JP2008239958A - Polysilane compound and synthesis method thereof, ultraviolet curable ink composition using the polysilane compound, inkjet recording method using the ultraviolet curable ink composition, and ink container containing the ultraviolet curable ink composition Inkjet recording device - Google Patents

Abstract

【選択図】なしProvided are a novel polysilane compound and a method for synthesizing the same, and an ultraviolet curable ink composition using the above compound, having a high curing (polymerization) rate and excellent storage stability. An ink jet recording method using the ink, a container containing the ink, and a recording apparatus are provided.
An ultraviolet curable ink composition having a structure represented by the following formula 1.

[Selection figure] None

Description

The present invention relates to a polysilane compound and a synthesis method thereof, and an ultraviolet curable ink composition using the polysilane compound, and more specifically, a novel polysilane compound and a synthesis method thereof, and an ink composition using the polysilane compound. The present invention relates to an ultraviolet curable ink composition which is cured by actinic rays such as ultraviolet rays, has a high curing (polymerization) rate, is excellent in storage stability, and has little increase in viscosity even when stored at high temperatures.
The present invention also relates to an ink jet recording method using the ultraviolet curable ink composition, an ink container and an ink jet recording apparatus in which the ultraviolet curable ink composition is accommodated.

  The ink jet recording method is a printing method in which printing is performed by causing a droplet of an ink composition to fly and adhere to a recording medium such as paper. This ink jet recording method is characterized in that a high-resolution and high-quality image can be printed at high speed. The ink composition used in the ink jet recording method generally contains an aqueous solvent as a main component and a coloring material component and a wetting agent such as glycerin for the purpose of preventing clogging.

  Also, recording media such as paper and fabrics that are difficult to penetrate water-based ink compositions, or materials such as metals, plastics, etc. that do not penetrate, such as plates, films, etc., made from resins such as phenol, melamine, vinyl chloride, acrylic, polycarbonate, etc. When printing on the ink composition, the ink composition is required to contain a component capable of stably fixing the coloring material to the recording medium. In particular, when printing on a printed wiring board or the like, the ink composition is required to have quick drying properties and chemical resistance.

  In response to such a demand, conventionally, an ink composition including a component that is polymerized by ultraviolet irradiation has been proposed (see, for example, Patent Document 1). In addition, an ultraviolet curable ink composition containing a coloring material, an ultraviolet curing agent, a photopolymerization initiator, and the like has been proposed (see, for example, Patent Document 2). According to these ink compositions and ink jet recording methods, it is said that the ink composition can be prevented from bleeding into the recording medium and the image quality can be improved.

  In the ink jet recording method using the ink composition containing a component that becomes polymerized by irradiation with ultraviolet rays as described above, the ink composition is attached to a recording medium and then irradiated with ultraviolet rays. . Then, the photopolymerization initiator in the ink composition generates radicals and the like, whereby the oligomer and the monomer start to be polymerized and harden, so that the color material in the ink composition is fixed on the recording medium. This fixation is considered to realize printing with high film strength, solvent resistance, color density, and less bleeding and unevenness.

In addition, regarding conventional ultraviolet curable ink compositions, those having high curability, such as generally high curing speed, have low storage stability, and increase in viscosity over time or gel when stored at high temperatures. In addition, not only ink jet recording but also other recording methods cannot be used. On the other hand, when the storage stability is increased, the curability is also lowered, and strong ultraviolet irradiation is required, which increases the size of the apparatus and increases the power consumption, which is not preferable.
This is presumably because the photopolymerization initiator in the ink composition not only generates radicals and the like when irradiated with ultraviolet rays, but also generates radicals and the like by thermal energy.

JP-A-3-216379 US Pat. No. 5,562,001

As described above, various attempts have been made to meet the demands of both an improvement in polymerization rate and an improvement in storage stability, but the development of an ink composition that satisfies both “high polymerization rate and high storage stability” has been made. Not achieved.
Accordingly, the present invention has been made to solve the above-described problems, and provides a novel polysilane compound and a method for synthesizing the same, as well as a high curing (polymerization) rate and storage stability using the polysilane compound. An object of the present invention is to provide an ultraviolet curable ink composition which is excellent in properties and has little increase in viscosity even when stored at high temperatures.
Another object of the present invention is to provide an ink jet recording method using the ultraviolet curable ink composition, and an ink container and an ink jet recording apparatus each containing the ultraviolet curable ink composition.

As a result of intensive studies, the present inventor has found that the above object can be achieved by using a novel polysilane having a special structure as a photopolymerization initiator, and has accomplished the present invention.
That is, the present invention is as follows.
(1) A polysilane compound having a structure represented by the following formula 1.

[In Formula 1, m and n represent a molar ratio, and m + n = 1 is a positive number. p represents an integer of 2 or more and 10 or less. q represents an integer of 0 or more and 5 or less.
R1 is, _{-CH 2} CH 2 - or _-CH 2 CH (CH ₃₎ - represents a.
R2 and R3 each independently represents an alkyl group having 1 to 12 carbon atoms, a phenyl group, or a benzyl group. The phenyl group and benzyl group may be further substituted with a substituent X1.
R4 represents a phenyl group. The phenyl group may be further substituted with a substituent X1.
R5 represents an alkyl group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, a halogen group, a cyano group, an acyl group, an acyloxy group, a benzoyl group, and a nitro group.
The substituent X1 represents an alkyl group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, a halogen group, a cyano group, an acyl group, an acyloxy group, a benzoyl group, and a nitro group. ]
(2) The polysilane compound according to (1) above, wherein the maximum absorption coefficient at 290 nm to 410 nm is 1000 or more.
(3) The polysilane compound as described in (1) or (2) above, having an average molecular weight of 5000 or more.
(4) The polysilane compound according to any one of (1) to (3) above, which is soluble in a hydrophilic acrylate.
(5) The method for synthesizing a polysilane compound according to any one of the above (1) to (4), wherein a monomer is synthesized using bromide as a starting material and then copolymerized using the monomer.
(6) An ultraviolet curable ink composition containing the polysilane compound according to any one of (1) to (4) above.
(7) An ink jet recording method using the ultraviolet curable ink composition described in (6) above.
(8) An ink container comprising the ultraviolet curable ink composition described in (6) above.
(9) An ink jet recording apparatus comprising the ultraviolet curable ink composition described in (6) above.

  The mechanism of action of the present invention is not clear, but by containing the novel polysilane compound in the ultraviolet curable ink composition, the action as a photopolymerization initiator can increase the curing (polymerization) rate, Since it is a polysilane compound having high thermal stability, it is presumed that storage stability can be improved because it is not decomposed by thermal energy and does not generate radicals.

  By using the novel polysilane compound of the present invention, an ultraviolet curable type having a high curing (polymerization) rate and excellent storage stability can be provided.

  Hereinafter, the polysilane compound having a structure represented by the following formula 1 of the present invention will be described in detail.

[In Formula 1, m and n represent a molar ratio, and m + n = 1 is a positive number. p represents an integer of 2 or more and 10 or less. q represents an integer of 0 or more and 5 or less.
R1 is, _{-CH 2} CH 2 - or _-CH 2 CH (CH ₃₎ - represents a.
R2 and R3 each independently represents an alkyl group having 1 to 12 carbon atoms, a phenyl group, or a benzyl group. The phenyl group and benzyl group may be further substituted with a substituent X1.
R4 represents a phenyl group. The phenyl group may be further substituted with a substituent X1.
R5 represents an alkyl group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, a halogen group, a cyano group, an acyl group, an acyloxy group, a benzoyl group, and a nitro group.
The substituent X1 represents an alkyl group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, a halogen group, a cyano group, an acyl group, an acyloxy group, a benzoyl group, and a nitro group. ]

  The alkyl group represented by R2, R3, R5 and X1 is preferably a linear or branched alkyl group having 1 to 12 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms. Alkyl group, more preferably methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, Nonyl group and decyl group. These alkyl groups may further have a substituent.

  Examples of the halogen atom in the halogen group represented by R5 and X1 include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Examples of the alkoxyl group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the acyl group include a formyl group and an acetyl group. Examples of the acyloxy group include an acetoxy group.

From the viewpoint of photoreactivity, the polysilane compound according to the present invention preferably has a maximum absorption coefficient of 290 nm to 410 nm of 1000 or more, more preferably 5000 or more. From the viewpoint of photoreactivity, the average molecular weight is preferably 5,000 or more, more preferably 10,000 or more, and particularly preferably 200,000 or more.
Further, the polysilane compound is preferably 0.01% by mass or more in a hydrophilic acrylate preferable as an ink film component, and is soluble to the extent that it does not precipitate at a normal ink composition concentration, and has a molecular weight of R1 to R5. It can be made soluble by appropriate selection of the substituents represented.

  The polysilane compound can be synthesized by the following process using bromide as a starting material. By selecting bromide as a starting material, there is an advantage of obtaining a simple and low-cost polysilane compound. The case where the repeating unit is the following (A) and (B) will be described as an example.

  Reaction 3 above is described in R.I. West. et al. , J .; This is a copy of the reaction described in Radiation Curing, 13, 35 (1986). The polysilane copolymer obtained by the above reaction is a random copolymer, but by copolymerizing an oligomer composed of the repeating unit A and an oligomer composed of the repeating unit B, a polysilane block copolymer such as “-AAAABBBBAAABBB-” is used. A coalescence can also be synthesized.

  The repeating unit (A) in the polysilane copolymer of the present invention is preferably contained in an amount of 10 to 90 mol% (that is, m = 0.1 to 0.9), more preferably 40 to 60 mol%. (That is, m = 0.4 to 0.6).

  The polysilane compound of the present invention can be used as a photopolymerization initiator in ultraviolet curable adhesives, ultraviolet curable paints, ultraviolet curable coating agents, ultraviolet curable hard coating agents, ultraviolet curable ink compositions, and the like. In particular, by using the polysilane compound of the present invention in an ultraviolet curable ink composition, an ink composition having a high curing rate, excellent storage stability, and little increase in viscosity even when stored at high temperatures can be obtained.

Hereinafter, the ultraviolet curable ink composition of the present invention (hereinafter, also simply referred to as “ink composition”) will be described in detail.
The above polysilane copolymer may be used alone as a photopolymerization initiator or may be used in combination with other initiators, but has a high curing (polymerization) rate, storage stability, and storage at high temperatures. In order to achieve the object of the present invention in which the increase in viscosity is small, the single use is preferable. Representative photopolymerization initiators that can be used in combination include benzoin methyl ether, benzoin ethyl ether, isopropyl benzoin ether, isobutyl benzoin ether, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl). Examples include oxime, benzyl, diethoxyacetophenone, benzophenone, chlorothioxanthone, 2-chlorothioxanthone, isopropylthioxanthone, 2-methylthioxanthone, polyphenyl chloride, hexachlorobenzene and the like.

  Also, Vicure 10, 30 (manufactured by Stauffer Chemical), Irgacure 184, 651, 2959, 907, 369, 1700, 1800, 1850, 819 (manufactured by Ciba Specialty Chemicals), Darocur 1173 (manufactured by EM Chemical), QuantureCTX, ITX Photopolymerization initiators available under the trade names of Chemical) and Lucirin TPO (BASF) may be used in combination.

  The total content of the photopolymerization initiator is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass, based on the total amount of the ink composition.

A main component other than the photopolymerization initiator contained in the ink composition of the present invention is a polymerizable compound. The polymerizable compound is not particularly limited as long as it is a compound that causes a polymerization reaction by being imparted with some energy and cures, and can be used regardless of the type of monomer, oligomer, or polymer. Various known polymerizable monomers known as photo-cationic polymerizable monomers and photoradical polymerizable monomers that cause a polymerization reaction by the generated starting species are preferable.
One or more polymerizable compounds can be used in combination for the purpose of adjusting the reaction rate, ink physical properties, cured film physical properties, and the like.
As the monomer, any of a monofunctional monomer, a bifunctional monomer, and a trifunctional or higher polyfunctional monomer described in JP-A-2006-28392 can be used, and any of these monomers is used for primary skin irritation (PII, The Primary Irritation Index is preferably 2 or less.
Further, from the viewpoint of reducing the viscosity of the ink composition, it is preferable that the amount of the bifunctional monomer and polyfunctional monomer used is as small as possible.

  Examples of monofunctional monomers, bifunctional monomers and polyfunctional monomers having a PII value of 2 or less that can be used in the ink composition of the present invention are shown in Table 1 below.

  In addition, the viscosity in the said table | surface is a measured value in 25 degreeC.

Further, the ink composition of the present invention may contain an oligomer in addition to the aforementioned monomer as the polymerizable compound.
The oligomer that can be used in the ink composition of the present invention is a molecule having a medium relative molecular mass, generally a small number of units substantially or conceptually obtained from a molecule having a small relative molecular mass. Means one having a structure constituted by repetition of about 2 to 20 times. The oligomer used in the present invention is also called a photopolymerizable prepolymer, base lysine or acrylic oligomer.

Since the oligomer has 1 to several acryloyl groups as functional groups, it has a property of causing a polymerization reaction with a monomer or the like by ultraviolet irradiation or the like to crosslink and polymerize.
Examples of the oligomer used in the present invention include polyester acrylate, polyurethane acrylate, epoxy acrylate, polyether acrylate, oligo acrylate, alkyd acrylate, polyol acrylate and the like depending on the molecular structure constituting the skeleton, preferably polyester acrylate, polyurethane Acrylate.
The oligomer used in the present invention has a molecular weight in the range of about 500 to 20,000, preferably in the range of about 5,000 to 10,000.

The ink composition of the present invention may further contain a dendritic polymer as the polymerizable compound. Dendritic polymers can be broadly classified into six structures as shown below ("dendritic polymers-a world of high functionality with multi-branched structures-" supervised by Keigo Aoi / Masaaki Enomoto, NT Co., Ltd.・ See S).
I Dendrimer
II Linear dendritic polymer
III Dendrigraft polymer
IV Hyperbranched polymer
V star hyperbranched polymer
VI Hyper Graft Polymer

  Among these, “I to III” has a degree of branching (DB) of 1 and has a defect-free structure, whereas “IV to VI” may include a defect. It has a random branch structure. In particular, dendrimers can be arranged with high density and concentration of reactive functional groups on the outermost surface compared to generally used linear polymers. Expectation is high. Further, although hyperbranched polymers, dendrigraft polymers, and hypergraft polymers are not as large as dendrimers, it is possible to introduce many reactive functional groups on the outermost surface and are excellent in curability.

  Unlike conventional linear polymers and branched polymers, these dendritic polymers repeat highly branched structures in three dimensions and are highly branched. Therefore, it is possible to keep the viscosity low compared to a linear polymer having the same molecular weight.

  Examples of the method of synthesizing the dendrimer that can be used in the present invention include a divergent method for synthesizing from the center to the outside and a convergent method for synthesizing from the outside to the center.

  The dendrimer, hyperbranched polymer, dendrigraft polymer and hypergraft polymer that can be used in the present invention are preferably solids at room temperature and have a number average molecular weight in the range of 1,000 to 100,000, particularly in the range of 2000 to 50,000. Are preferably used. When it is not solid at room temperature, the maintainability of the formed image is deteriorated. In addition, when the molecular weight is lower than the above range, the fixed image becomes fragile, and when the molecular weight is higher than the above range, the viscosity of the ink becomes too high even if the addition amount is lowered, in terms of flight characteristics. It is no longer practical.

  The dendrimers, hyperbranched polymers, dendrigraft polymers and hypergraft polymers that can be used in the present invention are dendrimers, hyperbranched polymers, dendrigraft polymers and hypergraft polymers having a radically polymerizable functional group on the outermost surface. Preferably there is. By adopting a structure capable of radical polymerization on the outermost surface, the polymerization reaction proceeds rapidly.

  Examples of the polymer having a dendrimer structure include amidoamine dendrimers (US Pat. Nos. 4,507,466, 4,558,120, 4,568,737, 4,587,329, and 4). 631,337, 4,694,064), phenyl ether dendrimers (US Pat. No. 5,041,516, Journal of American Chemistry 112 (1990, pages 7638-7647)) Etc. As for the amidoamine dendrimer, a dendrimer having a terminal amino group and a carboxylic acid methyl ester group is commercially available as “Starburst ™ (PAMAM)” from Aldrich. In addition, the terminal amino group of the amidoamine-based dendrimer can be reacted with various acrylic acid derivatives and methacrylic acid derivatives to synthesize amidoamine-based dendrimers having corresponding terminals, and then used.

  Examples of acrylic acid derivatives and methacrylic acid derivatives that can be used include acrylic acid such as methyl, ethyl, n-butyl, t-butyl, cyclohexyl, palmityl, and stearyl, or alkyl esters of methacrylic acid, acrylic acid such as acrylic acid amide, and isopropylamide. Alternatively, methacrylic acid alkylamides may be mentioned, but not limited thereto.

Various examples of the phenyl ether dendrimer are described in, for example, the above Journal of American Chemistry Vol. 112 (1990, pages 7638-7647). For example, 3,5-dihydroxybenzyl alcohol is used, A second-generation benzyl alcohol was synthesized by reacting with 5-diphenoxybenzyl bromide, the OH group was converted to Br using CBr ₄ and triphenylphosphine, and then reacted with 3,5-dihydroxybenzyl alcohol in the same manner. The next generation benzyl alcohol is synthesized, and the following reaction is repeated to synthesize the desired dendrimer. As for the phenyl ether dendrimer, the terminal can be substituted with one having various chemical structures instead of the terminal benzyl ether bond. For example, when synthesizing the dendrimer described in Journal of American Chemistry Vol. 112, various alkyl halides are used in place of the benzyl bromide, a phenyl ether dendrimer having a terminal structure having a corresponding alkyl group can be obtained. In addition, polyamine dendrimers (Macromol. Symp. 77, 21 (1994)) and derivatives obtained by modifying terminal groups thereof can be used.

  As the hyperbranched polymer, for example, hyperbranched polyethylene glycol can be used. A hyperbranched polymer uses a monomer that has two or more kinds of reaction points corresponding to a branched portion and one kind of another reaction point corresponding to a connecting portion in one molecule, and the target polymer in one step. It is obtained by synthesis (Macromolecules, 29 (1996), 3831-3838). For example, a 3,5-dihydroxybenzoic acid derivative is an example of a monomer for a hyperbranched polymer. An example of the production of hyperbranched polymer is 3,5-bis obtained from 1-bromo-8- (t-butyldiphenylsiloxy) -3,6-dioxaoctane and methyl 3,5-dihydroxybenzoate. 3,5-bis ((8'-hydroxy-3 ', 6) which is a hydrolyzate of methyl ((8'-(t-butyldiphenylsiloxy) -3 ', 6'-dioxaoctyl) oxy) benzoate The hyperbranched polymer poly [bis (triethyleneglycol) benzoate] can be synthesized by heating methyl '' -dioxaoctyl) oxy) benzoate with dibutyltin diacetate in a nitrogen atmosphere.

  When 3,5-dihydroxybenzoic acid is used, the hyperbranched polymer terminal group becomes a hydroxyl group, and therefore, hyperbranched polymers having various terminal groups are synthesized by using an appropriate alkyl halide for the hydroxyl group. be able to.

  The properties of monodisperse polymers or hyperbranched polymers with a dendrimer structure are governed by the chemical structure of the main chain and the chemical structure of the terminal group, but the characteristics are particularly dependent on the difference of the substituents in the terminal group and chemical structure. Are very different. Those having a polymerizable group at the terminal are particularly useful because of their reactivity, the gelation effect after photoreaction is great. A dendrimer having a polymerizable group can be obtained by chemically modifying a compound having a polymerizable group at the end of one having a basic atomic group such as an amino group, a substituted amino group, or a hydroxyl group at the end.

  For example, it is synthesized by adding, for example, an isocyanate group-containing vinyl compound to a polyfunctional compound obtained by Michael addition of an active hydrogen-containing (meth) acrylate compound to an amino dendrimer. Moreover, the dendrimer which has a polymerizable group at the terminal is obtained by making (meth) acrylic acid chloride etc. react with an amino dendrimer, for example. Examples of the vinyl compound providing such a polymerizable group include compounds having an ethylenically unsaturated bond capable of radical polymerization. Examples thereof include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, and isocrotonic acid. And compounds having ethylenically unsaturated bonds capable of various radical polymerization described later, such as unsaturated carboxylic acids such as maleic acid and salts thereof.

  Further, examples of the polymerizable group include a terminal group having a cationic polymerizable group, and a polymerizable group that undergoes polymerization by cationic polymerization such as an epoxy group or an oxetanyl group, for example, a cyclic ether such as oxirane or oxetane. Compounds such as alicyclic polyepoxides, polybasic acid polyglycidyl esters, polyhydric alcohol polyglycidyl ethers and the like can be introduced by reacting with the amino dendrimer. For example, chloromethyloxirane can be reacted with an amino dendrimer to introduce an epoxy type cationic polymerizable group at the terminal. In addition, the terminal group includes a cationic polymerizable group selected from styrene derivatives, vinyl naphthalene derivatives, vinyl ethers, N-vinyl compounds, and the like.

  In the present invention, as the polymerizable compound, a compound having an allyl group or a compound having an N-vinyl group is also preferably used.

In the present invention, the compound having an allyl group as a polymerizable compound is a general term for compounds having a ₂ -propenyl structure (—CH ₂ CH═CH ₂ ). The 2-propenyl group is also called an allyl group, and is a common name in the IUPAC nomenclature.
Examples of compounds having an allyl group include allyl glycol (manufactured by Nippon Emulsifier), trimethylolpropane diallyl ether, pentaerythritol triallyl ether, glycerin monoallyl ether (above, Daiso Corporation), UNIOX, UNILOVE, polyserine, and UNISafe. A polyoxyalkylene compound having an allyl group (manufactured by NOF Corporation) and the like.

  In the present invention, examples of the compound having an N-vinyl group include N-vinylformamide, N-vinylcarbazole, N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, and derivatives thereof. Vinylformamide is preferred.

  The coloring material used in the ink composition of the present invention may be either a dye or a pigment, but it suppresses the penetration of the coloring component in the ink composition by the action of insolubilization or thickening of the ink composition. In that case, a dispersed pigment is more advantageous than a dye dissolved in the ink.

As dyes used, direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, reactive disperse dyes, and other various dyes that are usually used in inkjet recording Can be used.
As the pigment to be used, inorganic pigments and organic pigments can be used without any particular limitation.

  As the inorganic pigment, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used. Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye chelates, acidic dye chelates, etc.), nitro pigments, nitroso pigments, aniline black, and the like.

In order to enhance the storage stability of the ink composition as other components, a polymerization inhibitor can be added in an amount of 200 to 20000 ppm. Since the ultraviolet curable ink is preferably ejected by heating and lowering the viscosity, it is preferable to add a polymerization inhibitor in order to prevent clogging of the head due to thermal polymerization.
In addition to this, surfactants, leveling additives, matting agents, polyester resins, polyurethane resins, vinyl resins, acrylic resins, rubber resins, and waxes are added to adjust film properties as necessary. I can do it. In order to improve the adhesion with the recording medium, it is also effective to add a trace amount of organic solvent. In this case, it is effective to add in a range that does not cause the problem of solvent resistance and VOC, and the amount is 0.1 to 5% by mass, preferably 0.1 to 3% by mass.

  In addition, the ink composition of the present invention preferably has a viscosity of 100 mPa · s or less at 25 ° C. in use.

The ink composition of the present invention can be applied to all known and commonly used image recording and printing methods. For example, an image recording / printing method such as an inkjet method, an offset method, a gravure method, or a thermal transfer method can be applied. In particular, the ink composition of the present invention is suitable for ink jet recording.
In the ink jet recording method using the ink composition of the present invention, the ink composition is attached to a recording medium and then irradiated with ultraviolet light. The photo-polymerization initiator generates radicals and the like by the irradiated ultraviolet light, whereby the monomer (or the oligomer, if it contains an oligomer) starts a polymerization reaction, and the ink composition is fixed to the recording medium. Thereby, it is considered that printing that is clear and excellent in film strength and chemical resistance can be performed on the surface of a medium that cannot penetrate an aqueous medium such as metal or plastic.

According to a preferred embodiment of the present invention, when irradiated with ultraviolet rays, the ultraviolet irradiation dose, 100 mJ / cm ² or more, preferably 500 mJ / cm ² or more, also, 10,000 / cm ² or less, preferably 5, 000 mJ / cm ² or less. An ultraviolet irradiation amount within such a range is advantageous because a sufficient curing reaction can be carried out and the colorant can be prevented from fading due to ultraviolet irradiation.

Examples of the ultraviolet irradiation include lamps such as metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, low pressure mercury lamps, and high pressure mercury lamps. For example, a commercially available product such as an H lamp, D lamp, or V lamp manufactured by Fusion System can be used.
Further, ultraviolet irradiation can be performed by an ultraviolet light emitting semiconductor element such as an ultraviolet light emitting diode (ultraviolet LED) or an ultraviolet light emitting semiconductor laser.
In the ink jet recording method using the ink composition of the present invention, heating may be performed simultaneously with or after the irradiation with ultraviolet light.
Heating is performed by bringing a recording medium into contact with a heat source, heating without irradiating the recording medium, such as irradiating infrared rays or microwaves (electromagnetic waves having a maximum wavelength of about 2,450 Mhz), or blowing hot air. The method etc. are mentioned.

Further, the ultraviolet curable ink composition of the present invention can be used by being housed in a known and usual ink container and ink jet recording apparatus.
Furthermore, the present invention can also be applied to clear ink that does not include a color material.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. Those skilled in the art can implement various modifications as well as the following embodiments, and such modifications are also included in the scope of the claims.

[Synthesis Example 1]
(Synthesis of Aliphatic Monomer (A1))
<Synthesis of Precursor A>
A round bottom flask, a powerful stirrer, and an oil bath were prepared. A Dimroth condenser and a dropping funnel that can be sealed with an inert gas were attached to the round bottom flask, and a stirrer chip was further inserted. Then, the interior of the flask was deoxygenated using a vacuum pump. After the inside of the flask was returned to normal pressure with an inert gas, a solution prepared by dissolving 5-bromide pentene (125 g, 0.840 mol) in methanol (250 g) was charged into the flask using a syringe so that oxygen was not mixed. Further, sodium methylate (54.25 g, 1.008 mol) was added to the dropping funnel as a 28 mass% methanol solution (193.75 g) using a syringe so as not to mix oxygen. The alcoholate solution in the dropping funnel was gradually added dropwise to the flask under ice cooling and stirred for 2 hours. Thereafter, stirring was continued for 2 hours at room temperature and overnight at about 50 ° C. It was confirmed by gas chromatography (GC) that no raw material 5-bromopentene remained, and the reaction solution was added to 500 mL of water. This solution was transferred to a 1 L separatory funnel, and 500 mL of hexane was further added. Shake vigorously and take a hexane layer. The hexane layer obtained by repeating the liquid separation operation again was combined with the previously obtained hexane layer and washed with pure water. After washing with pure water again and confirming by GC that no methanol remained, the hexane layer was taken out and dehydrated with sodium sulfate. The mixture was allowed to stand for about 1 hour and then filtered to obtain a hexane solution of the target compound, precursor A. When the mass spectrum was measured by GCMS, it was confirmed that the mass spectrum of the obtained compound had the same characteristics as the mass spectrum described in the literature of the target compound.

<Synthesis of Aliphatic Monomer (A1)>
A round bottom flask and an oil bath were prepared. A Dimroth condenser that can be sealed with an inert gas was attached to the round bottom flask, and a stirrer chip was placed. The inside of the flask was deoxygenated using a vacuum pump. After returning the inside of the flask with an inert gas, the hexane solution of the high-purity olefin compound (precursor A) obtained in the previous reaction was charged into the flask using a syringe so that oxygen was not mixed. Thereafter, about 1.5 times moles or more of dichloromethylsilane (96.6 g or more or 0.840 mol or more) of the olefin compound in the hexane solution was charged into the flask using a syringe so as not to mix oxygen. Further, about 5 drops of a 2% by weight xylene solution of platinum complex was charged using a syringe so that oxygen was not mixed. The system was stirred at room temperature for about 30 hours to complete the reaction. The reaction solution was first distilled at normal pressure. After recovering hexane and residual dichlorosilane, the system was depressurized with a vacuum pump to start distillation of the target silane compound. The target silane compound was obtained at a distillation temperature of 82 to 85 ° C. at about 20 Torr. ¹ HNMR was measured (chloroform was used as a heavy solvent, 400 MHz), and it was confirmed from the chemical shift, branching, and integrated value of the obtained signal that the compound was the target silane compound (aliphatic monomer (A1)) (FIG. 1). reference). In the subsequent polymerization reaction, a purified product obtained by subjecting the main distillate to distillation under reduced pressure was used immediately before. All the solvents used were dried with molecular sieves.

[Synthesis Example 2]
(Synthesis of Aliphatic Monomer (A2))
A round bottom flask and an oil bath were prepared. A Dimroth condenser that can be sealed with an inert gas was attached to the round bottom flask, and a stirrer chip was placed. The inside of the flask was deoxygenated using a vacuum pump. After returning the inside of the flask with an inert gas, the hexane solution of precursor A, which is a high-purity olefin compound synthesized in Synthesis Example 1 above, was charged into the flask using a syringe so that oxygen was not mixed. Thereafter, about 1.5 times moles or more of dichloroethylsilane (108.4 g or more or 0.840 mol or more) of the olefin compound in the hexane solution was charged into the flask using a syringe so as not to mix oxygen. Further, about 5 drops of a 2% by weight xylene solution of platinum complex was charged using a syringe so that oxygen was not mixed. The system was stirred at room temperature for about 30 hours to complete the reaction. The reaction solution was first distilled at normal pressure. After recovering hexane and residual dichlorosilane, the system was decompressed with a vacuum pump to distill the target silane compound. It was confirmed that the target silane compound (aliphatic monomer (A2)) was obtained from the chemical shift, branching, and integral value of the signal obtained by measuring ¹ HNMR. In the subsequent polymerization reaction, a purified product obtained by subjecting the main distillate to distillation under reduced pressure was used immediately before. All the solvents used were dried with molecular sieves.

[Synthesis Example 3]
(Synthesis of aromatic monomer (B1))
Magnesium (15.7 g, 0.645 mol, ground shape) was placed in a 3 L four-necked flask equipped with a Dimroth condenser, dropping funnel, and stirrer, and the atmosphere in the flask was replaced with nitrogen. Diethyl ether (200 mL) was poured into the flask while maintaining a positive pressure with nitrogen, and a piece of iodine was added with stirring. Further, 1-bromo-4-butylbenzene (141.6 g, 0.665 mol) and diethyl ether (500 mL) were placed in a dropping funnel while keeping the inside of the flask at a positive pressure with nitrogen. When diethyl ether was heated and refluxing began, a diethyl ether solution of 1-bromo-4-butylbenzene was dropped from the dropping funnel over about 4.5 hours under gentle reflux, and the mixture was stirred for 1 hour. After heating and stirring, the reaction solution was cooled to room temperature and diluted with 300 mL of toluene. Tetrachlorosilane (44.6 g, 0.263 mol) and toluene (200 mL) were placed in a dropping funnel while keeping the inside of the flask at a positive pressure with nitrogen, and dropped at room temperature over about 30 minutes. After completion of the dropwise addition, stirring of the reaction solution was continued overnight at room temperature. The produced magnesium bromide crystals were filtered, the obtained filtrate was concentrated, and the concentrate was distilled under reduced pressure. 4-Butylphenyltrichlorosilane was obtained as an initial stream, and 48.5 g of light yellow bis (4-butylphenyl) dichlorosilane was obtained as a main fraction (153 to 155 ° C./4 to 5 Torr). ¹ HNMR was measured (chloroform was used as a heavy solvent, 400 MHz), and it was confirmed from the chemical shift, branching, and integral value of the obtained signal that the compound was the target silane compound (aromatic monomer (B1)) (FIG. 2). reference). In the subsequent polymerization reaction, a purified product obtained by subjecting the main distillate to distillation under reduced pressure was used immediately before. All the solvents used were dried with molecular sieves.

[Synthesis Example 4]
(Synthesis of aromatic monomer (B2))
Magnesium (15.7 g, 0.645 mol, ground shape) was placed in a 3 L four-necked flask equipped with a Dimroth condenser, dropping funnel, and stirrer, and the atmosphere in the flask was replaced with nitrogen. Diethyl ether (200 mL) was poured into the flask while maintaining a positive pressure with nitrogen, and a piece of iodine was added with stirring. Further, 1-bromo-4-hexylbenzene (160.9 g, 0.665 mol) and diethyl ether (500 mL) were placed in a dropping funnel while keeping the inside of the flask at a positive pressure with nitrogen. When the flask was heated and refluxing started, 1-bromo-4-hexylbenzene in diethyl ether was added dropwise from the dropping funnel under gentle refluxing in about 4.5 hours and stirred for 1 hour. After heating and stirring, the reaction solution was cooled to room temperature and diluted with toluene. Tetrachlorosilane (44.6 g, 0.263 mol) and toluene (200 mL) were placed in a dropping funnel while keeping the inside of the flask at a positive pressure with nitrogen, and dropped at room temperature over about 30 minutes. After completion of the dropwise addition, the reaction solution was continuously stirred at room temperature overnight. The produced magnesium bromide crystals were filtered, and the obtained filtrate was concentrated. This concentrated liquid was distilled under reduced pressure to obtain bis (4-hexylphenyl) dichlorosilane as a main fraction. It was confirmed that the target silane compound (aromatic monomer (B2)) was obtained from the chemical shift, branching, and integral value of the signal obtained by measuring ¹ HNMR. In the subsequent polymerization reaction, a purified product obtained by subjecting the main distillate to distillation under reduced pressure was used immediately before. All the solvents used were dried with molecular sieves.

[Example 1]
(Synthesis of polysilane compound (1))
A round bottom flask, mechanical stirrer, and oil bath were prepared. A round bottom flask was equipped with a Dimroth condenser that can be sealed with an inert gas, and a stirring rod with a half-moon blade, and the stirring rod was connected to a mechanical stirrer. The flask was deoxygenated using a vacuum pump. After the inside of the flask was returned to normal pressure with an inert gas, bis (4-butylphenyl) dichlorosilane (169.5 g, 0.464 mol), which is the aromatic monomer (B1) prepared in Synthesis Example 3, and Synthesis Example 1 A solution of 5-methoxypentylmethyldichlorosilane (97.93 g, 0.455 mol), which is the aliphatic monomer (A1) prepared in step 3, in 229.1 g of toluene is placed in a flask using a syringe so that oxygen and moisture do not enter. Prepared. Thereafter, metallic sodium (44.10 g, 1.917 mol) stored in mineral oil was charged with an inert gas while keeping the inside of the flask at a positive pressure. Thereafter, the temperature of the reaction system was raised to about 110 ° C., and stirring was continued for about 50 hours.

After about 50 hours, 0.4 times moles of trimethylchlorosilane (39.88 g, 0.3676 mol) of the charged silane compound was charged into the flask using a syringe so as not to mix oxygen, and the reaction was further continued for about 30 hours to complete the reaction. After cooling to room temperature, the reaction solution was filtered to remove insolubles, and the resulting filtrate was added dropwise to methanol to obtain a polymer produced as a precipitate. The yield was 7.63g. ¹ HNMR was measured (chloroform was used as a heavy solvent, 400 MHz), and it was confirmed from the chemical shift, branching, and integrated value of the obtained signal that the compound was the target polysilane compound (1) (see FIG. 3). Furthermore, molecular weight measurement by GPC (eluent THF, flow rate 1 mL / min, detector RI, weight average molecular weight 679,531, number average molecular weight 348,150, polydispersity 1.952, overall monomer ratio 49:51) and UV absorption by spectrophotometer (Measured by preparing a polysilane compound in a dilute THF solution, using THF as a reference, extinction coefficient 5980 of maximum absorption (see FIG. 4)). The obtained polysilane compound (1) was found to have a molecular weight distribution of two peaks. Table 2 shows the molecular weight of the polysilane compound (1) and the extinction coefficient (maximum extinction coefficient) of the maximum absorption at 290 to 410 nm as E # 27.

[Example 2]
(Synthesis of polysilane compound (2))
A round bottom flask, mechanical stirrer, and oil bath were prepared. A round bottom flask was equipped with a mechanical stirrer equipped with a Dimroth condenser that can be sealed with an inert gas and a stirring rod with a half-moon blade. The inside of the flask was deoxygenated using a vacuum pump. After the inside of the flask was returned with an inert gas, the aromatic monomer (B2) prepared in Synthesis Example 4 and bis (4-hexylphenyl) dichlorosilane (192.6 g, 0.464 mol) were prepared in Synthesis Example 1. A solution in which aliphatic monomer (A1) 5-methoxypentylmethyldichlorosilane (97.93 g, 0.455 mol) was dissolved in 229.1 g of toluene was charged into a flask using a syringe so that oxygen was not mixed. Thereafter, metallic sodium (44.10 g, 1.917 mol) stored in mineral oil was charged with an inert gas maintained at a positive pressure in the system. Thereafter, the temperature was raised to about 110 ° C., and the reaction was continued for about 50 hours. After the reaction was continued for about 50 hours, 0.4 times moles of trimethylchlorosilane (39.88 g, 0.3676 mol) of the charged silane compound was charged into the flask using a syringe so as not to be mixed with oxygen. The reaction was further continued for about 30 hours to complete the reaction. After cooling to room temperature, the reaction solution was filtered to remove insoluble matters such as by-products and residual sodium. The filtrate was added dropwise to methanol to obtain a polymer produced as a precipitate. ^From the chemical shift of the signal obtained by measuring ¹ HNMR and the integrated value, it was confirmed to be the target polysilane compound (2).

Example 3
(Synthesis of polysilane compound (3) -1)
A round bottom flask, mechanical stirrer, and oil bath were prepared. A round bottom flask was equipped with a mechanical stirrer equipped with a Dimroth condenser that can be sealed with an inert gas and a stirring rod with a half-moon blade. The inside of the flask was deoxygenated using a vacuum pump. After returning the flask with an inert gas, the aromatic monomer (B1) prepared in Synthesis Example 3 (bis (4-butylphenyl) dichlorosilane (169.5 g, 0.464 mol)) and the aromatic prepared in Synthesis Example 2 were used. A solution prepared by dissolving 5-methoxypentylethyldichlorosilane (58.70 g, 0.455 mol), which is a group-based monomer (A2), in 229.1 g of toluene was charged into a flask using a syringe so as not to mix oxygen. Thereafter, metallic sodium (44.10 g, 1.917 mol) stored in mineral oil was charged with an inert gas maintained at a positive pressure in the system. Thereafter, the temperature was raised to about 110 ° C., and the reaction was continued for about 50 hours. After continuing the reaction for about 50 hours, 0.4 times moles of trimethylchlorosilane (39.88 g, 0.3676 mol) of the charged silane compound was charged into the flask using a syringe so as not to contaminate oxygen. The reaction was further continued for about 30 hours to complete the reaction. After cooling to room temperature, the reaction solution was filtered to remove insoluble matters such as by-products and residual sodium. The filtrate was added dropwise to methanol to obtain a polymer produced as a precipitate. ^From the chemical shift of the signal obtained by measuring ¹ HNMR and the integrated value, it was confirmed to be the target polysilane compound (3).

Example 4
(Synthesis of polysilane compound (3) -2)
A round bottom flask, mechanical stirrer, and oil bath were prepared. A round bottom flask was equipped with a Dimroth condenser that can be sealed with an inert gas, and a stirring rod with a half-moon blade, and the stirring rod was connected to a mechanical stirrer. The flask was deoxygenated using a vacuum pump. After the inside of the flask was returned to normal pressure with an inert gas, bis (4-butylphenyl) dichlorosilane (113.1 g, 0.309 mol), which is the aromatic monomer (B1) prepared in Synthesis Example 3, and Synthesis Example 2 The prepared aromatic monomer (A2) 5-methoxypentylethyldichlorosilane (65.32 g, 0.303 mol) in 152.8 g of toluene was charged into a flask using a syringe so that oxygen and moisture would not be mixed. . Thereafter, metallic sodium (29.41 g, 1.279 mol) stored in mineral oil was charged with an inert gas while keeping the inside of the flask at a positive pressure. Thereafter, the temperature of the reaction system was raised to about 110 ° C., and stirring was continued for about 50 hours. After about 50 hours, 0.4 times moles of trimethylchlorosilane (26.60 g, 0.2452 mol) of the charged silane compound was charged into the flask using a syringe so as not to mix oxygen, and the reaction was further continued for about 30 hours to complete the reaction. After cooling to room temperature, the reaction solution was filtered to remove insolubles, and the resulting filtrate was added dropwise to isopropyl alcohol to obtain a produced polymer as a precipitate. The yield was 6.10g. ^From the chemical shift, branching, and integral value of the signal obtained by measuring ¹ HNMR, it was confirmed to be the desired polysilane compound (3). Furthermore, molecular weight measurement by GPC and UV absorption by a spectrophotometer were measured. The obtained polysilane compound (3) was found to have a molecular weight distribution of two peaks. Table 2 shows the molecular weight of the polysilane compound (3) and the absorption coefficient (maximum absorption coefficient) of the maximum absorption at 290 to 410 nm as E # 26.

Example 5
(Synthesis of polysilane compound (3) -3)
A round bottom flask, mechanical stirrer, and oil bath were prepared. A round bottom flask was equipped with a Dimroth condenser that can be sealed with an inert gas, and a stirring rod with a half-moon blade, and the stirring rod was connected to a mechanical stirrer. The flask was deoxygenated using a vacuum pump. After returning the inside of the flask to normal pressure with an inert gas, bis (4-butylphenyl) dichlorosilane (2.91 g, 0.008 mol), which is the aromatic monomer (B1) prepared in Synthesis Example 3, and Synthesis Example 2 The prepared aromatic monomer (A2) 5-methoxypentylethyldichlorosilane (1.70 g, 0.008 mol) in 0.5 mL of toluene was charged into a flask using a syringe so that oxygen and moisture would not be mixed. . Thereafter, metallic sodium (0.75 g, 0.0326 mol) stored in mineral oil was charged while keeping the inside of the flask at a positive pressure with an inert gas. Thereafter, the temperature of the reaction system was raised to about 110 ° C., and stirring was continued for about 50 hours. After about 50 hours, 0.4 times moles of trimethylchlorosilane (0.6944 g, 0.0064 mol) of the charged silane compound was charged into the flask using a syringe so as not to mix oxygen, and the reaction was further continued for about 30 hours to complete the reaction. After cooling to room temperature, the reaction solution was filtered to remove insolubles, and the resulting filtrate was added dropwise to isopropyl alcohol to obtain a produced polymer as a precipitate. The yield was 7.63g. ^From the chemical shift, branching, and integral value of the signal obtained by measuring ¹ HNMR, it was confirmed to be the desired polysilane compound (3). Furthermore, molecular weight measurement by GPC and UV absorption by a spectrophotometer were measured. The obtained polysilane compound (3) was found to have a molecular weight distribution of two peaks. Table 2 shows the molecular weight of the polysilane compound (3) and the number of extinction coefficients (maximum extinction coefficients) of maximum absorption at 290 to 410 nm as S1010.

[Comparative Example 1]
(Synthesis of comparative polysilane compound (1))
A round bottom flask, mechanical stirrer, and oil bath were prepared. A round bottom flask was equipped with a Dimroth condenser that can be sealed with an inert gas, and a stirring rod with a half-moon blade, and the stirring rod was connected to a mechanical stirrer. The flask was deoxygenated using a vacuum pump. After returning the inside of the flask to normal pressure with an inert gas, bis (4-butylphenyl) dichlorosilane (5.00 g, 0.0164 mol), which is the aromatic monomer (B1) prepared in Synthesis Example 3, was added to 15.0 g of toluene. The dissolved solution was charged into the flask using a syringe so that oxygen and moisture were not mixed. Thereafter, metallic sodium (0.754 g, 0.0328 mol) stored in mineral oil was charged with an inert gas while keeping the inside of the flask at a positive pressure. Thereafter, the temperature of the reaction system was raised to about 110 ° C., and stirring was continued for about 50 hours. After about 50 hours, 0.4 times moles of trimethylchlorosilane (0.712 g, 0.00656 mol) of the charged silane compound was charged into the flask using a syringe so as not to mix oxygen, and the reaction was continued for about 30 hours to complete the reaction. After cooling to room temperature, the reaction solution was filtered to remove insolubles, and the resulting filtrate was added dropwise to methanol to obtain a polymer produced as a precipitate. The yield was 7.63g. ^From the chemical shift, branching, and integral value of the signal obtained by measuring ¹ HNMR, it was confirmed to be the objective comparative polysilane compound (1). Furthermore, molecular weight measurement by GPC and UV absorption by a spectrophotometer were measured. Table 2 shows the molecular weight of the comparative polysilane compound (1) and the extinction coefficient (maximum extinction coefficient) of the maximum absorption at 290 to 410 nm as E # 18.

[Comparative Example 2]
(Synthesis of comparative polysilane compound (2))
A round bottom flask, mechanical stirrer, and oil bath were prepared. A round bottom flask was equipped with a Dimroth condenser that can be sealed with an inert gas, and a stirring rod with a half-moon blade, and the stirring rod was connected to a mechanical stirrer. The flask was deoxygenated using a vacuum pump. After returning the inside of the flask to normal pressure with an inert gas, 5-methoxypentylethyldichlorosilane (0.60 g (2.80 mmol)), which is the aromatic monomer (A2) prepared in Synthesis Example 2, was dissolved in 1.2 g of toluene. The solution was charged into the flask using a syringe so that oxygen and moisture were not mixed. Thereafter, 0.0966 g (4.20 mmol) of metallic sodium stored in mineral oil was charged while keeping the inside of the flask at a positive pressure with an inert gas. Thereafter, the temperature of the reaction system was raised to about 110 ° C., and stirring was continued for about 50 hours. After about 50 hours, 0.4 times moles of trimethylchlorosilane (0.122 g, 1.12 mol) of the charged silane compound was charged into the flask using a syringe so as not to mix oxygen, and the reaction was further continued for about 30 hours to complete the reaction. After cooling to room temperature, the reaction solution was filtered to remove insolubles, and the resulting filtrate was added dropwise to methanol to obtain a polymer produced as a precipitate. The yield was 7.63g. ^From the chemical shift, branching, and integrated value of the signal obtained by measuring ¹ HNMR, it was confirmed to be the objective comparative polysilane compound (2). Furthermore, molecular weight measurement by GPC and UV absorption by a spectrophotometer were measured. The obtained comparative polysilane compound (2) was found to have a molecular weight distribution of two peaks. Table 2 shows the molecular weight of the comparative polysilane compound (2) and the absorption coefficient (maximum absorption coefficient) of the maximum absorption at 290 to 410 nm as E # 5.

  Table 2 below shows the relationship between the molecular weight of the polysilane compounds obtained in the above Examples and Comparative Examples and the extinction coefficient (maximum extinction coefficient) of the maximum absorption at 290 to 410 nm.

  From the relationship between the average molecular weight obtained in Table 2 and the absorption coefficient of maximum absorption, it can be seen that the average molecular weight of polysilane is about 5000 or more and the extinction coefficient exceeds 2000, as shown in FIG. Since the polysilane compound of the formula (1) of the present invention can be synthesized with a higher average molecular weight than the comparative polysilane compound, the light absorption coefficient can be increased, and it can be seen that the activity as a photopolymerization initiator is large.

  Next, examples of the ultraviolet curable ink composition containing the polysilane compound represented by the formula (1) of the present invention are shown.

[Preparation of pigment dispersion]
C. as a colorant I. Pigment black 7 (carbon black) 15 parts by mass, Discol N-509 (manufactured by Dainichi Seika Kogyo Co., Ltd.) as a dispersant to 6.0 parts by mass, ethylene glycol monoallyl ether as a monomer is added to make 100 mass The mixture was mixed and stirred to obtain a mixture. This mixture was subjected to a dispersion treatment for 6 hours together with zirconia beads (diameter 1.5 mm) using a sand mill (manufactured by Yaskawa Seisakusho). Thereafter, the zirconia beads were separated with a separator to obtain a black pigment dispersion ("Pigment Black-7" in Table 3 below).

  In the same manner as described above, a pigment dispersion corresponding to each color, that is, a cyan pigment dispersion (“Pigment Blue-15: 3” in Table 3 below), a magenta pigment dispersion (“Pigment Violet—in Table 3 below) 19 "), a yellow pigment dispersion (" Pigment Yellow-155 "in Table 3 below).

[Example 6: Preparation of ink compositions 1-1 to 1-4: see Table 3 below]
Medol-10 (acrylic monomer: manufactured by Osaka Organic Chemical Industry Co., Ltd.), Biscoat # 360 (polyfunctional monomer, trimethylolpropane modified triacrylate: manufactured by Osaka Organic Chemical Industry Co., Ltd.), polysilane compound obtained in Example 1 (1 ) And a dispersant (polyoxyalkylene polyalkylene polyamine) are mixed in the composition (parts by mass) shown in Table 3 below, and then added to the pigment dispersion (Pigment Black-7, Pigment Blue-15: 3, Pigment Violet). −19, Pigment Yellow-155) was added dropwise with stirring (see Table 3 below for the amount added). After completion of the dropwise addition, the mixture was stirred at room temperature for 1 hour and further filtered through a 5 μm membrane filter to obtain ink compositions 1-1 to 1-4 of Example 6.

Ink compositions 1-1 to 1-4 of Example 6 are shown in Table 3.
Further, “viscosity at 20 ° C. (unit: mPa · s)” of this ink composition was measured and displayed in Table 3. Furthermore, the following “curability test”, “pencil hardness test”, “printing test”, and “storage stability test” were performed, and these test results (evaluations) are also shown in Table 3.

"Curability test"
The ink compositions of Examples 1-1 to 1-4 were dropped on a glass substrate, and ultraviolet rays with a wavelength of 365 nm, irradiation intensity of 17 mW / cm ² , irradiation time of 6 seconds, and integrated light quantity of 102 mJ / cm ^{2 were} short and low. After performing the curing process under the curing condition of the light amount, the following evaluation index (visual evaluation of curability) was used.
Evaluation index ○: Completely cured.
Δ: Almost cured but not complete.
X: Only a part is cured.

"Pencil hardness test"
Hardness evaluation was performed by the method prescribed | regulated to JISK5400 (pencil scratch test handwriting method) with respect to the sample which performed the hardening process by the said method.

"Print test"
Using an ink jet printer PX-G900 manufactured by Seiko Epson Corporation and using the ink compositions of Examples 1-1 to 1-4, an OHP film (manufactured by Fuji Xerox Co., Ltd.) After performing solid pattern printing using XEROX FILM <no frame>), and performing printing and curing processing under curing conditions such that the integrated light quantity is 90 mJ / cm ² by an ultraviolet irradiation device installed at the paper discharge port Evaluation was made with the following evaluation index (visual evaluation of curability).
Evaluation index (circle): An ink composition hardens | cures on a thin film on an OHP film.
X: The ink composition is not completely cured on the OHP film.

"Storage stability test"
The photocurable ink composition is left in an environment of 60 ° C. × 7 days, and the initial viscosity (mPa · s) and the viscosity after being left are measured with a rheometer (manufactured by Physica, MCR-300). Then, the rate of change in viscosity was evaluated by the following index. The initial viscosity and the viscosity after standing were measured at 20 ° C.

AA: The rate of change between the initial viscosity and the viscosity after standing is less than ± 5%.
A: Change rate of initial viscosity and viscosity after standing is ± 5% or more and less than ± 20%.
B: The rate of change between the initial viscosity and the viscosity after standing is ± 20% or more.

[Example 7: Preparation of ink compositions 2-1 to 2-4: see Table 4 below]
Medol-10, Biscote # 360, the polysilane compound (2) obtained in Example 2, the dispersant (polyoxyalkylene polyalkylene polyamine), and the pigment dispersion were formulated into the compositions shown in Table 4 below, and then 1 at room temperature. The mixture was stirred for an hour and further filtered through a 5 μm membrane filter to obtain ink compositions 2-1 to 2-4 of Example 7.

Ink compositions 2-1 to 2-4 of Example 7 are shown in Table 4.
As in Example 6, Table 4 shows the results of “viscosity at 20 ° C. (unit: mPa · s)”, “curability test”, “pencil hardness test”, “printing test”, and “storage stability test” of this ink composition. Displayed.

[Example 8: Preparation of ink compositions 3-1 to 3-4: See Table 5 below]
Example using allyl glycol (manufactured by Nippon Emulsifier), N-vinylformamide (manufactured by Daianitrix) and biscort # 1000 (manufactured by Osaka Organic Chemical Industries) which is a dendritic polymer having a (meth) acryloyl group as a polymerizable compound The polysilane compound (3), the dispersant, and the pigment dispersion obtained in Step 3 were mixed into the composition shown in Table 5 below, mixed and stirred at room temperature for 1 hour, and filtered through a 5 μm membrane filter. Ink compositions 3-1 to 3-4 were obtained.

Ink compositions 3-1 to 3-4 of Example 8 are shown in Table 5.
As in Example 6, Table 5 shows the results of “viscosity at 20 ° C. (unit: mPa · s)” and “curability test”, “pencil hardness test”, “printing test”, and “storage stability test” of this ink composition. Displayed.

[Comparative Example 3: Preparation of Comparative Ink Compositions 1-1 to 1-4: See Table 6 below]
The polysilane compound (E # 18) synthesized in Comparative Example 1 was used as a photopolymerization initiator, and the other components were made the same as in Example 6 to prepare the composition shown in Table 6 below, followed by mixing and stirring at room temperature for 1 hour. Further, the mixture was filtered through a 5 μm membrane filter to obtain comparative ink compositions 1-1 to 1-4 of Comparative Example 3.

[Comparative Example 4: Preparation of Comparative Ink Compositions 2-1 to 2-4: See Table 7 below]
Irgacure 1800 (Ciba Specialty Chemicals Co., Ltd.) was used instead of polysilane as a photopolymerization initiator, and the other components were the same as in Example 8 and formulated into the composition shown in Table 7 below, followed by mixing and stirring at room temperature for 1 hour. Further, the mixture was filtered through a 5 μm membrane filter to obtain comparative ink compositions 2-1 to 2-4 of Comparative Example 4.

Table 6 shows comparative ink compositions 1-1 to 1-4 of Comparative Example 3, and Table 7 shows comparative ink compositions 2-1 to 2-4 of Comparative Example 4.
As in Examples 6 and 8, the “viscosity at 20 ° C. (unit: mPa · s)” of these ink compositions and the results of “curability test”, “pencil hardness test”, “printing test”, and “storage stability test” are shown. Displayed in Tables 6 and 7.

2 is a ¹ HNMR chart of a dichlorosilane compound (aliphatic monomer (A1)) obtained in Synthesis Example 1. FIG. 2 is a ¹ HNMR chart of a dichlorosilane compound (aromatic monomer (B1)) obtained in Synthesis Example 3. FIG. 1 is a ¹ HNMR chart of a polysilane compound (1) obtained in Example 1. 2 is an absorption spectrum of the polysilane compound (1) obtained in Example 1. It is a graph which shows the influence with respect to the light absorption coefficient (maximum light absorption coefficient) of the maximum absorption in 290-410 nm of the average molecular weight of the synthesized polysilane.

Claims (9)

A polysilane compound having a structure represented by the following formula 1.

[In Formula 1, m and n represent a molar ratio, and m + n = 1 is a positive number. p represents an integer of 2 or more and 10 or less. q represents an integer of 0 or more and 5 or less.
R1 is, _{-CH 2} CH 2 - or _-CH 2 CH (CH ₃₎ - represents a.
R2 and R3 each independently represents an alkyl group having 1 to 12 carbon atoms, a phenyl group, or a benzyl group. The phenyl group and benzyl group may be further substituted with a substituent X1.
R4 represents a phenyl group. The phenyl group may be further substituted with a substituent X1.
R5 represents an alkyl group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, a halogen group, a cyano group, an acyl group, an acyloxy group, a benzoyl group, and a nitro group.
The substituent X1 represents an alkyl group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, a halogen group, a cyano group, an acyl group, an acyloxy group, a benzoyl group, and a nitro group. ]   2. The polysilane compound according to claim 1, wherein a maximum extinction coefficient of 290 nm to 410 nm is 1000 or more.   The polysilane compound according to claim 1 or 2, wherein the average molecular weight is 5000 or more.   The polysilane compound according to claim 1, which is soluble in a hydrophilic acrylate.   The method for synthesizing a polysilane compound according to any one of claims 1 to 4, wherein a monomer is synthesized using bromide as a starting material and then copolymerized using the monomer.   The ultraviolet curable ink composition containing the polysilane compound as described in any one of Claims 1-4.   An inkjet recording method using the ultraviolet curable ink composition according to claim 6.   An ink container containing the ultraviolet curable ink composition according to claim 6.   An ink jet recording apparatus comprising the ultraviolet curable ink composition according to claim 6.

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