JP2006016484A - Printing ink composition and laminated article using the ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing ink composition printed on plastic film, etc., for providing an ink film having a good sliding property, a laminated article printed with the printing ink on its film and further a film label consisting of the laminated article. <P>SOLUTION: This printing ink composition containing 0.1-10 mass % spherical cured resin particles and/or spherical cross-linked type resin fine particles based on the total ink composition, and the laminated article or a film label printed with the printing ink on its film are provided. As the curable resin fine particles, it is possible to use fine particles consisting of a benzoguanamine resin, melamine resin or formaldehyde condensate. As the cross-linked type fine particles, acrylic cross-linked type resin fine particles and polymethyl methacrylate-based cross-linking type resin fine particles can be used. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing ink composition printed on a plastic film, the printing surface of which has a good slip property, and a laminate using the ink. Moreover, it is related with the film label using the laminated body.

  In recent years, containers of various forms have come to be used in food and drinks due to diversification of consumer preferences. For example, glass bottles and plastic bottles used for beverages and the like also use a wide variety of containers. In order to impart design and information properties to these containers, film labels on which pictures and characters are printed may be attached.

  One of the performances required when the film label is attached to a container such as a bottle is the slipperiness of the label. If slipping is bad, troubles such as wrinkles and tearing will occur when attaching to bottles. This slipping property is greatly influenced by the slipping property of the ink film printed on the film, and in order to obtain excellent mounting suitability, it is desired to develop a printing ink having excellent slipping property.

  Conventionally, as a method for imparting slipperiness to an ink film printed on a film label or the like, a method of adding polyethylene wax, fluorine wax, silicon dioxide powder or the like to the printing ink is known.

  Patent Document 1 describes an ink composition for lithographic printing containing 0.1 to 5% by mass of amorphous polytetrafluoroethylene wax particles having an average particle diameter of 2 to 4 μm in the total ink composition. . The wax particles used are irregular in shape, and paragraph 6 describes that the particles protrude on the ink film to improve the rubbing resistance, and the wax particles function to impart slipperiness. It seems not.

  Patent Document 2 describes a method of forming a hard and flexible coating film using a coating agent containing crosslinked elastic resin fine particles of 5 μm or less as an essential component of a film-forming resin. Examples of the crosslinkable elastic resin fine particles used therefor include vinyl type, urethane type and urethane urea type. Paragraph 13 describes that the resin fine particles are soft and elastic to absorb external force and give the film hardness and flexibility, and the resin fine particles do not impart slipperiness to the film. I think that the.

  Patent Document 3 describes a cylindrical shrink label that can be smoothly attached to a container such as a bottle whose surface is wet. This document states that the suitability of the white ink layer on the inner surface of the label is improved by setting the wetting index to 34 or less and the dynamic friction coefficient to 0.6 or less. However, according to paragraph 18 of the document, there is an explanation that the value of the wetting index or the like is adjusted by changing the kind or content of the pigment in the ink or the silicone, but a specific method for obtaining these values And the blending amount is not described. The pigment concentration and type are determined to some extent depending on the design, and there is little room for selection and adjustment for slipperiness, and even a small amount of silicone has a large effect on the overall ink characteristics, so there is little room for adjustment. Therefore, it is considered that it is practically difficult to adjust the slipperiness by selecting pigments and silicones and adjusting their blending amounts.

Japanese Patent Laid-Open No. 8-113748 JP-A-5-132636 JP-A-10-309771

  The present invention provides a printing ink composition printed on a plastic film or the like, the ink film having a good slip property, and a laminate obtained by printing the printing ink on a film, Furthermore, it aims at providing the film label which consists of the laminated body.

  As a result of intensive studies, the present inventors have printed on a film using a printing ink composition containing 0.1 to 10% by mass of spherical curable resin particles and / or spherical crosslinked resin particles in the total ink composition. By doing so, it was found that the ink film had a good slip property, and the present invention was completed.

  In the present invention, fine particles comprising benzoguanamine resin, melamine resin or formaldehyde condensate can be used as the curable resin fine particles, and these resin raw materials may be mixed. As the cross-linked resin fine particles, acrylic cross-linked resin fine particles can be used, and polymethyl methacrylate-based cross-linked resin fine particles are more preferable.

  The average particle diameter of these resin fine particles is preferably 0.1 to 20 μm. The average particle diameter in the present invention is a volume average particle diameter obtained by a laser diffraction method, a Coulter counter method, or the like.

The dry coating amount of the printed / applied printing ink is preferably 0.3 to 2.0 g / m ² . As a printing / printing method of the printing ink in the present invention, an arbitrary method such as general gravure printing, flexographic printing, silk screen printing or the like is used, but gravure printing is preferably used.

  In the film printed with the printing ink in the present invention, the ink film has excellent slipperiness. By using this printed film as a film label or the like, it is possible to obtain excellent mounting suitability that does not easily cause wrinkles or tears when mounted on containers such as glass bottles and plastic bottles.

  The printing ink composition of the present invention preferably contains 0.1 to 10% by mass of spherical curable resin fine particles and / or cross-linked resin fine particles in the total ink composition. If the content is higher than this, the fluidity of the ink deteriorates and printing becomes difficult. If it is lower than this, sufficient slipperiness cannot be obtained. More preferably, it is 0.1-5.0 mass% as content, More preferably, it is 0.1-2.0 mass%. The reason for this is to obtain an ink having good printability with little occurrence of doctor stripes peculiar to gravure printing and no impression cylinder stains.

  The spherical shape is preferably closer to a true sphere, but in order to achieve the effect of the present invention, the resin is visually observed with a microscope or the like, and there is no pointed portion or the like, and it is not a flat shape or a prismatic shape. Thus, it is only necessary that the ratio of the minimum diameter to the maximum diameter of the sphere is recognized to be approximately 1: 1.2 or less when a sphere shape is applied to the resin. It is more preferable if it is 1: 1.1 or less.

  An example of a method for determining the quality of the fine particle shape will be described with reference to FIG. 1. Reference numeral 1 in FIG. 1 represents the external shape of the fine particle when observed with a microscope or the like. Of the circles fitted so as to be in contact with the outer shape of the fine particles, the circle with the largest diameter is circle 2 and the circle with the smallest diameter is circle 3. When the diameter of the circle 3 is 100, the diameter of the circle 2 may be 120 or less, and more preferably 110 or less.

As the curable resin fine particles, fine particles of benzoguanamine resin or melamine resin can be used. An acrylic resin can be used as the crosslinked resin fine particles. These resin fine particles may be used alone or in combination.

  Conventionally used fine particle additives include inorganic fine particles such as magnesium carbonate and silicon dioxide. However, since the shape is not constant, it is difficult to obtain stable slipperiness, which is not suitable for the present invention.

  The diameter of the spherical resin fine particles is preferably 1 to 20 μm. More preferably, it is 3-15 micrometers. This is to improve printing suitability such as plate surface fogging and transferability peculiar to gravure printing, and to obtain sufficient slipperiness.

  The vehicle of the printing ink composition of the present invention may use a resin generally used for printing ink. For example, polyolefin resin, polyamide resin, ketone resin, fibrous resin, acrylic resin, urethane resin, vinyl acetate resin, vinyl chloride resin, melamine resin, urea resin, epoxy resin, shellac, alkyd resin, rosin modified maleine Acid resin and the like.

  In the printing ink composition of the present invention, various additives used in conventional printing inks may be used as necessary. Examples include colorants such as organic pigments and inorganic pigments, dyes, waxes, plasticizers, leveling agents, surfactants, dispersants, antifoaming agents, chelating agents, and the like.

  Moreover, you may use the various solvent used for the conventional printing ink etc. also for the solvent used for the printing ink composition of this invention. Examples include aromatic hydrocarbons such as toluene and xylene, aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane, esters such as ethyl acetate and propyl acetate, alcohols such as methanol, ethanol and isopropyl alcohol. And ketones such as acetone and methyl ethyl ketone.

(Regarding claim 4)
The dry coating amount of the ink printed on the plastic film is preferably 0.3 to 2.0 g / m ² . Above this, the adhesion between the ink and the film is lowered, and below this, sufficient slipperiness cannot be obtained.

  Although the said plastic film can use a general film as a printing material, when using for a film label, heat shrink films, such as a polystyrene, a polyethylene terephthalate, and polyolefin, are used more preferably.

  In the present invention, the slipperiness of the film can be utilized by printing the printing ink of the present invention on the innermost surface (side in contact with the bottle) of the film. Of course, the above printing ink may be used alone to print on the film, or the white ink and / or the pattern ink and the ink of the present invention may be laminated on the plastic film. For example, yellow, red, indigo and black process color inks are used as the pattern ink.

Hereinafter, the present invention will be described by way of examples. Parts or% in the text is based on mass.
[Fine particles used in Examples and Comparative Examples]
Fine particles A in Example 1 “Eposter (registered trademark) L15” manufactured by Nippon Shokubai Co., Ltd. The particle diameter is 15 μm, and the material is a benzoguanamine / formaldehyde condensation resin.
Fine particles B in Example 2 “Eposter (registered trademark) MA 1013” manufactured by Nippon Shokubai Co., Ltd. The particle diameter is 15 μm, and the material is a polymethyl methacrylate-based crosslinked resin.
Fine particles C of Comparative Example 1 “Eposter (registered trademark) MX” manufactured by Nippon Shokubai Co., Ltd. The primary particle diameter is 0.01 μm, and the material is a polymethyl methacrylate-based crosslinked product.
Fine particles D of Comparative Example 2 “Silicia (registered trademark) 470” manufactured by Fuji Silysia Chemical Ltd. The particle diameter is 15 μm and the material is silicon dioxide.

[Preparation of printing ink]
After mixing 40 parts of "Acridic (registered trademark) WCL-476" manufactured by Dainippon Ink & Chemicals, Inc., 30 parts of isopropyl alcohol, and 23 parts of ethyl acetate with stirring and dissolving, the above fine particles (A to D) 2 parts), 5 parts of polyethylene wax (manufactured by Dainippon Ink & Chemicals, Inc., “NC-6 Polycon”, particle size 5 μm) are added and mixed with stirring. Example 2 and Comparative Example 2 shown in Table 1 A point gravure printing ink was prepared.

[Production of laminate]
After adjusting the viscosity by diluting the above gravure printing ink with a solvent, it is dried to a polystyrene film ("GMG" manufactured by Gunze Co., Ltd.) with "DICOM PROFER DP-III" auto-proofer manufactured by Dainippon Ink & Chemicals, Inc. The color was developed so that the coating amount was 0.5 g / m ² .

[Evaluation of slipperiness]
Using the “friction measuring machine TP-2” (Toyo Seiki Seisakusho Co., Ltd.), the printed film is rubbed with the printing ink surface and the PET sheet surface as the measurement surface, and the slip coefficient is measured. did. Note that the lower the friction coefficient, the better the slipperiness. For film labels, both the dynamic friction coefficient and the static friction coefficient are preferably 0.30 or less.

  From Table 1, it can be seen that the ink films of Examples 1 and 2 are excellent in slipperiness.

  The printing ink of the present invention and those printed on a plastic film can be suitably used as a film label to be mounted on a container such as a glass bottle or a plastic bottle because the ink film has good slipperiness.

An example of a method for determining the degree of sphericalness from a microscope image is shown.

Explanation of symbols

1 External shape of resin fine particle 2 Maximum circle fitted to the external shape of resin fine particle 3 Smallest circle fitted to the external shape of resin fine particle

Claims (6)

A printing ink composition containing 0.1 to 10% by mass of spherical curable resin fine particles and / or spherical cross-linked resin fine particles in the total ink composition. The printing ink composition according to claim 1, wherein the resin of the resin fine particles is at least one selected from the group consisting of a benzoguanamine resin, a melamine resin, and an acrylic resin. The printing ink composition according to claim 1, wherein the resin fine particles have a diameter of 1 to 20 μm. The printing ink according to claim 1 comprising one printed on a plastic film, laminate dry coating amount of the printing ink is 0.3 to 2.0 g / m ^2. The laminated body which laminated | stacked the layer of the printing ink of Claim 1 on the plastic film. The film label for bottles which consists of a laminated body of Claim 5.

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