JP2009119678A - Manufacturing method of thick film printed matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the manufacturing method of thick film printed matter by which paper degradation can be suppressed to the minimum and ink which contains neither a solvent nor a photopolymerization initiator and which is soft to environment and is safe, is used in a field where low energy electron beams of 300 kV or less is utilized as a drying system of the printed matter. <P>SOLUTION: The manufacturing method of the thick film printed matter using oxidative polymerization combining super low energy electron beam curing type ink, is provided. The oxidative polymerization combining super low energy electron beam curing type ink comprises "a super low energy electron beam curing composition" which is cured by using super low energy level electron beams of 30 to 80 kV acceleration voltage and "an oxidative polymerization composition" which is dried by oxygen. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the field of using a low-energy electron beam of 300 kV or less as a drying method for printed matter, the present invention can reduce the paper degradation to a minimum and uses an environmentally friendly safe ink that does not contain a solvent or a photopolymerization initiator. It relates to a printed film.

  Examples of thick film printed matter having an ink film thickness of several tens of μm include engraved intaglio printed matter and screen printed matter. In engraving intaglio printing, the depth of the concave portion of the printing plate reaches up to 100 μm or more, but it is transferred to the printing paper that is part of the ink packed into the concave portion of the printing plate by fleshing, and the rise of the ink of the printed matter Is about 10 μm to 40 μm. In screen printing, in the case of a thick film screen, the ink film thickness is several tens of μm, and the ink viscosity is low.

  In the case of thick-film printed matter, the printing unit's paper output unit immediately overlaps the printed matter that was printed first, so the backside of the printed matter is stained with printing ink. Will occur. Also, because the ink of the printed paper that is stacked is sticky, it is called “blocking”, where the printed material adheres to each other when it dries, and if you try to forcefully peel the printed material, the paper will peel or tear. An event occurs.

  In order to solve such problems of “setback” and “blocking”, various methods have been proposed for engraving intaglio printing. For example, (1) Insert a slip between printed materials. (2) A solvent is added to the ink, and the ink is set by evaporating or penetrating the solvent from the ink after printing. (3) A method of reducing the fluidity after printing while maintaining the fluidity necessary for printing by hardening the ink at room temperature and performing warm printing at the time of printing.

  Further, as a more effective ink, an ink is proposed in which ultraviolet ray energy is applied from the outside to cure the ultraviolet ray curable component on the surface layer portion, and the inside of the ink film is polymerized and dried with an oxidation polymerization component (for example, Patent Document 1). reference).

  In addition, an ultraviolet polymerization type and an oxidation polymerization combined use type printing ink excellent in flexibility and curability have been proposed (for example, see Patent Document 2).

  Also, an electron beam drying type engraving intaglio ink applying a low energy electron beam excellent in transparency that is not influenced by optical transparency to an opaque ink layer such as printing ink has been proposed (for example, And Patent Document 3).

  On the other hand, there have been proposed inks and methods for improving pigment dispersibility and improving adhesion and adhesion to a substrate (printed body) by using an ultraviolet curing component and an oxidative polymerizable component. Means for synthesizing a photopolymerizable substance containing (oxidatively polymerizable component) in the molecule has been proposed (see, for example, Patent Documents 4, 5 and 6).

  As another example, an ink in which an alkyd resin (oxidation polymerization component) is mixed with a photopolymerization substance has been proposed (see, for example, Patent Document 7).

  On the other hand, a method has been proposed in which an oxidation polymerization type ink is irradiated with an electron beam in the presence of oxygen to activate a double bond in the molecule, and the ink is dried synergistically by generated ozone (for example, , See Patent Document 8).

Japanese Patent Publication No. 08-892 JP 2002-38065 A Japanese Patent No. 2969167 JP 49-97788 JP-A-51-16107 JP 50-95006 A JP 54-255941 A JP 2001-158080 A

  As a high-speed drying method for printed matter accompanying an increase in the speed of a printing press, an ink that is cured by ultraviolet irradiation is generally used. However, since many inks are colored with pigments, dyes, and the like, the thickness of an ink film that can be cured by ultraviolet irradiation is limited by the depth at which ultraviolet rays can pass.

  Ultraviolet drying is widespread in offset printing and the like, but in engraving intaglio printing that extends over several tens of μm, it is difficult to use these ultraviolet drying only systems. Even screen printing may not be used depending on the film thickness, degree of coloring, and the degree of penetration into the substrate, and depending on the substrate such as paper, if it is penetrable, it is impossible to dry only with ultraviolet rays.

  In the case of the inks proposed in Patent Document 1 and Patent Document 2, it is necessary to strengthen the cured film on the surface of the ink in order to ensure the effect of preventing the set-off, and the ultraviolet curing component in the ink varnish is oxidized. It may be more than the polymerization component, and may require a polyfunctional acrylate resin as the UV curing component. Use a polyfunctional acrylate resin to increase the curing speed, or blend a photopolymerization initiator. It is necessary to increase the amount.

  In engraving intaglio printing, a large amount of ink is discarded without being used for printing due to wiping, so there are more expensive acrylate resin components and photopolymerization initiators contained in this compared to oxidation polymerization varnish. Is also disadvantageous in terms of ink cost. In many cases, the wiping aptitude, which is most important in engraving intaglio printing, is impaired.

  In addition, in the ink system using UV curable varnish together, there are problems associated with odor problems and toxicity problems caused by the photopolymerization initiator, and further concerns such as migration of residual monomers due to UV drying. is there.

  In particular, in the printed matter such as food packaging and toys that place importance on safety, the use of the UV curable system is limited due to the safety problem of the remaining photopolymerization initiator and monomer.

  In the case of the ink proposed in Patent Document 3, when a radiation-collapse type printing base material represented by brittle paper is used even if the ink-cured film is hard, secondary generation such as deterioration of the printing base material occurs. It was a hindrance to practical use including problems.

  In the case of the inks proposed in Patent Document 4, Patent Document 5, Patent Document 6 and Patent Document 7, all of these proposals are intended only to improve pigment dispersibility, adhesion to the substrate, and adhesion. Therefore, as in the present invention, the surface layer of the film is instantaneously cured by ultraviolet irradiation, enabling stacking and secondary processing immediately after printing or coating, and then the inside of the film is naturally dried by oxidative polymerization. This is different from the primary method.

  In the method proposed in Patent Document 8, by irradiating an oxidative polymerization type ink in the presence of oxygen with an electron beam, activating double bonds in the molecule and synergistically drying the ink by generated ozone, The generated ozone damages the surface of the substrate, and the inside of the irradiation device needs to have specifications for corrosion resistance to ozone, and the generated ozone needs to be treated safely.

  Also, in ordinary printed matter, the area of the image line to be dried is small, but it is difficult to selectively irradiate only the image area with an electron beam. Irradiation will occur. However, when the printing substrate is paper, the cellulose constituting the paper is a radiation-decomposable natural polymer, so that the paper deteriorates when irradiated with an electron beam with a higher energy than 100 kV, and further resistant to Various strengths such as bending strength and tear strength are lowered.

  The present invention aims to solve the above-mentioned problems, and specifically, “ultra-low energy electron beam curing that cures by using an electron beam of an ultra-low energy level having a low energy acceleration voltage of 30 kV to 80 kV”. There is provided a method for producing a thick film printed material using an oxidation polymerization combined ultra-low energy electron beam curable ink containing a “composition” and an “oxidation polymerization composition” dried with oxygen.

  The method for producing a thick film printed material according to the present invention includes printing a predetermined pattern on at least a part of a base material with an ultra-low energy electron beam curable ink combined with oxidation polymerization, and using the ultra-low energy electron beam curable ink combined with oxidation polymerization. The substrate is printed by irradiating an ultra-low energy electron beam onto the printed material to cure from the surface of the ink film to the inside, and then the inside of the ink film on the printed material is dried.

  The method for producing a thick printed matter according to the present invention is characterized in that the acceleration voltage in an ultra-low energy electron beam is 30 kV to 80 kV.

  The method for producing a thick film printed material of the present invention includes an ultra-low energy electron beam curable composition in which an ink printed on a substrate is cured by irradiation with an ultra-low energy electron beam, and an oxidative polymerizable composition that is dried by oxygen. It contains a product.

  In the method for producing the thick film printed material of the present invention, in the ink printed on the substrate, the weight ratio of the ultra-low energy electron beam curable composition to the oxidation polymerizable composition is in the range of 95: 5 to 30:70. It is characterized by being.

  The printed material produced by the method for producing a thick film printed material according to the present invention is formed by printing a thick film on at least a part of the substrate with an ultra-low energy electron beam curable ink combined with oxidation polymerization. From the surface part of the ink film in the electron beam curable ink to the inside, it is cured by an ultra-low energy electron beam, and the inside of the ink film in the ultra-low energy electron beam curable ink combined with oxidative polymerization is dried by oxidative polymerization, The film in the ultra-low energy electron beam curable ink combined with oxidative polymerization is characterized in that the cross-linking density is continuously reduced from the surface of the ink film to the inside of the ink film.

  The thick film printed material of the present invention is characterized in that the ultra-low energy electron beam has an acceleration voltage of 30 kV to 80 kV.

  Since the accelerating voltage of the irradiated electron beam is ultra-low energy of 30 kV to 80 kV or less, the folding strength of the irradiated object (printing substrate) is higher than that when irradiating an electron beam with a higher accelerating voltage. The ink film surface can be instantaneously cured while suppressing the decrease.

  Since the coating surface layer portion is instantaneously cured and dried by this electron beam irradiation, the occurrence of set-off and blocking can be suppressed even if the printed matter is stacked immediately after printing. Since the uncured layer inside the ink film is naturally dried by oxidative polymerization, it is also possible to expect an adhesive effect by drying the component that penetrates the varnish in the ink into the paper substrate.

  Ultra low energy electron beam curable ink combined with oxidative polymerization has both electron beam curable and oxidative polymerization drying properties, and is much thicker than ink systems that have both UV curable and oxidative polymerization properties. A cured film can be formed from the ink surface layer to the inside.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the best mode for carrying out the invention described below, and various modes can be implemented within the scope of the technical idea in the claims.

  The oxidative polymerization combined ultra-low energy electron beam curable ink of the present invention includes various pigments, an oxidation polymerization catalyst, an antifriction agent, and a varnish obtained by singly or mixing materials having electron beam curable properties and oxidative polymerization properties. Consists of additives such as abrasives, ink properties adjustment and others.

  In order to enable high-speed drying and internal drying, an ink in which an electron beam curable vehicle and an oxidation-polymerizable vehicle are blended in a well-balanced manner according to different purposes such as ink film thickness and printing speed is required.

  The composition of the vehicle having both electron beam curability and oxidative polymerizability is a drying oil or semi-drying oil having a conjugated double bond and a modified alkyd resin, drying oil or semi-drying oil modified product of drying oil or semidrying oil. There are acrylic modified alkyd resin, alkyd resin or drying oil and acrylate mixture, etc. into which an acryloyl group has been introduced.

  As the electron beam curable component, (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, (caprolactone modified) dipentaerythritol exa (meth) acrylate, dipentaeryth Rutol penta (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, (alkylene oxide modified) trimethylolpropane tetra (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene Glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, (ethyl carbitol modified) 1,6-hexanediol di (meth) acrylate, 2 Examples thereof include methyl-1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, N-vinylpyrrolidone, acryloylmorpholine, and (meth) acrylate obtained by water-solubilizing these. These can be used in combination of several kinds. Use of acrylate is particularly effective when emphasizing electron beam curability.

  A dry oil or semi-dry oil, linseed oil, tung oil, soybean oil, coconut oil, cottonseed oil or the like having a conjugated double bond as an oxidatively polymerizable component, or a modification thereof can be used.

  Especially when wiping is required like engraving intaglio ink and excess ink on the plate surface is removed by an alkaline aqueous wiping method, the electron beam curable components include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) Use of acrylate, water-soluble epoxy acrylate, ethyl carbitol modified 1,6-hexanediol di (meth) acrylate, acryloylmorpholine or carboxylated (meth) acrylate or the like is effective. As the oxidation polymerization component, a resin obtained by further carboxylating a dry oil-modified alkyd resin is effective.

  As the ink, the aforementioned vehicle, coloring pigment, extender pigment and desiccant, and sometimes a polymerization inhibitor (suppressor) are required. Addition of additives such as wax is also effective in improving the fastness of the printed matter. In addition, since there is no restriction | limiting in the pigment which can be used for an ultra-low energy electron beam curable ink combined with oxidation polymerization, any kind of pigment can be used.

  Pigments are various organic and inorganic pigments, white inorganic pigments for applications such as ink flow characteristics or printability adjustment, titanium, which is a concealing pigment, optical functional materials, magnetic materials, conductive materials, and other functional materials. Any material can be used depending on the application of the ink.

  The ink used in the present invention does not require a photopolymerization initiator necessary for ultraviolet drying, and only requires a desiccant that dries the oxidative polymerization component. It is stable and storage stability is good. If necessary, the addition of a polymerization inhibitor (suppressor) further improves the storage stability of the ink. A known material can be used as the polymerization inhibitor (suppression), and examples thereof include p-methoxyphenol and (alkyl) hydroquinone.

  Other varnish components include cobalt borate, cobalt octylate, cobalt naphthenate, lead monoxide, and the like, which are metal compounds such as cobalt, manganese, lead, and iron that are oxidation polymerization catalysts. Various waxes called paraffin wax, ethylene / acrylic acid copolymer wax, ethylene / vinyl acetate copolymer wax, polyolefin wax, carnauba wax, etc. can be used with different properties as wax components for friction resistance and wear resistance. . As other additives, pigment dispersants, leveling agents and the like may be added.

  The ultra-low energy electron beam curable varnish used in combination with oxidation polymerization is prepared by appropriately mixing the above-mentioned electron beam curable component and oxidative polymerizable component, but the mixing ratio is oxidized with respect to 99 to 20% of the electron beam curable component. It is preferable to set it as 1-80% of polymeric components, More preferably, it is the range of 10-70% of oxidatively polymerizable components with respect to 90-30% of electron beam hardening components.

  The above-mentioned varnish component, a pigment, an additive, and the like are kneaded by a known apparatus and method such as a three-roll mill or a bead mill to produce an ultralow energy electron beam curable ink combined with oxidation polymerization.

  Using ultra-low energy electron beam curable ink combined with oxidative polymerization, continuous printing is performed with a printing machine. The printed matter that is continuously printed passes through the electron beam irradiation device immediately after printing, and is stacked as it is on the paper discharge unit. The electron beam irradiated at this time is preferably from a very low acceleration voltage to an acceleration voltage of 20 kV to 300 kV. Considering the influence of electron beam irradiation on the printing substrate, it is preferable to set the acceleration voltage to 150 kV at which the irradiated electron beam does not reach the substrate. More preferably, taking advantage of the characteristics of ultra-low energy electron beam curable ink combined with oxidative polymerization, the inside is preferably an acceleration voltage up to 80 kV that effectively acts on the order of several tens of μm from the surface to be dried by oxidative polymerization. . In consideration of the electron beam extraction efficiency of the electron beam irradiation apparatus, it is effective to irradiate an electron beam accelerated at an acceleration voltage of 30 kV to 80 kV.

  The irradiation dose of the electron beam is within a range in which almost all reactive groups of the electron beam curing component of a few tens of μm from the surface react, and some unsaturated bond reacts, so that the main chain cleavage of the molecule is not dominant. It is preferable to irradiate a dose. In view of the polymerizability of the ink by the electron beam and the power efficiency, it is more preferable to set it in the range of 10 kGy to 100 kGy.

  The stacked continuous printed matter is left to stand for 1 to several days in the loaded state in order to perform internal drying by oxidation polymerization. After sufficiently drying by oxidative polymerization, even if the stacked printed products are handled, they can be printed as individual printed products without any resistance.

  At this time, in the ultra-low energy electron beam curable ink combined with oxidative polymerization, the ink film is cured with a crosslinking reaction by an ultra-low energy electron beam having an acceleration voltage of 30 kV to 80 kV from the surface of the ink film to the inside. Since it is dried by oxidative polymerization, it becomes a film in which the irradiation effect of the ultra-low energy electron beam is expressed in a slanting manner from the surface of the ink film to the inside of the ink film. “Inclined coating” refers to an ink coating that has been cured by a state in which the surface layer portion of the printed material has a high crosslinking density and the crosslinking density continuously decreases as it enters the inside. Since the dose of the surface layer portion of the printed material is high and the dose decreases as it enters the inside, the film has a performance obtained by a phenomenon that produces strong properties as a whole film.

  This is due to the fact that the surface of the ink was polymerized at a sufficient crosslinking density by electron beam irradiation, so that the surface tack did not remain and was cured to a high hardness. Therefore, there is no “set-off” on the paper stacked on top.

  Since a high crosslinking density is obtained by polymerization by electron beam irradiation, a good effect on fastness such as choking resistance can be obtained. The “crosslinking (crosslinking) reaction” means that when various polymers are irradiated with an electron beam, the bonds in the molecule are broken and radicals are generated, and the generated radicals react with each other to form molecules of the polymer material. It is a reaction in which a new chemical bond occurs between them and it has a network structure. The “crosslinking density” is a parameter representing the number of crosslinks per unit.

  If it is possible to suppress the occurrence of “set-off”, it will be possible not only to improve workability, but also to design a thick swell-printed product with a high swell. It is possible to obtain printed matter with high added value that is rich in anti-counterfeiting effects and design properties.

  Thereby, the workability in the printing work can be improved, that is, the restrictions on the handling of the printed matter in the paper discharge unit of the printing machine and the movement of the printed matter after printing can be greatly reduced.

  By combining electron beam curing and oxidative polymerization, the surface where the ultra-low energy electron beam works most strongly has a high crosslink density and high strength. Since a high oxidation polymerization component polymerizes while relaxing the internal stress naturally, there is also penetration of the oxidation polymerization component into the base material, and adhesion and adhesion to the base material can be provided.

  Various materials were blended based on the blending examples shown in Table 1, and kneaded by a conventional method using a three-roll mill to prepare an ultralow energy electron beam curable ink combined with oxidation polymerization. As a result of measuring the viscosity and yield value of the kneaded ink using a viscoelasticity measuring device (Reostress 600 type manufactured by HAAKE), the viscosity at 25 ° C. was 12.1 Pa · s and the yield value was 957 Pa. Although it depends on the wiping method, if the ink viscosity is too high, it is difficult to wipe off excess ink on the engraving intaglio plate surface. When such an event occurs, it is possible to respond by decreasing the printing speed, increasing the peripheral speed ratio of the wiping roller, or increasing the plate surface temperature.

  The ultra-low energy electron beam curable ink used in combination with oxidative polymerization was printed on an intaglio plate surface having a depth of 150 μm on a security printing paper using an intaglio printing aptitude tester. Compared with the ultra-low energy electron beam curable ink combined with oxidation polymerization and the conventional engraving intaglio ink (oxidation polymerization type), the intaglio printing machine showed a good printability. The printed matter was irradiated with 40 kGy at an acceleration voltage of 60 kV using an electron beam irradiation device (Ushio Electric Co., Ltd. micro-electron beam irradiation device Min-EB labo SFY01).

  The same unprinted security paper is placed on the printed matter after the electron beam irradiation, and the printing speed is 0.5 m / min. With a printing aptitude tester (manufactured by Kumagai Riki Kogyo). Then, 1kg, 2kg, 5kg, 10kg, 20kg, 30kg, 40kg and 50kg were set, and the load was changed by pressing the load with an aluminum plain disk, and the load was applied by the paper loaded at the paper discharge unit of the printing press. The state of occurrence of set-off according to the state was simulated, and the set-off resistance and blocking resistance of the ink film obtained by curing the ink surface by electron beam irradiation were evaluated.

  As shown in FIG. 1, in the printed paper of the security paper after the electron beam irradiation, up to 5 kg, no smudge due to ink transfer after printing was observed, and very little ink was applied at a load of 10 kg or more. Although a transition was observed, it was found that even when 50 kg was used, the film was not significantly soiled, and a strong dry film was formed on the surface layer portion.

  That is, intaglio printing of ultra-low energy electron beam curable ink combined with oxidative polymerization is possible even when a 5 kg load is applied at a slow speed with a printability tester (manufactured by Kumagai Riki Kogyo) at a linear pressure. There was no breakage and no set-off due to the uncured ink inside.

  Intaglio printing of ultra-low energy electron beam curable ink combined with oxidation polymerization is the result of continuous measurement of hardness in the depth direction with the surface and interface property analyzer (Daipura Wintes) after curing the oxidation polymerization component Is shown in Table 2. It has a continuous physical property change that the surface is hard and the inside is soft, and it was confirmed that a strong cured film having both strength and flexibility was obtained.

  Engraving intaglio printed material of ultra-low energy electron beam curable ink combined with oxidation polymerization, after curing of the oxidation polymerization component, a tough cured film having both strength and flexibility is obtained, without causing cracks, cracks, peeling, etc. There was no particular problem.

  In addition, the electron beam-cured surface has a high crosslink density, excellent resistance to chemicals, friction resistance, fastness, etc. It is hard and the inside has ideal ink film properties that retain flexibility.

  In addition, the ultra-low energy electron beam curable ink combined with oxidation polymerization does not require a photopolymerization initiator, so there is no instability of ink storage due to the photopolymerization initiator, and a polymerization inhibitor (suppression) agent to be added as necessary. Can be reduced.

  In addition, since the transmission of the electron beam does not depend on the color of the ink, there are no particular restrictions on the color pigments that can be used, so any kind of pigment can be used.

  Furthermore, although an intaglio printing press was used in this example, since a low-viscosity component that easily penetrates can be dried before penetrating into the inside of the paper, an effect of preventing the low-viscosity component from falling through can be obtained. High-speed screen printing is also possible.

  Various materials were blended based on the blending examples shown in Table 3, and kneaded by a usual method using a three-roll mill to prepare a radiation curable improvement type ultra-low energy electron beam curable ink combined with oxidation polymerization. As a result of measuring the viscosity and yield value of the kneaded ink using a viscosity and viscoelasticity measuring device (Reostress 600 type manufactured by HAAKE), the viscosity at 25 ° C. was 23.4 Pa · s and the yield value was 535 Pa.

  The ultra-low energy electron beam curable ink combined with oxidation polymerization was printed on a security printing paper using an intaglio plate surface having a plate depth of 150 μm using an intaglio printing aptitude tester. Compared with conventional engraving intaglio ink (oxidation polymerization type), the ultra-low energy electron beam curable ink used in combination with oxidation polymerization exhibited a good printability on an intaglio printing press. The printed matter was irradiated with 40 kgy at an accelerating voltage of 60 kV using an electron beam irradiation device (Ushio Electric Co., Ltd. micro-electron beam irradiation device Min-EB labo SFY01).

  The same non-printed securities paper is placed on the printed matter after the electron beam irradiation, and the printing speed is 0.5 m / min. With a printing aptitude tester (manufactured by Kumagai Riki Kogyo). With 1kg, 2kg, 5kg, 10kg, 20kg, 30kg, 40kg and 50kg, the load is applied by the paper loaded on the paper discharge unit of the printing press while changing the load with a plain aluminum disk The occurrence of set-off caused by the ink was simulated, and the anti-set-off and blocking resistance of the ink film having the ink surface cured by electron beam irradiation was evaluated.

  As shown in Fig. 2, the printed matter on the security paper after electron beam irradiation shows no smudge due to ink transfer after printing up to 5 kg, and very slight ink transfer at a load of 10 kg or more. However, it was found that even when 50 kg was used, the film was not greatly soiled, and a strong dry film having both strength and flexibility was formed from the surface layer portion to the inside.

  Intaglio printing of ultra-low energy electron beam curable ink combined with oxidative polymerization does not destroy the ink film even if a 5 kg load is applied at a slow linear pressure with a printability tester (manufactured by Kumagaya Rikyu Kogyo). No set-up happened.

  The intaglio printed matter of the ultra-low energy electron beam curable ink combined with oxidative polymerization was subjected to 100 round-trip friction tests with a cotton cloth with a load of 200 g after curing the oxidative polymerization component using a Gakushin type friction tester. As a result, as shown in FIG. 3, although transfer of the ink to the friction cloth was recognized, no dropout or smudge was observed in the image line portion, the image line state was good, and excellent friction fastness was obtained. I understood that I have it.

  Results of chemical resistance test by immersing an intaglio print of ultra-low energy electron beam curable ink combined with oxidative polymerization in acid, alkali and organic solvent (acetone) for 5 hours after curing oxidative polymerization component (see FIG. 4) As shown in the figure, no chemical changes such as leaching or peeling were observed in any of the chemicals, and it was confirmed that the chemical resistance was good.

(Comparative Example 1)
Various materials were blended based on the blending examples shown in Table 4, and kneaded by an ordinary method using a three-roll mill to prepare engraving intaglio ink combined with ultraviolet curing and oxidation polymerization. As a result of measuring the viscosity and yield value of the kneaded ink using a viscosity and viscoelasticity measuring device (Reostress 600 type manufactured by HAAKE), the viscosity at 25 ° C. was 1403 Pa · s and the yield value was 1105 Pa.

The UV curing and oxidation polymerization combined use intaglio ink was printed on a security printing paper with a plate surface having an intaglio plate surface depth of 150 μm using an intaglio printing aptitude tester. The printed matter was irradiated with 80 mJ / m ² with an air-cooling type 120 W / cm and a metal halide lamp with an ultraviolet irradiation device (conveyor UV irradiation device manufactured by Nippon Battery Co., Ltd.).

  Place the same non-printed security paper on the paper after the ultraviolet irradiation, and use a printability tester (manufactured by Kumagai Riki Kogyo) to print at a printing speed of 0.5 m / min. 1 kg, 2 kg and 5 kg are set, and the load is changed with an aluminum plain disk and the pressure is changed, and the occurrence of set-off due to the load applied by the paper loaded in the paper discharge unit of the printing press is simulated, and ultraviolet rays are simulated. The anti-set-off resistance and blocking resistance of the ink film whose ink surface was cured by irradiation were evaluated.

  As shown in FIG. 5, in the printed paper of the security paper after the ultraviolet irradiation, the transfer of the ink after printing was recognized over the entire image line even with a load of 1 kg, and a strong dry film was obtained on the surface. I found that there was no.

  Results of continuous measurement of changes in hardness in the depth direction by UV and curing intaglio printing of oxidation polymerization type intaglio ink using a surface and interface property analyzer (Daipura Wintes) after curing the oxidation polymerization component Is shown in Table 5. It was confirmed that the material had relatively no change from the surface to the inside of about 20 μm.

(Comparative Example 2)
Various materials were blended based on the blending examples shown in Table 6, and kneaded by a usual method using a three roll mill to prepare an ultraviolet curability improving type ultraviolet curing and oxidative polymerization combined engraving intaglio ink. As a result of measuring the viscosity and yield value of the kneaded ink using a viscosity and viscoelasticity measuring apparatus (Reostress 600 type manufactured by HAAKE), the viscosity at 25 ° C. was 21.11 Pa · s and the yield value was 1146 Pa.

The UV curing and oxidation polymerization combined use intaglio ink was printed on a security printing paper with a plate surface having an intaglio plate surface depth of 150 μm using an intaglio printing aptitude tester. The printed matter was irradiated with 80 mJ / m ² with an air-cooling type 120 W / cm and a metal halide lamp with an ultraviolet irradiation device (conveyor UV irradiation device manufactured by Nippon Battery Co., Ltd.).

  Place the same non-printed security paper on the paper after the ultraviolet irradiation, and use a printability tester (manufactured by Kumagai Riki Kogyo) to print at a printing speed of 0.5 m / min. 1 kg, 2 kg and 5 kg are set, and the load is changed with an aluminum plain disk and the pressure is changed, and the occurrence of set-off due to the load applied by the paper loaded in the paper discharge unit of the printing press is simulated, and ultraviolet rays are simulated. The anti-set-off resistance and blocking resistance of the ink film whose ink surface was cured by irradiation were evaluated.

  In the ultraviolet curing and oxidation polymerization combined use intaglio ink blended so as to improve the ultraviolet curability, the set-off is reduced as compared with the ink of the blend of Comparative Example 1, but as shown in FIG. It was found that even after a load of 1 kg, the transfer of the ink after printing was observed almost throughout the image line, and sufficient surface drying was not obtained.

  An intaglio print of UV-curing and oxidation polymerization combined use intaglio ink blended so as to improve ultraviolet curability is cured 100 times back and forth with cotton cloth using a Gakushin type friction tester after curing of the oxidation-polymerization component. A friction test was performed. As a result, as shown in FIG. 7, the transfer of ink to the friction cloth was recognized, and although the ink in the image area remained sufficiently, the friction surface was stained, and the surface of the image line was It was possible to observe the light shaving, and it was found that the printed image line had poor friction fastness.

  An intaglio printing of UV curing and oxidation polymerization type intaglio ink formulated to improve UV curability is immersed in acid, alkali and organic solvent (acetone) for 5 hours after curing the oxidation polymerization component, and chemical resistance test The results of performing are shown in FIG. As a result, there was no change such as leaching or peeling with acid and acetone, and the chemical resistance was good, but the entire area was slightly discolored by alkali soaking and the gloss of the image area was lost.

  Next, in order to investigate the difference in the effects of low-energy electron beam irradiation equipment and ultra-low-energy electron beams on the irradiated object (printing substrate), deterioration is remarkable as an example of deterioration behavior when paper is irradiated. The folding strength test was performed based on JIS P8115.

  FIG. 9 shows the result of measuring the depth dose distribution using a low energy electron beam irradiation apparatus and an acceleration voltage of 200 kV, and the result of measuring the depth dose distribution using an ultra low energy electron beam irradiation apparatus and the acceleration voltage of 40 to 60 kV. Shown in

  In FIG. 9, the x-axis corresponds to the electron beam arrival depth in a substance with a specific gravity of 1. At an acceleration voltage of 200 kV in FIG. 9A, the material having a specific gravity of 1 reaches about 400 μm. Although it varies depending on the specific gravity of the irradiated material, it can be completely transmitted through the thickness of the printing ink and cured to the inside. Most inks used in products, including intaglio printing, have a film thickness of 50 μm or less, and among the electron beams irradiated to the image area, there are few electron beams that contribute to curing, and most of them are transmitted. It can be easily understood that the film thickness of printing and coating is excessive even at 200 kV, which falls into the low energy classification.

  On the other hand, (b) when the acceleration voltage is 40 to 60 kV, the material having a specific gravity of 1 at 60 kV is up to 40 several μm, and at 50 kV, it is up to 30 several μm, and all are absorbed by 50 μm. At 40 and 50 kV, more than 80% of the energy is used up to 10 μm. It can be made to act efficiently on the thickness of printing ink.

  From this dose attenuation state, at the film thickness of the printing ink level, the surface becomes a high-strength film with a high resin crosslinking density due to the high dose, and the inside becomes flexible and soft because the bridge becomes loose. It was expected that a moderate gradient effect with adhesiveness could be provided. Further, in printing on paper, an ink film on the paper has an ink component penetrating inside even if it is several μm. With penetrating power of an electron beam of 40 to 60 kV, the penetrating ink component can be cured in the film thickness of offset, letterpress, flexo and screen (if not too thick) printing.

  In order to see the difference in the influence of electron beam energy on the irradiated object, FIG.

  From the graph of FIG. 10, it can be seen that the decrease in the number of folding times is small with respect to the dose irradiated at 50 kV compared to 200 kV, that is, deterioration is suppressed. In particular, the difference becomes more prominent as the irradiation dose increases. This is due to the transparency of the electron beam, and at 50 kV where the transmission power is low, most of the radiation acts near the surface even if the irradiation amount is large, so it is considered that the entire paper does not deteriorate. Although it is a result of the blank paper which has not been printed, in the case of the paper on which printing has been performed, it is expected that deterioration is suppressed by absorption by the ink applied on the paper even slightly.

  11A and 11B are conceptual diagrams when the printed matter is irradiated with an electron beam. As can be seen from the data of the depth dose distribution in FIG. 9A, when the acceleration voltage shown in FIG. 11A is 200 kV, the penetrating power is high, so that the electron beam acts on the entire ink layer and the substrate. There is damage to the substrate as indicated by the “x” mark. Further, it can be seen from the curve of FIG. 9A that the relative dose shows the maximum value when it enters the inside of several tens of microns from the surface. Considering the printed matter, it acts more strongly on the underlying substrate than on the ink layer portion.

  On the other hand, when the acceleration voltage shown in FIG. 11B is 40 to 60 kV, the penetrating power is small, so that the electron beam is absorbed within 50 μm. It works efficiently on the ink layer and stops the electron beam in the middle of the substrate. Therefore, deterioration of the substrate is suppressed. This is one result showing that the deterioration of the base material, which has been a problem in the conventional electron beam apparatus, can be suppressed.

It is a figure which shows the reverse resistance and blocking resistance of an ink film in the evaluation method which simulated the state where the load was applied immediately after printing of the intaglio printed matter using an ultra-low energy electron beam curable ink combined with oxidation polymerization. Ink film anti-set-off resistance in an evaluation method that simulates a state in which a load is applied immediately after printing an intaglio print using an ultra-low energy electron beam curable ink combined with oxidation polymerization that is formulated to further improve electron beam curability. It is a figure which shows blocking resistance. It is a figure which shows the anti-friction test result of the intaglio print using the superposition | polymerization combined use super low energy electron beam curable ink mix | blended so that electron beam curability may be improved more. The chemical-resistance test result of the intaglio print using the ultra-low energy electron beam curable ink combined with oxidation polymerization blended so as to further improve the electron beam curability is shown. The anti-set-off resistance and blocking resistance of an ink film in an evaluation method simulating a state in which a load is applied immediately after printing of an intaglio printed material using engraving intaglio ink combined with ultraviolet curing and oxidation polymerization are shown. Ink film anti-set-off and anti-blocking properties in an evaluation method that simulates a state in which a load is applied immediately after printing of an intaglio print using engraving intaglio ink combined with UV curing and oxidation polymerization formulated to further improve UV curability Showing gender. The result of a rub resistance test of an intaglio print using an engraving intaglio ink combined with ultraviolet curing and oxidation polymerization formulated so as to further improve the ultraviolet curability is shown. The chemical-resistance test result of the intaglio printing using the engraving intaglio ink combined with ultraviolet curing and oxidation polymerization blended so as to further improve the ultraviolet curability is shown. (A) shows the result of measuring the depth dose distribution with an acceleration voltage of 200 kV with a low energy electron beam irradiation device, and (b) shows the depth dose distribution with an acceleration voltage of 40-60 kV with an ultra low energy electron beam irradiation device. The measurement results are shown. The folding resistance test result in the irradiated object when irradiated with a low energy electron beam and when irradiated with an ultra low energy electron beam is shown. (A) shows the conceptual diagram of the influence on the irradiation object in low energy electron beam irradiation, (b) shows the conceptual diagram of the influence on the irradiation object in ultra-low energy electron beam irradiation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Print image part 2 Ink reversely transferred by pressure 3 Ink transferred to friction cloth by friction test 4 Untested part in chemical resistance test 5 Alkaline liquid immersion part in chemical resistance test 6 Acidic liquid in chemical resistance test Immersion part 7 Acetone immersion part in chemical resistance test

Claims (4)

A method for producing a printed matter using an ink containing an electron beam curable composition and an oxidative polymerizable composition,
Print a predetermined pattern on the base material using the ink,
A thick film characterized by irradiating an ultra-low energy electron beam on a substrate on which the ink is printed, so that the ink film is cured from the surface of the ink film to the inside, and then the inside of the ink film is dried. A method for producing printed matter. 2. The method for producing a thick film printed matter according to claim 1, wherein an acceleration voltage in the ultra-low energy electron beam is 30 to 80 kV. 3. The thickness according to claim 1, wherein the ink contains an ultra-low energy electron beam curable composition that is cured by irradiation with an ultra-low energy electron beam, and an oxidative polymerizable composition that is dried by oxygen. A method for producing a printed film. 4. The thick film according to claim 1, wherein the ink has a weight ratio of the ultra-low energy electron beam curable composition to the oxidative polymerizable composition in a range of 95: 5 to 30:70. A method for producing printed matter.

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