JP6885227B2 - Clear ink composition - Google Patents

Description

The present invention relates to an active photocurable composition containing a nonionic surfactant, a photocurable monomer and a photopolymerization initiator, and an ink composition containing the active photocurable composition.

Conventionally, active photocurable compositions that are cured by active energy rays such as ultraviolet rays and electron beams have been used as paints, coating agents, adhesives, printing inks, and inks used for plastics, paper, glass, woodwork, inorganic materials, and the like. It has been put to practical use in various applications such as a receiving layer, a printed circuit board, and electrical insulation. In particular, the active ray-curable ink is attracting attention because it can record on a material having poor quick-drying property and ink absorption.

The nonionic surfactant used in such an active photocurable composition has not only solubility in a photocurable monomer, but also wettability to the above-mentioned materials and scratch prevention property of a coating film. Antifouling properties against oil-based markers and the like are required. For clear inks that require transparency (used for printing topcoats, etc.), the transparency of the solution may be required.

For example, in the field of inkjet inks, specific polymerizable compounds, photopolymerization initiators, and HLBs are 5 to 12 in JP-A-2012-167161 (Patent Document 1) and JP-A-2003-147233 (Patent Document 2). Alternatively, an ultraviolet curable ink composition containing 5.0 to 7.5 polyether-modified silicone oils is disclosed. Further, in Japanese Patent Application Laid-Open No. 2006-045549 (Patent Document 3), a radiation-curable type containing an alkali metal salt, an alkylene oxide-added nonionic surfactant, (meth) acrylate and / or (meth) acryloyl group-containing oligomer. Compositions have been proposed.

However, there is room for improvement in terms of wettability and antifouling property to materials having poor ink absorption such as polyethylene terephthalate (PET) and polyvinyl chloride (PVC).

Japanese Unexamined Patent Publication No. 2012-167161 Japanese Unexamined Patent Publication No. 2003-147233 Japanese Unexamined Patent Publication No. 2006-045549

The present invention has been made in view of the above circumstances, and is a nonionic surfactant exhibiting excellent solubility in photopolymerizable monomers and photopolymerizable oligomers and excellent wettability to materials having poor ink absorption. An object of the present invention is to provide an active photocurable composition and an ink composition containing the same, which can impart scratch resistance to a dry coating film and antifouling property to an oil-based marker or the like. To do.

As a result of diligent studies to achieve the above object, the present inventor has a nonionic surfactant specific to an active photocurable composition containing a photocurable monomer and / or an oligomer and a photopolymerizable initiator. By blending a predetermined amount of the agent, it is possible to exhibit wettability to a material having poor ink absorption such as PET and PVC, excellent scratch prevention property when formed into a coating film, and antifouling property against oil-based markers and the like. It was possible, and in particular, it was found that high transparency can be exhibited when used in a clear ink, and the present invention has been made.

［式（１）中、ｍ１は１０以上の整数、ｎ１は１以上の整数であり、Ｒ¹は、炭素数が１〜２０のアルキル基、炭素数が１〜２０のヒドロキシ基含有アルキル基、炭素数が１〜２０のカルボキシル基含有アルキル基、又は下記式（２）で示される基を表す。］

［上記式（２）中、Ｒ²は水素原子又は炭素数１〜５のアルキル基、ａは１〜２０の数、ｂは０〜５０の数である。また、（Ｃ₂Ｈ₄Ｏ）単位及び（Ｃ₃Ｈ₆Ｏ）単位はその順序を問わず、ランダムであってもブロックであってもよい。］
（Ｂ）光硬化性モノマー及び／又はオリゴマーと、
（Ｃ）光重合性開始剤と、
を含有し、上記（Ａ）成分の含有量が０．１〜３．０質量％であり、且つ、上記（Ｂ）成分の含有量が５４〜９９質量％であり、（Ａ），（Ｂ）及び（Ｃ）成分の合計量が１００質量％であることを特徴とするクリアインク組成物。
２．上記（Ａ）成分の式（１）のＲ¹の少なくとも１個が、上記式（２）で示される基である上記１記載のクリアインク組成物。
３．上記（Ａ）成分の非イオン性界面活性剤が、上記式（１）中のｎ１が１〜５である上記１又は２記載のクリアインク組成物。
４．（Ｂ）光硬化性モノマー及び／又はオリゴマーが、単官能アクリレート、２官能アクリレート、多官能アクリレート、単官能メタクリレート、２官能メタクリレート、多官能メタクリレート、ウレタンアクリレート、及びこれらのオリゴマーから選ばれる少なくとも１種である上記１〜３のいずれかに記載のクリアインク組成物。
５．（Ｃ）光重合性開始剤が、１−ヒドロキシ−シクロヘキシル−フェニル−ケトン、ビス（２，４，６−トリメチルベンゾイル）−フェニルフォスフィンオキサイド、２−ヒドロキシ−２−メチル−１−フェニル−プロパン−１−オン、１−［４−（２−ヒドロキシエトキシ）−フェニル］−２−ヒドロキシ−２−メチル−１−プロパン−１−オン、２−ヒドロキシ−１−｛４−［４−（２−ヒドロキシ−２−メチル−プロピオニル）−ベンジル］フェニル｝−２−メチル−プロパン−１−オンの群から選ばれる少なくとも１種である上記１〜４のいずれかに記載のクリアインク組成物。
６．上記（Ｂ）成分は、トリメチロールプロパントリアクリレート、１，６−ヘキサンジオールジアクリレート、又はトリメチロールプロパントリアクリレートのオリゴマーである上記１〜５のいずれかに記載のクリアインク組成物。
７．上記低吸収性被記録媒体が、表面に油性インクを受容するための塗工層が設けられた塗工紙である上記１〜６のいずれかに記載のクリアインク組成物。
８．上記非吸収性被記録媒体が、インク吸収層を有していないプラスチックフィルム、又はプラスチックがコーティングされた紙である上記１〜６のいずれかに記載のクリアインク組成物。
９．上記低吸収性被記録媒体が、アート紙、コート紙及びマット紙の群から選ばれる塗工紙である上記７記載のクリアインク組成物。
１０．上記非吸収性被記録媒体が、インク吸収層を有していないプラスチックフィルムであって、該プラスチックが、ポリ塩化ビニル（ＰＶＣ）、ポリエチレンテレフタレート（ＰＥＴ）、ポリカーボネート、ポリスチレン、ポリウレタン、ポリエチレン及びポリプロピレン（ＰＰ）の群から選ばれるものである上記８記載のクリアインク組成物。 Therefore, the present invention provides the following clear ink composition.
1. 1. A clear ink composition applied to a low-absorbency recording medium or a non-absorbent recording medium, wherein the clear ink composition is used.
(A) A nonionic surfactant having an HLB of 1.7 or more and less than 5 represented by the following formula (1).

Wherein (1), m1 is an integer of 10 or more, n1 is an integer of 1 or more, R ¹ is a hydroxy group-containing alkyl group of the alkyl group having 1 to 20 carbon atoms, having 1 to 20 carbon atoms, It represents a carboxyl group-containing alkyl group having 1 to 20 carbon atoms or a group represented by the following formula (2). ]

[In the above formula (2), R ² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a is a number of 1 to 20, and b is a number of 0 to 50. Further, the (C ₂ H ₄ O) unit and the (C ₃ H ₆ O) unit may be random or block regardless of the order. ]
(B) With photocurable monomers and / or oligomers,
(C) Photopolymerizable initiator and
The content of the component (A) is 0.1 to 3.0% by mass, and the content of the component (B) is 54 to 99% by mass. A clear ink composition, wherein the total amount of the components () and (C) is 100% by mass.
2. The clear ink composition according to 1 above, wherein at least one ^{of R 1} of the formula (1) of the component (A) is a group represented by the formula (2).
3. 3. The clear ink composition according to 1 or 2 above, wherein the nonionic surfactant of the component (A) is n1 in the formula (1) of 1 to 5.
4. (B) The photocurable monomer and / or oligomer is at least one selected from monofunctional acrylate, bifunctional acrylate, polyfunctional acrylate, monofunctional methacrylate, bifunctional methacrylate, polyfunctional methacrylate, urethane acrylate, and oligomers thereof. The clear ink composition according to any one of 1 to 3 above.
5. (C) The photopolymerizable initiator is 1-hydroxy-cyclohexyl-phenyl-ketone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propane. -1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1- {4- [4- (2) The clear ink composition according to any one of 1 to 4 above, which is at least one selected from the group of -hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1-one.
6. The clear ink composition according to any one of 1 to 5 above, wherein the component (B) is an oligomer of trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, or trimethylolpropane triacrylate.
7. The clear ink composition according to any one of 1 to 6 above, wherein the low-absorbency recording medium is a coated paper provided with a coating layer for receiving oil-based ink on the surface.
8. The clear ink composition according to any one of 1 to 6 above, wherein the non-absorbent recording medium is a plastic film having no ink absorbing layer or paper coated with plastic.
9. The clear ink composition according to 7 above, wherein the low-absorbency recording medium is a coated paper selected from the group of art paper, coated paper, and matte paper.
10. The non-absorbent recording medium is a plastic film having no ink absorbing layer, and the plastics are polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate, polystyrene, polyurethane, polyethylene and polypropylene ( The clear ink composition according to 8 above, which is selected from the group of PP).

The active photocurable composition of the present invention and an ink composition containing the same have wettability to a material having poor ink absorbency, excellent scratch resistance when formed into a coating film, and antifouling property against oil-based markers and the like. And so on. Further, when used in an ink composition for clear ink, high transparency can be imparted.

The active photocurable composition of the present invention comprises (A) a nonionic surfactant having an HLB of less than 5 represented by the following formula (1), (B) a photocurable monomer and / or an oligomer, and (C. ) It contains a photopolymerizable initiator.

The component (A) is a nonionic surfactant represented by the following formula (1).

In the above formula (1), m1 is an integer of 10 or more, n1 is an integer of 1 or more, and R ¹ is an alkyl group having 1 to 20 carbon atoms, a hydroxy group-containing alkyl group having 1 to 20 carbon atoms, and a carbon number of carbon atoms. Represents 1 to 20 carboxyl group-containing alkyl groups or groups represented by the following formula (2).

In the above formula (2), R ² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a is a number of 1 to 20, and b is a number of 0 to 50. Further, the (C ₂ H ₄ O) unit and the (C ₃ H ₆ O) unit may be random or block regardless of the order.

In the above formula (1), when m1 is an integer of 10 or more, it is possible to improve the wettability of the active photocurable composition to the substrate, the friction coefficient of the cured film, the antifouling property against oil-based markers, and the like. it can. Further, m1 is preferably an integer of 20 to 60, more preferably an integer of 20 to 40.

Further, in the above formula (1), n1 is an integer of 1 or more, preferably an integer of 1 to 5, and more preferably an integer of 1 to 3. When n1 is 0, the wettability of the active photocurable composition to the substrate, the friction coefficient of the cured film, the antifouling property against oil-based markers, etc. may not be sufficiently exhibited.

^{As R 1} of the above formula (1), it is preferable that at least one of them, more preferably all of them, is a group represented by the formula (2). In this case, when the ^{group represented by the above formula (2) is adopted as R 1} of the above formula (1), the values of a and b in the formula are a = 1 to 20, b = 0 to 50. In particular, it is desirable that a = 1 to 16, b = 0 to 30. If the value of a or b deviates from the above range, the wettability of the active photocurable composition to the substrate, the coefficient of friction of the cured film, the antifouling property against oil-based markers, etc. may not be sufficiently exhibited. ..

The HLB of the component (A) is less than 5.0, but when the HLB is in the range of 0 to 5.0, the larger the HLB value, the more the component (B) is dissolved in the photocurable monomer and / or the oligomer. It is preferably 1.0 or more, and more preferably 3.0 or more because of its excellent properties.

Here, the HLB (hydrophilic group / hydrophobic group balance “Hydrophile-Lipophile Balance”) is defined by the following formula (3) (Griffin method). HLB takes a value from 0 to 20, and the closer it is to 0, the higher the lipophilicity, and the closer it is to 20, the higher the hydrophilicity.

In calculating the HLB of the nonionic surfactant represented by the above formula (1), the hydrophilic moiety corresponds to the (C ₂ H ₄ ^{O) unit of R 1} , a hydroxy group, and a carboxyl group.

The content of the component (A) is 0.01 to 5.0% by mass, preferably 0.1 to 3.0% by mass, and more preferably 0 in 100% by mass of the active photocurable composition. .5 to 2.0% by mass. If the content of the component (A) exceeds 5.0% by mass, the foaming property becomes large, and there is a possibility that printing or coating defects due to bubbles may occur.

When a colorant is used, the content of the component (A) with respect to the colorant is preferably 0.2 to 100% by mass, more preferably 1 to 100% by mass.

(B) The photocurable monomer and / or oligomer is a monomer and / or oligomer that can be polymerized and cured by light having a characteristic wavelength. As the component (B), a component that is polymerized and cured by ultraviolet rays is particularly preferable.

The photocurable monomer and / or oligomer (B) may be radically polymerizable, cationically polymerizable, or anionically polymerizable, but is preferably radically polymerizable. Such (B) photocurable monomer and / or oligomer is selected from the group of monofunctional acrylate, bifunctional acrylate, polyfunctional acrylate, monofunctional methacrylate, bifunctional methacrylate, polyfunctional methacrylate and urethane acrylate. It is preferably a seed or two or more kinds of monomers. Specifically, 2-hydroxy-3-acryloyloxypropyl methacrylate, polyethylene glycol diacrylate, propoxylated ethoxylated bisphenol A diacrylate, 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene, Tricyclodecanedimethanol diacrylate, 1,10-decanediol diacrylate, 1,6-hexanediol diacrylate (HDDA), 1,9-nonanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate ( TPGDA), polytetramethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, ethoxylated bisphenol A dimethacrylate, tricyclodecanedimethanol dimethacrylate, 1,10-decane Didioldimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, neopentyl glycol dimethacrylate, ethoxylated polypropylene glycol dimethacrylate, glycerin dimethacrylate, polypropylene glycol dimethacrylate, ethoxylated isocyanuric acid triacrylate , Ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate, pentaerythritol triacrylate, trimethylolpropantriacrylate (TMPTA), ditrimethylolpropanetetraacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, di Examples thereof include pentaerythritol polyacrylate, dipentaerythritol hexaacrylate, and trimethyl propantrimethacrylate. Further, it may be an oligomer of these monomers. In this case, the oligomer generally has a degree of polymerization of 10 to 100.

The content of the photocurable monomer and / or oligomer (B) is preferably 54 to 99% by mass, more preferably 56 to 93% by mass, based on 100% by mass of the active photocurable composition. If the above content is less than 54% by mass, there may be a problem that the resin does not cure, and if it exceeds 99% by mass, the wettability to the material, the scratch prevention property of the coating film, the prevention against oil-based markers, etc. may occur. Dirt may be insufficient.

(C) The photopolymerization initiator generates an active species by irradiation with light of a characteristic wavelength, and (II) a photoradical polymerization initiator and a photocation depending on the type of photocurable monomer and / or oligomer. A suitable one can be selected from the polymerization initiator and the photoanionic polymerization initiator. In particular, it is preferable to use a photoradical polymerization initiator that generates radicals by ultraviolet rays. Examples of such a photopolymerization initiator include an alkylphenone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, an intramolecular hydrogen abstraction type photopolymerization initiator, and an oxime ester-based photopolymerization initiator. Of these, alkylphenone-based photopolymerization initiators are preferable, specifically 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, and bis (2,4). 6-trimethylbenzoyl) -phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2- Methyl-1-propan-1-one, 2-hydroxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1-one, 2 -Methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) ) -2-[(4-Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone and the like. More preferably, it is an α-hydroxyalkylphenone-based photopolymerization initiator, 1-hydroxy-cyclohexyl-phenyl-ketone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-hydroxy-2-. Methyl-1-phenyl-propane-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{ 4- [4- (2-Hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one is preferred. Examples of commercially available products include IRUGACURE 184,819, 1173, 2959, 127 manufactured by BASF.

The (C) photopolymerizable initiator is preferably contained in an amount of 1 part by mass or more, more preferably 1 to 10 parts by mass, when the total amount of the (B) photocurable monomer and / or oligomer is 100 parts by mass. It is a department. If this content is less than 1 part by mass, the active photocurable composition may not be cured.

The active photocurable composition of the present invention may contain a colorant to be a colored ink composition, or may be a clear ink composition. As the colorant, dyes, organic pigments and inorganic pigments can be preferably used. For example, as dyes, colorants classified into oil-soluble dyes and basic dyes in addition to those classified as acidic dyes, direct dyes, reactive dyes, virgin dyes, sulfur dyes or food dyes in the color index. Can also be used. Further, as a pigment, for black ink, carbon black (CI pigment black 7) such as furnace black (color black), lamp black, acetylene black, channel black, etc., specifically, for example, Rayvan ( Raven) 7000, Rayvan 5750, Rayvan 5250, Rayvan 5000, Rayvan 3500, Rayvan 2000, Rayvan 1500, Rayvan 1250, Rayvan 1200, Rayvan 1190 ULTRA-II, Rayvan 1170, Rayvan 1255 (above, made by Columbia), Black Pearls (Black) Pearls L, Legal 400R, Legal 330R, Legal 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monac 900, Monac 1000, Monac 1100, Monac 1300, Monac 1400, Vulcan (Valcan) XC-72R (above, manufactured by Cabot), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (manufactured by Degussa), No. 25, No. 33, No. 40, No. 47, No. 52, No. 900, No. 2300, MCF-88, MA600, MA7, MA8, MA100 (all manufactured by Mitsubishi Chemical Corporation), etc., or metals such as copper oxide, iron oxide (CI pigment black 11), titanium oxide, aniline black Examples thereof include organic pigments such as (CI Pigment Black 1). Further, for color inks, C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 12 (Disazo Yellow AAA), 13, 14, 17, 24, 34, 35, 37, 42 (Yellow Iron Oxide), 53, 55, 74, 81, 83 (Disazo Yellow) Yellow HR), 93, 94, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 153, 180, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 2 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B (Ca)), 48 : 3 (Permanent Red 2B (Sr)), 48: 4 (Permanent Red 2B (Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81 (Rhodamine 6G Lake), 83, 88, 101 (Bengara), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 202, 206, 209, 219, C.I. I. Pigment Violet 19, 23, C.I. I. Pigment Orange 36, C.I. I. Pigment Blue 1, 2, 15 (Pphthalocyanine Blue R), 15: 1, 15: 2, 15: 3 (Pphthalocyanine Blue G), 15: 4, 15: 6 (Parthalocyanine Blue E), 16, 17: 1, 56 , 60, 63, C.I. I. Pigment Greens 1, 4, 7, 8, 10, 17, 18, 36 and the like can be used.

In the active photocurable composition of the present invention, for example, each of the above components can be obtained by a known mixing preparation method such as a propeller type stirrer. Further, the components that are solid at room temperature can be mixed by heating if necessary.

A resin or other additives may be added to the active photocurable composition of the present invention, if necessary. The resin is a polymer having a hydrophobic group and a hydrophilic group, and it is preferable that the hydrophobic group of the substance forming the polymer is at least one selected from an alkyl group, a cycloalkyl group or an aryl group. .. The hydrophilic group is preferably at least a carboxyl group, a sulfonic acid group, a hydroxyl group, an amino group, an amide group, or a base thereof. As specific examples of the substances forming these dispersed polymers, monomers and oligomers having an acryloyl group, a methacryloyl group, a vinyl group or an aryl group having a double bond can be used. For example, styrene, tetrahydrofurfuryl acrylate, butyl methacrylate, (α, 2,3 or 4) -alkylstyrene, (α,2,3 or 4) -alkoxystyrene, 3,4-dimethylstyrene, α-phenylstyrene, Divinylbenzene, vinylnaphthalene, dimethylamino (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropylacrylamide, N, N-dimethylaminoethyl acrylate, acryloylmorpholine, N, N-dimethylacrylamide, N-isopropylacrylamide , N, N-diethylacrylamide, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, ethylhexyl (meth) acrylate, other alkyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxy group, propoxy Group, butoxy group diethylene glycol or polyethylene glycol (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobonyl (meth) acrylate, hydroxyalkyl (meth) acrylate, and other fluorine-containing When introducing a crosslinked structure in addition to monofunctionals such as chlorine-containing, silicon-containing (meth) acrylate, (meth) acrylamide, maleic acid amide, and (meth) acrylic acid (mono, di, tri, tetra, poly) (Meta) acrylates such as ethylene glycol di (meth) acrylate, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol and 1,10-decanediol, tri. Methylolpropan tri (meth) acrylate, glycerin (di, tri) (meth) acrylate, di (meth) acrylate of ethylene oxide adduct of bisphenol A or F, neopentyl glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate. , Dipentaerythritol hexa (meth) acrylate and other compounds having an acrylic group or a methacrylic group can be used.

The blending amount of the above resin is not particularly limited, but is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, based on 100% by mass of the active photocurable composition. When the resin is blended, it is preferably 1% by mass or more.

As other additives, an ultraviolet absorber, an antioxidant, a pH adjuster, a preservative, a viscosity adjuster and the like can be appropriately blended. These additives can be blended as the balance in 100% by weight of the active photocurable composition.

The active photocurable composition preferably has a viscosity (23 ° C.) of 100 mPa · s or less (excluding 0), which may lead to excellent printability.

The active photocurable composition of the present invention is suitable for applications such as paints, printing inks, and ink receiving layers used for plastics, paper, glass, woodworking, inorganic materials, and the like.

The active photocurable composition of the present invention is obtained by applying the present composition on a substrate, a spin coating method, a (doctor) knife coating method, a micro gravure coating method, a direct gravure coating method, an offset gravure method, a reverse gravure method, and a reverse. Examples thereof include a method of applying by a roll coating method, a (Meyer) bar coating method, a die coating method, a spray coating method, a dip coating method and the like, and curing the composition by irradiating with ultraviolet rays or electron beams. As the irradiation conditions, for example, when ultraviolet rays are adopted, the irradiation intensity ^{is preferably 150 to 1,000 mJ / cm 2} , and the irradiation time is preferably 1 to 300 seconds.

The ink composition containing the active photocurable composition of the present invention is printed on a recording medium, and is particularly preferably used for coating a low-absorbency recording medium or a non-absorbable recording medium. be able to. The low-absorbency recording medium is not particularly limited, and examples thereof include coated paper provided with a coating layer on the surface for receiving oil-based ink. The coated paper is not particularly limited, and examples thereof include printed book paper typified by art paper, coated paper, and matte paper. The non-absorbent recording medium is not particularly limited, but for example, a plastic film having no ink absorbing layer, a base material typified by paper coated with plastic, or a plastic film adhered to the medium. Examples include those that are present. Examples of the plastic referred to here include polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene (PP) and the like.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

〔上記式（１）において、ｍ１＝１０、ｎ１＝１であり、Ｒ¹は下記式（２）で示される基を表す。〕

〔上記式（２）において、ａ＝５、ｂ＝０、Ｒ²＝Ｈを示す。〕 [Example 1]
(B-1) To 97.5% by mass of trimethylolpropane triacrylate, 0.5 of the nonionic surfactants (A-1) [HLB = 3.5] of the following formulas (1) and (2) 2.0% by mass and 2.0% by mass of (C-1) 1-hydroxy-cyclohexyl-phenyl-ketone were added to obtain an active photocurable composition (clear ink composition).

[In the above formula (1), m1 = 10, n1 = 1, and R ¹ represents a group represented by the following formula (2). ]

[In the above formula (2), a = 5, b = 0, R ² = H are shown. ]

[Examples 2 to 7]
Similar to Example 1, using (A-1) to (A-5), (B-1) to (B-3), (C-1), and (C-2) shown below, An active photocurable composition (clear ink composition) was obtained with the compositions shown in Table 1.

(A) Nonionic surfactant (A-1): In the above formulas (1) and (2), m1 = 10, n1 = 1, a = 5, b = 0, R ² = H. Nonionic surfactant [HLB = 3.5]
(A-2): In the above formulas (1) and (2), the nonionic surfactant [HLB =] in which ^{m1 = 30, n1 = 2, a = 8, b = 0 and R 2 = H.} 4.2]
(A-3): In the above formulas (1) and (2), the nonionic surfactant [HLB =] in which ^{m1 = 60, n1 = 5, a = 17, b = 30 and R 2 = H.} 4.7]
(A-4): In the above formulas (1) and (2), a nonionic surfactant having ^{m1 = 60, n1 = 5, a = 16, b = 30 and R 2} = C ₂ H _5. [HLB = 4.4]
(A-5): In the above formulas (1) and (2), the nonionic surfactant [HLB =] in which ^{m1 = 60, n1 = 1, a = 6, b = 0 and R 2 = H.} 1.7]
(A'-1): In the above formulas (1) and (2), the nonionic surfactant [HLB] in which ^{m1 = 9, n1 = 6, a = 2, b = 0 and R 2 = H.} = 5.1]

(B) Photocurable Monomer and / or Oligomer (B-1) Trimethylolpropane Triacrylate (B-2) 1,6-Hexanediol Diacrylate (HDDA)
(B-3) Oligomer of trimethylolpropane triacrylate (TMPTA) (degree of polymerization 50)

(C) Photopolymerizable Initiator (C-1) 1-Hydroxy-Cyclohexyl-Phenyl-Ketone (C-2) Bis (2,4,6-trimethylbenzoyl) -Phenylphosphine oxide

[ Reference Example 8]
(B-1) To 95.5% by mass of trimethylolpropane triacrylate, m1 = 10, n1 = 1, a = 5, b = 0, R ² = H in the formulas (1) and (2). 0.5% by mass of nonionic surfactant (A-1) [HLB = 3.5], 2.0% by mass of (C-1) 1-hydroxy-cyclohexyl-phenyl-ketone, magenta pigment (C) I. Pigment Red 122) was added in an amount of 2.0% by mass to obtain an ink composition.

[ Reference Examples 9 to 21]
Similar to Reference Example 8, (A-1) to (A-5), (B-1) to (B-3), (C-1), (C-2), magenta pigment (CI). Pigment Red 122) or cyan pigment (CI Pigment Blue 15: 3) was used to obtain ink compositions with the compositions shown in Tables 1 and 2.

[Comparative Examples 1 to 7]
Active photocurable compositions and ink compositions were prepared with the compositions shown in Table 2. In Comparative Examples 1 to 3, as shown in Table 2, m1 = 9, n1 = in the above (A'-1) "formulas (1) and (2)" as nonionic surfactants. 6, a = 2, b = 0 and R ² = H nonionic surfactant [HLB = 5.1] ”was used.

The following evaluations were made on the active photocurable compositions or ink compositions prepared in Examples 1 to 7 , Reference Examples 8 to 21, and Comparative Examples 1 to 7. The results are shown in Tables 1 and 2.

(1) Monomer contact angle The contact angle value of the active photocurable composition or ink composition after 0.3 seconds on OK top-coated paper, PET, and PVC is measured by the contact angle meter CA-D type manufactured by Kyowa Interface Science Co., Ltd. Was measured using.

(2) Dynamic friction coefficient An active light-curable composition or an ink composition was applied to a PET film (manufactured by Cosmo Shine Co., Ltd.) with a bar coater # 10, and irradiated with UV (365 nm) for 2 minutes. The coefficient of dynamic friction of the film was measured using a surface measuring machine HEIDON Type: 38 manufactured by Shinto Kagaku Co., Ltd. The smaller the coefficient of kinetic friction, the higher the scratch prevention property.

(3) Static Friction Coefficient The active photocurable coating composition was applied to a PET film (manufactured by Cosmo Shine Co., Ltd.) with a bar coater # 10, and was irradiated with UV (365 nm) for 2 minutes. The coefficient of static friction of the film was measured using a surface measuring machine HEIDON Type: 38 manufactured by Shinto Kagaku Co., Ltd. The smaller the coefficient of static friction, the higher the scratch prevention property.

(4) Antifouling property The active photocurable coating composition was applied to a PET film (manufactured by Cosmo Shine Co., Ltd.) with a bar coater # 10, and was irradiated with UV (365 nm) for 2 minutes. A spiral was drawn on the film with an oil-based marker (black / extra-fine / round core made by Platinum Pen Co., Ltd.), and the work of erasing by rubbing the spiral with gauze was repeated, and the number of times it could be erased was measured.

(5) Solubility of Nonionic Surfactant in Photopolymerizable Monomer and Photopolymerizable Oligomer After sufficiently stirring the compositions shown in Tables 1 and 2, the color difference / turbidity measuring device COH-400 (Nippon Denshoku Kogyo) (Evaluated only (clear ink composition) of Examples 1 to 7 and Comparative Examples 1, 4 and 5). If this value is less than 15.0 mg / l, it can be satisfactorily used as a clear ink.

Claims (10)

A clear ink composition applied to a low-absorbency recording medium or a non-absorbent recording medium, wherein the clear ink composition is used.
(A) A nonionic surfactant having an HLB of 1.7 or more and less than 5 represented by the following formula (1).

Wherein (1), m1 is an integer of 10 or more, n1 is an integer of 1 or more, R ¹ is a hydroxy group-containing alkyl group of the alkyl group having 1 to 20 carbon atoms, having 1 to 20 carbon atoms, It represents a carboxyl group-containing alkyl group having 1 to 20 carbon atoms or a group represented by the following formula (2). ]

[In the above formula (2), R ² is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, a is a number of 1 to 20, and b is a number of 0 to 50. Further, the (C ₂ H ₄ O) unit and the (C ₃ H ₆ O) unit may be random or block regardless of the order. ]
(B) With photocurable monomers and / or oligomers,
(C) Photopolymerizable initiator and
The content of the component (A) is 0.1 to 3.0% by mass, and the content of the component (B) is 54 to 99% by mass. A clear ink composition, wherein the total amount of the components () and (C) is 100% by mass. ^{The clear ink composition according to claim 1} , wherein at least one of R 1 of the formula (1) of the component (A) is a group represented by the formula (2). The clear ink composition according to claim 1 or 2, wherein the nonionic surfactant of the component (A) is n1 in the above formula (1) of 1 to 5. (B) The photocurable monomer and / or oligomer is at least one selected from monofunctional acrylate, bifunctional acrylate, polyfunctional acrylate, monofunctional methacrylate, bifunctional methacrylate, polyfunctional methacrylate, urethane acrylate, and oligomers thereof. The clear ink composition according to any one of claims 1 to 3. (C) The photopolymerizable initiator is 1-hydroxy-cyclohexyl-phenyl-ketone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propane. -1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1- {4- [4- (2) The clear ink composition according to any one of claims 1 to 4, which is at least one selected from the group of −hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1-one. .. The clear ink composition according to any one of claims 1 to 5, wherein the component (B) is an oligomer of trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, or trimethylolpropane triacrylate. The clear ink composition according to any one of claims 1 to 6, wherein the low-absorbency recording medium is a coated paper provided with a coating layer for receiving oil-based ink on the surface. The clear ink composition according to any one of claims 1 to 6, wherein the non-absorbent recording medium is a plastic film having no ink absorbing layer or paper coated with plastic. The clear ink composition according to claim 7, wherein the low-absorbency recording medium is a coated paper selected from the group of art paper, coated paper, and matte paper. The non-absorbent recording medium is a plastic film having no ink absorbing layer, and the plastics are polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate, polystyrene, polyurethane, polyethylene and polypropylene ( The clear ink composition according to claim 8, which is selected from the group of PP).