JP6492704B2 - Ink composition for metal sheet with polyester film - Google Patents

Description

  The present invention relates to a polyester film-laminated metal plate ink composition, and also relates to a laminate in which a polyester film coated with the ink and a metal plate for a metal can are bonded together with an adhesive.

  Metal cans have high oxygen barrier properties and light shielding properties, and are excellent in strength, so that they have been used as containers for various beverages and foods regardless of liquid or solid. Since metal cans have high oxygen barrier properties and light shielding properties, their contents are rarely altered even when compared with plastic bottles and the like. However, since the inside of the can cannot be confirmed from the outside, there is a problem that the contents cannot be understood as it is. Therefore, in order for food / beverage can manufacturers to differentiate their products by appearance, it is indispensable to add cosmetics to the can exterior.

  In recent years, beverage cans and food cans using a laminate in which a metal plate is bonded to a polyester film printed with an ink composition via an adhesive have been put into practical use. The can obtained by this method is also called a laminate can, and as the adhesive, for example, JP-A-11-301921, JP-A-08-34289, polyester-epoxy or polyester-polyisocyanate adhesive is used. ing. The laminate is baked at a high temperature of 200 ° C. or higher, and then molded and subjected to a retort process as a sterilization process.

  Various methods can be used as a method for printing the ink composition on a plastic film, and a gravure printing method can be used particularly for an ink composition for a metal sheet attached to a polyester film. The gravure printing method is capable of high-speed printing, high-definition printing with a large area, low cost, and high productivity.

  As the colorant contained in the ink composition, a colorant using aluminum particles or the like is often used so that excellent cosmetic properties can be obtained. However, the printing configuration used for laminate cans is often multi-layer overprinting, and when using an ink composition containing a pigment using aluminum particles, there is a problem in that poor imprinting (trapping failure) easily occurs during overprinting. is there.

  In addition, a laminated can obtained by using aluminum particles as a colorant, when subjected to retort treatment with hot water for sterilization after molding, can adhesive layer, printing ink printing layer, and plastic film There is a problem in that the adhesion between the layers tends to be lowered, and defective products cause delamination.

  In order to solve this problem, a method using aluminum particles surface-treated with an acrylic resin (Japanese Patent Laid-Open No. 2013-147615) or a method using aluminum particles surface-treated with a cellulose derivative (Japanese Patent Laid-Open No. 2003-342509) Has been proposed. However, aluminum particles that have been surface-treated with a resin undergo severe precipitation and hard cake formation in the ink composition over time, and are difficult to use after being redispersed. Furthermore, the glossiness and brightness feeling inherent in aluminum are reduced by the amount of resin coating, and cosmetics cannot be obtained.

  In addition, a method using a blocked isocyanate and a silane coupling agent has been proposed for an ink composition using ordinary aluminum particles (Japanese Patent No. 4193405). However, when a block isocyanate and a silane coupling agent are used in combination, the alcohol produced in the hydrolysis process of the silane coupling agent may react with the blocked isocyanate to lower the adhesiveness.

  That is, in a laminated can obtained using an ink composition having a pigment containing aluminum particles, when retorting with hot water for sterilization, the metal surface of the can, an adhesive layer, a printing layer of printing ink, And the fall of the adhesiveness between each layer of a plastic film has not led to a decisive solution.

Japanese Patent Application Laid-Open No. 11-301921 JP 08-34289 A JP2013-147615A JP 2003-342509 A Japanese Patent No. 4193405

  It is an object of the present invention to provide an ink composition for a polyester film-laminated metal plate that has good overprinting suitability in gravure printing or the like and has high adhesion even after hot water retort treatment.

  As a result of intensive studies on the above problems, the present inventor has found that the problem can be solved by using the following ink composition for a polyester film-laminated metal plate, and has led to the present invention.

That is, the present invention is an ink composition for a polyester film for laminating on a metal plate, which contains a pigment (A), a binder resin (B), an additive (C), and an organic solvent (D) , The present invention relates to an ink composition for a polyester film characterized by (1) and (2).
(1) The pigment (A) contains aluminum particles (a1) surface-treated with an unsaturated fatty acid. (2) The additive (C) contains silica particles (c1) having a silanol group and an average particle diameter of 1 μm to 5 μm and a silane coupling agent (c2).

In the present invention, the binder resin (B) includes the polyurethane resin (b1),
In addition, the present invention relates to the above-described ink composition for a polyester film , wherein the silane coupling agent (c2) contains a substituted or unsubstituted amino group-containing silane coupling agent (c2-1).

In the present invention, the polyurethane resin (b1) has at least one ethyleneimine group in the molecule,
And the substituted or unsubstituted amino group containing silane coupling agent (c2-1) contains the compound (c2-1-1) represented by the following general formula 1, The above polyester film ink Relates to the composition.
General formula 1


(In the formula, R ¹ represents a methoxy group or an ethoxy group, n represents an integer of 1 to 6, R ² and R ³ each independently represents a hydrogen atom or a substituted or unsubstituted phenyl group, Represents a substituted alkyl group.)

Moreover, this invention relates to the printed matter formed by printing the said ink composition for polyester films on a polyester film.

  Moreover, this invention relates to the laminated body formed by affixing with a metal plate on the printing surface of the said printed matter through an adhesive agent.

  Moreover, this invention relates to the metal cans which consist of the said laminated body.

  According to the present invention, a polyester that has good overprinting ability in gravure printing and the like, and does not decrease adhesiveness even after hot water retort treatment after molding a laminate formed by bonding with a metal plate for metal cans, etc. An ink composition for a film-laminated metal plate was obtained.

  Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention does not exceed the gist thereof. The content is not limited.

  A feature of the present invention is an ink composition for a metal sheet adhered to a polyester film containing a pigment (A), a binder resin (B), an additive (C), and an organic solvent (D), and the pigment (A) is not present. The aluminum particles (a1) surface-treated with saturated fatty acids are included, and the additive (C) further includes silica particles (c1) having an average particle diameter of 1 μm to 5 μm having silanol groups and a silane coupling agent (c2). It is.

  In this specification, the average particle diameter in the silica particles (c1) having an average particle diameter of 1 μm to 5 μm having a silanol group represents a particle diameter at an integrated value of 50% (D50) in the particle size distribution obtained by the Coulter counter method. The average particle size in the aluminum particles (a1) surface-treated with unsaturated fatty acids means the particle size at an integrated value of 50% (D50) in the particle size distribution determined by the laser diffraction / scattering method.

  The silane coupling agent (c2) hydrolyzes itself to form silanol groups, which have the property of dehydrating and condensing with hydroxyl groups on the surface of the inorganic material. In the present invention, by combining the silica particles (c1) having hydroxyl groups and silanol groups on the surface of the aluminum particles (a1), the dehydration condensation reaction of the silane coupling agent (c2) is not only between the aluminum particles (a1), There are a plurality of condensation reaction sites between the silica particles (c1) and between the aluminum particles (a1) and the silica particles (c1), thereby generating a strong cohesive force. For this reason, it has been found that strong adhesiveness is developed between a polyester film, an adhesive, and other ink layers.

  The pigment (A) in the present invention contains aluminum particles (a1) surface-treated with an unsaturated fatty acid. Corresponding particles are appropriately selected as the aluminum particles (a1) surface-treated with the unsaturated fatty acid, and those having a particle diameter of 5 to 20 μm are preferable from the viewpoint of brightness and hiding. From the viewpoint of handling and safety, the aluminum particles are preferably a mixture (paste) with an existing solvent. Aluminum particles treated with saturated fatty acids are referred to as leafing type, and the aluminum particles are oriented on the surface of the printing surface, so that they are set off during printing winding, which is not preferable from the viewpoint of blocking properties. Examples of the unsaturated fatty acid include fatty acids having an alkenyl group or alkynyl group having 10 to 24 carbon atoms. The unsaturated group contained in the alkenyl group or alkynyl group is preferably 1 to 3. Specific examples include oleic acid, linoleic acid, linolenic acid, and the like. The aluminum particles (a1) may be treated with a plurality of unsaturated fatty acids.

  Furthermore, the pigment (A) can be used in combination with organic and inorganic pigments used in general inks, paints, and recording agents. Examples of organic pigments that can be used in combination include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, isoindoline. And pigments of the type. Examples of indigo ink include copper phthalocyanine. More specifically, from the viewpoint of heat resistance, CI Pigment Yellow 180, CI Pigment Yellow 83, CI Pigment Yellow 139, CI Pigment Red 185, CI Pigment Red 122, CI Pigment Red 178, CI Pigment Red 149, CI Pigment Red 144, CI Pigment Red 166, CI Pigment Violet 23, CI Pigment Violet 37, CI Pigment Blue 15, CI Pigment Blue 15: 1, CI Pigment Blue 15: 2, CI Pigment Blue 15: 3, CI Pigment Blue 15: 4, CI Pigment Blue 15: 6, CI pigment green 7, CI pigment orange 34, CI pigment orange 64, carbon black and the like are more preferable.

  The pigment (A) is preferably contained in an amount sufficient to ensure the concentration and coloring power of the ink composition, that is, in a proportion of 1 to 50% by weight based on the total weight of the ink composition. In addition to the aluminum particles surface-treated with unsaturated fatty acid, the pigment (A) can be used in combination with one or more pigments.

  The binder resin (B) in the present invention may be any polymer material, such as polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, chlorinated polypropylene resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polyamide resin, Nitrocellulose resin, cellulose modified resin, acrylic resin, polyester resin, alkyd resin, polyvinyl chloride resin, rosin resin, rosin modified maleic resin, terpene resin, phenol modified terpene resin, ketone resin, cyclized rubber, chlorinated rubber, Examples include butyral, petroleum resin, and modified resins thereof. These resins can be used alone or in admixture of two or more, and the content thereof is preferably 5 to 25% by weight based on the total weight of the ink composition. Of these, the polyurethane resin (b1) is particularly preferred. When the binder resin (B) contains the polyurethane resin (b1), it forms a bond or hydrogen bond with the silanol group produced from the silane coupling agent, and has good adhesion to the polyester film, adhesive, or other ink layer. To express.

  The polyurethane resin (b1) is not particularly limited, and is appropriately produced by a known method. For example, a polyurethane resin (b1) obtained by reacting a urethane prepolymer of a terminal isocyanate composed of a polymer polyol (b1-1) and a polyisocyanate (b1-2) and an amine chain extender (b1-3). preferable.

  Examples of the polymer polyol (b1-1) include polyester polyols, polyether polyols, polycaprolactone diols, and polycarbonate polyols. Among them, the polyester polyol (b1-1-1) is a polymer polyol (b1-1). ) A compound containing 50% by weight or more in 100% by weight is preferable, and other dimer diols, hydrogenated dimer diols, castor oil-modified polyols and the like may be used in combination.

  Examples of the polyester polyol (b1-1-1) include adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, pimelic acid, azelaic acid, sebacin. Dibasic acids such as acid, suberic acid, glutaric acid, 1,4-cyclohexyl dicarboxylic acid, dimer acid and hydrogenated dimer acid, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1 , 4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2- Methyl-1,3-propanediol, 3,3,5-trimethylpe Nthanediol, 2,4-diethyl-1,5-pentanediol, 1,12-octadecanediol, 1,2-alkanediol, 1,3-alkanediol, 1-monoglyceride, 2-monoglyceride, 1-monoglycerin ether And condensates obtained by esterification reaction with diols such as 2-monoglyceryl ether, dimer diol, hydrogenated dimer diol, etc. In particular, when used as a binder resin, diol having adipic acid and a branched structure Polyester polyol composed of (neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, etc.) has good pigment dispersion stability, retort resistance, blocking resistance, and printability. It is particularly preferable in terms of improvement. These polyester polyols (b1-1-1) can be used alone or in admixture of two or more. Furthermore, a polyol having 3 or more hydroxyl groups and a polyvalent carboxylic acid having 3 or more carboxyl groups can be used in combination.

The number average molecular weight of the polyester polyol (b1-1-1) used in the present invention is appropriately determined in consideration of the solubility, drying property, blocking resistance and the like of the resulting polyurethane, and is usually 500 to 100,000. Preferably it is in the range of 1000 to 5,000. If the number average molecular weight is less than 500, the printability tends to be inferior due to a decrease in solubility due to an increase in the amount of hard segments. On the other hand, if the number average molecular weight exceeds 100,000, the proportion of hard segments decreases and the drying property is decreased. And there exists a tendency for blocking resistance to fall. In addition, the number average molecular weight of the polyol used in the present invention is calculated from the hydroxyl value with the terminal as a hydroxyl group, and is obtained from (Equation 1).

(Formula 1) Number average molecular weight of polyol = 1000 × 56.1 × hydroxyl number of hydroxyl group / hydroxyl value

The acid value of the polyester polyol (b1-1-1) used in the present invention is preferably 1.0 mgKOH / g or less, and more preferably 0.5 mgKOH / g or less. This is because when the acid value is larger than 1.0 mgKOH / g, the tendency of the varnish of the polyurethane resin (b1) and the printing ink to thicken with time increases.

  The polymer polyol (b1-1) may contain a polyether polyol (b1-1-2). Examples thereof include polyether polyols of polymers or copolymers such as ethylene oxide, propylene oxide, and tetrahydrofuran. In particular, polytetramethylene glycol and polypropylene glycol have excellent solubility in alcohol solvents, and therefore can impart another solvent solubility to polyester polyurethane. The polyether polyol (b1-1-2) preferably has a number molecular weight of 700 to 3000 in order to develop these characteristics and not lower the water resistance. Among these, from the viewpoint of stability at low temperature, it is preferable to use polypropylene glycol made of propylene oxide. However, since polypropylene glycol has low affinity with the polyester film, the polyether polyol (b1-1-2) in 100% by weight of the polymer polyol (b1-1) is 50% by weight from the viewpoint of adhesion to the polyester film. % Or less is desirable.

  As polyisocyanate (b1-2) used for this invention, various well-known aromatic diisocyanate, aliphatic diisocyanate, alicyclic diisocyanate, etc. which are generally used for manufacture of a polyurethane resin are mentioned. For example, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1 , 3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, Cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate , Dimeryl diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tri Examples thereof include diisocyanate, dimerisocyanate obtained by converting a diisocyanate carboxyl group into diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, and a dimer acid carboxyl group. These diisocyanate compounds can be used alone or in admixture of two or more.

  The polyurethane resin (b1) more preferably has an ethyleneimine group in the molecule. Here, the ethyleneimine group is a monovalent substituent obtained by removing one hydrogen atom from aziridine. In many cases, the printing surface of the polyester film is subjected to corona discharge treatment, and a functional group such as a carboxylic acid group is present on the film surface. The ethyleneimine group reacts with this carboxylic acid group, dramatically improving the adhesion to the film, and suppressing delamination after retorting in the laminate bonded to the metal plate.

  The ethyleneimine group in the polyurethane resin may be introduced into any part of the polyurethane resin, for example, may be introduced into the terminal, or may be introduced into the main chain or the side chain.

  As a method for introducing an ethyleneimine group into a polyurethane resin, for example, a compound having a hydroxyl group and an ethyleneimine group and another diol are mixed, an isocyanate group-containing urethane prepolymer is obtained by a diisocyanate compound, and then another diamine compound is obtained. For example, by introducing a chain extension reaction with an isocyanate group-containing prepolymer. In this case, when a compound having an ethyleneimine group and one hydroxyl group is used, the ethyleneimine group is introduced at the resin end, and when a compound having an ethyleneimine group and a plurality of hydroxyl groups is used, it is introduced into the main chain skeleton. The

  Specific examples of the compound having an ethyleneimine group and one hydroxyl group include 1- (2-hydroxyethyl) ethyleneimine, bis (1-aziridinpropanoic acid) 2-[[3- (1-aziridinyl) -1-oxo Propoxy] methyl] -2- (hydroxymethyl) -1,3-propanediyl, 1-phenyl-2-aziridinylethanol and the like. Specific examples of the compound having an ethyleneimine group and a plurality of hydroxyl groups include trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, and the like.

The amount of the ethyleneimine group is 0.1 × 10 ⁻³ to 10 × 10 5 of the ethyleneimine group represented by the general formula (1) per 1 g of resin solid content obtained by mixing the polyurethane resin (a) and the polyurethane resin (b). -A range of ³ gram equivalents is preferred. When it is less than 0.1 × 10 ⁻³ gram equivalent, the water resistance of the printed matter, that is, the retort resistance is inferior. If it exceeds 10 × 10 ⁻³ gram equivalent, the stability over time of the ink composition becomes poor.

  In the present invention, a urea bond can be introduced into the polyurethane resin using a known chain extender. Examples of the amine chain extender (b1-3) include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypyrroleethylenediamine, di-2-hydroxy Amines having a hydroxyl group in the molecule such as pyrrolpyethylenediamine and di-2-hydroxypropylethylenediamine can also be used. These chain extenders can be used alone or in admixture of two or more. If necessary, polyfunctional amine chain extenders can also be used. Specifically, diethylenetriamine, iminobispropylamine: (IBPA, 3,3′-diaminodipropylamine), N- (3-aminopropyl) ) Butane-1,4-diamine: (spermidine), 6,6-iminodihexylamine, 3,7-diazanonan-1,9-diamine, N, N′-bis (3-aminopropyl) ethylenediamine.

  Moreover, a monovalent active hydrogen compound can also be used as a polymerization terminator for the purpose of terminating excess reaction. Examples of such compounds include compounds having primary and secondary amino groups, dialkylamines such as di-n-butylamine, amino alcohols, and the like. Furthermore, amino acids such as glycine and L-alanine can be used as a reaction terminator, particularly when it is desired to introduce a carboxyl group into the polyurethane resin. Among these, amino alcohols having primary and secondary amino groups need to be controlled so as to react only with amino groups while avoiding reaction at high temperature when used as a terminal terminator. These end terminators can be used alone or in admixture of two or more.

  The polyurethane resin (b1) is synthesized by reacting the polymer polyol (b1-1) with the polyisocyanate (b1-2) and then an amine chain extender (b1-3) and, if necessary, a polymerization terminator. It is preferable to react to make a polyurethane resin. For the polyurethane resin (b1), a polymer polyol (b1-1) and a polyisocyanate (b1-2) are optionally used in an inert solvent for an isocyanate group, and if necessary, a urethanization catalyst is used. And reacting at a temperature of 10 to 150 ° C. (urethanization reaction) to produce a prepolymer having an isocyanate group at the terminal, and then reacting this prepolymer with an amine chain extender (b1-3) to form a polyurethane resin The prepolymer method for obtaining (b1), or the polymer polyol (b1-1), the polyisocyanate (b1-2), the amine chain extender (b1-3) and (and the polymerization terminator) are reacted in one step. Thus, the polyurethane resin (b1) can be produced by a known method such as a one-shot method. The amine chain extender (b1-3) can also be used in the urethanization reaction with the polyisocyanate (b1-2) together with the polymer polyol (b1-1).

  In producing the prepolymer, the amount of the polymer polyol (b1-1) and the polyisocyanate (b1-2) depends on the number of moles of isocyanate groups of the polyisocyanate (b1-2) and the polymer polyol (b1-1). It is preferable that the NCO / OH ratio, which is the ratio of the number of moles of the total hydroxyl groups, be in the range of 1.1 to 3.0. If this ratio is less than 1.1, the molecular weight of the prepolymer will be excessively extended, making it impossible to carry out chain extension reaction. If it is more than 3.0, urea bonds will be excessive, and the solubility of the resulting prepolymer will be low. A tendency to decrease is observed.

  Moreover, it is preferable from the surface of reaction control to use a solvent for reaction. Examples of solvents that can be used include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethers such as dioxane and tetrahydrofuran; aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; Examples include halogenated hydrocarbons such as chlorobenzene and parklene. These may be used alone or in combination as a mixed solvent.

  Furthermore, a catalyst can also be used for this urethanation reaction. Examples of catalysts that can be used include tertiary amine catalysts such as triethylamine and dimethylaniline; metal catalysts such as tin and zinc. These catalysts are usually used in the range of 0.001 to 1 mol% with respect to the polyol compound.

  The above-obtained prepolymer having an isocyanate group at the terminal and the amine chain extender (b1-3) diamine, triamine and the like are reacted at 10 to 80 ° C., and a high molecular weight containing an active hydrogen group at the terminal The polyurethane resin (b1) is obtained.

  When using a polymerization terminator, the chain terminator and chain extender may be used together to carry out the chain extension reaction, and after the chain extension reaction has been performed to some extent with the chain extender, the end terminator is added alone. Thus, an end termination reaction may be performed. On the other hand, the molecular weight can be controlled without using a terminal terminator, but in this case, a method of adding a prepolymer to a solution containing a chain extender is preferable in terms of reaction control.

  The ratio of the total number of moles of the amino group of the amine chain extender (b1-3) to the equivalent of the isocyanate group in the prepolymer is in the range of 1.01 to 2.00, preferably 1.03 to 1.06. To react. When this ratio is large and the amount of amine chain extender (b1-3) used is large, these tend to remain unreacted and odor tends to remain. When this ratio is small, the molecular weight is low. It stretches too much and gels.

  The polyurethane resin (b1) preferably has a weight average molecular weight of 10,000 to 100,000. If it is smaller than 10,000, it is difficult to ensure blocking resistance and solvent resistance in the printed matter, and if it is larger than 100,000, it is difficult to ensure printability because the solubility in the solvent in the present invention is poor.

  The polyurethane resin (b1) preferably has an amine value of 1.0 to 20.0 mgKOH / g. If the amine value is lower than 1.0, it is difficult to ensure adhesion to the polyester film, and if it is greater than 20.0, it is difficult to ensure ink stability when an isocyanate curing agent is added.

  The additive (C) in the present invention contains silica particles (c1) having an average particle diameter of 1 μm to 5 μm and a silane coupling agent (c2) having silanol groups.

  The silica particle (c1) having a silanol group has both a function of a crosslinking reaction with the silane coupling agent (c2) and a function of improving the printability of overprinting. Although the crosslinking reaction is as described above, in the overprinting, the silica particles (c1) have a function of lowering the surface tension by roughening the printing surface, so that wetting spread (leveling property) of the overlapping ink is improved. Beautifully overprinted. The average particle diameter may be in the range of 1 μm to 5 μm, and if it is larger than 5 μm, precipitation is promoted, and if it is smaller than 1 μm, the effect of improving the leveling property is not exhibited. The addition amount is preferably 0.1% by weight to 2.0% by weight, more preferably 0.3% by weight to 1.0% by weight, with respect to 100% by weight of the ink composition.

In view of the reactivity with organic materials and the strength of interaction, the silane coupling agent (c2) preferably contains a substituted or unsubstituted amino group (silane coupling agent (c2-1)). It may be a dimer. Among the silane coupling agents (c2-1) containing a substituted or unsubstituted amino group, those having a structure represented by the following general formula (1) (c2-1-1) are preferable.



General formula (1)



(Wherein R ¹ represents a methoxy group or an ethoxy group, n represents 1 to 6, R ² and R ³ represent a hydrogen atom, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted alkyl group. )

R ^{1 in the} general formula (1) is hydrolyzed to form a silanol group. The silanol group is dehydrated and condensed with the hydroxyl group of the surface of the inorganic material (that is, silica particles (c1) or aluminum particles (a1) having a silanol group) and the organic material, and the substituted or unsubstituted amino group is a polyester. Responsible for bonding or hydrogen bonding with the film, adhesive and binder resin (A). Therefore, one of R ² and R ³ in the general formula (1) is preferably a hydrogen atom, and the other is preferably a substituted or unsubstituted phenyl group or an alkyl group. The silane coupling agent is used in a mixture of 0.01 wt% to 10.0 wt%, preferably 0.1 wt% to 5.0 wt% with respect to 100 wt% of the ink composition. If it is added in a larger amount, by-product methanol or ethanol will reversely inhibit the curing reaction, and if the amount is less than this, a sufficient curing reaction may not be obtained.

  Specific examples of the substituted or unsubstituted phenyl group in the present invention include, for example, a phenyl group, a biphenylenyl group, a triphenylenyl group, an o-, m- and p-aminophenyl group, a 4-methylthiophenyl group, 3,5- Dicyanophenyl group, o-, m- and p-tolyl group, xylyl group and the like can be mentioned.

  In the present invention, the substituted or unsubstituted alkyl group includes a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a 2-ethylhexyl group, a heptyl group, and an octyl group. , Isooctyl group, stearyl group, aminoethyl group, aminopropyl group and the like.

  The additive (C) can contain other known ones as appropriate. In the production of the ink composition, known additives such as pigment derivatives, dispersants, wetting agents, adhesion aids, and leveling agents are used as necessary. Antifoaming agents, antistatic agents, trapping agents, antiblocking agents, wax components and the like can be used.

  Examples of the organic solvent (D) used in the ink composition of the present invention include aromatic organic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate, n-propyl acetate, isopropyl acetate, and isobutyl acetate. , Ester solvents such as propylene glycol monoethyl ether acetate and propylene glycol monomethyl ether acetate, alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, propylene glycol monoethyl ether, propylene glycol monomethyl ether, etc. Can be used.

  As the hue in the ink composition of the present invention, only aluminum particles (a1) and silica particles (c1) may be used. If necessary, the ink composition of other hues (in addition to white as a process basic color) , Yellow, red, indigo, and ink, 5 colors in total, red (orange), grass (green), and purple as process gamut colors, and transparent yellow, peony, vermilion, brown, and pearl) You may do it.

  The pigment (A) is preferably contained in an amount sufficient to ensure the concentration and coloring power of the ink composition, that is, in a proportion of 1.0 to 40.0% by weight based on the total weight of the ink composition. . These pigments can be used alone or in combination of two or more. When the aluminum particles (a1) surface-treated with unsaturated fatty acids are used alone, the amount added is preferably 1.0% to 25.0% by weight, more preferably 100.0% by weight, more preferably 10% by weight. 5.0 wt% to 15.0 wt%. If it is more than this range, the cohesive force will be insufficient, so delamination will occur during retort processing, and if it is less, the desired brightness will not be obtained. Further, when the other pigment and aluminum particles (a1) surface-treated with unsaturated fatty acid are used in combination, the total amount of the pigment is 1.0 wt% to 40.0 wt%, more preferably 5.0 wt% to 20 wt%. The weight ratio of the aluminum particles (a1) to the pigment is appropriately selected from 1:99 to 99: 1, preferably 30:70 to 70:30.

  In order to stably disperse the pigment (A) in the organic solvent, the resin can be dispersed alone, but a dispersant can also be used in combination in order to disperse the pigment stably. As the dispersant, anionic, nonionic, cationic, amphoteric surfactants can be used. The dispersant is preferably contained in the ink in an amount of 0.05% by weight or more based on the total weight of the ink from the viewpoint of the storage stability of the ink and 10% by weight or less from the viewpoint of the suitability for lamination. Furthermore, it is more preferable that it is contained in the range of 0.1 to 3% by weight.

  The ink composition of the present invention can be produced by dissolving and / or dispersing the polyurethane resin (b1), the pigment (A) and the like in an organic solvent. Specifically, a pigment dispersion in which a pigment is dispersed in an organic solvent with the polyurethane resin (b1) and the dispersant is produced, and the obtained pigment dispersion is further added to the polyurethane resin (b1), or if necessary. Ink compositions can be produced by blending other compounds.

  Since the aluminum particles (a2) are plate-like particles, the structure of the strong disperser (roller mill, ball mill, pebble mill, attritor, sand mill, etc.) may change and the brightness and concealment may be reduced. Therefore, it is preferable to disperse with a disperser or the like while gradually adding to a transparent medium or other color ink mixture.

  Regarding the method for producing the ink composition of the present invention, the particle size distribution of the pigment dispersion composed of the pigment, the binder resin and the organic solvent is the size of the grinding media of the disperser, the filling rate of the grinding media, the dispersion treatment time, It can be adjusted by appropriately adjusting the discharge speed, the viscosity of the pigment dispersion, and the like. As the disperser, generally used, for example, a roller mill, a ball mill, a pebble mill, an attritor, a sand mill and the like can be used.

  In the case where bubbles or unexpectedly large particles are included in the ink, it is preferably removed by filtration or the like in order to reduce the quality of the printed matter. A conventionally well-known filter can be used.

  The viscosity of the ink composition produced by the above method is such that the viscosity at Zahn cup # 4 is about 10 to 30 seconds from the viewpoint of preventing the pigment from settling and dispersing appropriately, and from the viewpoint of workability efficiency during ink production and printing Is preferably in the range of 12 to 22 seconds.

  The viscosity of the ink composition can be adjusted by appropriately selecting the type and amount of raw materials used, for example, resin, pigment, organic solvent and the like. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

  The ink composition of the present invention can be used in known printing methods such as gravure printing and flexographic printing. For example, it is diluted with a diluent solvent to a viscosity and concentration suitable for gravure printing, and is supplied to each printing unit alone or mixed.

  Next, a laminate obtained by bonding a printed material using the ink composition of the present invention to a metal plate via an adhesive will be described. In the laminate of the present invention, the film to be bonded to the metal plate may be a polyester film, but it is preferable that 75 to 100% by weight of the ester repeating unit is composed of an ethylene terephthalate unit. Examples of the ester unit other than the ethylene terephthalate unit include ester units such as phthalic acid, isophthalic acid, succinic acid, and adipic acid. The polyester film preferably has a surface subjected to surface treatment such as corona discharge treatment in order to improve adhesion to the ink of the present invention and further to the adhesive.

  As the metal plate used in the present invention, hot rolled steel sheet, cold rolled steel sheet; hot dip galvanized steel sheet, electrogalvanized steel sheet, iron-zinc alloy plated steel sheet, zinc-aluminum alloy plated steel sheet, nickel-zinc alloy plated steel sheet, Various plated steel plates such as nickel-tin alloy plated steel plate, tinplate, chrome plated steel plate, aluminum plated steel plate, turn plated steel plate, nickel plated steel plate; metal materials such as stainless steel, tin-free steel, aluminum plate, copper plate, titanium plate, and If necessary, those metal materials subjected to chemical conversion treatment, for example, phosphate treatment, chromate treatment, composite oxide film treatment, etc. can be used.

  As an adhesive used for the production of the laminate in the present invention, a one-part curable or two-cured liquid type polyacrylic resin adhesive, a polyester resin adhesive, a polyurethane resin adhesive, an epoxy resin adhesive, Examples thereof include a blocked isocyanato adhesive and a combination adhesive thereof. Although there is no limitation in particular as a kind of hardening reaction, since the lamination can has a baking process, the thing by a thermosetting reaction is preferable. Further, a curing reaction by an electron beam or UV light may be used as an auxiliary.

  The laminated body formed by laminating the printed sheet obtained by printing the polyester film-laminated metal sheet ink composition in the present invention with the metal sheet via an adhesive can be produced, for example, by the following method. First, the ink composition of the present invention is applied to a corona discharge treatment surface of a polyester film having a thickness of about 5 to 30 μm by a gravure printing method so as to have a dry film thickness of about 0.3 to 3 μm. And dried at a temperature of 40 to 80 ° C. until tack-free. Next, an adhesive is applied to the printing surface of the polyester film on which the ink layer obtained as described above is formed by a known coating means such as spray coating, roll coating, gravure coating, etc., and the temperature is 150 to 200 ° C. Dry with. A polyester film having a gravure ink layer and an adhesive layer obtained as described above is bonded to a metal plate, and heated and laminated at a temperature of about 150 ° C. to 250 ° C. for a short time (usually about 2 seconds or less). Can be manufactured.

  The laminate formed by printing the ink composition for a polyester film affixed metal plate in the present invention on a metal plate via an adhesive is used for cans such as beverage cans, food cans, miscellaneous cans, and 5 gallon cans. Suitable for metal lids such as caps and caps. Furthermore, the present invention can be applied to the outer surface of household equipment such as a magic bottle and the outer surface of a refrigerator.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples. In the present invention, parts and% represent parts by weight and% by weight unless otherwise noted.

The hydroxyl value is calculated by converting the amount of hydroxyl group in 1 g of resin calculated by esterifying or acetylating the hydroxyl group in the resin with excess acid anhydride and back titrating the remaining acid with alkali to the number of mg of potassium hydroxide. The value obtained in accordance with JIS K0070. The amine value is the number of mg of potassium hydroxide equivalent to the equivalent amount of hydrochloric acid required to neutralize the amino group contained in 1 g of resin. The acid value is the number of mg of potassium hydroxide required to neutralize the acid group contained in 1 g of resin, and the measurement method may be a known method, generally according to JIS K0070 (1996). Done. The method for measuring the amine value was as described below. The molecular weight (weight average molecular weight) of the polyurethane resin was determined as a polystyrene-converted molecular weight by measuring the molecular weight distribution using a GPC (gel permeation chromatography) apparatus. The method for measuring the amine value is as follows.
[Method for measuring amine value]
Weigh 0.5-2 g of sample accurately. (Sample amount: Sg) 30 mL of neutral ethanol (BDG neutral) is added to a precisely weighed sample and dissolved. The obtained solution is titrated with a 0.2 mol / l ethanolic hydrochloric acid solution (titer: f). The point at which the color of the solution changed from green to yellow was taken as the end point, and the amine value was determined by the following (Formula 1) using the titration amount (AmL) at this time.
(Formula 1) Amine number = (A × f × 0.2 × 56.108) / S

  In addition, the silver ink in this example shows the glossiness (luminance feeling) of aluminum particles as silver, and the gold ink means the glossiness (luminance feeling) of transparent yellow pigment (CI Pigment Yellow 83) and aluminum particles. Indicates gold color.

(Synthesis Example 1)
200 parts of a polyester diol having a number average molecular weight of 2000 (hereinafter “PMPA2000”) obtained from adipic acid and 3-methyl-1,5-pentadiol, 46.7 parts of isophorone diisocyanate (hereinafter “IPDI”) and 61.7 parts of toluene. Was reacted at 80 ° C. for 4 hours under a nitrogen stream to obtain 308 parts of a solvent solution of a terminal isocyanate prepolymer. Next, 20.2 parts of isophoronediamine (hereinafter “IPDA”), 1.0 part of di-n-butylamine (hereinafter “DBA”), 280.5 parts of toluene and 280.5 parts of methyl ethyl ketone (hereinafter “MEK”) were mixed. The resulting terminal isocyanate prepolymer solution was gradually added to the product at room temperature, and then reacted at 50 ° C. for 1 hour to give a polyurethane having a solid content of 30%, an amine value of 6.1 mgKOH / g, and a weight average molecular weight of 35,000. A resin solution PU1 was obtained.

(Synthesis Examples 2-9)
Polyester diols (“PMPA1000”, “PMPA2000”, “PMPA5000”) having number average molecular weights of 1000, 2000, and 5000 obtained from adipic acid and 3-methyl-1,5-pentadiol are prepared, and the raw materials shown in Table 1 are used. By the same method as in Synthesis Example 1, polyurethane resin solutions PU2 to PU9 were obtained. In Table 1, “PPA” is a polyester diol obtained from adipic acid and 1,2-propanediol, “PCL” is a polycaprolactone diol obtained by ring-opening polymerization of ε-caprolactone, and “PC” is a polycarbonate. The diol, “PPG” refers to polypropylene glycol. “TZ” represents bis (1-aziridinepropanoic acid) 2-[[3- (1-aziridinyl) -1-oxopropoxy] methyl] -2- (hydroxymethyl) -1,3-propanediyl; “IPA” represents isopropanol. Further, the number average molecular weight of the polyol used in the present invention was calculated by assuming that the polymer was all diol molecules from the hydroxyl value.
In Synthesis Examples 3, 5, 6, 8, and 9, TZ is used and reacted with a polyol and an isocyanate in a urethane prepolymer synthesis stage.

(Production Example 1: Preparation of silver ink composition)
15 parts of oleic acid-treated aluminum paste TD280 (manufactured by Toyo Aluminum Co., Ltd.), 1.0 part of silica particles having a silanol group (2.0 μm: manufactured by Mizusawa Chemical Co., Ltd.), silane coupling agent (trimethoxy [3- (phenylamino) ) Propyl] silane: manufactured by Tokyo Chemical Industry Co., Ltd.) 3.0 parts, 60 parts of polyurethane resin PU1, and 21 parts of a MEK (methyl ethyl ketone) / toluene mixed solution were stirred with a disper (500 rpm) for 10 minutes. A silver ink composition R1 for metal plates was obtained.

(Production Examples 2 to 16: Preparation of silver ink composition)
Using the pigments shown in Table 2-1, the polyurethane resin (PU) in Table 1 and the resins and additives shown in Table 2-1, they were mixed in the same manner as in Production Example 1, and the silver ink composition R2 for metal plates ~ R16 was obtained.
Silica particles having particle sizes of 2.0 μm and 3.0 μm (Mizusawa Chemical Co., Ltd.) and 0.5 μm (Core Front Co., Ltd.) were used.
Examples of the silane coupling agent include trimethoxy [3- (phenylamino) propyl] silane, 3-aminopropyltrimethoxysilane, trimethoxy [3- (methylamino) propyl] silane, and 3- (2-aminoethylamino). Propyltrimethoxysilane and dodecyltriethoxysilane were used (both manufactured by Tokyo Chemical Industry Co., Ltd.). Trimethoxy [3- (phenylamino) propyl] silane, 3-aminopropyltrimethoxysilane, trimethoxy [3- (methylamino) propyl] silane, 3- (2-aminoethylamino) propyltrimethoxysilane has an amino group. Corresponding to the contained silane coupling agent (c2-1), trimethoxy [3- (phenylamino) propyl] silane, 3-aminopropyltrimethoxysilane, and trimethoxy [3- (methylamino) propyl] silane are generally It corresponds to the silane coupling agent (c2-1-1) represented by the formula (1).
Also, as the vinyl chloride-vinyl acetate copolymer resin (vinyl chloride-vinyl acetate polymer), Solvein M5 (solid content 25%) manufactured by Nisshin Chemical Co., Ltd. was used.

(Production Example 17: Preparation of transparent yellow ink composition)
40 parts of polyurethane resin PU1, C.I. I. 7 parts of Pigment Yellow 83 and 10 parts of MEK / toluene mixed solution were mixed and kneaded with a paint shaker for 1 hour, and then 43 parts of MEK / toluene mixed solution were added and mixed to obtain a transparent yellow ink composition S1. .

(Production Example 18: Preparation of silver ink composition)
A mixture of 15 parts of oleic acid-treated aluminum paste TD280 (manufactured by Toyo Aluminum Co., Ltd.), 60 parts of polyurethane resin PU3, and 25 parts of a MEK (methyl ethyl ketone) / toluene mixed solution was stirred with a disper (500 rpm) for 10 minutes. A silver ink composition T1 for metal plates was obtained.

(Production Examples 19 to 33: Preparation of silver ink composition)
Using the pigments shown in Table 2-2, the polyurethane resin (PU) in Table 1 and the resins and additives listed in Table 2-2, they were mixed in the same manner as in Production Example 18, and the silver ink composition T2 for metal plates ~ T16 was obtained.
As silica particles, particles having a particle size of 0.5 μm (manufactured by Corefront Corporation), 2.0 μm (manufactured by Mizusawa Chemical Industry Co., Ltd.) and 8.5 μm (manufactured by Mizusawa Chemical Industry Co., Ltd.) were used.
As the silane coupling agent, trimethoxy [3- (phenylamino) propyl] silane, 3- (2-aminoethylamino) propyltrimethoxysilane, and dodecyltriethoxysilane were used (all manufactured by Tokyo Chemical Industry Co., Ltd.). .
Also, as the vinyl chloride-vinyl acetate copolymer resin (vinyl chloride-vinyl acetate polymer), Solvein M5 (solid content 25%) manufactured by Nisshin Chemical Co., Ltd. was used.
In Production Examples 19, 23 and 25, Sumidur BL3175 (manufactured by Sumika Bayer) was used as the hexamethylene diisocyanate block isocyanate.

(Production Examples 34 to 49: Preparation of gold ink composition)
50 parts of silver ink compositions R1 to R16 for metal plates and 50 parts of transparent yellow ink composition S1 were mixed with a disper to obtain gold ink compositions U1 to U16 for metal plates.

(Production Examples 50 to 64: Preparation of gold ink composition)
50 parts of silver ink compositions T1 to T16 for metal plates and 50 parts of transparent yellow ink composition S1 were mixed with a disper to obtain gold ink compositions V1 to V16 for metal plates.

Example 1
<Silver overprint>
The silver ink composition R1 is diluted with a mixed solvent (toluene: MEK: IPA = 40: 50: 10) so that the viscosity becomes 17 seconds (25 ° C., Zahn cup No. 3), and the laser plate depth Two layers at a printing speed of 150 m / min on a corona discharge treated surface of a 12 μm thick corona discharge-treated polyethylene terectrate film “E5100” (manufactured by Toyobo Co., Ltd.) using a gravure printing machine equipped with a gradation plate of 35 μm to 5 μm Overprinting was performed to obtain a printed material W1.
<Gold / silver overprint>
Using the gold ink composition U1 and the silver ink composition R1, a mixed solvent (toluene: MEK: IPA = 40: 50: 10) is used so that the viscosity becomes 17 seconds (25 ° C., Zaan cup No. 3). Printing speed on the corona discharge treated surface of a 12μm thick corona discharge-treated polyethylene terectrate film “E5100” (manufactured by Toyobo Co., Ltd.) using a gravure printing machine diluted and equipped with a gradation plate having a laser plate depth of 35 μm to 5 μm The gold ink composition and the silver ink composition were overprinted at 150 m / min to obtain a printed material X1.

(Examples 2-16, Comparative Examples 1-16)
<Silver overprint>
In the same manner as in Example 1, using the silver ink compositions R2 to R16 and T1 to T16 described in Table 3-1 and Table 3-2, printed materials W2 to W16 (Examples) and Y1 to Y16 (Comparison) Example) was obtained.
<Gold / silver overprint>
In the same manner as in Example 1, using the gold ink compositions U2 to U16, V1 to V16 and the silver ink compositions R2 to R16 and T1 to T16 described in Table 3-1 and Table 3-2, a printed matter X2 -X16 (Example) and Z1-Z16 (comparative example) were obtained.

  The printed materials W1 to W16 (Examples) and Y1 to Y16 (Comparative Examples), X2 to X16 (Examples) and Z1 to Z16 (Comparative Examples) obtained in Examples 1 to 16 and Comparative Examples 1 to 16 are aluminum. Tests for pigment redispersibility, brightness, tape adhesion, blocking resistance, retort resistance, and trapping properties were performed.

<Aluminum pigment redispersibility>
The ink compositions R1 to R16 and T1 to T16 were stored at 25 ° C. for 7 days, and the ease of redispersion when the precipitated aluminum paste was redispersed with a disper was evaluated.
○ ····· Re-dispersion in 1 minute.
○ △ ・ ・ ・ ・ ・ Can be redispersed in 5 minutes.
△ ・ ・ ・ ・ ・ ・ Redispersion takes 10 minutes or more.
Δ × ・ ・ ・ ・ ・ Re-dispersion is possible, but partial re-dispersion is not possible.
× ···· Redispersion is difficult.
○ and ○ △ are ranges where there is no practical problem.

<Luminance>
Metal gloss was evaluated by evaluating 35 μm overlaps of the printed products W1 to W16 and Y1 to Y16 of the corona-treated PET film with a small gloss meter microtrigloss (reflection angle 60 °).
If the luminance is a gloss value of 100 or more, there is no practical problem.
<Tape adhesiveness>
Printed film when the printed matter W1-W16 and Y1-Y16 of the corona-treated PET film are peeled immediately in 90 ° direction after applying a cellophane tape on the printed surface and pressing it strongly with a roller 5 times immediately after printing. The appearance state of was visually determined. The determination criteria were as follows.
○ ・ ・ ・ No peeling at all.
○ Δ: 80% or more of the printed film remained on the film.
Δ: 50 to 80% of the printed film remained on the film.
Δ ×: 50% or less of the printed film remained on the film.
× ··· All peeled off.
○ and ○ △ are ranges where there is no practical problem.

<Blocking resistance>
Using the 35 μm overlapped portion of the printed matter W1 to W16 and Y1 to Y16, the film is overlapped so that the printed surface and the non-printed surface of the corona-treated PET printed matter are in contact with each other, and a load of 10 kgf / cm ² is applied. The ink was allowed to stand in an 80% RH environment for 24 hours, and after removal, the state of ink transfer to the non-printed surface was evaluated in five stages.
○: 0% transfer of ink to non-printing surface.
○ △: Less than 10% of ink transferred to non-printing surface.
Δ: Transfer amount is 10% or more and less than 30%.
Δ ×: Transfer amount is 30% or more.
× ··· Close contact.
○ and ○ △ are ranges where there is no practical problem.

<Retort resistance>
A thermosetting epoxy resin adhesive was applied to the printed surfaces of the printed materials W1 to W16 and Y1 to Y16 so that the dry coating weight was 5.5 g / m ² and preliminarily dried at 180 ° C. Next, a tin-free steel plate is used as the metal plate for the can, and the printed film provided with the adhesive layer and the metal plate for the can are overlaid so that the adhesive layer is in contact with the metal plate for the can, and the laminator is used to roll Heat lamination was performed at a pressure of 5 kg / cm ² and a roll temperature of 200 ° C., followed by heat treatment at 210 ° C. for 2 minutes to obtain a laminate.

The resulting laminate was drawn to a diameter of 100 mm, height of 10 mm, 12 mm and 14 mm using a deep drawing Erichsen molding machine, retorted at 125 ° C. for 30 minutes, and appearance (film peeling, blistering) Was visually evaluated.
○ ・ ・ ・ ・ No peeling.
○ △ ・ ・ ・ Slightly peeled.
Δ: ... 30% peeling at the aperture.
Δ × ... 60% peeled off at the throttle.
× ··· Front peeling.
○ and ○ △ are practically acceptable.

<Trapability>
In the printed materials X1 to X16 (Examples) and Z1 to Z16 (Comparative Examples), the overprinting effect of the gold ink composition / silver ink composition at a laser plate depth of 10 μm (bad wetting spread and roughness) was evaluated.
○ ···· 100% wetting and spreading of silver ink.
○ △ ... 90% wetting and spreading of silver ink.
Δ: Silver ink wet spread is 50%.
△ × ・ ・ ・ Wet spread of silver ink is 30%.
× ······ Silver ink is halftone.
○ and ○ △ are ranges where there is no practical problem.

  From the evaluation results, it is an ink composition for a metal film attached to a polyester film containing a pigment (A), a binder resin (B), an additive (C), and an organic solvent (D), and the pigment (A) is unsaturated. Polyester film pasting including aluminum particles (a1) surface-treated with fatty acids, and additive (C) containing silica particles (c1) having a silanol group and an average particle diameter of 1 μm to 5 μm and a silane coupling agent (c2) The ink composition for metal plates has excellent overlay printing suitability, and is a printing ink composition having excellent cosmetics (brightness), tape adhesion, blocking resistance, retort resistance, and trapping properties. I understood.

Claims (6)

An ink composition for a polyester film for laminating on a metal plate, comprising a pigment (A), a binder resin (B), an additive (C), and an organic solvent (D), and the following (1) and ( 2) An ink composition for a polyester film .
(1) The pigment (A) contains aluminum particles (a1) surface-treated with an unsaturated fatty acid. (2) The additive (C) includes silica particles (c1) having a silanol group and an average particle diameter of 1 μm to 5 μm and a silane coupling agent (c2). The binder resin (B) includes a polyurethane resin (b1),
The ink composition for a polyester film according to claim 1, wherein the silane coupling agent (c2) contains a substituted or unsubstituted amino group-containing silane coupling agent (c2-1). The polyurethane resin (b1) has at least one ethyleneimine group in the molecule;
The substituted or unsubstituted amino group-containing silane coupling agent (c2-1) contains a compound (c2-1-1) represented by the following general formula 1. Ink composition for polyester film .
General formula 1


(In the formula, R ¹ represents a methoxy group or an ethoxy group, n represents an integer of 1 to 6, R ² and R ³ each independently represents a hydrogen atom, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted group. Represents a substituted alkyl group.) The claims 1-3 polyester film ink composition according to any one, the printed matter obtained by printing on the polyester film. The laminated body formed by affixing with a metal plate on the printing surface of the printed matter of Claim 4 via an adhesive agent. A metal can comprising the laminate according to claim 5.