JP6852948B2 - Ink composition and packaging material - Google Patents

Description

The present invention relates to ink compositions and packaging materials for packaging materials. More specifically, the present invention relates to an ink composition for a packaging material which is excellent in hiding property and gas barrier property and can form an ink layer having good adhesion to a base film, and a packaging material obtained by using the ink composition.

For packaging materials such as packaging films and packaging sheets, barrier properties such as aluminum vapor deposition and silica vapor deposition are used on the base material used for the purpose of preventing deterioration of the contents of foods and extending the consumption period. It has been considered to provide a layer for granting silica. Further, in printing for packaging materials, white ink has been used on the entire surface or a part of the base material as a base for printing a pattern or the like on the base material. Here, using polyurenne resin as the binder resin used for the ink for packaging film has good adhesiveness (adhesion) with polypropylene (PP), polyethylene terephthalate (PET), nylon (NY), etc. used as the base material. It is known, for example, in Patent Document 1, that it is preferable to obtain (sex). Further, in Patent Document 2, a polyurenne resin is used as a binder resin, and a gravure white ink composition containing a silica layer and an alumina layer on the surface of titanium oxide particles is printed on a base material of a packaging material to form a white ink layer. It is known to do.

Japanese Unexamined Patent Publication No. 5-97959 Japanese Unexamined Patent Publication No. 2016-104842

However, as is known in Patent Document 1 and Patent Document 2, when polyurenne resin is used as the binder resin used for the ink for packaging film, the adhesiveness (adhesion) of PP, PET, NY and the like is obtained. However, the gas barrier property was not sufficient.

An object of the present invention is an ink composition for obtaining a packaging material having excellent concealing property and gas barrier property when a white ink layer is formed on a base material of a packaging material such as a packaging film or a packaging sheet, and an ink composition thereof. The purpose is to provide the packaging material used.

As a result of diligent research to achieve the above object, the present inventors have found that the above problem can be solved by setting the binder resin and other components used in the ink composition to a specific composition. The present invention has been completed.
That is, the present invention relates to the following [1] to [10].

[1] An ink composition for a packaging material, which contains (A) a vinylidene chloride-based copolymer resin, (B) titanium dioxide, and (C) a plate-like filler.
[2] The content of the component (A) is 2 to 50% by mass, the content of the component (B) is 1 to 50% by mass, and the content of the component (C) is 1 to 50% by mass. The ink composition according to the above [1].
[3] The ink according to the above [1] or [2], wherein the mass ratio of the component (A) to the total amount of the component (B) and the component (C) is 96/4 to 10/90. Composition.
[4] The ink composition according to any one of the above [1] to [3], wherein the component (C) is at least one selected from clay minerals, ceramics, metals, metal oxides and metal salts. ..
[5] The ink composition according to any one of the above [1] to [4], wherein the component (C) is mica or barium sulfate as the plate-shaped filler.
[6] The ink composition according to any one of the above [1] to [5], which further contains an organic solvent.
[7] The ink composition according to the above [6], wherein the organic solvent is at least one selected from ketones, ethers, esters, amides, aromatic hydrocarbons and aliphatic hydrocarbons. ..
[8] The ink composition according to the above [6], wherein the organic solvent is tetrahydrofuran or methyl ethyl ketone.
[9] A packaging material having a first base material layer and a dry film layer of an ink, wherein the dry film layer of the ink is obtained from the ink composition according to any one of the above [1] to [8]. Packaging material to be used.
[10] The packaging material according to the above [9], which further has a second base material layer on the dry film layer of the ink.

By using the ink composition of the present invention as a packaging material, it is possible to provide a packaging material having excellent concealing property and gas barrier property.

The ink composition for packaging materials of the present invention contains (A) a vinylidene chloride-based copolymer resin, (B) titanium dioxide, and (C) a plate-like filler.
Hereinafter, the ink composition for a packaging material of the present invention will be described in detail. In addition, in this specification, the preferable provision can be arbitrarily adopted, and it can be said that the combination of preferable ones is more preferable.

[Components of Ink Compositions for Packaging Materials]
<(A) Vinylidene chloride-based copolymer resin>
The ink composition for packaging materials of the present invention contains a vinylidene chloride-based copolymer resin as the component (A). In the ink composition for packaging materials of the present invention, the vinylidene chloride-based copolymer resin of the component (A) has a role as a binder resin.
The vinylidene chloride-based copolymer resin of the component (A) is a resin obtained by copolymerizing vinylidene chloride with another monomer component.
As the vinylidene chloride-based copolymer resin, the content ratio of vinylidene chloride is 50% by mass or more and 99% by mass or less, and the content ratio of the monomer copolymerizable with vinylidene chloride is 1% by mass or more and 50% by mass or less. Is preferable from the viewpoint of improving the gas barrier property.
Examples of the monomer component copolymerizable with vinylidene chloride include vinyl chloride, acrylonitrile, acrylic acid, acrylic acid alkyl ester (alkyl group having 1 to 18 carbon atoms), methacrylic acid, and methacrylic acid alkyl ester (alkyl group carbon number of carbon number). 1-18), one or more selected from maleic anhydride, methacrylic acid, alkyl itaconic acid ester, vinyl acetate, ethylene, propylene, isobutylene, butadiene and the like can be mentioned, but the present invention is not particularly limited thereto. As the copolymerizable monomer, one type may be used alone, or two or more types may be used in combination.

The weight average molecular weight (Mw) of the vinylidene chloride-based copolymer resin is not particularly limited, but is preferably 20,000 to 200,000, and more preferably 50,000 to 150,000. The weight average molecular weight (Mw) of the vinylidene chloride-based copolymer resin used in the present invention is determined by the gel permeation chromatography method (GPC method) described below. The polyvinylidene chloride-based copolymer resin can be produced by a conventionally known method, but various commercially available products can also be used. As a commercially available product, Saran resin manufactured by Asahi Kasei Corporation or the like can be used.

Method for Measuring Weight Average Molecular Weight (Mw) of Vinylidene Chloride Copolymer Resin The weight average molecular weight (Mw) of the vinylidene chloride-based copolymer resin was measured by using GPC (gel permeation chromatography). The measurement was carried out by connecting three columns KF-LG, KF-2002 and KF-2004 manufactured by SHODEX in series, using THF (tetrahydrofuran) as a mobile phase, and measuring at 40 ° C. and a flow velocity of 0.3 mL / min. A differential refractive index detector (SE-62 manufactured by Showa Denko) was used to detect the eluted components. Genuine polystyrene was used as the standard sample, and a calibration curve was prepared using this to calculate the weight average molecular weight (Mw).

<(B) Titanium dioxide>
The ink composition for packaging materials of the present invention contains titanium dioxide as the component (B). Since the base material layer such as a film or sheet constituting the packaging material is generally transparent, it is necessary to sufficiently conceal it with an inconspicuous color such as a white background when printing a pattern or the like. .. In the ink composition for packaging materials of the present invention, the titanium dioxide component (B) is used to print the ink composition on a base material layer such as a film or sheet constituting the packaging material to form a dry film layer of the ink. At that time, it is used for the purpose of improving the concealment property.
As the titanium dioxide component (B), any of rutile type (tetragonal high temperature type), anatase type (tetragonal low temperature type), and brookite type (orthorhombic crystal) may be used. For example, titanium oxide particles "Typake" manufactured by Ishihara Sangyo Co., Ltd., titanium oxide "JR series" manufactured by TAYCA Corporation, and the like are available. The average particle size of the titanium oxide particles (in the case of forming aggregates, the particle size of the aggregates, so-called secondary particle size) is, for example, 0.01 to 1 μm, preferably 0.1 to 0. It is 5 μm, more preferably 0.2 to 0.5 μm. When the average particle size is 0.01 μm or more, the white density is lowered and the hiding property is good. Further, if the thickness is 1 μm or less, there is less risk of so-called “plate fog” (printing failure due to poor ink scraping of a portion other than the image line portion of the plate) during gravure printing, which is preferable. The titanium oxide content is preferably 10 to 60% by mass, more preferably 20 to 55% by mass, based on the total mass of the non-volatile content (solid content) of the resin composition from the viewpoint of concealment and barrier properties. Is.

The particle surface of titanium dioxide used in the present invention may be coated with a hydrous oxide and / or an oxide containing elements such as aluminum, magnesium, silicon, zirconium, zinc and tin. Further, the surface treatment may be performed with a polyol containing no nitrogen atom, an organic silicon compound, alkanolamines, higher fatty acids and the like. In particular, by using silica-treated titanium dioxide, the concealing property can be improved.

<(C) Plate-shaped filler>
The ink composition for packaging materials of the present invention contains a plate-like filler as the component (C). In the packaging material ink composition of the present invention, the plate-like filler of the component (C) is used for the purpose of further improving the gas barrier property of the packaging material.
Examples of the plate-like filler of the component (C) include clay minerals, ceramics, metals, metal oxides (excluding titanium oxides), metal salts and the like.
Examples of clay minerals include mica, talc, montmorillonite, clay, and graphite. Examples of ceramics include glass flakes, silicon nitride, silicon carbide and the like. Examples of the metal include metal foils such as aluminum, tin, lead, iron, gold, silver, copper, and zinc, and plate-shaped metals. Examples of the metal oxide include plate-shaped alumina and plate-shaped barium sulfate as a metal salt. Only one type of the plate-shaped filler may be used, or a plurality of types may be used in combination.
It is particularly preferable to use mica or plate-shaped barium sulfate as the plate-shaped filler.
The average particle size of the plate-shaped filler is 1 to 200 μm, preferably 3 to 100 μm, and the thickness is 0.1 to 10 μm, preferably 0.5 to 5 μm.

<Content rate of each component of (A), (B) and (C)>
The contents of the vinylidene chloride-based copolymer resin of the component (A), titanium dioxide of the component (B), and the plate-like filler of the component (C) contained in the ink composition for packaging materials of the present invention are (A). It is preferable that the component is 2 to 50% by mass, the component (B) is 1 to 50% by mass, and the component (C) is 1 to 50% by mass in order to obtain a packaging material having excellent concealing property and gas barrier property. More preferably, the component (A) is 2 to 40% by mass, the component (B) is 5 to 45% by mass, and the component (C) is 5 to 45% by mass.

Further, the mass ratio of the component (A) to the total amount of the component (B) and the component (C) can be used in the range of 96/4 to 10/90. In particular, 60/40 to 10/90 is preferable, and 40/60 to 15/85 is more preferable, in order to obtain a packaging material having excellent concealing property and gas barrier property.

<Organic solvent>
The ink composition for packaging materials of the present invention is used as a solution. It is desirable to use an organic solvent in order to dissolve the component (A) and to make the components (B) and (C) into a uniform solution. The organic solvent is not particularly limited as long as the component (A) can be dissolved, but ketones, ethers, esters, amides, aromatic hydrocarbons, aliphatic hydrocarbons, and the like. A chlorinated organic solvent or the like can be used. Examples of the ketones include compounds such as methyl ethyl ketone, methyl isobutyl ketone, and diisopropyl ketone. Examples of ethers include compounds such as tetrahydrofuran, dioxane, diethyl ether, methyl ethyl ether, and dimethyl ether. Examples of the esters include compounds such as ethyl acetate, butyl acetate, propyl acetate and isopropyl acetate. Examples of amides include dimethylformamide. Examples of aromatic hydrocarbons include compounds such as benzene, toluene, and xylene. Examples of aliphatic carbonized waters include compounds such as hexane, cyclohexane, and cyclohexanone. Further, as the chlorinated organic solvent, compounds such as methyl chloride, methylene chloride, chloroform, carbon tetrachloride, ethyl chloride, ethylene dichloride, chloroacetone, chlorotoluene, chlorobenzene and dichlorobenzene can be exemplified. Among these organic solvents, polar organic solvents are preferable, and tetrahydrofuran or methyl ethyl ketone is particularly preferable. It is also preferable to use a non-polar organic solvent compatible with these in combination.
The content of the organic solvent can be preferably 20 to 80% by mass, more preferably 30 to 70% by mass in the ink composition for packaging materials of the present invention in consideration of printability.

<Colorant>
In the ink composition for packaging materials of the present invention, other colorants such as pigments and dyes may be used in combination with titanium dioxide as the component (B), if necessary. Pigments used as colorants include colored inorganic pigments such as dark blue, ultramarine blue, red iron oxide, iron black, and yellow iron oxide, monoazo pigments, disazo pigments, condensed azo pigments, phthalocyanine pigments, and anthracinone pigments. , Kinacridone pigments, isoindolinone pigments, thioindigo pigments, colored organic pigments such as pyrolopyrrole pigments, white pigments such as zinc oxide and barium sulfate, silver pigments such as aluminum paste, and carbon black, azomethine azo pigments, And black pigments such as perylene pigments can be used.

<Other additives>
The ink composition for packaging materials of the present invention may further contain other additives, if necessary. Examples of other additives include anti-blocking agents, pigment dispersants, leveling agents, plasticizers, matting agents, anti-sedimenting agents, defoaming agents, silane coupling agents and the like.

The blocking inhibitor is added for the purpose of preventing blocking of printed matter, and as the blocking inhibitor, an inorganic filler-based blocking inhibitor such as silica, barium sulfate, calcium carbonate, and talc, polyethylene wax, fatty acid amide, and fatty acid. An organic blocking inhibitor such as an ester can be exemplified. When silica is used as the blocking inhibitor, it is preferable to use dry method silica or wet method silica.

[Manufacturing method of ink composition for packaging material]
The method for producing the ink composition for packaging material of the present invention is not particularly limited, but can be produced, for example, as follows. The above-mentioned vinylidene chloride-based copolymer resin of the component (A), titanium dioxide of the component (B), and a plate-like filler of the component (C), which are essential components of the ink composition, are contained, and if necessary, An ink composition can be produced by preparing a mixture containing other resin components, other pigments, additives, an organic solvent, and the like.
The method for producing an ink composition of the present embodiment preferably includes a step (preparation step) of preparing a mixture containing the above-mentioned components (A), (B) and (C).

When the ink composition contains a colorant (pigment), the method for producing the ink composition is a step of finely dispersing the particles of the colorant (pigment) to a desired particle size in the preparation step or after the preparation step (dispersion step). ) Is preferably included. In this dispersion step, various dispersers such as a paint shaker, a ball mill, an attritor, a sand mill, a bead mill, a dyno mill, a roll mill, an ultrasonic mill, and a high pressure collision disperser can be used. In the dispersion step, one kind of disperser may be used for the dispersion treatment once or a plurality of times, or two or more kinds of dispersers may be used in combination for the dispersion treatment a plurality of times.

The method for producing the ink composition preferably includes a step (dilution step) of diluting the mixture after the preparation step or the dispersion liquid after the dispersion step to a desired viscosity with a diluting organic solvent. By this dilution step, the ink composition can be diluted with an organic solvent until the viscosity of the ink composition becomes the viscosity corresponding to the coating method, and the desired ink composition can be obtained.

[Packaging material]
The packaging material of the present invention has a dry film of ink by printing the ink composition of the present invention on a base material layer. Hereinafter, the packaging material of the present invention will be described.
<Base material constituting the base material layer>
Although various base materials can be used as the material of the base material layer, it is preferable to use plastic as the base material. The form is not particularly limited, and examples thereof include a film shape, a sheet shape, and a molded product. Among these forms, a film form or a sheet form is preferable, and a film form is more preferable, from the viewpoint of being used as a packaging material.

The material of the plastic base material to which the ink composition of the present invention can be preferably applied is not particularly limited, and for example, polyester such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyethylene (PE), polypropylene (PP) and the like. Polybutylene, and plastics such as polystyrene (PS), polycarbonate (PC), polymethyl methacrylate (PMMA), polyamide (PA), polyimide (PI), and celluloses can be mentioned. A film or sheet obtained from these plastics can be used as a material for the base material layer, but the film or sheet may be a non-stretched film or sheet, or a film such as uniaxially stretched or biaxially stretched. And sheets can also be used. By using a stretched film or sheet such as uniaxially stretched or biaxially stretched as the base material layer, a packaging material having excellent strength can be obtained. Therefore, the stretched film or sheet can be used as the base material layer. preferable.

The plastic base material may or may not be easily adhered. Among the above-mentioned plastic substrates, the PET film is more preferable because the ink composition is more likely to adhere better even if the easy-adhesion treatment is not performed. Since the ink composition exhibits good adhesion to both the easy-adhesion-treated PET film and the non-easy-adhesion-treated PET film, the presence or absence of the easy-adhesion treatment may be appropriately selected. When a non-easy-adhesion-treated PET film is used, the cost required for the easy-adhesion treatment can be reduced, which is more preferable.

When a film-like base material is used as the plastic base material, its thickness is not particularly limited, but is usually 1 to 200 μm, preferably 1 to 50 μm, more preferably 2 to 30 μm, and further preferably 2 to 25 μm. Is. Further, since the dry film layer of the ink formed from the ink composition of the present invention adheres well to the non-easy-adhesion-treated plastic base material, it is difficult to perform an easy-adhesion treatment such as corona treatment. A plastic film having a thickness of 10 μm or less is also suitable, and a plastic film having a thickness of less than 8 μm is also suitable.

When a sheet-shaped base material is used as the plastic base material, the thickness thereof is not particularly limited, but usually a material having a thickness of 200 μm or more is used. In addition, in this invention, the word "film sheet" means that both a film and a sheet are included.

When a film sheet is used as the plastic base material, various plastics described above can be used, but it is more preferable to use polyethylene terephthalate (PET) which can also be used in non-easy adhesion treatment.

<Dry ink layer>
The packaging material of the present invention has a dry film layer of ink in the base material layer, but may be provided on one side (one side) of the dry film layer of ink, or may be provided on both sides. Good. When a film sheet is used as the base material layer, the dry film layer of the ink is provided on one side (back surface) of the base material layer from the viewpoint that the film sheet can be suitably used as the base material layer of the packaging material. It is preferable to have.

In forming the dry film layer of ink on the base material layer, the ink composition of the present invention is printed, applied, or the like on the base material layer. The printing, coating, and the like of the ink composition are not particularly limited, and various coating methods such as various known printing methods and coating methods can be used depending on the purpose. Examples of the printing method include a gravure printing method, a flexographic printing method, an offset printing method, a letterpress printing method, a screen printing method, and the like. Examples of the coating method include a gravure coater, a comma coater, a roll coater, an air gun coating, and a dip coating.

Among the above-mentioned coating methods, the printing method is preferable, and the gravure printing method is more preferable from the viewpoint of mass production of a PET film suitable as a plastic base material at low cost. Therefore, as the film sheet, a printing film sheet (printing film or printing sheet) having an ink layer formed by printing the above-mentioned ink composition on the above-mentioned film-shaped or sheet-shaped plastic base material is preferable.

After printing, coating, etc., the ink composition of the present invention on the base material layer, a drying treatment is performed to remove volatile components such as organic solvents contained in the base material, thereby making the base material. The layer can have a dry film layer of ink. The conditions of the drying treatment are not particularly limited, but it is preferable to perform the heat treatment at a temperature at which volatile components such as an organic solvent can be removed. The heating temperature can be appropriately selected depending on the type of volatile matter such as an organic solvent. By performing the drying treatment in this way, a dry film layer of ink can be formed on the base material layer. The thickness of the dry film layer of the ink is usually about 1 to 20 μm, preferably 2 to 15 μm. When the thickness of the dry film layer of the ink is within this range, the hiding property can be sufficiently sufficient. By performing color printing on the dry film layer of the ink as needed, a pattern layer can be provided to enhance the design.

The packaging material of the present invention has a base material layer and a dry film layer of ink, and further, a base material layer is further provided on the dry film layer of the ink or the pattern layer on the dry film layer of the ink. Including what you have. That is, a dry film layer of ink is formed on the first base material layer, and then a second base material layer is formed on the dry film layer of the ink or on the pattern layer on the dry film layer of the ink. It is made up of. The first base material layer and the second base material layer may be the same base material layer or may be different base material layers. An adhesive can also be used when providing the second substrate layer. Examples of the adhesive include an ester-based polyurethane dry adhesive used as a dry laminate for flexible packaging (for example, manufactured by Dainichi Seika Kogyo Co., Ltd .: Seikabond E series) and an ether-based polyurethane dry adhesive (for example, Dainichisei). Kagaku Kogyo Co., Ltd .: Seika Bond A series), or polyester polyurethane anchor coating agent used for molten polyethylene extrusion lamination (for example, Dainichi Seika Kogyo Co., Ltd .: Seika Dyne 2710A / B), or partial seal Examples thereof include an ethylene vinegar-based part coat agent used for the purpose (for example, manufactured by Dainichi Seika Kogyo Co., Ltd .: Seikadyne 1001 B-93). The film thickness of the adhesive is about 1 to 3 μm (dry).

The packaging material according to one embodiment of the present invention includes the above-mentioned film sheet as a base material layer. This packaging material can be formed from the film sheet described above. The form of the packaging material is not particularly limited, and various forms such as a bag shape, a box shape, a pouch shape, and a pack shape can be adopted. Further, in the production of the packaging material using the film sheet, various sealing methods such as adhesion with an adhesive and heat sealing can be used in order to form the packaging material. The use of the packaging material is not particularly limited, and it can be used as a packaging material for, for example, foods, pharmaceuticals, medical materials, chemicals, and electrical / electronic parts.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, "part" and "%" in a test example, an example, and a comparative test example are based on mass unless otherwise specified.

Production Example 1) [Production of vinylidene chloride resin solution A (ink number: PVDC-1)]
Add 80 parts of tetrahydrofuran to 20 parts of the trade name "Saran (registered trademark) resin R204, Mw: 51,000", which is a vinylidene chloride resin manufactured by Asahi Kasei Chemicals Co., Ltd., and add 2 at 40 ° C. in a heating and dissolving kettle. The mixture was stirred for a time to obtain a vinylidene chloride resin solution A having a solid content of 20%.

Production Example 2 [Production of vinylidene chloride resin solution B (ink number: PVDC-2)]
To 20 parts of the trade name "Saran (registered trademark) resin F310, Mw: 115,000", which is a vinylidene chloride resin manufactured by Asahi Kasei Chemicals Co., Ltd., 80 parts of methyl ethyl ketone is added, and 2 at 40 ° C. in a heating dissolution kettle. The mixture was stirred for a time to obtain a vinylidene chloride resin solution B having a solid content of 20%.

Examples 1-8, Comparative Examples 1-4
With the compounding composition shown in Table 1, the vinylidene chloride resin solution obtained in Production Example 1 or Production Example 2, an organic solvent, barium sulphate plate (manufactured by Sakai Chemical Co., Ltd., trade name "barium sulphate A"), and dioxide. Titanium (manufactured by Teika Co., Ltd., trade name "Titanics JR-809") was dispersed with a bead mill to obtain white inks A-1 to A-8 and white inks B-1 to B-4.

Comparative Examples 5-7
Polyurethane resin solution (Samplen IB-465 solid content 30% manufactured by Sanyo Kasei Kogyo Co., Ltd.), methyl ethyl ketone, barium plate sulfate (manufactured by Sakai Chemical Co., Ltd., trade name "barium plate sulfate A"), with the composition shown in Table 2. Titanium dioxide (manufactured by Teika Co., Ltd., trade name "Titanics JR-809") was blended as shown in Table 2 and dispersed with a bead mill to obtain white inks C-1 to C-3.

Using the white inks obtained in Examples 1 to 8 and Comparative Examples 1 to 7, the following three types of plastic films (i) to (iii) were used as the base material, and the corona-treated surface of the plastic film was used. The white ink was printed by a gravure printing method so that the coating amount of each white ink was 4 μm (dry), and then dried in an oven at 60 ° C. for 20 seconds to form a dry film layer of the ink on the substrate. Then, a dry adhesive (E372 / C76 manufactured by Dainichi Seika Kogyo Co., Ltd.) was applied on the dry film layer by a gravure printing method so that the coating amount was 3 μm (dry), and a low density polyethylene film (TUX-) was printed. It was laminated with HC (thickness 60 μm) and bonded with a silicon roll heated to 80 ° C. to obtain a laminated product. The laminate was aged at 40 ° C. for 48 hours to react and cure the dry adhesive to obtain a packaging material.
(I) Biaxially stretched polypropylene film (OPP) [manufactured by Futamura Chemical Co., Ltd., "FOR" single-sided corona-treated product, thickness 25 μm]
(Ii) Biaxially stretched polyethylene terephthalate film (PET) [manufactured by Toyobo Co., Ltd., "E5102", single-sided corona-treated product, thickness 25 μm]
(Iii) Biaxially stretched nylon film (ONY) [manufactured by Toyobo Co., Ltd., "Harden N1102", single-sided corona-treated product, thickness 15 μm]
With respect to the PET coated material in which the dry film layer of the ink was formed by using PET as the base material described above, (1) optical density (OD value), (2) water vapor transmittance, and (3) were carried out by the following test methods. ) Oxygen permeability was measured. The results are shown in Tables 1 to 3.
Further, with respect to the packaging material obtained above, the lamination strength when three kinds of base materials (OPP, PET, ONY) were used was measured. The results are shown in Tables 1 to 3.

Reference examples 1-3
Reference Example 1 uses the vinylidene chloride resin solution A obtained in Production Example 1, and Reference Example 2 uses the vinylidene chloride resin solution B obtained in Production Example 2 as a base material, respectively, as a biaxially stretched polyethylene terephthalate film (PET). ) [Toyo Boseki Co., Ltd., "E5102", single-sided corona-treated product, thickness 25 μm] is printed on the corona-treated surface by the gravure printing method so that the coating amount is 4 μm (dry), and then placed in an oven at 60 ° C. The mixture was dried for 20 seconds to form a dry film layer of ink on a PET substrate to obtain a PET-coated product. The water vapor permeability and oxygen permeability of the obtained PET coated material were measured. The results are shown in Table 2. Reference Example 3 shows the water vapor permeability and oxygen permeability of the biaxially stretched polyethylene terephthalate film (PET) [manufactured by Toyobo Co., Ltd., "E5102", single-sided corona-treated product, thickness 25 μm] used as the base material. Shown in 2.

(1) Optical density (OD value)
The optical density (OD value) of the light-shielding films 1 to 10 was measured using a desktop transmission densitometer 361T manufactured by X-Rite. The measurement was performed 3 times and the average value was taken. The larger this value is, the higher the concealment property is.
(2) Water vapor permeability (cup method)
Based on JIS7129: 2008, the water vapor permeability of the PET coating material on which the dry film layer of the ink was formed was determined. In addition, the condition was measured by encapsulating calcium chloride at 40 ° C. × 90% RH × 48 hours.
The smaller this value is, the less water vapor permeates and the better the barrier property.
(3) Oxygen permeability Oxygen permeability at a temperature of 23 ° C and a humidity of 65% RH of a PET coating material on which a dry film layer of ink is formed using an oxygen permeability measuring device (OX-TRAN 2/21 ML manufactured by MOCON). Was measured. The smaller this value is, the more difficult it is for oxygen to permeate, and the better the barrier property is.
(4) Laminate strength The packaging material (laminate) was cut into a width of 15 mm, and the strength (unit: g / 15 mm width) when T-shaped peeling was performed at a tensile speed of 300 mm / min was measured with a tensile tester. .. The measurement was performed 3 times and the average value was taken. The higher this value, the higher the lamination strength.

As shown in Tables 1 to 3 above, the ink compositions of the present invention of Examples 1 to 8 have high optical density (OD value) and excellent hiding power, and were obtained by using these ink compositions. The water vapor permeability and oxygen permeability of the PET coated material show low values, indicating that the PET coating material has excellent gas barrier properties. On the other hand, in Comparative Examples 1 and 3 in which the plate-shaped filler is not used, it is shown that the gas barrier property is inferior. Further, in Comparative Examples 2 and 4 in which titanium dioxide is not used, it is shown that the optical density (OD value) is low and the hiding property is low. Further, in Comparative Examples 5 to 7 in which the polyvinylidene chloride-based copolymer resin was not used in the ink composition and the polyurethane resin was used, the lamination strength was shown to be excellent, but the gas barrier property was inferior and the gas barrier was inferior. It has been shown to be unsuitable for packaging materials that require sex.

In the ink composition of the present invention, when a white ink layer is formed on a base material of a packaging material such as a packaging film or a packaging sheet, a packaging material having excellent concealing property and gas barrier property can be obtained. , It can be suitably used as a packaging material having excellent design properties used for household goods, pet foods and the like.

Claims (8)

An ink composition for packaging materials, which contains (A) a vinylidene chloride-based copolymer resin, (B) titanium dioxide, and (C) a plate- shaped filler composed of plate-shaped barium sulfate. 1. The content of the component (A) is 2 to 50% by mass, the content of the component (B) is 1 to 50% by mass, and the content of the component (C) is 1 to 50% by mass. The ink composition according to. The ink composition according to claim 1 or 2, wherein the mass ratio of the component (A) to the total amount of the component (B) and the component (C) is 96/4 to 10/90. The ink composition according to any one of claims 1 to 3 , further comprising an organic solvent. The ink composition according to claim 4 , wherein the organic solvent is at least one selected from ketones, ethers, esters, amides, aromatic hydrocarbons and aliphatic hydrocarbons. The ink composition according to claim 4 , wherein the organic solvent is tetrahydrofuran or methyl ethyl ketone. A packaging material having a first base material layer and a dry film layer of ink, wherein the dry film layer of the ink is obtained from the ink composition according to any one of claims 1 to 6. The packaging material according to claim 7 , further comprising a second base material layer on the dry film layer of the ink.