JP5515817B2 - Gravure printing ink - Google Patents

Description

  The present invention relates to a gravure printing ink, and more specifically, can reduce printing defects due to static electricity generated during gravure ink printing, and further, stability over time with ink, adhesion to a printing film, blocking when a printed material is wound up. The present invention relates to a gravure printing ink that does not deteriorate the properties and the boilability of a laminate.

  In recent years, in the printing industry, the printing speed has been increased in order to improve productivity, and printing defects are likely to occur. There is a greater demand than ever for inks that are less prone to printing defects and that have good printing yields.

  In general, in solvent-type gravure inks, whiskers (hereinafter referred to as whiskers) that cause ink splashes from the printing surface of sharp image areas during ink transfer, and misting (hereinafter referred to as ink sprays) that contaminate printed matter. Printing defects due to static electricity such as misting) are likely to occur.

  Beard misting is affected by printing speed, ink viscosity, printing plate depth (ink application amount), printing room environment (temperature / humidity), printing machine charging condition, etc. Prevents whisker and misting by changing the ink viscosity, changing the printing conditions, such as spraying water around the printing machine, humidifying with a humidifier, and using a static elimination tape, and changing the printing viscosity. However, it was not enough to prevent beard misting.

  Patent Document 1 proposes a method using palm alkylbisbis (hydroxyethyl) methyl nitrate and palmalkylbis (hydroxyethyl) methyl chloride as a measure to prevent beard misting. However, in recent years, a further increase in printing speed has been demanded, and this is insufficient in effect, and an increase in the amount added causes problems such as a decrease in substrate adhesion.

  Patent Document 2 proposes that printing ink using a quaternary ammonium salt compound (sulfate) is printed on a plastic film to impart antistatic properties to the film. There is a description. Further, Patent Document 3 proposes to prevent the plastic film from being charged with a back-printed urethane gravure ink using a mixed composition of fatty acid dimethyl ammonium methosulfate and polyoxyethylene alkyl ether. However, when a quaternary ammonium salt compound (sulfate) is used, there is a problem that the temporal stability of the ink is deteriorated.

JP 2005-290082 A JP 2000-169834 A JP 2005-220275 A

  The present invention solves the above-described problems, and relates to gravure printing ink, and more specifically, gravure printing ink that can reduce defective printing due to static electricity generated during gravure ink printing and does not affect other physical properties. The purpose is to provide.

〔但し、R₁が炭素数C₈からC₂₂のアルキル基、R₂、R₃ がメチル基、R₄がC₁からC₁₈のアル
キル基または、ベンジル基である。〕
ただし、溶剤型グラビア印刷インキは、併用樹脂バインダーとして塩化ビニル−酢酸ビニル共重合体含有する。
また、４級アンモニウム塩を、インキ１００重量部に対して０．０５〜２．５重量部含有することを特徴とする溶剤型グラビア印刷インキである。
The solvent-type gravure printing ink of the present invention is a solvent-type gravure printing ink comprising a polyurethane resin as a main binder and containing a quaternary ammonium salt represented by the following general formula (I).

[However, R ₁ is an alkyl group having ₈ to ₂₂ carbon atoms, R ₂ and R ₃ are methyl groups, and R ₄ is an alkyl group having ₁ to ₁₈ carbon atoms or a benzyl group. ]
However, the solvent-type gravure printing ink contains a vinyl chloride-vinyl acetate copolymer as a combined resin binder.
The solvent-type gravure printing ink further comprises 0.05 to 2.5 parts by weight of a quaternary ammonium salt with respect to 100 parts by weight of the ink.

According to the present invention, printing defects due to static electricity generated during gravure ink printing can be reduced, and further, ink aging stability, adhesion to a printing film, blocking property when winding a printed material, boilability of a laminate, etc. A gravure printing ink that does not decrease was obtained.

  Details of the present invention will be described. “Ink” used in the following description means “gravure ink”. In the following description, “part” represents “part by weight” and “%” represents “% by weight”.

(Urethane)
Examples of the polyurethane resin include conventionally known methods such as JP-A-62-153366, JP-A-62-153367, JP-A-1-236289, JP-A-2-64173, and JP-A-2- 64174, JP-A-2-64175 and the like. Here, the polyurethane resin is a general term for a polyurethane resin and a polyurethane urea resin.
Specifically, a polyol and a diisocyanate compound are reacted in an excess ratio of isocyanate groups to obtain a prepolymer of a terminal isocyanate group, and the resulting prepolymer is used in a suitable solvent, that is, for non-toluene gravure ink. Ester solvents such as ethyl acetate, propyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; alcohol solvents such as methanol, ethanol, isopropyl alcohol and n-butanol; Hydrocarbon-based solvents such as methylcyclohexane, ethylcyclohexane, etc .; or a mixed solvent thereof in a two-stage method in which it is reacted with a chain extender and / or end-capping agent, or polyol, diisocyanate compound, chain extender and / or The end capping agent is produced by one-step process of reacting at a time in a suitable solvent of the above. Among these methods, it is preferable to use a two-stage method in order to obtain a uniform polyurethane resin. When a polyurethane resin is produced by a two-stage method, the equivalent ratio of isocyanate groups to hydroxyl groups is preferably 3/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1 in the first stage reaction. It is. Moreover, it is preferable to make it react so that the total (equivalent ratio) of the amino group of a chain extender and / or a terminal blocker may become a ratio of 1 / 0.9-1.3. When the equivalent ratio of isocyanate group to amino group is less than 1 / 1.3, the chain extender and / or end-capping agent remains unreacted, the polyurethane resin turns yellow, and odor occurs after printing There is a case to do. Polyester polyol is preferable as the polyol, and polyether polyol tends to be inferior in substrate adhesion, blocking resistance, and boil suitability.

  The weight average molecular weight of the polyurethane resin thus obtained is preferably in the range of 15,000 to 100,000. When the weight average molecular weight of the polyurethane resin is less than 15,000, there is a tendency that the blocking resistance of the ink composition obtained, the strength of the printed film, the oil resistance, and the like tend to be low. The viscosity of the resulting ink composition tends to increase, and the gloss of the printed film tends to decrease. The amount of urethane resin is an active ingredient and is preferably 3 to 30 parts in 100 parts of ink. More preferably, it is 6-21 parts.

(Quaternary ammonium salt)
Examples of the quaternary ammonium salt used in the present invention include monoalkyltrimethylammonium chloride (such as cetyltrimethylammonium chloride, cocoalkyltrimethylammonium chloride, stearyltrimethylammonium chloride, and behenyltrimethylammonium chloride), monoalkylbenzyldimethylammonium chloride (coconut chloride). Benzyl dimethyl ammonium, coconut benzyl dimethyl ammonium chloride, tetradecyl benzyl dimethyl ammonium chloride, etc.), dialkyl dimethyl ammonium chloride (didecyl dimethyl ammonium chloride, dicocoyl dimethyl ammonium chloride, distearyl dimethyl ammonium chloride, dioleyl dimethyl ammonium chloride, etc.), etc. However, it is not limited to these. Preferred are monoalkyltrimethylammonium chloride, monoalkylbenzyldimethylammonium chloride, and dialkyldimethylammonium chloride. More preferred is monoalkylbenzyldimethylammonium chloride. The quaternary ammonium salt is preferably used as an active ingredient in an amount of 0.05 to 2.5 parts with respect to 100 parts of ink. If it is 0.05 parts or less, there is little effect of reducing printing defects due to static electricity, and if it is 2.5 parts or more, adhesion to the substrate may be reduced.

(Vinyl chloride-vinyl acetate copolymer)
The resin of vinyl chloride-vinyl acetate copolymer varies in chemical resistance, toughness, adhesiveness, solubility, etc. depending on the molar ratio of vinyl chloride and vinyl acetate, the degree of polymerization, and the molecular weight. In addition, a vinyl acetate resin can be selected suitably from the kind of ink, a printing method, a printing structure, etc. Examples of commercially available vinyl chloride resin include SOLBIN C, CL, CH, CN, C5R, A, AL, TA2, TA3, TAO, TA5R, M, ME, MFK (manufactured by Nissin Chemical Industry Co., Ltd.), VINNOL E14. / 45, H14 / 36, H40 / 55, E15 / 45M (manufactured by WACKER), and the like, but are not limited thereto. The blocking resistance is improved by adding a vinyl chloride-vinyl acetate copolymer resin. The amount of resin added is preferably 0.2 to 24 parts by weight with respect to 100 parts by weight of ink as an active ingredient.

  In addition to polyurethane resin and vinyl chloride-vinyl acetate copolymer, binder resin of gravure printing ink of the present invention includes acrylic resin, acrylic modified urethane resin, styrene / acrylic resin, ethylene / acrylic resin, polyester resin, rosin modified maleic acid Resins, polyvinyl acetal resins, polyamide resins, cellulose resins such as hydroxyethyl cellulose, hydroxypropyl cellulose, nitrocellulose, and the like can be used in combination.

  Examples of the colorant blended to have the function required for the gravure printing ink of the present invention include organic and inorganic pigments and dyes used in general inks, paints, and recording agents. . Organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, isoindoline, etc. Pigments. Indigo ink is copper phthalocyanine, and transparent yellow ink is C.I. I. Pigment NoYellow83 is preferably used.

  Examples of the inorganic pigment include carbon black, titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, bengara, aluminum, mica (mica), and the like. From the viewpoints of cost and coloring power, it is preferable to use titanium oxide for white ink, carbon black for black ink, aluminum for silver ink, and mica for pearl ink. Aluminum is in the form of powder or paste, but is preferably used in the form of paste from the viewpoint of handling and safety, and whether to use leafing or non-leafing is appropriately selected from the viewpoint of brightness and concentration. When back printing is performed by a gravure printing method, black ink is often printed first, and it is said that beard and misting are likely to occur. The solvent-type gravure printing ink of the present invention exhibits an excellent effect with black ink, but there is no particular limitation on the hue.

  It is preferable that the colorant is contained in an amount sufficient to ensure the density and coloring power of the ink, that is, 1 to 50% of the total weight of the ink. Moreover, a coloring agent can be used individually or in combination of 2 or more types.

  In order to stably disperse the pigment in the organic solvent, it is possible to disperse the resin alone, but it is also possible to use a dispersant 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% or more based on the total weight of the ink from the viewpoint of the storage stability of the ink and 5% or less from the viewpoint of the suitability for lamination, and more preferably 0.1%. It is in the range of ~ 2%.

  The gravure printing ink of the present invention can be produced by dissolving and / or dispersing a resin, a colorant and the like in an organic solvent. Specifically, it is possible to produce a pigment dispersion in which a pigment is dispersed in an organic solvent with a polyurethane resin, and to produce an ink by blending the obtained pigment dispersion with other compounds as necessary. it can.

  The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the grinding media of the disperser, the filling rate of the grinding media, the dispersion treatment time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, and the like. be able to. 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 ink viscosity produced by the above method is in the range of 10 mPa · s or more from the viewpoint of preventing the pigment from settling and being appropriately dispersed, and 1000 mPa · s or less from the viewpoint of workability efficiency during ink production or printing. preferable. In addition, the said viscosity is a viscosity measured at 25 degreeC with the Tokimec B-type viscometer.

  The viscosity of the ink can be adjusted by appropriately selecting the type and amount of raw materials used, for example, resin, colorant, 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.

  As the organic solvent, the solvents used for the synthesis of the above-mentioned polyurethane resin can be used. Alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, and butanol, and ketone-based organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Solvents, ester organic solvents such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, aliphatic hydrocarbon organic solvents such as n-hexane, n-heptane, n-octane, and cyclohexane, methylcyclohexane, ethylcyclohexane, Examples include cycloaliphatic hydrocarbon organic solvents such as cycloheptane and cyclooctane, and aromatic hydrocarbon organic solvents such as toluene, and are used by mixing in consideration of the solubility and drying properties of the binder resin. It is preferable to do. The amount of these organic solvents used is 30% by weight or more in ordinary ink. In order to reduce printing defects due to static electricity of the present invention, it is preferable to select an organic solvent having a high polarity such as an alcohol-based organic solvent or a ketone-based organic solvent. The ink solvent composition at the time of printing is preferably 10 to 100% of the ketone organic solvent or the alcohol organic solvent or the total of both. More preferably, it is 25 to 100%.

As a method of containing a quaternary ammonium salt, there are a method of blending at the time of ink production, adding immediately before using the ink, or adding to a diluted ink after diluting to a viscosity suitable for printing with a diluent solvent. The content of the quaternary ammonium salt varies depending on whether the calculation is based on the ink (base ink) or the diluted ink. In the present invention, the content is calculated based on the ink (base ink).
When added to ink or diluted ink, it is desirable to dilute with an organic solvent such as alcohol or methyl ethyl ketone and add it as a 5-part diluted solution from the viewpoint of weighing accuracy.

The printing ink containing the solvent-type gravure printing ink of the present invention can be used for known printing methods such as flexographic printing in addition to gravure printing, and can be printed on adherends such as various plastic films. Specifically, examples of the printable plastic film include stretched and unstretched polyolefins such as polyethylene and polypropylene, polyester, nylon, cellophane, and vinylon.
In the case of gravure printing, it is diluted with a diluting solvent to a viscosity and concentration suitable for gravure printing, and is supplied to each printing unit alone or mixed.

  Furthermore, the usual extrusion lamination (extrusion laminating) method in which molten polyethylene resin is laminated on the printed surface of the printed material through various anchor coating agents such as imine, isocyanate, polybutadiene, and titanium, and urethane on the printed surface Laminate laminates can also be obtained by a known laminating process such as a dry laminating method in which an adhesive such as a coating is applied and a plastic film is laminated, or a direct laminating method in which a molten polypropylene is directly pressed and laminated on a printing surface. .

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples. The amine value is the number of mg of potassium hydroxide equivalent to hydrochloric acid required to neutralize the amino group contained in 1 g of resin. 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 using the titration amount A (mL) at this time.
Amine number = (A × f × 0.2 × 56.108) / S
The viscosity was measured at 25 ° C. with a Tokimec B-type viscometer.
The molecular weight was determined as a polystyrene-converted molecular weight by measuring the molecular weight distribution using a GPC (gel permeation chromatography) apparatus.

<Adjustment of polyurethane varnish>
[Synthesis Example 1]
229.4 parts of polyester diol (PPA2000) having a number average molecular weight (hereinafter referred to as Mn) of 2000 obtained from adipic acid and propylene glycol, 51 parts of isophorone diisocyanate and 200.0 parts of ethyl acetate were reacted at 85 ° C. for 4 hours under a nitrogen stream. 480.4 parts of a solvent solution of a terminal isocyanate prepolymer was obtained. Subsequently, 19.5 parts of isophoronediamine, 0.09 part of di-n-butylamine, 250.0 parts of ethyl acetate and 250.0 parts of isopropyl alcohol were mixed with a solvent solution 483.7 of the obtained terminal isocyanate prepolymer. Parts are gradually added at room temperature, and then reacted at 50 ° C. for 1 hour. A polyurethane resin having a solid content of 30%, a weight average molecular weight of 33,000, an amine value of 5.0 mgKOH / resin, and a viscosity of 400 mPa · s at 25 ° C. Varnish A) was obtained.

[Synthesis Example 2]
114.7 parts of PPA2000, 114.7 parts of polypropylene glycol (PPG2000) of Mn2000, 51.1 parts of isophorone diisocyanate and 125.0 parts of ethyl acetate were reacted at 85 ° C. for 4 hours under a nitrogen stream, and the solvent for the terminal isocyanate prepolymer 405.4 parts of solution were obtained. Next, 19.6 parts of isophoronediamine, 0.09 part of di-n-butylamine, 307 parts of ethyl acetate and 270 parts of isopropyl alcohol were mixed with 405.4 parts of the solvent solution of the obtained terminal isocyanate prepolymer at room temperature. Gradually added, then reacted at 50 ° C. for 1 hour, and a polyurethane resin (varnish B) having a solid content of 30%, a weight average molecular weight of 35000, an amine value of 6.0 mg KOH / resin, and a viscosity of 350 mPa · s at 25 ° C. Obtained.

<Preparation of vinyl chloride-vinyl acetate copolymer varnish>
[Adjustment Example 1]
24 parts of vinyl chloride-vinyl acetate copolymer (degree of polymerization 300, number average molecular weight 22000, Tg 76 ° C. [Solvine AL, manufactured by Nissin Chemical Industry Co., Ltd.]) were mixed and dissolved in 76 parts of ethyl acetate, and varnish C Got.

<Adjustment of polyamide varnish>
[Example of adjustment 2]
Varnish D was obtained by mixing and dissolving 30 parts of a polyamide resin having a softening point of 112 ° C. to 120 ° C. (Rheamide S-2800, manufactured by Kao Corporation) in 50 parts of methylcyclohexane and 20 parts of isopropyl alcohol.

<Adjustment of nitrocellulose varnish>
[Adjustment Example 3]
Varnish E was obtained by mixing and dissolving 20 parts of nitrocellulose (NC RS-2 KCNC, manufactured by KOREA CNC LTD) in 26 parts of ethyl acetate, 20 parts of isopropyl alcohol, and 34 parts of methylcyclohexane.

<Example 1>
40 parts of the obtained polyurethane resin (varnish A), 15 parts of vinyl chloride-vinyl acetate resin (varnish C), 10 parts of carbon black (Printex25, manufactured by Degussa), 10 parts of ethyl acetate, 15 parts of methyl ethyl ketone, 10 of isopropyl alcohol The mixture was kneaded, and after kneading, 1.1 parts of quaternary ammonium salt A (Cotamine 24P, active ingredient 27%, manufactured by Kao Corporation) was added to obtain ink 1.
Examples 2 to 5 and 7, Reference Example 6 and Comparative Examples 1 to 4 were prepared in the same manner as shown in Table 1 to obtain inks 2 to 11.

４級アンモニウム塩A：コータミン２４P、塩化ラウリルトリメチルアンモニウム、有効成分２７％、花王（株)製
４級アンモニウム塩B：サニゾールC、塩化アルキル（Ｃ１２〜１６）ベンジルジメチルアンモニウム、有効成分５０％、花王（株）製
４級アンモニウム塩C：コータミンＤ８６P、塩化ジステアリルジメチルアンモニウム、有効成分７５％、花王（株)製
４級アンモニウム塩Ｄ:エソガードC／１２、塩化アルキル（Ｃ８〜１８）ビス（２ヒドロキシエチル）メチルアンモニウム、有効成分７５％、ライオン（株）製
４級アンモニウム塩Ｅ：アーカード ２HT-５０ES、硫化ジ硬化牛脂アルキル（Ｃ１６〜１８）エチルメチルアンモニウム、有効成分５０％、ライオン(株)製
フタロシアニンブルー：リオノ−ルブル−ＫＬＨ 東洋インキ製造（株）製

Quaternary ammonium salt A: Cotamine 24P, lauryltrimethylammonium chloride, active ingredient 27%, quaternary ammonium salt B: Sanizol C, alkyl chloride (C12-16) benzyldimethylammonium chloride, active ingredient 50%, Kao Quaternary ammonium salt C: Cotamine D86P, distearyldimethylammonium chloride, active ingredient 75%, quaternary ammonium salt D: Esogard C / 12, alkyl chloride (C8-18) bis (2 Hydroxyethyl) methylammonium, 75% active ingredient, lion quaternary ammonium salt E: Arcard 2HT-50ES, di-cured beef tallow alkyl (C16-18) ethylmethylammonium, active ingredient 50%, Lion Corporation Phthalocyanine Blue: Lionol Blue-KLH Toyo Ink Manufacturing Co., Ltd. ) Made

For the inks obtained in Examples 1 to 5 and 7, Reference Example 6 and Comparative Examples 1 to 4, the following methods were used for the static electricity failure test, the time stability test, the substrate adhesion test, the blocking resistance test, and the boil. Suitability was evaluated. In order to adjust the inks 1 to 11 to the viscosity at the time of printing, using a mixed solvent consisting of 50 parts of toluene, 30 parts of ethyl acetate and 20 parts of isopropyl alcohol, the viscosity measured with Zaan Cup No. 3 at 25 ° C. is 16 seconds. Dilution inks 1 to 11 were obtained.

[Electrostatic failure test]
Using dilution ink 1-11, gravure printing machine equipped with gravure gradation plate (engraving in 5μm increments) with plate depth of 5μm to 45μm, inner corona discharge treatment with thickness of 20μm, no antistatic treatment, polypropylene film A printing film was obtained by continuously printing “ECO-BQ” (manufactured by Futamura Chemical Co., Ltd.) at a printing speed of 120 m / min and a dryer temperature of 40 ° C. to 50 ° C. for 30 seconds.
The state of occurrence of static electricity damage (whiskering and misting) in the 45 μm printing part of the obtained printing film was evaluated.
A: There is no occurrence of electrostatic failure. O: Almost no occurrence of electrostatic failure.
Δ: Slightly static failure occurred.
X: Electrostatic failure occurs remarkably.
The practical level is more than ○.

[Stability test over time]
The inks 1 to 11 were allowed to stand in a constant temperature room at 40 ° C. for 1 week, and then the stability was evaluated.
○: No thickening, precipitation, or separation is observed.
Δ: Slight thickening or slight precipitation or slight separation is observed.
X: Thickening or precipitation or separation is observed.
The practical level is Δ or more.

[Base material adhesion test]
Using dilution ink 1-11, gravure printing machine equipped with gravure gradation plate (engraving in 5 μm increments) with a plate depth of 5 μm to 45 μm, inner corona discharge treatment with a thickness of 20 μm, polypropylene film “Pyrene P2161” ( Toyobo Co., Ltd.) and vapor-deposited PET “GLARAH” (manufactured by Toppan Printing Co., Ltd.) were continuously printed at a printing speed of 40 m / min and a dryer temperature of 50 ° C. for 30 seconds to obtain a printing film.
Apply cellophane tape (Nichiban, width 12 mm) to the 35 μm portion of the printed matter and rub it strongly with the thumb five times. Then, gradually peel off the cellophane tape, and then suddenly pull it apart to check the degree of peeling of the ink film. It was. The state in which the ink was transferred to the cellophane tape was evaluated.
◯: The ink does not transfer 100% to the cellophane tape. Δ: The ink transfers about 10% to the cellophane tape portion that is abruptly separated, but the portion that is slowly peeled off does not transfer 100%.
X: The practical level at which the portion where the cellophane tape is stretched is transferred by 50% or more is Δ or more.

[Blocking resistance test]
Using dilution ink 1-11, gravure printing machine equipped with gravure gradation plate (engraving in 5 μm increments) with a plate depth of 5 μm to 45 μm, inner corona discharge treatment with a thickness of 20 μm, polypropylene film “Pyrene P2161” ( Toyobo Co., Ltd.) was continuously printed at a printing speed of 40 m / min and a dryer temperature of 50 ° C. for 30 seconds to obtain a printed film.
The untreated surface of the OPP film cut to the same size as the printed material and the printed surface are overlapped, applied with a load of 5 kg / cm ² , left in an atmosphere of 40 ° C. and 80% RH for 24 hours, and then the printed surface and the untreated OPP. The film was peeled off, and blocking resistance was evaluated from the degree of ink peeling.
○: The ink did not peel at all.
(Triangle | delta): The area where the ink peeled from the film is 20 to 50%.
X: The area where the ink peeled from the film exceeded 50%.
The practical level is more than ○.

[Boil aptitude]
Using diluted ink 1-11, with a gravure printing machine equipped with a gravure plate with a plate depth of 30 μm, with inner corona discharge treatment with a thickness of 15 μm, nylon film “Emblem ON-RT” (manufactured by Unitika Ltd.) Continuous printing was performed at a printing speed of 40 m / min and a dryer temperature of 50 ° C. for 30 seconds to obtain a printed film.
Polyurethane anchor coating agent “EL510, CAT-RT80” (manufactured by Toyo Morton Co., Ltd.) was applied to the obtained printed matter, and low density polyethylene (“Yukaron LK30” manufactured by Mitsubishi Yuka Co., Ltd.) and “ Extrusion laminating was performed with a “TUX-FCD” thickness of 40 μm to obtain a laminate. The nylon film laminate was aged at 40 ° C. for 2 days.
The obtained nylon film laminate was heat-sealed with the polyethylene film side inside, and the resulting bag was filled with water as the contents, and visually evaluated when boiled at 90 ° C. for 30 minutes. did.
○: No abnormality at all ×: Delamination or blister

As shown in Table 2, the inks of Examples 1 to 5 and 7 using monoalkyltrimethylammonium chloride, monoalkylbenzyldimethylammonium chloride, or dialkyldimethylammonium chloride as the quaternary ammonium salt were subjected to electrostatic damage (whisker, Misting) was good, and stability over time, adhesion to the substrate, blocking resistance and boil suitability were also good.

Claims (2)

The polyurethane resin as a main binder, a solvent-based gravure printing ink characterized by containing a quaternary ammonium salt shown by a general formula (I).

[However, R1 is an alkyl group having 8 to 22 carbon atoms, R2 and R3 are methyl groups, and R4 is an alkyl group having 1 to 18 carbon atoms or a benzyl group. ]
However, the solvent-type gravure printing ink contains a vinyl chloride-vinyl acetate copolymer as a combined resin binder. The solvent-type gravure printing ink according to claim 1, wherein 0.05 to 2.5 parts by weight of the quaternary ammonium salt is contained with respect to 100 parts by weight of the ink.