JP2007270025A - Printing ink composition and preparation process of printed matter using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition which has good printability and a good print effect so that when printing ink is printed upon another, the ink printed afterward shows good transferabilty to the printed ink film printed beforehand. <P>SOLUTION: This ink composition has good printability so that when printing ink is printed upon another especially for a gravure, the ink printed afterward shows good transferabilty to the printed ink film printed beforehand. This ink composition contains organic silicon as an essential component. A laminated item is obtained by lamination using printed matters to which good transferabilty is given by using this ink composition. A packed item and a package material are obtained by a process using this laminated item. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing ink, and more particularly, to a gravure ink composition that can reduce printing defects that occur during gravure ink printing, and a printed material in which the printing ink is applied to a known general raw material, and The present invention relates to a laminate obtained by laminating this printed matter through a general laminate adhesive, and a package and a packaging material processed using the laminate.

When printing ink is overprinted, the printing ink printed later on the previously printed ink film does not show good transferability and the phenomenon of poor color tone reproducibility (stains, scratches, reverse trapping, etc.) occurs Printing ink on the blank area (non-image area) that should not be transferred to the paper or film that is the substrate, because the doctor does not sufficiently scrape off the excess printing ink on the surface of the plate (gravure cylinder). The problem of printing defects called plate fogging (hereinafter referred to as plate fogging) occurs, and when printing ink is overprinted, the printing ink printed later dissolves on the previously printed printing ink film. As a result, there have been problems in cosmetics, such as color migration and poor color reproduction.
JP 2005-298618 A

  Conventionally, silica is added to the printing ink to be printed first to roughen the surface of the printed matter, making it easier to attach printing ink printed later, changing the printing conditions, for example, slowing the printing speed or changing the solvent drying speed, In some cases, a leveling agent was added to cope with this, but silica decreased gloss and adhesion, changes in the drying speed of the solvent affected blocking and odor, and commercially available leveling agents It was a situation where we could not find any effective products.

The object of the present invention is that when printing ink is overprinted, the printing ink printed later on the previously printed printing ink film does not show good transferability, the phenomenon of poor color tone reproducibility, and gravure printing An object of the present invention is to provide a printing ink composition containing an organosilicon compound represented by the following <Chemical Formula 1>, which solves the printing suitability of the above-described plate fogging.

As a result of intensive studies in view of the above situation, the inventors of the present invention have a color tone reproducibility superior to that of conventional printing inks, in which a printing ink containing an organosilicon compound represented by the following <Chemical Formula 1> The present invention has been found out to have printability (plate fog, etc.).

<Chemical formula 1> R3
｜
_{(CH 3) 3 Si-O-} (Si (CH 3) -O) N - (Si-O) M Si (CH 3) 3
｜ ｜
R1 R2

Formula N and M in <Chemical Formula 1> are integers greater than or equal to 1 R1 is a methyl group, aralkyl group, phenyl group R2 is a methyl group, phenyl group, aralkyl group R3 is a methyl group, alkyl group, phenyl group

The present invention is characterized in that it contains an organosilicon compound represented by <Chemical Formula 1>, and with respect to 100 parts by weight of printing ink,
The present invention relates to a printing ink in which the content of the organosilicon compound represented by <Chemical Formula 1> is 0.01 to 1 part by weight.
The organosilicon compound of <Chemical Formula 1> is preferably methylphenylsiloxane, and among printing inks, it relates to use in gravure inks, particularly oil-based gravure inks.
The present invention relates to a printed material printed with this printing ink and a laminate obtained by laminating, and further to a packaging material obtained by processing this laminate.

By using the compound represented by <Chemical Formula 1>, the printing ink of the present invention improves the color tone reproducibility of the currently printed printing ink and the printability such as plate fog, reduces the defective product rate, and improves the cosmetic properties. An improvement can be provided.

  As a method for incorporating the compound represented by <Chemical Formula 1> into the printing ink of the present invention, it is blended at the time of ink production, added immediately before using the printing ink, or diluted to a viscosity suitable for printing with a diluent solvent. There are methods such as adding to later diluted ink. The value of this compound varies depending on whether the calculation is based on raw ink (base ink) or diluted ink. In the present invention, the content is calculated based on raw ink (base ink).

The printing ink of the present invention can be printed by a printing method according to the use such as polyolefin, polyester, nylon, coated paper, etc., and can be applied to all printing methods such as gravure printing, flexo, intaglio, etc. Can do.

  The printed matter obtained by printing the printing ink of the present invention can be a laminate in which polyolefin, polyester, aluminum or the like is laminated via a general laminate adhesive. These laminates can be widely used as a base material for packaging foods and pharmaceuticals.

Examples of the colorant 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. From the viewpoint of cost and light resistance, it is preferable to use C. I. Pigment No Yellow 83 for the indigo ink and copper phthalocyanine for the transparent yellow ink.

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. Further, a luster pigment (Metashine; Nippon Sheet Glass Co., Ltd.) having glass or block flake as a base material and coated with metal or metal oxide can be used. 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.
The colorant is preferably contained in an amount sufficient to ensure the density and coloring power of the printing ink, that is, in a proportion of 1 to 50% by weight based on the total weight of the printing ink. Moreover, a coloring agent can be used individually or in combination of 2 or more types.

Furthermore, since it has a function required as printing ink, it can contain a combination resin, an organic solvent, and the like. In addition, extender pigments, pigment dispersants, leveling agents, antifoaming agents, waxes, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, and the like can be included as necessary.

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 printing ink in an amount of 0.05% by weight or more and 5% by weight or less based on the total weight from the viewpoint of storage stability of the printing ink, more preferably 0.1 to 2% by weight. % Range.

  Examples of the resin used in the printing ink of the present invention include water-based shellac, rosin-modified maleic acid resin, styrene- (meth) acrylic acid copolymer resin, (meth) acrylic acid ester- (meth) acrylic acid copolymer. Resin, water-based polyester resin, water-based polyurethane resin, etc. are used, and oil-based polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, 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 acid resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin and the like. These resins can be used alone or in admixture of two or more, and the holding amount is preferably 5 to 25% by weight with respect to the total weight of the printing ink.

The printing ink of the present invention can be produced by dissolving and / or dispersing a resin, a colorant or the like in an organic solvent or water. Specifically, a printing ink can be produced by producing a pigment dispersion in which a pigment is dispersed with a resin, and blending the obtained pigment dispersion with other compounds as required.

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 a 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. When bubbles or unexpectedly large particles are included in the printing 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 printing 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 dispersing appropriately, and 1000 mPa · s or less from the viewpoint of workability efficiency during ink production or printing. Is preferred. In addition, the said viscosity is a viscosity measured at 25 degreeC with the Tokimec B-type viscometer. The viscosity of the printing ink can be adjusted by appropriately selecting the type and amount of raw materials used, for example, resin, colorant, organic solvent, and the like. Moreover, the viscosity of printing ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in printing ink.

As the hue of the printing ink of the present invention, there are five basic colors of yellow, red, indigo, black, and white depending on the type of colorant used, and red (orange), grass as the process gamut external color There are three colors (green) and purple. Further, transparent yellow, peony, vermilion, brown, gold, silver, pearl, almost transparent medium for adjusting color density (including extender pigments if necessary), etc. are prepared as base colors. The boil retort ink is appropriately selected in consideration of pigment migration and heat resistance. The base ink of each hue 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.

The organosilicon compound represented by <Chemical Formula 1> is synthesized by an existing synthesis method, and the following synthesis method is described as an example.
Into a 500 ml flask equipped with a stirrer, 248 g of distilled water was added and the temperature was raised to 50 ° C. with stirring. A mixture of 76.9 g of methylphenyldichlorosilane and 43.4 g of chlorotrimethylsilane (0.4 mol each) had a reaction temperature of 50. The dropping speed is controlled so as to be ˜80 ° C. After stirring for 30 minutes, the organic layer was separated and returned to the flask again, 200 g of 4% aqueous sodium hydrogen carbonate solution was added to the organic layer, and the mixture was heated and stirred at 90 ° C. for 1 hour to separate the organic layer. Then, it is washed with water and dried with anhydrous sodium sulfate to obtain a compound presumed to be methylphenylsiloxane. (Reference Patent 2000-7786)

  The compounds represented by <Chemical Formula 1> of the present invention fall under the category of products such as GE Toshiba Silicone, Shin-Etsu Chemical, Byk-Chemie GmbH.

The present invention will be described more specifically with reference to examples. Hereinafter, both “parts” and “%” are based on weight.
In addition, a hydroxyl group is the number of mg of potassium hydroxide required in order to neutralize the hydroxyl group contained in 1g of resin, and is the value performed according to JISK0070. 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 was as described below. The molecular weight was determined as a polystyrene-converted molecular weight by measuring the molecular weight distribution using a GPC (gel permeation chromatography) apparatus. The viscosity was measured at 25 ° C. with a Tokimec B-type viscometer.

(Example of resin composition for printing ink)
147.1 parts of polyester diol (PMPA4000) having a number average molecular weight (hereinafter referred to as Mn) of 4,000 obtained from adipic acid and 3-methyl-1,5-pentadiol, 97.0 parts of polypropylene glycol (PPG2000) of Mn2000, 39.7 parts of isophorone diisocyanate and acetic acid 90 parts of ethyl was reacted at 90 ° C. for 6 hours under a nitrogen stream to obtain 373.8 parts of a solvent solution of a terminal isocyanate prepolymer. Next, 15.8 parts of isophoronediamine, 0.3 part of 2-hydroxyethylethylenediamine, 0.1 part of di-n-butylamine, 330 parts of ethyl acetate and 280 parts of isopropyl alcohol were mixed with 473 parts of the solvent solution of the resulting terminal isocyanate prepolymer. Gradually added at room temperature, and then reacted at 50 ° C. for 1 hour to obtain a polyurethane resin solution A having a solid content of 30%, an amine value of 1.0 mg KOH / resin, 1 g of hydroxyl value, 0.2 mg KOH / resin of 1 g, and a viscosity of 8 P at 25 ° C. It was.

[Example]
Indigo ink is a mixture of 12 parts of copper phthalocyanine indigo, 40 parts of polyurethane resin solution A, 42 parts of methyl ethyl ketone, 6 parts of isopropyl alcohol, and red ink is 12 parts of soluble azo (CIPIGUMENNT RED57: 1), 40 parts of polyurethane resin solution A. Knead a mixture of 42 parts of methyl ethyl ketone and 6 parts of isopropyl alcohol, white ink 30 parts of titanium oxide white, 50 parts of polyurethane resin solution A, 14 parts of methyl ethyl ketone, and 6 parts of isopropyl alcohol. A gravure ink (base ink) was obtained.

  To each 100 parts of the base ink, 0.015 part, 0.03 part, 0.05 part, and 0.8 part of methylphenylsiloxane (GE Toshiba Silicone Methylphenylsilicone TSF431) are added to increase the viscosity during printing. To adjust, diluted with a mixed solvent consisting of 20% isopropyl alcohol, 40% propyl acetate and 40% ethyl acetate at 25 ° C. so that the viscosity measured with Zahn Cup No. 3 is 15 seconds. Indigo and white gravure inks (diluted inks) were obtained. Similarly, 0.03 part of dimethylsiloxane (dimethylsilicone TSF451-100 manufactured by GE Toshiba Silicones) was added to obtain a diluted ink.

Comparative example

  The non-toluene type urethane ink (without methylphenylsiloxane) was used as a comparative example. Furthermore, what added 1.5% methylphenylsiloxane was described as a reference example.

The printing conditions were a doctor blade with a cutting edge thickness of 65 μm, “New Doctor High Blade” (manufactured by Fuji Shoko Co., Ltd., hereinafter abbreviated as “doctor blade”), doctor pressure 2 kgf / cm ² , impression pressure 2 kg / Cm ² ,
Printing speed 150 m / min, drying conditions are temperature 60 ° C., air volume 45 m ³ / min, base material is OPP (thickness 20 μm, P2161 manufactured by Toyobo), printing press is gravure rotary printing machine (manufactured by Fuji Machine Industry Co., Ltd.) Printed.

The evaluation of color tone reproducibility was confirmed by trapping and dot gain.
Trapping: A visual judgment was made as to whether or not the overlapping portion of the printing ink in the% portion of each plate could be clearly confirmed in the gradation plate.
Dot gain: The dot gains of the solid white area and the overlapping area of red and indigo on the halftone dot area 50% of the indigo and red printing plates were visually determined.
Plate fogging property: The printed matter was pasted on black paper, and the amount of printing ink adhered to a blank portion (non-image portion) was visually evaluated.
Defoaming property: 100 g of an aqueous anti-slip agent composition was put in a glass container, stirred with a hand mixer at 3000 rpm for 5 minutes, and the height of the resulting foam and the degree of defoaming after stopping were measured.
○: Bubbles of 1cm or less occur and disappear within 1 minute.
○ △: Bubbles of 1 to 3 cm are formed and disappear within 1 minute.
Δ: Bubbles of 3 to 5 cm are formed and within 1 cm within 1 minute.
Δ ×: Bubbles of 3 to 5 cm are formed and within 1 cm within 5 minutes.
X: Bubbles of 5 cm or more are generated and do not disappear in 5 minutes.
Color transfer: Color ink is applied to a surface-treated polypropylene film (OPP) with a bar coder so as to have a thickness of 2 to 3 μm in solid content, dried at 60 ° C. for 10 seconds, and then white ink is added on the solid content to 2 It was applied with a bar coder so as to have a thickness of ˜3 μm, and it was observed that the indigo ink of the base ink was eluted and mixed with the white ink.
○: Indigo ink in the base ink is not mixed. Δ: Indigo ink in the base ink is slightly mixed. ×: Indigo ink in the base ink is mixed.

[Lamination method]
A gravure rotary printing press equipped with a gravure plate with a plate depth of 35 μm, printing on the corona discharge treated surface of a 15 μm thick corona discharge treated nylon film “Emblem” (trade name, hereinafter abbreviated as NY). The film was printed at a speed of 100 m / min and dried at 40 to 50 ° C. to obtain a film on which the printing ink of the present invention was printed (hereinafter abbreviated as a printing film).
Further, polyisocyanate anchor coating agent “EL-510 and CAT-RT80” (trade name, manufactured by Toyo Morton Co., Ltd.) was applied to the printing surface of the almost printed film, and low density polyethylene “Novatech LC606” was used as a sealant on the coated surface. The melt temperature of “Nippon Polychem Co., Ltd., trade name” was extruded at 315 ° C. to obtain a laminated product at each temperature. The melting temperature of the low density polyethylene was measured by a contact thermometer (HL-100 manufactured by Anritsu Keiki Co., Ltd.) at a temperature immediately below the T die of the extrusion laminating machine. The laminating strength of the ink part in the roughly laminated product was measured.
[Measurement of laminate strength]
The laminate was cut at a width of 15 mm and peeled between the ink surface and the molten resin layer, and the peel strength was measured with an Intesco 2010 universal tensile tester.

Table 1 Test results

Compared to the examples, the comparative examples are inferior in trapping properties and halftone dot solubility, and inferior in the appearance of the overlapping printing ink,
In the examples, the trapping was good, and the printing ink in the overlapping portion was clearly transferred, and the printed matter was good.
The amount of addition of methylphenylsiloxane is equivalent to the trapping property at the addition amount of 0.03% or more, but the foam and laminate strength are slightly inferior at the addition amount of 0.08% or more, and the addition amount of methylphenylsiloxane is 0.015% to 0.05% is preferable. The laminate strength is desirably 5.0 N / 15 mm width or more. Although the dimethylsiloxane of Example 5 improved the printing effect, it was not as effective as methylphenylsiloxane.
The resin and solvent composition of this system is preferably 0.03% or more, and if it is 1% or more, it is difficult to use it for laminating ink due to the relationship between foam and laminate strength. About 1% can be used by reducing the number (such as a stirring bar) or changing the solvent composition.

Claims (6)

A printing ink comprising a compound represented by <Chemical Formula 1>. The printing ink according to claim 1, comprising 0.01 to 1 wt% of a compound represented by <Chemical Formula 1>. The printing ink according to claim 1 or 2, wherein the compound represented by <Chemical Formula 1> is methylphenylsiloxane. 4. The printing ink according to claim 1, which is an oil gravure ink. The printed matter formed by printing using the printing ink in any one of Claims 1-4. A package and a packaging material obtained by laminating and processing the printed matter according to claim 5.