JP7461222B2 - Gravure printing ink composition for film, printing method, printed matter and laminate - Google Patents

Description

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

Packaging materials using various plastic films are used for food, confectionery, household goods, pet food, etc., from the viewpoints of design, economy, content protection, transportability, etc. Furthermore, gravure printing or flexographic printing is applied to many packaging materials with the intention of adding designs, messages, etc. that will appeal to consumers.
In order to obtain the desired packaging material, front printing is performed in which printing is done on the front side of the base film of the packaging material, or back printing is performed in which an adhesive or anchor agent is applied as necessary to the printed surface on the back side of the base film of the packaging material and the film is laminated.
In reverse printing, colored inks and white ink are printed in sequence 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), and then a polyethylene film, 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 laminate strength.
For this reason, although it is possible to include a chlorinated polyolefin in the ink composition, even if the content is increased, there are cases in which a sufficiently high laminate strength is not achieved.
Also, as in Patent Document 1, a metal alkoxide and a hydroxy acid are incorporated into a urethane resin to improve the laminate strength. In this case, the stability over time is said to be excellent, but since the properties of the metal alkoxide itself are poor in storage stability, it is preferable not to add them.
Patent Document 2 describes a printing ink composition containing an imidazoline salt of an amide of a copolymer of an olefin and an unsaturated dibasic acid with an amine having a branched alkyl group having from 6 to 10 carbon atoms, and this imidazoline salt is contained to improve the dispersibility of the pigment.
US Pat. No. 5,399,633 describes a pigment dispersion in which alkyl imidazolines are exemplified as one of a wide variety of surfactants that may be used.

JP 2017-061683 A JP 2018-168285 A JP 2019-116568 Publication

The objective of the present invention is to provide a gravure printing ink composition for film that provides excellent lamination strength for the laminate film on the printed 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 an alkylimidazoline compound and/or an alkenylimidazoline compound in the solid content of the gravure printing ink composition for films.
2. 2. The gravure printing ink composition for films according to 1, wherein the alkylimidazoline compound and/or alkenylimidazoline compound is a compound represented by the following formula (1) and/or formula (2).
Formula (1)
Formula (2)
In formulas (1) and (2), R is an alkyl group and/or alkenyl group having 6 to 35 carbon atoms, P is a hydroxyalkyl group having 2 to 6 carbon atoms, and A is a halogen.
3. The gravure printing ink composition for films according to 1 or 2, which contains the alkylimidazoline compound and/or the alkenylimidazoline compound in an amount of 0.2 to 7.0% by mass in the solid content of the gravure printing ink composition for films.

According to the present invention, by selecting an alkyl imidazoline compound and/or an alkenylimidazoline compound from among surfactants and pigment dispersants, an effect of improving extrusion laminate strength, which is different from the inherent effect of the surfactant or pigment dispersant, can be achieved.
Furthermore, even if a film such as OPP is laminated onto the surface printed with the white ink composition, a sufficiently high laminate 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, and a film containing an alkylimidazoline compound and/or an alkenylimidazoline compound in the solid content of the gravure printing ink composition for films. This is a gravure printing ink composition. 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 inorganic and organic pigments that can be contained in ink compositions for reverse printing lamination can be used.
Examples of inorganic pigments include color pigments such as titanium oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, carbon black, and graphite, and examples of extender pigments include silica particles, calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, and talc. Of these, it is preferable to use titanium oxide as a white pigment.
Examples of the organic pigment 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.

(Alkylimidazoline compounds and alkenylimidazoline compounds)
Alkylimidazoline compounds and alkenylimidazoline compounds are compounds in which the hydrogen atom bonded to one carbon atom of the imidazoline ring is substituted with an alkyl group or alkenyl group, and are compounds that can also be used as pigment dispersants and surfactants. be. Among these, compounds represented by the following formula (1) and/or formula (2) are preferred. Note that formula (1) is a quaternary salt, and formula (2) is its nonionic salt.
Formula (1)
Formula (2)
In formula (1) and formula (2), R is a linear or branched alkyl group or alkenyl group having 6 to 35 carbon atoms, P is a hydroxyalkyl group having 2 to 6 carbon atoms, and A is a halogen. .
When R is an alkyl group, for example, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group. , nonadecyl group, icosyl group, henicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, triacontyl group, hentriacontyl group, dotriacontyl group, tritriacontyl group, These include a tetratriacontyl group, a pentatriacontyl group, a myristole group, a palmitoleyl group, an oleyl group, a linoyl group, a linoleyl group, a ricinoleyl group, an isostearyl group, and the like.
When R is an alkenyl group, for example, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group. , nonadecenyl group, icosenyl group, henicosenyl group, docosenyl group, tricosenyl group, tetracosenyl group, pentacosenyl group, hexacosenyl group, heptacosenyl group, octacosenyl group, nonacosenyl group, triacontenyl group, hentriacontenyl group, dotriacontenyl group , tritriacontenyl group, tetratriacontenyl group, pentatriacontenyl group, ministrenyl group, palnitrenyl group, olenyl group, ninolyl group, linolenyl group, isosteanyl group, and the like.
Among the alkylimidazoline compounds and/or alkenylimidazoline compounds represented by the formula (1), those in which R is a straight-chain alkyl group having 7 to 21 carbon atoms or an alkenyl group having 7 to 21 carbon atoms are preferable, and those in which R is a straight chain alkyl group having 7 to 21 carbon atoms are preferable. Straight-chain alkyl groups having 13 to 19 carbon atoms and alkenyl groups having 13 to 19 carbon atoms are preferred.
Further, P is preferably a hydroxyalkyl group having 2 to 6 carbon atoms, more preferably a hydroxyalkyl group having 2 to 3 carbon atoms, and most preferably a 2-hydroxyethyl group.
A is preferably halogen, more preferably chlorine.
The gravure printing ink composition for films of the present invention preferably contains an alkylimidazoline compound and/or an alkenylimidazoline compound in the solid content of 0.2 to 7.0% by mass, more preferably 0.2 to 7.0% by mass. The content is 4.0% by mass, more preferably 0.2 to 3.0% by mass.
In addition, one type of these compounds may be contained, or two or more types may be contained.

(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 is not modified with an acid. The polyurethane resin that is not modified with an acid 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 terminals and/or other positions within the molecule. As such a polyurethane resin that is not modified with an acid, a polyurethane resin that is generally used in printing inks can be used.
Among them, from the viewpoints of the ink stability over time, adhesion, and lamination suitability, polyurethane resins having amino groups (having an amine value) are preferred.Of the polyurethane resins having amino groups, polyurethane resins having at least one type selected from a primary amino group, a secondary amino group, and a tertiary amino group at the molecular terminal are more preferred.
More preferred is a polyurethane resin having a hydroxyl group and at least one type of amino group selected from a primary amino group, a secondary amino group and a tertiary amino group at the molecular terminal.

The non-acid-modified polyurethane resin has a specific functional group such as the amino group, so that the gravure printing ink composition for films of the present invention has excellent printability and adhesion to films. become.
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 an organic diisocyanate component and a polymeric 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.

(non-acid-modified polyurethane polyurea resin)
The non-acid-modified polyurethane polyurea resin has at least one type of amino group selected from a primary amino group and a secondary amino group at the molecular terminal.
More preferred is a polyurethane polyurea resin that has a hydroxyl group and at least one type selected from a primary amino group and a secondary amino group at the molecular terminal and is not modified with an acid.
As these polyurethane polyurea resins, polyurethane resins obtained by synthesizing a urethane prepolymer by reacting an organic diisocyanate compound with a polymeric diol compound and reacting this with a chain extender and a reaction terminator described below can be suitably used.

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

All of the organic diisocyanate compounds used may be isophorone diisocyanate, but other organic diisocyanate compounds can be used in combination.
Other organic diisocyanate compounds include aromatic diisocyanate compounds such as 1,3- and/or 1,4-phenylene diisocyanate, 4,4-diisocyanatobiphenyl, 3,3-dimethyl-4,4-diisocyanatobiphenyl, and tolylene diisocyanate; alicyclic diisocyanate compounds such as 1,4-cyclohexane diisocyanate, cyclohexylene diisocyanate, and methylcyclohexylene diisocyanate (hydrogenated TDI); and ethylene diisocyanate. Examples of the organic diisocyanate compounds include aliphatic diisocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate, and aromatic aliphatic diisocyanate compounds such as m- and/or p-xylylene diisocyanate (XDI) and α,α,α',α'-tetramethylxylylene diisocyanate. These organic diisocyanate compounds can be used alone or in combination of two or more. Among these, alicyclic diisocyanate compounds, aliphatic diisocyanate compounds, and aromatic aliphatic diisocyanate compounds are more preferred.
When other organic diisocyanate compounds are used in combination, the number of isocyanate groups of the other organic diisocyanate compounds can be 50% or less, more preferably 30% or less, and even more preferably 10% or less, of the total number of isocyanate groups of all the organic diisocyanate compounds.
Alternatively, the amount of the other organic diisocyanate compounds is 50 parts by mass or less, more preferably 30 parts by mass or less, and further preferably 10 parts by mass or less, based on 100 parts by mass of the total organic diisocyanate compounds.

(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.

Furthermore, the polymer diol compound may be one containing 3-methyl-1,5-pentylene adipate diol. Among them, the number average molecular weight is preferably 1,000 to 8,000, more preferably 1,000 to 5,500, and even more preferably 1,000 to 4,000.
In this case, the following polymer diol compounds can be used in combination.
Examples of polymeric diol compounds other than 3-methyl-1,5-pentylene adipate diol include polyester diols obtained by condensation reaction of one or more dibasic acids such as adipic acid, sebacic acid, phthalic anhydride, etc. with one or more glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, etc., polyester diol compounds such as polycaprolactone diols, and further polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polyether diol compounds such as alkylene oxide adducts of bisphenol A with ethylene oxide, propylene oxide, etc. These polymeric diol compounds can be used alone or in combination of two or more.

Among the above, 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 1,000 to 8,000 obtained by condensation reaction of adipic acid and 3-methyl-1,5-pentanediol is preferred, and 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 1,000 to 4,000 is more preferred.
When other polymer diol compounds are used in combination, the number of hydroxyl groups of the other polymer diol compounds can be 70% or less, more preferably 55% or less, and even more preferably 40% or less, based on the total number of hydroxyl groups of all the polymer diol compounds.
Alternatively, the amount of the other polymer diol compounds is 50 parts by mass or less, more preferably 35 parts by mass or less, and further preferably 20 parts by mass or less, based on 100 parts by mass of the total polymer diol compounds.
When the organic solvent of the film gravure printing ink composition is a mixed solvent system of an ester-based solvent and an alcohol-based solvent (hereinafter sometimes referred to as a "mixed liquid") described below, using a polyether diol compound, preferably polypropylene glycol, as the polymer diol compound tends to increase the solubility of the resulting polyurethane resin and also tends to improve printing suitability such as gradation reproduction and anti-fogging properties, which is preferable in that it enables the ink to be designed widely in accordance with the required performance.

<Non-acid-modified biomass polyurethane polyurea resin>
In addition, the polyurethane resin may contain a biomass polyurethane polyurea resin that is not modified with an acid, taking into consideration the environmental aspect. The biomass polyurethane polyurea resin that is not modified with an acid will be described below. In the description of the biomass polyurethane polyurea resin that is not modified with an acid, the description common to the above-mentioned polyurethane polyurea resin that is not modified with an acid will be omitted as appropriate.
The non-acid-modified biomass polyurethane polyurea resin is a polyurethane resin containing a biomass-derived (plant-derived) component. The non-acid-modified biomass polyurethane resin can contribute to preventing global warming and reducing the environmental load compared to the case of using other exhaustible resources. The non-acid-modified biomass polyurethane polyurea resin is preferably obtained by synthesizing a urethane prepolymer by reacting a biopolyester polyol compound with an organic diisocyanate compound, and reacting this with a chain extender and a reaction terminator as necessary, and more preferably the isocyanate compound is a plant-derived bioisocyanate.

(Isocyanate Compounds)
In addition to the organic diisocyanates described in the above non-acid-modified polyurethane polyurea resin, diisocyanates derived from vegetable oils can be used. The organic diisocyanate compounds derived from vegetable oils can be obtained by converting a divalent carboxylic acid derived from a plant into a terminal amino group by acid amidation and reduction, and then reacting with phosgene to convert the amino group into an isocyanate group. Examples of bio-polyisocyanates derived from plants include dimer acid diisocyanate (DDI), octamethylene diisocyanate, and decamethylene diisocyanate. In addition, plant-derived isocyanate compounds can be obtained by using plant-derived amino acids as raw materials and converting their amino groups into isocyanate groups. For example, lysine diisocyanate (LDI) can be obtained by methyl esterifying the carboxyl group of lysine, and then converting the amino group into an isocyanate group. In addition, 1,5-pentamethylene diisocyanate can be obtained by decarbonating the carboxyl group of lysine, and then converting the amino group into an isocyanate group.

(Bio polyester polyol compound)
The biopolyester polyol compound will be explained below.
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.
In addition, a non-acid-modified polyurethane polyurea resin obtained by reacting a polyester polyol compound containing a bio-polyester polyol compound with the above-mentioned specific isocyanate compound is mixed with the non-acid-modified polyurethane polyurea resin of the present invention. It can also be used as
Therefore, as the above biopolyester polyol compound, 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, the carboxylic acid compound is sebacic acid, succinic acid, lactic acid, glutaric acid, dimer acid, etc. 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. In addition, 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 directly dehydrating and condensing plant-derived sebacic acid and plant-derived 1,3-propanediol. Also, polybutylene succinate polyol is obtained by directly dehydrating and condensing plant-derived succinic acid and plant-derived 1,4-butanediol.
These biopolyester polyol compounds may be used alone or in combination.
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, calculated as solid content, of the total urethane prepolymer.

(Chain extender and reaction terminator)
Next, the chain extender and reaction terminator used in the non-acid-modified polyurethane polyurea resin and the non-acid-modified biomass polyurethane polyurea resin will be explained.
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'-dicyclohexylmethane diamine, 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.

As a method for producing the above-mentioned non-acid-modified polyurethane polyurea resin and non-acid-modified biomass polyurethane polyurea resin, a known method for producing 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 non-acid-modified polyurethane polyurea resin and non-acid-modified biomass polyurethane polyurea resin is preferably 10,000 to 70,000, more preferably 20,000 to 60,000. is more preferable.
Furthermore, in order to increase appropriate flexibility and lamination strength, a polyurethane resin having no urea bond and having a mass average molecular weight of 1,000 to 70,000 may be blended as the polyurethane resin.

(Reaction of organic diisocyanate compound with polymeric diol compound)
Furthermore, the use ratio of the organic diisocyanate compound and the polymer diol compound when reacting them is such that the equivalent ratio of isocyanate groups:hydroxyl groups (isocyanate index) is usually in the range of 1.2:1 to 3.0:1, more preferably 1.3:1 to 2.0:1. If the isocyanate index is less than 1.2, the resulting polyurethane polyurea resin will tend to be a soft non-acid-modified polyurethane polyurea resin or a non-acid-modified biomass polyurethane polyurea resin, and there is a possibility that the blocking resistance and the like will be low when the ink composition is printed. In this case, it may be necessary to use the ink composition in combination with another hard resin.

A catalyst can be used during the reaction between the organic diisocyanate compound and the polymeric diol compound to obtain the non-acid-modified polyurethane polyurea resin and non-acid-modified biomass 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. , Jibutyl tin dicrosside, dibut tin oxide, dibut tin jobromide, jibutyl tin jimraid, jibutyl tin jirate, jibutyl tin jia setan, tributyl tin acetate, triethyl tin chloride, trientille tin etoxide, tsure. Libutyl tin etoxide, geokuchil tin oxyide , 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.

(Ketiminated polyurethane polyurea resin, ketiminated biomass polyurethane polyurea resin)
Ketiminated polyurethane polyurea resin and ketiminated biomass polyurethane polyurea resin use a ketimine compound obtained by ketiminating a polyamine compound in advance with an excessive amount of a ketone compound among the chain extenders and/or reaction terminators mentioned above. Then, a non-acid-modified polyurethane polyurea resin and a non-acid-modified biomass polyurethane polyurea resin are produced using the chain extender and/or 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, alcohol compounds can be used as solvents other than ketone compounds. 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 extension reaction or the fact that the polyurethane polyurea resin and biomass polyurethane polyurea resin have no odor.
The present invention relates to an ink composition containing a ketiminated polyurethane polyurea resin and/or a biomass polyurethane polyurea resin obtained through a process of chain extension and reaction termination using a chain extender and/or a reaction terminator. The ink composition and printed matter may not produce a 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 ketiminated polyurethane polyurea resin from urethane prepolymer, and ketiminated biomass polyurethane polyurea resin>
The urethane prepolymer obtained by the above method can be subjected to a chain extension and/or reaction termination reaction with a ketimine compound to obtain the ketiminated polyurethane polyurea resin and ketiminated biomass polyurethane polyurea resin of the present invention.
That is, a solvent is added, if necessary, to the reaction product of the organic diisocyanate compound and the polymer diol compound, and further, the ketimine chain extender and/or reaction terminator are added to carry out the reaction.
When a solvent is used, an ester-based solvent and/or an alcohol-based solvent is preferred, a mixture of an ester-based solvent and an alcohol-based solvent is more preferred, propyl acetate and isopropyl alcohol are even more preferred, and a mass ratio of propyl acetate:isopropyl alcohol in the range of 1 to 5:1 is most preferred.

[Acid-modified polyurethane resin, acid-modified biomass polyurethane resin]
As the polyurethane resin in the present invention, an acid-modified polyurethane resin and/or an acid-modified bio-polyurethane resin can also be employed. It may be used with the above-mentioned non-acid-modified polyurethane resins and/or non-acid-modified biomass polyurethane resins, or may be used alone with acid-modified polyurethane resins and/or acid-modified biomass polyurethane resins, or with acid-modified acid-modified biomass polyurethane resins. Only untreated polyurethane resins and/or unacid-modified biomass polyurethane resins may be used.
Acid-modified polyurethane resins and acid-modified biomass polyurethane resins are urethane prepolymers or polyurethane polyureas obtained by the same method as the above-mentioned manufacturing method, but the terminal hydroxyl groups and amino groups are anhydrous. An acid-modified polyurethane resin or an acid-modified biomass polyurethane resin is obtained by reacting with dicarboxylic acid and introducing a carboxylic acid group at the end.
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 and/or acid-modified biomass polyurethane resin in the gravure printing ink composition for film, and the ink composition It is necessary to contain 0.02 to 2.00% by mass in the solid content.

<Vinyl chloride/vinyl acetate copolymer>
The vinyl chloride-vinyl acetate copolymer that can be incorporated in the gravure printing ink composition for film may be one produced by a known method using the vinyl chloride monomer and vinyl acetate monomer conventionally used in gravure printing ink compositions as essential components, and, if necessary, a fatty acid vinyl monomer such as vinyl propionate, vinyl monochloroacetate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl benzoate, or a monomer having a functional group such as a hydroxyl group, as a copolymerization component.
A vinyl chloride-vinyl acetate copolymer having a hydroxyl group can be obtained by partially saponifying the acetate 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 portion of the acetate moiety, the film properties and dissolution behavior of the resin are determined by the ratio of the constituent units based on the reactive sites of vinyl chloride in the molecule (formula 1 below), the constituent units based on the reactive sites of vinyl acetate (formula 2 below), and the constituent units based on the saponification of the reactive sites of vinyl acetate (formula 3 below). That is, the constituent units based on the reactive sites of vinyl chloride impart toughness and hardness to the resin film, the constituent units based on the reactive sites of vinyl acetate impart adhesion and flexibility, and the constituent units based on the saponification of the reactive sites of vinyl acetate impart good solubility to environmentally friendly organic solvent systems of the ink.
Formula 1 _-CH2 -CHCl-
Formula 2 -CH2 _- CH( _OCOCH3 )-
Formula 3 -CH2 _- CH(OH)-

From the viewpoints of solubility in organic solvents described below and printability used in the film gravure printing ink composition of the present invention, the vinyl chloride-vinyl acetate copolymer may have various functional groups in the molecule.
When an environmentally friendly solvent is used as the organic solvent, the vinyl chloride-vinyl acetate copolymer preferably has a hydroxyl group concentration of 50 to 200 mg KOH/g. Commercially available products of such vinyl chloride-vinyl acetate copolymers include, for example, Solvine A, AL, TA5R, TA2, TA3, TAO, and TAOL.

<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.

The acrylic monomer may be a (meth)acrylic acid ester, an acrylic monomer having a hydroxyl group, etc. Examples of the (meth)acrylic acid ester include a (meth)acrylic acid alkyl ester, and the alkyl group may be linear, branched, or cyclic, but is preferably a linear alkyl group.
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, and octadecyl (meth)acrylate.

Examples of acrylic monomers having a hydroxyl group include (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; glycol mono(meth)acrylates such as polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and 1,4-cyclohexanedimethanol mono(meth)acrylate; caprolactone-modified (meth)acrylate; and hydroxyethylacrylamide.
The acrylic monomer may also have a functional group other than a hydroxyl group, such as a carboxyl group, an amide bond, an amino group, or an alkylene oxide group.
The vinyl chloride-acrylic copolymer preferably has a weight average molecular weight of 10,000 to 70,000.
In addition, from the viewpoints of solubility in an environmentally friendly organic solvent and adhesion to a substrate, it is preferable that the vinyl chloride-acrylic copolymer has hydroxyl groups such that the hydroxyl group concentration is 50 to 200 mg KOH/g.

The gravure printing ink composition for film of the present invention can contain a polyurethane resin and (vinyl chloride-vinyl acetate copolymer and/or vinyl chloride-acrylic copolymer) in a mass ratio of polyurethane resin/(vinyl chloride-vinyl acetate copolymer and/or vinyl chloride-acrylic copolymer)=95/5 to 45/55, preferably 92/8 to 70/30.
In addition, the ratio of polyurethane resin/(vinyl chloride-vinyl acetate copolymer) may be in the range of 90/10 to 75/25, and the ratio of polyurethane resin/(vinyl chloride-acrylic copolymer) may be in the range of 95/5 to 85/15.
By containing the polyurethane resin and the vinyl chloride-vinyl acetate copolymer and/or the vinyl chloride-acrylic copolymer in a ratio of 95/5 to 45/55, the gravure printing ink composition for film of the present invention has even better printability and adhesiveness to the film. Furthermore, when lamination processing is performed, it has even better lamination suitability.
If the ratio of the polyurethane resin to the vinyl chloride-vinyl acetate copolymer and/or the vinyl chloride-acrylic copolymer exceeds 95/5, the proportion of the vinyl chloride-vinyl acetate copolymer and/or the vinyl chloride-acrylic copolymer may become small, and the adhesion to the film may become insufficient.
On the other hand, when the ratio of the polyurethane resin to the vinyl chloride-vinyl acetate copolymer and/or the vinyl chloride-acrylic copolymer is less than 45/55, the proportion of the vinyl chloride-vinyl acetate copolymer and/or the vinyl chloride-acrylic copolymer becomes high, and the printed matter formed using the ink composition of the present invention becomes hard, and the adhesion to the film may also become insufficient.

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.
Furthermore, the present invention can contain one or more selected from adhesion improvers and antiblocking agents within a range that does not reduce the performance aimed at by the present invention. Preferably, the adhesion improvers and antiblocking agents are combined. It is preferable to use them together.

(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: A rosin-modified phenolic resin is sometimes used as the main binder. 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>
The chlorinated polypropylene may have a chlorination degree of 20 to 50. A chlorinated polypropylene having a chlorination degree of less than 20 tends to have a decreased compatibility with organic solvents. On the other hand, when the chlorination degree exceeds 50, the chlorinated polypropylene tends to have a decreased adhesiveness to the film. In the present invention, the chlorination degree is defined as the mass % of chlorine atoms in the chlorinated polypropylene resin. 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 5,000, the chlorinated polypropylene tends to have a decreased adhesiveness. On the other hand, when the weight average molecular weight exceeds 200,000, the chlorinated polypropylene tends to have a decreased solubility in organic solvents. The amount of the chlorinated polypropylene to be used when blending is preferably 0.1 to 3.0 mass % in terms of solid mass % of the film gravure printing ink composition.

<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 anti-blocking agents include silica particles, polyethylene wax, fatty acid amides, cellulose acetate butyrate resin, cellulose acetate propionate resin, soluble nitrocellulose, etc. It is preferable to contain one or more, preferably two or more, of silica particles, polyethylene wax, and fatty acid amides, and depending on the type of pigment, it is preferable to further contain cellulose acetate butyrate resin, cellulose acetate propionate resin, and soluble nitrocellulose.

<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.

<Nylated cotton>
As the soluble nitrocellulose, soluble nitrocellulose that has been used in gravure printing ink compositions can be used. The soluble nitrocellulose is obtained by reacting natural cellulose with nitric acid to replace three hydroxyl groups in a six-membered ring of an anhydrous glucopyranose group in the natural cellulose with nitric acid groups to obtain a nitric acid ester. As the soluble nitrocellulose used in the present invention, one having a nitrogen content of 10 to 13% and an average degree of polymerization of 35 to 90 is preferably used. Specific examples include SS1/2, SS1/4, SS1/8, TR1/16, NCRS-2, (manufactured by KOREA CNC LTD), etc. The amount of soluble nitrocellulose 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 that have been 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, followed by hydrolysis. Generally, resins with 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 range of 0.1 to 3.0% by weight in the film gravure printing ink composition, 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 containing 2 to 30% by weight of acetylation, 17 to 53% by weight of butyrylation, and 1 to 5% by weight of hydroxyl groups 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 an amide group and a residue obtained by removing an acid group from a fatty acid. Examples of the fatty acid amide include monoamide, substituted amide, bisamide, methylol amide, and ester amide, and at least one selected from the group consisting of monoamide, substituted amide, and bisamide is preferable because it improves blocking resistance. The amount of the fatty acid amide used is preferably in the range of 0.01 to 1.0 mass% in the film gravure printing ink composition.

- 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, _R2 and _R3 represent a residue obtained by removing COOH from a fatty acid, and may be the same or different.)
Specific examples of the substituted amide include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide.

- 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 methylol amides include methylol palmitic acid amide, methylol stearic acid amide, methylol behenic acid amide, methylol hydroxystearic acid amide, methylol oleic acid amide, and methylol erucic acid amide.

Ester amide: Ester amide 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 ester amides include stearylamide ethyl stearate, oleylamide ethyl stearate, and the like.
The melting point of the fatty acid amide is preferably 50 to 150°C.
Moreover, the fatty acid constituting the fatty acid amide is preferably a saturated fatty acid having 12 to 22 carbon atoms and/or an unsaturated fatty acid having 16 to 25 carbon atoms, and more preferably a saturated fatty acid having 16 to 18 carbon atoms and/or an unsaturated fatty acid having 18 to 22 carbon atoms. 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 film gravure printing ink composition of the present invention preferably contains water in order to reduce printing defects caused by static electricity, prevent plate fogging, and improve cell reproducibility. The amount of water used in the film gravure printing ink composition is preferably 10% by mass or less, and more preferably in the range of 0.1 to 5.0% by mass.

<Other ingredients>
The film gravure printing ink composition of the present invention may further contain various additives such as a pigment dispersant, an antistatic agent, a plasticizer, etc.
A known method can be used to produce an ink composition using the above-mentioned constituent materials. Specifically, for example, the ink composition can be obtained by grinding a mixture of a pigment, a binder resin, an organic solvent, and, if necessary, a pigment dispersant, etc., using a high-speed mixer, a ball mill, a sand mill, an attritor, etc., and further adding and mixing the remaining materials such as a thiocyanate and predetermined additives.
Furthermore, a metal tetraalkoxide and/or a hydroxy acid may or may not be contained.

(Printing method using film gravure printing ink composition and laminate obtained thereby)
Next, a method for obtaining a laminate print using the ink composition of the present invention will be described.
The gravure printing ink composition for film of the present invention can also be used for applications other than lamination.
The method for obtaining a laminate print includes at least the following printing method. For example, a gravure printing ink composition for lamination is printed at least once on a resin film that is a known substrate for lamination by gravure printing. Next, another gravure laminate printing ink composition is printed by gravure printing at any position on the surface side of the gravure laminate printing ink layer formed by these printings (the lower layer side from the surface layer after final lamination), and then dried by a dryer.
A resin film or the like can be laminated by various methods on the layer side of the gravure laminate printing ink composition of the printed matter obtained by the above method to obtain a laminated printed matter for packaging bags, etc. Examples of the lamination method that can be used include an extrusion lamination method in which a molten polymer is laminated on the surface of the printed matter, with or without coating an anchor coating agent, and a dry lamination method in which an adhesive is applied to the surface of the printed matter, and then a film-like polymer is laminated.

The above-mentioned extrusion lamination method is a method in which a molten polymer is laminated on the surface of a printed material containing a layer of an ink composition by using a known extrusion laminating machine, after or without coating an anchor coating agent such as a titanium-based, urethane-based, imine-based or polybutadiene-based agent as necessary, and further, the molten resin can be laminated in a sandwich shape with other materials as an intermediate layer.
The molten polymer used in the extrusion lamination method may be any of the resins that have been used in the past, such as low-density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, etc. Among these, the effect of the present invention is enhanced when the composition is made with low-density polyethylene, which is prone to generate carbonyl groups due to oxidation during melting.
The dry lamination method is a method in which an adhesive such as a urethane adhesive or an isocyanate adhesive is applied to the surface of the layer of the ink composition for gravure laminate printing, and then a resin film is laminated using a known dry laminating machine. In particular, to obtain a packaging material for retort use, aluminum foil can be sandwiched between the substrate and the resin film to be laminated. Such a laminated product can be used for boiling and retort use after being made into a bag and filled with the contents.
Examples of the resin film used in this case include oriented and unoriented polyolefins such as polyethylene and polypropylene, polyester, nylon, cellophane, vinylon, etc. Furthermore, with regard to these resin films, films obtained by processing in advance such as coating or kneading an anti-fogging agent, or surface coating or kneading a matting agent can also be used.
Furthermore, as the resin film, films in which a barrier layer formed by depositing metal or coating a barrier resin on various printing plastic films can be used.

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

[Ink creation]
(Polyurethane resin varnish)
200 parts of 3-methyl-1,5-pentylene adipate diol having a number average molecular weight of 2,000 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 introduction tube. The reaction was carried out at 100 to 105° C. for 6 hours while introducing nitrogen gas. 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 various additives were added as shown in Table 1 below (% by mass in the ink composition) to obtain a white ink composition.

Alkylimidasoline compound A: mixture of 2-alkyl (C=8-18)-1-hydroxyethylimidazoline and 2-alkenyl (C=8-18)-1-hydroxyethylimidazoline (structure of formula (2) (Nonionic type) In both compounds, P is a 2-hydroxyethyl group)
Alkylimidasoline compound B: 2-propyl-2-imidazoline (manufactured by Tokyo Kasei Kogyo Co., Ltd.) Dispersant Alkylimidasoline compound C: Texnol (registered trademark) IL55 (manufactured by Nippon Nyukazai Co., Ltd., 1-hydroxyethyl-2-un Decylimidazoline)

<Printing>
100 parts by mass of each of the ink compositions of the 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 adjusted to 15 seconds using Zahn Cup No. 3 manufactured by Rigo Co., Ltd. Using a gravure printing machine, each of the diluted ink compositions was printed on the treated surface of each type of film under the following conditions, followed by drying to obtain printed matter.
For the evaluation of no white overprinting, each of the above white inks was printed on an OPP film. For the evaluation of white overprinting, "Bellcolor R Indigo 800" (manufactured by Sakata Inx Corporation) was used to print on an OPP film, and each of the above white inks was overprinted on top of the printing.
The specific evaluation method is shown below.

(Printing method and conditions)
Printing room environment: Temperature 25°C, humidity 50%
Coating machine: Gravure printing machine Coating speed: 150 m/min
Printing plate: Direct 175 lines 28 μm solid plate Drying temperature: 55°C
(Various films)
OPP: Corona discharge treated biaxially oriented polypropylene film

(Extrusion Laminate Strength)
Each printed matter of the Examples and Comparative Examples was treated with a polyethyleneimine anchor coating agent (EL-420, Toyo-Morton Co., Ltd.), and then molten polyethylene was laminated using an extrusion laminator to obtain a laminated product. These laminated products were cut to a width of 15 mm after aging at 40°C for 1 day, 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 1.
○: 100g/15mm or more △: 50g/15mm or more and less than 100g/15mm ×: Less than 50g/15mm

As described in each example, when an ink composition containing an alkylimidazoline compound and/or an alkenylimidazoline compound in a polyurethane resin was used, sufficiently high laminate strength could be obtained in the white overlapping area.
Among them, in Examples 1 to 3, all extrusion laminate strengths were high. According to Examples 4 and 5, in which an alkyl group having a smaller carbon number than the palmitole group in Example 1 was used, the extrusion laminate strength was slightly lower than in Example 1, but the alkylimidazoline compound and the alkenylimidazoline compound The laminate strength was higher than that of the comparative example containing neither of the following.

Claims (5)

A gravure printing oil-based ink composition for film containing a pigment, a polyurethane resin, and an organic solvent,
Containing an alkylimidazoline compound and/or an alkenylimidazoline compound in the solid content of the gravure printing oil-based ink composition for film ,
A gravure printing oil-based ink composition for films, which contains 10% by mass or less of water, or no water, based on the gravure printing oil-based ink composition for films. 2. The oil-based ink composition for gravure printing of film according to claim 1, wherein the alkyl imidazoline compound and/or the alkenyl imidazoline compound is a compound represented by the following formula (1) and/or formula (2) :

In formula (1) and formula (2), R is an alkyl group and/or an alkenyl group having 6 to 35 carbon atoms, P is a hydroxyalkyl group having 2 to 6 carbon atoms, and A is a halogen. The film gravure printing oil- based ink composition according to claim 1 or 2, wherein the alkyl imidazoline compound and/or the alkenyl imidazoline compound is contained in an amount of 0.2 to 7.0 mass % based on the solid content of the film gravure printing oil-based ink composition. 3. The oil-based ink composition for film gravure printing according to claim 1, wherein the polyurethane resin is a polyurethane resin that is not acid-modified. The gravure printing oil-based ink composition for film according to claim 1 or 2, wherein the pigment is a white inorganic pigment.