JP2019112489A - Liquid ink composition - Google Patents

Abstract

To provide a liquid ink composition which can be applied to a wide range of films, is excellent in adhesion and blocking resistance on various high functional barrier films, has a high laminate strength before and after hot water treatment in a package agent having an aluminum structure, and is excellent in retort resistance.SOLUTION: A liquid ink composition contains a polyurethane resin (A) having a polyester polyol structure containing long chain glycol (a) having an average degree of polymerization of 4.0 or more as a reaction raw material.SELECTED DRAWING: None

Description

  The present invention relates to a gravure ink for flexible packaging laminate applications and a liquid ink composition for flexographic inks. In particular, the present invention relates to a liquid ink composition for various films coated with an inorganic or organic barrier coating material which tends to have a reduced adhesion.

In general, a liquid ink for laminating use used for producing a soft packaging material is mainly used a urethane resin or a urethane urea resin.
And these urethane resins or urethane urea resins are manufactured using various reaction raw materials in order to give each characteristic.
For example, a binder for a printing ink comprising a polyethylene glycol (hereinafter referred to as PEG) -containing polyurethane resin and a vinyl chloride-vinyl acetate copolymer resin as components, wherein the PEG-containing polyurethane resin has at least (A) a number average molecular weight 1000 to 6000 Of polyester polyol, (B) PEG, (C) diisocyanate compound, and (D) chain extender, wherein the content ratio of (B) PEG is PEG-containing polyurethane resin 100 mass The binder for printing inks which is the range of 1-40 mass parts with respect to part is illustrated (for example, patent document 1).
In the polyurethane resin obtained by reacting (A) polyester polyol having a number average molecular weight of 2,000 to 10,000, (B) organic diisocyanate, and (C) chain extender, (A) is (a) glycol and (b) A binder for a printing ink, which is a polyester polyol obtained by reacting a dibasic acid and in which at least 25% by mass of the glycol (a) is a glycol having an ether bond in the molecule is exemplified (for example, Patent Document 2) ).
Furthermore, in the ink composition for laminating for soft packaging which contains an organic solvent other than a binder resin, a colorant and an aromatic organic solvent as a main component, polypropylene glycol (hereinafter referred to as PPG) -containing polyurethane resin and chloride having hydroxyl groups as the binder resin. A vinyl chloride / vinyl acetate copolymer resin is contained as an essential component, and the hydroxyl value of the vinyl chloride / vinyl acetate copolymer resin having a hydroxyl group is 50 to 200 mg equivalent KOH / g, and the vinyl chloride content relative to 100 parts by weight of the copolymer resin The ink composition for laminates for soft packaging whose ratio is 80 to 95 parts by weight is exemplified (for example, Patent Document 3).

  Furthermore, in recent years, the use of aromatic solvents such as toluene and ketone solvents such as methyl ethyl ketone is being restricted from the viewpoints of both the operational hygiene at the time of printing and the harmfulness of the packaging material. For example, from the viewpoint of printability, aromatic solvents as solvents, ketones such as aromatic solvents as ketone solvents and liquid solvents of ketone solvents type, acetates such as ethyl acetate and propyl acetate instead of ketone solvents, isopropyl alcohol, normal alcohols Alcohol solvents such as propyl alcohol or mixed solvents thereof tend to be used.

Various films such as polyethylene terephthalate, polypropylene and nylon are used for the production of the soft packaging material, and the printing ink is required to have adhesiveness to these various printing substrates. On the other hand, in recent years, there has been a tendency for high-performance films provided with various barrier properties to increase as films used for film packages. In these high-performance films, an inorganic or organic barrier coating agent is applied on the surface, and when the high-performance films are used as gravure for gravure printing or flexo printing, the adhesion between the original film and ink is impaired. It can often occur. These high-performance films exist in a wide variety depending on the type of industry and intended use, such as an oxygen barrier that blocks air to prevent deterioration of contents for food and electronic components, and a water vapor barrier that blocks water vapor. Also, many of them are non-public technically, and it is difficult to maintain adhesion compared to general film printing.

  Even with the use of urethane resins made of the various reaction raw materials described above, it is not easy to maintain the adhesion strength universally to the increasing variety of films.

International Publication WO2015 / 068412 Japanese Patent Application Laid-Open No. 2010-270216 Japanese Patent Application Laid-Open No. 2005-298618

  The present invention can be applied to a wide variety of films, and in particular, is excellent in adhesion and blocking resistance on various high function barrier films, and in the package of aluminum constitution, the laminate strength before and after the hydrothermal treatment is high. An object of the present invention is to provide a liquid ink composition having excellent retort resistance.

  As a result of intensive studies to solve the problems described above, the present inventors have found that, in a liquid ink composition, a polyester polyol structure using a long chain glycol (a) having an average degree of polymerization of 4.0 or more as a reaction raw material By using the polyurethane resin (A) which has, it discovered that it was effective in problem solution.

  That is, the present invention relates to a liquid ink composition comprising a polyurethane resin (A) having a polyester polyol structure which uses as a reaction raw material a long chain glycol (a) having an average polymerization degree of 4.0 or more.

Furthermore, the present invention relates to a liquid ink composition containing a vinyl chloride vinyl acetate copolymer resin (B).

  Furthermore, the present invention relates to a liquid ink composition containing a colorant (C) and an organic solvent (D).

  Furthermore, in the present invention, the content ratio of the long chain glycol (a) having an average polymerization degree of 4.0 or more is 1 to 60 mass with respect to 100 mass parts of polyester polyol which is a reaction raw material of the polyurethane resin (A). The present invention relates to a liquid ink composition that is in the range of 1 part.

  Furthermore, the present invention relates to a liquid ink composition in which the long chain glycol (a) having an average degree of polymerization of 4.0 or more is a polyether polyol having an average degree of polymerization of 4.0 or more.

  Furthermore, in the present invention, the long chain glycol (a) having an average degree of polymerization of 4.0 or more is selected from the group consisting of polyethylene glycols having an average degree of polymerization of 4.0 or more, polypropylene glycol, and polytetramethylene ether glycol. The present invention relates to a liquid ink composition which is any one or more of the

  Furthermore, according to the present invention, the vinyl chloride component in the copolymer resin is that the vinyl chloride / vinyl acetate copolymer resin (B) has a hydroxyl value, the hydroxyl value is 50 to 200 mg equivalent KOH / g, and The liquid ink composition according to any one of claims 1 to 6, wherein the content ratio of the liquid is 80 to 95 parts by mass.

  Furthermore, the present invention relates to a liquid ink composition in which the organic solvent (D) does not contain an aromatic organic solvent and / or a ketone solvent.

  Furthermore, the present invention relates to a printed matter obtained by printing the liquid ink composition.

  Furthermore, the present invention relates to a laminate, which comprises the printed matter.

  According to the present invention, it can be applied to a wide variety of films, and in particular, it is excellent in adhesion and blocking resistance on various high function barrier films, and in the package of aluminum constitution, the laminate strength before and after hot water treatment is high, A liquid ink composition having excellent retort resistance can be obtained.

  The present invention will be described in detail. The term "ink" used in the following description refers to "printing ink". Moreover, "part" and "%" show all "mass part" and "mass%."

  It is essential that the liquid ink composition of the present invention contains a polyurethane resin (A) having a polyester polyol structure using a long chain glycol (a) having an average polymerization degree of 4.0 or more as a reaction raw material.

Generally, in order to obtain a polyurethane resin, conventionally known materials such as polyether type and / or polyester type diol compounds (number average molecular weight 1,000 to 4,000), diisocyanate compounds and chain extenders, reaction terminators, etc. And manufactured by the method.
Representative examples of the above-mentioned polyether type diol include polyethylene glycol, polypropylene glycol, polyoxy tetramethylene glycol and the like, and as representative examples of polyester type diol, dibasic acids such as adipic acid, phthalic anhydride and isophthalic acid And condensation products of ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol and the like.
As polyurethane resin (A) used by the liquid ink composition of this invention, long-chain glycol (a) whose average polymerization degree is 4.0 or more is used as a reactive raw material as polyester diol.
The average polymerization degree of 4.0 or more long chain glycol (a) _{is, - (C m H 2m O} ) n - long-chain glycol having a repeating structure, that the polyalkylene glycol is preferred. Incidentally average degree of polymerization _{- (C m H 2m O)} -, i.e. represents the number of repeating units n of the alkylene group, that n number is 4.0 or more.
Specifically, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol and the like can be mentioned, and they may be used alone or in combination.

  The long chain glycol (a) itself having an average degree of polymerization of 4.0 or more may be a polyether polyol.

  Further, the content ratio of the long chain glycol (a) having an average polymerization degree of 4.0 or more is in the range of 1 to 60 parts by mass with respect to 100 parts by mass of polyester polyol which is a reaction raw material of the polyurethane resin (A). The content is preferably 5 to 50 parts by mass. If it is 1 part by mass or more and 60 parts by mass or less, the adhesion on the transparent vapor deposition film, the blocking resistance, and the laminate strength in the laminated film configuration containing aluminum in the substrate will be excellent.

Among the long chain glycols (a) having an average polymerization degree of 4.0 or more, the average polymerization degree is preferably 4 to 204, and more preferably 4 to 68.
If the average degree of polymerization is 4 or more and 204 or less, in particular, the laminate strength tends to be excellent in the laminated film configuration in which aluminum is contained in the substrate.

  As a combined polyol which is optionally used in the polyurethane resin (A) used in the liquid ink composition of the present invention, various known polyols generally used in the production of polyurethane resins can be used, and one kind of polyol can be used. Or you may use together 2 or more types. For example, polyether polyols of polymers or copolymers of methylene oxide, ethylene oxide, tetrahydrofuran and the like (1); ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2 methyl-1,3 propane Diol, 2ethyl-2butyl-1,3 propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5 pentanediol, hexanediol, octanediol 1,4-Butindiol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4- Butantriol, Saturated or unsaturated low molecular weight polyols (2) such as rubitol and pentaethrytol; these low molecular weight polyols (2) and adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, By dehydration condensation or polymerization of succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, sebacic acid, trimellitic acid, polymellitic carboxylic acids such as trimellitic acid, or their anhydrides Polyester polyols (3) obtained: ring-opening polymerization of cyclic ester compounds, for example, lactones such as polycaprolactone, polyvalerolactone and poly (β-methyl-γ-valerolactone) (4 And low molecular weight polyols (2) etc., for example, dimethyl carbonate, Polycarbonate polyols (5) obtained by reaction with carbonate, ethylene carbonate, phosgene etc .; polybutadiene glycols (6); glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A (7); in one molecule Acrylic polyol obtained by copolymerizing one or more of hydroxyethyl, hydroxy propyl acrylate, acrylic hydroxy butyl, etc., or their corresponding methacrylic acid derivatives etc. with, for example, acrylic acid, methacrylic acid or esters thereof (8) etc.

  Among the polyester polyols (3), a high molecular weight diol obtained from a diol (glycols) and a dibasic acid is a low molecular weight compound having three or more hydroxyl groups up to 5 mol% of the diol. It can be substituted with polyols (2).

  As a diisocyanate compound used for the polyurethane resin (A) in the ink composition for laminates for soft packaging of the present invention, various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclics generally used for the production of polyurethane resins Diisocyanate etc. are mentioned. For example, 1,5-naphthyl diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzylisocyanate, 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, Maryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethyl xylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate And bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, and dimeric isocyanate obtained by converting carboxyl group of dimer acid to isocyanate group. These diisocyanate compounds can be used alone or in combination of two or more.

As a chain extender used for polyurethane resin (A) in the liquid ink composition of the present invention, ethylene diamine, propylene diamine, hexamethylene diamine, diethylene triamine, triethylene tetramine, isophorone diamine, dicyclohexylmethane-4,4'-diamine Other than these, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2- Also, amines having a hydroxyl group in the molecule such as hydroxypyropirethylenediamine, di-2-hydroxypyropirethylenediamine, di-2-hydroxypropylethylenediamine It can be used. These chain extenders can be used alone or in combination of two or more.
Moreover, a monovalent active hydrogen compound can also be used as an end capping agent for the purpose of terminating the reaction. Such compounds include, for example, dialkylamines such as di-n-butylamine and alcohols such as ethanol and isopropyl alcohol. Furthermore, especially when it is desired to introduce a carboxyl group into the polyurethane resin, amino acids such as glycine and L-alanine can be used as the reaction terminator. These end capping agents can be used alone or in combination of two or more.

  The polyurethane resin (A) in the liquid ink composition of the present invention is obtained, for example, by reacting polypropylene glycol and a combination polyol and a diisocyanate compound at a ratio such that the isocyanate group is excessive to obtain a prepolymer of terminal isocyanate groups. The polymer is used in a suitable solvent, that is, an ester solvent such as ethyl acetate, propyl acetate or butyl acetate which is usually used as a solvent for gravure ink; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; methanol, ethanol Alcohol solvents such as isopropyl alcohol and n-butanol; Hydrocarbon solvents such as toluene, xylene, methylcyclohexane and ethylcyclohexane; or a mixed solvent of these, chain extenders and Or) a two-step method of reacting with an end capping agent, or a one-step method of reacting polypropylene glycol and a combination polyol, diisocyanate compound, chain extender and / or end capping agent all at once in a suitable solvent as described above Be done. Among these methods, in order to obtain a uniform polyurethane resin, the two-stage method is preferable. When the polyurethane resin is produced by a two-step method, the reaction is carried out so that the total (equivalent ratio) of the amino groups of the chain extender and / or the end capping agent is 1 / 0.9 to 1.3. Is preferred. When the equivalent ratio of isocyanate group to amino group is smaller than 1 / 1.3, the chain extender and / or endblocker remain unreacted, yellowing of the polyurethane resin, odor after printing It may occur. Furthermore, in recent years, it is more preferable not to use aromatic solvents such as toluene and xylene and ketone solvents from the viewpoint of working environment.

The weight average molecular weight of the polyurethane resin (A) thus obtained is preferably in the range of 15,000 to 100,000, and more preferably in the range of 15,000 to 80,000. When the weight average molecular weight of the polyurethane resin is less than 15,000, the blocking resistance of the resulting ink composition, the strength of the print film, the oil resistance, etc. tend to be low, and when it exceeds 100,000. The viscosity of the resulting ink composition tends to be high, and the gloss of the printed film tends to be low.
The content of the polyurethane resin (A) in the ink used in the liquid ink composition of the present invention is 4% by mass or more based on the total mass of the ink from the viewpoint of sufficient adhesion of the ink to the printing material The content is preferably 25% by mass or less, and more preferably 6 to 15% by mass from the viewpoint of the ink viscosity and the working efficiency at the time of production and printing of the ink.

Furthermore, in the liquid ink composition of the present invention, a vinyl chloride vinyl acetate copolymer resin (B) may be added.
The addition of the vinyl chloride / vinyl acetate copolymer resin (B) improves the blocking resistance and retort resistance. In particular, when the vinyl chloride / vinyl acetate copolymer resin (B) contains a hydroxyl group, the heat resistance such as retort resistance is remarkably improved.

  The vinyl chloride / vinyl acetate copolymer resin (B) having a hydroxyl group has a hydroxyl value of 50 to 200 mg KOH / g, and the content ratio of the vinyl chloride component in the copolymer resin is 80 to 95 mass%. Things are preferred.

  The vinyl chloride vinyl acetate copolymer resin (B) which has a hydroxyl group used for the liquid ink composition of this invention can be obtained by two types of methods. One is obtained by copolymerizing vinyl chloride monomer, vinyl acetate monomer and vinyl alcohol in appropriate proportions. The other is obtained by partially saponifying vinyl acetate after copolymerization of vinyl chloride and vinyl acetate. In the vinyl chloride / vinyl acetate copolymer resin having a hydroxyl group, the properties of the resin film and the resin dissolution behavior are determined by the monomer ratio of vinyl chloride, vinyl acetate and vinyl alcohol. That is, vinyl chloride imparts toughness and hardness to the resin film, vinyl acetate imparts adhesiveness and flexibility, and vinyl alcohol imparts good solubility in polar solvents.

  When liquid ink is used as a laminating ink for soft packaging, it is necessary to satisfy all the properties of adhesiveness, blocking resistance, laminate strength, boil retort aptitude, print aptitude, and vinyl chloride vinyl acetate copolymer having a hydroxyl group. The resin has a proper monomer ratio. That is, 80 to 95 parts by mass of vinyl chloride is preferable with respect to 100 parts by mass of vinyl chloride-vinyl acetate copolymer resin having a hydroxyl group. If the amount is less than 80 parts by mass, the toughness of the resin coating tends to be poor, and the blocking resistance tends to decrease. If the amount is more than 95 parts by mass, the resin coating tends to be too hard, resulting in a decrease in adhesion. The hydroxyl value obtained from vinyl alcohol is preferably 50 to 200 mg KOH / g. If it is less than 50 mg KOH / g, the solubility in polar solvents will be poor and the printability tends to be poor. If it exceeds 200 mg KOH / g, the water resistance tends to be reduced, and the boil and retort suitability tends to be poor.

  The colorant (D) used in the liquid ink composition of the present invention may be either a color pigment or a white pigment. If these pigments are not added, they can also be used as overcoat varnish applications.

  As a coloring agent (D) used for the liquid ink composition of this invention, the organic pigment and dye currently used for general ink, coating material, a recording agent, etc. can be mentioned. Examples of organic pigments include azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene pigments, perinone pigments, quinacridone pigments, thioindigo pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, azomethine azo pigments, dictopyrrolopyrrole pigments, and isoindoline pigments. And pigments.

As a color index name,
C. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 42, 74, 83;
C. I. Pigment Orange 16;
C. I. Pigment Red 5, 22, 38, 48: 1, 48: 2, 48: 4, 49: 1, 53: 1, 57: 1, 63: 1, 81, 101;
C. I. Pigment Violet 19, 23;
C. I. Pigment Blue 23, 15: 1, 15: 3, 15: 4, 17: 1, 18, 27, 29
C. I. Pigment Green 7, 36, 58, 59;
C. I. Pigment Black 7;
C. I. Pigment White 4, 6, 18 and the like.

  C.I. I. Pigment Blue 15: 3 (copper phthalocyanine), yellow ink, C.I. I. Pigment Yellow 83, C.I. I. It is preferable to use Pigment Red 57: 1. It is preferable to use carbon black for the black ink, aluminum for the gold and silver inks, and mica for the pearl ink from the viewpoint of cost and coloring power. Aluminum is in the form of powder or paste, but is preferably used in the form of paste in terms of handleability and safety, and whether leafing or non-leafing is used is appropriately selected in terms of brightness and density.

In addition, as the white pigment used for the liquid ink composition of the present invention, for example, titanium oxide, zinc sulfide, lead white, zinc flower, lithobon, antimony white, basic lead sulfate, basic lead silicate, barium sulfate , Calcium carbonate, gypsum, silica, etc.
The average particle diameter of the pigment is preferably in the range of 10 to 200 nm, more preferably about 50 to 150 nm.
Moreover, as an addition amount of the color pigment, in order to obtain sufficient image density and light resistance of a printed image, it is preferable to be contained in the range of 1 to 20% by mass of the total amount of the ink.

  As the organic solvent (E) used in the liquid ink composition of the present invention, various organic solvents can be used. For example, aromatic organic solvents such as toluene and xylene, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone Ester solvents such as ethyl acetate, n-propyl acetate, butyl acetate and propylene glycol monomethyl ether acetate, alcohol solvents such as n-propanol, inopropanol, n-butanol and propylene glycol monomethyl ether Can be used alone or in combination of two or more. In recent years, it is more preferable not to use aromatic solvents such as toluene and xylene or ketone solvents from the viewpoint of working environment.

  Examples of the resin used in combination with the liquid ink composition of the present invention as required include the aforementioned polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, and resins other than nitrified cotton, such as chlorinated polypropylene resin, ethylene- Vinyl acetate copolymer resin, vinyl acetate resin, polyamide resin, acrylic resin, polyester resin, alkyd resin, polyvinyl chloride resin, rosin resin, rosin modified maleic resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, Petroleum resin etc. can be mentioned. The combination resin can be used alone or in combination of two or more. The content of the combined resin is preferably 0.1 to 25% by mass, more preferably 2 to 15% by mass, based on the total mass of the ink.

  In the present invention, if necessary, combined resins, extender pigments, pigment dispersants, leveling agents, antifoaming agents, waxes, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc. can also be included. .

  Specifically, in the liquid ink composition of the present invention, the polyurethane resin, the vinyl chloride vinyl acetate copolymer resin and / or the nitrification cotton are previously mixed with various organic solvents such as ethyl acetate, methyl ethyl ketone, toluene and IPA. If it is a varnish composition, a varnish composition can be obtained by adding and stirring various additives while stirring the said solution with a dispersion stirrer. If it is an ink composition, an ink composition will be obtained by adding a coloring agent and fully disperse | distributing.

  Among the liquid ink compositions of the present invention, when a colorant (D) is used, yellow, red, amber, black, and white as basic colors of the process depending on the type of colorant (D) to be used. There are five colors, and there are three colors of red (orange), grass (green) and purple as process gamut outer color. Furthermore, transparent yellow, peony, mochi, tea, gold, silver, pearl, almost transparent medium for adjusting color density (including an extender pigment if necessary), etc. are prepared as base colors. The ink for boiling retort is appropriately selected in consideration of the migration property of the pigment and the heat resistance. The base ink of each color is diluted with a dilution solvent to a viscosity and concentration suitable for gravure printing or flexo printing, and supplied alone or mixed to each printing unit.

The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the grinding media of the dispersing machine, the filling ratio of the grinding media, the dispersion treatment time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, etc. be able to. As a dispersing machine, a roller mill, a ball mill, a pebble mill, an attritor, a sand mill etc. can be used generally, for example.
In the case where air bubbles or unexpectedly large particles are contained in the ink, it is preferable to remove by filtration etc. in order to reduce the print quality. The filter can use a conventionally well-known thing.

The viscosity of the ink produced by the above method is in the range of 10 mPa · s or more from the viewpoint of preventing sedimentation of the pigment and appropriately dispersing it, and 1000 mPa · s or less from the viewpoint of workability at the time of ink production or printing preferable. The above viscosity is a viscosity measured at 25 ° C. with a B-type viscometer manufactured by Tokimec.
The viscosity of the ink can be adjusted by appropriately selecting the type and amount of the raw material used, for example, a polyurethane resin, a colorant, an 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.

  While polyester resin films are particularly preferred as usable plastic films, the liquid ink composition of the present invention is particularly useful for polypropylene films in which adhesion tends to decrease, and other polypropylene, nylon, polyethylene resin films It can be widely used for various high-performance films in which an inorganic or organic barrier coating material is coated on the surface of the film.

The present invention will be more specifically described by way of examples. Hereinafter, “parts” and “%” are all based on mass.
The measurement of the weight average molecular weight (in terms of polystyrene) and the number average molecular weight (in terms of polystyrene) by GPC (gel permeation chromatography) in the present invention was performed under the following conditions using Tosoh Co., Ltd. HLC 8220 system.
Separation column: Four Tosoh Co., Ltd. product TSKgelGMH _HR- N is used. Column temperature: 40 ° C. Moving bed: tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow rate: 1.0 ml / min. Sample concentration: 1.0% by weight. Sample injection volume: 100 microliters. Detector: Differential refractometer.
The viscosity was measured at 25 ° C. with a Tokimec B-type viscometer.

Synthesis Example 1 60 mass% of polyethylene glycol in polyester polyol (urethane bond concentration: 2.32 mmol / g): Synthesis of polyurethane resin solution A1 A stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet pipe were provided. In a four-necked flask, 60.0 parts of a polyester polyol consisting of polyethylene glycol (hydroxyl number: 560.0 mg KOH / g, average polymerization degree: 4.1), adipic acid (hydroxyl number: 280.5 mg KOH / g) and neopentyl Charge 40.0 parts of a polyester polyol consisting of glycol and adipic acid (hydroxyl value: 56.1 mg KOH / g) and 37.1 parts of hexamethylene diisocyanate, and react at 90 ° C. for 10 hours under a nitrogen stream to obtain an isocyanate group content of 3 .12% by mass of urethane prepolymer is produced Then, 73.8 parts of ethyl acetate was added thereto to prepare a uniform solution of urethane prepolymer. Then, the above urethane prepolymer solution is added to a mixture of 8.73 parts of isophorone diamine, 0.59 parts of di-n-butylamine, 131.2 parts of ethyl acetate and 136.6 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution A1. The obtained polyurethane resin solution A1 had a resin solid concentration of 30.2% by mass, and the resin solid content had a weight average molecular weight (Mw) of 61,000.

Synthesis Example 2 5% by mass of polyethylene glycol in polyester polyol (urethane bond concentration: 1.41 mmol / g): Synthesis of polyurethane resin solution A2 A stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet pipe were provided. In a four-necked flask, 5.0 parts (hydroxyl number: 13.9 mg KOH / g) of polyester polyol consisting of polyethylene glycol (hydroxyl number: 282.0 mg KOH / g, average degree of polymerization: 8.6) and adipic acid Charge 95.0 parts of a polyester polyol consisting of methyl-1,5 pentanediol, adipic acid (hydroxyl value: 112.2 mg KOH / g) and 28.9 parts of isophorone diisocyanate, and react at 90 ° C. for 10 hours under nitrogen stream, Produces a urethane prepolymer with an isocyanate group content of 2.25% by mass After that, 69.4 parts of ethyl acetate was added thereto to obtain a uniform solution of urethane prepolymer. Then, the above urethane prepolymer solution is added to a mixture of 6.13 parts of isophorone diamine, 0.25 parts of di-n-butylamine, 120.0 parts of ethyl acetate and 126.3 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution A2. The obtained polyurethane resin solution A2 had a resin solid concentration of 30.0% by mass, and the weight average molecular weight (Mw) of the resin solid was 70,000.

Synthesis Example 3 40% by mass of polyethylene glycol in polyester polyol (urethane bond concentration: 0.43 mmol / g): Synthesis of polyurethane resin solution A3 A stirrer, a thermometer, a reflux condenser and a nitrogen gas introduction pipe were provided. In a four-necked flask, 40.0 parts of a polyester polyol consisting of polyethylene glycol (hydroxyl value: 55.3 mg KOH / g, average polymerization degree: 45.7) and adipic acid (hydroxyl value: 18.7 mg KOH / g) 60.0 parts (hydroxyl value: 37.1 mg KOH / g) of polyester polyol consisting of methyl-1,3 propanediol and adipic acid and 15.4 parts of isophorone diisocyanate are charged, and reacted at 90 ° C. for 10 hours under nitrogen stream, Manufacture of urethane prepolymer with an isocyanate group content of 3.12% by mass After that, 62.1 parts of ethyl acetate was added to this to make a uniform solution of urethane prepolymer. Then, the above urethane prepolymer solution is added to a mixture of 7.37 parts of isophorone diamine, 0.42 parts of di-n-butylamine, 110.4 parts of ethyl acetate and 115.0 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution A3. The obtained polyurethane resin solution A3 had a resin solid concentration of 30.2% by mass, and the resin solid content had a weight average molecular weight (Mw) of 64,000.

Synthesis Example 4 20% by mass of polypropylene glycol in polyester polyol (urethane bond concentration: 0.49 mmol / g): Synthesis of polyurethane resin solution A4 A stirrer, a thermometer, a reflux condenser and a nitrogen gas introduction pipe were provided. In a four-necked flask, 20.0 parts of a polyester polyol consisting of polypropylene glycol (hydroxyl value: 360.0 mg KOH / g, average polymerization degree: 5.1) and adipic acid (hydroxyl value: 75.0 mg KOH / g) and neopentyl Charge 80.0 parts of polyester polyol consisting of glycol, 2-methyl-1,3 propanediol and adipic acid (hydroxyl value: 22.4 mg KOH / g), 7.7 parts of isophorone diisocyanate and 5.8 parts of hexamethylene diisocyanate, Let react at 90 ° C for 10 hours under air flow, After producing a urethane prepolymer having an isocyanate group content of 2.95% by mass, 61.1 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. Then, the above urethane prepolymer solution is added to a mixture of 6.77 parts of isophorone diamine, 0.56 parts of di-n-butylamine, 108.0 parts of ethyl acetate and 112.8 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution A4. The obtained polyurethane resin solution A4 had a resin solid content concentration of 30.4% by mass, and the resin solid content had a weight average molecular weight (Mw) of 58,000.

Synthesis Example 5 50 mass% of polypropylene glycol in polyester polyol (urethane bond concentration: 0.72 mmol / g): Synthesis of polyurethane resin solution A5 A stirrer, a thermometer, a reflux condenser and a nitrogen gas introduction pipe were provided. In a four-necked flask, 50.0 parts (hydroxyl value: 37.9 mg KOH / g) of a polyester polyol consisting of polypropylene glycol (hydroxyl value: 111.0 mg KOH / g, average degree of polymerization: 17.1) and adipic acid and neopentyl Charge 50.0 parts of polyester polyol (hydroxyl value: 56.1 mg KOH / g) consisting of glycol and adipic acid, and 11.4 parts of tolylene diisocyanate, and react at 80 ° C. for 8 hours under nitrogen stream to obtain isocyanate group content 1 After producing a .78% by weight urethane prepolymer, Then, 60.0 parts of ethyl acetate was added thereto to obtain a uniform solution of urethane prepolymer. Then, the above urethane prepolymer solution is added to a mixture of 4.09 parts of isophorone diamine, 0.46 parts of di-n-butylamine, 102.4 parts of ethyl acetate and 108.3 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution A5. The resulting polyurethane resin solution A5 had a resin solid concentration of 30.1% by mass, and the resin solid content had a weight average molecular weight (Mw) of 58,000.

Synthesis Example 6 20 mass% of polytetramethylene ether glycol in polyester polyol (urethane bond concentration: 1.35 mmol / g): Synthesis of polyurethane resin solution A6 Stirrer, thermometer, reflux condenser and nitrogen gas inlet tube In a four-necked flask equipped with a polytetramethylene ether glycol (hydroxyl value: 174.0 mg KOH / g, average polymerization degree: 8.7), 20.0 parts of a polyester polyol consisting of adipic acid (hydroxy value: 44.9 mg KOH) / G), 1, 2-propanediol, 80.0 parts of polyesterpolyol consisting of adipic acid (hydroxyl value: 112.5 mg KOH / g), 8.3 isophorone diisocyanate, 15.2 parts of tolylene diisocyanate, charged with nitrogen gas The reaction is carried out at 80.degree. C. for 13 hours under After preparing a urethane prepolymer having a content of 2.48% by weight, 66.5 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. Then, the above urethane prepolymer solution is added to a mixture of 6.14 parts of isophorone diamine, 0.70 parts of di-n-butylamine, 115.9 parts of ethyl acetate and 121.6 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution A6. The resulting polyurethane resin solution A6 had a resin solid concentration of 30.1% by mass, and the resin solid content had a weight average molecular weight (Mw) of 51,000.

Synthesis Example 7 A total of polyethylene glycol and polypropylene glycol of 60% by mass (urethane bond concentration: 0.36 mmol / g) in polyester polyol: Synthesis of polyurethane resin solution A7 Stirrer, thermometer, reflux condenser and nitrogen Polyethylene glycol (hydroxyl number: 282.0 mg KOH / g, average degree of polymerization: 8.6), polypropylene glycol (hydroxyl number: 360.0 mg KOH / g, average degree of polymerization: 5) in a four-necked flask equipped with a gas inlet tube .1), 60.0 parts of polyester polyol consisting of adipic acid (hydroxyl number: 27.9 mg KOH / g), 40.0 parts of polyester polyol consisting of 3-methyl-1,5 pentanediol and adipic acid (hydroxyl number: 18) .9 mg KOH / g) and hexamethylene diisocyanate 11.1 parts are charged, and reacted under a nitrogen stream at 90 ° C. for 10 hours to produce a urethane prepolymer having an isocyanate group content of 3.36% by mass, and then 59.8 ethyl acetate is added thereto to give a urethane prepolymer It was a homogeneous solution of the polymer. Then, the above urethane prepolymer solution is added to a mixture of 7.48 parts of isophorone diamine, 0.63 parts of di-n-butylamine, 107.1 parts of ethyl acetate and 11.2 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution A7. The obtained polyurethane resin solution A7 had a resin solid content concentration of 30.3% by mass, and the resin solid content had a weight average molecular weight (Mw) of 55,000.

Synthesis Example 8 10 mass% of total of polyethylene glycol and polytetramethylene ether glycol in polyester polyol (urethane bond concentration: 0.81 mmol / g): Synthesis of polyurethane resin solution A8 Stirrer, thermometer, reflux cooling In a four-necked flask equipped with a vessel and a nitrogen gas inlet, polyethylene glycol (hydroxyl number: 560.0 mg KOH / g, average degree of polymerization: 4.1), polytetramethylene ether glycol (hydroxyl number: 174.0 mg KOH / g Average degree of polymerization: 8.7), 10.0 parts of polyester polyol consisting of adipic acid (hydroxyl value: 37.0 mg KOH / g), 90.0 parts of polyester polyol consisting of diethylene glycol, adipic acid (hydroxyl value: 55.7 mg KOH) / G) and isophorone After 15.5 parts of anate were charged and reacted at 90 ° C. for 15 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 1.59% by mass, ethyl acetate 62.2 was added thereto to prepare a urethane prepolymer. It was a homogeneous solution of the polymer. Then, the above urethane prepolymer solution is added to a mixture of 4.06 parts of isophorone diamine, 0.13 parts of di-n-butylamine, 105.4 parts of ethyl acetate and 111.7 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution A8. The resulting polyurethane resin solution A8 had a resin solid concentration of 30.4% by mass, and the resin solid content had a weight average molecular weight (Mw) of 73,000.

Synthesis Comparative Example 1 Use of non-esterified polyethylene glycol (urethane bond concentration: 0.41 mmol / g): Synthesis of polyurethane resin solution H1 Four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube Further, 85.0 parts (hydroxyl value: 22.4 mg KOH / g carbon atom number: 4) of polyester polyol obtained by reacting neopentyl glycol, 2-methyl-1, 3-propanediol and adipic acid are obtained.
To the obtained polyester polyol, 15.0 parts of polyethylene glycol (hydroxyl value: 56.1 mg KOH / g, average degree of polymerization: 45.0) and 12.1 parts of isophorone diisocyanate are charged, and reacted at 90 ° C. for 10 hours under nitrogen stream. Then, after preparing a urethane prepolymer having an isocyanate group content of 2.25% by mass, ethyl acetate 60.4 was added thereto to make a uniform solution of the urethane prepolymer. Then, the above urethane prepolymer solution is added to a mixture of 5.17 parts of isophorone diamine, 0.43 parts of di-n-butylamine, 104.4 parts of ethyl acetate and 1109.8 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution H1. The obtained polyurethane resin solution H1 had a resin solid concentration of 30.4% by mass, and the resin solid content had a weight average molecular weight (Mw) of 62,000.

Synthesis Comparative Example 2 Non-esterified polypropylene glycol (urethane bond concentration: 2.33 mmol / g): Synthesis of polyurethane resin solution H2 Four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube Thus, 50.0 parts (hydroxyl number: 18.9 mg KOH / g carbon atom number 6) of a polyester polyol consisting of, 3-methyl-1,5 pentanediol and adipic acid were obtained.
50.0 parts of polypropylene glycol (hydroxyl value: 360.0 mg KOH / g, average degree of polymerization: 5.1) and 34.2 parts of tolylene diisocyanate are added to the obtained polyester polyol, and 10 hours at 80 ° C. in a nitrogen stream. After reacting to prepare a urethane prepolymer having an isocyanate group content of 1.72% by mass, ethyl acetate 72.3 was added thereto to prepare a uniform solution of the urethane prepolymer. Then, the above urethane prepolymer solution is added to a mixture of 4.62 parts of isophorone diamine, 0.80 parts of di-n-butylamine, 123.1 parts of ethyl acetate and 130.3 parts of isopropyl alcohol, The reaction was allowed to stir for time to obtain a polyurethane resin solution H2. The obtained polyurethane resin solution H2 had a resin solid concentration of 30.5% by mass, and the resin solid content had a weight average molecular weight (Mw) of 50,000.

Preparation Example 1: Preparation of vinyl chloride vinyl acetate copolymer resin solution V
Acetic acid / vinyl acetate copolymer resin having a hydroxyl group to be used in combination with a polyurethane resin (resin monomer composition is% by mass vinyl chloride / vinyl acetate / vinyl alcohol = 92/3/5, hydroxyl value (mg KOH) = 64) The solution was made into a 15% solution with ethyl, and this was made into a salt and vinyl acetate resin solution V.

Example 1
25 parts of polyurethane resin solution A (solid content 30.2%), 10 parts of vinyl chloride / vinyl acetate copolymer resin solution G (solid content 15%), 35 parts of titanium oxide pigment JR-805, manufactured by Taika Co., Ltd., ethyl acetate The mixture comprising 10 parts of isopropyl alcohol and 10 parts of isopropyl alcohol is kneaded using a Dino Mill (manufactured by Willie E. Baccophenon Co., Ltd.), and 10 parts of ethyl acetate is further added to the obtained white meat base ink. Liquid white ink was created.

[Examples 2 to 8, Comparative Examples 1 and 2]
A liquid white ink was prepared in the same manner as in Example 1 according to Examples 2 to 8 and Comparative Examples 1 and 2 according to the composition shown in Tables 1 and 2.
The viscosity of the obtained printing ink is adjusted to 16 seconds (25 ° C.) with ethyl acetate with Zahn cup # 3 (manufactured by Rigosha Co., Ltd.), and shown in Tables 1 and 2 with a gravure proofer equipped with a plate depth of 35 μm gravure plate. Printed on various barrier films (W, X, Y, Z) and corona-treated polyester film (hereinafter referred to as PET film: manufactured by Toyobo Co., Ltd. trade name ester E5102 thickness 12 μm) and dried at 40 to 50 ° C. Obtained.
About the obtained printed matter, adhesion to various barrier films and blocking resistance, and laminating strength with PET film / aluminum / non-oriented polypropylene film (hereinafter, R-CPP: ZK-75 50 μm manufactured by Toray Synthetic Film Co., Ltd.) The appearance was evaluated after retort treatment. The results are shown in Tables 1 and 2. In addition, evaluation was performed by the following test method.

1) Adhesiveness (various barrier films)
After the printed matter was left to stand for 1 day, a cellophane tape (12 mm wide made by Nichiban Co., Ltd.) was attached to the printing surface, and the appearance of the printed film was visually determined when the tape was rapidly peeled off. The judgment criteria were as follows.
○: The printed film did not peel at all.
Fair: 50% or more and less than 80% of the area ratio of the printed film remained on the film.
X: Less than 50% of the area ratio of the printed film remained on the film.

2) Blocking resistance (various barrier films)
The film is overlaid so that the printed side and the non-printed side of the above printed matter are in contact, a load of 10 kgf / cm ² is applied, and aging is carried out for 12 hours under 40 ° C. environment. The state of was visually evaluated in three steps.
Good: Transfer of 0% of the ink to the non-printed surface No transfer is observed Δ: Transfer is observed at a ratio of less than 20% of area ratio x: Transfer is observed at a ratio of 20% or more of area ratio

3) Measurement of laminate strength The above-mentioned PET film printed matter is coated with a urethane-based dry lamination adhesive, Dick Dry LX-500 / KW-75 (made by DIC) so that the coating amount is 3.5 g / m ^2, and after drying An aluminum foil (hereinafter, AL: manufactured by Toyo Aluminum Industry Co., Ltd., aluminum foil C, 15 μm) was laminated by a dry laminating machine (manufactured by DIC Engineering) to obtain a laminate 1 of two layers. Next, an adhesive is similarly applied on the AL of the laminate 1, a non-oriented polypropylene film (hereinafter, R-CPP: Toray Synthetic Film ZK-75 50 μm) is laminated, and aged at 40 ° C. for 5 days, A three-layer composite laminate 2 was obtained. Thereafter, measurement of laminate strength was performed. The larger the number, the stronger the laminate strength.

4) Retort resistance (appearance evaluation after retort treatment of laminate)
The obtained laminate 2 was formed into a pouch of 120 mm × 120 mm and filled with 70 g of simulated food containing vinegar, salad oil and meat sauce at a weight ratio of 1: 1: 1. The prepared pouch was subjected to steam retort sterilization treatment at 135 ° C. for 30 minutes, and the degree of peeling was evaluated in three steps.
○: There is no peeling.
Δ: Small blister-like exfoliation.
X: There is peeling on the entire surface regardless of size.

  Tables 1 and 2 show the composition of each liquid white ink and the evaluation results.

Barrier film to be evaluated W: Dainippon Printing Co., Ltd. alumina-deposited transparent PET film IB-PET-PUB (thickness: 12 μm)
X: Mitsubishi Resins Co., Ltd. Silica vapor deposited transparent PET film Tech Barrier TX-R (thickness: 12 μm)
Y: Oike Kogyo Co., Ltd. silica vapor deposited transparent PET film MOS-TEB (thickness: 12 μm)
Z: Letterpress printing Co., Ltd. aluminum oxide vapor deposition transparent PET film GL-ARH (thickness: 12 μm)

OPP film to be evaluated U: Toyobo Co., Ltd. P2161 (thickness: 20 μm)

  In the examples, the adhesiveness to the transparent vapor deposition film, the blocking resistance, and the laminate strength before and after the hot water treatment in the package of the aluminum constitution were high, and the result was excellent in the retort resistance.

  The liquid ink composition of the present invention can be widely deployed in industrial products such as food packaging, sanitary cosmetics, electronic parts and the like.

Claims (10)

A liquid ink composition comprising a polyurethane resin (A) having a polyester polyol structure having as a reaction raw material a long chain glycol (a) having an average polymerization degree of 4.0 or more.
The liquid ink composition according to claim 1, further comprising a vinyl chloride / vinyl acetate copolymer resin (B).
The liquid ink composition according to claim 1, further comprising a colorant (C) and an organic solvent (D).
The content ratio of the long chain glycol (a) having an average polymerization degree of 4.0 or more is in the range of 1 to 60 parts by mass with respect to 100 parts by mass of polyester polyol which is a reaction raw material of the polyurethane resin (A). The liquid ink composition according to any one of Items 1 to 3.
The liquid ink composition according to any one of claims 1 to 4, wherein the long chain glycol (a) having an average degree of polymerization of 4.0 or more is a polyether polyol having an average degree of polymerization of 4.0 or more.
Any one or more of the long chain glycol (a) having an average degree of polymerization of 4.0 or more selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol having an average degree of polymerization of 4.0 or more The liquid ink composition according to any one of claims 1 to 5, which is
The vinyl chloride / vinyl acetate copolymer resin (B) has a hydroxyl value, the hydroxyl value is 50 to 200 mg equivalent KOH / g, and the content ratio of the vinyl chloride component in the copolymer resin is 80 to The liquid ink composition according to any one of claims 1 to 6, which is 95 parts by mass.
The liquid ink composition according to any one of claims 1 to 7, wherein the organic solvent (D) does not contain an aromatic organic solvent and / or a ketone solvent.
The printed matter formed by printing the liquid ink composition as described in any one of Claims 1-8.
  The laminated laminated body which has a printing layer formed by printing the liquid ink composition as described in any one of Claims 1-9.