JP7128077B2 - Aqueous printing ink composition for surface printing film - Google Patents

Description

The present invention relates to an aqueous printing ink composition for surface printing films.

BACKGROUND ART Packaging materials using various plastic films are used for food, confectionery, household goods, pet food, and the like from the viewpoints of design, economy, protection of contents, transportability, and the like. In addition, many packaging materials are subjected to gravure printing or flexographic printing with the intention of imparting designs and messages appealing to consumers.
In order to obtain these packaging materials, surface printing is performed on the surface of the base film of the packaging material, or an adhesive or anchoring agent is applied to the printed surface of the base film of the packaging material as necessary, Printing is performed by laminating the film.
In printing, after sequentially printing color ink and white ink on various films such as polyester, nylon, and aluminum foil, dry lamination using an adhesive or anchor coating agent is performed on the printed layer of the white ink. A polyethylene film, a polypropylene film, or the like is laminated for the purpose of heat sealing by extrusion lamination or the like (see, for example, Patent Document 1).

A water-based printing ink composition for surface printing film containing a hydrazine compound and a carbodiimide compound is known (see, for example, Patent Document 2). Compositions are also known, but none of them take heat resistance into consideration.

JP-A-5-97959 JP 2018-076431 A JP 2017-190416 A

An object of the present invention is to provide an aqueous printing ink composition for surface printing films as a printing ink composition for films, and to provide an aqueous printing ink composition for surface printing films with improved heat resistance.

The present inventors conducted intensive studies to solve the above problems, and as a result, invented the following water-based printing ink composition for surface printing films.
1. An aqueous printing ink composition for a surface printing film containing a pigment, a binder resin and an aqueous medium, and further comprising 0.1 to 1.0% by mass of an anionic surfactant in the ink composition. water-based printing ink composition.
2. 1. The anionic surfactant is a phosphate surfactant. A water-based printing ink composition for surface printing films as described.
3. 1. The binder resin is an acrylic emulsion having an acid value of 10 to 100 mgKOH/g and a glass transition temperature of -30 to 150°C, and the ink contains 5 to 30% by mass of solid content. or 2. 3. The water-based printing ink composition for surface printing film according to .
4. 2. The acrylic emulsion is at least one selected from an acrylic emulsion, a styrene/acrylic emulsion, an acrylic/maleic acid emulsion and a styrene/acrylic/maleic acid emulsion; 3. The water-based printing ink composition for surface printing film according to .
5. 1. Further containing an alkali-soluble resin as a binder resin. ~ 4. 3. The water-based printing ink composition for surface printing film according to any one of the above.

The water-based printing ink composition for surface printing films of the present invention can exhibit excellent adhesion to resin films, heat resistance, water resistance and abrasion resistance in a well-balanced manner.

The water-based printing ink composition for surface printing films of the present invention is described in more detail below.
<Pigment>
As pigments that can be used in the present invention, various inorganic pigments and/or organic pigments that are generally used in printing inks can be used.
Inorganic pigments include colored pigments such as titanium oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, carbon black, and graphite, silica, calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, talc, and the like. Extender pigments can be mentioned.
Examples of organic pigments include soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments.
The content of the pigment in the present invention is preferably 0.5 to 40.0% by mass in the water-based printing ink composition for surface printing film. When the content of the pigment in the water-based printing ink composition for surface printing film is less than the above range, the coloring power of the water-based printing ink composition for surface printing film is reduced. The viscosity of the water-based printing ink composition is increased, and the printed matter becomes easily soiled.

<Binder resin>
(Aqueous resin emulsion)
The aqueous resin emulsion used as the binder resin preferably has an acid value of 10 to 100 mgKOH/g, and is an acid-group-containing aqueous resin emulsion obtained by neutralizing part or all of the acid value with a volatile basic compound.
At least one emulsion selected from acrylic emulsion, styrene/acrylic emulsion, acrylic/maleic acid emulsion and styrene/acrylic/maleic acid emulsion is preferable as the acid group-containing aqueous resin emulsion.
Specifically, it is an acid group-containing aqueous resin emulsion obtained by emulsion polymerization of an ethylenically unsaturated monomer in an aqueous solvent using a water-soluble resin having a carboxyl group as a polymer emulsifier.

A specific example of the acid group-containing aqueous resin emulsion will be described.
The water-soluble resin having a carboxyl group for obtaining the acid-group-containing aqueous resin emulsion in the present invention includes component i: 2 to 50% by mass of a carboxylic acid and/or an acid anhydride having a radically polymerizable double bond, Component ii (used as necessary): 0 to 5% by mass of a ketone compound and/or aldehyde compound having a radically polymerizable double bond, and component iii: a radically polymerizable double bond excluding components i and ii It is a copolymer resin that is obtained by copolymerizing 50 to 98% by mass of a compound having and is soluble in an alkaline aqueous solution. Here, the i, ii and iii components are collectively referred to as the I component.

Here, the i component includes monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid and itaconic acid; Acid anhydrides such as maleic anhydride, citraconic anhydride and itaconic anhydride can be mentioned.
Among these carboxylic acids and/or acid anhydrides having a radically polymerizable double bond, monocarboxylic acids, particularly acrylic acid or methacrylic acid, are preferred from the standpoint of emulsifying ability of the resulting polymer emulsifier.

Next, the ketone compound having a radically polymerizable double bond of component ii is a radically polymerizable compound having at least one or more keto groups in the molecule, specifically diacetone (meth)acrylamide, Diacetone (meth)acrylate, acetonyl (meth)acrylate, vinyl alkyl ketones and the like can be mentioned.
In addition, the aldehyde compound having a radically polymerizable double bond of component ii is a radically polymerizable compound having at least one or more aldo groups in the molecule, which includes acrolein, formylstyrene, and alkanal (meth)acrylates. etc. can be mentioned.

Next, as component iii, for example, (meth)acrylic acid derivatives, styrene compounds and maleic acid derivatives described below can be used.
(Meth)acrylic acid derivatives: alkyl esters of (meth)acrylic acid having 1 to 18 carbon atoms, alkylamides having 1 to 18 carbon atoms, hydroxyalkyl esters having 2 to 4 carbon atoms, etc. Specifically, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, methyl (meth)acrylate ) acrylamide, ethyl (meth)acrylamide, butyl (meth)acrylamide, hexyl (meth)acrylamide, 2-hydroxyethyl (meth)acrylate and the like.

Styrene-based compound: Styrene and derivatives having about 8 to 10 carbon atoms, specifically α-methylstyrene, chlorostyrene, vinyltoluene, and the like.
- Maleic acid derivatives: dialkyl esters of maleic acid having 1 to 18 carbon atoms, dialkylamides having 1 to 18 carbon atoms, dihydroxyalkyl esters having 2 to 4 carbon atoms, etc. Specifically, dimethyl Maleate, diethylmalate, dibutylmalate, dioctylmalate, bis-2-hydroxyethylmalate, maleic acid dimethylamide, maleic acid diethylamide, maleic acid dibutylamide and the like can be mentioned.

In order to obtain a water-soluble resin having a carboxyl group, the amount of component i used is preferably 2 to 50% by mass, more preferably 5 to 20% by mass, and the amount of component ii used is 0 to 5% by mass. Preferably, it is 1 to 4% by mass, and the amount of component iii is preferably 50 to 98% by mass.
Here, if the amount of component i used is less than the above range, the water-soluble resin having a carboxyl group may not be sufficiently soluble in an alkaline aqueous solution, resulting in stability of emulsion polymerization, Dispersion stability may be lowered, and fluidity of the resulting water-based printing ink composition for surface printing film may be poor. On the other hand, when the above range is exceeded, water resistance and printability may deteriorate, which is not preferable.
Further, when the amount of component ii used exceeds the above range, the obtained water-based printing ink composition for surface printing film may increase in viscosity and solidify over time, and may cause deterioration in printability.

As a method for obtaining a water-soluble resin having a carboxyl group by copolymerizing the above component I, a mixture of the above compounds is reacted at a predetermined temperature and reaction time in an organic solvent in the presence of a polymerization initiator, and then A method of distilling off the organic solvent can be used.
Examples of usable organic solvents include esters such as ethyl acetate and isopropyl acetate, ketones such as acetone and methyl ethyl ketone, lower alcohols, glycols and their derivatives. As initiators, persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, organic peroxides such as benzoyl hydroperoxide, azo compounds such as azobisisobutyronitrile, and if necessary Redox initiators in combination with reducing agents can also be mentioned.

When this water-soluble resin having a carboxyl group is used as a polymer emulsifier, the preferred molecular weight (number average molecular weight, hereinafter the same) is in the range of 3,000 to 100,000, more preferably in the range of 5,000 to 30,000. is. When the molecular weight is lower than 3,000, another means is required to impart water resistance and blocking resistance to the resulting water-based printing ink composition for surface printing films, while when it is higher than 100,000, it is obtained The viscosity of the water-based printing ink composition for surface printing film is increased.
The acid value of the water-soluble resin having carboxyl groups is preferably 20-300 mgKOH/g. If the acid value is less than 20 mgKOH/g, sufficient solubility in an alkaline aqueous solution cannot be obtained, while if it exceeds 300 mgKOH/g, the water resistance and printability of the water-based printing ink composition for surface printing films are lowered. Tend.

Next, as the compound II having a radically polymerizable double bond to be subjected to emulsion polymerization, component iv (used as necessary): a ketone and/or aldehyde compound having a radically polymerizable double bond; Component v: A compound having a radically polymerizable double bond, excluding component iv. In the present invention, the iv and v components are collectively referred to as the II component.
Here, as component iv, ketones and aldehyde compounds having a radically polymerizable double bond shown as component ii above can be mentioned.

On the other hand, as the component v, the carboxylic acid and/or acid anhydride having a radically polymerizable double bond exemplified as the component i above, the (meth)acrylic acid derivative exemplified as the component iii above, a styrenic compound, and malein. Examples thereof include acid derivatives, and vinyl esters of saturated carboxylic acids having 2 to 18 carbon atoms, such as vinyl acetate, vinyl propionate, vinyl laurate and vinyl stearate.
Among these components v, (meth)acrylic acid derivatives and styrenic compounds are preferred in terms of the dispersibility of the aqueous resin emulsion and the performance of the resulting aqueous printing ink composition for surface printing films.

The amount of component iv used is preferably 0 to 30% by mass, and the amount of component v used is preferably 70 to 100% by mass in the total amount of component II.
Here, when the amount of component iv used exceeds 30% by mass, thickening and solidification over time and deterioration in printability may occur, which may not be preferable.

When a water-soluble resin having a carboxyl group is used as a polymer emulsifier and component II is used to synthesize an aqueous resin emulsion, an acid group-containing aqueous resin emulsion, or an acrylic emulsion, as a result, components ii and iv The sum of the masses is 0.5 to 25% by mass with respect to the sum of the masses of all monomer components i to v. Here, if the sum of the masses of components ii and iv is less than 0.5% by mass, the adhesion of the ink to the plastic film is lowered, which is undesirable.

The mass ratio of component I/component II is in the range of 20/80 to 80/20, preferably 30/70 to 70/30.
Here, if the mass ratio of component I is lower than 20/80, the resolubility, fluidity, and storage stability of the ink may decrease. may decline.

As a method for producing an acid-group-containing resin emulsion using the alkali-soluble resin obtained by copolymerizing the above component I, component II, and an alkaline aqueous solution, the alkali-soluble resin is dissolved in an alkaline aqueous solution, followed by A method can be used in which a mixture of the component II and the polymerization initiator is added dropwise and reacted at a predetermined temperature and reaction time.
Here, as the alkaline substance used for dissolving the alkali-soluble resin in water, a volatile basic compound, which will be described later, is used. The most appropriate amount of the alkaline substance to be used is about 100 to 120% of the neutralized amount of the alkali-soluble resin. On the other hand, even if it is more than 120%, the solubility does not become better.
Moreover, as the polymerization initiator, the polymerization initiator used for producing the alkali-soluble resin can be used.

Among the resins obtained above, the glass transition temperature is preferably -30 to 150°C, more preferably -25 to 120°C. If the glass transition temperature is less than −30° C., the heat resistance may deteriorate.
Further, acrylic emulsions, styrene-acrylic emulsions, acrylic-maleic acid emulsions and styrene-acrylic-maleic acid emulsions containing acid groups are preferred. The resin solids content in the emulsion is 20-60% by weight.
When these resins are resin emulsions, the acid value is preferably 10 to 100 mgKOH/g, more preferably 20 to 90 mgKOH/g, still more preferably 30 to 70 mgKOH/g. If the acid value is less than 10 mgKOH/g, the dispersibility of the water-based printing ink composition for surface printing film in a water-based solvent may be insufficient. On the other hand, when the acid value exceeds 100 mgKOH/g, the stability of the water-based printing ink composition for surface printing film may be impaired.
The content of the water-based resin emulsion in the water-based printing ink composition for surface printing film of the present invention is preferably 5 to 30% by mass, more preferably 10 to 25% by mass in terms of solid content.
These resin emulsions may or may not be core-shell type.

(Water-soluble acrylic resin)
The water-based printing ink composition for surface printing film of the present invention preferably contains a water-soluble acrylic resin for dispersing the pigment.
As the water-soluble acrylic resin, an alkali-soluble resin in which some or all of the acid groups are neutralized with a volatile basic compound can be used.
Monomer components constituting such an alkali-soluble resin include a monomer having a carboxyl group, a monomer containing a hydrophobic group for improving adsorption to pigments, and other polymerizable monomers. consists of quanta.
Examples of monomers having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, 2-carboxyethyl (meth)acrylate, 2-carboxypropyl (meth)acrylate, maleic anhydride, Maleic acid monoalkyl ester, citraconic acid, citraconic anhydride, citraconic acid monoalkyl ester and the like can be used.
As the monomer containing a hydrophobic group for improving the adsorptivity with the pigment, preferably a (meth)acrylate having a long-chain alkyl group having 6 to 20 carbon atoms, especially 2-ethylhexyl (meth) ) acrylate, octyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, 2-hydroxystearyl (meth) acrylate, etc. are more preferable, and styrene monomers such as styrene, α-styrene, vinyl Toluene or the like can be used.
Other polymerizable monomers are monomers that can be used within a range that does not impair the properties of the alkali-soluble resin, such as methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. , (meth) acrylic acid such as isopropyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, hydroxyethyl (meth) acrylate, acrylamide, N-methylolacrylamide, cyclohexyl (meth) acrylate, Benzyl (meth)acrylate and the like can be used.
The acid value of the alkali-soluble resin is preferably 40-250 mgKOH/g, more preferably 70-250 mgKOH/g. If the acid value is less than 40 mgKOH/g, the solubility of the water-based printing ink composition for surface printing film in the water-based solvent may be insufficient. On the other hand, when the acid value exceeds 250 mgKOH/g, the hydrophilicity becomes too high, which may deteriorate the storage stability and water resistance.
As for the molecular weight of the alkali-soluble resin, the weight average molecular weight is preferably 3,000 to 200,000, more preferably 5,000 to 50,000. When the weight-average molecular weight of the alkali-soluble resin is less than 3,000, the dispersion stability of the pigment and the scratch resistance of the resulting printed matter tend to decrease. do not have.
The amount of the alkali-soluble resin to be blended is preferably 10 to 100 parts by mass with respect to 100 parts by mass of the pigment described above.
It is also possible to use a pigment dispersant instead of using a water-soluble acrylic resin.

(volatile basic compound)
Examples of the volatile basic compound in the present invention include ammonia, triethylamine, N,N-dimethylethanolamine, monoethanolamine, etc. Among them, ammonia is preferred. Inorganic alkali compounds such as sodium hydroxide and potassium hydroxide, and non-volatile amine compounds such as triethylenediamine, diethanolamine, triethanolamine, diethylenetriamine, and diazabicyclooctane can also be used in combination, as long as the performance does not deteriorate.

The acid value is a theoretical acid value obtained by arithmetically determining the number of mg of potassium hydroxide theoretically required to neutralize 1 g of resin based on the composition of the monomers used for synthesizing the resin. .
A weight average molecular weight can be measured by a gel permeation chromatography (GPC) method. As an example, chromatography is performed using Water 2690 (manufactured by Waters) as a GPC device and PLgel 5 μm MIXED-D (manufactured by Agilent Technologies) as a column, and the weight average molecular weight can be obtained in terms of polystyrene.

<Anionic surfactant>
The water-based printing ink composition for surface printing film of the present invention contains an anionic surfactant for improving heat resistance.
Phosphate-based surfactants, alkenylsuccinic acid-based surfactants, taurine-based surfactants, and the like can be used as anionic surfactants.
Phosphate-based surfactants are preferably phosphate-based surfactants, and Plysurf AL, Plysurf DB-01, Plysurf A219B, Plysurf A208B, and Plysurf 212C (Daiichi Kogyo Seiyaku Co., Ltd.) are used. be able to. An alkenyl succinic acid surfactant and/or a taurine surfactant can be used together with the phosphate surfactant.
As alkenyl succinic acid or a salt thereof, alkenyl succinic acid (Seiko PMC) and dipotassium alkenyl succinate (Kao) can be used.
In addition, N-acyl taurine salt (Nikko Chemicals), LMT (N-lauroylmethyltaurate Na), MMT (N-myristoylmethyltaurate Na), SMT (N-stearoylmethyltaurate Na), PMT (N-palmitoylmethyltaurate) Na), N-acylsarcosine, N-oleoylsarcosine (Nikko Chemicals), N-acylglycine can also be used.
The content of the anionic surfactant in the water-based printing ink composition for surface printing film of the present invention is preferably 0.1 to 1.0% by mass, more preferably 0.3 to 0.5% by mass. is.
By blending such an anionic surfactant, the heat resistance can be improved, so that the heat sealing resistance can be strengthened. If the amount is less than 0.1% by mass, a sufficient addition effect may not be obtained, and if the amount is more than 1.0% by mass, water resistance and trapping properties may decrease. .
Cationic surfactants, nonionic surfactants, and amphoteric surfactants can also be blended as long as the effects of the anionic surfactant in the present invention are not impaired.

<Water-soluble organic solvent used as aqueous medium>
Examples of water-soluble organic solvents used with water as aqueous media include monoalcohols, polyhydric alcohols, lower alkyl ethers of polyhydric alcohols, ketones, ethers, esters, nitrogen-containing compounds, and the like. can be mentioned. These may be used alone or in combination of two or more.
Examples of the monoalcohols include methanol, ethanol, n-propanol, n-butanol, isobutanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonyl alcohol, n-decanol, or these. isomers, cyclopentanol, cyclohexanol, etc., and preferably alcohols having an alkyl group of 1 to 6 carbon atoms can be used.
Examples of the polyhydric alcohols include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,2-pentanediol, 1,5-pentanediol, neopentyl glycol, 1,2- Hexanediol, 1,6-hexanediol, 1,2-cyclohexanediol, heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, glycerin, pentaerythritol, diethylene glycol, dipropylene Glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol and the like can be used.
Examples of lower alkyl ethers of polyhydric alcohols include ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monopropyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether, and ethylene glycol. Isobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol-n-propyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono -n-butyl ether and the like can be used.
The content of the water-soluble organic solvent in the water-based printing ink composition for surface printing film is preferably as low as possible, and may be omitted.
However, the content at the time of blending is preferably 0 to 10.0% by mass, more preferably 0 to 5.0% by mass in the water-based printing ink composition for surface printing film. If it exceeds 10.0% by mass, poor drying and anti-blocking properties will decrease.

<Other additives>
In addition, various additives such as an anti-blocking agent, an antifoaming agent, and an antistatic agent can be added depending on the necessity of ink performance and within a range that does not impair the effects of the present invention. In addition, a hydrazine compound or a carbodiimide compound may be incorporated in order to improve physical properties of the coating film such as water resistance and abrasion resistance.

[Production of water-based printing ink composition for surface printing film]
A method for producing a water-based printing ink composition for surface printing films using the various materials described above includes mixing a pigment, a binder resin, an anionic surfactant, an aqueous solvent, and, if necessary, a pigment dispersant. In general, the mixture is kneaded with a squeegee, and then the rest of the predetermined materials such as the cross-linking agent are added and mixed.

[Print]
The water-based printing ink composition for surface printing films obtained by the above method can be printed on a plastic film by a flexographic printing method or a gravure printing method.
Plastic films on which the water-based printing ink composition for surface printing films of the present invention is printed include various plastic films such as polyolefin, polyester, and nylon, and in particular, those subjected to surface treatment such as corona discharge treatment are more preferable. be.

[Method for producing water-based printing ink composition for surface printing film of the present invention]
The water-based printing ink composition for surface printing film of the present invention is produced by using various dispersing/kneading devices generally used in the past by using various materials such as the above-mentioned pigment, water-soluble acrylic resin, and aqueous medium, and then It can be obtained by adding an aqueous resin emulsion, an anionic surfactant and an aqueous medium and stirring and mixing.

[Print]
A flexographic printed matter can be obtained by printing on a substrate film by a flexographic printing method using the water-based printing ink composition for a surface printing film.

[Base film]
The base film to be printed with the water-based printing ink composition for surface printing film of the present invention is not particularly limited. Polyolefin films such as polyethylene and polypropylene, polyester films such as polyethylene terephthalate, polylactic acid and polycaprolactone, Various printing resin films such as nylon and vinylon can be used.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass".

Water-soluble acrylic resin: styrene/lauryl methacrylate/acrylic acid copolymer,
AV100mgKOH/g, Tg107°C, Mw11000,
Ammonia neutralization, solid content 28% by mass
Emulsion resin A: styrene acrylic resin emulsion
AV62mgKOH/g, Tg7°C
Emulsion resin B: acrylic resin emulsion
AV42mgKOH/g, Tg-24°C
Emulsion resin C: styrene acrylic resin emulsion
AV87mgKOH/g, Tg117°C
<Manufacture of printed matter>
Aqueous printing ink composition for surface printing film (Examples Y1 to Y10, Comparative Examples Y1 to Y3, Examples B1 to B4, Comparative Examples B1 to B3), using a flexographic printing machine on the treated surface of the film, under the following conditions A print was obtained by printing and drying. Adhesion to a substrate, heat resistance, and water resistance and abrasion resistance were evaluated using the resulting printed matter. A specific evaluation method is shown below.
(Printing method/Printing conditions)
Film: OPP (corona-discharged biaxially oriented polypropylene film, manufactured by Toyobo
P-2161, thickness 25 μm)
Room environment during printing: temperature 25°C, humidity 50%
Coating machine: Flexographic printing machine
Coating speed: 150m/min
Printing plate: Solid plate Drying temperature: 55°C

(Substrate adhesion)
Adhesion was evaluated from the degree of peeling of the printed film from the film when a cellophane tape was attached to the printed surface and quickly peeled off.
A: The printed film does not peel off from the film at all B: Less than 20% of the printed film peeled off from the film C: 20% or more and less than 50% of the printed film peeled off from the film D: As the area ratio of the printed film, 50% or more was peeled off from the film

(Heat-resistant)
Using a heat seal tester equipped with a hot plate having a thermal gradient of 80 to 250° C., the printed surface and aluminum foil were pressed against each other at 2.0 kg/cm ² . with pressure,
Press for 1 second.
The heat resistance was evaluated from the minimum temperature at which the ink on the printed surface transferred to the aluminum foil.
A: 200°C or higher B: 160°C or higher and lower than 200°C C: 140°C or higher and lower than 160°C D: Lower than 140°C

(Water and abrasion resistance)
Kanakin immersed in water was used as a friction element on the printed surface, and a load of 200 g was reciprocated 100 times using a Gakushin testing machine (Daiei Kagaku Seiki Seisakusho), and water resistance and abrasion resistance were evaluated from the degree of ink drop.
A: No ink dropout B: Ink dropout in the range of less than 20% C: Ink dropout in the range of 20% or more and less than 50% D: Ink dropout in the range of 50% or more

According to the above results, it was possible to obtain a water-based printing ink composition for a surface printing film, which is excellent in substrate adhesion, heat resistance, and water resistance and abrasion resistance, according to the examples, which are examples according to the present invention. . On the other hand, according to Comparative Examples Y1, B1 and B3, in which the amount of the anionic surfactant is small, the heat resistance deteriorates, and in contrast, according to Comparative Examples Y2 and B2, in which the amount of the anionic surfactant is large, the water resistance The result was inferior to friction resistance.

Claims (4)

A water-based printing ink composition for a surface printing film containing a pigment, a binder resin, and an aqueous medium, and further comprising a phosphate ester-based surfactant and/or a taurine-based surfactant as an anionic surfactant. Aqueous printing ink composition for surface printing film containing 0.1 to 1.0% by mass in the composition. The surface printing according to claim 1 , wherein the binder resin is an acrylic emulsion having an acid value of 10 to 100 mgKOH/g and a glass transition temperature of -30 to 150°C, and the solid content of this in the ink is 5 to 30% by mass. A water-based printing ink composition for films. 3. The water-based printing ink composition for surface printing films according to claim 2 , wherein the acrylic emulsion is at least one selected from an acrylic emulsion, a styrene-acrylic emulsion, an acrylic-maleic acid emulsion and a styrene-acrylic-maleic acid emulsion. 4. The water-based printing ink composition for surface printing films according to any one of claims 1 to 3 , further comprising an alkali-soluble resin as a binder resin.