JP2005281371A - Electron beam-curable overprint varnish and product coated therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron beam-curable overprint varnish for ensuring the matte feeling of a base such as for packaging materials and printed surface thereof not to be lost due to smoothing by impact or the like, and to provide a product coated with the varnish. <P>SOLUTION: The electron beam-curable overprint varnish contains an electron beam-curable ingredient and is characterized by also containing carnauba wax. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention has good adhesion to a substrate, for example, a packaging material substrate and a printed surface thereon, and has characteristics such as scratch resistance, weather resistance, chemical resistance, and the like. The present invention relates to an electron beam curable overprint varnish characterized in that a matte feeling is not lost by smoothing by friction and impact, and a coated product thereof.

Conventionally, in printing of a base material, for example, a base material for packaging material, in order to give a matte feeling, the matte feeling, resistance, strength, etc. are good. Many are coated with mat overprint varnish.
However, the matte film paste is disadvantageous in that the cost is high because an expensive matte film is used, and the productivity is low because the laminate process is performed (see Patent Document 1). In addition, when the UV curable mat overprint varnish is applied, the matte feeling is lost due to friction and impact due to low surface drying and low surface hardness.
JP 2003-62954 A

  Electron beam curable overprint varnish and its coating to obtain a base material, for example, a packaging material base material and a matte surface of the printed surface that is smoothed by friction, impact, etc. so as not to lose the mat feeling Offer things.

In order to solve the above problems, a carnauba wax excellent in hardness is contained, and an electron beam curable overprint varnish excellent in coating surface hardness is used. It was discovered that the matte feeling on the printed surface was smoothed by friction and impact, so that a coated product in which the matte feeling was not lost could be obtained.
That is, the first invention is an electron beam curable overprint varnish containing a component that is cured with an electron beam, and containing carnauba wax.
A second invention is an electron beam curable overprint varnish containing an electron beam curable component, wherein carnauba wax is contained in the varnish in a solid content of 10% by weight or less. It is.
According to a third invention, the electron beam curable overprint varnish of the first or second invention further contains at least one selected from polytetrafluoroethylene, polyethylene, and lanolin. Overprint varnish.
In a fourth invention, the electron beam curable overprint varnish of any one of the first to third inventions is applied to a substrate which may have a printed layer, and cured by irradiation with an electron beam. It is a coated product characterized by this.
In the present invention, curing includes cases such as crosslinking.

In the present invention, an electron beam curable overprint varnish containing carnauba wax having excellent hardness is applied onto a substrate, for example, a packaging material substrate and its printed surface, and cured using an electron beam irradiation apparatus. Thus, it is possible to provide a coated product having excellent permanent matte feeling and properties such as drying property, adhesion property, and scratch resistance, and a method for producing the same.

Hereinafter, embodiments of the present invention will be described in detail.
As a component cured with an electron beam which is a main component of the electron beam curable overprint varnish according to the present invention, a radical polymerization monomer is usually used, and a bifunctional compound having an α, β-unsaturated double bond in the molecule. The above-mentioned monomers and / or monofunctional monomers, vinyl-type monomers, allyl-type monomers, acrylate-type or methacrylate-type (hereinafter referred to as (meth) acrylate-type) monomers, and the like can be mentioned, It will not specifically limit if a cured film is formed by the curing reaction by irradiation. The (meth) acrylate type monomer may have a functional group other than the α, β-unsaturated double bond. In addition, the radical polymerization monomer may be used alone or in combination of two or more monomers in order to adjust the crosslinking density.

The term “monomer” as used herein refers to an oligomer or prepolymer having a relatively low molecular weight, for example, a so-called narrowly-defined monomer having a weight average molecular weight of less than 1000, as well as a molecular weight that is somewhat high, for example, a weight average molecular weight of 1,000 to 10,000. Examples of oligomers having an α, β-unsaturated double bond include polyester (meth) acrylate, polyurethane (meth) acrylate, epoxy (meth) acrylate, (meth) acrylated maleic acid-modified polybutadiene Etc.
Examples of vinyl monomers include styrene, α-methylstyrene, divinylbenzene, N-vinyl pyrrolidone, vinyl acetate, N-vinyl formaldehyde, N-vinyl caprolactam, and alkyl vinyl ether. Examples of allyl monomers include trimethacryl isocyanurate, And triallyl cyanurate.

  The monofunctional (meth) acrylate monomer is used for the purpose of adjusting the viscosity of the composition, the improvement of adhesion to the substrate or its printed surface, and the like. Specifically, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, isooctyl (meth) acrylate, 2-hydroxyethyl acrylate, cyclohexyl acrylate, nonylphenyl acrylate, tetrahydrofurfuryl acrylate, and methacrylates, derivatives thereof, Examples include modified products.

  The polyfunctional (meth) acrylate monomer is used for the purpose of improving curability and obtaining physical properties such as hardness. Specifically, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, ditrimethylolpropane tetraacrylate, trimethylolpropane triacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol Examples include diacrylate, polyethylene glycol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, and methacrylates, derivatives, and modified products thereof.

  By making the composition of the electron beam curable overprint varnish mainly composed of the electron beam curable (meth) acrylate having the (meth) acryloyl group as described above, a substrate, for example, a substrate for packaging material and Adhesion with the printed surface is improved, and scratch resistance, weather resistance, chemical resistance and the like of the resulting cured film are improved.

  In addition to the above-mentioned radical polymerization monomers, non-crosslinkable resins such as acrylic resins and polyurethane resins, and cationic polymerization monomers such as epoxy resins, vinyl ether compounds, oxetane compounds and the like can be blended as required. It is effective in improving the properties and adhesion to the substrate.

  Also, paint additives such as leveling agents, antifoaming agents, antiblocking agents, adhesion aids, dispersants, drying regulators, antifriction agents, ultraviolet absorbers, slipping improvers, trapping improvers, etc. Can do. For example, silicon-based and fluorine-based additives that impart leveling, surface slip properties, and the like are effective in preventing scratches on the cured film surface. Inorganic material additives such as zinc oxide, titanium oxide, and silicon oxide can have various optical properties such as antireflection and ultraviolet absorption.

  For the purpose of securing an appropriate viscosity at the time of coating, dispersion, etc., a solvent may be contained within a range that does not affect the substrate in the drying step. Solvents include ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ester compounds such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, and methoxyethyl acetate, and ether compounds such as diethyl ether and ethylene glycol dimethyl ether. Compounds, aromatic compounds such as toluene and xylene, aliphatic compounds such as pentane and hexane, halogenated hydrocarbon compounds such as methylene chloride, chlorobenzene and chloroform, alcohols such as ethanol, isopropyl alcohol and normal butanol, and water It is done. These solvents may be used alone or in combination of two or more.

  Carnauba wax is used as a matting agent that gives a matte feel to the surface. As the carnauba wax, a dispersed one may be used, and one dispersed in the above-mentioned ones such as radical polymerization monomers and solvents can be used. The content of carnauba wax in the electron beam curable overprint varnish is preferably 10% by weight or less, more preferably 0.01 to 5% by weight. If it is 0.01% by weight or less, a sufficient matte feeling may not be obtained, and if it is 10% by weight or more, the curability of the coating film may be deteriorated and various physical properties may not be obtained.

  In addition to carnauba wax, polytetrafluoroethylene, polyethylene, or lanolin can be further used to impart surface slipperiness and scratch resistance. It may be dispersed with a radical polymerization monomer or solvent. Liquid wax can also be used. These waxes may be used alone or in combination of two or more. Moreover, the addition amount is 0.01 to 10 weight% normally by solid content in this varnish.

The coated product basically has a structure in which an electron beam curable overprint varnish layer is formed on at least one surface of a substrate, for example, a packaging material substrate.
The substrate can be appropriately selected from known substrates.
Specifically, polyethylene film, polypropylene film, polyester film, polyvinyl chloride film, cellophane, nylon film, polyvinyl alcohol film, polycarbonate film, polyvinylidene chloride film, polyacetate film, polystyrene film, acrylic film, heat resistance -Engineering plastic film, fluororesin film, art paper, top coat paper and the like. These substrates may be a single layer or may be multi-layered by lamination. The film substrate may be a transparent film or colored with a pigment and / or a dye. In addition, those that have been primed with a polyester resin or the like, or those that have been subjected to a surface treatment such as corona treatment may be used.

  The printing on the substrate is not particularly limited, and a printing layer may be provided by offset printing, gravure printing, flexographic printing, screen printing, or the like.

  The method of applying the electron beam curable overprint varnish to the substrate is not particularly limited, but practically, a flexo coater, a die coater, a curtain flow coater, a roll coater, a reverse roll coater, and a gravure coater. Coating with a knife coater, bar coater or the like is common. The coating may be performed by any process such as an off-line process separate from printing and an on-line process performed simultaneously with printing.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. Parts and% are based on weight unless otherwise specified.
Example 1
22 parts of urethane acrylate EB230 (manufactured by Daicel UCB), 40 parts of trimethylolpropane ethylene oxide modified triacrylate, 20 parts of tripropylene glycol diacrylate, 10 parts of 2-acryloyloxypropyl hydrogen phthalate, tripropylene glycol diacrylate dispersion of carnauba wax 8 parts of a body (manufactured by Shamrock Co., carnauba wax content 25%) was mixed to prepare an electron beam curable overprint varnish.
Next, Fine Star R39 Ai (printing ink manufactured by Toyo Ink Manufacturing Co., Ltd.) was applied to one side of a 50 μm thick PET film with a bar coater and dried with a dryer. On the printed surface, the electron beam curable overprint varnish is applied with a bar coater, and an acceleration voltage of 50 kV is absorbed using Min-EB (electron beam irradiation device manufactured by Toyo Ink Manufacturing Co., Ltd.) from the coating layer side. By irradiating and curing under the conditions of a dose of 40 KGy and a nitrogen gas atmosphere (oxygen concentration 200 ppm), a coated product provided with an electron beam curable overprint varnish layer of about 3 μm was obtained.

Example 2
FD Carton ACE indigo (UV-curable printing ink manufactured by Toyo Ink Manufacturing Co., Ltd.) is printed on one side of art paper with a thickness of 50 μm using an RI tester, and output is 120 W using a Light Hunmmer6 (Fusion UV irradiation device). And cured at a conveyance speed of 30 m / min. By applying the electron beam curable overprint varnish prepared in Example 1 on this printed surface with a bar coater and irradiating and curing with an electron beam under the same conditions as in Example 1, about 3 μm A coated product provided with an electron beam curable overprint varnish layer was obtained.

Example 3
Polyester acrylate EB810 (manufactured by Daicel UCB) 40 parts, diethylene glycol diacrylate 40 parts, dipentaerythritol hexaacrylate 10 parts, carnauba wax tripropylene glycol diacrylate dispersion (manufactured by Shamrock, carnauba wax content 25%) 8 2 parts of polyethylene wax (manufactured by Shamrock) and 0.2 part of paint additive SH28PA (manufactured by Toray Dow Corning Silicone) were mixed to prepare an electron beam curable overprint varnish.
Next, fine star R39 indigo was applied to one side of a 50 μm thick PET film with a bar coater and dried with a dryer. An electron beam curable overprint varnish was coated on this printed surface with a bar coater, and Min-EB was used from the coating layer side, with an acceleration voltage of 50 kV, an absorbed dose of 40 KGy, and a nitrogen gas atmosphere (oxygen concentration of 200 ppm). By irradiating and curing under conditions, a coated product provided with an electron beam curable overprint varnish layer of about 3 μm was obtained.

Example 4
On one side of art paper with a thickness of 50 μm, FD Carton ACE indigo was printed with an RI tester and cured using Light Hunmmer 6 under conditions of an output of 120 W and a conveyance speed of 30 m / min. By applying the electron beam curable overprint varnish prepared in Example 3 on this printed surface with a bar coater and irradiating and curing with an electron beam under the same conditions as in Example 3, about 3 μm is obtained. A coated product provided with an electron beam curable overprint varnish layer was obtained.

Comparative Example 1
The electron beam curable overprint varnish prepared in Example 1 was mixed with 5 parts of a photopolymerization initiator Irgacure 907 (manufactured by Ciba Specialty Chemicals) to prepare an ultraviolet curable overprint varnish.
Next, fine star R39 indigo was applied to one side of a 50 μm thick PET film with a bar coater and dried with a dryer. UV curable overprint varnish is coated on this printed surface with a bar coater and cured from the coating layer side using Light Hunmmer 6 under conditions of 120W output and 30m / min. A coated product provided with a curable overprint varnish layer was obtained.

Comparative Example 2
On one side of art paper with a thickness of 50 μm, FD Carton ACE indigo was printed with an RI tester and cured using Light Hunmmer 6 under conditions of an output of 120 W and a conveyance speed of 30 m / min. An ultraviolet curable overprint varnish prepared in Comparative Example 1 was applied onto this printed surface with a bar coater, and cured by irradiating with ultraviolet rays under the same conditions as in Comparative Example 1 to cure about 3 μm. A coated product provided with a mold overprint varnish layer was obtained.

Comparative Example 3
The electron beam curable overprint varnish prepared in Example 3 was mixed with 8 parts of a photopolymerization initiator Irgacure 184 (manufactured by Ciba Specialty Chemicals) to prepare an ultraviolet curable overprint varnish.
Next, fine star R39 indigo was applied to one side of a 50 μm thick PET film with a bar coater and dried with a dryer. UV curable overprint varnish is coated on this printed surface with a bar coater and cured from the coating layer side using Light Hunmmer 6 under conditions of 120W output and 30m / min. A coated product provided with a curable overprint varnish layer was obtained.

Comparative Example 4
On one side of art paper with a thickness of 50 μm, FD Carton ACE indigo was printed with an RI tester and cured using Light Hunmmer 6 under conditions of an output of 120 W and a conveyance speed of 30 m / min. The ultraviolet curable overprint varnish prepared in Comparative Example 3 was applied on the printed surface with a bar coater and cured by irradiating with ultraviolet rays under the same conditions as in Comparative Example 3 to cure about 3 μm of ultraviolet light. A coated product provided with a mold overprint varnish layer was obtained.

<Evaluation method>
The coated product obtained as described above was evaluated by the following evaluation method.
<Drying test with tentacles>
The evaluation was made in four stages, ◎, ○, Δ, and ×.
<Abrasion resistance>
The surface of the overprint varnish layer was rubbed 1000 times with a fine paper while applying a load of 1000 g, and the presence or absence of scratches was evaluated visually. The evaluation was made in four stages, ◎, ○, Δ, and ×.
<Mat feeling>
Visual evaluation was made in four stages of ◎, ○, Δ, and ×.
<Mat feeling after friction>
According to Kanakin No. 3, the matte feeling after rubbing the surface of the overprint varnish layer 1000 times while applying a load of 1000 g was visually evaluated in four stages of ◎, ○, Δ, and ×.
<Adhesion>
Adhesive tape is applied to the surface of the overprint varnish layer to evaluate the adhesion when peeled off. The evaluation was made in four stages, ◎, ○, Δ, and ×.
<Evaluation results>
In the electron beam curable overprint varnish shown in the examples, the matte feeling after friction is maintained, and the dryness, scratch resistance, adhesion and the like are satisfied practically without problems, and the surface hardness and other physical properties are The balance was good.
The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 4 are summarized in Table 1.

  The electron beam curable overprint varnish of the present invention can be widely used for various substrates, in particular, a packaging material substrate and a seal label substrate.

Claims (4)

  An electron beam curable overprint varnish comprising an electron beam curable overprint varnish, comprising carnauba wax.   An electron beam curable overprint varnish containing an electron beam curable overprint varnish, wherein carnauba wax is contained in the varnish in a solid content of 10% by weight or less.   The electron beam curable overprint varnish according to claim 1 or 2, further comprising at least one selected from polytetrafluoroethylene, polyethylene, and lanolin. 4. A coated product obtained by coating the electron beam curable overprint varnish according to any one of claims 1 to 3 on a substrate which may have a printed layer, and curing by applying an electron beam. .