JP7372177B2 - Gravure printing ink composition for film, printing method, printed matter and laminate laminate - Google Patents

Description

The present invention mainly relates to a printing ink composition for printing on films for packaging materials, a printing method, printed matter obtained thereby, and a laminate.

BACKGROUND ART Packaging materials using various plastic films are used for foods, confectionery, household goods, pet foods, etc. from the viewpoints of design, economy, protection of contents, transportability, etc. Furthermore, many packaging materials are subjected to gravure printing or flexographic printing with the intention of adding designs, messages, etc. that appeal to consumers.
In order to obtain the desired packaging material, front printing is performed on the surface of the base film of the packaging material, or adhesives or anchoring agents are applied as necessary to the printing surface on the back of the base film of the packaging material. , reverse printing is performed to laminate the film.
In reverse printing, after sequentially printing colored ink and white ink on various films such as various general-purpose films (polyester, nylon), aluminum foil, and various high-performance films (films coated with inorganic or organic barrier materials), A polyethylene film, a polypropylene film, or the like is laminated on the white ink printing layer for the purpose of heat sealing by dry lamination using an adhesive, extrusion lamination using an anchor coating agent, or the like.

In particular, when a biaxially oriented polyethylene film (OPP) is laminated onto a film printed with white ink, it is sometimes difficult to obtain sufficient lamination strength.
For this reason, although it is possible to contain a chlorinated polyolefin in the ink composition, there are cases where the laminate strength is not sufficiently high even if the content is increased.
Furthermore, as in Patent Document 1, laminate strength has been improved by incorporating a metal alkoxide and a hydroxy acid into a urethane resin. In this case, it is said that the metal alkoxide has excellent stability over time, but since the properties of the metal alkoxide itself are poor in storage stability, it is preferable not to add them.

JP2017-061683A

An object of the present invention is to provide a gravure printing ink composition for films that has excellent lamination strength of a laminated film used as a printing surface.

As a result of intensive studies to solve the above problems, the present inventors have completed the following invention.
That is, the present invention is as follows.
1. A gravure printing ink composition for film containing a pigment, a polyurethane resin, and an organic solvent,
A gravure printing ink composition for films containing 0.2 to 7.0% by mass of an acid group-containing compound having a number average molecular weight of 500 or more in the solid content of the gravure printing ink composition for films.
2. 2. The gravure printing ink composition for film according to 1, wherein the acid group-containing compound has a polyether structure and/or a polyester structure.
3. 2. The gravure printing ink composition for film according to 2, wherein the acid group-containing compound has a polyoxyethylene structure.
4. 4. The gravure printing ink composition for films according to any one of 1 to 3, wherein the acid group of the acid group-containing compound is one or more selected from carboxylic acid, phosphoric acid, and sulfonic acid.

According to the present invention, even if a film such as OPP is laminated on a surface printed with a white ink composition, sufficiently high lamination strength can be achieved.

The present invention is a gravure printing ink composition for films containing a pigment, a polyurethane resin, and an organic solvent,
This gravure printing ink composition for films contains 0.2 to 7.0% by mass of an acid group-containing compound having a number average molecular weight of 500 or more in the solid content of the gravure printing ink composition for films. Hereinafter, the gravure printing ink composition for films of the present invention will be specifically explained.

(pigment)
As the pigment contained in the ink composition of the present invention, one or more of the inorganic and organic pigments that can be contained in the ink composition for back printing lamination can be used.
Examples of inorganic pigments include colored pigments such as titanium oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, navy blue, ultramarine blue, carbon black, and graphite; examples of extender pigments include silica particles, calcium carbonate, kaolin, clay, and sulfuric acid. Examples include barium, aluminum hydroxide, and talc. Among these, it is preferable to use titanium oxide as the white pigment.
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 these pigments in the ink composition is usually about 1 to 50% by mass.

(binder resin)
The binder resin includes a polyurethane resin, preferably a polyurethane resin having an amine value from the viewpoint of ink stability, adhesiveness, and lamination suitability.

<Polyurethane resin>
The polyurethane resin in the present invention includes a polyurethane resin that has not been acid-modified. This non-acid-modified polyurethane resin is a polyurethane resin that does not have acidic groups such as carboxylic acid groups, sulfonic acid groups, and phosphoric acid groups at the molecular ends and/or other locations within the molecule. As such a polyurethane resin, a polyurethane resin commonly used in printing inks can be used.
Among these, polyurethane resins having an amino group (having an amine value) are preferred from the viewpoint of ink stability over time, adhesiveness, and suitability for lamination. Among polyurethane resins having amino groups, polyurethane resins having one or more types selected from primary amino groups, secondary amino groups, and tertiary amino groups at the end of the molecule are more preferable.
More preferably, it is a polyurethane resin having a hydroxyl group and at least one type selected from a primary amino group, a secondary amino group, and a tertiary amino group at the end of the molecule.

The above acid-unmodified polyurethane resin has a specific functional group such as the above amino group, so that the gravure printing ink composition for films of the present invention has excellent printability and adhesion to films. It turns out.
In particular, when it is a gravure printing ink composition for a film for back printing, the polyurethane resin has one or more types selected from primary amino groups, secondary amino groups, and tertiary amino groups at the end of the molecule, especially at the end of the molecule. It is desirable to have at least one type selected from a primary amino group and a secondary amino group at the terminal, and it is further preferred to have a hydroxyl group.
Further, the amine value of the polyurethane resin is preferably 1.0 to 15.0 mgKOH/g, more preferably 2.0 to 8.0 mgKOH/g. If the amine value is less than 1.0 mgKOH/g, the adhesion of the printing ink composition for films of the present invention to the film may decrease, and furthermore, the suitability for lamination may decrease, and the amine value is less than 1.0 mgKOH/g. If it exceeds 0 mgKOH/g, blocking resistance may decrease.
In the present invention, the above-mentioned amine value means the amine value per 1 g of solid content, and is determined by potentiometric titration method (for example, COMTITE (AUTO TITRATOR COM-900, BURET B-900, TITSTATION) using a 0.1N hydrochloric acid aqueous solution. K-900) (manufactured by Hiranuma Sangyo Co., Ltd.) and converted into the equivalent amount of potassium hydroxide.

Such non-acid-modified polyurethane resins can be obtained by synthesizing a urethane prepolymer by reacting an organic diisocyanate compound and a polymeric diol compound, and reacting this with a chain extender and a reaction terminator as necessary. Polyurethane resins can be suitably used.
The non-acid-modified polyurethane resin used in the present invention is used as a binder.
Further, as the polyurethane resin that has not been acid-modified, a polyurethane polyurea resin and/or a ketiminated polyurethane polyurea resin is preferable.
A polyurethane polyurea resin is obtained by chain-extending and/or terminal-terminating a urethane prepolymer obtained from a diisocyanate component and a diol component.
By using a specific ketimine compound as a chain extender and/or reaction terminator and reacting it with a urethane prepolymer in a specific solvent, the resulting polyurethane polyurea resin itself does not generate the odor of ketimine, and furthermore, It has excellent stability over time when stored in a solution state such as ink or paint.

(Polyurethane polyurea resin)
The polyurethane polyurea resin has one or more types selected from primary amino groups and secondary amino groups at the end of the molecule.
More preferably, it is a polyurethane polyurea resin having a hydroxyl group and at least one type selected from a primary amino group and a secondary amino group at the end of the molecule.
These polyurethane polyurea resins are polyurethane resins obtained by synthesizing a urethane prepolymer by reacting a diisocyanate compound with a polymeric diol compound, which is a diol compound, and reacting this with the following chain extender and reaction terminator. can be suitably used.

<Synthesis of urethane prepolymer>
Each of the above urethane prepolymers is obtained by reacting the following diisocyanate compound with a polymeric diol compound.
(Diisocyanate compound)
Examples of the diisocyanate compounds include aromatic diisocyanate compounds such as tolylene diisocyanate, alicyclic diisocyanate compounds such as 1,4-cyclohexane diisocyanate and isophorone diisocyanate, aliphatic diisocyanate compounds such as hexamethylene diisocyanate, and α, α , α', α'-tetramethylxylylene diisocyanate and other aromatic aliphatic diisocyanate compounds. These diisocyanate compounds can be used alone or in combination of two or more. Among these, alicyclic diisocyanate compounds, aliphatic diisocyanate compounds, and araliphatic diisocyanate compounds are more preferred.

Further, all of the diisocyanate compounds used may be isophorone diisocyanate, but other diisocyanate compounds can be used in combination.
Other diisocyanate compounds include 1,3- and/or 1,4-phenylene diisocyanate, 4,4-diisocyanatobiphenyl, 3,3-dimethyl-4,4-diisocyanatobiphenyl, tolylene diisocyanate, etc. Aromatic diisocyanate compounds, alicyclic diisocyanate compounds such as 1,4-cyclohexane diisocyanate, cyclohexylene diisocyanate, dicyclohexylmethane-4,4-diisocyanate (hydrogenated MDI), methylcyclohexylene diisocyanate (hydrogenated TDI), ethylene diisocyanate, Aliphatic diisocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and m- and/or p-xylylene diisocyanate (XDI), α, α, Examples include aromatic aliphatic diisocyanate compounds such as α',α'-tetramethylxylylene diisocyanate, and these organic diisocyanate compounds can be used alone or in combination of two or more. Among these, alicyclic diisocyanate compounds, aliphatic diisocyanate compounds, and araliphatic diisocyanate compounds are more preferred.
When other diisocyanate compounds are used together, they can be used together so that the number of isocyanate groups in the other diisocyanate compounds is 50% or less, more preferably 30% or less, relative to the total number of isocyanate groups in all diisocyanate compounds. , more preferably 10% or less.
Or, in 100 parts by mass of all diisocyanate compounds, the amount of other diisocyanate compounds is 50 parts by mass or less, more preferably 30 parts by mass or less, still more preferably 10 parts by mass or less.

(Polymer diol compound)
Examples of the polymer diol compounds include polyalkylene glycols such as polyethylene glycol and polypropylene glycol, polyether diol compounds such as alkylene oxide adducts of bisphenol A such as ethylene oxide and propylene oxide, adipic acid, sebacic acid, and anhydride. One or more dibasic acids such as phthalic acid, and one type of glycol such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, etc. Alternatively, polyester diol compounds such as polyester diols and polycaprolactone diols obtained by condensation reaction of two or more types can be mentioned. These polymeric diol compounds can be used alone or in combination of two or more.
Furthermore, in addition to the above polymer diol compounds, alkanediols such as 1,4-pentanediol, 2,5-hexanediol, 3-methyl-1,5-pentanediol, ethylene glycol, propylene glycol, 1,4- Low molecular weight diol compounds such as butanediol and 1,3-butanediol may be used alone or in combination of two or more.

Further, as the above-mentioned polymeric diol compound, one containing 3-methyl-1,5-pentylene adipate diol can be selected. Among these, those with a number average molecular weight of 1,000 to 8,000 are preferred, those of 1,000 to 5,500 are more preferred, and those of 1,000 to 4,000 are even more preferred.
At this time, the following can be used in combination as other polymeric diol compounds.
Polymer diol compounds other than 3-methyl-1,5-pentylene adipate diol include one or more dibasic acids such as adipic acid, sebacic acid, and phthalic anhydride, and ethylene glycol, propylene glycol, Polyester diols, polycaprolactone diols, etc. obtained by condensation reaction with one or more glycols such as 1,4-butanediol, neopentyl glycol, and 3-methyl-1,5-pentanediol. Examples include polyester diol compounds, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, and polyether diol compounds such as alkylene oxide adducts of bisphenol A such as ethylene oxide and propylene oxide. These polymeric diol compounds can be used alone or in combination of two or more.

Among these, 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 1000 to 8000, which is obtained by a condensation reaction of adipic acid and 3-methyl-1,5-pentanediol, is preferable, and more preferably 3-methyl-1,5-pentylene adipate diol having a molecular weight of 1,000 to 4,000 is preferred.
When other polymeric diol compounds are used together, they can be used together so that the number of hydroxyl groups in the other polymeric diol compounds is 70% or less of the total number of hydroxyl groups in all polymeric diol compounds, but more preferably It is 55% or less, more preferably 40% or less.
Or, in 100 parts by mass of all polymer diol compounds, the amount of other polymer diol compounds is 50 parts by mass or less, more preferably 35 parts by mass or less, still more preferably 20 parts by mass or less.

Further, the polyurethane resin may contain a biomass polyurethane resin in consideration of the environment. The biomass polyurethane resin will be explained below. In addition, among the explanations of the biomass polyurethane resin, explanations common to the above-mentioned polyurethane resins will be omitted as appropriate.
Biomass polyurethane resin is a polyurethane resin containing biomass-derived (plant-derived) components. Biomass polyurethane resin can contribute to preventing global warming and reducing environmental impact compared to using other exhaustible resources, so we synthesized urethane prepolymer by reacting biopolyester polyol compound and isocyanate compound. A biomass polyurethane resin obtained by reacting this with a chain extender and a reaction terminator as necessary is preferable, and it is more preferable that the isocyanate compound is a plant-derived bioisocyanate.

(Bio polyester polyol compound)
In consideration of the environment, among the biopolyester polyol compounds, biopolyester polyol compounds synthesized from materials containing plant-derived components may be used in combination with the other polymeric diol compounds mentioned above.
Further, a polyurethane polyurea resin obtained by reacting a polyester polyol compound containing a biopolyester polyol compound with the above-mentioned specific isocyanate compound can also be used by mixing it with the polyurethane polyurea resin in the present invention.
Therefore, as the other polymeric diol compound mentioned above, a biopolyester polyol (biomass polyester polyol) obtained by reacting a short chain diol compound having 2 to 4 carbon atoms with a carboxylic acid compound can be employed. In the biopolyol component, at least one of the short chain diol compound and the carboxylic acid compound is preferably derived from a plant, and even more preferably both are derived from a plant.
The plant-derived short chain diol compound having 2 to 4 carbon atoms is not particularly limited. For example, the short chain diol compound may be 1,3-propanediol, 1,4-butanediol, ethylene glycol, etc. obtained from plant materials by the following method. These may be used in combination.
1,3-propanediol can be produced from glycerol via 3-hydroxypropyl aldehyde (HPA) by a fermentation method in which glucose is obtained by decomposing plant resources (eg, corn, etc.). The 1,3-propanediol component produced by biomethods such as the fermentation method described above is superior in terms of safety compared to the 1,3-propanediol component produced by the EO production method, and has useful properties such as lactic acid. By-products can be obtained, and production costs can also be kept low. 1,4-butanediol can be produced by producing succinic acid by producing glycol from plant resources and fermenting it, and then hydrogenating this. Furthermore, ethylene glycol can be produced from bioethanol obtained by conventional methods via ethylene.

The plant-derived carboxylic acid compound is not particularly limited. For example, carboxylic acid compounds include sebacic acid, succinic acid, lactic acid, glutaric acid, dimer acid, and the like. These may be used in combination. Among these, the carboxylic acid compound preferably contains at least one selected from the group consisting of sebacic acid, succinic acid, and dimer acid. Further, 0.05 to 0.5 parts by mass of malic acid may be contained per 100 parts by mass of sebacic acid.
The biopolyester polyol compound is produced as a 100% plant-derived biopolyester polyol by appropriately condensing a plant-derived short chain diol compound and a plant-derived carboxylic acid. Specifically, polytrimethylene sebacate polyol is obtained by direct dehydration condensation of plant-derived sebacic acid and plant-derived 1,3-propanediol. Furthermore, polybutylene succinate polyol can be obtained by direct dehydration condensation of plant-derived succinic acid and plant-derived 1,4-butanediol.
One or more of these biopolyester polyol compounds may be used.

The urethane prepolymer obtained from these plant-derived components may be contained in an amount of 10% by mass or more, or 40% by mass or more in terms of solid content in the entire urethane prepolymer.
As a method for producing the above-mentioned biomass polyurethane resin, a known method for producing a polyurethane resin using the above-mentioned materials can be used as is. Furthermore, if the molecular weight, chemical structure, or equivalent ratio of each component differs, the hardness of the resulting polyurethane resin will also differ, so by appropriately combining these components, it is possible to adjust the printability and lamination suitability. .
The weight average molecular weight of the polyurethane resin is preferably 10,000 to 70,000, more preferably 20,000 to 60,000.
Furthermore, in order to increase appropriate flexibility and laminate strength, a polyurethane resin without urea bonds may be blended as the polyurethane resin.

(Other diol compounds)
In addition to 3-methyl-1,5-pentylene adipate diol, alkanediols such as 1,4-pentanediol, 2,5-hexanediol, and 3-methyl-1,5-pentanediol, ethylene glycol, and propylene Low-molecular-weight diol compounds such as glycol, 1,4-butanediol, and 1,3-butanediol can be used alone or in combination of two or more.
In addition, when synthesizing polyurethane resin, when using a mixed solvent system of an ester solvent and an alcohol solvent (hereinafter referred to as "mixed liquid" in some cases) as the organic solvent described later, polyurethane resin is used as the polymer diol compound. When an ether diol compound, preferably polypropylene glycol, is used, the solubility of the resulting polyurethane resin tends to be high, and printability such as gradation reproducibility and fog prevention properties tends to be good. This is preferable because it allows for a wide range of ink designs to be tailored to the performance.

In addition, when reacting the diisocyanate compound and the polymeric diol compound, the ratio of each used is such that the equivalent ratio of isocyanate group to hydroxyl group (isocyanate index) is usually 1.2:1 to 3.0:1. The preferred range is 1.3:1 to 2.0:1. If the above-mentioned isocyanate index is smaller than 1.2, the polyurethane polyurea resin tends to be flexible, and the blocking resistance etc. may be low when printing the ink composition. Concomitant use may be necessary.

(Reaction between diisocyanate compound and polymer diol compound)
A catalyst can be used during the reaction between the diisocyanate compound and the polymeric diol compound to obtain the polyurethane polyurea resin used in the present invention.
Among them, it is preferable to use organometallic compounds, and examples of such organometallic compounds include titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanate, and butoxytitanium trichloride, dibutyltin sulfide, tributyltin sulfide, and tributyltin oxide. , dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, tributyltin acetate, tributyltin chloride, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide , tributyltin trichloroacetate, and tin compounds such as tin 2-ethylhexanoate; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate; and iron 2-ethylhexanoate. , iron acetylacetonate, cobalt benzoate, cobalt 2-ethylhexanoate, zinc naphthenate, zinc 2-ethylhexanoate, zirconium naphthenate, and the like. Among these, titanium compounds such as tetrabutyl titanate are preferred.
Tertiary amine compounds can also be used, such as triethylamine, triethylenediamine, 1,4-diazabicyclo(2,2,2)octane, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU). can be used.

(Chain extension and/or terminal treatment reaction)
As the chain extender, known chain extenders used in polyurethane polyurea resins as binders for inks can be used. For example, among polyamine compounds, ethylene diamine, propylene diamine, tetramethylene diamine, hexamethylene diamine, etc. can be used. aliphatic diamines, isophorone diamine, alicyclic diamines such as 4,4'-dicyclohexylmethane diamine, aromatic diamines such as toluylene diamine, aromatic aliphatic diamines such as xylene diamine, N-(2- Diamines having hydroxyl groups such as hydroxyethyl)ethylenediamine (aminoethylethanolamine), N-(2-hydroxyethyl)propylenediamine, N,N'-di(2-hydroxyethyl)ethylenediamine, ethylene glycol, propylene glycol, 1 , 4-butanediol, neopentyl glycol, diethylene glycol, triethylene glycol and the like.
Furthermore, a polyamine compound such as diethylenetriamine or triethylenetetramine can be used in combination within a range where the polyurethane polyurea resin does not gel.

As a reaction terminator for introducing a primary amino group and a secondary amino group into the terminals of a polyurethane polyurea resin, examples of polyamine compounds include aliphatic diamines such as ethylenediamine, propylene diamine, tetramethylene diamine, and hexamethylene diamine, and isophorone. diamine, alicyclic diamines such as 4,4'-dicyclohexylmethanediamine, polyamines such as diethylenetriamine and triethylenetetratriamine, aromatic diamines such as tolylene diamine, aromatic aliphatic diamines such as xylene diamine, N Examples include diamines having a hydroxyl group such as -(2-hydroxyethyl)ethylenediamine (aminoethylethanolamine) and N-(2-hydroxyethyl)propylenediamine. Among these, polyamines having a primary amino group such as diethylenetriamine and triethylenetetratriamine are preferred.
Reaction terminators that introduce hydroxyl groups into polyurethane polyurea resins include alkanolamines such as monoethanolamine and diethanolamine, and those having hydroxyl groups such as N-(2-hydroxyethyl)ethylenediamine and N-(2-hydroxyethyl)propylenediamine. Examples include diamines. In addition, known reaction terminators such as monoamine compounds and monoalcohol compounds can be used. Specifically, monoalkylamines such as n-propylamine and n-butylamine, and dialkylamines such as di-n-butylamine can be used. and monoalcohols such as ethanol.

(Ketiminated polyurethane polyurea resin)
The ketiminated polyurethane polyurea resin uses a ketimine compound obtained by ketiminating a polyamine compound in advance with an excess amount of a ketone compound among the chain extenders and/or reaction terminators mentioned above. A polyurethane polyurea resin is produced using a reaction terminator. In particular, from among the chain extenders and reaction terminators mentioned above, it is preferable to employ one or more selected from isophorone diamine, N-(2-hydroxyethyl)ethylene diamine, and ethylene diamine.
A polyamine compound ketiminated with a ketone compound has a structure in which the oxygen atom of the ketone compound is replaced by the nitrogen atom of the amino group of the polyamine compound.
Moreover, as the ketone compound to be used, acetone, diethyl ketone, methyl ethyl ketone, diacetone alcohol, and methyl isobutyl ketone are preferable.
In this ketimination reaction, it is preferable not to use any solvent other than the ketone compound.
However, as a solvent other than the ketone compound, an alcohol compound can be used, and among them, isopropyl alcohol can be used.
This not using any solvent other than the ketone compound is defined as ketimination under solvent-free conditions. Note that a polar organic solvent may be blended instead of under solvent-free conditions as long as it does not inhibit the subsequent chain elongation reaction or the fact that the polyurethane polyurea resin has no odor.
The present invention is an ink composition containing a ketiminated polyurethane polyurea resin obtained through a process of chain extension and reaction termination using a chain extender and/or a reaction terminator, and the ink composition. and printed materials do not generate ketimine odor. It also has the effect of increasing the peel strength when laminated onto a printed surface by means such as extrusion lamination.
Note that the ketiminated amine or the like may be used as a chain extender, a reaction terminator, or both a chain extender and a reaction terminator.

<Synthesis of polyurethane polyurea resin from urethane prepolymer>
The polyurethane polyurea resin of the present invention is obtained by subjecting the urethane prepolymer obtained by the above method to chain elongation and/or reaction termination with a ketimine compound.
That is, a solvent is added to the reaction product of the above-mentioned diisocyanate compound and the polymeric diol compound, if necessary, and the above-mentioned ketiminated chain extender and/or reaction terminator is added to carry out the reaction.
When using a solvent, an ester solvent and/or an alcohol solvent are preferred, a mixture of an ester solvent and an alcohol solvent is more preferred, and propyl acetate and isopropyl alcohol are even more preferred, with the mass ratio of propyl acetate:isopropyl alcohol= A range of 1 to 5:1 is most preferred.

Further, when the obtained polyurethane polyurea resin has an amino group, it is preferable that the amine value is 1 to 10 mgKOH/g. If the above amine value is less than 1 mgKOH/g, the adhesion to the printing substrate when the ink composition is printed may decrease, and even when it is made into a gravure ink composition for lamination, the adhesion to the film may be reduced. Sexuality decreases. Furthermore, lamination suitability may be reduced. When the amine value exceeds 10 mgKOH/g, blocking resistance may decrease.
This amino group may also be ketiminated.
In the present invention, the above amine value means the amine value per 1 g of solid content, and is determined by potentiometric titration method (for example, COMTITE AUTO TITRA) using a 0.1N aqueous hydrochloric acid solution.
TOR COM-900, BURET B-900, TITSTATION K-900) (manufactured by Hiranuma Sangyo Co., Ltd.), and then converted to the equivalent amount of potassium hydroxide.

[Acid-modified polyurethane resin]
Acid-modified polyurethane resins can also be used as the polyurethane resins in the present invention. It may be used together with the above-mentioned non-acid-modified polyurethane resin, or only the acid-modified polyurethane resin or only the non-acid-modified polyurethane resin.
Acid-modified polyurethane resin is produced by reacting dicarboxylic anhydride with the terminal hydroxyl group or amino group of a urethane prepolymer or polyurethane polyurea obtained by a method similar to the above-mentioned manufacturing method. By introducing a carboxylic acid group, an acid-modified polyurethane resin is obtained.
Examples of the dicarboxylic anhydride used include carboxylic anhydride, oxalic anhydride, maleic anhydride, and phthalic anhydride.
The amount of dicarboxylic anhydride used may be any amount that can sufficiently introduce a carboxylic acid group to the terminal end.
Instead of the above carboxylic acid group or together with the carboxylic acid group, a sulfonic acid group or a phosphoric acid group may be introduced by a known method for acid modification.
Furthermore, these acid groups may be introduced at locations other than the molecular ends of the urethane polymer or polyurethane polyurea.
It is necessary to contain 0.01 to 1.00% by mass of such acid-modified polyurethane resin in the gravure printing ink composition for film, and 0.02 to 2.0% by mass in the solid content of the ink composition. It is necessary to contain 00% by mass.

<Vinyl chloride/vinyl acetate copolymer>
The vinyl chloride/vinyl acetate copolymer that can be blended into gravure printing ink compositions for films contains vinyl chloride monomers and vinyl acetate monomers, which are conventionally used in gravure printing ink compositions, as essential components, and can be added as needed. , fatty acid vinyl monomers such as vinyl propionate, vinyl monochloroacetate, vinyl versatate, vinyl laurate, vinyl stearate, and vinyl benzoate, and monomers having functional groups such as hydroxyl groups were produced by known methods as copolymerization components. Things can be used.
Such a vinyl chloride/vinyl acetate copolymer having a hydroxyl group can be obtained by saponifying a part of the acetate ester moiety and introducing a (meth)acrylic monomer having a hydroxyl group.
In the case of a vinyl chloride/vinyl acetate copolymer having a hydroxyl group obtained by saponifying a part of the acetate ester moiety, a structural unit based on the reactive site of vinyl chloride in the molecule (formula 1 below), acetic acid The physical properties and dissolution behavior of the resin film are determined by the ratio of the structural unit based on the vinyl reaction site (formula 2 below) and the structural unit based on the saponification of the vinyl acetate reaction site (formula 3 below). In other words, the structural units based on the reactive sites of vinyl chloride impart toughness and hardness to the resin film, the structural units based on the reactive sites of vinyl acetate impart adhesiveness and flexibility, and the structural units based on the reactive sites of vinyl acetate impart saponification. The structural units based on the .
Formula 1 -CH ₂ -CHCl-
Formula 2 -CH ₂ -CH(OCOCH ₃ )-
Formula 3 -CH ₂ -CH(OH)-

In addition, from the viewpoint of solubility in organic solvents and printability, which will be described later, to be used in the gravure printing ink composition for films of the present invention, the vinyl chloride/vinyl acetate copolymer has various functional groups in the molecule. It's okay to do so.
Further, when an environmentally friendly solvent is used as the organic solvent, it is preferable that the vinyl chloride/vinyl acetate copolymer has 50 to 200 mgKOH/g of hydroxyl groups. As such commercially available vinyl chloride/vinyl acetate copolymers, it is preferable to use, for example, Solvine A, AL, TA5R, TA2, TA3, TAO, TAOL, and the like.

<Vinyl chloride/acrylic copolymer>
The vinyl chloride/acrylic copolymer that can be blended into the gravure printing ink composition for film has a copolymer of vinyl chloride and an acrylic monomer as a main component, and the form of the copolymer is not particularly limited. For example, the acrylic monomer may be incorporated in the main chain of polyvinyl chloride in a block or random manner, or may be graft copolymerized with the side chain of polyvinyl chloride.

As the acrylic monomer, a (meth)acrylic acid ester, an acrylic monomer having a hydroxyl group, etc. can be used. Examples of (meth)acrylic acid esters include (meth)acrylic acid alkyl esters, and the alkyl group may be linear, branched, or cyclic, but a linear alkyl group is preferable.
For example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate. , 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, (meth)acrylic acid Examples include octadecyl.

Examples of acrylic monomers having hydroxyl groups include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, (meth)acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; , polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, glycol mono(meth)acrylate such as 1,4-cyclohexanedimethanol mono(meth)acrylate, caprolactone-modified (meth)acrylate, hydroxyethyl acrylamide, etc. Can be mentioned.
Moreover, as the acrylic monomer, an acrylic monomer having a functional group other than a hydroxyl group can also be used. Examples of functional groups other than hydroxyl groups include carboxyl groups, amide bonding groups, amino groups, and alkylene oxide groups.
The vinyl chloride/acrylic copolymer preferably has a weight average molecular weight of 10,000 to 70,000.
In addition, from the viewpoint of solubility in environmentally friendly organic solvents and adhesion to substrates, the vinyl chloride/acrylic copolymer has hydroxyl groups in an amount of 50 to 200 mgKOH/g. Preferably.

The gravure printing ink composition for films of the present invention combines a polyurethane resin and (vinyl chloride/vinyl acetate copolymer and/or a vinyl chloride/acrylic copolymer) with a polyurethane resin/(vinyl chloride/vinyl acetate copolymer) (copolymer and/or vinyl chloride/acrylic copolymer) = 95/5 to 45/55 (mass ratio), preferably 92/8 to 70/30.
In addition, for polyurethane resin/(vinyl chloride/vinyl acetate copolymer), the range may be from 90/10 to 75/25, and for polyurethane resin/(vinyl chloride/acrylic copolymer), the range may be from 95/5 to 85/ It may be in the range of 15.
Then, by containing a polyurethane resin and a vinyl chloride/vinyl acetate copolymer and/or a vinyl chloride/acrylic copolymer in a ratio of 95/5 to 45/55, gravure printing for films of the present invention is possible. The ink composition will have better printability and adhesion to the film. Furthermore, if lamination processing is performed, it will have better lamination suitability.
If the above polyurethane resin/(vinyl chloride/vinyl acetate copolymer and/or vinyl chloride/acrylic copolymer) exceeds 95/5, (vinyl chloride/vinyl acetate copolymer and/or vinyl chloride/acrylic copolymer) The proportion of acrylic copolymer) may decrease, and the adhesion to the film may become insufficient.
On the other hand, if the above polyurethane resin/(vinyl chloride/vinyl acetate copolymer and/or vinyl chloride/acrylic copolymer) is less than 45/55, (vinyl chloride/vinyl acetate copolymer and/or chloride copolymer) (vinyl-acrylic copolymer) increases, the printed matter formed using the ink composition of the present invention becomes hard, and there is a possibility that the adhesion to the above-mentioned film may become insufficient.

Therefore, in the present invention, when containing (vinyl chloride/vinyl acetate copolymer and/or vinyl chloride/acrylic copolymer), the above polyurethane resin/(vinyl chloride/vinyl acetate copolymer and/or (vinyl chloride/acrylic copolymer) is preferably 95/5 to 45/55 (mass ratio).
Further, the combined content of the polyurethane resin and vinyl chloride/vinyl acetate copolymer and/or vinyl chloride/acrylic copolymer in the ink composition of the present invention is preferably 5 to 30% by mass. be.
In addition, in the present invention, one type selected from an adhesion improver and an antiblocking agent, preferably an adhesion improver and an antiblocking agent, may be used in combination within a range that does not reduce the performance aimed at by the present invention. preferable.

(Acid group-containing compound with a number average molecular weight of 500 or more)
The acid group-containing compound having a number average molecular weight of 500 or more used in the present invention may be any compound having a polyether structure and/or polyester structure and having an acid group such as a phosphoric acid group or a carboxylic acid group. Note that this is a different compound from acid-modified polyurethane resin.
Examples include phosphoric acid with a polyalkylene ether structure, acid-modified polyethylene glycol, acid-modified polypropylene glycol, acid-modified polycaprolactone, and carboxylic acids with a polyester structure such as poly(3-methyl-1,5-pentanediol) adipic acid. , carboxylic acid modified products of polyalkylene glycol compounds such as polyethylene glycol compounds multimerized with diisocyanate compounds.
Such an acid group-containing compound is not limited to one having an acid group at the end of the molecule, but may also be a compound having an acid group at a location other than the end of the molecule.
In the gravure printing ink composition for films of the present invention, the solid content thereof contains 0.2 to 7.0% by mass, preferably 0.2 to 4.0% by mass, of such acid group-containing compounds. , more preferably 0.2 to 3.0% by mass.

(Adhesion improver)
Examples of the adhesion improver include rosin and its derivatives, chlorinated polypropylene, and dammar resin, and it is desirable to contain at least one kind selected from rosin and its derivatives, and more preferably two or more kinds selected from rosin and its derivatives.

<Rosin and its derivatives>
Examples of the rosin include gum rosin, tall oil rosin, and wood rosin. Generally, rosin is an amber-colored, amorphous resin obtained from pine, and because it is obtained from nature, it is a mixture, but it includes abietic acid, neoabietic acid, palustric acid, pimaric acid, isopimaric acid, sandaracopimaric acid, The dehydroabietic acid component may be isolated and used, and in the present invention, these are also defined as rosin.
Rosin derivatives are compounds obtained by modifying the above-mentioned rosin, and are specifically listed below.
(1) Hydrogenated rosin: A rosin with improved weather resistance by adding hydrogen to conjugated double bonds (hydrogenation).
(2) Disproportionation of rosin: Disproportionation means that two molecules of rosin react, and two molecules of abietic acid with a conjugated double bond are converted into aromatics, one with a single double bond, and the other with a single double bond. It is a denaturation that becomes a molecule. Generally, it has poorer weather resistance than hydrogenated rosin, but it has better weather resistance than untreated rosin.
(3) Rosin-modified phenolic resin: Rosin-modified phenolic resin is often used as the main binder in offset printing inks. Rosin-modified phenolic resin can be obtained by a known manufacturing method.
(4) Rosin ester: This is an ester resin derived from rosin, and has been used as a tackifier for adhesives and adhesives since ancient times.
(5) Rosin-modified maleic acid resin: A product obtained by addition-reacting maleic anhydride to rosin, and also includes a product obtained by esterifying and grafting a hydroxyl group-containing compound such as glycerin with an anhydride group as necessary.
(6) Polymerized rosin: A derivative containing a dimerized resin acid derived from a natural resin rosin.
In addition, known rosin and rosin derivatives can also be used, and these can be used not only alone but also in combination.
Further, the acid value of rosin and its rosin derivative is preferably 120 mgKOH/g or more. When the acid value is 120 mgKOH/g or more, the laminate strength improves. More preferably, the acid value is 160 mgKOH/g or more. Further, the total amount used when blending rosin and its derivatives is preferably 0.1 to 3.0% by mass in solid content of the film gravure printing ink composition.

<Chlorinated polypropylene>
As the chlorinated polypropylene, those having a degree of chlorination of 20 to 50 can be used. Chlorinated polypropylene with a chlorination degree of less than 20 tends to have reduced compatibility with organic solvents. On the other hand, when the degree of chlorination exceeds 50, the adhesion of the chlorinated polypropylene to the film tends to decrease. In the present invention, the degree of chlorination is defined as the mass % of chlorine atoms in the chlorinated polypropylene resin. Further, the chlorinated polypropylene is preferably a modified or unmodified chlorinated polypropylene having a weight average molecular weight of 5,000 to 200,000. When the weight average molecular weight is less than 5000, the adhesiveness of chlorinated polypropylene tends to decrease. On the other hand, when the weight average molecular weight exceeds 200,000, the solubility of the chlorinated polypropylene in organic solvents tends to decrease. Further, the amount of chlorinated polypropylene used when blending is preferably 0.1 to 3.0% by mass in solid content of the gravure printing ink composition for film.

<Dammar resin>
Dammar resin, also written as dammar or dammar, is a type of natural resin derived from plants. Specifically, it is a type of natural resin obtained from plants of the family Dipterocarpaceae or Orchidaceae that grow in Southeast Asia such as Malaysia and Indonesia. When used, it is dissolved in a suitable organic solvent to form a varnish. Since Dammar resin does not contain chlorine, chlorine can be eliminated or reduced compared to when chlorinated polypropylene is used in the printing ink composition. Further, the amount used when blending the Dammar resin is preferably 3.0% by mass or less in solid content mass% of the gravure printing ink composition for film.

(Anti-blocking agent)
Examples of the anti-blocking agent include silica particles, polyethylene wax, fatty acid amide, cellulose acetate butyrate resin, cellulose acetate propionate resin, and nitrified cotton, and one or more of silica particles, polyethylene wax, and fatty acid amide, preferably It is preferable to contain two or more kinds of pigments, and depending on the type of pigment, it is preferable to further contain cellulose acetate butyrate resin, cellulose acetate propionate resin, and nitrified cotton.

<Silica particles>
Silica particles may be naturally produced, synthetic, crystalline, non-crystalline, hydrophobic, or hydrophilic. The silica particles preferably have an average particle diameter of 1.0 to 5.0 μm (the average particle diameter of the silica particles means the particle diameter at 50% (D50) of the integrated value in the particle size distribution, and is calculated using the Coulter Counter method. ). The silica particles may be hydrophilic silica having a hydrophilic functional group on the surface, or may be hydrophobic silica made hydrophobic by modifying the hydrophilic functional group with alkylsilane etc., but hydrophilic particles are preferable; Ink containing silica particles also has the effect of promoting wetting and spreading of the ink during overprinting and improving the overprinting effect (hereinafter sometimes referred to as "trapping property"). The amount of silica particles used in the gravure printing ink composition for film is preferably 0.0 to 3.0% by mass, more preferably 0.1 to 1.0% by mass.

<Polyethylene wax>
The polyethylene wax used has an average particle size in the range of 1.0 to 3.0 μm (the average particle size means the particle size measured with #1 Microtrac UPA manufactured by Honeywell). If the particle size of the polyethylene wax is smaller than 1.0 μm, the slip properties and blocking properties will be reduced, and if the particle size is larger than 3.0 μm, the trapping property will be reduced. Further, the content of polyethylene wax in the gravure printing ink composition for film is preferably in the range of 0.1 to 1.5% by mass. When the content is less than 0.1% by mass, the desired effect cannot be obtained, and when the content is more than 1.5% by mass, gloss tends to decrease.

<Nitrified cotton>
As the nitrified cotton, nitrified cotton conventionally used in gravure printing ink compositions can be used. Nitrified cotton is obtained as a nitric acid ester by reacting natural cellulose with nitric acid to replace three hydroxyl groups in the six-membered ring of the anhydrous glucopyranose group in natural cellulose with nitric acid groups. The nitrified cotton used in the present invention preferably has a nitrogen content of 10 to 13% and an average degree of polymerization of 35 to 90. Specific examples include SS1/2, SS1/4, SS1/8, TR1/16, NCRS-2 (manufactured by KOREA CNC LTD), and the like. The amount of nitrified cotton used in the gravure printing ink composition for film is preferably in the range of 0.1 to 2.0% by mass, depending on the type of pigment.

<Cellulose acetate propionate resin>
As the cellulose acetate propionate resin, resins conventionally used in gravure printing ink compositions can be used.
Cellulose acetate propionate resin is obtained by triesterifying cellulose with acetic acid and propionic acid and then hydrolyzing it. Generally, resins containing 0.6 to 2.5% by weight of acetylation, 42 to 46% by weight of propionylation, and 1.8 to 5% by weight of hydroxyl groups are commercially available. The cellulose acetate propionate resin is preferably used in the gravure printing ink composition for film in an amount of 0.1 to 3.0% by mass, depending on the type of pigment.

<Cellulose acetate butyrate resin>
As the cellulose acetate butyrate resin, resins conventionally used in gravure printing ink compositions can be used.
Cellulose acetate butyrate resin is obtained by triesterifying cellulose with acetic acid and butyric acid and then hydrolyzing it. Generally, resins with a degree of acetylation of 2 to 30% by weight, a degree of butylation of 17 to 53% by weight, and a degree of hydroxyl group of 1 to 5% by weight are commercially available. The amount of cellulose acetate butyrate resin to be used in the gravure printing ink composition for film is preferably in the range of 0.1 to 3.0% by mass, depending on the type of pigment.

<Fatty acid amide>
The fatty acid amide is not particularly limited as long as it has a residue obtained by removing an acid group from a fatty acid and an amide group. Examples of fatty acid amides include monoamides, substituted amides, bisamides, methylolamides, and esteramides, and at least one selected from the group consisting of monoamides, substituted amides, and bisamides because blocking resistance is improved. It is preferable. The amount of fatty acid amide used in the gravure printing ink composition for film is preferably in the range of 0.01 to 1.0% by mass.

- Monoamide: Monoamide is represented by the following general formula (1).
General formula (1) R ₁ -CONH ₂
(In the formula, _R1 represents a residue obtained by removing COOH from a fatty acid.)
Specific examples of monoamides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, oleic acid amide, erucic acid amide, and the like.

- Substituted amide: The substituted amide is represented by the following general formula (2).
General formula (2) R ₂ -CONH-R ₃
(In the formula, R ₂ and R ₃ represent residues obtained by removing COOH from fatty acids, and may be the same or different.)
Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, and the like.

- Bisamide: Bisamide is represented by the following general formula (3) or general formula (4).
General formula (3) R ₄ -CONH-R ₅ -HNCO-R ₆
General formula (4) R ₇ -NHCO-R ₈ -CONH-R ₉
(In the formula, R ₄ , R ₆ , R ₇ , and R ₉ represent residues obtained by removing COOH from a fatty acid, and may be the same or different, and R ₅ and R ₈ are alkylene groups having 1 to 10 carbon atoms. or represents an arylene group)
Specific examples of bisamides include methylene bisstearamide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, and hexamethylene bisstearic acid amide. , hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, ethylene bis oleic acid amide, ethylene bis erucic acid amide, hexamethylene bis oleic acid amide, N,N'-distearyladipic acid amide, N,N'- Examples include distearyl sebacic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide, and the like.

- Methylolamide: Methylolamide is represented by the following general formula (5).
General formula (5) R ₁₀ -CONHCH ₂ OH
(In the formula, _R10 represents a residue obtained by removing COOH from a fatty acid.)
Specific examples of methylolamide include methylol palmitic acid amide, methylol stearic acid amide, methylol behenic acid amide, methylol hydroxystearic acid amide, methylol oleic acid amide, methylol erucic acid amide, and the like.

- Esteramide: Esteramide is represented by the following general formula (6).
General formula (6) R ₁₁ -CONH-R ₁₂ -OCO-R ₁₃
(In the formula, R ₁₁ and R ₁₃ represent a residue obtained by removing COOH from a fatty acid, and may be the same or different, and R ₁₂ represents an alkylene group or arylene group having 1 to 10 carbon atoms.)
Specific examples of esteramides include stearylamide ethyl stearate, oleylamide ethyl stearate, and the like.
The melting point of the fatty acid amide is preferably 50 to 150°C.
Further, as the fatty acid constituting the fatty acid amide, saturated fatty acids having 12 to 22 carbon atoms and/or unsaturated fatty acids having 16 to 25 carbon atoms are preferable, and saturated fatty acids having 16 to 18 carbon atoms and/or saturated fatty acids having 18 to 22 carbon atoms are preferable. More preferred are unsaturated fatty acids. Particularly preferred saturated fatty acids are lauric acid, palmitic acid, stearic acid, behenic acid, and hydroxystearic acid, and particularly preferred unsaturated fatty acids are oleic acid and erucic acid.

(Organic solvent)
The gravure printing ink composition for film of the present invention is oil-based. Examples of the organic solvents used include ketone organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ester organic solvents such as methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, and isobutyl acetate, methanol, Alcohol-based organic solvents such as ethanol, n-propanol, isopropanol, and butanol, and hydrocarbon-based solvents such as toluene and methylcyclohexane can be used.
From the perspective of environmental issues, mixed solvents of ester organic solvents, alcohol-based organic solvents, and ketone-based organic solvents, or mixed solvents of ester-based organic solvents and alcohol-based organic solvents that are more environmentally friendly are recommended. It is preferable to use
Furthermore, the gravure printing ink composition for films of the present invention preferably contains 0.1 to 20% by mass of a glycol ether organic solvent in 100% by mass of the organic solvent in order to improve wetting and spreading properties. Specific examples of glycol ether organic solvents include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, and ethylene glycol. Examples include monoisobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol mono-n-propyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and diethylene glycol diethyl ether.

The gravure printing ink composition for films of the present invention preferably contains water from the viewpoints of alleviating printing defects caused by static electricity, preventing plate fogging, and cell reproducibility. The amount of water used in the gravure printing ink composition for film is preferably 10% by mass or less, and more preferably in the range of 0.1 to 5.0% by mass.

<Other materials>
Various additives such as a pigment dispersant, an antistatic agent, and a plasticizer can be further added to the gravure printing ink composition for films of the present invention.
A known method can be used to manufacture the ink composition using the above constituent materials. Specifically, for example, a mixture of a pigment, a binder resin, an organic solvent, and if necessary a pigment dispersant is milled using a high-speed mixer, a ball mill, a sand mill, an attritor, etc., and then a thiocyanate and a prescribed amount are ground. It can be obtained by adding and mixing the rest of the materials such as additives.
If the alkylimidazoline and/or N,N-dibutyl-N-ethyl-1-butanaminium/ethyl sulfate are not added in the above manufacturing method, they can be added during printing. Further, a metal tetraalkoxide and/or a hydroxy acid may or may not be contained.

(Printing method using gravure printing ink composition for film and laminate obtained thereby)
Next, a method for obtaining a laminated printed matter using the ink composition of the present invention will be explained. The gravure printing ink composition for films of the present invention can also be used for purposes other than lamination.
The method for obtaining the laminated printed matter includes at least the following printing method. For example, a gravure printing ink composition for lamination is printed at least once or more by a gravure printing method on a resin film that is a known base material for lamination. Next, another ink composition for gravure laminate printing is printed by a gravure printing method on any part of the surface side (lower layer side when viewed from the surface layer after final lamination) of the printing ink layer for gravure laminate formed by these printings. and dry it with a hair dryer.
A laminated printed material for packaging bags and the like can be obtained by laminating a resin film or the like by various methods on the side of the printed material obtained by the above method on which the ink composition for gravure lamination printing is applied. This lamination method includes the extrusion lamination method, in which a molten polymer is laminated after coating the surface of the printed matter with an anchor coating agent or without coating, and the extrusion lamination method, in which the surface of the printed matter is coated with an adhesive, and then a film-like A dry lamination method for bonding polymers can be used.

In the extrusion lamination method described above, after applying an anchor coating agent such as a titanium-based, urethane-based, imine-based, or polybutadiene-based anchor coating agent to the surface of a printed matter containing a layer of an ink composition, a known extrusion lamination machine is used. This is a method in which molten polymers are laminated, and the molten resin can also be used as an intermediate layer to laminate other materials in the form of a sandwich.
As the molten polymer used in the extrusion lamination method, conventionally used resins such as low density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, etc. can be used. Among these, the effect of the present invention is enhanced when low density polyethylene is used, which tends to generate carbonyl groups by oxidation during melting.
The dry lamination method described above is a method in which a urethane-based, isocyanate-based adhesive, etc., is applied to the surface of a layer made of a gravure lamination printing ink composition, and then a resin film is laminated using a known dry laminating machine. . As the resin for the film used in the dry lamination method, polyethylene, unstretched polypropylene, etc. can be used. In particular, in order to obtain a packaging material used for retort applications, aluminum foil may be sandwiched between the base material and the resin film to be laminated. Such laminated products can also be used for boiling and retort applications after being made into bags and filled with contents.
Examples of the resin film used at this time include stretched and unstretched polyolefins such as polyethylene and polypropylene, polyester, nylon, cellophane, and vinylon. Furthermore, regarding these resin films, it is also possible to use films obtained by processing such as coating and kneading of an antifogging agent, surface coating and kneading of a matting agent, and the like.
Further, as the resin film, a film formed by laminating a barrier layer formed by metal vapor deposition and coating with a barrier resin on various printing plastic films, etc. can be used.

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited only to these Examples. In addition, unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."
(Acid group-containing compound with a number average molecular weight of 500 or more)
(Reaction product of PEG2000 and succinic anhydride)
200 parts (0.1 mol) of polyethylene glycol (PEG2000) with a number average molecular weight of 2000 and 20 parts (0.2 mol) of succinic anhydride were placed in a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, and nitrogen The reaction was carried out at 90 to 100°C while introducing gas. The end point of the reaction was confirmed by the disappearance of the peak derived from the acid anhydride group in infrared spectroscopy.

(Reaction product of PEG1000 and succinic anhydride)
100 parts (0.1 mol) of polyethylene glycol (PEG1000) with a number average molecular weight of 1000 and 20 parts (0.2 mol) of succinic anhydride were placed in a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas introduction tube, and nitrogen The reaction was carried out at 90 to 100°C while introducing gas. The end point of the reaction was confirmed by the disappearance of the peak derived from the acid anhydride group in infrared spectroscopy.

(Reaction product of PEG400 and succinic anhydride)
40 parts (0.1 mol) of polyethylene glycol (PEG400) with a number average molecular weight of 400 and 20 parts (0.2 mol) of succinic anhydride were placed in a four-neck flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, and nitrogen The reaction was carried out at 90 to 100°C while introducing gas. The end point of the reaction was confirmed by the disappearance of the peak derived from the acid anhydride group in infrared spectroscopy.

(Reactant of polyester and succinic anhydride)
In a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, 200 parts (0.1 mol) of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 2000 and 20 parts of succinic anhydride ( 0.2 mol) and reacted at 90 to 100°C while introducing nitrogen gas. The end point of the reaction was confirmed by the disappearance of the peak derived from the acid anhydride group in infrared spectroscopy.

(Reaction product of PEG2000 and pyromellitic anhydride)
400 parts (0.2 mol) of polyethylene glycol (PEG2000) with a number average molecular weight of 2000 and 21.8 parts (0.1 mol) of pyromellitic anhydride were placed in a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas introduction tube. The reaction was carried out at 110 to 120° C. while introducing nitrogen gas. The end point of the reaction was confirmed by the disappearance of the peak derived from the acid anhydride group in infrared spectroscopy.

(Phosphate ester compound 1)
By the method described in JP-A No. 2019-31433 (paragraphs 0038 and 0039), the compound No. Synthesis was performed using the composition (5) to obtain phosphoric acid ester compound 1.

(Reaction product of PEG200 and succinic anhydride)
20 parts (0.1 mol) of polyethylene glycol (PEG200) with an average molecular weight of 200 and 20 parts (0.2 mol) of succinic anhydride were placed in a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, and nitrogen gas was added. The reaction was carried out at 90 to 100°C while introducing . The end point of the reaction was confirmed by the disappearance of the peak derived from the acid anhydride group in infrared spectroscopy.

[Ink creation]
(Polyurethane resin varnish)
200 parts of 3-methyl-1,5-pentylene adipate diol with a number average molecular weight of 2000 and 44.4 parts of isophorone diisocyanate were charged into a four-necked flask equipped with a stirrer, a cooling tube, and a nitrogen gas inlet tube, and nitrogen gas was added. The mixture was reacted at 100 to 105°C for 6 hours while introducing . After cooling to near room temperature, adding 243 parts of toluene, 243 parts of methyl ethyl ketone, and 122 parts of isopropanol, 13.6 parts of isophoronediamine was added to cause a chain extension reaction, and further 2.4 parts of ethylenediamine was added to stop the reaction. A polyurethane resin varnish (solid content 30%, weight average molecular weight of polyurethane resin 16,000, functional group reactable with isocyanate group contained in the molecule = primary amino group) was obtained.
30.0 parts by mass of this polyurethane resin varnish, 40.0 parts by mass of titanium oxide (R-960, manufactured by DuPont), and 30.0 parts by mass of a mixed solvent (toluene: methyl ethyl ketone: isopropanol = 40:40:20). The mixture was mixed, and an acid group-containing compound was added as shown in Table 2 below (% by mass in the ink composition) to obtain a white ink composition.

<Print>
100 parts by mass of each ink composition of Examples and Comparative Examples was diluted with a mixed solvent (ethyl acetate/propyl acetate/isopropyl alcohol = 50/25/25, mass ratio), and the viscosity was measured using Zahn Cup No. 3 manufactured by Rigosha. I adjusted it to 15 seconds. The diluted ink compositions described above were printed on the treated surfaces of various films using a gravure printing machine under the following conditions and dried to obtain printed matter.
For evaluation of no white overlapping, each of the above white inks was printed on an OPP film. For the evaluation of white overlapping, printing was performed using "Bell Color R Indigo 800" (manufactured by Sakata Inx Co., Ltd.) on an OPP film, and each of the above white inks was overprinted thereon.
The specific evaluation method is shown below.

(Printing method/printing conditions)
Room environment during printing: temperature 25℃, humidity 50%
Coating machine: Gravure printing machine Coating speed: 150m/min
Printing plate: Direct 175 line 28μm solid plate Drying temperature: 55℃
(Various films)
OPP: biaxially oriented polypropylene film treated with corona discharge,
Manufactured by Toyobo Co., Ltd. P-2161, thickness 25μm

(Extrusion laminate strength)
Each of the printed matter of Examples and Comparative Examples was treated with a polyethyleneimine anchor coating agent (Toyo Morton Co., Ltd., EL-420), and then laminated with molten polyethylene using an extrusion laminating machine to obtain a laminated product. . These laminated products were aged at 40° C. for 1 day and then cut into 15 mm width pieces, and the T-peel strength (g/15 mm) was measured as the extrusion laminate strength using a peel tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.). The results are shown in Table 2.
○: 100g/15mm or more △: 50g/15mm or more but less than 100g/15mm ×: Less than 50g/15mm

As described in each example, when an ink composition containing an acid group-containing compound in a polyurethane resin was used, sufficiently high lamination strength could be obtained in the white overlapping area.
On the other hand, in Comparative Example 1, which used an ink composition in which the polyurethane resin did not contain an acid group-containing compound, sufficient lamination strength could not be obtained in the white overlapping area.
Furthermore, even in Comparative Example 2 in which an acid group-containing compound with a low number average molecular weight was used, sufficiently high lamination strength could not be obtained in the white overlapping portion.
Furthermore, in the cases of Examples 1 to 5 and 7, in which the acid group-containing compound simultaneously has a polyethylene glycol structure, the whiteness is higher than that in the case where the acid group-containing compound does not simultaneously have a polyethylene glycol structure, for example, as in Example 6. Excellent extrusion laminate strength when stacked.

Claims (5)

A gravure printing ink composition for film containing a pigment, a polyurethane resin, and an organic solvent,
The solid content of the gravure printing ink composition for film contains 0.2 to 7.0% by mass of an acid group-containing compound having a number average molecular weight of 500 or more,
The polyurethane resin has an amine value of 1.0 to 15.0 mgKOH/g,
A gravure printing ink composition for film, wherein the acid group-containing compound has a theoretical acid value of 27 or more and is one or more selected from the following (1) to (5) :
(1) Phosphoric acid with polyalkylene ether structure
(2) Acid-modified polyethylene glycol
(3) Acid-modified polypropylene glycol
(4) Acid-modified polycaprolactone
(5) A carboxylic acid modified product of a polyalkylene glycol compound multimerized with a diisocyanate compound . The gravure printing ink composition for films according to claim 1, wherein the acid group-containing compound has a polyether structure . The gravure printing ink composition for film according to claim 2, wherein the acid group-containing compound has a polyoxyethylene structure. The gravure printing ink composition for films according to any one of claims 1 to 3, wherein the acid group of the acid group-containing compound is one or more selected from carboxylic acid, phosphoric acid, and sulfonic acid. The gravure printing ink composition for film according to any one of claims 1 to 4, wherein the pigment contains titanium oxide.