JP2009114235A - Ink composition and cured product using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active energy ray-curable ink composition having good adhesiveness, exhibiting good curability with low viscosity, and producing a cured product showing high hardness physical properties at a high elongation rate, and to provide the cured product. <P>SOLUTION: The active energy ray-curable ink composition comprises: a dendrimer having a radical polymerizable group and 2-6 functional groups; and a monomer having a ring structure. The active energy ray-curable ink composition is used for inkjet ink. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an active energy ray-curable ink composition having good adhesion, low viscosity and excellent curability, and a cured product having high hardness at a high stretch ratio.

  Conventionally, active energy ray-curable compositions have been supplied and used for offsets, silk screens, topcoats, etc., but there are advantages such as cost reduction by simplifying the drying process and reduction of solvent volatilization as an environmental response. In recent years, usage has increased. Among them, water-based and solvent-based inks are often used as ink-jet inks, and the use is properly used according to each feature, but for industrial use, there are limitations on the receiving substrate, relatively poor water resistance, There are problems such as high ink drying energy and adhesion of ink components to the head due to drying, and replacement with active energy ray-curable ink with relatively low volatility is expected.

  Polycarbonate is widely used as a material with high mechanical strength and good processability, and it is expected to develop ink compositions or ink cured products that combine adhesion to polycarbonate, stretch processing characteristics, and mechanical strength. ing.

  Use of a dendrimer is effective in order to suppress the ink jet ink to a low viscosity because of high curability. Documents 1 and 2 use a cationically curable dendrimer and describe a reduction in viscosity and improvement in curability. However, in general, the cationic curing system has a slower curing rate, and the radical curing system is superior in terms of the curing rate.

Further, in Documents 3 and 4, it is described that radical-curing dendrimers are used, and that storage stability and curability are improved by using the dendrimers. Properties and stretchability are not suitable for practical use.
JP 2004-99796 A JP 2006-282864 A JP 2007-182535 A JP 2007-182536 A

  An object of the present invention is to provide an active energy ray-curable ink composition and a printed matter having good adhesion, low viscosity and excellent curability, and a cured product exhibiting high hardness at a high stretch ratio.

  That is, the present invention relates to an active energy ray-curable ink composition comprising a dendrimer having a radically polymerizable group and having 2 to 6 functional groups and a monomer having a cyclic structure.

  Furthermore, this invention relates to said active energy ray hardening-type ink composition which is an inkjet ink composition.

  Furthermore, the present invention relates to a printed matter obtained by forming an image on a substrate with the above active energy ray hard inkjet ink and then curing the ink with an active energy ray.

  The present invention was able to provide an active energy ray-curable ink composition and printed matter having good adhesion, low viscosity and excellent curability, and the ink cured product exhibiting high hardness properties at a high stretch ratio.

  In general, the term dendrimer has been used for highly branched, highly regular multi-branched compounds. However, with the recent progress in research on synthetic methods for dendrimers, various highly branched compounds with low regularity have been developed as new dendrimers for the purpose of simplifying synthetic methods, such as the development of dendritic compounds by a one-step method. As for the nomenclature, there is no conclusion yet.

  Therefore, in the present invention, a dendrimer refers to a three-dimensionally branched multi-branched compound, and generically refers to a hyper-branched with low regularity and a dendrimer with high regularity. Such a dendrimer is composed of a core site, a branch site, a branch site, and a terminal site, as shown in FIG. FIG. 1 further shows a model diagram of the minimum dendrimer and standard dendrimer in the present invention, and the number of branches, the number of branch sites, the number of branch sites, and the number of terminal sites bound to the core site contained in each dendrimer. .

  In the present invention, the core part and the branch part have a structure in which at least three branches are bonded, and the branch part is a general term for constituent parts that connect one core part or branch part and an adjacent branch part or terminal part. The structure is not particularly limited, but is assumed to be composed of at least 4 atoms. Further, the number of branch sites present in one molecule of the dendrimer is at least 5, preferably 30-50.

  In general, in the case of a dendrimer with correct regularity, the size is represented by a concept term of generation. In the present invention, a branched structure starting from the above-defined core compound is referred to as a first generation dendrimer, and a structure having a branched structure branched from all terminal portions of the first generation is referred to as a second generation. FIG. 2 shows a third-generation dendrimer having a core part and a terminal part to which four branches are bonded, and each generation is shown in the figure. This is the definition of generation in the present invention.

  The dendrimer in the present invention is preferably a second generation or more, and more preferably a third generation to a fourth generation.

  The molecular weight of the dendrimer is preferably 500 to 50,000, and more preferably 500 to 10,000. When the molecular weight is lower than the above range, the cured film becomes brittle, and when the molecular weight is higher than the above range, the viscosity of the dendrimer becomes too high to be practical for use in ink.

  The radical polymerizable group in the present invention is not particularly limited as long as the end portion of the dendrimer has a radical polymerizable double bond, but is preferably an acrylic group having a high reaction rate.

  The number of functional groups at the terminal site having a radical polymerization group is preferably 2 to 6 functional groups. If it is monofunctional, a three-dimensional crosslinked structure cannot be formed and sufficient hardness cannot be obtained. Further, when a dendrimer having a large number of functional groups having 7 or more functional groups is used, the degree of freedom of molecules constituting the cured film is lost, and sufficient stretchability cannot be exhibited.

  In the present invention, the dendrimer is preferably from 0.01% by weight to 30% by weight, and more preferably from 0.01% by weight to 10% by weight. When there is more dendrimer than 30 weight%, adhesiveness will worsen.

  By using a dendrimer having 2 to 6 functional groups, the hardness is improved in a highly stretched region where the stretch ratio of the ink cured film is 150% or more, compared with a material not containing a dendrimer. Although the principle is not clear, it is considered that when a substance having a large molecular weight such as a dendrimer is included in the ink cured film, stress relaxation occurs inside the ink cured film and the hardness increases as film physical properties.

  Specific examples of the monomer having a monofunctional cyclic structure include cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, methylphenoxyethyl acrylate, 4-t-butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, tribromophenyl acrylate, Ethoxylated tribromophenyl acrylate, 2-phenoxyethyl acrylate (or its ethylene oxide and / or propylene oxide addition monomer), acryloylmorpholine, isobornyl acrylate, phenoxydiethylene glycol acrylate, vinyl caprolactam, vinyl pyrrolidone, 2-hydroxy-3 -Phenoxypropyl acrylate, 1,4-cyclohexane dimethyl Examples thereof include but are not limited to butanol monoacrylate and N-acryloyloxyethyl hexahydrophthalimide.

  Furthermore, among these monomers having high ink jet suitability, cyclohexyl acrylate, methylphenoxyethyl acrylate, 2-phenoxyethyl acrylate (or its ethylene oxide / propylene oxide addition monomer), isobornyl acrylate, vinyl caprolactam, vinyl pyrrolidone, 2-hydroxy-3-phenoxypropyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, and N-acryloyloxyethyl hexahydrophthalimide can be more preferably used.

  Furthermore, from the viewpoint of safety and coating film performance, methylphenoxyethyl acrylate, 2-phenoxyethyl acrylate (or its ethylene oxide alignment / propylene oxide addition monomer), isobornyl acrylate, vinyl caprolactam, 2-hydroxy- 3-phenoxypropyl acrylate and 1,4-cyclohexanedimethanol monoacrylate can be more preferably used. Further, 2-phenoxyethyl acrylate can be more suitably used from the viewpoint of stability. These compounds may be used alone or in combination of two or more as required.

  When these compounds having a cyclic structure are blended in the ink, the adhesion is improved. Although the principle is not clear, it is considered that the ring structure portion is in close contact with the base material on the surface, and the adhesion is improved by an increase in VanDer Waars force.

  The content of the monomer having a cyclic structure in the ink composition is desirably 60% by weight, and if it is less than that, the adhesion is deteriorated.

  As monomers having a bifunctional cyclic structure, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethoxylated 1,6 -Hexanediol diacrylate, neopentyl glycol di (meth) acrylate, polypropylene glycol diacrylate, 1,4-butanediol di (meth) acrylate, 1,9-nonanediol diacrylate, tetraethylene glycol diacrylate, 2-n -Butyl-2-ethyl-1,3-propanediol diacrylate, hydroxypivalate neopentyl glycol diacrylate, 1,3-butylene glycol di (meth) acrylate, ethoxylation Ripropylene glycol diacrylate, neopentyl glycol modified trimethylolpropane diacrylate, stearic acid modified pentaerythritol diacrylate, neopentyl glycol oligoacrylate, 1,4-butanediol oligoacrylate, 1,6-hexanediol oligoacrylate, ethoxylation Neopentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, bisphenol A diacrylate, dimethylol-tricyclodecane diacrylate, propoxylated bisphenol A di (meth) ) Acrylate, ethoxylated bisphenol A di (meth) acrylate, bisphenol F diacrylate, ethoxy Examples include, but are not limited to, bisphenol F diacrylate, propoxylated bisphenol F diacrylate, cyclohexane dimethanol di (meth) acrylate, dimethylol dicyclopentane diacrylate, isocyanuric acid diacrylate, propoxylated isocyanuric acid diacrylate, and the like. It is not a thing. These compounds may be used alone or in combination of two or more as required.

  Trimethylolpropane triacrylate, hydroxypivalic acid trimethylolpropane triacrylate, ethoxylated phosphoric acid triacrylate, pentaerythritol triacrylate, tetramethylolpropane triacrylate, tetramethylolmethane triacrylate, caprolactone as monomers having a trifunctional cyclic structure Modified trimethylolpropane triacrylate, propoxylate glyceryl triacrylate, trimethylolpropane oligoacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated isocyanuric acid triacrylate, tri (2-hydroxyethylisocyanate) Nurate) triacrylate, tri (meth) allylic Cyanurate, and the like but not limited thereto. These compounds may be used alone or in combination of two or more as required.

  Furthermore, a monomer having no cyclic structure can be used as necessary. Specific examples of monofunctional monomers having no cyclic structure include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, and 2-methoxyethyl acrylate. , Methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxyethoxyethyl acrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxydipropylene glycol acrylate, dipropylene glycol acrylate, β-carboxyl ethyl acrylate, ethyl Diglycol acrylate, trimethylolpropane formal monoacrylate DOO, imide acrylate, isoamyl acrylate, ethoxylated succinic acid acrylate, trifluoroethyl acrylate, .omega.-carboxypolycaprolactone monoacrylate, there may be mentioned N- vinylformamide, but not limited thereto.

  Specific examples of the polyfunctional monomer having no cyclic structure include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and 1,6-hexanediol di (meth). Acrylate, ethoxylated 1,6-hexanediol diacrylate, neopentyl glycol di (meth) acrylate, polypropylene glycol diacrylate, 1,4-butanediol di (meth) acrylate, 1,9-nonanediol diacrylate, tetraethylene Glycol diacrylate, 2-n-butyl-2-ethyl-1,3-propanediol diacrylate, neopentyl glycol diacrylate hydroxypivalate, 1,3-butylene glycol di (meth) acrylate , Trimethylolpropane triacrylate, hydroxypivalic acid trimethylolpropane triacrylate, ethoxylated phosphate triacrylate, ethoxylated tripropylene glycol diacrylate, neopentyl glycol modified trimethylolpropane diacrylate, stearic acid modified pentaerythritol diacrylate , Pentaerythritol triacrylate, tetramethylolpropane triacrylate, tetramethylol methane triacrylate, pentaerythritol tetraacrylate, caprolactone modified trimethylol propane triacrylate, propoxylate glyceryl triacrylate, tetramethylol methane tetraacrylate, pentaerythritol tetraacrylate, ditrimethylo Propane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, neopentyl glycol oligoacrylate, 1,4-butanediol oligoacrylate, 1,6 -Hexanediol oligoacrylate, trimethylolpropane oligoacrylate, pentaerythritol oligoacrylate, ethoxylated neopentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, ethoxylated Trimethylolpropane triacrylate, propoxylation Examples thereof include trimethylolpropane triacrylate, but are not limited thereto. These monofunctional and polyfunctional monomers may be used alone or in combination of two or more as required.

  In addition to the above, what is called an oligomer or a prepolymer can be used for the inkjet ink of the present invention. Specifically, “Ebecryl 230, 244, 245, 270, 280 / 15IB, 284, 285, 4830, 4835, 4858, 4883, 8402, 8803, 8800, 254, 264, 265, 294 / 35HD, manufactured by Daicel UCB, 1259, 1264, 4866, 9260, 8210, 1290.1290K, 5129, 2000, 2001, 2002, 2100, KRM7222, KRM7735, 4842, 210, 215, 4827, 4849, 6700, 6700-20T, 204, 205, 6602, 220, 4450, 770, IRR567, 81, 84, 83, 80, 657, 800, 805, 808, 810, 812, 1657, 1810, IRR302, 450, 670, 830, 835, 870, 1 30, 1870, 2870, IRR267, 813, IRR483, 811, 436, 438, 446, 505, 524, 525, 554W, 584, 586, 745, 767, 1701, 1755, 740 / 40TP, 600, 601, 604, 605, 607, 608, 609, 600 / 25TO, 616, 645, 648, 860, 1606, 1608, 1629, 1940, 2958, 2959, 3200, 3201, 3404, 3411, 3412, 3415, 3500, 3502, 3600, 3603, 3604, 3605, 3608, 3700, 3700-20H, 3700-20T, 3700-25R, 3701, 3701-20T, 3703, 3702, RDX63182, 6040, IRR419 ", manufactured by Sartomer CN104, CN120, CN124, CN136, CN151, CN2270, CN2271E, CN435, CN454, CN970, CN971, CN972, CN9782, CN981, CN9873, CN991, "Laromar EA81L, F87" manufactured by BASF LR8800, PE46T, LR8907, PO43F, PO77F, PE55F, LR8967, LR8981, LR8982, LR8992, LR9004, LR8956, LR8985, LR8987, UP35D, UA19T, LR9005, PO83F, PO33F, L8489, L9489 LR8996, LR9013 LR9019, PO9026V, PE9027V "manufactured by Cognis" Photomer 3005, 3015, 3016, 3072, 3982, 3215, 5010, 5429, 5430, 5432, 5662, 5806, 5930, 6008, 6010, 6019, 6184, 6210, 6217 6230, 6891, 6892, 6893-20R, 6363, 6572, 3660 "," Art Resin UN-9000HP, 9000PEP, 9200A, 7600, 5200, 1003, 1255, 3320HA, 3320HB, 3320HC, 3320HS, 901T, manufactured by Negami Kogyo Co., Ltd. 1200TPK, 6060PTM, 6060P "," Nippon Gosei Chemical Co., Ltd. "" purple light UV-6630B, 7000B, 7510B, 7461TE, 3000B, 320 " 0B, 3210EA, 3310B, 3500BA, 3520TL, 3700B, 6100B, 6640B, 1400B, 1700B, 6300B, 7550B, 7605B, 7610B, 7620EA, 7630B, 7640B, 2000B, 2010B, 2250EA, 2750B, “Kayarad” R-280, R-146, R131, R-205, EX2320, R190, R130, R-300, C-0011, TCR-1234, ZFR-1122, UX-2201, UX-2301, UX3204, UX-3301, UX-4101, UX-6101, UX-7101, MAX-5101, MAX-5100, MAX-3510, UX-4101 "and the like.

  The active energy ray described in the present invention affects an electron orbit of an irradiated object such as an electron beam, an ultraviolet ray, and an infrared ray, and indicates an energy ray that can trigger a polymerization reaction such as a radical, a cation, and an anion. The energy ray is not limited to this as long as it induces a polymerization reaction.

  The active energy ray-curable composition shown in the present invention refers to a liquid that is printed or coated on the surface of a substrate. This ink can be used as a coating application when it does not contain a coloring component, and can be used as a material for displaying graphics, characters, photographs, etc. when it contains a coloring component. Conventionally, dyes and pigments are widely used as the coloring component, but pigments are often used particularly from the viewpoint of weather resistance. As the pigment component, achromatic pigments such as carbon black, titanium oxide, calcium carbonate, or chromatic organic pigments can be used. Examples of organic pigments include insoluble azo pigments such as Toluidine Red, Toluidine Maroon, Hansa Yellow, Benzidine Yellow, and Pyrazolone Red, soluble azo pigments such as Ritol Red, Helio Bordeaux, Pigment Scarlet, and Permanent Red 2B, alizarin, indanthrone, and thioindigo. Derivatives from vat dyes such as maroon, phthalocyanine organic pigments such as phthalocyanine blue and phthalocyanine green, quinacridone organic pigments such as quinacridone red and quinacridone magenta, perylene organic pigments such as perylene red and perylene scarlet, isoindolinone yellow , Isoindolinone organic pigments such as isoindolinone orange, pyranthrone organic pigments such as pyranthrone red and pyranthrone orange, thioy Digo-based organic pigments, condensed azo-based organic pigments, benzimidazolone-based organic pigments, quinophthalone-based organic pigments such as quinophthalone yellow, isoindoline-based organic pigments such as isoindoline yellow, and other pigments such as flavanthrone yellow and acylamide yellow Nickel azo yellow, copper azomethine yellow, perinone orange, anthrone orange, dianthraquinonyl red, dioxazine violet and the like.

  When organic pigments are exemplified by color index (CI) numbers, CI Pigment Yellow 12, 13, 14, 17, 20, 24, 74, 83, 8893, 109, 110, 117, 120, 125, 128, 129, 137 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185, CI Pigment Orange 16, 36, 43, 51, 55, 59, 61, CI Pigment Red 9, 48 49, 52, 53, 57, 97, 122, 123, 149, 168, 177, 180, 192, 202, 206, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240 , CI Pigment Violet 19, 23, 29, 30, 37, 40, 50, CI Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 22, 60, 64, C.I. Pigment Green 7, 36, C.I. Pigment Brown 23, 25, 26, and the like.

  Specific examples of carbon black include “Special Black 350, 250, 100, 550, 5, 4, 4A, 6” “Printex U, V, 140 U, 140 V, 95, 90, 85, 80, 75, 55, manufactured by Degussa. 45, 40, P, 60, L6, L, 300, 30, 3, 35, 25, A, G ", Cabot's" REGAL 400R, 660R, 330R, 250R "," MOGUL E, L ", Mitsubishi Chemical “MA7, 8, 11, 77, 100, 100R, 100S, 220, 230” “# 2700, # 2650, # 2600, # 200, # 2350, # 2300, # 2200, # 1000, # 990, # 980, # 970, # 960, # 950, # 900, # 850, # 750, # 650, # 52, # 50, # 47, # 45, # 4 5L, # 44, # 40, # 33, # 332, # 30, # 25, # 20, # 10, # 5, CF9, # 95, # 260 ”and the like.

  Specific examples of titanium oxide include “Taipeku CR-50, 50-2, 57, 80, 90, 93, 95, 953, 97, 60, 60-2, 63, 67, 58, 58- manufactured by Ishihara Sangyo Co., Ltd. 2, 85 "" Tipekes R-820, 830, 930, 550, 630, 680, 670, 580, 780, 780-2, 850, 855 "," Tipekes A-100, 220 "," Tipekes W-10 "," Tipekes " PF-740, 744 "" TTO-55 (A), 55 (B), 55 (C), 55 (D), 55 (S), 55 (N), 51 (A), 51 (C) " "TTO-S-1, 2", "TTO-M-1, 2", "Titanics JR-301, 403, 405, 600A, 605, 600E, 603, 805, 806, 701, 800, 808" manufactured by Teika "Titanic EN-1, C, 3, 4, 5 ", DuPont" Taipyua R-900,902,960,706,931 ", and the like.

  Among the above pigments, quinacridone organic pigments, phthalocyanine organic pigments, benzimidazolone organic pigments, isoindolinone organic pigments, condensed azo organic pigments, quinophthalone organic pigments, isoindoline organic pigments, etc. are light-resistant. Is preferable because it is excellent. The organic pigment is preferably a fine pigment having an average particle diameter of 10 to 150 nm as measured by laser scattering. When the average particle diameter of the pigment is less than 10 nm, the light resistance is lowered due to the small particle diameter, and when it exceeds 150 nm, it is difficult to maintain stable dispersion, and the pigment is likely to precipitate.

  The organic pigment can be refined by the following method. That is, a mixture comprising at least three components of an organic pigment, a water-soluble inorganic salt that is 3 times by weight or more of the organic pigment, and a water-soluble solvent is made into a clay-like mixture, and is kneaded strongly with a kneader or the like and then refined. And stir with a high speed mixer or the like to form a slurry. Next, filtration and washing of the slurry are repeated to remove the water-soluble inorganic salt and the water-soluble solvent. In the miniaturization step, a resin, a pigment dispersant, or the like may be added.

  Examples of the water-soluble inorganic salt include sodium chloride and potassium chloride. These inorganic salts are used in the range of 3 times by weight or more, preferably 20 times by weight or less of the organic pigment. When the amount of the inorganic salt is less than 3 times by weight, a treated pigment having a desired size cannot be obtained. On the other hand, if the amount is more than 20 times by weight, the washing process in the subsequent step is great, and the substantial amount of the organic pigment is reduced.

  The water-soluble solvent is an organic solvent and a water-soluble inorganic salt that is used as a crushing aid, and is used for efficient crushing efficiently, especially if it is a solvent that dissolves in water. Although not limited, a high boiling point solvent having a boiling point of 120 to 250 ° C. is preferable from the viewpoint of safety because the temperature rises during kneading and the solvent is easily evaporated. Examples of water-soluble solvents include 2- (methoxymethoxy) ethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether , Triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, low molecular weight Examples thereof include polypropylene glycol.

  In the present invention, the pigment is preferably contained in the composition in the range of 3 to 30% by weight in order to obtain a sufficient concentration and sufficient light resistance.

  In the present invention, it is preferable to add a pigment dispersant in order to improve the dispersibility of the pigment and the storage stability of the ink. Examples of the pigment dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a salt of a long chain polyaminoamide and a polar acid ester, a high molecular weight unsaturated acid ester, Polymer copolymer, modified polyurethane, modified polyacrylate, polyether ester type anionic activator, naphthalene sulfonic acid formalin condensate salt, aromatic sulfonic acid formalin condensate salt, polyoxyethylene alkyl phosphate ester, polyoxyethylene Nonylphenyl ether, stearylamine acetate, etc. can be used.

  Specific examples of the dispersant include “Anti-Terra-U (polyaminoamide phosphate)”, “Anti-Terra-203 / 204 (high molecular weight polycarboxylate)”, “Disperbyk-101” (polyamino) manufactured by BYK Chemie. Amide phosphate and acid ester), 107 (hydroxyl group-containing carboxylic acid ester), 110, 111 (copolymer containing acid group), 130 (polyamide), 161, 162, 163, 164, 165, 166, 170 (high Molecular copolymer) ”,“ 400 ”,“ Bykumen ”(high molecular weight unsaturated acid ester),“ BYK-P104, P105 (high molecular weight unsaturated acid polycarboxylic acid) ”,“ P104S, 240S (high molecular weight unsaturated) Acid polycarboxylic acid and silicon) "," Lactimon (long-chain amine and unsaturated acid polycarbonate) Rubonic acid and silicon).

  Also, “Efka CHEMICALS” “Efka 44, 46, 47, 48, 49, 54, 63, 64, 65, 66, 71, 701, 764, 766”, “Efka Polymer 100 (modified polyacrylate), 150 (aliphatic) System modified polymer), 400, 401, 402, 403, 450, 451, 452, 453 (modified polyacrylate), 745 (copper phthalocyanine system) "," Floren TG-710 (urethane oligomer) "," Flownon "manufactured by Kyoeisha Chemical Co., Ltd. “SH-290, SP-1000”, “Polyflow No. 50E, No. 300 (acrylic copolymer)”, “Disparon KS-860, 873SN, 874 (polymer dispersing agent), # 2150 (manufactured by Enomoto Kasei Co., Ltd.) Aliphatic polyvalent carboxylic acid), # 7004 (polyether ester type) ” The

Further, “Demol RN, N (Naphthalenesulfonic acid formalin condensate sodium salt), MS, C, SN-B (aromatic sulfonic acid formalin condensate sodium salt), EP”, “Homogenol L-18 (poly) Carboxylic acid type polymer), “Emulgen 920, 930, 931, 935, 950, 985 (polyoxyethylene nonylphenyl ether)”, “Acetamine 24 (coconut amine acetate), 86 (stearyl amine acetate)”, “Abisia” Solspers 5000 (phthalocyanine ammonium salt type), 13940 (polyesteramine type), 17000 (fatty acid amine type), 24000GR, 32000, 33000, 39000, 41000, 53000 ", Nikko Chemical's" Nikkor T106 (polyoxy) Chile Nso sorbitan monooleate), MYS-IEX (polyoxyethylene monostearate), Hexagline4-0 (hexa glyceryl Rute Huwei rate) ", Ajinomoto Fine-Techno Co., Ltd." Ajisper PB821,822,824 ", and the like.
The dispersant is preferably contained in the composition in an amount of 0.1 to 10% by weight.

  In order to further improve the dispersibility of the pigment and the storage stability of the ink, it is preferable to add an acidic derivative of an organic pigment to the composition of the present invention when the pigment is dispersed.

In order to improve the wettability to the substrate, it is preferable to add a surface conditioner to the composition of the present invention. Specific examples of the surface conditioner include BYK-300, 302, 306, 307, 310, 315, 320, 322, 323, 325, 330, 331, 333, 337, 340, 344, 370, and 375 manufactured by BYK-Chemie. 377, 350, 352, 354, 355, 356, 358N, 361N, 357, 390, 392, UV3500, UV3510, UV3570, “Tegorad-2100, 2200, 2250, 2500, 2700” manufactured by Tego Chemie. These surface conditioners may be used alone or in combination of two or more as required.
The surface conditioner is preferably contained in the composition in an amount of 0.001 to 1% by weight.

  In the present invention, when ultraviolet rays are used as active energy rays, a radical photopolymerization initiator is blended in the ink. As the radical photopolymerization initiator, those of molecular cleavage type or hydrogen abstraction type are suitable for the present invention. Specific examples include benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, benzyl, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) -butan-1-one, bis (2,4,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 1,2-octanedione, 1- (4- (phenylthio) -2,2- (O-benzoyloxime)), oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone, etc. are preferably used, and further molecular cleavage other than these As types, 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether , Benzyldimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one and 2-methyl-1- (4-Methylthiophenyl) -2-morpholinopropan-1-one or the like may be used in combination, and further, a hydrogen abstraction type photopolymerization initiator, benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl- 4'-methyl-diphenyl sulfide and the like can also be used in combination.

  In the present invention, the composition containing oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide has a good curing rate. It has an effect to obtain a blocking-free printed matter.

  Usually, a photopolymerization initiator often has one cleavage part. However, since the photopolymerization initiator used in the present invention has two or more cleavage parts, after cleavage by active energy irradiation, a polymerizable monomer and Since it can react in a plurality of parts, the molecular weight of the polymerization reaction product in the cured film can be increased. The blocking is considered to be caused by a large amount of unreacted monomers and dimers and trimers that have been polymerized in a low molecular state in the cured film. For this reason, a blocking-free printed matter can be obtained by using a photopolymerization initiator having two or more cleavage sites as the photopolymerization initiator and increasing the molecular weight of the polymerization reaction product in the cured film.

  The photopolymerization initiator is classified into an intramolecular bond cleavage type and an intermolecular hydrogen abstraction type, and the oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone of the present invention. Is classified into an acetophenone system that occupies most of the intramolecular bond type, and has characteristics such as faster polymerization, less yellowing due to photo-oxidation, and better storage stability than the intermolecular hydrogen abstraction type. 2,4,6-Trimethylbenzoyldiphenylphosphine oxide has an absorption peak in the wavelength range of 350 nm to 395 nm and is oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone. By using the light on the longer wavelength side than the light absorbed by the light, the penetration depth of the irradiation light becomes longer, so that the curing inside the film is promoted. As a result of using a photopolymerization initiator having an absorption peak, the curing rate was improved.

  For the photo radical polymerization initiator, as sensitizers, for example, trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N, An amine that does not cause an addition reaction with the polymerizable component, such as N-dimethylbenzylamine and 4,4′-bis (diethylamino) benzophenone, can also be used in combination. Of course, it is preferable to select and use the radical photopolymerization initiator and the sensitizer, which are excellent in solubility in the ultraviolet curable compound and do not inhibit the ultraviolet transmittance.

  The photopolymerization initiator is preferably contained in an amount of 2 to 20% by weight based on the polymerizable monomer. If it is less than 2% by weight, the curing rate is remarkably deteriorated, and if it is more than 20% by weight, the curing rate does not change from that of 10% by weight, and a dissolution residue may occur. Even if the undissolved residue is melted, there is a problem that the viscosity of the ink is increased and the inkjet dischargeability is deteriorated.

  The absorption spectrum of the photopolymerization initiator was measured by a spectrophotometer (HITACHI U-3300) using a 1 cm quartz cell after dissolving the photopolymerization initiator in acetonitrile by 0.1% by weight. The absorption peak described in the present invention means a peak having an absorbance of 0.5 or more under the above measurement conditions. In addition, the acylphosphine oxide photopolymerization initiator often has an absorption peak with an intensity of 0.5 or more in the wavelength range of 350 nm to 395 nm under the above measurement conditions.

  The composition of the present invention includes a polymerization inhibitor such as hydroquinone, p-methoxyphenol, t-butylcatechol, pyrogallol, butylhydroxytoluene, etc., in order to enhance stability over time and on-machine stability in the recording apparatus. Is preferably blended in the ink in an amount of 0.01 to 5% by weight.

  The composition of the present invention can use various additives such as a plasticizer, a surface conditioner, an ultraviolet light inhibitor, a light stabilizer, and an antioxidant.

  The ink-jet ink of the present invention is produced by well dispersing a pigment together with a monomer and a pigment dispersant using an ordinary dispersing machine such as a sand mill. It is preferable to prepare a concentrated solution having a high pigment concentration in advance and dilute with a monomer. Sufficient dispersion is possible even with dispersion by a normal disperser. Therefore, excessive dispersion energy is not required, and a large amount of dispersion time is not required. An ink having excellent properties is prepared. The ink is preferably filtered through a filter having a pore size of 3 μm or less, and more preferably 1 μm or less.

  The inkjet ink of the present invention is preferably adjusted to have a high viscosity at 25 ° C. of 5 to 50 mPa · s. An ink having a viscosity of 5 to 50 mPa · s at 25 ° C. exhibits stable ejection characteristics, particularly from a head having a normal frequency of 4 to 10 KHz to a head having a high frequency of 10 to 50 KHz.

  When the viscosity is less than 5 mPa · s, a decrease in the follow-up property of the discharge is recognized in the high-frequency head. When the viscosity exceeds 50 mPa · s, even if a mechanism for reducing the viscosity by heating is incorporated in the head, the discharge itself A drop occurs, the ejection stability becomes poor, and the ejection cannot be performed at all.

  The ink-jet ink of the present invention preferably has an electric conductivity of 10 μS / cm or less in the piezo head and does not cause electrical corrosion inside the head. Further, in the continuous type, it is necessary to adjust the electric conductivity by the electrolyte. In this case, it is necessary to adjust the electric conductivity to 0.5 mS / cm or more.

  In order to use the ink-jet ink of the present invention, first, the ink-jet ink is supplied to a printer head of a printer for an ink-jet recording system, discharged from the printer head onto a substrate, and then an active energy ray such as an ultraviolet ray or an electron beam is applied. Irradiate. This quickly cures the composition on the print medium.

  In addition, as a light source of an active energy ray, when irradiating an ultraviolet-ray, a high pressure mercury lamp, a metal halide lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet laser, and sunlight can be used, for example. When cured with an electron beam, it is usually cured with an electron beam having an energy of 300 eV or less, but it can also be cured instantaneously with an irradiation dose of 1 to 5 Mrad. When irradiating with ultraviolet rays, it is preferable to use an A bulb from Integration Technology as a UV lamp. The UV lamp is an improved metal halide lamp, has a strong emission spectrum in the short wavelength region (250 nm to 300 nm) and the long wavelength region (320 nm to 390 nm), and cures a coating film having a large film thickness and a large surface area. It is suitable for. In particular, in the case of inkjet, the curing rate is dramatically improved by using the UV lamp.

[Example]
The present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples, “part” represents “part by weight”.

First, Pigment Dispersion A was prepared with the following composition. Hereinafter, a dispersion was prepared by adding a pigment and a dispersant to a monomer, stirring the mixture with a high-speed mixer or the like until uniform, and then dispersing the obtained mill base with a horizontal sand mill for about 1 hour.
・ Special Black 350 (Degussa carbon black pigment) 30 parts ・ Solspers 32000 (Lubrisol pigment dispersion) 6 parts ・ Phenoxyethyl acrylate 64 parts

Examples 1-8
The pigment dispersion A was converted into an ink according to the formulation shown in Table 1, and after stirring for 2 hours, it was confirmed that there was no dissolution residue, filtered with a membrane filter to remove coarse particles, and an active energy ray curable composition. I got a thing. This active energy ray-curable composition was printed and cured on a polycarbonate plate so as to have a film thickness of 10 μm to obtain a coating film.
Examples 9-16
Inks were prepared as described in Table 2 in the same manner as in Examples 1 to 8, and printing and curing were performed.
Comparative Examples 1-9
Inks were prepared as described in Table 3 in the same manner as in Examples 1 to 16, and printing and curing were performed.

The hardness of the coating film after curing was measured using a hardness tester (Fischerscope HM 2000: manufactured by Fischer Instruments Co., Ltd.) under a load of 3.0 N / mm ² and no creep. did.
×: 4.5 N / mm less than ² △: less than 4.5 N / mm ² or more ^{6.0N / mm 2 ○: 6.0N /} mm 2 or more 7.5 N / mm less than ² ◎: adhesion to 7.5 N / mm ² or more substrates Apply the cellophane tape to the part where the cured coating is cross-cut into 100 squares at intervals of 1 mm, rub it with an eraser from the top surface, and adhere the cellophane tape to the coated surface sufficiently. Judging from the degree of adhesion of the coating film to the substrate when peeled at a temperature. Moreover, the case where cross-cutting was not performed was also evaluated.

X: Peeled with or without cross-cut.
Δ: Less than 50% remaining with cross cut, and does not peel off without cross cut.
○: 50% or more remains with cross cut, and does not peel off without cross cut.
(Double-circle): It does not peel at all with and without crosscut.

  The coating film on the obtained polycarbonate was punched into a dumbbell shape together with the substrate using a punching machine (manufactured by Dumbbell), and the obtained test piece was heated to 170 ° C. using Tensilon (UCT-1T: manufactured by ORIENTEC). The sample was heated and a tensile test was performed on the whole substrate at a strain rate of 2 / min. Since the breaking point of the coating film was difficult to grasp from the change in tension obtained from the load cell, the elongation at the time when the breaking of the coating film surface was visually confirmed was expressed as%.

×: Less than 50% Δ: 50% or more and less than 100% ○: 100% or more and less than 150% ◎: 150% or more

In Examples 1-16, the 2-6 functional dendrimer is used, and as is clear from Table 1 and Table 2, it is excellent in adhesiveness and has reproduced the high draw ratio. Furthermore, it has hardness even in a highly stretched region of 150% or more.
In Comparative Examples 1 to 3 using a 15-functional dendrimer, the stretchability is poor.
In Comparative Examples 4 to 7 that do not contain a dendrimer but are composed of a monomer having a cyclic structure, good adhesion to polycarbonate is exhibited, but the hardness is lower than that containing a dendrimer.

  Furthermore, in Comparative Example 8, which has a dendrimer but hardly contains a monomer having a cyclic structure, the adhesion to the polycarbonate is poor. Further, Comparative Example 9 containing no dendrimer and almost no monomer having a cyclic structure is inferior in hardness, adhesion and stretchability.

Dendrimer model diagram Dendrimer model diagram

Claims (3)

  An active energy ray-curable ink composition comprising a dendrimer having a radical polymerizable group and having 2 to 6 functional groups and a monomer having a cyclic structure.   2. The energy ray curable ink composition according to claim 1, which is used for inkjet ink.   A printed matter obtained by printing with an ink using the active energy ray-curable ink composition according to claim 1.

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