition that can produce a composite film that exhibits an excellent lamination strength under boiling conditions and water-attachment conditions and exhibits an excellent seal strength, water vapor barrier performance, and oxygen barrier performance. Also provided is a composite film obtained using this barrier coating composition. The invention relates to a barrier coating composition that characterized by containing a water-based polyurethane resin, a high-polarity resin having an ethylene chain, 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 coating layer formed using the barrier coating composition.

In the field of packaging bags used for food packaging applications, packaging bags that have a function of performing hot water treatment and can easily cook the contents of each bag are often manufactured.
The packaging bag for hot water treatment is an effective means for long-term storage in that the sterilization effect is high and the packaging bag is completely sealed, so that the contents are not easily spoiled. However, if the gas barrier property is not sufficient, oxygen enters the packaging bag during storage, and the contents are deteriorated and deteriorated. Therefore, how to suppress permeation of oxygen or the like in the hot water treatment packaging bag is a major factor that determines the value of the packaging bag.

2. Description of the Related Art Conventionally, in packaging bags used for packaging applications such as food and medicine, various gas barrier layers have been considered in order to block gases such as oxygen and water vapor. In particular, metals and metal oxides that have been laminated on a printing substrate film or the like by a vapor deposition method have been used as materials having high gas barrier properties. And also in the said hot water treatment packaging bag, the hot water treatment packaging bag which laminated | stacked the aluminum vapor deposition film and the foil of aluminum itself has become the mainstream for long-term preservation | save. However, the composite laminate film using these materials is generally expensive. Moreover, it has a problem that it cannot be used in a field where transparency is required.

In recent years, utilization 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 whose 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-based resin and polyvinyl alcohol has been proposed (for example, see Patent Document 2).

A gas barrier film having a laminated structure requires not only excellent gas barrier properties but also excellent laminate strength. In particular, in the field of packaging bags used for packaging applications such as food and medicine, in addition to excellent gas barrier properties, not only laminate strength in dry conditions but also excellent laminate strength in watering conditions. It has come to be required.

JP 2012-020433 A JP 2017-222151 A

Then, the subject of this invention is providing the barrier coating composition which can obtain the composite film excellent in the laminate strength in a boil condition and watering conditions, seal strength, water vapor | steam barrier property, and oxygen barrier property, and It is to provide a composite film obtained using the barrier coating composition.

As a result of repeated research, the present inventors have applied a coating composition containing an aqueous polyurethane resin, a highly polar resin having an ethylene chain, and a silane coupling agent. Because it has excellent cohesiveness of the coating film and adhesion to the vapor-deposited film made of metal oxide, a composite film excellent in laminate strength, seal strength, water vapor barrier property and oxygen barrier property under boil conditions and watering conditions is obtained. The present invention has been found out and the present invention has been completed.

That is, the barrier coating composition of the present invention comprises an aqueous polyurethane resin, a highly polar resin having an ethylene chain, and a silane coupling agent.

In the barrier coating composition of the present invention, the mass ratio of the high polarity resin having an ethylene chain to 100 parts by mass of the aqueous polyurethane resin is preferably 15 to 150 parts by mass.
The high polarity resin having an ethylene chain preferably has an ethylene chain ratio of 0.5 to 30 mol%.
The highly polar resin having an ethylene chain preferably has an ethylene chain in the main chain.
The silane coupling agent is preferably a silane coupling agent having an epoxy group.
The barrier coating composition of the present invention is preferably used for laminating.
Moreover, this invention is a composite film which has a base film, a vapor deposition layer, and a coating layer in this order, Comprising: The said coating layer shall be formed by apply | coating the said 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 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 an ethylene chain, 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 suitably expressing gas 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). It may be a bond (for example, an amide bond).

The acid group of the acid group-containing polyurethane resin is not limited 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. And sulfonic acid groups. 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 or the side chain of the acid group-containing polyurethane resin, 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 favorably developing gas barrier properties and water resistance. More preferably, it is 15 to 60 mg KOH / 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, and preferably 20 to 60% by mass from the viewpoint of suitably exhibiting 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 structural 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 charged base of the reaction component, that is, the use ratio of each component.

The acid group-containing polyurethane resin usually has at least rigid units (units composed of hydrocarbon rings) and short chain units (for example, units composed of hydrocarbon chains). That is, the structural unit of the acid group-containing polyurethane resin is usually derived from a polyisocyanate component, a polyhydroxy acid component, a polyol component or a chain extender component (especially at least a polyisocyanate component), and a hydrocarbon ring (aromatic And at least one of non-aromatic hydrocarbon rings). The proportion of units composed of hydrocarbon rings in the structural units 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 suitably expressing gas barrier properties and laminate strength. It is preferably 15 to 65% by mass, 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 from 800 to 1,000,000, more preferably from 800 to 200,000, and from 800 to 100,000. More preferably it is. 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 suitably imparted.
In the present specification, the number average molecular weight is a value in terms of standard polystyrene measured by 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 this 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. For example, in the amino group such as a primary amino group, a secondary amino group, and a tertiary amino group A nitrogen atom is mentioned.
The polyamine compound is not particularly limited as long as it can bond to 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 amino groups selected from the group consisting of a primary amino group, a secondary amino group and a tertiary amino group is preferred.

Specific examples of the polyamine compound include alkylene diamines, polyalkylene polyamines, silicon compounds having a plurality of basic nitrogen atoms, and the like. Examples of the alkylene diamines include alkylene diamines having 2 to 10 carbon atoms such as ethylene diamine, 1,2-propylene diamine, 1,3-propylene diamine, 1,4-butane diamine, and 1,6-hexamethylene diamine. Is 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, 3- [N- (2 And silane coupling agents having a plurality of basic nitrogen atoms, such as -aminoethyl) amino] propyltriethoxysilane.
In addition, the silane coupling agent corresponding to a polyamine compound shall not correspond to the said 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 suitably expressing gas barrier properties and the water dispersion stability of the aqueous polyurethane resin. / G is more preferable, 200 to 1700 mg KOH / g is particularly preferable, and 300 to 1500 mg KOH / g is most preferable. The amine value of the polyamine compound is measured by the following method.
[Method for measuring amine value]
Weigh 0.5-2 g of the sample accurately (sample amount Sg). 30 g of ethanol is added to a precisely weighed sample and dissolved. Bromophenol blue is added as an indicator to the resulting solution and titrated with a 0.2 mol / L ethanolic hydrochloric acid solution (titer f). The point at which the color of the solution has changed from green to yellow is taken as the end point, and the amine value is determined using the following calculation formula 1 using the titration amount (AmL).
Calculation formula 1: Amine number = A × f × 0.2 × 56.108 / S [mg KOH / g]

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

The aqueous polyurethane resin is usually used in a state of being dispersed in an aqueous medium (aqueous dispersion).
Examples of the aqueous medium include water, water-soluble or hydrophilic organic solvents, 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; and nitriles such as acetonitrile. Etc.
As said aqueous medium, what contains water or water as a main component is preferable. 70 mass% or more is preferable and, as for content of the water in the said aqueous medium, 80 mass% or more is more preferable.
The aqueous medium may or may not contain a neutralizing agent (base) that neutralizes the acid groups of the acid group-containing polyurethane resin. Usually a neutralizing agent is included.

In the aqueous dispersion of the aqueous polyurethane resin, the average particle diameter of the dispersed particles (polyurethane resin particles) is not particularly limited, but the uniform dispersion between the dispersed particles and other materials and the dispersion stability of the barrier coating composition. From the viewpoint of ensuring the gas barrier properties and preferably exhibiting gas barrier properties, it is preferably 20 nm to 500 nm, more preferably 25 nm to 300 nm, and even more preferably 30 nm to 200 nm.
In the present specification, the average particle size is measured with 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). This is a measured value.

A commercially available product may be used as the aqueous polyurethane resin, or a product produced by a known production method may be used.
The manufacturing method of the said aqueous polyurethane resin is not specifically limited, The normal water-ization technology of a polyurethane resin, such as an acetone method and a prepolymer method, is used. In the urethanization reaction, a urethanization catalyst such as an amine catalyst, a tin catalyst, or a lead catalyst 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 at least one of them. More specifically, a polyisocyanate compound, a polyhydroxy acid, and a polyol component are reacted in an inert organic solvent (especially a hydrophilic or water-soluble organic solvent), and a prepolymer having an isocyanate group at the terminal is reacted. A polymer is formed, neutralized with a neutralizing agent, dissolved or dispersed in an aqueous medium, added with a chain extender component, reacted to remove the organic solvent, thereby removing the 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 as necessary.
In the case of heating, the heating temperature is preferably 30 to 60 ° C.

The total content of the aqueous polyurethane resin and the high-polarity resin having an ethylene chain 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. It is more preferably 1 to 15 parts by mass.

The high polar resin having an ethylene chain means a resin having an ethylene chain and the following highly polar functional group.
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 suitably expressing gas barrier properties.

The highly polar resin having an ethylene chain is preferably a copolymer of ethylene and a compound having a vinyl group.
Examples of the copolymer of ethylene and a compound having a vinyl group include ethylene-vinyl alcohol copolymer, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene -Ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer and the like.
Of these, ethylene-vinyl alcohol copolymer and ethylene-acrylic acid copolymer are preferable, and ethylene-vinyl alcohol copolymer is more preferable from the viewpoint of suitably expressing gas barrier properties.

The high polarity resin having an ethylene chain preferably has an ethylene ratio of 0.5 to 30 mol%.
By setting it as the range of the said ethylene ratio, the solubility to water and alcohol can be made favorable.
The highly polar resin having an ethylene chain is more preferably 1.0 to 15 mol%.

The highly polar resin having an ethylene chain preferably has an ethylene chain in the main chain.
By having an ethylene chain in the main chain, water resistance can be improved.
In the present invention, “main chain” refers to the longest chain forming a polymer.

The highly polar resin having an ethylene chain preferably has a saponification degree of 90 to 100%, more preferably 95 to 100%, and still more preferably 97 to 100%.

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

As the highly polar resin having an ethylene chain, a commercially available resin may be used, or a resin satisfying the ethylene ratio, the saponification degree, the average polymerization degree and the like may be produced by a known production method.

The mass ratio (mass ratio of solid content) of the high polarity resin having an ethylene chain to 100 mass parts of the aqueous polyurethane resin is preferably 15 to 150 mass parts.
By setting it as the said range, water resistance and gas barrier property can be made to make compatible both suitably.

Examples of the silane coupling agent include a compound 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, a (meth) acryl 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) acryl group shows both an acryl group and a methacryl 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 above silane coupling agent having an 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) 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 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. Especially, it is preferable that it is a silane coupling agent which has an epoxy group.
The epoxy group-containing silane coupling agent has good reactivity with the functional group of the water-based polyurethane resin and the high-polarity resin having the ethylene chain, and further has excellent reactivity with the vapor deposition layer described later. The laminate strength and gas barrier properties can be preferably 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, any of aqueous and non-aqueous solvents can be used as long as it can dissolve the aqueous polyurethane resin, the high-polarity resin having an ethylene chain, 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 ones 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, tert-butyl alcohol and the like. Alcohols are mentioned, and those containing at least one of these can be suitably used.

The solvent is preferably 5 to 60 parts by mass, more preferably 20 to 50 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 is generally known as an anti-blocking agent, and includes inorganic fine particles such as silica, talc, alumina, calcium carbonate, titanium oxide, magnesium carbonate, clay and kaolin, colloidal silica, surface activity and the like. You may mix | blend.

Since the barrier coating composition of the present invention has the above-described configuration, it can be suitably used as a laminate for 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. For example, the solvent is added to the aqueous polyurethane resin, the high polarity resin having an ethylene chain, and the silane coupling agent. A coating solution having a predetermined concentration can be prepared by sufficiently stirring and mixing at room temperature.
In addition, when adding the said silane coupling agent, since there exists a possibility that it may aggregate if it adds at a stretch, it is preferable to add, stirring slowly.

[Composite film]
A composite film having at least a base film, a vapor deposition layer, and a coat layer in this order, wherein the coat layer is formed by applying the barrier coating composition. Is also one aspect of the present invention.

The base film is not particularly limited as long as it is formed of a thermoplastic resin 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, Polyolefin resins such as ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ionomer resin; Polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; Nylon-6, Nylon-6, 6, Metaxylenediamine-adipic acid condensation polymer, amide resins such as polymethylmethacrylamide, acrylic resins such as polymethylmethacrylate; polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-buta Styrene such as ene copolymer, polyacrylonitrile, acrylonitrile resin; Hydrophobized cellulose resin such as cellulose triacetate and cellulose diacetate; Halogen such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, Teflon (registered trademark) Containing resin; hydrogen bonding resin such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, cellulose derivative; polycarbonate resin, polysulfone resin, polyether sulfone resin, polyether ether ketone resin, polyphenylene oxide resin, polymethylene oxide resin, Examples include engineering plastic resins such as liquid crystal resins. These may be used alone or in combination of two or more.
The base film is preferably 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 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 vapor deposition layer is preferably formed on the substrate film by a vacuum process such as vacuum vapor deposition, sputtering, plasma vapor deposition (PVD method / CVD), etc., using 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.
Especially, since it is excellent in adhesiveness with the coating layer formed by apply | coating the barrier coating composition of this invention, it is preferable that it is 1 or more types of vapor deposition layers chosen from the group which consists of a silica and an alumina.

The thickness of the vapor deposition layer is not particularly limited, but is preferably 0.1 to 500 nm, and 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, a doctor knife method, an air knife / nozzle coating method, a bar coating method, a spray coating method, a dip coating method, and The coating method etc. which combined these methods 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.
When the coating layer is thinner than 0.01 μm, it may be difficult to obtain high gas barrier properties, and even if the thickness exceeds 5 μm, no significant improvement in gas barrier properties may be observed.

The composite film of the present invention may have a printed layer.
As the above-mentioned printing layer (printing layer for contents display and decoration function), organic solvent type printing ink composition, water-based printing ink composition and the like conventionally used in soft packaging, usually gravure printing method and It can be formed by printing with a flexographic printing method.

Examples of the organic solvent-type 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-based printing ink composition containing chlorinated polypropylene), JP-B-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 JP-A-07-324179 (pigments, polyurethane resins, non-aromatic / non-ketone organic solvent-based printing ink compositions), and the like.

Examples of the water-based printing ink composition include, for example, Japanese Patent Application Laid-Open No. 06-155694 (water-based printing ink composition containing a pigment, an acrylic binder resin, and a hydrazine-based crosslinking agent), and Japanese Patent Application Laid-Open No. 06-206972 (pigment, water). And water-based printing ink compositions disclosed in water-based printing ink compositions containing polyurethane binder resins).

Recently, as environmentally friendly inks, water-based printing ink compositions and organic solvent-based printing ink compositions have been used that do not use aromatic and ketone-based organic solvents as much as possible. 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, and a sealant layer.

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

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

[Production method of composite film]
It does not specifically limit as a method to manufacture the composite film of this invention, A conventional method can be selected suitably and can be used.
For example, the following methods (a) to (d) may be mentioned.
(A) After forming a vapor deposition layer on the base film (the base film may be a laminated film having a vapor deposition layer) by the above-described method, the barrier coating composition and the adhesive composition are sequentially applied. A method of obtaining a composite film by laminating a sealant layer after processing.
(B) After forming a vapor deposition layer by the method mentioned above to a base film (a base film may be a laminated | multilayer film which has a vapor deposition layer), the said adhesive composition, barrier coating composition, and adhesive agent A method of obtaining a composite film by sequentially applying the composition and then laminating a sealant layer.
(C) After forming a vapor deposition layer by the method mentioned above on the base film (The substrate film may be a laminated film having a vapor deposition layer), the ink composition was first printed to form a printing layer. Then, after apply | coating the said adhesive composition, barrier coating composition, and adhesive composition one by one, the composite film is obtained by laminating | stacking a sealant layer.
(D) After forming a vapor deposition layer by the method mentioned above in a base film (a base film may be a laminated | multilayer film which has a vapor deposition layer), the said adhesive composition, barrier coating composition, and adhesive agent For example, a method of obtaining a barrier composite film by sequentially coating the composition, printing the ink composition to form a printed layer, and further laminating a sealant layer.

In addition, about the coating method of the said adhesive composition, the roll coating method using a normal gravure cylinder etc., a doctor knife method, an air knife nozzle coating method, a bar coating method, a spray coating method, a dip coating method, and these The coating method etc. which combined these methods can be used.
Moreover, in order to form the said printing layer, a gravure printing system and a flexographic printing system can be used normally.

In the composite film of the present invention, the thickness of the adhesive layer (after drying) is preferably 2 to 3 μm.
If the thickness of the adhesive layer is less than 2 μm, the adhesion between the coat layer and the other layer may be reduced. On the other hand, if the thickness is greater than 3 μm, the increase in the adhesion commensurate with the increase in the thickness is not observed. In addition, when the composite film is used as a packaging bag, there is a possibility that good handleability cannot be obtained.
In addition, when the coating film which has the film thickness in the said range is not obtained by one time of application | coating, it is also possible to perform many times of application.

In the case of providing other functional layers, a barrier composite film suitable for the purpose can be produced by combining good means for providing each functional layer and the methods (a) to (d). .

Since the barrier coating composition of the present invention has the above-described configuration, a composite film excellent in laminate strength, seal strength, water vapor barrier property, and oxygen barrier property under boil conditions and watering conditions can be obtained.
Moreover, the composite film of this invention can be used conveniently as a barrier film or a packaging material.

The present invention will be described in more detail with reference to the following examples, 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)
<Water-based polyurethane resin>
Takelac WPB-341 (solid content 30%, glass transition temperature 115 ° C., manufactured by Mitsui Chemicals)
<High polarity resin having ethylene chain>
EXEVAL RS-2117 (average polymerization degree 1700, saponification degree 97.5-99.0%, ethylene ratio 3.0 mol%, main chain having ethylene chain, manufactured by Kuraray Co., Ltd.)
Soarnol SG525 (saponification degree 99.0-100%, ethylene ratio 26 mol%, main chain having ethylene chain, manufactured by Nippon Synthetic Chemical Co., Ltd.)
<High polarity resin without ethylene chain>
Gohsenol NH-18 (average polymerization degree 1800, saponification degree 98.0 to 99.0%, ethylene ratio 0 mol%, 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 RS-2117 aqueous solution>
10 parts by weight of EXEVAL RS-2117 was added to 90 parts by weight of purified water, followed by stirring at 95 ° C. for about 2 hours to obtain an RS-2117 aqueous solution (solid content 10%).

<Preparation of SG525 solution>
In a mixed solvent of 44.2 parts by mass of purified water and 71.996 parts by mass of n-propyl alcohol (NPA), 15 parts by mass of Soarnol SG525, 13 parts by mass of hydrogen peroxide having a concentration of 30%, and FeSO ₄ of 0. 004 parts by mass was added, and the mixture was heated to 80 ° C. with stirring and reacted for 2 hours.
Then, it cooled and the catalase was added so that it might become 3000 ppm, the residual hydrogen peroxide was removed, and substantially transparent SG525 aqueous solution (solid content 15%) was obtained.

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

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

<Production of alumina-deposited PET>
On one surface of a PET film (E5100, thickness 12 μm, manufactured by Toyobo Co., Ltd.), an isocyanate compound (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and a saturated polyester (“Byron 300 manufactured by Toyobo Co., Ltd.) in a mass ratio of 1: 1. The blended mixture was applied and dried to form an adhesive layer having a thickness of 0.1 μm. Next, aluminum is evaporated using a vacuum deposition device, oxygen gas is supplied using a gas flow rate control device, 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, and alumina-deposited PET was obtained.

Example 1
While stirring 22.2 parts by mass of Takelac WPB-341, 28.5 parts by mass of an RS-2117 aqueous solution with a solid content of 10%, 30.9 parts by mass of ion-exchanged water, and 18.1 parts by mass of isopropyl alcohol were added. Thereafter, 0.3 parts 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 vapor deposition layer surface of silica vapor deposition PET produced above, coating composition 1 is No.2. The coating was applied with a 6 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 Co., Ltd.) was applied to the obtained coating layer (coating amount 0.8 g / m ² after drying). Coating was performed with a 4-wire bar, and a sealant film (RXC-22, thickness 60 μm, manufactured by Mitsui Chemicals, Inc.) was laminated 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 base film was changed to the alumina-deposited PET produced above.

(Example 3, Comparative Examples 1 to 3)
Coating compositions 2 to 5 were prepared according to the formulation shown in Table 1, and composite films were obtained in the same manner as in Example 1.

(Comparative Examples 4 to 5)
A composite film was obtained in the same manner as in Examples 1 and 2, except that the coating composition was not used.

[Evaluation]
<Measurement of laminate strength (N / 15mm)>
(1) Normal conditions (dry conditions)
Each composite film of Examples 1 to 3 and Comparative Examples 1 to 5 was cut to a width of 15 mm.
The laminate strength was measured for the T-type peel strength using a peel tester (manufactured by Yasuda Seiki Co., Ltd.) at a peel rate of 300 mm / min. The results are shown in Table 2.
(Boil condition)
The laminate strength was measured in the same manner as in the dry condition except that each of the composite films of Examples 1 to 3 and Comparative Examples 1 to 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.
(2) Watering conditions (dry conditions)
Each composite film of Examples 1 to 3 and Comparative Examples 1 to 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 with water on the peel surface of each sample piece. The results are shown in Table 2.
(Boil condition)
The laminate strength was measured in the same manner as in the dry condition except that each of the composite films of Examples 1 to 3 and Comparative Examples 1 to 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.
In addition, what attached | subjected F to the number in Table 2 means that the composite film fractured | ruptured without peeling in the intensity | strength of the number.

<Seal strength (kg / 15mm)>
Each composite film of Examples 1 to 3 and Comparative Examples 1 to 5 is formed into a bag using an impulse sealer (manufactured by Fuji Impulse Sealer), and a peeling speed of 300 mm / min using a peeling tester (manufactured by Yasuda Seiki) The seal strength was measured under the following conditions. The results are shown in Table 2.
In addition, what attached | subjected F to the number in Table 2 means that the composite film fractured | ruptured without peeling in the intensity | strength of the number.

<Oxygen transmission rate (cc / m ² / day / atm)>
The composite films of Examples 1 to 3 and Comparative Examples 1 to 5 (for oxygen permeability test) were allowed to stand in an atmosphere of 25 ° C. and 90% RH for 72 hours, and then an oxygen permeability measuring device according to JIS K7126 B method The oxygen permeability (OTR value) was measured using a product (manufactured by Mocon, product name: OX-TRAN 1/50).
Note that 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 of Examples 1 to 3 and Comparative Examples 1 to 5 (for water vapor transmission rate test) were measured for water vapor transmission rate (WVTR value) as follows according to JIS Z0222.
Each of the composite films of Examples 1 to 3 and Comparative Examples 1 to 5 was made into a bag with the same volume using a size of 10 cm × 10 cm, packed with 15 g of calcium chloride, and 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 bag mass. The results are shown in Table 2.

In Examples 1 to 3 in which composite films were prepared using the barrier coating composition of the present invention, the laminate strength, seal strength, water vapor barrier property, and oxygen barrier property were excellent in boil conditions and watering conditions. .
On the other hand, in Comparative Example 1 in which a composite film was prepared using the coating composition 3 containing no ethylene chain and having a high polarity resin, the gas barrier property was inferior, and the coating composition containing a high polarity resin having no ethylene chain In Comparative Example 2 in which the composite film was prepared using the product 4, the laminate strength was poor in the watering condition, and also in Comparative Example 3 in which the composite film was prepared using the coating composition 5 containing no silane coupling agent. The laminate strength under watering conditions was inferior.
Moreover, in Comparative Examples 4 and 5 in which the composite film was produced without using the coating composition, the laminate strength, seal strength, water vapor barrier property, and oxygen barrier property in the boil condition and watering condition were inferior.

Claims

A barrier coating composition comprising an aqueous polyurethane resin, a highly polar resin having an ethylene chain, and a silane coupling agent.
The barrier coating composition according to claim 1, wherein the mass ratio of the high polarity resin having an ethylene chain 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 an ethylene chain has an ethylene chain ratio of 0.5 to 30 mol%.
4. The barrier coating composition according to claim 1, wherein the highly polar resin having an ethylene chain has an ethylene chain in the main chain.
The barrier coating composition according to any one of claims 1 to 4, 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 5, which is used for laminating.
A composite film having at least a base 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 6. A composite film characterized by being a thing.
The composite film according to claim 7, wherein the vapor deposition layer is one or more vapor deposition layers selected from the group consisting of silica and alumina.