JP6590302B2 - Ultraviolet curable inkjet composition and container - Google Patents

Description

  The present invention relates to an ultraviolet curable inkjet composition and a container.

  The ink jet recording method is capable of recording high-definition images with a relatively simple device, and has been rapidly developed in various fields. Among these, various studies have been made on ink compositions used in an ink jet recording method in which ink is cured by irradiation with ultraviolet rays. For example, Patent Document 1 discloses an ultraviolet curable inkjet ink that can be stably and accurately ejected, has excellent storage stability, and has excellent curability. A UV curable inkjet ink containing a high-valent dispersant, a polymerizable compound, and a photopolymerization initiator, wherein the total amount of cationic impurities, metal impurities and strongly acidic substances is 500 ppm or less, and the water content is 1 to An ink-jet ink characterized by 3% by weight is described.

JP 2005-200560 A

  However, when the water content in the ultraviolet curable inkjet composition is 1 to 3% by mass as in Patent Document 1, pigment aggregation may occur and foreign matter (pigment aggregate) may occur. Moreover, when the moisture content in a composition is high, the sclerosis | hardenability of an inkjet composition may also fall. In order to suppress the precipitation of foreign substances and improve the curability, it is conceivable to reduce the amount of water in the ultraviolet curable inkjet composition as much as possible. However, excessive reduction in the amount of water requires an excessive amount of time and time to remove moisture from the polymerizable compound, resulting in efficiency in producing an ultraviolet curable ink jet composition. The nature will decline.

  The present invention has been made to solve at least a part of the above-described problems, and is excellent in curability, can suppress the precipitation of foreign matters, has excellent storage stability, and has high production efficiency. An object of the present invention is to provide a type ink jet composition and a container filled with the composition.

  The present inventors diligently studied to solve the above problems. As a result, the above problem can be solved by defining the acid value and amine value of the pigment dispersant contained in the ultraviolet curable inkjet composition and the amount of water contained in the composition within a certain range. As a result, the present invention has been completed.

That is, the present invention is as follows.
[1]
An ultraviolet curable inkjet composition containing a pigment, a pigment dispersant, a polymerizable compound, and a photopolymerization initiator, and contained in a container,
The water content is 0.05% by mass or more and 1.0% by mass or less with respect to the total amount of the ultraviolet curable ink jet composition, and the acid value and amine value of the pigment dispersant are both 50 mgKOH / g or less. An ultraviolet curable inkjet composition, at least one of which is 10 mgKOH / g or more.
[2]
The ultraviolet curable inkjet composition according to [1], wherein the total amount of the acid value and amine value of the pigment dispersant is 15 mgKOH / g or more and 90 mgKOH / g or less.
[3]
The ultraviolet curable inkjet composition according to [1] or [2], which contains a radical polymerizable compound as the polymerizable compound.
[4]
The ultraviolet curable inkjet composition according to any one of [1] to [3], which contains an acylphosphine oxide compound as the photopolymerization initiator.
[5]
The ultraviolet curable inkjet composition according to any one of [1] to [4], which contains a polymerizable compound having a vinyl ether group and a (meth) acrylate group as the polymerizable compound.
[6]
The ultraviolet curable inkjet composition according to [5], wherein the polymerizable compound having a vinyl ether group and a (meth) acrylate group is contained in an amount of 10 to 70% by mass based on the total amount of the ultraviolet curable composition.
[7]
As a polymerizable compound having the vinyl ether group and the (meth) acrylate group, the following general formula (1):
_{^{CH 2 = CR 1 -COOR 2 -O}} -CH = CH-R 3 ··· (1)
Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a divalent organic residue having 2 to 20 carbon atoms, and R ³ is a hydrogen atom or a monovalent organic residue having 1 to 11 carbon atoms. Group.)
The ultraviolet curable inkjet composition according to [5] or [6], comprising a vinyl ether group-containing (meth) acrylic acid ester represented by:
[8]
The ultraviolet curable ink jet composition according to [7], wherein the vinyl ether group-containing (meth) acrylic acid ester is 2- (vinyloxyethoxy) ethyl acrylate.
[9]
[1] A container containing the ultraviolet curable inkjet composition according to any one of [8].
[10]
The container includes the ultraviolet curable inkjet composition in a container made of a member having an oxygen permeability of 0.01 cc to 5.0 cc · 20 μm / (m ² · day · atm) at 23 ° C. and 65% humidity. Or a container filled with at least the ultraviolet ray curable ink jet composition is 0.01 cc to 5.0 cc · 20 μm / (m ² · m at 23 ° C. and 65% humidity. The container according to [9], wherein the container is sealed with a package made of a member of day / atm).

It is a disassembled perspective view which shows an example of the container of this invention.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to this, Various modifications are possible without departing from the scope of the invention. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, positional relationships such as up, down, left and right are based on the positional relationships shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto, and “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto.

[UV curable inkjet composition]
The ultraviolet curable composition of this embodiment contains a pigment, a pigment dispersant, a polymerizable compound, a photopolymerization initiator, and moisture, and is contained in a container. The water content contained therein is 0.05% by mass or more and 1.0% by mass or less with respect to the total amount of the ultraviolet curable composition. The acid value and amine value of the pigment dispersant are both 50 mg KOH / g or less, and at least one is 10 mg KOH / g or more. The UV curable composition is preferably a radical polymerization type UV curable composition from the viewpoint of further improving the curability and from the viewpoint of obtaining high versatility and high simplicity.

  In the ultraviolet curable composition, both the acid value and the amine value of the pigment dispersant are 50 mg KOH / g or less, and the water content in the ultraviolet curable composition is 1.0 mass% or less. It is possible to suppress the precipitation of. This is because when there is a large amount of water, it is considered that foreign matter is precipitated when there is a pigment dispersant having an acid value or an amine value. By making the acid value and amine value of the water and the pigment dispersant below a predetermined amount, This is presumed to be because the precipitation of foreign matter is suppressed. Further, when at least one of the acid value and the amine value of the pigment dispersant is 10 mg KOH / g or more, the curability of the ultraviolet curable composition can be made more satisfactory. This is presumably because the pigment dispersant having such oxidation or amine value effectively acts as a catalyst for the curing reaction of the polymerizable compound. Furthermore, the manufacturing efficiency of an ultraviolet curable composition can be improved by making the moisture content in an ultraviolet curable composition 0.05 mass% or more. In particular, the amount of water in the ultraviolet curable composition is highly dependent on the amount of water present (mixed) in the synthesized polymerizable compound. It is speculated that the load based on the process of reducing the amount of water present in the polymerizable compound can be reduced. As a result, the manufacturing time can be shortened, the process can be simplified and the labor can be reduced, and the manufacturing cost can be reduced. However, the factors are not limited to these.

  The ultraviolet curable composition can be used for various applications, and the application is not limited. Applications include, for example, for ink and polymerization molding. Among these, from the viewpoint of more effectively and reliably achieving the effects of the present invention, it is preferably used for ink, and is also preferably used for inkjet. Hereinafter, the ultraviolet curable composition of the present embodiment is used as an inkjet ink composition (hereinafter also simply referred to as “composition”) which is an embodiment of an inkjet composition (composition used by being ejected by an inkjet method). Although the case where it uses is demonstrated in detail, an ultraviolet curable composition is not limited to this.

(Polymerizable compound)
The composition contains a polymerizable compound. The polymerizable compound can be polymerized alone or by application of energy such as light irradiation by the action of a polymerization initiator to cure the composition on the recording medium. Although it does not specifically limit as a polymeric compound, A conventionally well-known monofunctional, bifunctional, and trifunctional or more polyfunctional monomer and oligomer can be used. A polymeric compound may be used individually by 1 type, and may be used in combination of 2 or more type. Hereinafter, these polymerizable compounds will be exemplified.

  The polymerizable compound preferably contains a radically polymerizable compound from the viewpoint of further increasing the curability of the composition and from the viewpoint of obtaining high versatility and high simplicity. In addition to or in place of it, the polymerizable compound increases the curability, further lowers the viscosity of the composition, and enhances the solubility of the polymerization initiator when a polymerization initiator is used. It is preferable to contain a polymerizable compound having a (meth) acrylate group. The polymerizable compound having a vinyl ether group and a (meth) acrylate group is preferably a radical polymerizable compound having a vinyl ether group and a (meth) acrylate group. Examples of such a polymerizable compound include (meth) acrylates having a monofunctional or polyfunctional vinyl ether group, and these are preferable from the same viewpoint as described above.

The monofunctional (meth) acrylate having a vinyl ether group is not particularly limited, but from the viewpoints of lowering the viscosity of the composition, having a high flash point, and further improving the curability of the composition, the following general formula (1) :
_{^{CH 2 = CR 1 -COOR 2 -O}} -CH = CH-R 3 ··· (1)
It is preferable to contain the vinyl ether group containing (meth) acrylic acid ester represented by these. Here, in formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is a divalent organic residue having 2 to 20 carbon atoms, and R ³ is a hydrogen atom or having 1 to 11 carbon atoms. It is a monovalent organic residue.

  Examples of the vinyl ether group-containing (meth) acrylic acid ester represented by the general formula (1) include 2-vinyloxyethyl (meth) acrylate, 3-vinyloxypropyl (meth) acrylate, and (meth) acrylic acid. 1-methyl-2-vinyloxyethyl, 2-vinyloxypropyl (meth) acrylate, 4-vinyloxybutyl (meth) acrylate, 1-methyl-3-vinyloxypropyl (meth) acrylate, (meth) acrylic acid 1- Vinyloxymethylpropyl, 2-methyl-3-vinyloxypropyl (meth) acrylate, 1,1-dimethyl-2-vinyloxyethyl (meth) acrylate, 3-vinyloxybutyl (meth) acrylate, (meth) acrylic acid 1 -Methyl-2-vinyloxypropyl, 2-vinyloxybutyl (meth) acrylate, (meth) a 4-vinyloxycyclohexyl silylate, 6-vinyloxyhexyl (meth) acrylate, 4-vinyloxymethylcyclohexylmethyl (meth) acrylate, 3-vinyloxymethylcyclohexylmethyl (meth) acrylate, (meth) acrylic acid 2-vinyloxymethylcyclohexylmethyl, p-vinyloxymethylphenylmethyl (meth) acrylate, m-vinyloxymethylphenylmethyl (meth) acrylate, o-vinyloxymethylphenylmethyl (meth) acrylate, (meth) 2- (vinyloxyethoxy) ethyl acrylate, 2- (vinyloxyisopropoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxy) propyl (meth) acrylate, 2- (vinyloxy) (meth) acrylate Ethoxy) isopropyl, (meth) acrylic acid 2- Vinyloxyisopropoxy) propyl, 2- (vinyloxyisopropoxy) isopropyl (meth) acrylate, 2- (vinyloxyethoxyethoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyisopropoxy) (meth) acrylate ) Ethyl, 2- (vinyloxyisopropoxyethoxy) ethyl (meth) acrylate, 2- (vinyloxyisopropoxyisopropoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyethoxy) propyl (meth) acrylate 2- (vinyloxyethoxyisopropoxy) propyl (meth) acrylate, 2- (vinyloxyisopropoxyethoxy) propyl (meth) acrylate, 2- (vinyloxyisopropoxyisopropoxy) propyl (meth) acrylate, (Meth) acrylic acid 2- (vinylo) Xylethoxyethoxy) isopropyl, (meth) acrylic acid 2- (vinyloxyethoxyisopropoxy) isopropyl, (meth) acrylic acid 2- (vinyloxyisopropoxyethoxy) isopropyl, (meth) acrylic acid 2- (vinyloxyisopropoxy) Isopropoxy) isopropyl, 2- (vinyloxyethoxyethoxyethoxy) ethyl (meth) acrylate and 2- (vinyloxyethoxyethoxyethoxyethoxy) ethyl (meth) acrylate. These are used singly or in combination of two or more.

  Among these, from the same viewpoint as described above, 2- (vinyloxyethoxy) ethyl (meth) acrylate, that is, 2- (vinyloxyethoxy) ethyl acrylate and 2- (vinyloxyethoxy) ethyl methacrylate At least one of them is preferable, and 2- (vinyloxyethoxy) ethyl acrylate is more preferable. Since both 2- (vinyloxyethoxy) ethyl acrylate and 2- (vinyloxyethoxy) ethyl methacrylate have a simple structure and a small molecular weight, the viscosity of the composition can be significantly reduced. Examples of 2- (vinyloxyethoxy) ethyl (meth) acrylate include 2- (2-vinyloxyethoxy) ethyl (meth) acrylate and 2- (1-vinyloxyethoxy) ethyl (meth) acrylate. Examples of 2- (vinyloxyethoxy) ethyl acrylate include 2- (2-vinyloxyethoxy) ethyl acrylate and 2- (1-vinyloxyethoxy) ethyl acrylate. Incidentally, 2- (vinyloxyethoxy) ethyl acrylate is superior in terms of curability compared to 2- (vinyloxyethoxy) ethyl methacrylate.

  The content of the polymerizable compound having a vinyl ether group and a (meth) acrylate group is preferably 10 to 70% by mass, more preferably 10 to 60% by mass with respect to the total amount (100% by mass) of the composition. -50 mass% is still more preferable. When the content is 10% by mass or more, the viscosity of the composition can be reduced, and the curability of the composition tends to be more excellent. On the other hand, when the content is 70% by mass or less, the composition has excellent storage stability and tends to have excellent surface gloss of the printed material.

  The composition may contain one or two or more monofunctional, bifunctional, and trifunctional or higher polyfunctional monomers other than those exemplified above. Examples of such monomers include, but are not limited to, unsaturated carboxylic acids of (meth) acrylic acid, itaconic acid, crotonic acid, isocrotonic acid and maleic acid; salts of the unsaturated carboxylic acids; unsaturated carboxylic acids Esters, urethanes, amides and anhydrides; acrylonitrile, styrene, various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes.

  Monofunctional, bifunctional, and trifunctional or higher polyfunctional oligomers are not particularly limited. For example, oligomers formed from the above monomers such as linear acrylic oligomers, epoxy (meth) acrylates, oxetane (meth) Examples include acrylates, aliphatic urethane (meth) acrylates, aromatic urethane (meth) acrylates, and polyester (meth) acrylates.

  Moreover, an N-vinyl compound may be included as another monofunctional monomer or polyfunctional monomer. The N-vinyl compound is not particularly limited, and examples thereof include N-vinylformamide, N-vinylcarbazole, N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, and derivatives thereof. It is done.

  The composition may contain a monofunctional (meth) acrylate as a monofunctional monomer. In this case, the composition has a low viscosity, is excellent in solubility of the photopolymerization initiator and other additives, and is easy to be ejected during ink jet recording. Although it does not specifically limit as monofunctional (meth) acrylate, For example, isoamyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, isomyristyl (meta) ) Acrylate, isostearyl (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate, 2-hydroxybutyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate , Methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, tetra Drofurfuryl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, lactone-modified flexibility (meta ) Acrylate, t-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2- (isopropenoxyethoxy) ethyl (meth) acrylate, 2- (isopropeno) Xyloxyethoxy) ethyl (meth) acrylate, 2- (isopropenoxyethoxyethoxyethoxy) ethyl (meth) acrylate, 2- (isopropenoxyethoxyethoxyethoxyethoxy) ethyl ( Data) acrylate, polyethylene glycol monovinyl ether (meth) acrylate, and polypropylene glycol monovinyl ether (meth) acrylate and the like. Among these, phenoxyethyl (meth) acrylate is preferable.

  10-60 mass% is preferable with respect to the whole quantity (100 mass%) of a composition, and, as for content of a monofunctional monomer, 20-50 mass% is more preferable. By setting it as the said preferable range, it exists in the tendency which is excellent with sclerosis | hardenability, initiator solubility, storage stability, and discharge stability.

  The composition may contain a polyfunctional (meth) acrylate as a polyfunctional monomer. Among them, the bifunctional (meth) acrylate is not particularly limited. For example, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) ) Acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol Di (meth) acrylate, neopentylglycol di (meth) acrylate, dimethylol-tricyclodecane di (meth) acrylate, EO (ethylene oxide) adduct di (meth) acrylate of bisphenol A , PO (propylene oxide) adducts of bisphenol A, di (meth) acrylate, neopentyl glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and triethylene glycol Examples include di (meth) acrylate.

  Examples of the trifunctional or higher functional (meth) acrylate include trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate. Dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, glycerin propoxytri (meth) acrylate, cowprolactone-modified trimethylolpropane tri (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, and Examples include caprolactam-modified dipentaerythritol hexa (meth) acrylate.

  Among these, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and pentaerythritol tri (meth) acrylate are preferable. Glycol di (meth) acrylate and pentaerythritol tri (meth) acrylate are more preferred.

  5-60 mass% is preferable with respect to the whole quantity (100 mass%) of a composition, as for content of a polyfunctional monomer, 10-50 mass% is more preferable, and 15-40 mass% is further more preferable. By setting it as the said preferable range, it exists in the tendency which is excellent with sclerosis | hardenability, storage stability, discharge stability, and the surface gloss of printed matter.

  Moreover, since the toughness of a cured film, heat resistance, and chemical resistance increase, it is also preferable to use a monofunctional (meth) acrylate and a bifunctional (meth) acrylate together, especially phenoxyethyl (meth) acrylate and dipropylene glycol. It is more preferable to use di (meth) acrylate together.

  35-95 mass% is preferable with respect to the whole quantity (100 mass%) of a composition, and, as for content of a polymeric compound, 45-90 mass% is more preferable. When the content of the polymerizable compound is within the above range, the viscosity and odor can be further reduced, and the solubility and reactivity of the photopolymerization initiator and the surface gloss of the printed material should be further improved. Can do.

(Pigment)
The composition contains a pigment as a coloring material. Examples of the pigment include inorganic pigments and organic pigments. Although it does not specifically limit as an inorganic pigment, For example, carbon black (CI pigment black 7), such as furnace black, lamp black, acetylene black, channel black, iron oxide, and titanium oxide are mentioned.

  The organic pigment is not particularly limited, for example, quinacridone pigment, quinacridone quinone pigment, dioxazine pigment, phthalocyanine pigment, anthrapyrimidine pigment, ansanthrone pigment, indanthrone pigment, flavanthrone pigment, Examples include perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments. .

  A pigment is used individually by 1 type or in combination of 2 or more types.

  The content of the pigment is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and 1.0 to 5.0% by mass with respect to the total amount (100% by mass) of the composition. Further preferred. When the pigment content is within the above range, the color developability tends to be superior.

(Pigment dispersant)
The composition contains one or more pigment dispersants in order to improve pigment dispersibility. Although there is no limitation in particular as a dispersing agent except the acid value and amine value which are mentioned later, For example, the dispersing agent currently used for preparing pigment dispersion liquids, such as a polymer dispersing agent, is mentioned. Specific examples include polyoxyalkylene polyalkylene polyamines, vinyl polymers and copolymers, acrylic polymers and copolymers, polyesters, polyamides, polyimides, polyurethanes, amino polymers, silicon-containing polymers, sulfur-containing polymers, fluorine-containing polymers, and epoxies. The thing which has 1 or more types of resin as a main component is mentioned. Commercially available polymer dispersants include Ajinomoto Fine Techno Co., Ajisper series, Solsperz series available from Lubrizol (for example, "Solsperse 36000"), BYK Chemie company's Dispervic series, Enomoto Kasei Co., Ltd. The company's Disparon series is listed.

  In the composition of this embodiment, from the viewpoint of improving the curability of the composition and the dispersion stability of the pigment, at least one of the acid value and the amine value of the pigment dispersant is 10 mgKOH / g or more. Further, from the viewpoint of suppressing polymerization gelation of the composition, the acid value and the amine value of the pigment dispersant are both 50 mgKOH / g or less. A dispersant having a high acid value or amine value effectively improves the curability of the composition because it acts effectively as a catalyst for the polymerization reaction (curing reaction) of a polymerizable compound, particularly a radically polymerizable compound. It is considered that the dispersion stability of the pigment is improved by the influence. On the other hand, a dispersant having a high acid value or amine value effectively acts as a catalyst for a polymerization reaction (curing reaction) of a polymerizable compound, particularly a radical polymerizable compound, thereby causing polymerization gelation (thickening) and composition. It is thought that there is a tendency to reduce the storage stability of the product. At least one of the acid value and the amine value of the pigment dispersant is preferably 15 mg KOH / g or more, 20 mg KOH / g or more, 45 mg KOH / g or less, 40 mg KOH / g or less, 30 mg KOH / g or less in this order. .

  The total amount of the acid value and the amine value of the pigment dispersant is 10 mg KOH / g or more, 15 mg KOH / g or more, 20 mg KOH / g or more, 30 mg KOH / g or more from the viewpoint of improving the curability of the composition and the pigment dispersion stability. In this order, 100 mgKOH / g or less, 90 mgKOH / g or less, 85 mgKOH / g or less, and 82 mgKOH / g or less are preferred in this order.

  The acid value and amine value of the pigment dispersant can be determined by potentiometric titration. Plural kinds of pigment dispersants may be added to the composition. Also in this case, the acid value and amine value of each pigment dispersant need only satisfy the range defined in the present invention. Thus, a pigment dispersant having a measured acid value and amine value within the above ranges may be selected and used for preparing the composition.

(moisture)
The composition of the present embodiment contains moisture, and the moisture content is 0.05% by mass or more and 1.0% by mass or less with respect to the total amount (100% by mass) of the composition. From the viewpoint of further improving the production efficiency of the composition, and from the viewpoint of further improving the storage stability of the composition when the composition contains a polymerizable compound having a vinyl ether group and a (meth) acrylate group. It is preferably 0.5% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.15% or more. This is because moisture has a polymerization inhibiting action of a polymerizable compound having a vinyl ether group and a (meth) acrylate group. In addition, the water content is preferably 1.0% by mass or less and more preferably 0.8% by mass or less from the viewpoint of suppressing a decrease in curability of the composition and from the viewpoint of suppressing precipitation of foreign matters. Preferably, it is further more preferable in it being 0.5 mass% or less. As described above, moisture has an action of inhibiting the polymerization of a polymerizable compound having a vinyl ether group and a (meth) acrylate group, and tends to lower the curability of the composition. In addition, it is considered that moisture causes aggregation of the pigment, and foreign matter is precipitated due to the pigment aggregation.

  As a method for adjusting the amount of water in the composition, for example, each component of the composition, for example, a polymerizable compound, a method for reducing the amount of water in the composition, a method for removing water from the composition, and mixing during preparation of the composition For example, a method for reducing the amount of water. Among these, as a method of reducing the amount of water in the polymerizable compound, more specifically, a method of purifying the polymerizable compound by distillation, a method of permeating the polymerizable compound through a semipermeable membrane that selectively permeates water, And a method of selectively adsorbing water to a water adsorbent that adsorbs water. Among these, a distillation purification method is preferable from the viewpoint of more efficiently and reliably reducing the water content. The amount of moisture is measured according to the method described in the following examples.

  Examples of the water include water from which ionic impurities have been removed as much as possible, such as pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, and distilled water, and ultrapure water. In addition, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, generation of mold and bacteria can be prevented when the ink is stored for a long period of time. This tends to improve the storage stability.

  The composition of this embodiment may contain the arbitrary component which can be used for the conventional ultraviolet curable inkjet ink composition other than said each component. Such optional components include, for example, colorants such as polymerization initiators, pigments and dyes, dispersants, polymerization inhibitors, surfactants, penetrants, humectants, dissolution aids, viscosity modifiers, pH adjusters. Agents, antioxidants, preservatives, antifungal agents, corrosion inhibitors, and chelating agents and other additives and solvents for capturing metal ions that affect dispersion. Each of these is used alone or in combination of two or more.

(Polymerization initiator)
The composition of this embodiment may contain a polymerization initiator. The polymerization initiator is not limited as long as it generates active species such as radicals and cations by the energy of heat or light energy such as ultraviolet rays and initiates polymerization of the polymerizable compound. Are preferred, and radical photopolymerization initiators are preferred. Although it does not specifically limit as a radical photopolymerization initiator, An acyl phosphine oxide type photoinitiator and a thioxanthone type photoinitiator are preferable, and an acylphosphine oxide type photoinitiator is more preferable.

[Acylphosphine oxide photopolymerization initiator]
The composition preferably contains an acylphosphine oxide photopolymerization initiator. Acylphosphine oxide photopolymerization initiators are susceptible to oxygen inhibition, but are suitable for curing with long wavelength LEDs. Further, the acylphosphine oxide photopolymerization initiator can be dissolved more favorably in the composition when the water content in the composition is 1.0% by mass or less with respect to the total amount of the composition.

  Although it does not specifically limit as an acylphosphine oxide type photoinitiator, Specifically, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide And bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide.

  Although it does not specifically limit as a commercial item of an acyl phosphine oxide type photoinitiator, For example, IRGACURE 819 (BSF (trade name, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide), SPEDDCURE TPO ( Lambson brand name, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) and DAROCUR TPO (BASF brand name, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), SPEDDCURE TPO-L ( Lambson brand name, ethyl- (2,4,6-trimethylbenzoyl) phenylphosphine oxide).

  The content of the acylphosphine oxide photopolymerization initiator is preferably 3 to 20% by mass with respect to the total amount (100% by mass) of the composition. When the content is 3.0% by mass or more, the curability tends to be more excellent. From the same viewpoint, the content of the acylphosphine oxide photopolymerization initiator is more preferably 4% by mass or more, and further preferably 7% by mass or more. Further, when the content is 20% by mass or less, the dissolution and storage stability of the solid content is favorably maintained, and the reliability tends to be excellent. From the same viewpoint, the content of the acylphosphine oxide photopolymerization initiator is more preferably 15% by mass or less, and further preferably 13% by mass or less.

[Thioxanthone photopolymerization initiator]
The composition may contain a thioxanthone photopolymerization initiator. When the composition contains a thioxanthone-based photopolymerization initiator, the surface tackiness can be reduced, and the ink surface can be hardened particularly in a thin film susceptible to oxygen inhibition to prevent color mixing and bleeding between dots. In addition, it is preferable to use both an acylphosphine oxide photopolymerization initiator and a thioxanthone photopolymerization initiator because they are more excellent in the curing process using UV-LED and the curability and adhesion of the composition tend to be further improved.

  Although it does not specifically limit as a thioxanthone type photoinitiator, Specifically, it is preferable that 1 or more types chosen from the group which consists of thioxanthone, diethyl thioxanthone, isopropyl thioxanthone, and chloro thioxanthone is included. Although not particularly limited, 2,4-diethylthioxanthone is preferable as diethylthioxanthone, 2-isopropylthioxanthone is preferable as isopropylthioxanthone, and 2-chlorothioxanthone is preferable as chlorothioxanthone. A composition containing such a thioxanthone photopolymerization initiator tends to be more excellent in curability, storage stability, and ejection stability. Among these, a thioxanthone photopolymerization initiator containing diethyl thioxanthone is preferable. By including diethylthioxanthone, there is a tendency that a wide range of ultraviolet light (UV light) can be converted into active species more efficiently.

  Although it does not specifically limit as a commercial item of a thioxanthone type photoinitiator, Specifically, Speedcure DETX (2,4-diethylthioxanthone), Speedcure ITX (2-isopropylthioxanthone), Speedcure CTX (2-chlorothioxanthone) SPEEDCURE CPTX (1-chloro-4-propylthioxanthone (manufactured by Lambson)), KAYACURE DETX (2,4-diethylthioxanthone) (manufactured by Nippon Kayaku Co., Ltd.).

  0.5-5.0 mass% is preferable with respect to the whole quantity (100 mass%) of a composition, and, as for content of a thioxanthone type photoinitiator, 1.0-4.0 mass% is more preferable. When the content is 0.5% by mass or more, the surface tackiness can be further reduced, and the ink surface can be cured and the color mixing and bleeding between dots can be further prevented when the thin film is susceptible to oxygen inhibition. It is in. Further, when the content is 5.0% by mass or less, the ink is less colored by the initiator itself, the hue is less likely to be yellowed, and the adhesiveness of the cured film tends to be excellent.

(Other photopolymerization initiators)
The composition may further contain one or two or more types of photo radical polymerization initiators or photo cationic polymerization initiators other than those described above. Examples of photo radical polymerization initiators other than those described above include, for example, aromatic ketones, aromatic onium salt compounds, organic peroxides, thio compounds (such as thiophenyl group-containing compounds), α-aminoalkylphenone compounds, hexaarylbiimidazoles. Examples include compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.

  Although it does not specifically limit as a commercial item of radical photopolymerization initiators other than the above, For example, IRGACURE 651 (2,2-dimethoxy-1,2-diphenylethane-1-one), IRGACURE 184 (1-hydroxy-cyclohexyl) -Phenyl-ketone), DAROCUR 1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-one), IRGACURE 2959 (1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy- 2-methyl-1-propan-1-one), IRGACURE 127 (2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane -1-one}, IRGACURE 907 (2-methyl-1- (4-methyl Luthiophenyl) -2-morpholinopropan-1-one), IRGACURE 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1), IRGACURE 379 (2- (dimethylamino) ) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone), IRGACURE 784 (bis (η5-2,4-cyclopentadien-1-yl) -Bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium), IRGACURE OXE 01 (1.2-octanedione, 1- [4- (phenylthio)-, 2- ( O-benzoyloxime)]), IRGACURE OXE 02 (ethanone, 1- [9-ethyl-6- (2-methyl) Benzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime)), IRGACURE 754 (oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid, 2- (2-hydroxyethoxy) ethyl ester mixture (above, manufactured by BASF), Speedcure TPO (above, manufactured by Lambson), Lucirin TPO, LR8883, LR8970 (above, manufactured by BASF), and Ubekrill P36 (UCB) For example).

  Although it does not specifically limit as another photocationic polymerization initiator, Specifically, a sulfonium salt and an iodonium salt are mentioned.

  As for content of a photoinitiator, 5-20 mass% is preferable with respect to the whole quantity (100 mass%) of a composition. When the content is within the range, the ultraviolet curing rate can be sufficiently exerted, and the undissolved portion of the photopolymerization initiator and the color derived from the photopolymerization initiator tend to be avoided.

(Polymerization inhibitor)
The composition may contain one or more polymerization inhibitors from the viewpoint of further improving the storage stability. The polymerization inhibitor is not particularly limited, and examples thereof include compounds having a 2,2,6,6-tetramethylpiperidine-N-oxyl skeleton, compounds having a 2,2,6,6-tetramethylpiperidine skeleton, 2 Hindered amine compounds such as compounds having 2,2,6,6-tetramethylpiperidine-N-alkyl skeleton, and compounds having 2,2,6,6-tetramethylpiperidine-N-acyl skeleton; p-methoxyphenol, hydroquinone Monomethyl ether (MEHQ), hydroquinone, cresol, t-butylcatechol, 3,5-di-t-butyl-4-hydroxytoluene, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2, 2′-methylenebis (4-ethyl-6-butylphenol) and 4,4′-thiobis (3-me Le -6-t-butylphenol) and the like.

  The ultraviolet curable composition of this embodiment is accommodated in a container. In other words, the container of this embodiment contains the ultraviolet curable composition of this embodiment. Hereinafter, the case where an ultraviolet curable composition is used as an inkjet ink composition will be described in more detail.

(Container)
One embodiment of the present invention is an ink container containing a non-aqueous ink composition. In this specification, the “container” is a concept including a container and a package, and refers to a container that directly or indirectly contains an ink composition. That is, the container is one in which a container is filled with an ultraviolet curable composition, or at least a container filled with an ultraviolet curable composition is sealed with a package made of members. The ink container is used for storing and transporting the ink composition before using the ink composition in the recording apparatus. When the ink container is used, the ink composition stored in the ink container is supplied to the recording apparatus. To do.

  Examples of the ink container include, but are not limited to, an ink cartridge, a pack, a bottle, a tank, a bottle, and a can. Among these, an ink cartridge, a pack, a bottle, and a tank are preferable, and a pack is more preferable from the viewpoint of being widely used and easily controlling water permeability and oxygen permeability described later to desired values.

  FIG. 1 is an exploded perspective view showing an example of the ink container of the present embodiment. The ink cartridge 3 includes an ink pack 70 that is filled with ink, and a cartridge case 72 that includes a main body case 76 and a lid portion 78 that house and protect the ink pack 70. The ink pack 70 includes an ink supply port 74. The main body case 76 includes a notch portion 80 and a groove portion 86, and the lid portion 78 includes a pressing portion 82 and a flange portion 84. In the ink cartridge 3, the ink pack 70 is accommodated in the main body case 76 and the lid portion 84. At this time, the ink supply port 74 is fitted in the notch portion 80, and then the press portion 82 and the notch portion 80 are inserted. It is fixed by being pinched. Further, the main body case 76 and the lid portion 84 are sealed by fitting the flange portion 84 into the groove portion 86. The ink pack 70 and the cartridge case 72 correspond to the “ink container” in the present embodiment. A configuration that directly stores an ink composition such as the ink pack 70 in the ink container is referred to as a container. An ink container made of only a container, for example, a container in which the container itself is also a container may be used. Further, the container may be provided with a packaging body (not shown). The packaging body only needs to accommodate and seal at least the container, and may be an object that accommodates the entire container, or may be an object that accommodates at least the container and is accommodated inside the container. . The container which consists of a container and a package may be sufficient.

  The use mode of the ink container is not particularly limited. For example, an ink container that is separate from the recording apparatus is mounted on the recording apparatus, and the ink composition is recorded from the ink container in the mounted state. A mode (A) like a cartridge for supplying to a printer, a mode (B) like a bottle for supplying an ink composition to an ink tank or the like of a recording device from an ink container separate from the recording device, and an ink And a mode (C) in which the container is previously provided as a part of the recording apparatus. In the case of the mode (A) and the mode (C), the ink composition is supplied to the head of the recording apparatus from the mounted container or the installed ink container through a connecting portion such as an ink tube. Thus, recording can be performed. In the aspect (B), after the ink composition is transferred from the ink container to the ink tank or the like of the recording apparatus, the ink composition is supplied from the ink tank to the head of the recording apparatus through a connection portion such as an ink tube. Thus, recording can be performed.

  The material of the member constituting the container such as the ink pack 70 or the package is not particularly limited. For example, polyethylene terephthalate (PET), polypropylene, polyethylene, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer (EVOH) ), A resin such as polystyrene; or an inorganic material such as glass. In addition, the said structural material may be mix | blended and used by a suitable ratio, or may be used in multiple types.

  As said structural member, a film is preferable at the point of a softness | flexibility or weight reduction. The material of the member is not particularly limited as a durable film material. For example, a plastic film such as polyethylene terephthalate (PET), polyethylene, polypropylene, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, polystyrene, etc. Is mentioned. Among these, high density, low density, or linear low density polyethylene, polypropylene, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, and polystyrene are preferable. The film material may be a laminated film or a stretched film.

The oxygen permeability of the ink container or the packaging member that contains and seals the container is 0.01 cc to 5.0 cc · 20 μm / (m ² · day · atm) at 23 ° C. and 65% humidity. . An oxygen permeability of 0.01 cc · 20 μm / (m ² · day · atm) or more is preferable from the viewpoint of the degree of freedom in designing the member, and the polymerization gelation of the composition during storage can be suppressed. There is a tendency. When the oxygen permeability is 5.0 cc · 20 μm / (m ² · day · atm) or less, the amount of dissolved oxygen in the composition during storage tends to hardly change, and the ejection stability of the composition Tend to improve. The oxygen permeability can be measured by a method defined in JIS K 7126 (ISO 15105).

  In order to improve the oxygen permeability, the ink container may have a gas barrier layer. The gas barrier layer is not particularly limited, and examples thereof include a metal layer such as an aluminum layer, an organic layer such as an ethylene vinyl alcohol copolymer layer, and a polyvinyl alcohol layer.

  The total thickness of the members is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 30 μm or more, still more preferably 40 μm or more, and even more preferably 70 μm or more. When the total thickness is 10 μm or more, the water content and dissolved oxygen content of the ink composition to be stored are hardly changed, and the strength of the ink container tends to be obtained. The total thickness is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less. When the total thickness is 200 μm or less, visibility and flexibility tend to be further improved.

  The volume of the ink composition that can be accommodated in the ink container is preferably 100 to 3,000 mL, more preferably 100 to 2,000 mL, still more preferably 100 to 1,000 mL, and particularly preferably 100. It is -800 mL, More preferably, it is 200-800 mL. Since the capacity of the ink container is within the above range, the ink composition can be used up and stored while the amount of dissolved oxygen in the ink container hardly changes after the start of use of the ink container. There are advantageous effects such as that the dissolved oxygen amount of the ink composition in the inside is hardly changed.

The moisture permeability of the member is preferably 20 g / m ² · 24 hours or less, more preferably 10 g / m ² · 24 hours or less, and further preferably 5.0 g / m ² · 24 hours or less. . When the moisture permeability is 20 g / m ² · 24 hours or less, the amount of moisture in the contained composition tends to hardly increase, the change in the pigment particle size is less likely to occur, and the generation of foreign matter is suppressed. There is a tendency that the long-term storage stability of the composition is further improved. The water permeability of the ink container is not limited, but is preferably 0.10 g / m ² · 24 hours or more, more preferably 0.20 g / m ² from the viewpoint of design freedom. It is 24 hours or more, more preferably 1.0 g / m ² · 24 hours or more, and still more preferably 2.0 g / m ² · 24 hours or more. The water permeability can be measured by gas chromatography.

  Thus, according to the present embodiment, it is possible to provide a container that contains an ultraviolet curable composition that is excellent in curability and that can suppress the precipitation of foreign substances and that has high production efficiency.

The ink jet apparatus of the present embodiment is an apparatus including an ink jet head that uses the above-described ink jet composition and container and discharges the composition by an ink jet method. The ink jet method of the present embodiment includes the composition from the ink jet head. A discharge process for discharging the object is provided. You may provide the hardening process which discharges with respect to a to-be-discharged body, and hardens the composition adhering to to-be-discharged body by irradiation of an ultraviolet-ray, and the irradiation apparatus which performs this hardening process. In the irradiation step, it is preferable to use a metal halide lamp, a mercury lamp, an ultraviolet light emitting diode, or the like as the ultraviolet light source, and an ultraviolet light emitting diode is more preferable in terms of miniaturization and power saving. As the ultraviolet light emitting diode, one having an emission peak wavelength preferably in the range of 360 to 420 nm is preferable in that it is easily available. Irradiation energy of the curing step, to sufficiently cure the composition, in terms of shorter time of curing step, preferably ^{100~1000mJ / cm 2, 800mJ / cm} 2 or ^{less, mJ / cm 2, 600mJ /} cm 2 or less of More preferable in the order of 200 mJ / cm ² or more and 300 mJ / cm ² or more. Other configurations of the method and apparatus are not particularly limited. For example, as a configuration other than that, a conventionally known configuration may be provided. According to the ink jet apparatus and the ink jet method of the present embodiment, the ink jet composition is excellent not only in curability but also in the discharge stability because it is possible to suppress the precipitation of foreign matters in the composition. In particular, when the composition contains a polymerizable compound having a vinyl ether group and a (meth) acrylate group, the composition is excellent in storage stability even though the composition is cured by irradiation with ultraviolet rays. It will be a thing. Further, when the composition contains a polymerizable compound having a vinyl ether group, the viscosity of the composition can be lowered, and thus discharge stability can be further enhanced from such a viewpoint.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

[Material for UV-curable composition]
The main materials for ultraviolet curable compositions used in the following examples and comparative examples are as follows.
[Color material]
P. I. Pigment Blue 15: 4
(Pigment dispersant)
BYK9076, BYKJET9150, BYK2155, BYK2008, DISPERBYK102, ANTI-TERRA U100 (BIC Chemie Japan product name) Azisper PB881, Ajisper PN411 (Ajinomoto Finetechno product name)
[Polymerizable compound]
VEEA (2- (2-vinyloxyethoxy) ethyl acrylate, Nippon Shokubai Co., Ltd., functional group number 1)
PEA (phenoxyethyl acrylate, Osaka Organic Chemical Co., Ltd., functional group number 1)
DPGDA (dipropylene glycol diacrylate, manufactured by Sartomer, 2 functional groups)
SR444 (pentaerythritol triacrylate, Nippon Kayaku Co., Ltd., functional group number 3)
(Polymerization inhibitor)
MEHQ (hydroquinone monomethyl ether, manufactured by Tokyo Chemical Industry Co., Ltd.)
(Polymerization initiator)
IRGACURE TPO (trade name, manufactured by BASF, solid content: 100% by mass)
IRGACURE 369 (BASF brand name, solid content 100% by mass)
KAYACURE DETX (trade name, manufactured by Nippon Kayaku Co., Ltd., solid content: 100% by mass)

(Examples 1-25, Comparative Examples 1-11)
[Preparation of UV-curable composition]
Each material was prepared as a composition with the composition (mass%) shown in the following Tables 1-2. First, the PEA, pigment, and pigment dispersant of the materials are mixed and sufficiently stirred to disperse the pigment, then the remaining materials are mixed and sufficiently stirred to prepare each composition (ultraviolet curable composition). Product). Each polymerizable compound was used after being purified by distillation once or several times for each polymerizable compound used in each Example and Comparative Example, or by adding ion-exchanged water to the composition. The amount was adjusted to the value in the table. Next, a laminated film in which an aluminum vapor deposition film is laminated on a high-density polyethylene film (thickness 100 μm) is stacked with the aluminum vapor deposition film (thickness 10 μm) on the outside, and the surroundings are thermally welded to create a pack as a container. Each composition prepared above was filled in a container with a volume of 700 mL, the container was sealed so that air did not enter, and the container was stored in a protective case to obtain a composition container. However, Examples 20-25 differed from the other examples in the thickness of the aluminum vapor deposition film of the film.

(Measurement of water content)
Using a moisture meter (product name “Automatic Heat Vaporization Moisture Measurement System AQS-22010” manufactured by Hiranuma Sangyo Co., Ltd.), the moisture content in the ultraviolet curable composition was measured by the Karl Fischer coulometric method. The results are shown in Tables 1-2 (mass basis).

(Measurement of acid value and amine value)
Regarding the acid value and amine value of the pigment dispersant, the acid value was measured by the method described in JIS K 0070, and the amine value was measured by the method described in JIS K 7237. The measurement was performed using AT610 manufactured by Kyoto Electronics Manufacturing Co., Ltd.

(Oxygen permeability)
The oxygen permeability of the film which comprises the container used for the composition container produced for every example was measured. The oxygen permeability was measured by a JIS K 7126 plastic film and sheet gas permeability test method (gas chromatograph method) at 23 ° C. and a humidity of 65%. One (low pressure side) separated by the test piece is kept in a vacuum, the test gas is introduced to the other (high pressure side), and the amount of gas that has passed through the test piece at 23 ° C. and 65% humidity and permeated to the low pressure side is gas chromatograph. The gas permeability was calculated by measuring by the tograph method.

(Evaluation of curability)
Using a bar coater, the ultraviolet curable composition was applied onto a PET film (PET50A PL Thin [trade name], manufactured by Lintec Corporation) to prepare a coating film having a thickness of 14 μm. Then, the said coating film was hardened by irradiating the ultraviolet-ray whose irradiation intensity | strength is 1100 mW / cm < ² > and whose wavelength is 395 nm. The cured coating film (cured film) was rubbed 10 times with a cotton swab at a load of 100 g, and the curing energy (irradiation energy) at the time when the scratch was not found was determined.
The irradiation energy [mJ / cm ² ] was determined from the product of the irradiation intensity [mW / cm ² ] on the irradiated surface irradiated from the light source and the irradiation duration [s]. The irradiation intensity was measured using an ultraviolet intensity meter UM-10 and a light receiving unit UM-400 (both manufactured by Konica Minolta Sensing, Inc.). Based on the result of irradiation intensity, the following evaluation criteria were used. The results are shown in Tables 1-2.
◎: 250mJ / cm ² or less ○: 250mJ / cm ² to more than 350mJ / cm ² or less △: 350mJ / cm ² to more than 400mJ / cm ² or less ×: 400mJ / cm ² more than

(Evaluation of pigment dispersion stability (inhibition of foreign matter precipitation))
After discharging for 60 minutes, the filter of the head was taken out and the residue accumulated on the filter was visually observed and evaluated according to the following evaluation criteria. A filter having a nominal mesh size of 2800 was used. The results are shown in Tables 1-2. The residue that was confirmed to be generated contained at least a pigment. It is an evaluation relating to the generation of foreign matters due to at least the pigment.
A: No residue.
○: There are very few fine residues.
(Triangle | delta): In addition to a fine residue, there is also a little large residue.
X: There is considerable large residue.
XX: The filter is almost filled with residue.

(Evaluation of polymerization gelation (thickening))
After the ultraviolet curable composition was contained in a glass bottle, the glass bottle was sealed and stored at 60 ° C. for 2 weeks. The viscosity at 20 ° C. of the ultraviolet curable composition before and after storage was measured with a viscometer manufactured by phisica, and the viscosity of the ultraviolet curable composition after storage relative to the viscosity of the ultraviolet curable composition before storage. Was calculated by what percentage, i.e., what percentage thickened. This is an evaluation relating to storage stability when the composition is stored for a long period of time. Based on the result, the following evaluation criteria were used. The results are shown in Tables 1-3.
A: Thickening is less than 3% B: Thickening is 3% or more and less than 6% B: Thickening is 6% or more and less than 9% X: Thickening is 9% or more and less than 12% XX: Thickening is 12% or more

(Evaluation of ejection stability)
A head having 360 nozzles is fixed to the top, and a PET film (product number “PET50 K2411 PAT1E”, manufactured by Lintec Corporation) is transported at 15 m / min below the nozzles of the head, and 180 kHz from the nozzles to the PET film is 10 kHz. The UV curable composition was discharged and continuous printing was performed. Simultaneously with printing, an image was formed by irradiating the ink composition attached to the PET film with an LED having an emission wavelength peak of 395 nm. Every 5 minutes from the start of discharge, whether or not the ultraviolet curable composition was discharged from all nozzles was visually confirmed and evaluated according to the following evaluation criteria. The results are shown in Tables 1-3.
A: No nozzle missing for 60 minutes or more.
○: Nozzle missing in 30 minutes or more and less than 60 minutes.
Δ: Nozzle missing in 15 minutes or more and less than 30 minutes.
X: Nozzle missing in less than 15 minutes.

(Evaluation of dehydration process efficiency (manufacturing efficiency))
Each polymerizable compound obtained by a conventional method was purified by distillation once using a rotary evaporator. Using VEEA after purification by distillation, UV curable compositions having the compositions shown in Tables 1 and 2 were prepared, and the water content was measured. The above-mentioned distillation purification, preparation of the ultraviolet curable composition and measurement of the moisture content were repeated until the moisture content reached the values shown in Tables 1 and 2. The following evaluation was made based on the number of distillation purifications. The smaller the number of distillation purifications, the higher the dehydration process efficiency (production efficiency). The results are shown in Tables 1-3.
○: 2 times or less.
Δ: 3 to 4 times.
X: 5 times or more.

  From the results of the examples, the water content is 0.05% by mass or more and 1.0% by mass or less with respect to the total amount of the ultraviolet curable inkjet composition, and the acid value and amine value of the pigment dispersant are both When it is 50 mgKOH / g or less and at least one is 10 mgKOH / g or more, it is excellent in curability and pigment dispersion stability (inhibition of foreign matter precipitation), suppression of polymerization gelation, excellent discharge stability, and improved dehydration process efficiency. I understand that I can do it.

  From comparison between Examples 1, 5, and 12 and Comparative Example 8, when the water content is 1.0% by mass or less, the pigment dispersion stability (foreign matter suppression) is excellent, and as a result, the discharge stability is improved. It turns out that it is excellent and it is excellent also in sclerosis | hardenability. From the comparison between Example 1 and Comparative Example 1, when the water content is 0.05% by mass or more, polymerization gelation (thickening) can be suppressed, and as a result, the discharge stability is excellent, and the dehydration step Excellent efficiency.

  From the comparison between Examples 1, 2, 7 to 9, 15 to 17 and Comparative Example 5, when the water content is 0.05% by mass or more and 1.0% by mass or less, the acid value and amine value of the pigment dispersant are It was found that when any of the above was 10 mg KOH / g or more, the pigment dispersion stability (foreign matter precipitation suppression) was excellent, and as a result, the discharge stability was excellent and the curability was also excellent.

  Further, when the water content is 0.05% by mass or more and 1.0% by mass or less by comparison between Examples 1, 2, 7 to 9, 15 to 17 and Comparative Examples 6 and 7, the acid of the pigment dispersant It was found that when both the valence and the amine value are 50 mgKOH / g or less, polymerization gelation (thickening) can be suppressed, and as a result, the discharge stability tends to be excellent.

  Moreover, from Comparative Examples 1-4, when the moisture content was less than 0.05 mass%, it turned out that the viscosity increase of a composition is large. When the amount of water is small, it is presumed that the polymerization gelation of the composition cannot be suppressed and the thickening is large. In addition, the composition in which the polymerization gelation (thickening) such as Comparative Examples 1 to 4 is inferior tends to be inferior in discharge stability, and a fine gelation product due to the polymerization gelation is generated in the composition. Presumed that the discharge stability was inferior.

  Furthermore, from Comparative Examples 8 to 11, when the water content exceeded 1.0 mass%, generation of a residue was observed, and pigment dispersion stability (foreign matter precipitation suppression) was lowered. It is presumed that there was a tendency for the pigments to easily become foreign substances due to moisture. Further, in this case, it was found that curability is also lowered. In particular, in Comparative Example 9, in addition to the fact that the pigment dispersant was insufficiently dispersed and the generation of residues was observed because either the acid value or the amine value of the pigment dispersant was not 10 mg KOH / g or more. Further, it is presumed that the generation of a residue was observed due to inferior suppression of foreign matter precipitation even when the water content exceeded 1.0 mass%.

  40 ... ink cartridge, 70 ... ink pack, 72 ... cartridge case, 74 ... ink supply port, 76 ... main body case, 78 ... lid part, 80 ... notch part, 82 ... pressing part, 84 ... collar part, 86 ... groove part .

Claims (11)

A radical polymerization type ultraviolet curable inkjet composition containing a pigment, a pigment dispersant, a radical polymerizable compound, and a photopolymerization initiator, and contained in a container,
The water content is 0.05% by mass or more and 0.2% by mass or less with respect to the total amount of the ultraviolet curable inkjet composition, the amine value of the pigment dispersant is 50 mgKOH / g or less, and the acid value is 50 mgKOH / g. The acid value and amine value of the pigment dispersant are both 20 mgKOH / g or more,
As the polymerizable compound, containing a polymerizable compound having a vinyl ether group and a (meth) acrylate group,
UV curable ink jet composition. The ultraviolet curable inkjet composition according to claim 1, wherein the pigment dispersant has an acid value and an amine value of 45 mgKOH / g or less, respectively. The ultraviolet curable inkjet composition according to claim 1 or 2 , wherein the total amount of the acid value and the amine value of the pigment dispersant is 30 mgKOH / g or more and 90 mgKOH / g or less. The ultraviolet curable inkjet composition according to claim 1 or 2, wherein the total amount of the acid value and the amine value of the pigment dispersant is from 82 mgKOH / g to 100 mgKOH / g. The ultraviolet curable inkjet composition according to any one of claims 1 to 4, comprising an acylphosphine oxide compound as the photopolymerization initiator. The polymerizable compound having the vinyl ether group and the (meth) acrylate group is contained in an amount of 10 to 70% by mass with respect to the total amount of the ultraviolet curable composition, according to any one of claims 1 to 5 . UV curable ink jet composition. As a polymerizable compound having the vinyl ether group and the (meth) acrylate group, the following general formula (1):
_{^{CH 2 = CR 1 -COOR 2 -O}} -CH = CH-R 3 ··· (1)
Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a divalent organic residue having 2 to 20 carbon atoms, and R ³ is a hydrogen atom or a monovalent organic residue having 1 to 11 carbon atoms. The ultraviolet curable inkjet composition of any one of Claims 1-6 containing the vinyl ether group containing (meth) acrylic acid ester represented by this.   The ultraviolet curable inkjet composition according to claim 7, wherein the vinyl ether group-containing (meth) acrylic acid ester is 2- (vinyloxyethoxy) ethyl acrylate.   The ultraviolet curable inkjet composition of any one of Claims 1-8 whose content of the said radically polymerizable compound is 45 mass% or more with respect to the whole quantity of an ultraviolet curable inkjet composition.   The container which accommodated the ultraviolet curable inkjet composition of any one of Claims 1-9. The container includes the ultraviolet curable inkjet composition in a container made of a member having an oxygen permeability of 0.01 cc to 5.0 cc · 20 μm / (m ² · day · atm) at 23 ° C. and 65% humidity. Or a container filled with at least the ultraviolet ray curable ink jet composition is 0.01 cc to 5.0 cc · 20 μm / (m ² · m at 23 ° C. and 65% humidity. 11. The container according to claim 10, wherein the container is sealed with a package made of a member that is day · atm).

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