JP6684948B1 - Gravure printing ink composition for styrene substrate, laminate and packaging container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide good ink stability of an ink composition, good blocking resistance when the ink composition is printed on a styrene substrate, and heat lamination strength or adhesiveness at low temperature and formability. Provided is a gravure printing ink composition for styrene base material, which has good properties. By synthesizing from an acrylic monomer containing a (meth) acrylic acid ester having a hydrophobic residue and an acrylic monomer containing a (meth) acrylic acid ester having an aliphatic hydrocarbon chain having 1 to 9 carbon atoms, Which contains the acrylic resin, the (meth) acrylic acid ester having the hydrophobic residue in 100% of the acrylic resin is 3 to 50% by mass, and the aliphatic hydrocarbon chain having 1 to 9 carbon atoms The (meth) acrylic acid ester having 50 to 97% by mass is a gravure printing ink composition for styrene substrates. [Selection diagram] None

Description

  The present invention relates to a gravure printing ink composition for styrene substrates.

  Traditionally, food trays such as prepared food containers and bento containers are printed with a design pattern on a polystyrene film, and a polystyrene sheet foamed from the printed film or a polystyrene sheet excellent in impact resistance is laminated by thermocompression bonding. (Hereinafter, also referred to as "thermal lamination"). As the printing ink composition at this time, one containing an acrylic resin or a styrene-acrylic copolymer resin as a main component is known.

  Patent Document 1 discloses a styrene film for thermal lamination containing an acrylic resin, a binder resin containing a cellulose acetate butyrate (CAB) resin and / or a cellulose acetate propionate (CAP) resin, a pigment, and a solvent. A printing ink composition for use in printing, wherein the acrylic resin is synthesized from an acrylic monomer containing methyl methacrylate and butyl methacrylate, is dissolved or dispersed in an alcohol-based or ester-based organic solvent, and the CAB resin is , A CAP resin having a number average molecular weight of 60,000 or less and a number average molecular weight of 60,000 or less, a printing ink composition for a styrene film for thermal lamination has been proposed, and while maintaining storage stability of the ink, It is intended to provide an ink having a good blocking property.

  However, according to Patent Document 1, in the evaluation of the preservability of the ink, the acrylic resin and CAB and CAP are good results in both Examples and Comparative Examples. Although it is considered that any of them has no effect on the ink storability, it has not been studied at all that the acrylic resin used for thermal lamination at a lower temperature has sufficient lamination strength even at a low temperature.

  The only one having an inferior storage stability of the ink was a combination of an acrylic resin and a nitrocellulose resin (Comparative Example 6), which was obtained by nitrating the hydroxyl groups of cellulose with nitric acid. To be The average degree of polymerization is about 35 to 480, and the degree of biomass changes depending on the degree of substitution with the nitro group, but about 50% by mass is the biomass-derived resin.

  Since the above cellulose-based resin is effective as a biomass material, it can be said that it is an excellent resin in terms of environment. Therefore, it can be said that increasing the amount used is more environmentally friendly. As described above, in Patent Document 1, it is clear that when the acrylic resin and the nitrocellulose resin to be used are used together, the ink storability is inferior, and the use of the resin in combination is not considered, Neither has it been studied to have sufficient laminate strength even at low temperatures.

  In addition, paper containers, metal containers, aluminum containers, plastic containers, and the like are used as packaging containers for beverages, foods such as prepared foods and bentos, and cosmetics. A laminate or film made of a thermoplastic resin that is provided with cosmetic properties and functionality is attached. These laminates and films are, for example, a polystyrene film (hereinafter also referred to as "PS film") molded from polystyrene resin as a body-wrap label such as a bottle made of polyethylene terephthalate (hereinafter also referred to as "PET bottle"). ) Or polyethylene terephthalate (hereinafter, also referred to as “PET film”) is used as the base material layer. In particular, for PET bottles, a shrinkable PET film, a stretch PET film and a shrinkable PS film that follow the shape of the PET bottle are used.

  However, it is known that the PS film is inferior in solvent resistance, and the PS film is deteriorated by the solvent in the ink composition and becomes white (the film whitening property is inferior). Therefore, it is necessary to use a solvent composition that does not deteriorate the PS film. However, if a resin suitable for the PET film is used, the solvent composition of the PS film is inferior in resin solubility, and thus the fluidity of the ink composition is low. However, there is a problem that printability such as transferability and swimming is deteriorated, and moldability upon shrink molding is deteriorated. On the other hand, in order to make a solvent composition applicable to a resin suitable for a PET film, it is necessary to use an ester solvent, but it cannot be applied immediately because it deteriorates the PS film.

  In Patent Document 2, in a printing ink composition for shrink packaging mainly composed of a pigment, a resin component and a solvent component, as the resin component, an acrylic resin 70 to 90% by mass and nitrocellulose 10 satisfying the following condition A are used. -30% by mass (both calculated as solid content) and 50-70% by mass of a lower alcohol having 1 to 4 carbon atoms as a solvent component with respect to all solvent components. 50 to 70% by mass of a linear alkyl ester compound having 3 to 8 carbon atoms of (meth) acrylic acid, 5 to 15% by mass of a hydroxyalkyl ester of (meth) acrylic acid, and 15 to 45% by mass of another copolymerizable vinyl monomer. Obtained by copolymerizing a monomer component consisting of 30,000, a molecular weight of 30,000 to 100,000 and a hydroxyl value of 20 to 110 mg KO. / G acrylic resin), and has sufficient printability without any deterioration of the film when applied to shrinkable PS film and shrinkable PET film. The present invention provides an ink composition having excellent adhesiveness to the ink and good whitening resistance of the ink film against shrinkage of the film.

  Patent Document 3 discloses a coating agent composition containing a pigment and a resin component applied to the surface of a plastic label attached to the container, the surface being in contact with the container, wherein the resin component is mainly a weight average molecular weight of 8000. To 25,000 acrylic resin (A) and nitrified cotton (B), the ratio of the former (A) / the latter (B) (weight ratio) = 70/30 to 95/5 A composition has been proposed, and a coating agent composition for a plastic label, which has excellent properties in all aspects of high-speed printing suitability, adhesion, ink cracking resistance, alkali resistance and hot water resistance, for PET films and OPS films. It is provided.

  Patent Document 4 discloses a printing ink containing an acrylic resin, a cellulosic resin, and a solvent containing a low-volatile solvent having a specific evaporation rate of 20 to 100 in an amount of 0.1 to 30% by weight based on all the solvents. A printing ink that has been proposed and has excellent printability due to its excellent leveling properties, long-term ink stability, and also excellent properties such as adhesion to plastic films, heat resistance, and blocking resistance. Is provided.

  However, in Patent Documents 2 and 3, although a lower alcohol having 1 to 4 carbon atoms is used as a main solvent, nitrocellulose, which is a resin component, tends to be deposited, so that there is a problem that adhesion is poor.

  Patent Document 4 suppresses the precipitation of a cellulosic resin such as nitrocellulose and improves the leveling property by using a specific amount of a low-volatile solvent. However, what is used as a main solvent is Since it is an ester solvent and contains a large amount of the solvent, there is a possibility that a PS film having poor solvent resistance may be deteriorated (whitened), or holes may be opened or torn during printing.

Japanese Patent No. 5853832 JP, 2004-175858, A JP, 2004-21110, A JP, 2008-163231, A

  Therefore, the present invention has good ink stability of the ink composition, good blocking resistance when the ink composition is printed on a styrene substrate, and good heat lamination strength or adhesion at low temperature and moldability. An object is to provide a good gravure printing ink composition for a styrene substrate.

  The present inventors synthesize from an acrylic monomer containing a (meth) acrylic acid ester having a hydrophobic residue and an acrylic monomer containing a (meth) acrylic acid ester having an aliphatic hydrocarbon chain having 1 to 9 carbon atoms. It was found that the above-mentioned object can be achieved by using a styrene-based gravure printing ink composition containing an acrylic resin thus obtained, and the present invention has been completed.

That is, the present invention is
(1) At least one acrylic monomer selected from lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate, and an acrylic resin obtained by synthesizing methyl methacrylate and butyl methacrylate. Then
3% to 50% by mass of at least one acrylic monomer selected from lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate in 100% of the acrylic resin , and methyl methacrylate. And a total amount of butyl methacrylate of 50 to 97% by mass, a gravure printing ink composition for styrene base material,
(2) further contains a fiber resin,
The ratio of the solid content weight (A) of the acrylic resin and the solid content weight (B) of the fibrous resin is A / B = 100/0 to 50/50. Gravure printing ink composition for styrene base material,
(3) The gravure printing ink composition for a styrene substrate according to (1) or (2), which further contains a pigment.
(4) The styrene-based gravure printing ink composition according to (3), wherein the pigment is at least one selected from an inorganic pigment and an organic pigment.
(5) A laminate having a printed layer formed on at least one of the styrene base materials using the styrene base gravure printing ink composition according to any one of (1) to (4).
(6) A packaging container produced by using the laminate according to (5),
It is about.

  According to the present invention, the ink stability of the ink composition is good, the blocking resistance is good when the ink composition is printed on a styrene substrate, and the thermal lamination strength or adhesion at low temperature and the moldability are good. A good gravure printing ink composition for a styrene substrate can be provided.

  Hereinafter, modes for carrying out the present invention will be described in detail. It should be noted that the present embodiment is merely one mode for carrying out the present invention, and the present invention is not limited to the present embodiment, and various modifications and embodiments without departing from the scope of the present invention Is possible.

  In the following description, (meth) acryl or (meth) acrylate means acryl and methacryl, acrylate and methacrylate, respectively.

  The gravure printing ink composition for a styrene substrate of the present invention (hereinafter, also simply referred to as “ink composition” or “ink”) comprises an acrylic monomer containing a (meth) acrylic acid ester having a hydrophobic residue, and carbon. It is preferable to contain an acrylic resin obtained by synthesizing from an acrylic monomer containing a (meth) acrylic acid ester having an aliphatic hydrocarbon chain of the number 1 to 9.

  The acrylic resin used in the gravure printing ink composition for a styrene substrate of the present invention comprises a (meth) acrylic acid ester having a hydrophobic residue as an acrylic monomer component, and an aliphatic hydrocarbon chain having 1 to 9 carbon atoms. It is preferable that it is obtained by synthesizing (meth) acrylic acid ester having By using an acrylic resin as an acrylic monomer component containing a (meth) acrylic acid ester having a hydrophobic residue, the ink stability of the ink composition is good, and when the ink composition is printed on a styrene substrate In addition, the blocking resistance is good, and the thermal lamination strength or adhesion at low temperature and the moldability are good.

  The acrylic resin 100% preferably contains (meth) acrylic acid ester having a hydrophobic residue in an amount of 3 to 50% by mass, more preferably 5 to 40% by mass, and even 10 to 30% by mass. More preferable. If it is less than 3% by mass, the suitability for lamination at low temperature may not be obtained. If it exceeds 50% by mass, the solubility in alcohol is reduced and the deterioration resistance to the styrene base material may be poor (the base material may be split or torn).

  The acrylic resin 100% preferably contains 50 to 97% by mass of the (meth) acrylic acid ester having an aliphatic hydrocarbon chain having 1 to 9 carbon atoms, more preferably 60 to 95% by mass, It is more preferable to contain 70 to 90 mass%. If it exceeds 97% by mass, the suitability for lamination at low temperatures may not be obtained.

  Examples of the hydrophobic residue of the (meth) acrylic acid ester having a hydrophobic residue include an aliphatic hydrocarbon group having 10 or more carbon atoms, an alicyclic hydrocarbon group having 10 or more carbon atoms, and an aromatic compound having 6 or more carbon atoms. Examples thereof include a group monocyclic hydrocarbon group, a condensed polycyclic aromatic hydrocarbon group having 10 or more carbon atoms, a heteromonocyclic group, a condensed heterocyclic group, and a spiro hydrocarbon group.

  Examples of the aliphatic hydrocarbon group having 10 or more carbon atoms include an alkyl group, an alkenyl group, an alkadienyl group, an alkatrienyl group, an alkynyl group, etc., and preferably 10 or more and 40 or less carbon atoms. It is more preferably 20 or less and more preferably 12 or more and 18 or less.

  Examples of the alkyl group having 10 or more carbon atoms include a decyl group, an undecyl group, a lauryl group, a tridecyl group, a myristyl group, a pentadecyl group, a palmityl group, a heptadecyl group, a stearyl group, a nonadecyl group, and an eicosyl group. More preferred are groups, myristyl groups, palmityl groups, stearyl groups and the like.

  As the alkenyl group having 10 or more carbon atoms, a decenyl group, an undecenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, a hexadecenyl group, an oleyl group, a linoleyl group, a nonadecenyl group, an eicosenyl group, a triacontenyl group, 2, 4,6-trimethylheptenyl group, 2,4,6,8-tetramethylnonenyl group, 2-n-butyltetradecenyl group and the like can be mentioned, and among them, pentadecenyl group, oleyl group, linoleyl group and the like can be mentioned. More preferable.

  Examples of the alkynyl group having 10 or more carbon atoms include a decynyl group, an undecynyl group, a dodecynyl group, a tridecynyl group, a tetradecynyl group, a pentadecynyl group, a hexadecynyl group, a heptadecynyl group, an octadecynyl group, a nonadecynyl group, and an eicosinyl group, and among them, pentadecynyl group. A group and the like are more preferable.

  Examples of the alicyclic hydrocarbon group having 10 or more carbon atoms include a cycloalkyl group, a cycloalkenyl group, an isobornyl group, an adamantyl group, a dicyclopentanyl group and a dicyclopentenyl group, and the number of carbon atoms is 10 or more and 20 or less. Is preferable, 10 or more and 16 or less is more preferable, and 10 or more and 12 or less is further preferable. Of these, an isobornyl group, an adamantyl group, a dicyclopentanyl group, a dicyclopentenyl group and the like are more preferable.

  Examples of the aromatic monocyclic hydrocarbon group having 6 or more carbon atoms include phenyl group, benzyl group, tolyl group, xylyl group, methylphenyl group, butylphenyl group, octylphenyl group, nonylphenyl group and 3,5-dimethylphenyl group. A biphenyl group, a terphenyl group, a cumyl group, a phenoxy group, etc., and preferably has 6 or more and 30 or less carbon atoms, more preferably 6 or more and 20 or less, and 6 or more and 18 or less. More preferable. Of these, a phenyl group, a benzyl group, a methylphenyl group, a butylphenyl group, a phenoxy group and the like are more preferable.

  Examples of the condensed polycyclic aromatic hydrocarbon group having 10 or more carbon atoms include naphthyl group, anthracenyl group, phenanthryl group, naphthylmethyl group, anthracenylmethyl group, anthracenylethyl group, etc., and have 10 or more carbon atoms. It is preferably 30 or less, more preferably 10 or more and 20 or less, still more preferably 10 or more and 14 or less. Of these, a naphthyl group and the like are more preferable.

  Examples of the heteromonocyclic group include a pyrrolyl group, an imidazolyl group, a pyrrolidinyl group, an imidazolidinyl group, an indolyl group, a morpholinyl group, a thiazolyl group, a thienyl group, and a furyl group. Examples of the condensed heterocyclic group include a benzothienyl group and a benzooxathiynyl group.

  Examples of the (meth) acrylic acid ester having an aliphatic hydrocarbon chain having 1 to 9 carbon atoms include an alkyl group, an alkenyl group, an alkadienyl group, an alkatrienyl group, an alkynyl group and the like, and among them, a methyl group, an ethyl group. Group, propyl group, n-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group and the like are preferable, and methyl group, ethyl group, propyl group, n-butyl group, pentyl group, etc. Is more preferable. These may be used alone or in combination of two or more. If a branched alkyl group such as an isobutyl group is included, the adhesiveness at low temperatures may be poor, so it is desirable not to include it.

  The weight average molecular weight of the acrylic resin is preferably 20,000 to 200,000, more preferably 30,000 to 110,000. If the weight average molecular weight of the acrylic resin is less than 20,000, the cohesive force with the styrene base material tends to decrease during thermal lamination, and blister tends to occur during molding, which is not preferable. However, when it exceeds 200,000, the resin viscosity becomes high. The weight average molecular weight can be evaluated as a polystyrene reduced molecular weight using gel permeation chromatography (GPC).

  The fibrous resin used in the gravure printing ink composition for a styrene substrate of the present invention includes cellulose acetate butyrate (hereinafter also referred to as “CAB”) and cellulose acetate propionate (hereinafter also referred to as “CAP”). , And at least one selected from nitrocellulose resins.

The cellulose acetate butyrate and cellulose acetate propionate can be obtained by reacting cellulose with a suitable organic acid and / or acid anhydride. The CAB is obtained by esterifying cellulose with acetic acid and butyric acid, followed by hydrolysis. Generally, acetylation is 2 to 29.5% by mass, butyrylation is 17 to 53% by mass, hydroxyl group is 0.8 to 4.8% by mass, and biomass degree is about 50% by mass. The CAP is obtained by esterifying cellulose with acetic acid and propionic acid and then hydrolyzing it. Generally, acetylation is 0.6 to 2.5% by mass, propionylation is 42.5 to 46% by mass, hydroxyl group is 1.8 to 5% by mass, and biomass degree is about 50% by mass.
The nitrocellulose resin is obtained by nitrating the hydroxyl groups of cellulose with nitric acid. The average degree of polymerization is about 35 to 480, and the degree of biomass changes depending on the degree of substitution with nitro groups, but about 50% by mass is derived from biomass.

  The ratio of the solid content weight (A) of the acrylic resin and the solid content weight (B) of the fiber resin is preferably A / B = 100/0 to 50/50, and 95/5 to 65 / It is more preferably 35, and even more preferably 90/10 to 70/30. Since the laminating strength at low temperature is improved, the thermal laminating strength is less likely to decrease even if the solid content weight of the fiber-based resin is increased. The number average molecular weight of CAB or CAP is preferably 60,000 or less, more preferably 10,000 to 30,000. The lower the number average molecular weight, the lower the resin viscosity, but the desired blocking resistance does not decrease. When the number average molecular weight exceeds 60,000, the resin viscosity becomes high, the transfer of the ink is obstructed during printing, and the printed matter has poor design. In particular, when the nitrocellulose resin is contained in the fiber resin, the pigment dispersibility and the blocking resistance can be improved.

  The styrene-based gravure printing ink composition for a styrene substrate of the present invention may optionally contain other resins in addition to the above acrylic resin and fiber resin. As other resins, polyurethane urea resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, acrylic resin, ethylene-vinyl acetate copolymer resin, chlorinated olefin resin, alkyd resin, vinyl acetate resin, Rosin resin (rosin, cured rosin, polymerized rosin, rosin ester, rosin-modified maleic acid resin, etc.), ketone resin, polybutyral resin, cyclized rubber resin, chlorinated rubber resin, petroleum resin, olefin resin, polyester resin , Polylactic acid resin and the like.

  The total resin content of the acrylic resin, the fiber resin, and the other resin is preferably 3 to 50% by mass, and preferably 5 to 30% by mass, in terms of solid content in the ink composition. It is more preferable that the amount is 10 to 20% by mass. When the content of the resin is less than 3% by mass, the film forming property of the ink composition is poor, and when it is more than 50% by mass, the fluidity of the ink composition is poor and the manufacturability of the ink composition is poor. When another resin is used in combination, it is preferably 30% by mass or less of the total resin solid content in the ink composition. In particular, when a nitrocellulose resin is used in combination, it is preferably 10% by mass or less based on the total resin solid content in the ink composition. If it is more than 10% by mass, the adhesion to a styrene substrate and the laminate strength will be reduced.

The styrene-based gravure printing ink composition of the present invention may contain a pigment. The pigment is preferably an inorganic pigment and / or an organic pigment.
Examples of the inorganic pigment include titanium dioxide, iron oxide, barium sulfate, zinc oxide, calcium carbonate, silica, aluminum paste, pearl pigment, carbon black, brass and mica. Carbon black may be classified as an inorganic pigment, but it is excluded in the present invention. Of these, at least one selected from titanium dioxide, iron oxide, and aluminum paste is preferable.
Examples of the organic pigments include monoazo pigments, disazo pigments, condensed azo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, Examples thereof include thioindigo pigments, quinofuraron pigments, dioxazine pigments, pyrrolopyrrole pigments, nitro pigments, nitroso pigments and aniline black. Carbon black is also preferable. Of these, at least one selected from monoazo pigments, disazo pigments, phthalocyanine pigments, and carbon black is preferable. The addition amount of these pigments is appropriately determined according to the concentration, coloring power, and hiding power of the ink composition, but it is preferable that the content of the pigment is 0.1 to 50% by mass, and the content is 5 to 45% by mass. Is more preferable, and it is further preferable that the content is 10 to 40% by mass. In particular, the content of the inorganic pigment is preferably 20 to 40% by mass, and the content of the organic pigment is preferably 10 to 30% by mass.

  As the solvent component used in the printing ink composition for a styrene substrate of the present invention, an alcohol solvent having 1 to 4 carbon atoms is preferable. For example, methanol, ethanol, isopropanol, normal propanol, butanol, isobutanol, tert-butanol and the like can be mentioned, and among them, isopropanol, normal propanol, butanol and isobutanol are more preferable.

  The alcohol solvent having 1 to 4 carbon atoms is preferably in the range of 40 to 70% by mass in 100% by mass of the solvent component when used for thermal lamination. If the amount is less than 40% by mass, in addition to poor adhesion, the styrene substrate may be damaged (deteriorated) and whiten, or if it is a film, holes may be opened during printing or the film may be torn. In that case, there is a risk that holes may be opened or cracked during molding. If the amount is more than 70% by mass, the solubility of the acrylic resin or the fiber-based resin may decrease, and the resin solution may become cloudy or these resins may precipitate. Moreover, when it is used for shrink molding, it is preferably in the range of 60 to 80 mass% in 100 mass% of the solvent component. If the amount is less than 60% by mass, in addition to poor adhesion, the styrene substrate may be damaged (deteriorated) and whiten, or if it is a film, holes may be opened during printing, or the film may tear. In that case, there is a risk that holes may be opened or cracked during molding. If it is more than 80% by mass, the solubility of the acrylic resin or the fibrous resin is lowered, and the resin solution may become cloudy or these resins may be precipitated.

Further, as the solvent component, in addition to the alcohol solvent having 1 to 4 carbon atoms, a solvent usually used for gravure ink can be used, and a solvent in which the acrylic resin is dissolved or dispersed in the solvent is preferable. Solvents used for gravure ink include aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Ketone solvents, ester solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol Dimethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monop Examples include glycol solvents such as pill ether and propylene glycol monobutyl ether, and esterified products thereof.The esterified products are mainly those which are acetated, for example, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene. Examples thereof include glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. These may be used alone or in combination of two or more. Above all, it is more preferable that the ester solvent is contained in an amount of 30% by mass or more based on 100% by mass of the solvent component.
The solvent component including the alcohol solvent having 1 to 4 carbon atoms in the ink composition is preferably in the range of 30 to 95% by mass. If it is less than 30% by mass, the solid content increases and the fluidity is lost. When it is more than 95% by mass, the viscosity becomes low and the pigment tends to settle. Above all, it is preferable not to include the aromatic hydrocarbon solvent in consideration of the printing work environment.

  The styrene-based gravure printing ink composition for a styrene base of the present invention contains, if necessary, an anti-friction agent, an anti-blocking agent, a pigment dispersant, an antistatic agent, a lubricant, a cross-linking agent, a defoaming agent, and a drying control agent. , A plasticizer, a tackifier, an adhesion improver, a leveling agent, an antioxidant and the like can be added.

  As the pigment dispersant, a polyester-based pigment dispersant usually used for gravure ink can be used. Examples of commercially available products include Azisper PB821, Ajisper PB822, Ajisper PB824, Ajisper PB881 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), Solsperse 24000, Solsperse 56000 (manufactured by Nippon Lubrizol Co., Ltd.) and the like. Among them, a basic group-containing polyester polymer dispersant can be preferably used. The content of the pigment dispersant is usually preferably in the range of 1 to 200 parts by mass, and more preferably 1 to 60 parts by mass with respect to 100 parts by mass of all the pigments in the ink composition. When the content of the pigment dispersant is less than 1 part by mass, the ink composition may be precipitated or may be significantly thickened (the pigment dispersibility may be lowered). Although it may be contained in an amount of more than 200 parts by mass, it may not be effective for further improving the pigment dispersion.

  As the lubricant, polyethylene wax, polypropylene wax, PTFE wax, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, montan wax, carnauba wax, shellac wax, amide wax, organic polymer, beeswax, and mixed wax thereof are preferable. Of these, polyethylene wax and polypropylene wax are more preferable.

  The styrene-based gravure printing ink composition of the present invention is an acrylic resin, a fiber resin, a pigment, and optionally other resins and various additives, in the presence of a solvent, uniformly mixed, dispersed. Can be manufactured by a known method. When the pigment is dispersed, it can be produced by making the aggregated pigment into fine particles to an average particle diameter of about 0.01 to 1 μm to obtain a dispersion.

For the mixing and dispersing, various agitators or dispersers can be used, and a disper, a ball mill, a sand mill, an attritor, a bead mill, a roll mill, a pebble mill, a paint shaker, an agitator, a Henschel mixer, a colloid mill, a pearl mill, an ultrasonic homogenizer, a wet type. Examples include jet mills, kneaders, homomixers, and the like. The manufacturing method when using the bead mill is not particularly limited, but it may be a pass method or a circulation method, and the pass method may be a multiple pass method in which the dispersion is passed a plurality of times.
The average particle size of the organic pigment in the dispersion includes the bead mill's bead separation mechanism, bead type, bead particle size, bead filling rate, shape and number of stirring blades, rotation speed, dispersion viscosity, discharge rate, premix time, etc. Can be adjusted accordingly.
Coarse particles and bubbles in the ink composition can be removed by a known filter, centrifuge or the like.

The viscosity of the ink composition is preferably in the range of 10 to 1,000 mPa · s / 25 ° C. If it is less than 10 mPa · s, the viscosity tends to be too low and the pigment tends to settle, and if it is more than 1,000 mPa · s, the fluidity is poor and the ink production may be hindered and filling into the container is difficult. Becomes In this case, it can be measured using a commercially available viscometer such as a Brookfield type viscometer or a cone plate type viscometer.
The solid content in the ink composition is preferably in the range of 2 to 80% by mass. If it is less than 2% by mass, the coating amount at the time of printing is not sufficient, and if it exceeds 80% by mass, the fluidity is poor and it becomes difficult to form an ink.
The ink composition is appropriately diluted with a diluting solvent to a viscosity and a concentration suitable for printing conditions before printing.

The diluting solvent can adjust the viscosity and the concentration of the ink composition, and an alcohol-based solvent is particularly preferable. Examples of commercially available products include AC301 solvent (containing toluene), AC372 solvent (non-toluene system), AC341 solvent (non-toluene system) (all of which are manufactured by Tokyo Ink Co., Ltd.).
Of these, a non-toluene-based diluting solvent is preferable in view of the printing work environment.

  When the ink composition is used for printing, the viscosity is Zahn cup No. No. 3 (manufactured by Sogo Co., Ltd.), preferably at a temperature of 25 ° C. for 13 to 25 seconds. If it is less than 13 seconds, it is easy to swim, and if it is more than 25 seconds, the transferability during printing becomes poor.

  At the time of printing, a curing agent can be added to the ink composition, if necessary. For example, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 4,4′-dicyclohexyl diisocyanate, pentane-1,5 -Polyisocyanate curing agents such as aliphatic diisocyanates such as diisocyanate (Stavio PDI) and modified products thereof such as trimethylolpropane trimer, isocyanurate, buret, and allophanate. These may be used alone or in combination of two or more.

  It is preferred that the gravure printing ink composition for a styrene substrate of the present invention is applied to at least one of the styrene substrates to form a laminate having a printing layer. It is more preferable that the styrene base material is one that can be applied to a thermal laminate and one that can be applied to a shrink. When it is applicable to thermal lamination, it can be a thermal laminate laminate having a laminate layer on the printed layer.

  As the styrene base material, any material can be used as long as it can be applied to thermal lamination, but a stretched polystyrene (OPS) film, a non-stretched polystyrene (CPS) film, and a polystyrene sheet (PS sheet) are more preferable. The thickness of the styrene base material in this case is not particularly limited as long as it is within a range that does not impair printability, windability, etc., but is preferably 5 to 500 μm, more preferably 10 to 50 μm. Also, untreated ones can be selected, but in order to improve the adhesion of the printed layer or laminated layer on the printed surface, corona treatment, low temperature plasma treatment, flame treatment, solvent treatment, coat treatment, etc. are performed or pre-treated. You can choose what you want. Any material can be used as long as it can be applied to shrink, but a shrink PS film is more preferable. In this case, the thickness of the styrene base material is not particularly limited as long as it does not hinder the printability, the winding suitability, etc., but is preferably 5 to 100 μm, more preferably 10 to 50 μm. The styrene base material may be untreated, but is it subject to corona treatment, low-temperature plasma treatment, flame treatment, solvent treatment, coating treatment, etc. to improve the adhesion of the printed layer or laminated layer on the printed surface? , You can select one that has been applied in advance.

  The print layer is preferably formed by coating by a gravure printing method in terms of high quality and high productivity. In particular, it is more preferably created by a gravure printing method using a multicolor gravure printing machine. The printing layer is printed by a gravure printing machine using a corrosive plate called a laser plate or an engraving plate engraved with diamond needles. The printing speed is usually in the range of 30 to 350 m / min.

  The laminate layer is preferably provided on the print layer. The laminating layer is, for example, thermal laminating by thermocompression bonding (laminator) of a heating roll, dry laminating with an adhesive containing resin (adhesive film), non-solvent laminating, wet laminating, extrusion laminating by melting resin, or adhering. The resin is applied onto the printed layer by bonding with an agent or the like. In particular, heat lamination and extrusion lamination are more preferable. Also, two or more layers of resin may be layered and extrusion laminated. In this case, the resins used may be the same or different resins.

  The resin used for the heat lamination is preferably polystyrene, polypropylene, polyethylene or polyester resin. Among them, from the viewpoint of versatility, general purpose polystyrene (GPPS), high impact polystyrene (HIPS), expanded styrene paper (PSP), heat resistant PSP. Are preferred. As a specific example of laminating by heat lamination, when laminating a HIPS sheet, PSP or heat resistant PSP with the styrene film, the styrene film side is heated with a heating roll, and the heating roll and the HIPS sheet, PSP or heat resistant PSP side are laminated. The HIPS sheet, PSP or heat-resistant PSP and the styrene film are pressed by the arranged nip rolls to thermally bond them. In the present invention, the temperature at which the temperature is low when laminating by thermal lamination is a temperature lower than a general thermal laminating temperature, that is, a temperature having sufficient laminating strength even if thermal laminating is performed at about 130 ° C. or less. .

  The resin used for the extrusion lamination is polystyrene resin, ethylene-vinyl acetate copolymer resin, ethylene- (meth) acrylic acid copolymer resin, ethylene- (meth) acrylic acid methyl copolymer resin, ethylene- (meth) acrylic acid ethyl ester. Copolymer resin, ethylene-vinyl alcohol copolymer resin, polyamide resin, polyvinyl alcohol resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyester acrylate resin, epoxy acrylate resin, urethane acrylate resin, polyether acrylate resin, diallyl phthalate resin, It is preferable to contain at least one of a nitrocellulose resin, a polyurethane resin, a polyester resin, an acrylic resin, a chlorinated polyolefin resin, a vinyl chloride-vinyl acetate copolymer, and a rosin resin. Further, the same kind of resin as the base material or a different kind of resin may be used. As a specific example of laminating by extrusion laminating, an anchor coating agent is applied to the printed layer surface of the styrene film, if necessary, and a resin film (polyethylene, polypropylene, etc.) that has been melted by heating is formed between the film made of the resin and the styrene film. It is extruded in a thin film form between the printing layer surfaces, pressure bonded and laminated.

  The thickness of the laminate layer is preferably 100 μm to 5 mm, and more preferably 200 μm or more, and more preferably 300 μm or more for forming into a rigid container or a container or tray formed by deep drawing. Is more preferable. In addition, a foamed thermoplastic resin sheet having a thickness of about 5 mm is preferable from the viewpoint of lightness and heat insulation property, and particularly, expanded polypropylene (EPP), expanded polyethylene (EPE), and expanded polystyrene (EPS) are preferable.

  The prepared laminate is for packaging, food preservation, agriculture, civil engineering, fishery, automobile interior / exterior, marine, daily necessities, building interior / exterior, residential equipment, medical / medical equipment, pharmaceutical. It can be used for home appliances, furniture, stationery / office supplies, sales promotion, commercial, electrical and electronic industries, etc.

  A packaging container produced by using the laminate of the present invention is preferable. Used as packaging such as rocket, triangular pack, gable top, brick, shibori, cup, tray, bottle, brick, container, box, case, number, cover, lid, cap, label, in-mold cup. Any of the well-known forms may be used.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the examples and comparative examples, "part" means "part by mass" and "%" means "% by mass".

<Example 1>
Phthalocyanine-based pigment (CI Pigment Blue 15: 4) 10 parts, pigment dispersant (Azisper PB824, manufactured by Ajinomoto Fine-Techno Co., Ltd.) 1 part, acrylic resin solution 1 40 parts, CAP varnish 1 12 parts, ethyl acetate 9 .2 parts, n-propyl acetate 9.2 parts, and isopropyl alcohol 18.6 parts were mixed and stirred, and then dispersed by a paint shaker to obtain ink No. 100 parts of 1 were obtained. Similarly, according to the formulations of Tables 1 to 14 and Tables 29 to 33, the ink Nos. Of Examples 2 to 270 and Comparative Examples 1 to 86 were obtained. 2 to 270, No. 541-626 were produced.

<Example 271>
Phthalocyanine-based pigment (CI Pigment Blue 15: 4) 10 parts, pigment dispersant (Azisper PB824, manufactured by Ajinomoto Fine-Techno Co., Ltd.) 1 part, acrylic resin solution 1 40 parts, CAP varnish 1 12 parts, wax (polyethylene) 5 parts of wax, manufactured by Mitsui Chemicals, Inc., 2 parts of ethyl acetate, 2 parts of n-propyl acetate, and 28 parts of isopropyl alcohol are mixed and stirred, and then dispersed with a paint shaker to prepare ink No. 100 parts of 271 were obtained. Similarly, according to the formulations of Tables 15 to 28 and Tables 33 to 37, ink Nos. Of Examples 272 to 540 and Comparative Examples 87 to 174 were used. 272-540, No. 627-714 were produced.

The materials used were as follows.
The weight average molecular weight was evaluated as a polystyrene reduced molecular weight using gel permeation chromatography (GPC).
Acrylic resin solution 1: a resin obtained by synthesizing 20% by mass of lauryl methacrylate, 30% by mass of methyl methacrylate, and 50% by mass of butyl methacrylate by a conventional method in 100% by mass of resin, isopropyl alcohol / ethyl acetate = 1/1 mixed solvent, solid content 40%, weight average molecular weight 60,000
Acrylic resin solution 2: resin obtained by synthesizing 20 mass% of stearyl methacrylate, 30 mass% of methyl methacrylate, and 50 mass% of butyl methacrylate in 100 mass% of the resin by a conventional method, isopropyl alcohol / ethyl acetate = 1/1 mixed solvent, solid content 40%, weight average molecular weight 60,000
Acrylic resin solution 3: a resin obtained by synthesizing 5% by mass of stearyl methacrylate, 35% by mass of methyl methacrylate, and 60% by mass of butyl methacrylate in 100% by mass of resin by a conventional method, isopropyl alcohol / ethyl acetate = 1/1 mixed solvent, solid content 40%, weight average molecular weight 60,000
Acrylic resin solution 4: Resin made by a conventional method of synthesizing 95% by mass of stearyl methacrylate and 5% by mass of methyl methacrylate in 100% by mass of resin, isopropyl alcohol / ethyl acetate = 1/1 mixed solvent, solid content 40%, weight average molecular weight 60,000
Acrylic resin solution 5: 100% by weight of resin in 100% by weight, resin obtained by synthesizing lauryl methacrylate by a conventional method, isopropyl alcohol / ethyl acetate = 1/1 mixed solvent, solid content 40%, weight average molecular weight 60,000
Acrylic resin solution 6: Resin obtained by synthesizing 35% by weight of methyl methacrylate and 65% by weight of butyl methacrylate in a conventional method in 100% by weight of resin, isopropyl alcohol / ethyl acetate = 1/1 mixed solvent, solid content 40%, weight average molecular weight 50,000
Acrylic resin 7: 100% by mass of resin, 24% by mass of methyl methacrylate, 66% by mass of butyl methacrylate and 10% by mass of 2-hydroxyethyl methacrylate are synthesized by a conventional method, solid content is 100%, The weight average molecular weight was 60,000 and the hydroxyl value was 40 mgKOH / g.
Acrylic resin 8: Resin obtained by synthesizing methyl methacrylate contained in 17% by mass, butyl methacrylate contained in 60% by mass, and 2-hydroxyethyl methacrylate contained in 23% by mass in a resin of 100% by mass, solid content 100%, The weight average molecular weight was 12,000 and the hydroxyl value was 92 mgKOH / g.
Acrylic resin 9: ARUFON UC-3000 (manufactured by Mitsubishi Chemical Co., Ltd.), solid content 100%, weight average molecular weight 10,000, acid value 74 mgKOH / g, Tg 65 ° C.).
CAP varnish 1: Created with the following formulation CAP varnish 2: Created with the following formulation CAB Niss 1: Created with the following formulation CAB Niss 2: Created with the following formulation Phthalocyanine pigment: Pigment Blue 15: Four
Monoazo pigment: Pigment Red 48: 3
Disazo pigment: Pigment Yellow 14
Titanium dioxide: Pigment White 7
Bengal (iron oxide): Pigment Red 101
Aluminum paste: Pigment Metal 1 (solid content 50%)
Carbon Black: Pigment Black 7
Pigment dispersant: Addisper PB824 (manufactured by Ajinomoto Fine-Techno Co., Inc.)
Wax: Polyethylene wax, alcohol solvent, solid content 25% (Mitsui Chemicals, Inc.)

CAP varnish 1
A round bottom flask equipped with a stirrer was charged with 42.5 parts of isopropyl alcohol, 21.25 parts of ethyl acetate, and 21.25 parts of n-propyl acetate, and with stirring, cellulose acetate propionate CAP-504-0.2. CAP varnish 1 was prepared by adding 15 parts of (number average molecular weight 15,000, propionyl content 40 to 45%, manufactured by Eastman Chemical Company). The resin solid content of the CAP varnish 1 was 15%.

CAP varnish 2
A round-bottomed flask equipped with a stirrer was charged with 42.5 parts of isopropyl alcohol, 21.25 parts of ethyl acetate, and 21.25 parts of n-propyl acetate, and with stirring, cellulose acetate propionate CAP-482-0.5. CAP varnish 2 was prepared by adding 15 parts of (number average molecular weight 25,000, propionyl content 43 to 47%, Eastman Chemical Co., Ltd.). The resin solid content of the CAP varnish 2 was 15%.

CAB varnish 1
A round bottom flask equipped with a stirrer was charged with 42.5 parts of isopropyl alcohol, 21.25 parts of ethyl acetate, and 21.25 parts of n-propyl acetate, and cellulose acetate butyrate CAB-381-0.5 (with stirring. A CAB varnish 1 was prepared by adding 15 parts of a number average molecular weight of 30,000, butyryl content of 36 to 40%, manufactured by Eastman Chemical Company. The resin solid content of CAB varnish 1 was 15%.

CAB varnish 2
A round bottom flask equipped with a stirrer was charged with 42.5 parts of isopropyl alcohol, 21.25 parts of ethyl acetate, and 21.25 parts of n-propyl acetate, and while stirring, cellulose acetate butyrate CAB-553-0.4 ( A CAB varnish 2 was prepared by adding 15 parts of a number average molecular weight of 20,000, butyryl content of 44 to 50%, manufactured by Eastman Chemical Company. The resin solid content of CAB varnish 2 was 15%.

Nitrocellulose Resin Varnish A round bottom flask equipped with a stirrer was charged with 36 parts of isopropyl alcohol, 21.3 parts of ethyl acetate, and 21.3 parts of n-propyl acetate, and nitrified cotton RS1 / 16 (manufactured by TNC) while stirring. Was added to prepare a nitrocellulose resin varnish. The resin solid content of the nitrocellulose resin varnish was 15%.

  For each ink, the ink stability, blocking resistance, thermal laminate strength, adhesion, and moldability were evaluated and are shown in Tables 38 to 45, respectively.

<Ink stability>
The ink was diluted by adding a mixed solvent of isopropyl alcohol and ethyl acetate (1/1 weight ratio), and Zahn cup No. In step 3, the viscosity was adjusted to 15 seconds. Further, 50% by weight of the initial weight of the ink was added to the above mixed solvent, and the state of the ink after 2 hours was visually observed and evaluated. Ink stability was judged to be good when the ink did not undergo phase separation and showed no change in viscosity. Regarding the state of the ink, ○: no change from immediately after adjustment (no phase separation, no viscosity change), Δ: slightly phase separation, viscosity increase (no practical problem), ×: phase separation, viscosity increase It was evaluated in four grades, that is, it cannot be practically used, and XX: cannot be made into ink. In addition, the following evaluations were not carried out for those evaluated as XX: not inkable (indicated by "-" in the table).

[Production of printed matter]
1- to 4-color printing units of 4-color gravure printing machine (manufactured by Fuji Machine Industry Co., Ltd.), ceramic doctor (manufactured by Tokyo Manufacturing Co., Ltd.), chrome hardness 1050 Hv / stylus 130 degrees engraving helio plate (Co., Ltd.) (Manufactured by Towa Process Co., Ltd.), a furnisher roll is attached, and the ink is diluted with a solvent AC372 (manufactured by Tokyo Ink Co., Ltd.) to obtain Zahn cup No. After adjusting the viscosity to 15 seconds in step 3, ink was added to the ink pan of the first unit. In all units, a styrene (OPS) film (GM, manufactured by Asahi Kasei Co., Ltd.) with a thickness of 20 μm at a doctor pressure of 2 kgf / cm ² , a drying temperature of 50 ° C., a printing pressure of 2 kg / cm ² , and a printing speed of 150 m / min. Printing was performed to obtain a printed matter of 8,000 m. Further, the viscosity was maintained constant during printing with a viscosity controller (manufactured by Meisei Co., Ltd.). Then, the blocking resistance and the heat lamination strength were evaluated.

<Blocking resistance>
The printed matter is cut into a size of 3 cm × 3 cm, the printed surface and the non-printed surface are overlapped with each other, and a load of 500 g / cm ² is applied at 50 ° C. for 24 hours. The peeling state of the ink when peeled was observed, and the peeling resistance at that time was evaluated. Those having no ink peeling and no peeling resistance were judged to have good blocking resistance. Regarding ink peeling and peeling resistance, ○: No ink peeling and no peeling resistance, Δ: Slight ink peeling and peeling resistance, ×: Ink peeling was observed over the entire area, and there was considerable peeling resistance. It was evaluated in three stages.

<Thermal lamination strength>
Ink Nos. Of Examples 1 to 270 and Comparative Examples 1 to 86. 1-270, No. The printed layer surface of the printed matter produced using 541 to 626 and the expanded polystyrene sheet (highly foamed PS sheet) are combined, a 12 μm-thick polyester film is placed on the film side of the printed matter, and a temperature of 120 ° C. is obtained using a laminator. Lamination was performed by thermocompression bonding at a speed of 5 m / min, and then the polyester film was removed to form a laminate. Adhesive tape was attached to the styrene film surface of the laminate, cut into a width of 25 mm, and heat laminated under the conditions of a peeling speed of 300 mm / min and a peeling angle of 90 ° by a tensile tester (manufactured by Orientec Co., Ltd., RTE-1210). The strength was measured. In the peel strength test, it was judged that the styrene film was broken. The peel strength test was evaluated in two stages: ◯: the styrene film was cut, x: other than that.

  In the peeling strength test, peeling is performed from a portion having the weakest adhesive strength, and in the case of peeling between the ink and the high-foamed PS sheet, the thermal lamination strength of the ink with respect to the high-foamed PS sheet is a standard. In addition, when the adhesion to the styrene film and the heat lamination strength are both strong, the peeling interface does not peel in the "layer", and the ink is pulled by both the styrene film and the high-foam PS sheet, and is torn off, resulting in cohesive failure. The phenomenon called is happening. Further, the most preferable peeling is considered to be a state in which the styrene film is cut, but not the cohesive failure, although the ink is pulled to both as in the above.

  The moldability was evaluated by the following test.

<Moldability during container molding>
In the same manner as in [Production of printed matter], printed matter in which the styrene base material is a PS sheet (Denka Styrene Sheet, manufactured by Denka Co., Ltd.) using each ink of Examples 1 to 270 and Comparative Examples 1 to 86 Was formed. Using a vacuum forming machine (small vacuum forming machine forming series 300X type, manufactured by Nariko Sangyo Co., Ltd.), a square container having a side of 100 mm was created. The appearance of the prepared container was visually observed. Those in which the printed base material layer did not have holes or cracks were judged to be good. ◯: The hole was not opened or cracked, ×: The hole was opened or cracked, and the evaluation was made in two stages.

<Adhesion>
Ink Nos. Of Examples 271 to 540 and Comparative Examples 87 to 174 were processed in the same manner as in [Preparation of printed matter]. 271-540, No. 627 to 714 were used to form a printed material in which the styrene base material was a PS shrink film (Fancy Wrap GMGS, manufactured by Gunze Co., Ltd.). An adhesive tape (18 mm, manufactured by Nichiban Co., Ltd.) was attached to the printed layer surface of the produced printed matter, and it was rapidly peeled at an angle of 90 degrees, and the peeled state of the peeled printed layer surface was evaluated. When the printed layer surface did not peel off, the adhesion was judged to be good. The adhesiveness was evaluated in two grades: ◯: no peeling at all, ×: peeling at all.

  The moldability was evaluated by the following test.

<Formability when shrinking>
The printed material formed in <Adhesion> was wrapped around a PET bottle and heated in a constant temperature drying oven at 100 ° C for 1 minute to heat-shrink the PS shrink film and bring it into close contact with the PET bottle. The printed surface of the adhered PS shrink film was observed with a microscope. Those in which the printed surface on the base material layer follows the shape of the PET bottle when the printed base material layer is heat-shrinked (the ink film follows and the cracks do not occur) were judged to be good. ◯: No cracks were generated, ×: Cracks were generated.

From the results of Table 38 to Table 40 and Table 44, the styrene-based gravure printing ink compositions of the present invention of Examples 1 to 270 have good ink stability and are suitable for molding containers such as PS sheets. The blocking resistance of the styrene substrate printed on the material layer, the heat lamination strength at low temperature, and the moldability (container moldability) were good. A styrene-based gravure ink composition for a styrene substrate using an acrylic resin obtained by synthesizing only an acrylic monomer containing a (meth) acrylic acid ester having a hydrophobic residue has anti-blocking property, thermal lamination strength at low temperature, and Moldability is poor. The gravure printing ink composition for a styrene substrate using an acrylic resin obtained by synthesizing from an acrylic monomer that does not contain a (meth) acrylic acid ester having a hydrophobic residue, which is an example of Patent Document 1, has a low temperature Laminate strength and moldability are poor.
Further, from the results of Table 41 to Table 43 and Table 45, the gravure printing ink composition for a styrene substrate of the present invention of Examples 271 to 540 has good ink stability and is suitable for shrink molding such as PS shrink film. Blocking resistance, adhesion, and moldability (shrink moldability) of the styrene base material printed on a suitable styrene base material layer were good. Gravure printing ink compositions for styrene substrates using an acrylic resin synthesized by only an acrylic monomer containing a (meth) acrylic acid ester having a hydrophobic residue have poor blocking resistance, adhesion and moldability. . A gravure printing ink composition for a styrene substrate using an acrylic resin, which is an example of Patent Document 1, is prepared by synthesizing from an acrylic monomer that does not contain a (meth) acrylic acid ester having a hydrophobic residue. Poor suitability. Further, Comparative Example 173, which is an example of Patent Document 2, is an ink composition using an acrylic resin synthesized from an acrylic monomer that does not contain a (meth) acrylic acid ester having a hydrophobic residue, and could not be made into an ink. . Comparative Example 174, which is an example of Patent Document 3, can be made into an ink, but thickening is observed, and blocking resistance, adhesion, and moldability are poor.

Claims (6)

At least one acrylic monomer selected from lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate, and an acrylic resin obtained by synthesizing methyl methacrylate and butyl methacrylate ,
3% to 50% by mass of at least one acrylic monomer selected from lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate in 100% of the acrylic resin , and methyl methacrylate. And the total amount of butyl methacrylate is 50 to 97% by mass, a gravure printing ink composition for a styrene substrate. Furthermore, containing a fiber resin,
The solid content weight (A) of the acrylic resin and the solid content weight (B) of the fiber resin are in a ratio of A / B = 100/0 to 50/50. Gravure printing ink composition for styrene base material.   Furthermore, the gravure printing ink composition for styrene base materials of Claim 1 or 2 containing a pigment.   The gravure printing ink composition for a styrene substrate according to claim 3, wherein the pigment is at least one selected from an inorganic pigment and an organic pigment.   A laminate having a printed layer formed on at least one of the styrene substrates using the styrene-based gravure printing ink composition according to any one of claims 1 to 4.   A packaging container produced by using the laminate according to claim 5.