JP2007111984A - Energy beam curable composition curing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety energy beam curable composition curing device superior in recording stability. <P>SOLUTION: This energy beam curable composition curing device applies a coating liquid including an energy beam curable composition to a base material P, and then cures the energy beam curable composition by irradiating it with an energy beam. The energy beam curable composition curing device comprises an energy beam curable composition applying section, an energy beam irradiation section 4, and a drive section for relatively moving the base material P from the energy beam curable composition applying section to the energy beam irradiation section 4. The energy beam curable composition curing device further comprises a light tight section 8 consisting of a softened material provided to the lowermost section of the energy beam irradiation section 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an energy beam curable composition curing device capable of stably curing an energy beam curable composition.

  In recent years, printing methods using ultraviolet curable or electron beam curable inks have attracted attention in flexographic printing, offset printing, and the like. Since these methods do not generate VOC and can shorten the drying time, they can be quickly transferred to post-processing, and can also be printed on a substrate having low ink absorbability such as a film.

  However, it is necessary to replace the irradiated part with an inert gas for electron beam curing. Even when ultraviolet rays are used, the light source needs to be sufficiently shielded from light, and if it is insufficient, the stability of the ink density is deteriorated or the safety of the operator cannot be ensured. In addition, it is effective to narrow the gap between the base material and the energy beam irradiation part in order to improve the light shielding property, but the probability of jam troubles increases and unnecessary heat radiation causes deformation of the heat-sensitive base material. There were issues such as. In addition, it is effective to apply or impregnate an energy ray-absorbing compound in the vicinity of the energy ray irradiation surface, such as a platen, or to use an energy ray-absorbing material. When used as an effect, the effect is reduced.

In the prior art, there is a description of light shielding regarding the print head (see, for example, Patent Document 1). However, it is effective when the number of recording portions is one, but when there are a plurality of recording portions, the light shielding performance deteriorates. Although there is a description about light shielding for the recording unit (for example, see Patent Document 2), only the recording unit is shielded from light, and there is no description about other parts.
JP 2004-284141 A (Claims and Examples) JP-A-2004-358533 (Claims and Examples)

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a safe energy beam curable composition curing apparatus having excellent recording stability and safety.

  The above object of the present invention can be achieved by the following configuration.

  1. In the energy beam curable composition curing apparatus, the energy beam curable composition for curing the energy beam curable composition by irradiating the energy beam after applying a coating liquid containing the energy beam curable composition to the substrate. The product curing device has an energy beam curable composition application unit and an energy beam irradiation unit, and relatively moves the substrate from the energy beam curable composition application unit in the direction of the energy beam irradiation unit. An energy beam curable composition curing apparatus, comprising: a drive unit that causes the light beam irradiation unit to have a light shielding unit made of a flexible material at the most downstream portion of the energy beam irradiation unit.

  2. 2. The energy ray-curable composition curing device according to 1 above, wherein the flexible material is fibrous and brush-shaped.

  3. 3. The energy beam curable composition curing device according to 1 or 2, wherein the energy beam curable composition applying unit and the energy beam irradiation unit are provided around a drum-shaped platen.

  4). The energy beam curable composition curing device according to any one of 1 to 3 is at least one selected from an inkjet printer, a flexographic printer, a gravure printer, and a lithographic printer. Energy ray curable composition curing device.

  According to the present invention, it is possible to provide a safe energy ray curable composition curing apparatus having excellent recording stability.

  The present invention will be described in more detail.

  As the energy ray according to the present invention, ultraviolet rays, visible light, infrared rays, electron beams and the like are used, and ultraviolet rays or visible light are preferable from the simplicity of the apparatus and the range of selection of the curable composition. In particular, ultraviolet rays are preferable from the viewpoint of curability. More preferably, ultraviolet rays having a peak wavelength of 200 to 300 nm are preferable.

  As the flexible material used for light shielding in the present invention, a brush-like material, a cloth-like material, or the like is used. The light shielding portion may be in contact with the cured surface or non-contact. Further, contact and non-contact may be repeated. In the case of contact, a material that is sufficiently soft so as not to damage the cured energy beam curable composition or the substrate is preferable. As the material, synthetic fiber, natural fiber, composite fiber, metal fiber, or the like can be used in a brush shape or a cloth shape.

  It is preferable that the energy ray-absorbing component is immersed and impregnated in the material used for the light shielding part in order to improve the light shielding property. When a material having a charge eliminating function is used as the material used for the light shielding portion, in the case of inkjet printing, there is an effect in reducing mist. Materials with static elimination function include carbon fiber, stainless steel fiber, sanderlon fiber (acrylic fiber + copper), Dyna fiber (heat resistant PVA fiber + copper + metal treatment), SA-7 fiber (acrylic + carbon fiber), amorphous A highly conductive material such as fiber is used.

  The light shielding part is preferably used on the outermost outer side of the irradiation part.

  Moreover, although the light-shielding part is used on the side opposite to the energy beam curable composition application part of the energy beam irradiation part, using it on the surface other than the energy beam curable composition application part side is an energy beam to unnecessary parts It is preferable for preventing irradiation.

  In order to evaluate the light shielding property, an illuminometer, a UV label whose color changes according to the amount of ultraviolet irradiation, and the like can be used. It is desirable to use a UV label because the measurement location is flexible.

  Next, the energy beam curable composition curing apparatus according to the present invention will be described with reference to the drawings as appropriate. The energy beam curable composition curing device shown in the drawings is only one aspect of the energy beam curable composition curing device that can be preferably used in the present invention. In the present invention, the energy beam curable composition exemplified here is used. It is not limited to the drawing of the curing device.

  FIG. 1 is a front view showing an example of a configuration of a main part used in a serial printing method in an ink jet energy beam curable composition curing device that can be used in the present invention. The energy beam curable composition curing apparatus 1 includes a head carriage 2, a recording head 3, an irradiation unit 4, a platen unit 5, and a light shielding unit 8 according to the present invention outside the irradiation unit 4. In the energy beam curable composition curing apparatus 1, the platen unit 5 is installed under the substrate P. The platen unit 5 absorbs excess energy rays that have passed through the substrate P and can reproduce a high-definition image very stably, and therefore preferably has a function of absorbing energy rays. As a result, a high-definition image can be reproduced very stably.

  In FIG. 1, any of the materials described above can be used as the material of the light shielding portion 8.

  The base material P is guided by the guide member 6 and moves from the near side to the far side in FIG. 1 by the operation of the conveying means (not shown). A head scanning unit (not shown) scans the recording head 3 held by the head carriage 2 by reciprocating the head carriage 2 in the Y direction in FIG.

  The head carriage 2 is installed on the upper side of the substrate P, and stores a plurality of recording heads 3 to be described later according to the number of colors used for image printing on the substrate P, with the discharge ports arranged on the lower side. The head carriage 2 is installed with respect to the main body of the energy ray curable composition curing device 1 so as to reciprocate in the Y direction in FIG. 1, and reciprocates in the Y direction in FIG. 1 by driving the head scanning means. .

  In FIG. 1, the head carriage 2 is illustrated as accommodating the recording heads 3 of yellow (Y), magenta (M), cyan (C), and black (K). The number of colors of the recording head 3 housed in the head carriage 2 can be determined as appropriate.

  The recording head 3 has a discharge means (inner) provided with a plurality of energy ray curable compositions (active energy ray curable ink: for example, UV curable ink) supplied by an ink supply means (not shown). By an operation (not shown), the liquid is discharged from the discharge port toward the substrate P. The active energy ray curable ink ejected by the recording head 3 is composed of a coloring material, a polymerizable monomer, an initiator, and the like, and the initiator acts as a catalyst when irradiated with ultraviolet rays. It has the property of being cured by crosslinking and polymerization reaction of monomers.

  The recording head 3 has a certain region (landing possible region) on the substrate P during scanning of moving from one end of the substrate P to the other end of the substrate P in the Y direction in FIG. ), The active energy ray-curable ink is ejected as ink droplets, and the ink droplets are landed on the landable region.

  The above-described scanning is performed as many times as necessary, and the active energy ray-curable ink is ejected toward one landable area, and then the substrate P is appropriately moved from the front to the back in FIG. While scanning by the scanning means, the recording head 3 discharges the active energy ray-curable ink to the next landable area adjacent to the rearward direction in FIG.

  By repeating the above operation and ejecting the active energy ray curable ink from the recording head 3 in conjunction with the head scanning means and the conveying means, an image made up of an aggregate of active energy ray curable ink droplets on the substrate P. Is formed.

  The irradiation unit 4 includes an ultraviolet lamp that emits ultraviolet light with stable exposure energy and a filter that transmits ultraviolet light having a specific wavelength when the active energy ray is ultraviolet light. Here, as the ultraviolet lamp, a mercury lamp, a metal halide lamp, an excimer laser, an ultraviolet laser, a hot cathode tube, a cold cathode tube, a black light, an LED (light emitting diode), etc. can be applied. Cathode tubes, mercury lamps or black lights are preferred.

  The irradiation unit 4 includes an energy beam curable composition curing device (active energy beam curable ink jet) in a landable region in which the recording head 3 ejects the active energy beam curable ink by one scan driven by the head scanning unit. The printer has a shape that is almost the same as the maximum that can be set by the printer 1 or larger than the landable area.

  The irradiation unit 4 is fixed on both sides of the head carriage 2 so as to be substantially parallel to the substrate P.

  As described above, as a means for adjusting the illuminance of the ink ejection unit, the entire recording head 3 is shielded from light, but in addition, the ink ejection of the recording head 3 is determined from the distance h1 between the irradiation unit 4 and the substrate P. It is effective to increase the distance h2 between the portion 31 and the base material P (h1 <h2), or to increase the distance d between the recording head 3 and the irradiation unit 4 (d is increased). Further, it is more preferable that a bellows structure 7 is provided between the recording head 3 and the irradiation unit 4.

  Here, the wavelength of the energy rays irradiated by the irradiation unit 4 can be changed as appropriate by exchanging the lamp or the filter provided in the irradiation unit 4.

  Examples of the energy ray curable composition include printing ink, varnish, and inkjet ink. The energy ray curable composition contains a polymerizable compound and, if necessary, a polymerizable initiator.

  FIG. 2 is a front view showing an example of a configuration of a main part of a flexographic printing energy beam curable composition curing apparatus that can be used in the present invention.

  The substrate P fed from the feed roll 10 passes through the roller 16 and is guided to the platen 5 which is an impression cylinder, and the first energy ray curable composition (actinic ray curable ink: for example, UV curable ink). Ink is applied at the applying portion. Ink is supplied from the ink reservoir 15 by the anix roll 13 according to the image set on the plate cylinder 12, but excess ink is scraped off by the doctor blade 14. The image-like ink applied to the plate cylinder 12 is transferred to the substrate P and cured by the irradiation unit 4. Similar stations are installed around the platen 5 which is a large number of impression cylinders, and inks of different colors are printed on the substrate P, respectively. FIG. 2 illustrates examples of Y, M, C, and K as in FIG. The base material P that has been printed is taken up by the take-up roll 11.

  In this invention, it has the light-shielding part 8 comprised with the flexible material in the most downstream part of the irradiation part 4. FIG. FIG. 3 is an explanatory diagram thereof. In FIG. 3, a light source 41, a light control plate 42, and a protection plate 43 are provided inside the irradiation unit 4. The substrate P to which ink has been applied is sent to the irradiation unit 4 in the direction of the arrow, but is exposed by the irradiation unit 4 and the ink is cured. At this time, if there is light leakage in the downstream direction, the stability of the ink concentration is deteriorated and the safety of the operator cannot be ensured. The present invention is an excellent invention that solves such problems.

  FIG. 3 a shows a conventional irradiation unit 4. Although the aspect of this invention is shown to FIG. 3 b-e, this invention is not limited to this. 3B to 3E, a light shielding unit 8 made of a flexible material is installed in the most downstream portion of the irradiation unit 4. Examples of the flexible material include the materials described above. FIG. 3d shows a case where the irradiation unit 4 is set in the direction of the cut line with respect to the circle of the platen 5 which is the impression cylinder at the upstream part of the lower side, not the central part of the lower side, and FIG. Unlike FIG. 2, the case where it is horizontal instead of a circle is shown.

  The energy beam curable composition according to the present invention is particularly described in “photocuring technology—resin / initiator selection and blending conditions and measurement / evaluation of curing degree— (Technical Association Information)”. This ink is compatible with “Curing system using photoacid / base generator (Section 1)”, “Photoinduced alternating copolymerization (Section 2)”, etc. of “System (Chapter 4)”.

  The ink according to the present invention is composed of a pigment, a photopolymerizable compound, a dispersant, a photoinitiator, and the like, and is photopolymerizable when the photoinitiator acts as a catalyst when irradiated with ultraviolet rays. It has the property of being cured by crosslinking or polymerization reaction of the compound. However, as the ink according to the present invention, the photoinitiator may be excluded when an ink that conforms to the “photo-induced alternating copolymerization (section 2)” of the above-mentioned reference is used.

  In the actinic ray curable ink of the present invention, the photopolymerizable compound is roughly classified into a radical polymerization ink containing a radical polymerizable compound and a cation polymerization ink containing a cationic polymerizable compound. Ink can be applied as the ink according to the present invention, respectively, and in the present invention, a hybrid ink in which radical polymerization ink and cationic polymerization ink are combined may be applied.

When the ink according to the present invention is a radical polymerization ink, the radical polymerizable compound is
(1) High solubility in water,
(2) low viscosity,
(3) There is photopolymerization,
(4) Performance such as excellent physical properties of the cured film is required, and radical polymerizable acrylic monomers can be suitably used.

Examples of radical polymerizable acrylic monomers include N, N-dimethylaminoethyl methacrylate, CH ₂ ═C (CH ₃ ) —COO—CH ₂ CH ₂ N (CH ₃ ) ₂ : N, N-dimethylaminoethyl acrylate, _{CH 2 = CH-COO-CH} 2 CH 2 N (CH 3) 2: N, N- dimethylaminopropyl _{methacrylate, CH 2 = C (CH 3} ) -COO-CH 2 CH 2 CH 2 N (CH 3) 2 : N, N-dimethylaminopropyl _{acrylate, CH 2 = CH-COO-} CH 2 CH 2 CH 2 N (CH 3) 2: N, N- dimethylamino _{acrylamide, CH 2 = CH-CON (} CH 3) 2: N, N-dimethylamino _{methacrylamide, CH 2 = C (CH 3} ) -CON (CH 3) 2: N, N- dimethylaminoethyl acrylamide, CH ₂ = CH-CO _{HC 2 H 4 N (CH 3} ) 2: N, N- dimethylaminoethyl _{methacrylamide, CH 2 = C (CH 3} ) -CONHC 2 H 4 N (CH 3) 2: N, N- dimethylaminopropyl acrylamide, _{CH 2 = CH-CONH-C} 3 H 6 N (CH 3) 2: N, N- dimethylaminopropyl _{methacrylamide, CH 2 = C (CH 3} ) -CONH-C 3 H 6 N (CH 3) 2: In addition, these quaternized substances are particularly preferred because they are excellent in colorant dyeing properties. In addition, (meth) acrylic acid ester of polyhydric alcohol, (meth) acrylic acid ester of glycidyl ether of polyhydric alcohol, (meth) acrylic acid ester of polyethylene glycol, (meth) acrylic acid ester of polyhydric alcohol ethylene oxide addition compound Known ultraviolet curable monomers and oligomers such as a reaction product of a polybasic acid anhydride and a hydroxyl group-containing (meth) acrylic acid ester are used. Among these substances, substances having high compatibility with ink and high hydrophilicity are appropriately selected and used. The amount of these water-soluble monomers used is preferably in the range of 1 to 40% by mass relative to the total mass of the ink.

  The main radical photoinitiators and sensitizers include, for example, acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophene, p-dimethylaminopropiophenone, benzophenone. 2-chlorobenzophenone, pp'-dichlorobenzophene, pp'-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin isobutyl ether, benzoin n -Butyl ether, benzyl dimethyl ketal, tetramethyl thiuram monosulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, azobisisobut Ronitrile, benzoin peroxide, di-tert-butyl peroxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1- (4-isopropylphenyl) -2-hydroxy- 2-methylpropan-1-one and methylbenzoyl formate. The amount used is preferably 0.1 to 10% by mass with respect to the total amount of the water-soluble monomer that is solidified by energy application.

  In the present invention, a cationic polymerization ink with little or no shrinkage at the time of curing is preferable because of its excellent functionality and versatility.

  When the ink according to the present invention is a cationic polymerization type ink, the photopolymerizable compound used preferably contains an epoxy compound having at least one oxirane group.

  Examples of the epoxy compound include the following aromatic epoxides, alicyclic epoxides, and aliphatic epoxides.

  Preferred as the aromatic epoxide is a di- or polyglycidyl ether produced by the reaction of a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof and epichlorohydrin, such as bisphenol A or an alkylene oxide thereof. Examples thereof include di- or polyglycidyl ethers of adducts, di- or polyglycidyl ethers of hydrogenated bisphenol A or its alkylene oxide adducts, and novolak-type epoxy resins. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

  As the alicyclic epoxide, cyclohexene oxide obtained by epoxidizing a compound having at least one cycloalkane ring such as cyclohexene or cyclopentene ring with a suitable oxidizing agent such as hydrogen peroxide or peracid. Or a cyclopentene oxide containing compound is preferable.

  Preferred aliphatic epoxides include di- or polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, and typical examples thereof include diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol or Diglycidyl ether of alkylene glycol such as diglycidyl ether of 1,6-hexanediol, polyglycidyl ether of polyhydric alcohol such as di- or triglycidyl ether of glycerin or its alkylene oxide adduct, polyethylene glycol or its alkylene oxide adduct Diglycidyl ethers of polyalkylene glycols such as diglycidyl ethers, polypropylene glycols or diglycidyl ethers of adducts thereof Tel and the like. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

  Among these epoxides, in view of fast curability, aromatic epoxides and alicyclic epoxides are preferable, and alicyclic epoxides are particularly preferable. In the present invention, one of the epoxides may be used alone, or two or more may be used in appropriate combination.

  In the present invention, from the viewpoint of safety such as AMES and sensitization, it is preferable to contain at least one of an epoxidized fatty acid ester and an epoxidized fatty acid glyceride as an epoxy compound having an oxirane group.

The epoxidized fatty acid ester and the epoxidized fatty acid glyceride are not particularly limited as long as an epoxy group is introduced into the fatty acid ester or fatty acid glyceride.
The epoxidized fatty acid ester is produced by epoxidizing an oleic acid ester, and examples thereof include methyl epoxy stearate, butyl epoxy stearate, octyl epoxy stearate and the like. Similarly, the epoxidized fatty acid glyceride is produced by epoxidizing soybean oil, linseed oil, castor oil and the like, and epoxidized soybean oil, epoxidized linseed oil, epoxidized castor oil and the like are used. Examples of commercially available epoxidized vegetable oils include Sansizer E-4030 manufactured by Shin Nippon Chemical Co., Ltd., Vf7170, Vf7190, Vf5075, Vf4050, Vf7010, Vf9010, Vf9040, and Vf7040 manufactured by ATOFINA Chemical.

  In addition, the cationic polymerization ink according to the present invention preferably includes a compound containing an oxetane ring for further improving curability and ejection stability.

  As the oxetane compound that can be used in the present invention, any known oxetane compound as introduced in JP-A Nos. 2001-220526 and 2001-310937 can be used. Further, the combined use of a monofunctional oxetane compound containing one oxetane ring and a polyfunctional oxetane compound containing two or more oxetane rings improves the film strength after curing and the adhesion to a recording medium. preferable.

  Furthermore, any known vinyl ether compound may be used in the cationic polymerization ink of the present invention.

  Examples of vinyl ether compounds include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, and trimethylol. Di- or trivinyl ether compounds such as propane trivinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexanedimethanol monovinyl ether, n-pro Vinyl ether, isopropyl vinyl ether, isopropenyl ether -O- propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether.

  Among these vinyl ether compounds, in consideration of curability, adhesion, and surface hardness, di- or trivinyl ether compounds are preferable, and divinyl ether compounds are particularly preferable. In the present invention, one of the above vinyl ether compounds may be used alone, or two or more thereof may be used in appropriate combination.

  In the ink according to the present invention, it is preferable that at least one of the photoinitiators is a photoacid generator.

  As the photoacid generator, for example, a chemically amplified photoresist or a compound used for photocationic polymerization is used (edited by Organic Electronics Materials Research Group, “Organic Materials for Imaging”, Bunshin Publishing (1993), 187. To page 192). Examples of compounds suitable for the present invention are listed below.

  As the photoacid generator, for example, a chemically amplified photoresist or a compound used for photocationic polymerization is used (edited by Organic Electronics Materials Research Group, “Organic Materials for Imaging”, Bunshin Publishing (1993), 187. To page 192). Examples of compounds suitable for the present invention are listed below.

First, B (C ₆ F ₅ ) ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ and CF ₃ SO ₃ ⁻ salts of aromatic onium compounds such as diazonium, ammonium, iodonium, sulfonium and phosphonium are listed. be able to.

  Specific examples of onium compounds that can be used in the present invention are shown below.

  Secondly, sulfonated substances that generate sulfonic acid can be mentioned, and specific compounds thereof are exemplified below.

  Thirdly, halides that generate hydrogen halide can also be used, and specific compounds thereof are exemplified below.

  Fourthly, an iron allene complex can be mentioned.

  Further, in the cationic polymerization ink according to the present invention, the amount of the photopolymerizable monomer added is 30 to 95% by mass of a compound having at least one oxetane ring and an epoxy compound having at least one oxirane group. 5 to 70% by mass, and preferably at least one vinyl ether compound is 0 to 40% by mass.

  Various additives other than those described above can be used in the actinic ray curable ink according to the present invention. For example, surfactants, leveling additives, matting agents, polyester resins for adjusting film properties, polyurethane resins, vinyl resins, acrylic resins, rubber resins, and waxes can be added. In addition, for the purpose of improving the storage stability of the cationic polymerization ink, any known basic compound can be used. Typical examples include basic alkali metal compounds, basic alkaline earth metal compounds, amines. And basic organic compounds such as

  By containing the basic compound, not only the ejection stability becomes good, but also the generation of wrinkles due to curing shrinkage is suppressed even under low humidity. As the basic compound, any known compounds can be used, and typical examples include basic alkali metal compounds, basic alkaline earth metal compounds, and basic organic compounds such as amines.

  Examples of basic alkali metal compounds include alkali metal hydroxides (eg, lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.), alkali metal carbonates (eg, lithium carbonate, sodium carbonate, potassium carbonate, etc.), Examples include alkali metal alcoholates (for example, sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, and the like).

  As the basic alkaline earth metal compound, similarly, an alkaline earth metal hydroxide (eg, magnesium hydroxide, calcium hydroxide, etc.), an alkali metal carbonate (eg, magnesium carbonate, calcium carbonate, etc.), Examples include alkali metal alcoholates (eg, magnesium methoxide).

  Examples of the basic organic compound include amines and nitrogen-containing heterocyclic compounds such as quinoline and quinolidine. Among these, amines are preferable from the viewpoint of compatibility with the photopolymerization monomer, for example, octylamine, naphthylamine, Xylenediamine, dibenzylamine, diphenylamine, dibutylamine, dioctylamine, dimethylaniline, quinuclidine, tributylamine, trioctylamine, tetramethylethylenediamine, tetramethyl-1,6-hexamethylenediamine, hexamethylenetetramine and triethanolamine, etc. Is mentioned.

  The concentration when the basic compound is present is preferably in the range of 10 to 1000 ppm by mass, particularly 20 to 500 ppm by mass relative to the total amount of the photopolymerizable monomer. In addition, a basic compound may be used individually or may be used in combination of multiple.

  As the recording material that can be used in the image forming method of the present invention, various types of non-absorbable plastics and films used for so-called soft packaging can be used in addition to ordinary uncoated paper and coated paper. Examples of the plastic film include polyethylene terephthalate (PET) film, stretched polystyrene (OPS) film, stretched polypropylene (OPP) film, stretched nylon (ONy) film, polyvinyl chloride (PVC) film, polyethylene (PE) film, An acetyl cellulose (TAC) film can be mentioned. As other plastics, polycarbonate, acrylic resin, ABS, polyacetal, PVA, rubbers and the like can be used. Moreover, it is applicable also to metals and glass. Among these recording materials, the structure of the present invention is effective particularly when an image is formed on a PET film, an OPS film, an OPP film, an ONy film, or a PVC film that can be shrunk by heat. These substrates are not only susceptible to curling and deformation of the film due to ink curing shrinkage and heat generation during the curing reaction, but also the ink film is difficult to follow the substrate shrinkage.

  The surface energy of these various plastic films varies greatly depending on the characteristics of the material, and it has been a problem that the dot diameter after ink landing changes depending on the recording material. With the configuration of the present invention, a good high-definition image can be formed on a wide range of recording materials having a surface energy of 35 to 60 mN / m, including OPP films having a low surface energy, OPS films, and PET having a relatively large surface energy. .

  In the present invention, it is more advantageous to use a long (web) recording material in terms of the cost of the recording material such as packaging cost and production cost, the production efficiency of the print, and the ability to cope with printing of various sizes. is there.

  The ink according to the present invention preferably constitutes an inkjet ink set having at least a yellow inkjet ink, a magenta inkjet ink, a cyan inkjet ink, and a black inkjet ink, and is generally used for so-called color inkjet printing. It refers to an ink set in which a plurality of inks are set. In the image forming method of the present invention, it is preferable that the ink-jet ink set is composed entirely of the ink according to the present invention. When an ink-jet image is formed using this ink set, an image in which color mixing is solved is formed. Can do.

  Furthermore, in order to form a photographic image by inkjet, so-called dark and light inks having different pigment contents can be prepared and used. It is also preferable for color reproduction to use special color inks such as red, green, blue, and white as necessary.

  A pigment can be used for the actinic ray curable composition of the present invention. Various things, such as an organic pigment and / or an inorganic pigment, can be used. Specifically, white pigments such as titanium oxide, zinc white, lead white, litbon, and antimony oxide, black pigments such as aniline black, iron black, and carbon black, yellow lead, yellow iron oxide, Hansa Yellow (100, 50, 30 etc.), yellow pigments such as titanium yellow, benzine yellow and permanent yellow, orange pigments such as chrome vermilon, permanent orange, balkan first orange and indanthrene brilliant orange, brown such as iron oxide, permanent brown and para brown Pigment, Bengala, Cadmium Red, Antimony Zhu, Permanent Red, Rhodamine Lake, Alizarin Lake, Thioindigo Red, PV Carmine, Monolite Fast Red and Quinacridone Red Pigment, Cobalt Purple, Manganese Purple, Purple violet pigments such as first violet, methyl violet lake, indanthrene brilliant violet, dioxazine violet, ultramarine, bitumen, cobalt blue, alkali blue lake, metal free phthalocyanine blue, copper phthalocyanine blue, indanthrene blue and indigo In addition to green pigments such as blue pigment, chrome green, chromium oxide, emerald green, naphthol green, green gold, acid green rake, malachite green rake, phthalocyanine green and polychlorobrom copper phthalocyanine, various fluorescent pigments, metal powder pigments, Examples include extender pigments.

C. I Pigment Yellow-1, 3, 12, 13, 14, 17, 42, 74, 81, 83, 87, 93, 95, 109, 120, 128, 138, 139, 151, 166, 180, 185
C. I Pigment Orange-16, 36, 38
C. I Pigment Red-5, 22, 38, 48: 1, 48: 2, 48: 4, 49: 1, 53: 1, 57: 1, 63: 1, 101, 122, 144, 146, 177, 185
C. I Pigment Violet-19, 23
C. I Pigment Blue-15: 1, 15: 3, 15: 4, 18, 60, 27, 29
C. I Pigment Green-7, 36
C. I Pigment White-6, 18, 21
C. I Pigment Black-7
For the dispersion of the pigment, for example, a ball mill, sand mill, attritor, roll mill, agitator, Henschel mixer, colloid mill, ultrasonic homogenizer, pearl mill, wet jet mill, paint shaker, or the like can be used. As the dispersion medium, it is preferable in view of dispersion suitability to select a photopolymerizable compound, and among them, a monomer having the lowest viscosity.

  In the present invention, in order to obtain a sufficient concentration and sufficient light resistance, the pigment is preferably contained in the actinic ray curable composition in the range of 1 to 50% by mass.

  In addition to the above components, the following materials can be added to the composition of the present invention in an amount of up to 50% by mass in the active light curable composition depending on the application.

  For coating paints and adhesives such as printing inks, cans, plastics, paper, and wood, inorganic fillers, softeners, antioxidants, anti-aging agents, stabilizers, tackifier resins, leveling agents, antifoaming agents Inactive ingredients such as plasticizers, dyes, treating agents, viscosity modifiers, organic solvents, lubricity-imparting agents and UV-blocking agents can be blended. Examples of inorganic fillers include, for example, zinc oxide, aluminum oxide, antimony oxide, calcium oxide, chromium oxide, tin oxide, titanium oxide, iron oxide, copper oxide, lead oxide, bismuth oxide, magnesium oxide and manganese oxide. Metal / non-metal oxides, hydroxides such as aluminum hydroxide, ferrous hydroxide and calcium hydroxide, salts such as calcium carbonate and calcium sulfate, silicon compounds such as silicon dioxide, kaolin, bentonite, clay and talc Natural pigments, natural zeolite, minerals such as Oya stone, natural mica and ionite, synthetic inorganic materials such as artificial mica and synthetic zeolite, and various metals such as aluminum, iron and zinc. Some of these may overlap with the pigment, but these may be added to the composition as a filler, if necessary, in addition to the essential pigment. The lubricity-imparting agent is blended for the purpose of improving the lubricity of the resulting coating film. For example, a fatty acid ester wax, silicon wax, fluorine wax, polyolefin, which is an esterified product of a polyol compound and a fatty acid. Mention may be made of waxes such as waxes, animal waxes and plant waxes. Examples of the tackifying resin include rosins such as rosin acid, polymerized rosin acid and rosin acid ester, terpene resin, terpene phenol resin, aromatic hydrocarbon resin, aliphatic saturated hydrocarbon resin, and petroleum resin.

  As a specific aspect of the present invention, it can be used for various printing such as an ultraviolet curable ink jet printer (particularly a line head system), flexographic printing, stencil printing, gravure printing, offset printing, varnish coating, and the like. This is particularly effective when the platen has a drum shape. In particular, when multi-color simultaneous printing is effective.

Example 1
(Preparation of energy ray curable ink)
After mixing and stirring the ink compositions described in Table 1, the obtained liquid was filtered with a filter to obtain inks 1 to 8. In Table 1, a numerical value represents a mass part.

  The following printing experiments were performed using inks 1 to 4 and changing the number of colors used.

In the flexographic printing type energy beam curable composition curing apparatus of FIG. 2, irradiation was performed at 80 mJ / cm ² using Vzero manufactured by Integration. Adjust the distance of the light source closest to the reaction part and the light source to 1.5mm, and use the black colored stainless steel fiber for the light shielding part 8, the width is the whole width direction of the irradiation part, the length is the media transport A 10 mm brush was attached to the rear end of the irradiation unit. The media was made using art paper.

Density Stability Evaluation The solid density and density unevenness after continuous printing for 2 hours were compared 5 minutes after starting printing and 2 hours after printing. The color measurement of each of the above colors is a colorimeter (spectrolino manufactured by Gretag Macbeth).
keywizard) was carried out under the following conditions.

Light source: D50
Field of view: 2 ° field of view Density: ANSI T
White standard: abs
Filter: No-filter
○: Between samples after 5 minutes and 2 hours, concentration difference within sample is less than ± 0.05 Δ: Between samples after 5 minutes and 2 hours, maximum difference within sample within ± 0.05, Less than 15 x: between samples after 5 minutes and 2 hours, maximum concentration difference within sample ± 0.15 or more The results are shown in Table 2.

  By providing the light shielding part 8 from Table 2, density stability was obtained. Similar effects were obtained when similar experiments were performed using inks 5-8.

Example 2
Using a 200W power source as a light source, a low-pressure mercury lamp (NIPPO's custom-made product), PET (poly-
The same experiment as in Example 1 was performed using inks 5 to 8 using ethyl terephthalate. The same evaluation as in Example 1 was performed and the results shown in Table 3 were obtained.

  From Table 3, it can be seen that the same effect can be obtained even if the light source is changed. When inks 1 to 4 were used, they were not cured sufficiently.

Example 3
In the ink jet type energy beam curable composition curing apparatus of FIG. 1, the head gap h2 and the irradiation part, and the platen gap h1 are set to 1.5 mm, and the outer side of the irradiation part 4 and the front side and the rear side not shown. The brush-like light shielding member of the material used in Example 1 was attached. Irradiation was performed at 80 mJ / cm ² using Vzero manufactured by Integration. The light shielding property was evaluated with a UV label (S) manufactured by NOF Corporation. The installation confirmed a light shielding property of 100 times or more.

  For this reason, the leakage light of ultraviolet rays is significantly reduced, and the amount of unnecessary exposure to the worker is reduced.

It is a front view which shows an example of a structure of the principal part used with a serial printing system with the inkjet energy-beam curable composition hardening | curing apparatus which can be used by this invention. It is a front view which shows an example of a structure of the principal part of the energy beam curable composition hardening | curing apparatus of the flexographic printing system which can be used by this invention. It is a front view explaining the irradiation part of the energy beam curable composition hardening | curing apparatus of the flexographic printing system which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Energy beam curable composition hardening | curing apparatus 2 Head carriage 3, 19 Recording head 4, 24 Irradiation part 5 Platen part 6 Guide member 7 Bellows structure 8 Light-shielding part 10 Feeding roll 11 Take-up roll 12 Plate cylinder 13 Anix roll 14 Doctor blade 15 Ink reservoir 16, 17 Roller 41 Light source 42 Light control plate 43 Protection plate P Base material

Claims (4)

In the energy beam curable composition curing apparatus, the energy beam curable composition for curing the energy beam curable composition by irradiating the energy beam after applying a coating liquid containing the energy beam curable composition to the substrate. The product curing device has an energy beam curable composition application unit and an energy beam irradiation unit, and relatively moves the substrate from the energy beam curable composition application unit in the direction of the energy beam irradiation unit. An energy beam curable composition curing apparatus, comprising: a drive unit that causes the light beam irradiation unit to have a light shielding unit made of a flexible material at the most downstream portion of the energy beam irradiation unit. The energy ray-curable composition curing device according to claim 1, wherein the flexible material is fibrous and brush-shaped. The energy beam curable composition curing apparatus according to claim 1, wherein the energy beam curable composition applying unit and the energy beam irradiation unit are provided around a drum-shaped platen. The energy beam curable composition curing device according to any one of claims 1 to 3 is at least one selected from an inkjet printer, a flexographic printer, a gravure printer, and a lithographic printer. An energy ray curable composition curing device.

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