JP2021080432A - Non-aqueous inkjet ink and printed matter of the same - Google Patents

Abstract

To provide a non-aqueous inkjet ink excellent in all of continuous discharge stability, brilliance of a printed matter and drying property.SOLUTION: The non-aqueous inkjet ink comprises an organic solvent (A), scaly metal particles (B) and a surface tension adjusting additive (C), in which the organic solvent (A) contains an alkylene glycol monoalkyl ether-based solvent (a1-1) represented by general formula 1 by 10 to 75 mass% with respect to the whole amount of the organic solvent (A); the scaly metal particles (B) are scaly particles having an average thickness (t) of 1 to 50 nm; and the content of the scaly metal particles (B) is 0.1 to 5 mass% with respect to the whole amount of the non-aqueous inkjet ink.SELECTED DRAWING: None

Description

The present invention relates to a non-aqueous inkjet ink and a printed matter thereof.

The inkjet recording method is a recording method in which ink droplets are ejected from a nozzle of an inkjet print head onto a recording medium to obtain a printed matter on which characters and images are recorded. According to this method, not only the noise of the equipment used is low and the operability is good, but also the colorization is easy and various kinds of recording media can be used. Therefore, the office has an advantage. It is used as a digital printing output device not only in households and households but also in industrial applications. In fact, non-aqueous inkjet printing machines capable of printing on substrates such as vinyl chloride and PET are commercially available and are used in various applications including indoor and outdoor advertising applications.

On the other hand, there is an increasing demand for decorating recording media by performing high-definition printing using an inkjet recording method. Then, as one of the decorations, studies on the production of printed matter having brilliance are being actively conducted. Conventionally, in order to produce a printed matter having brilliance, it has been necessary to use a recording medium on which a metal layer is vapor-deposited in advance, or to perform post-processing by foil stamping or thermal transfer. However, when using a special recording medium or producing printed matter by post-processing, it is necessary to install a special device in the printing machine, select a base material because a special glue is used, and form delicate patterns and small letters. It was difficult, and the load on the versatility of the base material, production, and cost was large. In particular, the above-mentioned post-processing method has a drawback that the foil is applied to a size larger than the required pattern and the required pattern is die-cut, and there is a large loss of metal foil and the like, which is costly.

On the other hand, the production of brilliant printed matter using the inkjet recording method is useful from the viewpoint of versatility of the base material and cost reduction, and has attracted a great deal of attention. And so far, various non-aqueous inkjet inks (hereinafter, also simply referred to as "inkjet inks" and "inks") capable of producing bright printed matter have been proposed.

For example, Patent Document 1 discloses a non-aqueous inkjet ink composition (non-aqueous inkjet ink) containing a bright pigment, a glycol diether having a flash point of 70 ° C. or lower, and a glycol monoether. .. According to Patent Document 1, by using the glycol diether and the glycol monoether (however, the terminal alkyl group has 1 to 4 carbon atoms), the dryness of the ink is adjusted, and at the same time, the aggregation unevenness is uneven. Is also said to be able to be suppressed. However, under the condition of 40 to 60 ° C., which is the drying condition of a normal non-aqueous inkjet ink, a solvent having a flash point of 70 ° C. or lower dries in a short time. Convection occurs, and the brilliant pigment cannot be arranged substantially parallel to the surface of the recording medium, leading to a decrease in brilliance. In addition, due to the high drying property of glycol diether having a flash point of 70 ° C. or lower, the drying property at the nozzle portion of the inkjet print head cannot be controlled, which may adversely affect the continuous ejection property.

Further, Patent Document 2 discloses an ink composition (inkjet ink) containing a metallic pigment, an alkylene glycol diether and a lactone. For example, in an example, by printing on a photo paper having an ink receiving layer, the ink composition is disclosed. An image having a metallic luster such as a mirror luster is formed. However, when the present inventors reproduced and evaluated the ink composition described in the above Examples, it was not possible to obtain a printed matter having a high metallic luster on a recording medium without an ink receiving layer. It was. In addition, a recording medium having an ink receiving layer is often printed without heating, and when an ink composition containing a large amount of lactone having a high boiling point is printed on a recording medium without an ink receiving layer, the lactone is immediately produced. There was also a problem that the ink did not volatilize and remained on the printed matter, and it took a long time to dry.

Further, Patent Document 3 discloses an ink composition containing a metal pigment, an organic solvent, and a silicone oil having a kinematic viscosity of 2 to 30 cSt. The ink composition improves the glossiness of a printed matter and is used on a recording medium. It is stated that the prevention of bleeding can be realized. Further, in paragraphs 0062 to 0063 of Patent Document 3, as the organic solvent, 60 to 80% by mass of diethylene glycol diethyl ether and less than 1% by mass of tetraethylene glycol monobutyl ether in the total amount of the ink composition are described. And 24 to 37% by weight of γ-butyrolactone and / or tetraethylene glycol dimethyl ether have been shown to be suitable. However, since both γ-butyrolactone and tetraethylene glycol dimethyl ether have a high boiling point, for example, when an ink composition having the above structure is printed on a recording medium without an ink receiving layer, the drying property is easily deteriorated significantly. I can imagine. On the other hand, in the examples of Patent Document 3, tetraethylene glycol monomethyl ether having a boiling point of 164 ° C. under 1 atm is used instead of tetraethylene glycol dimethyl ether. However, in this case, on the contrary, the drying property becomes too high, so that there is a high possibility that the continuous ejection stability and the brilliance of the printed matter deteriorate as in the case of Patent Document 1 described above.

Patent Document 4 contains an organic solvent (for example, propylene glycol) having a boiling point of 150 ° C. or higher and a solubility parameter of 24 MPa ^1/2 or higher, and has a maximum absorption wavelength of 800 nm to 2500 nm in the wavelength range of 300 nm to 2500 nm. Inkjet inks present in the wavelength range are disclosed. According to Patent Document 4, it is possible to form an image (neutral metallic image) having mirror gloss and suppressed color. However, when an organic solvent having a solubility parameter of 24 MPa ^1/2 or more is used, the resin in the ink is limited, and it becomes difficult to control the ejection property and the high brightness of the printed matter. In the first place, the ink specifically disclosed in the examples of Patent Document 4 is a water-based inkjet ink containing water as a main component, and its technical features are significantly different from those of the non-water-based inkjet ink to which the present invention belongs.

As described above, a non-aqueous inkjet ink having excellent continuous ejection stability, brilliance of printed matter, and drying property has never existed.

Japanese Unexamined Patent Publication No. 2016-150984 Japanese Unexamined Patent Publication No. 2013-237850 Japanese Unexamined Patent Publication No. 2012-017436 International Publication No. 2017/149918

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a non-aqueous inkjet ink having excellent continuous ejection stability, brilliance of printed matter, and drying property.

As a result of diligent studies by the present inventors in order to solve the above problems, they have found that the above problems can be solved by a non-aqueous inkjet ink having the following configuration, and have completed the present invention.

That is, the present invention is a non-aqueous inkjet ink containing an organic solvent (A), scaly metal particles (B), and an additive (C) for adjusting surface tension, and the organic solvent (A) is a non-aqueous inkjet ink. The alkylene glycol monoalkyl ether solvent (a1-1) represented by the following general formula 1 is contained in an amount of 10 to 75% by mass based on the total amount of the organic solvent (A), and the scaly metal particles (B) are averaged. Non-aqueous particles having a thickness (t) of 1 to 50 nm, and the content of the scaly metal particles (B) is 0.1 to 5% by mass based on the total amount of the non-aqueous inkjet ink. Regarding inkjet ink.

R1- (O-R2) _n1- OH [General formula 1]

In the above general formula 1, R1 represents a hydrocarbon group having 6 to 12 carbon atoms, R2 represents an alkylene group having 2 or 3 carbon atoms, and n1 represents 1 or 2.

The present invention also relates to the non-aqueous inkjet ink, wherein the scaly metal particles (B) contain at least one selected from the group consisting of Al, In, and Cu as metal elements.

The present invention also relates to the non-aqueous inkjet ink, wherein the organic solvent (A) further contains an alkylene glycol dialkyl ether solvent (a2) and / or an alkylene glycol monoalkyl ether monoacetate solvent (a3). ..

Further, in the present invention, the organic solvent (A) further contains an alkylene glycol monoalkyl ether solvent (a1-2) represented by the following general formula 2, and the alkylene glycol monoalkyl ether solvent (a1-1). ), The ratio of the blending amount of the alkylene glycol monoalkyl ether solvent (a1-2) to the blending amount of 10 to 500% by mass is related to the non-aqueous inkjet ink.

R3- (O-R4) _n2- OH [General formula 2]

In the general formula 2, R3 represents a hydrocarbon group having 1 to 5 carbon atoms, R4 represents an alkylene group having 2 to 6 carbon atoms, and n2 represents an integer of 1 to 4 carbon atoms.

The present invention also relates to the non-aqueous inkjet ink, wherein the surface tension adjusting additive (C) contains a surface tension adjusting additive having a polysiloxane chain structure.

The present invention also relates to the non-aqueous inkjet ink for printing on a base material selected from a plastic base material, a paper base material, a metal base material, and a glass base material.

The present invention also relates to a printed matter in which the non-aqueous inkjet ink composition is printed on a recording medium.

INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to provide a non-aqueous inkjet ink having excellent continuous ejection stability, brilliance of printed matter, and drying property.

Hereinafter, the present invention will be described in detail. The embodiments described below describe an example of the present invention. The present invention is not limited to the following embodiments, and includes modifications that are carried out without changing the gist of the present invention.

As described in the background art, a non-aqueous inkjet ink containing scaly metal particles is used in order to obtain a printed matter having brilliance. In the print layer formed by using the non-aqueous inkjet ink, the scaly metal particles are arranged substantially parallel to the surface of the recording medium and reflect the light incident on the print layer. Then, the brilliance is expressed. However, depending on the type and amount of the components constituting the non-aqueous inkjet ink or the printing conditions, the non-aqueous inkjet ink dries or thickens before the arrangement of the metal particles, resulting in a printed matter having poor brilliance. There is a possibility that it will end up.

As a countermeasure against the above problem, for example, by increasing the amount of metal particles in the non-aqueous inkjet ink, it is conceivable to increase the absolute amount of the metal particles arranged parallel to the surface of the recording medium. However, an increase in the amount of metal particles as a solid component may lead to deterioration of the continuous ejection stability of the non-aqueous inkjet ink. In addition, for example, by adding a high boiling point solvent or lowering the drying temperature, the time from applying the non-aqueous inkjet ink to the recording medium to drying is extended, and the time until the metal particles are arranged is increased. The measure is also conceivable. However, if the drying property is insufficient in inkjet printing, for example, when the recording medium after printing is wound up, a part of the print layer adheres to the back surface of the recording medium, or the printed matter is inferior in scratch resistance. There is a high possibility that problems such as becoming will occur.

Therefore, as a result of diligent studies by the present inventors in order to solve the above problem, the alkylene glycol monoalkyl ether solvent (a1-1) represented by the above general formula 1 (hereinafter, simply "solvent (a1-1)"). ) ”) Is blended in a certain amount to specify the thickness and blending amount of the scaly metal particles, and by using the surface tension adjusting additive (C), continuous ejection stability and brilliance of printed matter are obtained. It has been found that a non-aqueous inkjet ink having excellent properties and drying properties can be obtained. Although it is inference, the mechanism is explained below.

First, the non-aqueous inkjet ink of the present invention contains scaly metal particles (B) having an average thickness (t) of 1 to 50 nm in an amount of 0.1 to 5% by mass based on the total amount of the non-aqueous inkjet ink. By using the scaly metal particles (B) having an average thickness within the above range, the step in the portion where the scaly metal particles (B) overlap each other in the printing layer is reduced, and a more uniform arrangement is realized. it can. Further, it is generally known that scaly particles have a strong interaction between particles due to their proximity to each other and are likely to aggregate with each other. Especially in the case of inkjet ink, if particle agglutination occurs in the inkjet head, the continuous ejection stability may deteriorate. Therefore, in the present invention, the blending amount of the scaly metal particles (B) is kept within the above range, and the proximity of the particles is suppressed, thereby suppressing the deterioration of the continuous discharge stability.

Further, in the present invention, the alkylene glycol monoalkyl ether solvent (a1-1) represented by the general formula 1 is contained in an amount of 10 to 75% by mass based on the total amount of the organic solvent (A). These solvents (a1-1) have a highly hydrophobic group (group represented by R1) and a highly hydrophilic group (group represented by O-R2) in one molecule. Microscopically, it is considered to function as a surfactant. On the other hand, these solvents also have a function as a high boiling point solvent.

As a result, while the non-aqueous inkjet ink of the present invention is present in the inkjet head, the solvent (a1-1) suppresses the proximity of the scaly metal particles (B) to each other and dries on the nozzle surface. It is considered that this is prevented and contributes to further improvement of continuous discharge stability. Further, when the inkjet ink is applied to the recording medium, it volatilizes in the same manner as the other organic solvent (A) without interfering with the arrangement of the scaly metal particles (B), and thus has excellent brilliance. Printed matter is expected to be obtained.

However, as described above, since the solvent (a1-1) has a function as a high boiling point solvent, it is less likely to volatilize than other organic solvents (A) and may adversely affect the drying property of the inkjet ink. .. Therefore, in the non-aqueous inkjet ink of the present invention, the surface tension adjusting additive (C) is further blended to wet and spread the droplets of the non-aqueous inkjet ink applied on the recording medium, thereby causing the solvent (a1). -1) promotes rapid volatilization. Further, it is considered that the non-uniformity of the arrangement of the scaly metal particles (B) is suppressed by the droplets getting wet and spreading and the height thereof becoming smaller, which leads to the improvement of the brilliance of the printed matter.

As described above, it can be said that the configuration of the present invention is indispensable in order to obtain a non-aqueous inkjet ink excellent in all of continuous ejection stability, brilliance of printed matter, and drying property.

Subsequently, each component constituting the non-aqueous inkjet ink of the present invention will be described in detail with reference to preferred forms.

[Organic solvent (A)]
[Alkylene glycol monoalkyl ether solvent (a1-1)]
As described above, the non-aqueous inkjet ink of the present invention contains the alkylene glycol monoalkyl ether solvent (a1-1) represented by the following general formula 1 as the organic solvent (A).

R1- (O-R2) _n1- OH [General formula 1]

In the general formula 1, R1 represents a hydrocarbon group having 6 to 12 carbon atoms, which may be linear or branched, and may form a ring containing an aromatic ring. The R1 is preferably 6 to 10 from the viewpoint of keeping the viscosity and boiling point of the solvent (a1-1) within a suitable range and achieving both continuous ejection stability and brilliance of printed matter, and 6 to 8 Is particularly preferable.
Further, R2 represents an alkylene group having 2 or 3 carbon atoms, and may be linear or branched. The R2 is an alkylene group (ethylene group) having 2 carbon atoms from the viewpoint of enhancing the function of the solvent (a1-1) as a surfactant and improving both the continuous ejection stability and the brilliance of the printed matter. Is preferable.
Further, n1 represents 1 or 2, and is preferably 1 from the viewpoint of dryness of the printed matter.

Examples of the alkylene glycol monoalkyl ether-based solvent (a1-1) represented by the general formula 1 include ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol monoheptyl ether, diethylene glycol monoheptyl ether, and ethylene glycol monooctyl ether. Diethylene glycol monooctyl ether, ethylene glycol monoethylhexyl ether, diethylene glycol monoethylhexyl ether, ethylene glycol monononyl ether, diethylene glycol monononyl ether, ethylene glycol monodecyl ether, diethylene glycol monodecyl ether, ethylene glycol monoundecyl ether, diethylene glycol monoundecyl ether , Ethylene glycol monomethyldecyl ether, diethylene glycol monomethyldecyl ether, ethylene glycol monododecyl ether, diethylene glycol monododecyl ether, etc. (di) ethylene glycol monoaliphatic alkyl ethers;
Dipropylene glycol monohexyl ether, dipropylene glycol monohexyl ether, propylene glycol monoheptyl ether, dipropylene glycol monoheptyl ether, propylene glycol monooctyl ether, dipropylene glycol monooctyl ether, propylene glycol monoethylhexyl ether, dipropylene glycol monoethylhexyl Ether, propylene glycol monononyl ether, dipropylene glycol monononyl ether, propylene glycol monodecyl ether, dipropylene glycol monodecyl ether, propylene glycol monoundecyl ether, dipropylene glycol monoundecyl ether, propylene glycol monomethyldecyl ether, di (Di) propylene glycol monoalkyl ethers such as propylene glycol monomethyldecyl ether, propylene glycol monododecyl ether, dipropylene glycol monododecyl ether;
(Di) ethylene glycol monoaromatic ethers such as ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monobenzyl ether, ethylene glycol monophenethyl ether, diethylene glycol monophenyl ether, etc.;
(Di) propylene glycol monoaromatic ethers such as propylene glycol monophenyl ether, dipropylene glycol monophenyl ether, propylene glycol monobenzyl ether, dipropylene glycol monobenzyl ether, propylene glycol monophenethyl ether, dipropylene glycol monophenyl ether, etc. Kind;
Etc., and one or a combination of two or more of these can be used. Among them, in general formula 1, R1 is a hydrocarbon group having 6 to 8 carbon atoms and R2 is an alkylene group having 2 carbon atoms in terms of continuous print stability, brilliance of printed matter, and dryness. A compound in which n is 1, specifically, ethylene glycol monohexyl ether, ethylene glycol monooctyl ether, ethylene glycol monoethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, ethylene glycol monophenethyl ether. It is preferable to use one or more selected from the group consisting of, and it is more preferable to use one or more selected from the group consisting of ethylene glycol monoethylhexyl ether, ethylene glycol monophenyl ether, and ethylene glycol monobenzyl ether. It is preferable to use ethylene glycol monophenyl ether, and it is particularly preferable to use it.

The content of the alkylene glycol monoalkyl ether solvent (a1-1) is in the total amount of the organic solvent (A) from the viewpoint of obtaining a non-aqueous inkjet ink having excellent continuous ejection stability, brilliance of printed matter, and drying property. It is 10 to 75% by mass, preferably 10 to 65% by mass, and particularly preferably 15 to 55% by mass.

From the same viewpoint as above, the content of the alkylene glycol monoalkyl ether solvent (a1-1) is preferably 9 to 74% by mass, preferably 9 to 64% by mass, based on the total amount of the non-aqueous inkjet ink. % Is more preferable, and 14 to 54% by mass is particularly preferable.

[Alkylene glycol monoalkyl ether solvent (a1-2)]
In the non-aqueous inkjet ink of the present invention, as the organic solvent (A), an alkylene glycol monoalkyl ether solvent other than the solvent (a1-1) described above (hereinafter, "alkylene glycol monoalkyl ether solvent (a1)" is used in the present specification. -2) ”. Alternatively, a simple“ solvent (a1-1) ”) may be used. Specifically, as the alkylene glycol monoalkyl ether solvent (a1-2), an alkylene glycol monoalkyl ether solvent represented by the following general formula 2 can be used.

R3- (O-R4) _n2- OH [General formula 2]

In the general formula 2, R3 represents a hydrocarbon group having 1 to 5 carbon atoms, and may be linear or branched. The R3 is an alkyl group having 1 or 2 carbon atoms from the viewpoint that the viscosity and boiling point of the non-aqueous inkjet ink can be kept within a suitable range and the non-aqueous inkjet ink having excellent continuous ejection stability can be obtained. Is preferable.
Further, R4 represents an alkylene group having 2 to 6 carbon atoms, and may be linear or branched. From the same viewpoint as in the case of R3, the R4 is more preferably an alkylene group having 2 to 5 carbon atoms, and further preferably an alkylene group having 3 or 4 carbon atoms.
Further, n2 represents an integer of 1 to 4, and is preferably 1 or 2.

Examples of the alkylene glycol monoalkyl ether-based solvent (a1-2) represented by the general formula 2 include ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monopentyl ether, and propylene glycol monomethyl ether (. 1-methoxy-2-propanol), propylene glycol monobutyl ether, propylene glycol n-propyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monopentyl ether, dipropylene glycol monomethyl ether, Dipropylene glycol monoethyl ether, dipropylene glycol n-propyl ether, dipropylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono Butyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monobutyl ether, 3-methoxy-3-methyl-1-butanol, 3-methoxybutanol and the like can be mentioned, and one or more of these can be used in combination. Among them, 1-methoxy-2-propanol, dipropylene glycol monomethyl ether, 3-methoxy-3-methyl- from the viewpoint of obtaining non-aqueous inkjet ink having excellent continuous ejection stability and drying property and odor. It is preferable to contain one or more selected from 1-butanol and 3-methoxybutanol, and in particular, it is extremely preferable to contain 3-methoxybutanol from the viewpoint of solubility of the binder resin described later.

Further, from the viewpoint of improving the drying property of the non-aqueous inkjet ink, 50% by mass or more of the total amount of the alkylene glycol monoalkyl ether solvent (a1-2) has a boiling point of 165 ° C. or less under 1 atm. More preferably, it is an alkyl ether solvent (a1-2'). As the alkylene glycol monoalkyl ether solvent (a1-2') having a boiling point of 165 ° C. or lower under 1 atm, 1-methoxy-2-propanol (boiling point 121 ° C.) and / or 3-methoxybutanol (boiling point). 158 ° C.) is preferably contained.

When the alkylene glycol monoalkyl ether solvent (a1-2) represented by the general formula 2 is used, the blending amount thereof is from the viewpoint that a non-aqueous inkjet ink having excellent continuous ejection stability and drying property can be obtained. The total amount of the organic solvent (A) is preferably 5 to 70% by mass, more preferably 5 to 50% by mass.

Further, the blending amount of the alkylene glycol monoalkyl ether solvent (a1-2) with respect to the blending amount of the solvent (a1-1) is 10 to 500% by mass from the viewpoint of preferably exhibiting the effects of the present invention. Is preferable, and it is more preferably 25 to 250% by mass.

[Alkylene glycol dialkyl ether solvent (a2)]
[Alkylene glycol monoalkyl ether monoacetate solvent (a3)]
Further, in the present invention, the organic solvent (A) is an alkylene glycol dialkyl ether solvent (a2) represented by the following general formula 3 and / or an alkylene glycol monoalkyl ether monoacetate represented by the following general formula 4. It is preferable to contain the system solvent (a3). By containing these solvents, the surface tension during discharge and drying can be controlled, and further image quality can be achieved. In addition, these solvents are preferably used because they have high compatibility with the solvent (a1-1), and as a result, the effects of the solvent (a1-1) described above can be suitably exhibited.

R5- (O-R6) _m- OR7 [General formula 3]

In the general formula 3, R5 and R7 independently represent an alkyl group having 1 to 4 carbon atoms, which may be linear or branched, and are an alkyl group having 1 or 2 carbon atoms. Is preferable.
Further, R6 represents an alkylene group having 2 to 4 carbon atoms, which may be linear or branched, and is more preferably an alkylene group having 2 or 3 carbon atoms.
Further, m represents an integer of 1 to 4, and is more preferably 1 or 2.

Examples of the alkylene glycol dialkyl ether-based solvent (a2) represented by the general formula 3 include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, and triethylene glycol dimethyl ether. , Triethylene glycol diethyl ether, triethylene glycol methyl butyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, tripropylene glycol dimethyl ether and the like, and one of them or Two or more types can be used in combination. Among them, it is selected from diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, and dipropylene glycol dimethyl ether from the viewpoint of storage stability and drying property of non-aqueous inkjet ink and compatibility with solvent (a1-1). It is preferable to use one or more.

R8-CO- (O-R9) _l- OR10 [General formula 4]

In the general formula 4, R8 represents an alkyl group having 1 to 6 carbon atoms, which may be linear or branched, and is preferably an alkyl group having 1 or 2 carbon atoms.
R10 represents an alkyl group having 1 to 6 carbon atoms, which may be linear or branched, preferably an alkyl group having 1 to 4 carbon atoms, and an alkyl group having 1 to 2 carbon atoms. Is more preferable.
R9 represents an alkylene group having 2 to 6 carbon atoms, which may be linear or branched, and is preferably an alkylene group having 2 to 4 carbon atoms.
l represents an integer of 1 to 6, preferably 1 to 4, more preferably 1 or 2.

Examples of the alkylene glycol monoalkyl ether monoacetate solvent (a3) represented by the general formula 4 include (poly) ethylene glycol monoalkyl ether acetates, (poly) propylene glycol monoalkyl ether acetates, and (poly). Butylene glycol monoalkyl ether acetates and the like can be mentioned. Specifically, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl. Ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol dibutyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3 − Ethoxypropionate, propylene glycol monomethyl ether propionate and the like. In the present invention, one or more of these can be used in combination. Among them, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, 3-methoxybutyl It is preferable that 3-methoxybutyl acetate contains at least one selected from acetate from the viewpoint of drying property at the time of printing and compatibility with the solvent (a1-1).

When the alkylene glycol dialkyl ether solvent (a2) represented by the general formula 3 and / or the alkylene glycol monoalkyl ether monoacetate solvent (a3) represented by the general formula 4 is used, a binder described later will be used. From the viewpoint of the solubility of the resin and the brilliance of the printed matter, the total amount of the compound is preferably 10 to 70% by mass based on the total amount of the organic solvent (A), and more preferably 20 to 40% by mass. preferable.

[Other solvents]
In the present invention, other solvents may be used in combination for the purpose of adjusting the viscosity, surface tension, boiling point, etc. of the non-aqueous inkjet ink to obtain the non-aqueous inkjet ink having excellent continuous ejection stability and drying property. it can. Examples of the other solvent include acetic acid ester, lactic acid ester, alkoxyalkylamide, alkanediol, cyclic ether, heterocyclic solvent, hydrocarbon solvent and the like. Specifically, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, N, N-dimethyl-β-butoxypropionamide, N, N-dibutyl-β-butoxypropionamide, ethylene glycol, Diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, dipropylene glycol, polypropylene glycol, 1,2-butanediol, 1,3-butanediol, 1, 4-butanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 2-methyl-2, 4-Pentanediol, 3-methyl-2-oxazolidinone, 2-pyrrolidone (γ-butyrolactam), 1-methyl-2-pyrrolidone, ε-caprolactam, γ-butyrolactone, γ-valerolactone, ε-caprolactone, propylene carbonate, etc. Can be mentioned. Above all, from the viewpoint of continuous discharge stability and dryness, it is preferable to use one having a boiling point of less than 195 ° C. under 1 atm.

On the other hand, in the present invention, it is preferable to limit the blending amount of the heterocyclic solvent among the other solvents exemplified above. In general, a heterocyclic solvent has high substrate permeability and resin solubility, and in the present invention, the dispersed state of the scaly metal particles (B) described later is deteriorated, and the scaly metal particles (B) are described. May inhibit the sequence. Therefore, in the present invention, from the viewpoint of obtaining a non-aqueous inkjet ink having excellent continuous ejection stability and drying property, the blending amount of the heterocyclic solvent is 10% by mass or less with respect to the total amount of the non-aqueous inkjet ink. It is preferably 5% by mass or less, and particularly preferably 3% by mass or less.

[Scale metal particles (B)]
As the scaly metal particles (B) used in the non-aqueous inkjet ink of the present invention, conventionally known scaly metal particles having an average thickness (t) of 1 to 50 nm can be arbitrarily used. In the present invention, the term "scaly" means that the ratio of the average particle size (D50) to the average thickness (t), which will be described later, is D50 / t = 5 or more.

As described above, in the present invention, by setting the average thickness (t) of the scaly metal particles (B) to 1 to 50 nm, it is possible to obtain a printed matter having high brilliance. That is, when the average thickness (t) is 1 nm or more, the recording medium is sufficiently concealed by the scaly metal particles (B), and the incident light on the printed matter is not transmitted. Further, by setting the average thickness (t) to 50 nm or less, the step of the portion where the scaly metal particles (B) overlap each other becomes small, the surface of the printed matter is smoothed, and the scaly metal particles (B) are smoothed. Since diffused reflection of incident light does not occur at the edge portion of), a printed matter having excellent brilliance can be obtained.

The average thickness (t) of the scaly metal particles (B) is 5 to 40 nm from the viewpoint of further enhancing the brilliance of the printed matter, improving the continuous ejection stability, and reducing the manufacturing cost. It is preferably 10 to 30 nm, more preferably 10 to 25 nm. The average thickness (t) can be measured by, for example, a scanning electron microscope. Specifically, the scaly metal particles (B) and acetone are mixed to prepare a dilute dispersion of the scaly metal particles (B), and then the dilute dispersion is air-dried on a glass plate. Then, the glass plate is observed from the side using a scanning electron microscope, the thicknesses of 30 randomly selected scaly metal particles (B) are measured, and then the average value is calculated. It can be the average thickness (t) in the present invention.

Further, as described above, the average particle size (D50) of the scaly metal particles (B) in the present invention is 5 times or more the average thickness (t), but the average particle size (D50) is 0.1 to 2 μm. Is preferable. By setting the average particle size (D50) to 0.1 μm or more, the recording medium can be sufficiently concealed and the surface of the print layer is smoothed, so that the printed matter has excellent brilliance. Further, by setting the average particle size (D50) to 2 μm or less and further combining it with a solvent (a1-1), an ink having both continuous ejection stability and brilliance of printed matter can be obtained.

From the viewpoint of improving both the continuous ejection stability and the brilliance of the printed matter, the average particle size (D50) is more preferably 0.1 to 1.5 μm, more preferably 0.15 to 1.0 μm. It is more preferably 0.2 to 0.8 μm, and most preferably 0.2 to 0.8 μm. The average particle size (D50) can be measured using, for example, a laser diffraction type particle size distribution measuring device (Microtrac MT3300EXII, particle permeability: reflection, calculation mode: MT3000II) manufactured by Nikkiso Co., Ltd.

The "metal particles" in the present invention refer to pigments mainly containing single metal materials and alloy materials (50% by mass or more). Specific examples of the material include single metal materials such as Al, In, Sn, Cu, Zn, Si, Fe, and Ag, and alloy materials such as brass, bronze, and stainless steel. Further, the surface may be treated with an inorganic substance (metal oxide, mica, glass, etc.), an organic substance (color pigment, surfactant, resin, etc.), a silane coupling agent, or the like, or a laminate containing a metal layer. May be used as the scaly metal particles (B). Further, two or more kinds of scaly metal particles (B) can be used in combination.

In the present invention, from the viewpoint of obtaining a printed matter having excellent brilliance, scaly metal particles (B) containing at least one selected from the group consisting of Al, In, and Cu are used as metal elements. It is preferable, and it is more preferable to use the scaly metal particles (B) containing Al and / or In from the viewpoints of continuous ejection stability, brilliance of printed matter, and manufacturing cost.

The scaly metal particles (B) of the present invention may be produced by any method as long as they have the above average thickness (t), but have a more uniform average thickness (t). From the viewpoint of obtaining scaly metal particles (B) and producing a printed matter having excellent brilliance, it is more preferable that the scaly metal particles (B) are produced by crushing a metal vapor deposition film.

The content of the scaly metal particles (B) in the non-aqueous inkjet ink of the present invention is 0.1 based on the total amount of the non-aqueous inkjet ink from the viewpoint of achieving both continuous ejection stability and brilliance of printed matter. ~ 5% by mass. The content is more preferably 0.2 to 4% by mass, further preferably 0.3 to 3% by mass, and most preferably 0.4 to 2.5% by mass.

[Colorant]
The non-aqueous inkjet ink of the present invention may contain a colorant. For example, when silver-white scaly metal particles such as Al particles are used as the scaly metal particles (B), excellent brilliance can be achieved by using the scaly metal particles (B) and a colored colorant in combination. Colored printed matter having a property (for example, gold (metallic yellow) color, metallic blue color, metallic red color, metallic black color) can be obtained.

As the colorant, dyes and / or pigments generally used for inkjet inks can be used. Further, as the pigment, an organic pigment and / or an inorganic pigment can be arbitrarily selected. As the inorganic pigment, for example, carbon black, iron oxide, titanium oxide, zirconium oxide, aluminum oxide, calcium carbonate, etc. can be used.

Further, exemplifying the organic pigment by a color index (CI) number, C.I. I. Pigment Yellow 12, 13, 14, 15, 16, 17, 20, 24, 55, 74, 83, 86, 87, 93, 109, 110, 117, 120, 125, 124, 128, 129, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 170, 171, 172, 174, 176, 180, 185, 188, C.I. I. Pigment Orange 16, 36, 43, 51, 55, 59, 61, 64, C.I. I. Pigment Red 9, 48, 49, 52, 53, 57, 97, 122, 123, 146, 149, 150, 168, 177, 180, 185, 192, 202, 206, 207, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 245, 269, C.I. I. Pigment Violet 19, 23, 29, 30, 37, 40, 50, C.I. I. Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 22, 60, 64, C.I. I. Pigment Green 7, 36, C.I. I. Pigment Brown 23, 25, 26, C.I. I. Pigment Black 1 and the like.

These colorants can be used within a range that does not impair the brilliance of the printed matter. Further, considering the storage stability and continuous ejection stability of the non-aqueous inkjet ink, the suitable blending amount of the colorant is 10% by mass or less and 5% by mass or less with respect to the total amount of the non-aqueous inkjet ink. Is more preferable, and 3% by mass or less is most preferable.

The average particle size of the pigment used as the colorant is preferably 50 to 350 nm. When the average particle size of the pigment is 50 nm or more, light resistance and coloring power are obtained, and when it is 350 nm or less, the storage stability and continuous ejection stability of the non-aqueous inkjet ink are good. The average particle size of the pigment is a volume-based median size. For example, a non-aqueous inkjet ink produced excluding scaly metal particles (B) is diluted 200 to 1000 times with ethyl acetate, and Nikki Sosha Co., Ltd. It can be measured using a dynamic light scattering type particle size distribution measuring device (Microtrac UPA150).

[Pigment Dispersant]
As one embodiment of the present invention, a pigment dispersant is used in order to improve the dispersibility of the scaly metal particles (B) and the colorant, and to improve the brilliance of the printed matter and the storage stability of the non-aqueous inkjet ink. It is possible. Conventionally known compounds can be used as the pigment dispersant, but a resin type having a basic functional group is used from the viewpoints of continuous ejection stability, brilliance of printed matter, and storage stability of non-aqueous inkjet ink. It is preferable to use a dispersant.

Commercially available pigment dispersants that can be suitably used in the present invention include Solspers 32000, 76400, 76500, J200, and J180 manufactured by Lubrizol; Disperbyk-161, 162, 163, 164, 165, 166 manufactured by Big Chemie. , 167, 168, etc .; Examples thereof include Ajinomoto Fine-Techno's Ajisper PB821, PB822 and the like. The content of the pigment dispersant is preferably 5% by mass or less, more preferably 3% by mass or less, based on the total amount of the non-aqueous inkjet ink. When the content of the pigment dispersion is 5% by mass or less, the whitening phenomenon of the printed matter is suppressed and the printed matter having excellent brilliance can be obtained, which is preferable.

The weight average molecular weight (hereinafter referred to as Mw) of the pigment dispersant is preferably 5,000 to 50,000, and more preferably 10,000 to 45,000. When Mw is 5,000 or more, the pigment dispersant can stably exist in the organic solvent (A) used for the non-aqueous inkjet ink, so that the scaly metal particles (B) and the colorant also aggregate. As a result, a non-aqueous inkjet ink having excellent continuous ejection stability and brilliance of printed matter is obtained. Further, when it is 50,000 or less, the compatibility with the binder resin described later becomes good, the whitening phenomenon of the printed matter is suppressed, and the printed matter having excellent brilliance can be obtained.

Further, the pigment dispersant preferably has a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) of Mw / Mn of 2 or less, and more preferably 1.8 or less. When Mw / Mn is 2 or less, the variation in the average particle diameters of the scaly metal particles (B) and the colorant becomes small, the non-aqueous inkjet ink has both low viscosity and storage stability, and continuous ejection. It is possible to improve the stability and the brilliance of the printed matter.

Here, Mw and Mn can be determined as polystyrene-equivalent molecular weights by general gel permeation chromatography (hereinafter referred to as GPC). In the present invention, it is a polystyrene-equivalent molecular weight when DMF is used as a developing solvent in a GPC (manufactured by Tosoh Co., Ltd., HLC-8320 GPC) equipped with an RI detector using a TSKgel column (manufactured by Tosoh Co., Ltd.).

The acid value of the pigment dispersant is preferably 5 to 20 (mgKOH / g), more preferably 5 to 15 (mgKOH / g). The amine value of the pigment dispersant is preferably 5 to 50 (mgKOH / g), more preferably 20 to 50 (mgKOH / g), and more preferably 25 to 40 (mgKOH / g). More preferred. When the acid value and amine value of the pigment dispersant are within the above ranges, the storage stability of the non-aqueous inkjet ink becomes good. Further, when the dispersion treatment is applied to the scaly metal particles (B) and / or the mixture of the colorant and the pigment dispersant, the time until the dispersion treatment is completed is shortened.

The "acid value" in the present specification represents the number of mg of potassium hydroxide required to neutralize the acid group present in 1 g of the dispersant solid content. The acid value can be measured by the potentiometric titration method according to JIS K 0070. Further, the "amine value" represents the number of mg (total amine value) of potassium hydroxide which is equivalent to hydrochloric acid required to neutralize the amine present in 1 g of the dispersant solid content. The amine value can be calculated by converting the value measured by the potentiometric titration method using a 0.1 N hydrochloric acid aqueous solution into the equivalent of potassium hydroxide.

[Additive for adjusting surface tension (C)]
As described above, in the present invention, the surface tension adjusting additive (C) is used in order to improve the brilliance of the printed matter and to obtain a non-aqueous inkjet ink having excellent continuous ejection stability and drying property.

In the present invention, as the surface tension adjusting additive (C), surfactants such as siloxane-based, siloxane acrylic-based, fluorine-based, fluoroacrylic-based, acrylic-based, and acetylene glycol-based surfactants are used alone or in combination of two or more. Can be used in combination. Among them, a surface having a polysiloxane chain structure from the viewpoint of the ability to reduce surface tension with respect to an organic solvent (A) containing an alkylene glycol monoalkyl ether solvent (a1-1) and the storage stability of a non-aqueous inkjet ink. It is preferable to use a siloxane-based and / or siloxane acrylic-based surfactant, which is an additive for adjusting tension.

Examples of the siloxane-based surfactant include a modified polysiloxane compound in which an organic group is introduced into a part of the methyl group of polydimethylsiloxane. Examples of the modification include, but are limited to, polyether modification, methylstyrene modification, alcohol modification, alkyl modification, aralkyl modification, fatty acid ester modification, epoxy modification, amine modification, amino modification, mercapto modification and the like. It's not a thing. Moreover, these degeneration methods can be used in combination. Among the above-exemplified examples, the polyether-modified polysiloxane compound and the aralkyl-modified polysiloxane compound have high compatibility with the alkylene glycol monoalkyl ether solvent (a1-1), and the effects of the present invention are preferably exhibited. It is preferable from the viewpoint of improving the scratch resistance of the printed matter, and the polyether-modified polysiloxane compound is particularly preferable from the viewpoint of obtaining a non-aqueous inkjet ink having excellent continuous ejection stability.

Specific examples of the polyether-modified polysiloxane compound include KF-353A, KF-354L, KF6017, X-22-6551, AW-3 manufactured by Shin-Etsu Chemical Co., Ltd., and SAG001, SAG002, and SAG003 manufactured by Shin-Etsu Chemical Co., Ltd. , SAG005, SAG503A, SAG008, SAG010, 8019ADDITIVE, 8029ADDITIVE, 8032ADDITIVE, 8054ADDITIVE, 8526ADDITIVE, 8616ADDITIVE, 8526ADDITIVE, 8616ADDITIVE, 57ADDITIVE, 8616ADDITIVE, 57ADDITIVE, 67ADDITIVE, 57ADDITIVE, BYK-300, 302, 306, 307, 333, 330, 377, TEGO Glide 100, 110, 130, 406, 410, 415, 420, 432, 435, 440, 450, etc. manufactured by Evonik Degussa. ..

Specific examples of the aralkyl-modified polysiloxane compound include BYK-322 and 323 manufactured by Big Chemie Japan, KF-410 manufactured by Shin-Etsu Chemical Co., Ltd., SM 7001EX and SM 7002EX manufactured by Toray Dow Corning, and the like. Be done.

On the other hand, examples of the siloxane acrylic surfactant include a siloxane-modified acrylic resin which is a graft copolymer of an acrylic resin and a siloxane compound. Specific examples thereof include KP541, KP543, KP545 manufactured by Shin-Etsu Chemical Co., Ltd., BYK-3550, 3565, SILCLEAN3700 manufactured by Big Chemie Japan, LHP-810 manufactured by Kusumoto Kasei Co., Ltd., and the like.

The blending amount of the surface tension adjusting additive (C) is preferably 1% by mass or less, more preferably 0.01 to 1% by mass, and 0.02, based on the total amount of the non-aqueous inkjet ink. It is more preferably ~ 0.5% by mass, and most preferably 0.03 to 0.15% by mass. By suppressing the blending amount to 1% by mass or less, the surface tension adjusting additive (C) is oriented in a sufficient amount at the interface of the printed matter, the mottling of the printed matter is improved, and the brilliance is excellent regardless of the printing rate. The printed matter can be obtained.

[Binder resin (D)]
The non-aqueous inkjet ink of the present invention uses, for example, clear varnish, and by providing an overcoat layer on the upper part of the layer (ink layer) formed by using the non-aqueous inkjet ink, in addition to excellent brilliance, durability (durability ( A printed matter having scratch resistance, water resistance, solvent resistance, etc.) can be obtained. On the other hand, by blending the binder resin (D), it is possible to obtain a printed matter having excellent durability without providing the overcoat layer.

The binder resin (D) is selected from the viewpoints of solubility in an organic solvent (A) containing an alkylene glycol monoalkyl ether solvent (a1-1), continuous ejection stability, and brilliance and durability of printed matter. It is preferable to use at least one selected from the group consisting of acrylic resin, styrene-acrylic resin, polyester resin, and ketone resin.

Here, the weight average molecular weight (Mw) of the binder resin (D) is preferably 1,500 to 30,000. When Mw is 1,500 or more, a durable printed matter can be obtained. Further, when Mw is 30,000 or less, the arrangement of the scaly metal particles (B) is not obstructed, and the printed matter has both brilliance and durability. Further, the binder resin (D) having Mw is preferably used in that a non-aqueous inkjet ink having excellent continuous ejection stability can be obtained. The Mw is more preferably 1,800 to 20,000, and even more preferably 2,000 to 18,000. The weight average molecular weight (Mw) of the binder resin (D) can be measured by the same method as that of the pigment dispersant Mw described above.

The blending amount of the binder resin (D) is preferably 0.1 to 5% by mass with respect to the total amount of the non-aqueous inkjet ink. By setting the blending amount to 0.1% by mass or more, the adhesion of the non-aqueous inkjet ink to the recording medium is improved, and the printed matter has excellent durability. Further, when the content is 5% by mass or less, the arrangement of the scaly metal particles (B) is not obstructed, and the printed matter has excellent brilliance. From the viewpoint of more preferably exhibiting the above effects, the binder resin (D) more preferably contains 0.15 to 4% by mass, and further preferably 0.2 to 3% by mass, based on the total amount of the non-aqueous inkjet ink. preferable.

Generally, when the non-aqueous inkjet ink contains a binder resin, the surface of the printed matter may have irregularities due to the influence of the binder resin. In the case of the present invention, the influence of the unevenness prevents the scaly metal particles (B) from being arranged in parallel, and as a result, diffused reflection of incident light occurs and the surface of the printed matter looks white (whitening phenomenon). There is. As described above, the binder resin (D) in the present invention can prevent such a whitening phenomenon by setting the type of resin, the weight average molecular weight (Mw), and the blending amount within a suitable range, and from this point of view. A printed matter having excellent brilliance can be obtained.

When the non-aqueous inkjet ink of the present invention contains a binder resin (D), the binder resin (D) may be synthesized by a conventionally known method or a commercially available product may be used. Further, the binder resin (D) may be used alone or in combination of two or more.

Specific examples of commercially available binder resins (D) that can be used include BR-50, BR-52, MB-2539, BR-60, as acrylic resins of the Mitsubishi Chemical Corporation Dianal (registered trademark) BR series. BR-64, BR-73, BR-75, MB-2389, BR-80, BR-82, BR-83, BR-84, BR-85, BR-87, BR-88, BR-90, BR- 95, BR-96, BR-100, BR-101, BR-102, BR-105, BR-106, BR-107, BR-108, BR-110, BR-113, MB-2660, MB-2952, MB-3012, MB-3015, MB-7033, BR-115, MB-2478, BR-116, BR-117, BR-118, BR-122, ER-502,
As acrylic resin of Paraloid (registered trademark) series manufactured by Wilbur Ellis, A-11, A-12, A-14, A-21, B-38, B-60, B-64, B-66, B -72, B-82, B-44, B-48N, B-67, B-99N, DM-55,
BASF's JONCRYL® series styrene-acrylic resins include JONCRYL67, 678, 586, 611, 680, 682, 683, 690, 819, JDX-C3000, and JDXC3080.
As polyester resin of Nichigo Polyester (TM) series manufactured by Mitsubishi Chemical Corporation, TP-217, TP-220, TP-235, TP-236, TP-249, TP-290, TP-294, LP-011, LP -033, LP-035, LP-050, TP-219, LP-022, LP-050S50TO, SNT, NP-110S50EO, NP-120S45EO
AdBond LTH is a polyester resin of the Tego (registered trademark) series manufactured by EVONIC.
As the ketone resin of the Tego (registered trademark) series manufactured by EVONIC, VariPlus SK, VariPlus AP, and VariPlus 1201 are available.
K-90 is a ketone resin manufactured by Arakawa Chemical Industry Co., Ltd.
Each is listed.
Even if the resin is not listed above, it is any one of acrylic resin, styrene-acrylic resin, polyester resin, and ketone resin, and has a weight average molecular weight (Mw) of 1,500 to 30,000 or less. Any resin can be preferably used.

[Manufacturing method of non-aqueous inkjet ink]
The non-aqueous inkjet ink of the present invention can be produced by a conventionally known method, and specific examples thereof include the following methods.

First, in order to obtain scaly metal particles (B), a metal layer is formed on a sheet-like base material or on a peeling resin layer formed on the surface of the base material by a vacuum vapor deposition method. A plurality of the peeling resin layer and the metal layer may be alternately laminated to form a multilayer structure. Then, the scaly metal particles (B) are obtained by peeling the metal layer from the formed laminate, pulverizing and refining the metal layer.

Further, even if metal powder is produced by injecting water or gas at high pressure onto the molten metal (atomization method), and further pulverized and refined, scaly metal particles (B) are produced. Good.

Next, after mixing the obtained scaly metal particles (B), the organic solvent (A), and, if necessary, the surface tension adjusting additive (C), the binder resin (D), the pigment dispersant, and the like. , A paint shaker, a sand mill, a roll mill, a medialess disperser, a disperser, or the like can be used for mixing / dispersing treatment to produce a metal particle dispersion.

Then, the balance of the organic solvent (A), the balance of the surface tension adjusting additive (C), the balance of the binder resin (D), and others are added to the obtained metal particle dispersion so as to have desired ink characteristics. The non-aqueous inkjet ink of the present invention can be produced by adding an agent (for example, a colorant dispersion described later), mixing well, and then performing a filtration treatment to remove coarse particles.

When the non-aqueous inkjet ink further contains a colorant, a colorant dispersion in which the colorant is dispersed in the organic solvent (A) is produced by the same method as the method for producing the metal particle dispersion described above. After that, it may be mixed with a metal particle dispersion or the like.

[Physical characteristics of non-aqueous inkjet ink]
The non-aqueous inkjet ink of the present invention has a surface tension of 20 to 50 mN / m at 25 ° C. from the viewpoint of a balance between continuous ejection stability from an inkjet print head, reliability of dot formation after landing, and dryness. It is preferably 21 to 40 mN / m, more preferably 22 to 30 mN / m. From the same viewpoint, the viscosity at 25 ° C. is preferably 1 to 15 mPa · s, more preferably 1.5 to 10 mPa · s, and even more preferably 2 to 6 mPa · s.

The surface tension is a value measured by wetting a platinum plate with ink in an environment of 25 ° C. using an automatic surface tension meter CBVP-Z manufactured by Kyowa Interface Science Co., Ltd. The viscosity is a value measured using a TVE25L type viscometer manufactured by Toki Sangyo Co., Ltd. under the condition of a rotor rotation speed of 50 rpm in an environment of 25 ° C.

[Printed matter]
The non-aqueous inkjet ink of the present invention is applied to a recording medium described later by an inkjet printing method. Then, after performing a drying treatment as needed, a printed matter is obtained. The drying treatment includes, for example, a method of blowing warm air onto the non-aqueous inkjet ink on the recording medium, a method of throwing or passing the recording medium into a heater such as an oven, and the non-aqueous inkjet ink of the recording medium. There is a method in which the surface to which the ink is not applied is brought into contact with the heat source, and a plurality of them may be combined.

Further, as described above, the printed matter of the present invention may have an overcoat layer formed on the upper part of the ink layer. The overcoat layer may be formed by printing a conventionally known clear varnish by, for example, a plate printing method such as an offset printing method or a gravure printing method. Further, as the composition for forming the overcoat layer, a composition excluding the scaly metal particles (B) from the non-aqueous inkjet ink of the present invention (non-aqueous inkjet clear ink) may be used. Further, an ultraviolet curable inkjet clear ink having a conventionally known configuration (for example, those described in JP-A-2007-31667 and JP-A-2011-57744) can also be used.

[recoding media]
The recording medium to which the non-aqueous inkjet ink of the present invention is applied is not particularly limited, and plastic substrates such as soft vinyl chloride, hard vinyl chloride, polystyrene, foamed styrene, PMMA, polypropylene, polyethylene, polyester, PET, and polycarbonate, and these. A mixed or modified product of the above, high-quality paper, art paper, coated paper, cast-coated paper, paper base material such as cardboard, metal base material such as stainless steel and aluminum, glass base material and the like can be used.
Among them, a plastic base material or a paper base material is preferably used from the viewpoint of price and processability, and particularly preferably one selected from the group consisting of a soft vinyl chloride sheet, a hard vinyl chloride sheet, corrugated cardboard, and coated paper. Be done. On the other hand, a metal base material or a glass base material is preferably used because it is characteristically capable of printing with high image quality.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not particularly limited to the Examples. In the following description, "parts" and "%" represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

(Metal pigment)
Table 1 shows the metal pigments used in the following examples and comparative examples.
The average particle size (D50) of the metal pigment shown in Table 1 is a value measured using a laser diffraction type particle size distribution measuring device (Microtrac MT3300EXII) manufactured by Nikkiso Co., Ltd., particle permeability: reflection, and calculation mode: MT3000II. is there. The average thickness (t) is a value calculated by the above method using a scanning electron microscope (JSM-6390LA) manufactured by JEOL Ltd.

(Additive for adjusting surface tension (C))
Table 2 shows the surface tension adjusting additive (C) used in the following Examples and Comparative Examples.

(Binder resin)
Table 3 shows the binder resins used in the following examples and comparative examples.
The weight average molecular weight (Mw) shown in Table 3 is a value measured according to the above conditions using a TSKgel column (manufactured by Tosoh Corporation) and a GPC equipped with an RI detector (manufactured by Tosoh Corporation, HLC-8320 GPC). is there.

(Example 1)
8 parts of 1-methoxy-2-propanol as an organic solvent (A), 30 parts of ethylene glycol monophenyl ether, 59 parts of diethylene glycol diethyl ether, and M1 (t: 20 nm, contained metal: In) as a metal pigment (B). ), 0.1 part of S1 (polysiloxane chain-containing, siloxane-modified acrylic) as the surface adjusting additive (C), and R1 (acrylic, Mw: 15,000) as the binder resin (D). 0.9 parts were sequentially added to the mixing container while stirring with a disper. Then, the liquid temperature was raised to 50 ° C., and stirring was continued until the binder resin was completely dissolved until the liquid temperature was sufficiently uniform. After that, filtration was performed with a filter to remove coarse particles causing head clogging, and a non-aqueous inkjet ink 1 was prepared.
After filling the produced non-aqueous inkjet ink 1 into VJ-628 (an inkjet printer manufactured by Muto Kogyo Co., Ltd.), the following printing test is performed in an environment of room temperature of 25 ° C. using a soft vinyl chloride sheet as a recording medium, and continuous ejection is performed. Stability, brilliance (printing rate 100%), and dryness were evaluated. The results are shown in Table 4.

(Continuous discharge stability evaluation)
After printing a solid image (width 0.5 m x length 10 m) with a printing rate of 100% for non-aqueous inkjet ink with the above printer with the printer heater set to 45 ° C, check the degree of nozzle omission that occurred after printing. did. The evaluation criteria were as follows, and 3 or more was considered good.
5: Nozzle omission less than 2% 4: Nozzle omission 2% or more and less than 4% 3: Nozzle omission 4% or more, less than 7% 2: Nozzle omission 7% or more and less than 10% 1: Nozzle omission 10% or more

(Evaluation of brilliance (printing rate 100%))
A solid image (width 3 cm × length 15 cm) with a printing rate of 100% of non-aqueous inkjet ink was printed by the above printer in which the printer heater was set to 45 ° C. The printed matter was dried at room temperature for 24 hours, and then the glossiness was evaluated by measuring the 20 ° gloss value using a gloss meter (micro-tri-gloss manufactured by BYK-Gardner). The evaluation criteria were as follows, and 3 or more was considered good.
5: Gloss value 350 or more 4: Gloss value 300 or more and less than 350 3: Gloss value 250 or more and less than 300 2: Gloss value 200 or more and less than 250 1: Gloss value less than 200

(Dryness evaluation)
A solid image (width 3 cm × length 15 cm) with a printing rate of 100% of non-aqueous inkjet ink was printed by the above printer with the printer heater turned off. Immediately after printing is completed, place the printed matter on a hot plate at 60 ° C, and rub the printed surface three times with a cotton swab every 15 seconds from the start of standing until the ink color does not transfer to the cotton swab. By measuring, the dryness was evaluated. The evaluation criteria were as follows, and 3 or more was considered good.
No color transfer to the cotton stick in 5:90 seconds or less 4: No color transfer to the cotton stick in more than 120 seconds in 120 seconds or less 3: No color transfer to the cotton stick in more than 120 seconds in 180 seconds or less 2: Color transfer to the cotton stick disappeared in more than 180 seconds and less than 210 seconds 1: Even after 210 seconds, color transfer to the cotton stick was observed.

(Examples 2 to 39, Comparative Examples 1 to 8)
Non-aqueous inkjet inks 2-39 and comparative non-aqueous inkjet inks 1-are the same operations as in Example 1 except that the composition of the organic solvent (A) in Example 1 was changed to the composition shown in Table 4. 8 was prepared. Although details will be described later, the comparative non-aqueous inkjet inks 3 to 8 are reproductions of the non-aqueous inkjet inks described in Examples of Patent Documents 1 to 3. Then, a printing test was performed in the same manner as in Example 1 in the same manner as in Example 1, and continuous ejection stability, brilliance (printing rate 100%), and dryness were evaluated (each evaluation method is Example 1). Similar to). The results are shown in Table 4.

(Examples 40 to 48, Comparative Examples 9 to 11)
Non-aqueous inkjet inks 40 to 48 and comparative non-aqueous inkjet inks 9 to 9 are operated in the same manner as in Example 1 except that the organic solvent (A) and the metal pigment (B) are changed to the compositions shown in Table 5. 11 was prepared. Then, a printing test was carried out in the same manner as in Example 1 to evaluate continuous ejection stability, brilliance (printing rate 100%), and dryness (each evaluation method is the same as in Example 1). The results are shown in Table 5.

(Example 49 to 53, Comparative Example 12)
Non-aqueous inkjet inks 47 to 53 and comparative non-aqueous inkjet inks 12 were produced by the same operations as in Example 1 except that the surface adjusting additive (C) was changed to the composition shown in Table 6. In Comparative Example 12, the system did not contain the surface adjusting additive (C). Then, a printing test was carried out in the same manner as in Example 1 to evaluate continuous ejection stability, brilliance (printing rate 100%), and dryness (each evaluation method is the same as in Example 1). The results are shown in Table 6.

(Examples 54 to 63)
Non-aqueous inkjet inks 54 to 63 were prepared in the same manner as in Example 1 except that the binder resin (D) was changed to the composition shown in Table 7. In Example 54, the system did not contain the binder resin (D). Then, a printing test was carried out in the same manner as in Example 1 to evaluate continuous ejection stability, brilliance (printing rate 100%), and dryness (each evaluation method is the same as in Example 1). The results are shown in Table 7.

The components used in Tables 4 to 7 are as follows.
(Organic solvent)
・ EHG (Ethylene Glycol Monoethylhexyl Ether)
・ EHDG (diethylene glycol monoethylhexyl ether)
・ PhPG (Propylene Glycol Monophenyl Ether)
・ PhG (Ethylene Glycol Monophenyl Ether)
・ PhDG (diethylene glycol monophenyl ether)
-BzG (Ethylene Glycol Monobenzyl Ether)
-DdDG (diethylene glycol monododecyl ether)
・ MP (1-methoxy-2-propanol)
・ MB (3-methoxybutanol)
・ MDPG (dipropylene glycol monomethyl ether)
・ BDPG (dipropylene glycol monobutyl ether)
・ MTeG (Tetraethylene Glycol Monomethyl Ether)
-BTeG (Tetraethylene Glycol Monobutyl Ether)
・ DMDG (diethylene glycol dimethyl ether)
・ DEDG (diethylene glycol diethyl ether)
・ MEDG (diethylene glycol methyl ethyl ether)
・ DMDPG (dipropylene glycol dimethyl ether)
-DMTeG (Tetraethylene Glycol Dimethyl Ether)
・ MBA (3-methoxybutyl acetate)
・ BG Ac (Ethylene Glycol Monobutyl Ether Acetate)
・ EDGAc (diethylene glycol monoethyl ether acetate)
・ MPGAc (Propylene Glycol Monomethyl Ether Acetate)
・ GBL (Gamma-Butyrolactone)
-Butyl acetate (n-butyl acetate)

From the results of Tables 4, 5 and 7, the alkylene glycol monoalkyl ether solvent (a1-1) represented by the general formula 1 was used as the organic solvent (A) in an amount of 10 to 10 based on the total amount of the organic solvent (A). By using a non-aqueous inkjet ink containing 75% by mass and containing 0.1 to 5% by mass of scaly metal particles (B) having an average thickness (t) of 1 to 50 nm, continuous ejection stability and brilliance are obtained. Regarding the dryness, each score was 3 points or more, and the average score was 3.5 points or more, and it was confirmed that all the characteristics could be satisfied at a high level.
Furthermore, from the results in Table 6, it was confirmed that when the surface tension adjusting additive (C) has a polysiloxane chain structure, it has particularly excellent qualities in terms of continuous discharge stability and brilliance.

On the other hand, as in Comparative Example 1, when the blending amount of the alkylene glycol monoalkyl ether solvent (a1-1) is less than 10% by mass with respect to the total amount of the organic solvent (A), the printed matter is inferior in brilliance. On the contrary, when the blending amount of the alkylene glycol monoalkyl ether solvent (a1-1) is more than 75% by mass with respect to the total amount of the organic solvent (A) as in Comparative Example 2, continuous discharge stability is achieved. It becomes a non-aqueous inkjet ink that is inferior in properties and drying property.

Further, as in Comparative Example 9, the average thickness of the scaly metal particles does not satisfy the conditions of the present application, or as in Comparative Example 10, the scaly metal particles using non-scaly metal particles are also used. It was confirmed that a non-aqueous inkjet ink having inferior continuous ejection stability or brilliance of printed matter was obtained. Further, in Comparative Example 11, the content of the scaly metal particles (B) was larger than the preferable range, and the continuous discharge stability was deteriorated. Further, as in Comparative Example 12, when the surface adjusting additive (C) is not contained, continuous discharge stability is satisfied even if the conditions of the present invention regarding the organic solvent (A) and the scaly metal particles (B) are satisfied. It was also found that it is a non-aqueous inkjet ink that is inferior in the brilliance of printed matter.

As described above, the configuration of the present invention is indispensable in order to obtain a non-aqueous inkjet ink that satisfies all of continuous ejection stability, brilliance of printed matter, and dryness at a high level.

In addition, Comparative Example 3 is a reproduction of Example 1 of Patent Document 1 with respect to the configuration other than the type of scaly metal particles (B) used. Similarly, Comparative Example 4 is Example 1 of Patent Document 2. , Comparative Example 6 is a reproduction of Example 4 of Patent Document 2, and Comparative Example 7 is a reproduction of Example 7 of Patent Document 3. In all cases, the continuous ejection stability and the brilliance of the printed matter are inferior, and from this, a certain amount of alkylene glycol monoalkyl ether solvent (a1-) is required to achieve both characteristics at the same time. It turns out that 1) is indispensable.

Further, Comparative Example 5 shows the types and amounts of the scaly metal particles (B), the surface adjusting additive (C), and the binder resin (D) contained in the non-aqueous inkjet ink of Comparative Example 4. It was combined with the non-aqueous inkjet ink of Example 1, and the continuous ejection stability was improved to a good level as compared with Comparative Example 4, while the brilliance of the printed matter remained insufficient. As a result, the dryness deteriorated. Further, Comparative Example 8 is a system in which the tetraethylene glycol monomethyl ether contained in the non-aqueous inkjet ink of Comparative Example 7 is changed to tetraethylene glycol dimethyl ether. As described above, Patent Document 3 describes that it is preferable to contain tetraethylene glycol dimethyl ether, and the purpose is to confirm the effect. However, as a result of the evaluation, it was found that the brilliance of the printed matter did not improve, and the dryness rather deteriorated. From these results, it is clear that the non-aqueous inkjet ink of the present invention cannot be easily conceived from Patent Documents 1 to 3.

(Example 64)
A yellow pigment dispersion containing 30% by mass of yellow pigment and 55% by mass of diethylene glycol diethyl ether is prepared by the same material and method as the pigment dispersion 1-3 described in Japanese Patent Application Laid-Open No. 2014-214255. Manufactured. Next, 99 parts of the non-aqueous inkjet ink 1 produced in Example 1 and 1 part of the yellow pigment dispersion were put into a mixing container, stirred so as to be sufficiently uniform, and then filtered through a filter. This was performed to prepare a non-aqueous inkjet ink 64.

Then, a printing test was carried out in the same manner as in Example 1 to evaluate continuous ejection stability, brilliance (printing rate 100%), and dryness (each evaluation method is the same as in Example 1). As a result, the score was 5 points in all the evaluations, and it was confirmed that all the characteristics were satisfied at a high level.

Claims (7)

A non-aqueous inkjet ink containing an organic solvent (A), scaly metal particles (B), and an additive for adjusting surface tension (C).
The organic solvent (A) contains 10 to 75% by mass of an alkylene glycol monoalkyl ether solvent (a1-1) represented by the following general formula 1 with respect to the total amount of the organic solvent (A).
The scaly metal particles (B) are scaly particles having an average thickness (t) of 1 to 50 nm.
A non-aqueous inkjet ink in which the content of the scaly metal particles (B) is 0.1 to 5% by mass with respect to the total amount of the non-aqueous inkjet ink.

R1- (O-R2) _n1- OH [General formula 1]

(In the general formula 1, R1 represents a hydrocarbon group having 6 to 12 carbon atoms, R2 represents an alkylene group having 2 or 3 carbon atoms, and n1 represents 1 or 2). The non-aqueous inkjet ink according to claim 1, wherein the scaly metal particles (B) contain at least one selected from the group consisting of Al, In, and Cu as metal elements. The non-aqueous inkjet according to claim 1 or 2, wherein the organic solvent (A) further contains an alkylene glycol dialkyl ether solvent (a2) and / or an alkylene glycol monoalkyl ether monoacetate solvent (a3). ink. The organic solvent (A) further contains an alkylene glycol monoalkyl ether solvent (a1-2) represented by the following general formula 2.
Claims 1 to 5, wherein the ratio of the blending amount of the alkylene glycol monoalkyl ether solvent (a1-2) to the blending amount of the alkylene glycol monoalkyl ether solvent (a1-1) is 10 to 500% by mass. 3. The non-aqueous inkjet ink according to any one of 3.

R3- (O-R4) _n2- OH [General formula 2]

(In the general formula 2, R3 represents a hydrocarbon group having 1 to 5 carbon atoms, R4 represents an alkylene group having 2 to 6 carbon atoms, and n2 represents an integer of 1 to 4 carbon atoms.) The non-aqueous inkjet ink according to any one of claims 1 to 4, wherein the surface tension adjusting additive (C) contains a surface tension adjusting additive having a polysiloxane chain structure. The non-aqueous inkjet ink according to any one of claims 1 to 5, which is used for printing on any of a plastic base material, a paper base material, a metal base material, and a glass base material. A printed matter obtained by printing the non-aqueous inkjet ink composition according to any one of claims 1 to 6 on a base material.