JP2016138211A - Nonaqueous inkjet ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous inkjet ink capable of suppressing clogs of heads of an inkjet printer and reducing discharge defects of ink such as non-discharge of ink or flight bend of ink drop.SOLUTION: There is provided a nonaqueous inkjet ink containing a coloring material, a nonaqueous solvent and polyhydroxystearic acid alkylamide amine salt.SELECTED DRAWING: None

Description

  The present invention relates to a non-aqueous inkjet ink used in an inkjet printer.

  The ink jet recording method is a method in which a highly fluid ink jet ink is ejected as ink particles from a fine head nozzle to record an image on a printing medium such as paper, and is a relatively inexpensive device with high resolution and high quality. In recent years, it has become widespread rapidly. As inks used in such an ink jet recording method, various so-called non-aqueous ink jet inks in which a pigment is finely dispersed in a water-insoluble solvent have been proposed. Non-water-based inkjet inks, unlike water-based inks, have excellent on-machine stability and can obtain a print surface that does not stick even when superimposed on a print surface printed by a PPC copier or laser printer. Has the advantage of

  In general, when a non-aqueous ink jet ink is used for a long period of time, solid matter may be deposited near the nozzles of the ink jet head and clogging may occur. Such clogging induces ejection defects such as flying bends and scattering of ink droplets, and image defects may occur. Conventionally, the cause of the clogging of the ink has been caused by the change over time due to the thickening of the ink due to the concentration of the ink in the nozzle, the coarse particles floating in the ink due to poor dispersion, and the dispersion stability of the pigment is poor. It was thought to be a pigment aggregate. Therefore, conventionally, in accordance with the above causes, the increase in viscosity is suppressed by selecting a solvent, a resin, etc., or the aggregated particles are separated and removed by controlling the average particle diameter of the pigment, or specific to the pigment. Means such as adsorbing a dispersant to suppress pigment aggregation have been studied.

After that, the main cause of the solids agglomerated in the vicinity of the nozzles is actually water-soluble metal salts despite the fact that they are non-aqueous inks. Ink raw materials (pigments, resins, solvents and other additives) It was found that the component dissolved in the water contained in a trace amount of water is deposited as a solid in the vicinity of the member in contact with the ink, that is, the nozzle by evaporation of the water. Among these, metal components such as calcium and magnesium tend to react with lower fatty acids present in the ink and fluorine in the ink path member to generate insoluble components. Then, the knowledge for suppressing the bad influence of such a water-soluble metal salt (solid substance) is proposed (for example, refer patent documents 1-2).
Patent Document 1 proposes an ink-jet ink that reduces the amount of water-soluble solids by regulating the contents of calcium and magnesium that cause water-soluble metal salts to a predetermined amount or less.
Patent Document 2 proposes an ink-jet ink in which water-soluble solids in the vicinity of a nozzle are reduced by regulating the water-soluble component to a predetermined amount or less.

JP 2011-89043 A JP 2011-195799 A

  However, both of the ink-jet inks described in Patent Documents 1 and 2 are intended to reduce water-soluble solid substances that cause clogging of nozzles, but are completely free of alkaline earth metals such as Ca and Mg. It is technically difficult to eliminate, and there is a limit to reducing the causative substances. As a result, clogging of the nozzles could not be completely suppressed, and the effect of suppressing ink ejection defects was insufficient.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to suppress clogging of the head of an ink jet printer and reduce ink ejection defects such as non-ejection of ink and flying bending of ink droplets. It is to provide a non-aqueous inkjet ink.

The present invention for solving the above problems is as follows.
(1) A non-aqueous inkjet ink containing a coloring material, a non-aqueous solvent, and a polyhydroxystearic acid alkylamidoamine salt.

  ADVANTAGE OF THE INVENTION According to this invention, the non-aqueous inkjet ink which can suppress clogging of the head of an inkjet printer and can reduce ink ejection defects, such as non-ejection of an ink and the flight curve of an ink droplet, can be provided.

The non-aqueous inkjet ink of the present invention is characterized by containing a coloring material, a non-aqueous solvent, and a polyhydroxystearic acid alkylamidoamine salt.
The non-aqueous ink-jet ink of the present invention (hereinafter sometimes referred to simply as “ink”) is a polyhydroxystearic acid alkylamidoamine salt that contains insoluble components such as lower fatty acid salts caused by alkali metals and alkaline earth metals. By adsorbing and stably dispersing in the ink, accumulation of the insoluble component in the nozzle of the inkjet head is suppressed, and ink ejection defects such as non-ejection of ink and flying bending of ink droplets are reduced. .
Below, the non-aqueous inkjet ink of this invention is demonstrated.

[Polyhydroxystearic acid alkylamidoamine salt]
The polyhydroxystearic acid alkylamidoamine salt used in the present invention is a salt of a condensate of polyhydroxystearic acid and alkylenediamine.
In the above-mentioned salt, the hydroxyl group bonded to the stearic acid moiety is preferably located in the middle of the carbon chain, specifically, preferably bonded to the carbon of position numbers 9 to 16 of carbon in stearic acid. More preferably, it is bonded to the number 12 carbon. By bonding at this position, the intramolecular polarity of the polyhydroxystearic acid alkylamide salt is lowered and the solubility in a non-aqueous solvent is improved, so that the lower fatty acid salt, which is an insoluble component, is adsorbed in the ink. Can be dispersed more stably. Moreover, as carbon number of the alkylene group of an alkylamidoamine part, 1-5 are preferable and 2-4 are more preferable. Furthermore, examples of the acid from which the salt is derived include phosphoric acid, hydrochloric acid, nitric acid, and sulfuric acid. Among these, phosphoric acid is preferable. Further, the amine that does not participate in the amide bond of the alkylene diamine moiety is preferably a tertiary amine.
Examples of the polyhydroxystearic acid alkylamidoamine salt include a salt of a condensate of polyhydroxystearic acid and dimethylaminopropylamine, and more specifically, a phosphorus represented by the following structural formula (1). Acid salts.

In the polyhydroxystearic acid alkylamidoamine salt of the structural formula (1), the degree of polymerization is preferably 5 to 7.
The number average molecular weight is preferably 800 to 1300, and the weight average molecular weight is preferably 1300 to 2400. The dispersity is preferably 1.625 to 1.846.

  In the present invention, the content of the polyhydroxystearic acid alkylamidoamine salt in the ink may be the same as that of the substance causing the insoluble component, and is preferably 0.000001 to 5% by mass, for example. From the viewpoints of ink viscosity and storage stability, 0.01 to 1% by mass is more preferable.

[Color material]
Examples of the color material contained in the non-aqueous inkjet ink of the present invention include pigments and dyes. Each will be described below.

(Pigment)
As the pigment, organic pigments such as azo pigments, phthalocyanine pigments, polycyclic pigments, dyed lake pigments, and inorganic pigments can be used. Examples of the azo pigment include a soluble azo lake pigment, an insoluble azo pigment, and a condensed azo pigment. Examples of phthalocyanine pigments include metal phthalocyanine pigments and metal-free phthalocyanine pigments. Polycyclic pigments include quinacridone pigments, perylene pigments, perinone pigments, isoindoline pigments, isoindolinone pigments, dioxysazine pigments, thioindigo pigments, anthraquinone pigments, quinophthalone pigments, metal complex pigments. And diketopyrrolopyrrole (DPP). Representative examples of inorganic pigments include carbon black and titanium oxide. These pigments may be used alone or in combination of two or more.

  In the non-aqueous inkjet ink of the present invention, when a pigment is used as a color material, the content is usually 0.01 to 20% by mass, and 1 to 15% by mass from the viewpoint of printing density and ink viscosity. Preferably, the content is 3 to 10% by mass.

(dye)
As dyes, azo dyes, metal complex dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinoneimine dyes, xanthene dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, phthalocyanine dyes, Mention may be made of oil-soluble dyes such as metal phthalocyanine dyes. These dyes may be used alone or in combination of two or more.

  In the non-aqueous ink jet ink of the present invention, when a dye is used as a coloring material, the content is usually 0.01 to 10% by mass, and 0.3 to 5% by mass from the viewpoint of printing density and ink viscosity. It is preferably 0.5 to 3% by mass.

  In the above color materials, soluble azo lake pigments and the like contain a relatively large amount of components such as Ca. Therefore, in the case of inks using these color materials, the effects of the present invention are more remarkably exhibited.

[Non-aqueous solvent]
As the non-aqueous solvent, any of a non-polar organic solvent and a polar organic solvent can be used. These may be used alone or in combination. In the present invention, as the non-aqueous solvent, it is preferable to use a water-insoluble organic solvent that is not uniformly mixed with the same volume of water at 1 atm.

  Preferable examples of the nonpolar organic solvent include petroleum hydrocarbon solvents such as aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, and aromatic hydrocarbon solvents. Examples of the aliphatic hydrocarbon solvent and the alicyclic hydrocarbon solvent include non-aqueous solvents such as paraffinic, isoparaffinic, and naphthenic solvents, and commercially available products include 0 Solvent L, 0 Solvent M, 0 Solvent H, Cactus normal paraffin N-10, Cactus normal paraffin N-11, Cactus normal paraffin N-12, Cactus normal paraffin N-13, Cactus normal paraffin N-14, Cactus normal paraffin N-15H, Cactus normal paraffin YHNP Cactus normal paraffin SHNP, Isosol 300, Isosol 400, Teclean N-16, Teclean N-20, Teclean N-22, AF Solvent No. 4, AF Solvent No. 5, AF Solvent No. 6, AF Solvent No. 7, Futezol 160, Naphthezol 200, Naphthezol 220 (all manufactured by JX Nippon Oil & Energy Corporation); Isopar G, Isopar H, Isopar L, Isopar M, Exol D40, Exol D60, Exol D80, Exol D95, Exol D110, Exol D130 (Both manufactured by TonenGeneral Sekiyu KK) and the like can be preferably mentioned. As the aromatic hydrocarbon solvent, grade alkene L, grade alkene 200P (all manufactured by JX Nippon Oil & Energy Corporation), Solvesso 100, Solvesso 150, Solvesso 200, Solvesso 200ND (all manufactured by TonenGeneral Sekiyu KK), etc. Can be preferably mentioned. The distillation initial boiling point of the petroleum hydrocarbon solvent is preferably 100 ° C. or higher, more preferably 150 ° C. or higher, and even more preferably 200 ° C. or higher. The distillation initial boiling point can be measured in accordance with JIS K0066 “Method for Distillation Test of Chemical Products”.

  Preferred examples of the polar organic solvent include fatty acid ester solvents, higher alcohol solvents, higher fatty acid solvents and the like. For example, isononyl isononanoate, isodecyl isononanoate, octyl decanoate, methyl laurate, isopropyl laurate, hexyl laurate, octyl laurate, isopropyl myristate, isopropyl palmitate, hexyl palmitate, isooctyl palmitate, isostearyl palmitate , Methyl oleate, ethyl oleate, isopropyl oleate, butyl oleate, hexyl oleate, methyl linoleate, ethyl linoleate, isobutyl linoleate, butyl stearate, hexyl stearate, isooctyl stearate, isopropyl isostearate, pivalin The number of carbon atoms in one molecule such as acid 2-octyldecyl, soybean oil methyl, soybean oil isobutyl, tall oil methyl, and tall oil isobutyl is 13 or more, Preferably, the number of carbon atoms in one molecule such as 16-30 fatty acid ester solvent; isomyristyl alcohol, isopalmityl alcohol, isostearyl alcohol, oleyl alcohol, isoeicosyl alcohol, decyltetradecanol, etc. Is a 12-20 higher alcohol solvent; lauric acid, isomyristic acid, palmitic acid, isopalmitic acid, α-linolenic acid, linoleic acid, oleic acid, isostearic acid and the like have 12 or more carbon atoms, preferably 14 to 20 higher fatty acid solvents and the like. The boiling point of polar organic solvents such as fatty acid ester solvents, higher alcohol solvents and higher fatty acid solvents is preferably 150 ° C. or higher, more preferably 200 ° C. or higher, and 250 ° C. or higher or atmospheric pressure. It is even more preferred that no boiling point is observed since it does not decompose and evaporate below.

  These non-aqueous solvents may be used alone or in combination of two or more as long as a single phase is formed. Moreover, you may include another organic solvent in the range which can form a single phase with the non-aqueous solvent to be used.

  The content of the non-aqueous solvent is preferably 60% by mass or more, more preferably 70 to 95% by mass, and still more preferably 85 to 93% by mass with respect to the total amount of the ink.

[Other ingredients]
In the non-aqueous ink-jet ink of the present invention, in addition to the above components, various additives that are usually used in the field can be included as needed within the range not impairing the effects of the present invention.
Additives include surfactants such as anionic, cationic, amphoteric or nonionic surfactants, antioxidants such as dibutylhydroxytoluene, propyl gallate, tocopherol, butylhydroxyanisole, and nordihydroguaiare. Examples include tic acid, and pigment dispersants such as modified polyacrylates, modified polyurethanes, polyester polyamines, acid esters, and the like.

  The recording medium for recording using the non-aqueous inkjet ink of the present invention is not particularly limited, and printing paper such as plain paper, coated paper and special paper, cloth, inorganic sheet, film, OHP sheet, and these. An adhesive sheet having an adhesive layer on the back surface can be used as the substrate. Among these, printing paper such as plain paper and coated paper can be preferably used.

  Plain paper is printing paper on which an ink receiving layer, a film layer, or the like is not formed. Examples of plain paper include high quality paper, medium quality paper, PPC paper, renewal paper, and recycled paper. As the coated paper, so-called coated printing paper or inkjet coated paper can be preferably used. Coated printing paper is printing paper conventionally used for letterpress printing, offset printing, gravure printing, etc., and uses a paint containing an inorganic pigment such as clay or calcium carbonate and a binder such as starch, It is a printing paper in which a coating layer is provided on the surface of paper or medium quality paper. Coated printing paper can be applied to fine coated paper, high-quality lightweight coated paper, medium-weight lightweight coated paper, high-quality coated paper, medium-quality coated paper, art paper, cast coated paper, etc., depending on the coating amount and coating method. being classified. Examples of the ink-jet coated paper include matte paper and photo glossy paper.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Examples 1-5, Comparative Examples 1-3]
In each of the examples and comparative examples, a preparation liquid was prepared by premixing with the components and content (% by mass) shown in Table 1. The obtained preparation liquid was dispersed with Dynomill KDL-A (manufactured by Shinmaru Enterprises Co., Ltd.). The obtained mixture was filtered through a 3.0 μm membrane filter to obtain non-aqueous inkjet inks of Examples and Comparative Examples.
The content of divalent metals (Ca, Mg), which are non-ejection causing substances, was about 0.05 ppm in the entire ink as measured by an ICP emission analyzer.
In Examples 3 and 4 in Table 1, the content of the fatty acid ester solvent is rounded off. The exact numerical value is 70.999995 mass% in Example 3 and 70.99999 mass% in Example 4.

Details of the components used in each example are shown below.
(1) Color material Copper phthalocyanine blue (pigment, manufactured by DIC Corporation, FASTOGEN Blue LA5380)
Carbon black (pigment, manufactured by Mitsubishi Chemical Corporation, MA-230)
Permanent Red 2B (pigment, manufactured by Dainichi Seika Co., Ltd., ECR-102)
Oil-soluble dye (dye, manufactured by Orient Chemical Industry Co., Ltd., OIL BLUE 613)
(2) Higher alcohol solvent Isostearyl alcohol Cetyl alcohol (3) Fatty acid ester solvent Octyl laurate Octyl decanoate (4) Petroleum hydrocarbon solvent AF Solvent No. 4 (manufactured by JX Nippon Oil & Energy Corporation)
AF Solvent No. 5 (manufactured by JX Nippon Oil & Energy Corporation)
(5) Pigment dispersant Solsperse 16000 (Nihon Lubrizol Co., Ltd.)
Solsperse 18000 (Nippon Lubrizol Co., Ltd.)
(6) Additive polyhydroxystearic acid alkylamidoamine salt (manufactured by Nikko Chemicals Co., Ltd., in the above-described structural formula (1), n is 5-6, number average molecular weight by GPC measurement is 1055, weight average molecular weight Is 1822 and the dispersity is 1.727.)
Salt of long-chain polyamidoamine and polar acid ester (BYK108, manufactured by BYK Japan)
Polyoxyethylene alkyl ether phosphoric acid (Nikko Chemicals, DDP-2)

Each of the inks after preparation is introduced into an inkjet printer “Olfis EX9050” (trade name: Riso Kagaku Kogyo Co., Ltd.), and a solid image is continuously printed for 10 hours once a week in a 40 ° C. environment. This was continued for one month. Check the solid image after one month, measure the number of nozzles where the deviation of the dot landing position occurred, measure the number of nozzles where the deviation of all nozzles (100) occurred, and evaluated according to the following evaluation criteria .
~Evaluation criteria~
○: Less than 5% Δ: Less than 10% ×: 10% or more

From Table 1, all of Examples 1 to 6 using polyhydroxystearic acid alkylamidoamine salts as additives (as coloring materials, Examples 1 to 5 use pigments, and Example 6 uses dyes). It can be seen that the discharge performance was excellent. On the other hand, Comparative Examples 1, 2, and 3 respectively used an example in which no additive was used, an example in which a salt of a long-chain polyamidoamine and a polar acid ester was used as the additive, and the same polyoxyalkyl ether. Although it is an example, all were inferior to discharge performance.
Moreover, it turns out that discharge performance is more excellent when the content of the said additive is made into the range of 0.000005-5 mass% by the comparison of Examples 1-4 which varied content of the additive.

Claims (1)

  A non-aqueous inkjet ink comprising a coloring material, a non-aqueous solvent, and a polyhydroxystearic acid alkylamidoamine salt.