JP6167458B2 - Inkjet ink - Google Patents

Description

  The present invention relates to an active energy ray-curable inkjet ink that is cured by irradiation with active energy rays such as ultraviolet rays.

  For example, an active energy ray-curable inkjet ink that is cured by irradiating active energy rays such as ultraviolet rays is used to print images and characters on the surface of various printed materials such as plastic films by an inkjet printing method. It is done. Recently, in order to cure the inkjet ink by irradiation with ultraviolet rays, it has been studied to reduce energy consumption in the entire printing system by using an LED instead of a conventional UV lamp as a light source.

  Examples of the active energy ray-curable inkjet ink include a compound having two or more oxetane rings in the molecule (hereinafter sometimes abbreviated as “oxetane ring-containing compound”), an epoxy resin such as bisphenol A, and the like. In addition, two types of compounds having one or more oxirane rings in the molecule (hereinafter sometimes abbreviated as “oxirane ring-containing compounds”) are used in combination, and cationic polymerization of these two types of compounds by irradiation with active energy rays The thing which mix | blended the polymerization initiator for starting this is known (patent document 1 etc.).

In addition, an ink-jet ink is also known in which three types obtained by adding epoxidized fatty acid glyceride to these two types are used in combination (Patent Document 2, etc.).
However, these ink-jet inks have low curability and have a problem that they cannot be cured quickly by irradiation with ultraviolet rays from, for example, LEDs.
When a relatively low molecular weight alicyclic epoxide such as limonene dioxide is used as the oxirane ring-containing compound, for example, the low molecular weight alicyclic epoxide has a higher reaction rate than an epoxy resin and is used in combination. Coupled with the high reaction rate of the oxetane ring-containing compound, the curability of the ink-jet ink can be improved, and it can be cured rapidly and sufficiently even by irradiation with ultraviolet rays from the LED.

However, such ink-jet ink has insufficient flexibility of the cured product, resulting in a decrease in printing scratch resistance, and when a local load is applied, printing is applied from the interface with the printing medium. There is a problem that it becomes easy to peel locally along the trajectory.
When epoxidized fatty acid glyceride is used in combination as described in Patent Document 2, the flexibility of the cured product can be improved and the scratch resistance of printing can be improved. The fixing property to the surface is lowered, and printing causes a new problem that the printing is largely peeled from the interface with the printing medium .

Patent Document 3 describes an ink-jet ink that uses a vinyl ether compound instead of an oxirane ring-containing compound. Since the vinyl ether compound has a high reaction rate, the curability of the ink-jet ink is also improved, and it can be cured quickly and sufficiently even by irradiation with ultraviolet rays from the LED.
However, since vinyl ether compounds easily react with acids, for example, when carbon black treated with an acid to increase dispersibility is used as a general pigment for inkjet inks, the storage stability of inkjet inks decreases. is there.

  In addition, since the reaction rate of the vinyl ether compound is too high, for example, when the inkjet ink is cured by passing under a light source such as a UV lamp while feeding a printed material, it reaches the light source due to light leaked from the light source. There is also a problem that the ink-jet ink has already been cured by that time, and that the ink cannot be completely cured until it is completely cured, resulting in insufficient curing.

Japanese Patent No. 2679586 JP 2005-154679 A JP 2010-7000 A

  The object of the present invention is high in curability, and can be cured quickly and sufficiently, for example, by irradiation with ultraviolet rays from an LED, and is excellent in storage stability regardless of the type of pigment. It is an object of the present invention to provide a novel active energy ray-curable ink-jet ink which is excellent in flexibility and the accompanying scratch resistance of printing, heat resistance and fixing property of the printing.

The present invention
(A) alicyclic epoxide,
(B) Epoxidized fatty acid glyceride,
(C) three oxirane ring-containing compounds of a trivalent epoxide having a triazine ring as a skeleton,
An inkjet ink comprising an oxetane ring-containing compound, and a polymerization initiator that initiates cationic polymerization of the oxirane ring-containing compound and the oxetane ring-containing compound by irradiation with active energy rays.

According to the present invention, both the oxetane ring-containing compound having a high reaction rate and the alicyclic epoxide (A) are used in combination, so that the curability of the ink-jet ink is improved, for example, rapidly by irradiation with ultraviolet rays from an LED. And can be cured sufficiently.
Moreover, the combined use of the epoxidized fatty acid glyceride (B) can improve the flexibility of the cured product and improve the scratch resistance of printing.

By using a trivalent epoxide having a triazine ring in the skeleton (C) (hereinafter sometimes abbreviated as “triazine ring-containing epoxide”) in combination, the heat resistance of printing and the fixing property to the printing medium are improved. It becomes possible to improve.
In addition, the ink-jet ink of the present invention comprises (B) the epoxidized fatty acid glyceride and (C) the triazine ring-containing epoxide in total, which is 20 mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It is preferable to contain it in the ratio of% or more and 65 mass% or less.

When the blending ratio is less than this range, the combined use of the epoxidized fatty acid glyceride (B) improves the flexibility of the cured product and improves the scratch resistance of printing, and the triazine ring (C). There is a possibility that the effect of improving the heat resistance of printing and the fixing property to the printing medium by using the epoxide in combination may not be sufficiently obtained.
On the other hand, if the range is exceeded, the ratio of the alicyclic epoxide (A) is relatively small, and the curability of the inkjet ink may be lowered.

The ink-jet ink of the present invention contains (B) the epoxidized fatty acid glyceride and (C) the triazine ring-containing epoxide at a mass ratio of B / C = 1/4 to 1 / 0.5. Is preferred.
When the epoxidized fatty acid glyceride of (B) is less than this range, the combined use of the epoxidized fatty acid glyceride is sufficient to improve the flexibility of the cured product and to improve the scratch resistance of printing. May not be obtained.

On the other hand, when the triazine ring-containing epoxide (C) is less than the range, the combined use of the triazine ring-containing epoxide can sufficiently obtain the effect of improving the heat resistance of printing and the fixability to the printing medium. There is a risk of not.
The triazine ring-containing epoxide of (C) has a structure in which a hydrocarbon group having an epoxy group at each end is substituted on the three nitrogen atoms of the 1,3,5-triazine ring, formula (1):

[Wherein m, n and p are not 0, and m + n + p represents a number of 3 to 20. ]
The compound represented by these is preferable.

  According to the present invention, the curability is high, for example, it can be cured quickly and sufficiently even by irradiation with ultraviolet rays from an LED, and it has excellent storage stability regardless of the type of pigment, and further, It is possible to provide a novel active energy ray-curable ink-jet ink which is excellent in flexibility and the accompanying scratch resistance of printing, heat resistance and fixing property of the printing.

The inkjet ink of the present invention is
(A) alicyclic epoxide,
(B) Epoxidized fatty acid glyceride,
(C) three oxirane ring-containing compounds of a triazine ring-containing epoxide,
It comprises an oxetane ring-containing compound, and a polymerization initiator that initiates cationic polymerization of the oxirane ring-containing compound and the oxetane ring-containing compound by irradiation with active energy rays.

<< oxirane ring-containing compound >>
<Alicyclic epoxide>
The alicyclic epoxide (A) is obtained by epoxidizing at least one compound having a cycloalkane ring such as a cyclohexene ring or a cyclopentene ring with an appropriate oxidizing agent such as hydrogen peroxide or peracid. For example, various compounds containing cyclohexene oxide, cyclopentene oxide and the like can be mentioned.

  Specific examples of the alicyclic epoxide include one or more compounds represented by the formulas (2) to (17).

As the alicyclic epoxide, in consideration of suppressing the increase in the viscosity of the ink jet ink and improving the ejection property from the nozzle of the ink jet printer, those having a molecular weight of 250 or less among the above various compounds, specifically One or more of the compounds represented by the formulas (2) to (8) are preferably used.
Among these, in consideration of the balance between the effect of suppressing the viscosity and the reaction rate, 1,2,8,9-diepoxy limonene (limonene dioxide) represented by the formula (4) is an alicyclic group of (A). It is particularly preferably used as an epoxide.

<Epoxidized fatty acid glyceride>
As the epoxidized fatty acid glyceride (B), one or more of epoxidized soybean oil, epoxidized linseed oil, epoxidized castor oil, etc. produced by epoxidizing soybean oil, linseed oil, castor oil, etc. Is mentioned.
Among these, epoxidized soybean oil is particularly preferably used as the epoxidized fatty acid glyceride (B) from the viewpoint of improving the flexibility of the cured product and improving the scratch resistance of printing.

<Triazine ring-containing epoxide>
The triazine ring-containing epoxide of (C) has a structure in which a hydrocarbon group having an epoxy group at each end is substituted on the three nitrogen atoms of the 1,3,5-triazine ring, formula (1):

[Wherein m, n and p are not 0, and m + n + p represents a number of 3 to 20. ]
The compound represented by these is mentioned.
Specific examples of such triazine ring-containing epoxides include, for example, TEPIC-VL [m + n + p in formula (1): 8 to 13, epoxy equivalent: 125 to 145 g in a TEPIC (registered trademark) series manufactured by Nissan Chemical Industries, Ltd. / Eq, viscosity 6000-8000 mPa · s], TEPIC-G [m + n + p: 5-6, epoxy equivalent: 110 g / eq or less], TEPIC-S [m + n + p: 4-5, epoxy equivalent: 105 g / eq or less], TEPIC -SP [m + n + p: 4-5, epoxy equivalent: 105 g / eq or less], TEPIC-SS [m + n + p: 3-4, epoxy equivalent: 102 g / eq or less], etc.

Among these, in consideration of further improving the heat resistance of printing and the effect of improving the fixing property to the printing medium, a compound in which m + n + p in the formula is 6 to 15 in the above range is preferable, in particular, TEPIC− VL is preferably used as the triazine ring-containing epoxide of (C).
<Combination ratio>
In the ink-jet ink of the present invention, if the three oxirane ring-containing compounds (A) to (C) described above are used in combination, the blending ratio of the three compounds is not particularly limited. The total blending ratio of the epoxidized fatty acid glyceride of (C) and the triazine ring-containing epoxide (C) is 20% by mass to 65% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). Preferably there is.

When the blending ratio is less than this range, the combined use of the epoxidized fatty acid glyceride (B) improves the flexibility of the cured product and improves the scratch resistance of printing, and the triazine ring (C). There is a possibility that the effect of improving the heat resistance of printing and the fixing property to the printing medium by using the epoxide in combination may not be sufficiently obtained.
On the other hand, if the range is exceeded, the ratio of the alicyclic epoxide (A) is relatively small, and the curability of the inkjet ink may be lowered.

On the other hand, by keeping the blending ratio in the above range, while maintaining the high curability of the inkjet ink, the flexibility of the cured product and the accompanying scratch resistance of printing, the heat resistance of the printing, and the fixing property Can be further improved.
The ink-jet ink of the present invention contains (B) the epoxidized fatty acid glyceride and (C) the triazine ring-containing epoxide at a mass ratio of B / C = 1/4 to 1 / 0.5. Is preferred.

When the epoxidized fatty acid glyceride of (B) is less than this range, the combined use of the epoxidized fatty acid glyceride is sufficient to improve the flexibility of the cured product and to improve the scratch resistance of printing. May not be obtained.
On the other hand, when the triazine ring-containing epoxide (C) is less than the range, the combined use of the triazine ring-containing epoxide can sufficiently obtain the effect of improving the heat resistance of printing and the fixability to the printing medium. There is a risk of not.

On the other hand, by setting the blending ratio within the above range, the flexibility of the cured product and the accompanying scratch resistance of printing, the heat resistance and fixing property of the printing can be further improved.
In the present invention, as the oxirane ring-containing compound, other oxirane ring-containing compounds other than the three types (A) to (C) can be used in combination. However, considering that the effects of the three oxirane ring-containing compounds (A) to (C) described above are further improved, the oxirane ring-containing compound includes three kinds (A) to (C). It is preferable to use only the oxirane ring-containing compound.

<Oxetane ring-containing compound>
As the oxetane ring-containing compound, any of various compounds having an oxetane ring in the molecule and capable of cationic polymerization together with the oxirane ring-containing compound by the action of the polymerization initiator can be used.
Examples of such oxetane ring-containing compounds include those represented by the formula (18):

[In formula, R < ¹ >, R < ² > is the same or different, and shows a hydrogen atom, a fluorine atom, a C1-C6 alkyl group, a C1-C6 fluoroalkyl group, an allyl group, an aryl group, or a furyl group. . ]
The compound represented by these is mentioned.
Examples of the oxetane ring-containing compound also include a compound represented by the formula (19).

In the formula, R ³ represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, or a furyl group. R ⁴ is a polyvalent group represented by Formula (20), Formula (21), Formula (22), or Formula (23), and q represents a number of 2 to 4.

In formula (20), R ⁵ represents an alkyl group having 1 to 3 carbon atoms.
In the formula (21), R ⁶ is an alkyl group having 1 to 10 carbon atoms, or the formula (24):

^{Wherein, R 10} represents an alkyl group having 1 to 10 carbon atoms, j is a number of 0 to 100. ]
The group represented by these is shown. R ⁷ represents an alkyl group having 1 to 10 carbon atoms. r shows the number of 0-2000.
In the formula (22), R ⁸ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, a halogen atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxylate group, or a carboxyl group Indicates a group.

In the formula (23), R ⁹ represents an oxygen atom, a carbon atom, a —NH— group, a —SO— group, a —SO ₂ — group, a —CH ₂ — group, a —C (CH ₃ ) ₂ — group, or a —C a group - (CF _{3) 2.}
Examples of the oxetane ring-containing compound also include a compound represented by the formula (25).

[Wherein, R ¹¹ represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, or a furyl group, and R ¹² represents 1 carbon atom. -10 alkyl groups. R ¹³ represents an alkyl group having 1 to 4 carbon atoms or a trialkylsilyl group. k shows the number of 25-200. ]
As the oxetane ring-containing compound, a compound represented by the formula (18) among the above-mentioned various compounds is preferable in consideration of suppressing an increase in the viscosity of the inkjet ink and improving dischargeability from the nozzle of the inkjet printer. Used for.

Among these, considering the balance between the viscosity suppressing effect and the reaction rate, R ¹ and R ² in the formula (18) are both ethyl groups, and 3-ethyl-3 {[(3-ethyloxetane-3- Yl) methoxy] methyl} oxetane is particularly preferably used as the oxetane ring-containing compound.
The blending ratio of the oxetane ring-containing compound is preferably 50 parts by mass or more, particularly preferably 60 parts by mass or more, more preferably 300 parts by mass or less, particularly preferably 270 parts by mass or less, per 100 parts by mass of the oxirane ring-containing compound. .

When the blending ratio is less than this range, there is a possibility that the effect of improving the reaction rate of the inkjet ink by using the oxetane ring-containing compound in combination is not sufficiently obtained.
When the range is exceeded, the blending ratio of the three types of oxirane ring-containing compounds (A) to (C) is relatively reduced, and the explanation is made by using the three types of oxirane ring-containing compounds in combination. There is a risk that the effect obtained will not be sufficiently obtained.

On the other hand, by making the blending ratio of the oxetane ring-containing compound in the above range, the reaction rate of the inkjet ink is further improved while maintaining the effect of using the three oxirane ring-containing compounds in combination. Can do.
<Polymerization initiator>
As a polymerization initiator (photoacid generator) for generating an acid by irradiation of active energy rays such as ultraviolet rays and initiating cationic polymerization of an oxirane ring-containing compound and an oxetane ring-containing compound, various compounds having the above functions can be used. It can be used.

Examples of the polymerization initiator include salts of aromatic onium compounds containing onium ions such as diazonium, ammonium, iodonium, sulfonium phosphonium, and the like.
Examples of the anion constituting the salt together with the aromatic onium compound include one or more of B (C ₆ F ₅ ) ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , CF ₃ SO ₄ ^{− and the} like. Can be mentioned.

  Specific examples of the polymerization initiator include at least one compound represented by formulas (26) and (27).

X in each formula is one or more of the anions described above.
Among others, wherein it is represented by (26), X in the formula PF ₆ ^- Table mono sulfonium salts [San-Apro Co., Ltd. CPI-100P, 50% propylene carbonate solution] and is, likewise the formula (26) A monosulfonium salt (CPI-101A, 50% propylene carbonate solution manufactured by San Apro Co., Ltd.) in which X in the formula is SbF ₆ ^— is particularly preferably used as the polymerization initiator.

The blending ratio of the polymerization initiator can be set arbitrarily, but considering that the inkjet ink is efficiently and rapidly cured by irradiation with active energy rays, the total amount of the three oxirane ring-containing compounds and the oxetane ring-containing compound is considered. It is preferably 1% by mass or more, particularly 2% by mass or more, and preferably 10% by mass or less, particularly preferably 8% by mass or less.
In addition, when using the solution of the monosulfonium salt illustrated previously as a polymerization initiator, the compounding ratio of a solution is adjusted so that the compounding ratio of the active ingredient (monosulfonium salt) in the said solution may become said range. do it.

《Other ingredients》
In addition to the above components, the inkjet ink of the present invention may further contain a sensitizer, a colorant, and other components as necessary.
<Sensitizer>
Examples of the sensitizer include various compounds having a function of promoting acid generation of the polymerization initiator by irradiation with active energy rays in a specific wavelength range.

  Examples of such a sensitizer include anthracene derivatives such as 9,10-dibutoxyanthracene when the active energy ray is ultraviolet light from an LED. Other sensitizers include, for example, anthracene, pyrene, perylene, acridine orange, thioxanthone, and 2-chlorothioxanthone disclosed in Crivello [JV Crivello, Adv. In Polymer Sci., 62, 1 (1984)]. And benzoflavin.

In addition, as a sensitizer, what has the absorption wavelength range suitable for sensitization according to the wavelength range of an active energy ray and the absorption wavelength range of a polymerization initiator can be used individually by 1 type, respectively, 2 types You may use the above together.
Although the blending ratio of the sensitizer can be arbitrarily set, in consideration of obtaining a good sensitizing effect, it is 1% by mass or more, particularly 2% by mass with respect to the total amount of the three oxirane ring-containing compounds and the oxetane ring-containing compound. % Is preferable, and it is preferably 10% by mass or less, particularly preferably 6% by mass or less.

<Colorant>
Examples of the colorant include various pigments and dyes. As the colorant, any colorant corresponding to the color of the inkjet ink can be used. In particular, various inorganic pigments and / or organic pigments are preferable in consideration of improving the light resistance, weather resistance and the like of printing.

Among these, as inorganic pigments, various carbon blacks such as metal compounds such as titanium oxide and iron oxide, or neutral, acidic, basic, etc. produced by known methods such as contact method, furnace method, thermal method, etc. 1 type, or 2 or more types.
Examples of organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, or chelate azo pigments), and polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), dye chelates (eg basic dye chelate, acid dye chelate, etc.), nitro pigments, nitroso pigments, aniline black, etc. Can be mentioned.

One or more inorganic or organic pigments can be used depending on the color of the inkjet ink. For example, when black is expressed with carbon black, a cyan pigment may be added in order to make it appear more blue.
The surface of the pigment may be treated to improve the dispersion stability in the inkjet ink.

Specific examples of the pigment include the following various pigments.
(Yellow pigment)
C. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 14C, 16, 17, 20, 24, 73, 74, 75, 83, 86, 93, 94, 95, 97, 98, 109, 110, 114, 117, 120, 125, 128, 129, 130, 137, 138, 139, 147, 148, 150, 151, 154, 155, 166, 168, 180, 185, 213, 214
(Magenta pigment)
C. I. Pigment Red 5, 7, 9, 12, 48 (Ca), 48 (Mn), 49, 52, 53, 57 (Ca), 57: 1, 97, 112, 122, 123, 149, 168, 177, 178 179, 184, 202, 206, 207, 209, 242, 254, 255
(Cyan pigment)
C. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 3, 15: 4, 15: 6, 15:34, 16, 22, 60
(Black pigment)
C. I. Pigment Black 7
(Orange pigment)
C. I. Pigment Orange 36, 43, 51, 55, 59, 61, 71, 74
(Green pigment)
C. I. Pigment Green 7, 36
(Violet pigment)
C. I. Pigment Violet 19, 23, 29, 30, 37, 40, 50
As the colorant, a fluorescent dye that is substantially invisible in the visible light region (wavelength 400 to 700 nm) and is excited by ultraviolet light having a wavelength of less than 400 nm to emit visible light can be used.

(Fluorescent dye)
As the fluorescent dye, one that emits red light (preferably wavelength 615 ± 20 nm), which can use an inexpensive silicon photodiode or the like for detection of light emission, is preferably used.
The fluorescent dye includes europium having an emission center wavelength in such a wavelength range, and this includes tenoyl trifluoroacetone, naphthoyl trifluoroacetone, benzoyl trifluoroacetone, methyl benzoyl trifluoroacetone, furoyl trifluoroacetone, pivaloyl trifluoroacetate. Examples thereof include one or more metal complexes having a ligand of fluoroacetone, hexafluoroacetylacetone, trifluoroacetylacetone, fluoroacetylacetone, heptafluorobutanoylpivaloylmethane, or the like.

Of these, a europium compound having a ligand of tenoyl trifluoroacetone, naphthoyl trifluoroacetone, or methylbenzoyl trifluoroacetone having high emission intensity is preferable.
Further, for the purpose of improving the emission intensity of printing and ink storage stability, a phosphorus-based organic compound can be used as a part of the ligand of the europium compound.

  Examples of phosphorus organic compounds include triethylphosphine oxide, tri-n-propylphosphine oxide, tri-n-butylphosphine oxide, tri-n-hexylphosphine oxide, tri-n-octylphosphine oxide, triphenylphosphine oxide, tris Phosphine oxide compounds such as (3-hydroxymethyl) phosphine oxide and tris (3-hydroxypropyl) phosphine oxide, phosphine sulfide compounds such as tri-n-butylphosphine sulfide, triethylphosphine, tri-n-propylphosphine, tri-n -Butylphosphine, tri-n-hexylphosphine, tri-n-octylphosphine, triphenylphosphine, tris (3-hydroxypropyl) phospho One or more phosphine compounds such as fins and the like.

Depending on the application, organic fluorescent dyes that are practically invisible in the visible light region and that are excited by ultraviolet rays and emit visible light other than red, such as blue, green, yellow-green, and yellow can also be used.
Examples of such organic fluorescent dyes include various fluorescent brighteners such as coumarin, stilbene, triazine, imidazole, thiazole, oxazole, pyrazolone and benzoxazine, and rare earth elements such as TVium and thulium. And one or more of metal complexes having a ligand having a large number of π electrons as a counter ion.

(Mixing ratio)
The blending ratio of the colorant is preferably 0.1% by mass or more, particularly 0.4% by mass or more, more preferably 8% by mass or less, and particularly preferably 5% by mass or less, based on the total amount of the inkjet ink.
<Pigment dispersant>
When the colorant is a pigment, in order to disperse the pigment, a pigment dispersant may be added to the inkjet ink. As the pigment dispersant, any of various pigment dispersants such as a polymer pigment dispersant and a surfactant can be used.

The blending ratio of the pigment dispersant is preferably 20% by mass or more, particularly preferably 30% by mass or more, and more preferably 70% by mass or less, particularly preferably 60% by mass or less of the pigment amount.
<Preparation of inkjet ink>
In order to prepare the ink-jet ink of the present invention, for example, a pigment is blended with a predetermined amount of a pigment dispersant in a part of the liquid component of the three oxirane ring-containing compounds and the oxetane ring-containing compound described above. Thus, a pigment dispersion is prepared.

Next, the pigment dispersion is blended with the above three kinds of oxirane ring-containing compounds, the remainder of the oxetane ring-containing compound, a polymerization initiator, and a sensitizer, whereby the inkjet ink of the present invention is prepared.
According to the present invention, by using the above three kinds of oxirane ring-containing compounds and oxetane ring-containing compounds in combination, the curability is high, and for example, it can be cured quickly and sufficiently even by irradiation with ultraviolet rays from an LED. Active energy ray curable type that has excellent storage stability regardless of the type of pigment, and also has excellent flexibility of the cured product and the resulting scratch resistance of printing, as well as heat resistance and fixing properties of the printing. Ink-jet inks can be provided.

<Example 1>
As the alicyclic epoxide of (A), 1,2,8,9-diepoxy limonene represented by the formula (4) [Limonene Dioxide, Celoxide (registered trademark) 3000 manufactured by Daicel Corporation] is used. It was.
As the epoxidized fatty acid glyceride (B), epoxidized soybean oil [Adekasizer (registered trademark) O-130P manufactured by ADEKA Corporation] was used.

As the triazine ring-containing epoxide of (C), m + n + p in the formula (1) is 8 to 13, and the above-mentioned TEPIC-VL manufactured by Nissan Chemical Industries, Ltd. [epoxy equivalent: 125 to 145 g / eq, viscosity 6000 to 8000 mPa · s] was used.
As the oxetane ring-containing compound, 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane [Aron oxetane (registered trademark) OXT-221 manufactured by Toagosei Co., Ltd.] was used. .

As the polymerization initiator, wherein X is PF ₆ in (26) ^- with a a monosulfonium salt [supra San-Apro Co., Ltd. CPI-100P, 50% propylene carbonate solution], as a sensitizer 9,10-dibutoxyanthracene [Anthracure (registered trademark) UVS-1331 manufactured by Kawasaki Kasei Kogyo Co., Ltd.] was used.
Further, as the pigment dispersant, a polymer pigment dispersant [Ajispur (registered trademark) PB822 manufactured by Ajinomoto Fine Techno Co., Ltd.] was used.

(Preparation of pigment dispersion)
Carbon black LFF as a pigment [MA8 manufactured by Mitsubishi Chemical Co., Ltd.] 1.8 parts by mass, 0.7 part by mass of a polymeric pigment dispersant, and 9.5 parts by mass of an oxetane ring-containing compound are mixed and mixed. A pigment dispersion was prepared.
(Preparation of inkjet ink)
25.0 parts by mass of (A) alicyclic epoxide described above, 5.0 parts by mass of epoxidized fatty acid glyceride (B), 10.0 parts by mass of triazine ring-containing epoxide (C), and oxetane ring-containing 40.0 parts by mass of a compound is blended with 5.0 parts by mass of a polymerization initiator (amount of active ingredient: 2.5 parts by mass), 3.0 parts by mass of a sensitizer, and 12.0 parts by mass of a pigment dispersion, After mixing, the mixture was filtered using a 5 μm membrane filter to prepare an inkjet ink.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 37.5% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. The mass ratio B / C of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 1/2.
<Example 2>
The blending amount of the alicyclic epoxide (A) is 32.0 parts by mass, the blending amount of the epoxidized fatty acid glyceride (B) is 2.7 parts by mass, and the blending amount of the triazine ring-containing epoxide (C) is 5. An inkjet ink was prepared in the same manner as in Example 1 except that the amount was 3 parts by mass.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 20.0% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. The mass ratio B / C of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 1/2.
<Example 3>
The blending amount of the alicyclic epoxide (A) is 14.0 parts by mass, the blending amount of the epoxidized fatty acid glyceride (B) is 8.7 parts by mass, and the blending amount of the triazine ring-containing epoxide (C) is 17. An inkjet ink was prepared in the same manner as in Example 1 except that the amount was 3 parts by mass.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 65.0% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. The mass ratio B / C of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 1/2.
<Example 4>
The blending amount of the alicyclic epoxide (A) is 12.0 parts by mass, the blending amount of the epoxidized fatty acid glyceride (B) is 9.3 parts by mass, and the blending amount of the triazine ring-containing epoxide (C) is 18. An inkjet ink was prepared in the same manner as in Example 1 except that the amount was 7 parts by mass.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 70.0% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. The mass ratio B / C of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 1/2.
<Example 5>
The amount of the alicyclic epoxide (A) is 34.0 parts by mass, the amount of the epoxidized fatty acid glyceride (B) is 2.0 parts by mass, and the amount of the triazine ring-containing epoxide (C) is 4. An inkjet ink was prepared in the same manner as in Example 1 except that the amount was 0 parts by mass.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 15.0% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. The mass ratio B / C of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 1/2.
<Example 6>
The blending amount of the alicyclic epoxide (A) is 25.0 parts by mass, the blending amount of the epoxidized fatty acid glyceride (B) is 3.0 parts by mass, and the blending amount of the triazine ring-containing epoxide (C) is 12. An inkjet ink was prepared in the same manner as in Example 1 except that the amount was 0 parts by mass.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 37.5% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. Further, the mass ratio B / C = 1/4 of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 1/4.
<Example 7>
The blending amount of the alicyclic epoxide (A) is 31.0 parts by mass, the blending amount of the epoxidized fatty acid glyceride (B) is 6.0 parts by mass, and the blending amount of the triazine ring-containing epoxide (C) is 3. An inkjet ink was prepared in the same manner as in Example 1 except that the amount was 0 parts by mass.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 22.5% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. Further, the mass ratio B / C = 1 / 0.5 of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was obtained.
<Example 8>
The blending amount of the alicyclic epoxide (A) is 22.0 parts by mass, the blending amount of the epoxidized fatty acid glyceride (B) is 3.0 parts by mass, and the blending amount of the triazine ring-containing epoxide (C) is 15. An inkjet ink was prepared in the same manner as in Example 1 except that the amount was 0 parts by mass.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 45.0% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. Further, the mass ratio B / C = 1/5 of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C).
<Example 9>
The blending amount of the alicyclic epoxide (A) is 30.9 parts by weight, the blending amount of the epoxidized fatty acid glyceride (B) is 7.0 parts by weight, and the blending amount of the triazine ring-containing epoxide (C) is 2. An inkjet ink was prepared in the same manner as in Example 1 except that the amount was 1 part by mass.

The total blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was 22.8% by mass of the total amount of the three oxirane ring-containing compounds (A) to (C). It was. Further, the mass ratio B / C = 1 / 0.3 of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) was obtained.
<Comparative example 1>
The same amount as in Example 1 except that the blending amount of the alicyclic epoxide (A) was 40.0 parts by mass and the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) were not blended. Inkjet ink was prepared.

<Comparative example 2>
The blending amount of the alicyclic epoxide (A) was 35.0 parts by mass, the blending amount of the epoxidized fatty acid glyceride (B) was 5.0 parts by mass, and the triazine ring-containing epoxide (C) was not blended. Except for this, an inkjet ink was prepared in the same manner as in Example 1.
<Comparative Example 3>
The blending amount of the alicyclic epoxide (A) was 30.0 parts by mass, the blending amount of the triazine ring-containing epoxide (C) was 10.0 parts by mass, and the epoxidized fatty acid glyceride (B) was not blended. Except for this, an inkjet ink was prepared in the same manner as in Example 1.

<Comparative example 4>
10.0 parts by mass of 1,4-butanediol divinyl ether as a vinyl ether compound described in Patent Document 3 is blended with 30.0 parts by mass of the epoxidized fatty acid glyceride of (B), and the alicyclic epoxide of (A) An ink-jet ink was prepared in the same manner as in Example 1 except that the triazine ring-containing epoxide (C) was not blended.

<Curing property>
Using the inkjet ink of each Example and Comparative Example in an inkjet printer, solid printing was performed on the surface of a thin film aluminum for blister packs as a printing medium. Then, using a curing device [FireJet made by Phoseon Technology Co., Ltd.] using an ultraviolet LED, the solid print was cured by irradiating ultraviolet rays so that the total irradiation light amount was 150 mJ / cm ^2. The curability of the inkjet ink was evaluated.

◯: The solid print was not damaged even when rubbed with a finger, and the ink did not adhere to the finger. Good.
Δ: The solid print was damaged, but the ink did not adhere to the finger. Normal level.
X: The solid print was scratched and the ink adhered to the finger. Bad.
<Scratch resistance>
Using the ink jet inks of the examples and comparative examples in the same ink jet printer used in the curability evaluation, solid printing was performed on the surface of the same thin film aluminum for blister pack, and the total irradiation light amount was 300 mJ / cm ² . It was cured by irradiating with ultraviolet rays. Then, an iron ball having a diameter of 4 mm was reciprocated on the cured solid print in a state of being pressed with a load of 900 gf, and the scratch resistance of printing was evaluated according to the following criteria.

○: Solid printing did not peel even when the iron ball was reciprocated five times. Good.
(Triangle | delta): Although it did not peel until 3 reciprocations, it peeled locally along the locus | trajectory of an iron ball by 5 reciprocations. Normal level.
X: It peeled locally along the locus | trajectory of an iron ball by 3 reciprocations. Bad.
<Heat-resistant>
Using the ink jet inks of the examples and comparative examples in the same ink jet printer used in the curability evaluation, solid printing was performed on the surface of the same thin film aluminum for blister pack, and the total irradiation light amount was 300 mJ / cm ² . It was cured by irradiating with ultraviolet rays. Then, after heating to 250 ° C. for 0.5 seconds with the same thin film aluminum for blister pack overlaid on the solid printing, peel the thin film aluminum for blister pack, The heat resistance of printing was evaluated.

◯: No crack was observed in the solid printing, and there was no transfer of the solid printing to the thin film aluminum for the blister pack. Good.
Δ: Slight cracks were observed, but did not transfer to the stacked thin film aluminum for blister packs. Normal level.
X: Transferred to the laminated thin film aluminum for blister packs. Bad.

<Fixability>
Using the ink jet inks of the examples and comparative examples in the same ink jet printer used in the curability evaluation, solid printing was performed on the surface of the same thin film aluminum for blister pack, and the total irradiation light amount was 300 mJ / cm ² . It was cured by irradiating with ultraviolet rays. The fixability of printing was evaluated according to the following criteria.

○: The solid print was not peeled off even when the cellophane tape was applied on the solid print and then peeled off. Good.
(Triangle | delta): It peeled partially in a part of area | region which affixed the cellophane tape. Normal level.
X: Peeled on almost the entire surface where the cellophane tape was applied. Bad.
The above results are shown in Tables 1 to 3.

From the results of Comparative Example 1 in Table 3, when only the alicyclic epoxide (A) is used as the oxirane ring-containing compound together with the oxetane ring-containing compound, the curability is high but the cured product has flexibility. It was found that the scratch resistance of printing was poor due to shortage.
Further, from the result of Comparative Example 2, when two kinds of (A) alicyclic epoxide and (B) epoxidized fatty acid glyceride are used in combination as the oxirane ring-containing compound, flexibility and printing scratch resistance associated therewith are obtained. It was found that the heat resistance and fixability of the printing were poor, although the properties were improved.

Moreover, from the result of Comparative Example 3, when two types of (A) alicyclic epoxide and (C) triazine ring-containing epoxide are used in combination as the oxirane ring-containing compound, the flexibility of the cured product is insufficient. It was found that the scratch resistance of printing was poor.
From the results of Comparative Example 4, when only the alicyclic epoxide (A) is used as the oxirane ring-containing compound and the vinyl ether compound is used in combination, the curability, scratch resistance, heat resistance, and fixability are improved. Both were found to be defective.

On the other hand, from the results of Examples 1 to 9 in Table 1 and Table 2, by using together three types of (A) to (C) as the oxirane ring-containing compound together with the oxetane ring-containing compound, the curability is high, In addition, it was found that an ink-jet ink excellent in the flexibility of the cured product and the accompanying scratch resistance of printing, heat resistance and fixing property of the printing can be obtained.
From the results of Examples 1 to 5, in consideration of further improving the effect of the combined use, the blending ratio of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) is (A) It was found that the content is preferably 20% by mass or more and 65% by mass or less of the total amount of the three oxirane ring-containing compounds (C) to (C).

  Further, from the results of Examples 1 and 6 to 9, considering that the effect of the combined use is further improved, the mass ratio B of the epoxidized fatty acid glyceride (B) and the triazine ring-containing epoxide (C) It was found that / C = 1/4 to 1 / 0.5 is preferable.

Claims (4)

(A) alicyclic epoxide,
(B) Epoxidized fatty acid glyceride,
(C) three oxirane ring-containing compounds of a trivalent epoxide having a triazine ring as a skeleton,
An inkjet ink comprising: an oxetane ring-containing compound; and a polymerization initiator that initiates cationic polymerization of the oxirane ring-containing compound and the oxetane ring-containing compound by irradiation with active energy rays. 20 mass of the total amount of the three oxirane ring-containing compounds (A) to (C) in total of the epoxidized fatty acid glyceride (B) and the trivalent epoxide (C) having a triazine ring in the skeleton. 2. The inkjet ink according to claim 1, wherein the inkjet ink is contained in a proportion of not less than 65% and not more than 65 mass%.   The epoxidized fatty acid glyceride (B) and the trivalent epoxide having a triazine ring as a skeleton (C) in a ratio of mass ratio B / C = 1/4 to 1 / 0.5. 2. Ink jet ink according to 2. The trivalent epoxide having a triazine ring (C) as a skeleton has the formula (1):

[Wherein m, n and p are not 0, and m + n + p represents a number of 3 to 20. ]
The inkjet ink according to claim 1, wherein the inkjet ink is a compound represented by the formula: