JP7061723B1 - Ink composition for front printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition for front printing capable of forming a print layer having excellent gloss. SOLUTION: A printing ink composition containing a polyamide resin (A), nitrocellulose (B), a cellosolve-based solvent (D), and an organic solvent (E) other than the cellosolve-based solvent (D). The content of the polyamide resin (A) is 3 to 40% by mass with respect to the total mass of the ink composition for printing, and the content of the nitrocellulose (B) is the printing. It is 0.5 to 28% by mass with respect to the total mass of the ink composition for printing, and the content of the cellosolvent-based solvent (D) is 0.1 to 20 with respect to the total mass of the ink composition for front printing. The type and viscosity symbol, which is% by mass and is defined by the viscosity measurement of the nitrocellulose (B) in accordance with JIS K 6703: 1995, is H1 / 8, H1 / 4, H1 / 2, H1 or H2. Ink composition for surface printing. [Selection diagram] None

Description

The present invention relates to an ink composition for front printing.

Packaging materials (packages) used for packaging products such as foods and daily necessities are often printed on the base material used for the purpose of decoration and the like. For example, for food packaging, printed matter with a simple structure called a front printing method is used, in which printing is applied to the front side of the base material and printing is not applied to the back side of the base material that comes into contact with food. It is common to print.
As an ink composition for front printing, for example, Patent Document 1 discloses an ink composition containing a polyamide resin and nitrocellulose as a binder resin.

Japanese Unexamined Patent Publication No. 2016-29122

Since the front printing ink composition is printed on the front side of the base material, the printing layer formed from the front printing ink composition is arranged on the outer surface of the packaging material. When the gloss of the printed layer is lowered, the appearance of the packaging material is impaired, so that the printed layer is required to have a glossy feeling.
In the ink composition described in Patent Document 1, the glossiness of the formed print layer is not always sufficient.

An object of the present invention is to provide an ink composition for surface printing capable of forming a printing layer having excellent gloss.

The present invention has the following aspects.
[1] A printing ink composition containing a polyamide resin (A), nitrocellulose (B), a cellosolve-based solvent (D), and an organic solvent (E) other than the cellosolve-based solvent (D). There,
The content of the polyamide resin (A) is 3 to 40% by mass with respect to the total mass of the front printing ink composition.
The content of the nitrocellulose (B) is 0.5 to 28% by mass with respect to the total mass of the front printing ink composition.
The content of the cellosolve-based solvent (D) is 0.1 to 20% by mass with respect to the total mass of the front printing ink composition.
The type and viscosity symbol defined by the viscosity measurement of nitrocellulose (B) according to JIS K 6703: 1995 are H1 / 8, H1 / 4, H1 / 2, H1 or H2, and the ink composition for printing. thing.
[2] Further containing the chlorinated polyolefin resin (C),
The ink composition for printing according to the above [1], wherein the content of the chlorinated polyolefin resin (C) is 0.6 to 9% by mass with respect to the total mass of the ink composition for printing.
[3] The front printing ink according to the above [2], wherein the content of the chlorinated polyolefin resin (C) is 0.6 to 2.9% by mass with respect to the total mass of the front printing ink composition. Composition.
[4] The ink composition for printing on any of the above [1] to [3], wherein the cellosolve-based solvent (D) is at least one selected from the group consisting of butyl cellosolve, isopropyl cellosolve, and ethyl cellosolve.
[5] Any of the above [1] to [4], wherein the content of the cellosolve-based solvent (D) is 0.1 to 7% by mass with respect to the total mass of the front printing ink composition. Ink composition for surface printing.
[6] For printing according to any one of [1] to [5], wherein the content of the polyamide resin (A) is 6 to 40% by mass with respect to the total mass of the ink composition for printing. Ink composition.
[7] The printing ink composition according to [6], wherein the content of the polyamide resin (A) is 6 to 19% by mass with respect to the total mass of the printing ink composition.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an ink composition for front printing capable of forming a printing layer having excellent gloss.

Hereinafter, the present invention will be described in detail. The following embodiments are merely exemplary to illustrate the invention and are not intended to limit the invention to this embodiment alone. The present invention can be carried out in various embodiments as long as it does not deviate from the gist thereof.

[Ink composition for front printing]
The ink composition for printing (hereinafter, also simply referred to as “ink composition”) according to the embodiment of the present invention includes the polyamide resin (A), nitrocellulose (B), and cellosolve solvent (cellosolve solvent) shown below. D) and an organic solvent (E) other than the cellosolve-based solvent (D) are contained.
The ink composition preferably further contains the chlorinated polyolefin resin (C).
The ink composition contains a polyamide resin (A), a nitrocellulose (B), a chlorinated polyolefin resin (C), a cellosolve solvent (D), and an organic material, as long as the effects of the present invention are not impaired. A component (arbitrary component) other than the solvent (E) may be further contained.

<Polyamide resin (A)>
Examples of the polyamide resin (A) include thermoplastic polyamides which are polycondensations of polybasic acids and polyvalent amines and are soluble in organic solvents.
Examples of the polybasic acid include adipic acid, sebacic acid, azelaic acid, phthalic anhydride, isophthalic acid, suberic acid, glutaric acid, fumaric acid, pimelic acid, oxalic acid, malonic acid, succinic acid, maleic acid, and terephthalic acid. Examples thereof include 1,4-cyclohexyldicarboxylic acid, trimellitic acid, dimer acid and hydrogenated dimer acid. In addition to these polybasic acids, monocarboxylic acids such as acetic acid, propionic acid, lauric acid, palmitic acid, benzoic acid, and cyclohexanecarboxylic acid can also be used in combination.
Examples of the polyamine include polyamines and the like. Examples of the polyamine include aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine and methylaminopropylamine; aliphatic polyamines such as diethylenetriamine and triethylenetetramine; alicyclic polyamines such as cyclohexylene diamine and isophoronediamine; Examples thereof include aromatic polyamines such as amines, phenylenediamines and diaminodiphenylmethanes. In addition to these polyvalent amines, primary or secondary monoamines such as n-butylamine, octylamine, dielamine, monoethanolamine, monopropanolamine, diethanolamine, and dipropanolamine can also be used in combination.

As a specific example of the polyamide resin (A), a fatty acid made from a vegetable material or a thermoplastic polyamide resin using a polymerized fatty acid made from the fatty acid is generally used. Typical examples of fatty acids made from plants include tall oil, soybean oil, palm oil, palm oil, cashew nut oil, rice bran, and cacao beans. On the other hand, examples of the polymerized fatty acid include dimer acid and hydrogenated dimer acid obtained by hydrogenating the dimer acid.
One of these polyamide resins (A) may be used alone, or two or more thereof may be used in combination.

The content of the polyamide resin (A) is 3 to 40% by mass, preferably 4 to 40% by mass, more preferably 5 to 40% by mass, and 6 to 40% by mass with respect to the total mass of the ink composition. More preferably, 6 to 30% by mass is even more preferable, 6 to 20% by mass is particularly preferable, and 6 to 19% by mass is most preferable. When the content of the polyamide resin (A) is at least the above lower limit value, the gloss of the printed layer formed from the ink composition is enhanced. In addition, the adhesion, heat resistance, abrasion resistance, and blocking resistance of the printed layer to various substrates are improved. When the content of the polyamide resin (A) is not more than the above upper limit value, the heat resistance and abrasion resistance of the printed layer can be maintained satisfactorily.

<Nitrocellulose (B)>
The type and viscosity symbol specified by the viscosity measurement of nitrocellulose (B) according to JIS K 6703: 1995 are H1 / 8, H1 / 4, H1 / 2, H1 or H2, and H1 / 4, H1 /. 2, H1 or H2 is preferable, and H1 / 2, H1 or H2 is more preferable. If the type and viscosity symbol are nitrocellulose (vitrified cotton) having a viscosity higher than H1 / 8, the strength of the printed layer formed from the ink composition is increased. In particular, if the type and viscosity symbol are nitrocellulose cotton having a viscosity higher than H1 / 2, the abrasion resistance and heat resistance of the printed layer are improved. If the type and viscosity symbol are nitrocellulose cotton having a viscosity lower than that of H2, the gloss of the printed layer is enhanced.

The type and viscosity symbol are defined according to the time (falling time) at which a predetermined steel ball falls between marked lines in a nitrocellulose solution at a predetermined solid content concentration.
In the case of nitrocellulose having the type and viscosity symbol of H1 / 8, the falling time of the steel ball in the nitrocellulose solution having a solid content concentration of 25% by mass is 1.6 to 2.9 seconds.
In the case of nitrocellulose having the type and viscosity symbol of H1 / 4, the falling time of the steel ball in the nitrocellulose solution having a solid content concentration of 25% by mass is 3.0 to 8.9 seconds.
In the case of nitrocellulose having the type and viscosity symbol of H1 / 2, the falling time of the steel ball in the nitrocellulose solution having a solid content concentration of 20% by mass is 3.0 to 4.9 seconds. Alternatively, the falling time of the steel ball in the nitrocellulose solution having a solid content concentration of 25% by mass is 9.0 to 22.0 seconds.
In the case of nitrocellulose having the type and viscosity symbol of H1, the falling time of the steel ball in the nitrocellulose solution having a solid content concentration of 20% by mass is 5.1 to 9.0 seconds.
In the case of nitrocellulose having the type and viscosity symbol of H2, the falling time of the steel ball in the nitrocellulose solution having a solid content concentration of 12.2% by mass is 1.5 to 2.5 seconds. Alternatively, the falling time of the steel ball in the nitrocellulose solution having a solid content concentration of 20% by mass is 15.0 to 40.0 seconds.
One of these nitrocelluloses (B) may be used alone, or two or more thereof may be used in combination.

The content of nitrocellulose (B) is 0.5 to 28% by mass, preferably 0.7 to 25% by mass, more preferably 1 to 20% by mass, and 2 to 2 to 20% by mass with respect to the total mass of the ink composition. 15% by mass is particularly preferable. When the content of nitrocellulose (B) is at least the above lower limit value, the heat resistance and abrasion resistance of the printed layer formed from the ink composition are improved. When the content of nitrocellulose (B) is not more than the above upper limit value, the gloss of the printed layer is enhanced. In addition, the transparency of the print layer is improved.

<Chlorinated polyolefin resin (C)>
The chlorinated polyolefin resin (C) is a resin obtained by chlorinating a polyolefin by a known method.
Examples of the polyolefin include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, and polyolefins such as polybutene; modifications in which a carboxyl group, a hydroxy group, an acid anhydride group, etc. are introduced into these polyolefins. Examples include polyolefins.
As the chlorinated polyolefin resin (C), chlorinated polyethylene and chlorinated polypropylene are preferable, and chlorinated polypropylene is more preferable, from the viewpoint of excellent compatibility with the polyamide resin (A) and nitrocellulose (B) which are binder resins. ..
The amount of chlorine in the chlorinated polyolefin resin (C) is preferably 15 to 45% by mass with respect to the total mass of the chlorinated polyolefin resin (C).
One of these chlorinated polyolefin resins (C) may be used alone, or two or more thereof may be used in combination.

The content of the chlorinated polyolefin resin (C) is preferably 0.1 to 10% by mass, more preferably 0.3 to 9% by mass, and 0.5 to 9% by mass with respect to the total mass of the ink composition. More preferably, 0.6 to 9% by mass is even more preferable, 0.6 to 5% by mass is even more preferable, 0.6 to 3% by mass is particularly preferable, and 0.6 to 2.9% by mass is most preferable. .. When the content of the chlorinated polyolefin resin (C) is at least the above lower limit value, the adhesion of the printed layer formed from the ink composition to the substrate is enhanced. In particular, the degree of corona treatment is low and the adhesion to the olefin base material having poor wettability is enhanced. When the content of the chlorinated polyolefin resin (C) is not more than the above upper limit value, the gloss of the printed layer is further enhanced. In addition, the blocking resistance is improved while maintaining the balance of compatibility with the polyamide resin (A) and the nitrocellulose (B). In particular, blocking is less likely to occur when the substrate is bonded to a vinyl chloride base material, that is, the vinyl chloride blocking resistance is improved.

<Serosolve solvent (D)>
Examples of the cellosolve solvent (D) include methyl cellosolve (ethylene glycol monomethyl ether), ethyl cellosolve (ethylene glycol monoethyl ether), isopropyl cellosolve (ethylene glycol monoisopropyl ether), butyl cellosolve (ethylene glycol monobutyl ether), and hexyl cellosolve (). Ethylene glycol monohexyl ether), phenylcellosolve (ethylene glycol monohexyl ether), ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate and the like can be mentioned. Among these, butyl cellosolve, isopropyl cellosolve, and ethyl cellosolve are preferable from the viewpoint of increasing the adhesion of the printed layer formed from the ink composition to the substrate.
One of these cellosolve-based solvents (D) may be used alone, or two or more thereof may be used in combination.

The content of the cellosolve-based solvent (D) is 0.1 to 20% by mass, preferably 0.1 to 10% by mass, and more preferably 0.1 to 8% by mass with respect to the total mass of the ink composition. , 0.1 to 7% by mass is more preferable, 0.5 to 7% by mass is particularly preferable, and 1 to 7% by mass is most preferable. When the content of the cellosolve-based solvent (D) is at least the above lower limit value, the gloss of the print layer formed from the ink composition is enhanced. When the content of the cellosolve-based solvent (D) is not more than the above upper limit value, the drying speed of the printing layer falls within an appropriate range, and high-speed printing becomes possible.

<Organic solvent (E)>
The organic solvent (E) is an organic solvent other than the cellosolve-based solvent (D).
Examples of the organic solvent (E) include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone, and diacetone alcohol; toluene, cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, cyclopentane, and methylcyclopentane. , Hydrocarbon-based solvent such as ethylcyclopentane; Ester-based solvent such as ethyl acetate, n-propyl acetate, butyl acetate; Alcohol-based solvent such as tanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol. Solvents: propylene glycol-based solvents such as propylene glycol, dipropylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate can be mentioned.
One of these organic solvents (E) may be used alone, or two or more thereof may be used in combination.

The content of the organic solvent (E) is preferably 30 to 90% by mass, more preferably 40 to 85% by mass, still more preferably 50 to 80% by mass, based on the total mass of the ink composition. When the content of the organic solvent (E) is at least the above lower limit value, the ink composition has fluidity and is easy to handle. When the content of the organic solvent (E) is not more than the above upper limit value, when the ink composition contains the pigment described later, the pigment is less likely to settle and the dispersion stability is excellent.

<Arbitrary ingredient>
As optional components, for example, resins other than polyamide resin (A), nitrocellulose (B) and chlorinated polyolefin resin (C) (hereinafter, also referred to as "other resins"), pigments, mold release improvers, waxes. , Chelating agents, water, plastics, matting agents, antisettling agents, leveling agents, defoaming agents, pigment dispersants, silane coupling agents, UV absorbers, antioxidants, thickeners, lubricants, stabilizers, Examples include anti-blocking agents, antistatic agents, resin beads and the like.
One of these optional components may be used alone, or two or more thereof may be used in combination.

Examples of other resins include polyurethane resin, polyester resin, (meth) acrylic resin, ethylene-vinyl acetate copolymer, chlorinated ethylene-vinyl acetate copolymer, vinyl acetate resin, alkyd resin, polyvinyl chloride resin, and rosin. Examples thereof include based resins, rosin-modified maleic acid resins, terpene resins, phenol-modified terpene resins, ketone resins, cyclized rubbers, rubber chlorides, butyral, petroleum resins, and modified resins thereof.
In addition to the above, examples of other resins include alkyl celluloses such as hydroxyethyl cellulose, hydroxypropyl cellulose and carboxymethyl cellulose; cellulose acetate propionate (CAP), cellulose acetate butyrate (CAB), cellulose acetate phthalate and the like. Cellulose acetate or the like may be used.
One of these other resins may be used alone, or two or more thereof may be used in combination.

The content of the other resin is preferably 15% by mass or less, more preferably 13% by mass or less, still more preferably 10% by mass or less, based on the total mass of the ink composition.

Examples of the pigment include organic pigments and inorganic pigments.
Examples of organic pigments include azo pigments such as monoazo and condensed azo; slene pigments such as anthraquinone, perinone, perylene and thioindigo; phthalocyanine pigments such as copper phthalocyanine blue, copper phthalocyanine green and cobalt phthalocyanine blue; Examples thereof include quinacridone-based pigments; dioxazine-based pigments; isoindolinone-based pigments; pyrrolopyrrole-based pigments; aniline black; organic fluorescent pigments. One of these organic pigments may be used alone, or two or more thereof may be used in combination.
Examples of inorganic pigments include natural products such as clay, barite, mica, and talc; ferrocyanides such as navy blue, sulfides such as zinc sulfide; sulfates such as barium sulfate; chromium oxide, zinc flower, titanium oxide, and iron oxide. Oxides such as; hydroxides such as aluminum hydroxide; silicates such as calcium silicate and ultramarine; carbonates such as calcium carbonate and magnesium carbonate; carbon such as carbon black and graphite; aluminum powder, bronze powder, zinc powder and the like. , Metal powder such as silver powder; firing pigments and the like. One of these inorganic pigments may be used alone, or two or more of them may be used in combination.

The content of the pigment is preferably 45% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less, based on the total mass of the ink composition.

The mold release improving agent is not particularly limited as long as it is a compound having surface mold release property, and examples thereof include fatty acid amide, fatty acid ester, silicone, lanolin wax, surfactant, and internal mold release agent. Among these, fatty acid amide is preferable from the viewpoint of storage stability of the ink composition.

Examples of fatty acid amides include saturated fatty acid monoamides such as laurate amide, partimate amide, stearate amide, oleic acid amide, erucic acid amide, behenic acid amide, hydroxystearate amide, and N-stearyl stearate amide; N-oleyl. Unsaturated fatty acid monoamides such as partiminic acid amide, N-stearyl oleate amide, N-oleyl stearate amide; methylene bisstearate amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearate amide, ethylene bis Saturated fatty acids such as hydroxystearic acid amide, ethylene bisbechenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbechenic acid amide, N, N'-dystearyl adipic acid amide, N, N'-distearyl sevacinic acid amide. Bisamide; ethylene bisoleic acid amide, ethylene biserkaic acid amide, hexamethylene bisoleic acid amide, N, N'-diorail adipic acid amide, N, N'-dioleyl sevacinic acid amide and other unsaturated fatty acid bisamides Can be mentioned.
One of these fatty acid amides may be used alone, or two or more thereof may be used in combination.

The content of the releasability improving agent is preferably 0.1 to 10% by mass, more preferably 0.2 to 7% by mass, still more preferably 0.3 to 5% by mass, based on the total mass of the ink composition. ..

Examples of the wax include microcrystallin wax, paraffin wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, amido wax, Fishertropch wax, beeswax, carnauba wax, montan wax and the like.

The wax content is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, still more preferably 0.3 to 3% by mass, based on the total mass of the ink composition.

Examples of the chelating agent include metal chelating compounds. Examples of the metal component of the metal chelate compound include titanium, aluminum, and iron. Of these, titanium is preferred.
Examples of the titanium chelate include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanium, tetramethyl titanate, tetrahexyl titanate, tetraheptyl titanate, tetrastearyl titanate, triethanolamine titanate, and titanium acetyl. Examples thereof include acetate, titanium ethylacetacetate, titanium lactate, octylene glycol titanate, titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetate acetate, titanium dodecylbenzenesulfonate compound, and titanium phosphate ester titanium complex. Among these, titanium acetylacetonate is preferable because it has high reactivity and has a high effect of increasing the strength between the print layer and the substrate in addition to the bond strength inside the print layer.
One of these titanium chelates may be used alone, or two or more of them may be used in combination.

The content of the chelating agent is preferably 0.1 to 5% by mass, more preferably 0.2 to 4% by mass, still more preferably 0.3 to 3% by mass, based on the total mass of the ink composition.

<Manufacturing method>
The ink composition of the present embodiment contains, for example, a polyamide resin (A), a nitrocellulose (B), a cellosolve-based solvent (D) and an organic solvent (E), and if necessary, a chlorinated polyolefin resin (C) and optional components. It is obtained by mixing with one or more of them.
The mixing method of each component is not particularly limited, and each component can be mixed by various methods.

<Action effect>
In the ink composition of the present embodiment described above, in addition to the above-mentioned polyamide resin (A) and nitrocellulose (B) and the organic solvent (E) for dissolving them, the cellosolve-based solvent (D) which is a true solvent for each is used. ), It is possible to form a print layer having excellent gloss. Although it is not clear why the gloss of the printed layer is increased, the cellosolve-based solvent (D), which is the true solvent of the polyamide resin (A) and the nitrocellulose (B), adjusts the drying speed of the coating film, resulting in uneven drying. It is considered that this is because the reduction of the amount of nitrocellulose prevents the refractive index of the coating film from becoming non-uniform.
In particular, if the ink composition further contains the chlorinated polyolefin resin (C), it is possible to form a printing layer having particularly excellent adhesion to a polyolefin substrate suitable for a front printing packaging material.

<Use>
The ink composition of the present invention is used for front printing, and is used as an ink for front printing on the front side (that is, the side that does not come into contact with the product to be packaged) such as a base material used as a packaging material by gravure printing or flexographic printing. Suitable. In particular, it is most suitable as an ink for front printing on the front side of a base material by gravure printing.

The form of the base material is not particularly limited as long as it can be printed on the front, and examples thereof include a film shape, a sheet shape, and a molded body. Of these forms, the film form or the sheet form is preferable, and the film form is more preferable.

The material of the base material is not particularly limited, and is, for example, paper; polyolefin (for example, polyethylene (PE), polypropylene (PP), etc.), polyester (for example, polyethylene terephthalate (PET), etc.), polystyrene (PS), biaxially stretched polypropylene (for example). Examples thereof include plastic substrates such as OPP), unstretched polypropylene (CPP), polycarbonate (PC), polymethyl methacrylate (PMMA), polyamide (PA), polyimide (PI), and cellophane. As the base material made of these materials, one type may be used alone, or two or more types may be used together.
At least one of the front surface (front surface) and the back surface (back surface) of the plastic base material may be subjected to surface treatment such as corona discharge treatment, plasma treatment, frame treatment, solvent treatment, etc., if necessary. ..

The ink composition of the present invention is used on the front side of the above-mentioned base material, and front printing is performed by, for example, gravure printing or flexographic printing. The surface of the printed layer of the printed matter thus obtained is further subjected to a laminating process as needed to become a packaging material (package) for food packaging, daily necessities packaging, and the like. That is, the packaging material includes a base material and a printing layer provided on the front side of the base material.
Since the printed layer of the packaging material is formed from the ink composition of the present invention, it has excellent gloss. Therefore, the packaging material obtained by the present invention has a good appearance.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[Raw materials used]
The following compounds were used as the polyamide resin (A).
-A-1: Thermoplastic polyamide (manufactured by Kao Corporation, trade name "Leomide S-8200").

The following compounds were used as nitrocellulose (B).
B-1: Nitrocellulose (manufactured by Kimia Co., Ltd., trade name "RS1 / 8", type and viscosity symbol: H1 / 8).
B-2: Nitrocellulose (manufactured by Kimia Co., Ltd., trade name "RS1 / 4", type and viscosity symbol: H1 / 4).
-B-3: Nitrocellulose (manufactured by Kimia Co., Ltd., trade name "RS1 / 2", type and viscosity symbol: H1 / 2).
B-4: Nitrocellulose (manufactured by Kimia Co., Ltd., trade name "RS1", type and viscosity symbol: H1).
B-5: Nitrocellulose (manufactured by Kimia Co., Ltd., trade name "RS2", type and viscosity symbol: H2).
B-6: Nitrocellulose (manufactured by Kimia Co., Ltd., trade name "RS20", type and viscosity symbol: H20).
The type and viscosity symbol of nitrocellulose are values specified by viscosity measurement in accordance with JIS K 6703: 1995.

The following compounds were used as the chlorinated polyolefin resin (chlorinated PO resin) (C).
-C-1: Chlorinated polypropylene (manufactured by Nippon Paper Industries, Ltd., trade name "Supercron 360T").

The following compounds were used as the cellosolve-based solvent (D).
-D-1: Butyl cellosolve (manufactured by Sankyo Chemical Co., Ltd., trade name "butyl cellosolve").
-D-2: Isopropyl cellosolve (manufactured by Nippon Embroidery Co., Ltd., trade name "isopropylglycol").
-D-3: Ethyl cellosolve (manufactured by Sankyo Chemical Co., Ltd., trade name "ethyl cellosolve").
-D-4: Hexyl cellosolve (manufactured by Ando Parachemy Co., Ltd., trade name "hexyl cellosolve solvent").

The following compounds were used as the organic solvent (E).
E-1: Methylcyclohexane (MCH): Ester: i-propanol (IPA) = 5: 3: 2 (mass ratio) mixed solvent.
The ester is a mixture of ethyl acetate and n-propyl acetate.

The following compounds were used as optional components.
-Carbon Black: Made by Mitsubishi Chemical Corporation, product name "Mitsubishi Carbon Black MA100".
-Pigment Red 48: 3: Made by Dainichiseika Kogyo Co., Ltd., product name "Seika First Red 1537".
-Titanium oxide: Made by TAYCA CORPORATION, product name "Titanics JR-600A".
-Fatty acid amide: stearic acid amide (manufactured by Nippon Fine Chemical Co., Ltd., trade name "Neutron S").
-PE wax: Polyethylene wax (manufactured by Mitsui Chemicals, Inc., trade name "High Wax 220P").
-Titanium chelate: Titanium acetylacetonate (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name "Organix TC-115").

[Evaluation methods]
<Evaluation of glossiness>
Immediately after printing, the printed matter is dried with a dryer for 10 seconds, and then a gloss meter (manufactured by BYK Gardener, product name "micro-TRI-gloss") is used to achieve a 60 ° gloss (60 ° mirror gloss) on the surface of the printed layer side. The degree) was measured, and the glossiness of the printed layer was evaluated according to the following evaluation criteria. The higher the 60 ° gloss, the better the gloss.
5: 60 ° gloss is 70 or more.
4: 60 ° gloss is 60 or more and less than 70.
3: 60 ° gloss is 50 or more and less than 60.
2: 60 ° gloss is 40 or more and less than 50.
1: 60 ° gloss is less than 40.

<Evaluation of adhesion>
After drying the printed matter immediately after printing with a dryer for 10 seconds, a cellophane tape (manufactured by Nichiban Co., Ltd.) with a width of 12 mm is attached to the surface (printing surface) of the print layer and crimped with a finger, and then the cellophane tape is quickly applied. After peeling off, the state of the printed layer remaining on the base film was visually confirmed, and the adhesion of the printed layer to the base material was evaluated according to the following evaluation criteria.
5: The print layer has not migrated to the cellophane tape side at all.
4: The ratio of the area of the print layer transferred to the cellophane tape side is more than 0% and less than 5%.
3: The ratio of the area of the print layer transferred to the cellophane tape side is 5% or more and less than 20%.
2: The ratio of the area of the print layer transferred to the cellophane tape side is 20% or more and less than 50%.
1: The ratio of the area of the print layer transferred to the cellophane tape side is 50% or more.

<Evaluation of wear resistance>
After drying the printed matter immediately after printing with a dryer for 10 seconds, a load of 200 gf is used using a Gakushin type friction tester (manufactured by Tester Sangyo Co., Ltd., product name "AB-301 Gakushin type friction fastness tester"). The surface of the printed layer was rubbed 100 times back and forth with a white and black cloth (cotton No. 3-1: gold width No. 3), and a wear test was performed. The appearance of the printed layer after the wear test was visually confirmed, and the abrasion resistance of the printed layer was evaluated according to the following evaluation criteria.
5: The print layer has not moved to the gold width No. 3 side at all.
4: The ratio of the area of the print layer transferred to the gold width No. 3 side is 1% or more and less than 10%.
3: The ratio of the area of the print layer transferred to the gold width No. 3 side is 10% or more and less than 20%.
2: The ratio of the area of the print layer transferred to the gold width No. 3 side is 20% or more and less than 50%.
1: The ratio of the area of the print layer transferred to the gold width No. 3 side is 50% or more.

<Evaluation of heat resistance>
Immediately after printing, the printed matter is dried with a dryer for 10 seconds, then an aluminum foil is placed on the surface (printing surface) of the printed layer, and a heat seal tester (manufactured by Tester Sangyo Co., Ltd., product name "TP-701-C Heat") is placed on top of the aluminum foil. Using a "seal tester"), heat sealing was performed for 1 second with a load of 2 kg / cm ² . The heat seal temperature was in the range of 80 ° C to 160 ° C in increments of 20 ° C. Then, the aluminum foil was peeled off, and the heat resistance of the printed layer was evaluated according to the following evaluation criteria.
5: The print layer has not migrated to the aluminum foil side at all.
4: The ratio of the area of the print layer transferred to the aluminum foil is 1% or more and less than 10%.
3: The ratio of the area of the print layer transferred to the aluminum foil is 10% or more and less than 20%.
2: The ratio of the area of the print layer transferred to the aluminum foil is 20% or more and less than 50%.
1: The ratio of the area of the print layer transferred to the aluminum foil is 50% or more.

<Evaluation of PVC blocking resistance>
Immediately after printing, the printed matter was dried with a dryer for 10 seconds, and then superposed so that the surface (printed surface) of the printed layer and the vinyl chloride tablecloth were in contact with each other to prepare a test piece. The obtained test piece was stored for 24 hours in a constant temperature bath having a temperature of 50 ° C. and a humidity of 80% RH under a load of 1 kg / cm ² . Then, the test piece was taken out from the constant temperature bath and cooled to room temperature (20 ° C.). After cooling, the tablecloth was peeled off from the printed matter, and the vinyl chloride blocking resistance of the printed layer was evaluated according to the following evaluation criteria.
5: The print layer has not migrated to the table cloth side at all.
4: The ratio of the area of the print layer transferred to the table cloth side is 1% or more and less than 10%.
3: The ratio of the area of the print layer transferred to the table cloth side is 10% or more and less than 20%.
2: The ratio of the area of the print layer transferred to the table cloth side is 20% or more and less than 50%.
1: The ratio of the area of the print layer transferred to the table cloth side is 50% or more.

[Examples 1 to 33, Comparative Examples 1 to 6]
Polyamide resin (A), nitrocellulose (B), chlorinated polyolefin resin (C), cellosolve solvent (D), organic solvent (E), and optional components according to the formulations shown in Tables 1 to 4. Was mixed to obtain an ink composition.
As a base film, biaxially stretched polypropylene (manufactured by Futamura Chemical Co., Ltd., trade name "FOR # 25") or unstretched polypropylene (manufactured by Mitsui Chemicals Tohcello Co., Ltd., trade name "CP S #") on which one surface is corona-treated. 30 ") was used.
Using a gravure printing machine equipped with a gravure engraving plate made with a solid plate of Helio 175 lines / inch, the ink composition was printed on the corona-treated surface of the base film, and the thickness was about the same on the front side of the base film. A printed matter having a print layer of 1 μm formed was obtained.
Using the obtained printed matter, glossiness, adhesion, abrasion resistance, heat resistance and vinyl chloride blocking resistance were evaluated. The results are shown in Tables 1 to 4.
In addition, the blank in the table means that the component is not blended (blending amount 0% by mass).

As is clear from the results in Tables 1 to 3, the ink compositions obtained in each example were able to form a print layer having excellent gloss.
In particular, the inks obtained in Examples 1-9, 13-21, 23, 24, 30, 32 using nitrocellulose (B) having a type and viscosity symbol of H1 / 2, H1 or H2 as the nitrocellulose (B). The composition was able to form a printed layer having excellent wear resistance and heat resistance.
The ink compositions obtained in Examples 1 to 18, 22 to 24, 27, 28, and 31 using any of butyl cellosolve, isopropyl cellosolve, and ethyl cellosolve as the cellosolve-based solvent (D) have adhesion to a substrate. It was possible to form an excellent print layer.
On the other hand, as is clear from the results in Table 4, the printed layer formed from the ink compositions obtained in Comparative Examples 1 to 3 containing no cellosolve-based solvent (D) was inferior in gloss.
The printed layer formed from the ink composition obtained in Comparative Example 4 using nitrocellulose having a type and viscosity symbol of H20 as nitrocellulose (B) was inferior in gloss.
The printed layer formed from the ink composition obtained in Comparative Example 5 in which the content of the polyamide resin (A) was 1% by mass was inferior in gloss.
The printed layer formed from the ink composition obtained in Comparative Example 6 in which the content of nitrocellulose (B) was 30% by mass was inferior in gloss.

Claims (7)

A printing ink composition containing a polyamide resin (A), nitrocellulose (B), a cellosolve-based solvent (D), and an organic solvent (E) other than the cellosolve-based solvent (D).
The content of the polyamide resin (A) is 3 to 40% by mass with respect to the total mass of the front printing ink composition.
The content of the nitrocellulose (B) is 0.5 to 28% by mass with respect to the total mass of the front printing ink composition.
The content of the cellosolve-based solvent (D) is 0.1 to 20% by mass with respect to the total mass of the front printing ink composition.
The type and viscosity symbol defined by the viscosity measurement of nitrocellulose (B) according to JIS K 6703: 1995 are H1 / 8, H1 / 4, H1 / 2, H1 or H2, and the ink composition for printing. thing. Further containing the chlorinated polyolefin resin (C),
The ink composition for printing according to claim 1, wherein the content of the chlorinated polyolefin resin (C) is 0.6 to 9% by mass with respect to the total mass of the ink composition for printing. The ink composition for printing according to claim 2, wherein the content of the chlorinated polyolefin resin (C) is 0.6 to 2.9% by mass with respect to the total mass of the ink composition for printing. .. The ink composition for printing according to any one of claims 1 to 3, wherein the cellosolve-based solvent (D) is at least one selected from the group consisting of butyl cellosolve, isopropyl cellosolve, and ethyl cellosolve. The table printing according to any one of claims 1 to 4, wherein the content of the cellosolve-based solvent (D) is 0.1 to 7% by mass with respect to the total mass of the printing ink composition. Ink composition for. The ink composition for printing according to any one of claims 1 to 5, wherein the content of the polyamide resin (A) is 6 to 40% by mass with respect to the total mass of the ink composition for printing. thing. The ink composition for printing according to claim 6, wherein the content of the polyamide resin (A) is 6 to 19% by mass with respect to the total mass of the ink composition for printing.