JP2014019770A - Colored resin particle dispersion and ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a colored resin particle dispersion excellent in water resistance, as well as in marker resistance and rubfastness.SOLUTION: A colored resin particle dispersion is obtained by dispersing a dispersion phase comprising a nonaqueous solvent B, a dye, a resin, and an acidic dispersant into a continuous phase comprising a nonaqueous solvent A and a basic dispersant to prepare an oil-in-oil emulsion, wherein the nonaqueous solvent B has a solubility in the nonaqueous solvent A at 23°C of 3 g/100 g or less, and a boiling point lower than that of the nonaqueous solvent A; and removing the nonaqueous solvent B from the oil-in-oil emulsion by reducing pressure and/or heating. The basic dispersant has a higher solubility in the nonaqueous solvent A than in the nonaqueous solvent B, and the resin has a higher solubility in the nonaqueous solvent B than in the nonaqueous solvent A.

Description

  The present invention relates to a colored resin particle dispersion and an ink.

  Color materials for printing ink are roughly classified into dyes and pigments. When using dye, there exists an advantage that coloring is good. In addition, there is an advantage that it is excellent in abrasion resistance, particularly scratch resistance, compared with a pigment. However, there is a problem that the water resistance and marker resistance of the dye itself are low.

  On the other hand, there is a method of providing an ink that is excellent in water resistance and marker resistance as well as scratch resistance while making use of the coloring property of the dye by including the dye in the form of colored resin particles. is there. Here, as the resin, it is desirable that the ink has a property of imparting scratch resistance, water resistance and marker resistance to the ink.

  Patent Document 1, Patent Document 2 and Non-Patent Document 1 use an organic solvent A and an organic solvent B which is almost incompatible with the organic solvent A, and a dispersed phase and an organic material containing the organic solvent B and a resin. A polymer particle dispersion in which polymer particles are dispersed in the organic solvent A is prepared by removing the organic solvent B from the dispersion by reducing the pressure or heating, after preparing a dispersion composed of a continuous phase containing the solvent A. Has been proposed.

  That is, by dissolving and encapsulating a resin that does not dissolve in the organic solvent A in the organic solvent B and dispersing it in the organic solvent A to be a continuous phase, the organic solvent B is then removed by reducing or heating, It has been proposed to obtain a polymer particle dispersion in which polymer particles are stably dispersed in an organic solvent A.

  As the resin of the dispersed phase, a styrene-maleic acid copolymer resin is used in the example of Patent Document 1, a styrene-maleic acid copolymer resin and polyvinylpyrrolidone are used in the example of Patent Document 2, and in Non-Patent Document 1, Polyvinyl pyrrolidone is used. These resins are resins having a negatively dissociating polar group or resins having a positively dissociating polar group, and form a polymer particle having a negative charge or a positive charge to provide a stable dispersion. It has been proposed to be.

  In Patent Document 3, an organic solvent A and an organic solvent B that is hardly compatible with the organic solvent A are used, and a dispersed phase containing the organic solvent B and a polyfunctional monomer or resin and a polymerization initiator and the organic solvent A are used. A polymer in which polymer particles are dispersed in the organic solvent A by forming a dispersion liquid comprising a continuous phase and then causing a crosslinking reaction by light or heat and removing the organic solvent B from the dispersion liquid by reducing pressure or heating. It has been proposed to produce particle dispersions.

  According to the above documents, polymer particle dispersions are used as coloring materials for inks, copying toners, paints for various uses, liquid crystals to be colored, color filters for portable terminals, electronic books and electronic papers. It is desired that high-level to micro-level polymer particles are stably dispersed.

  However, when the printing ink is prepared using these polymer particle dispersions, the water resistance, marker resistance and scratch resistance of an ink image printed on paper or the like have not been studied in the above literature. When a resin that improves the water resistance, marker resistance, and scratch resistance of the ink is used as the resin of the dispersed phase in the above document, it is difficult to maintain the stability of the dispersion.

  In addition, the method of Patent Document 3 requires a polymerization reaction of a polyfunctional monomer or resin in the dispersed phase, and there is a problem that the number of production steps of the polymer particle dispersion is increased.

JP 2007-197632 A JP 2005-255911 A JP 2007-197633 A

Polymer Papers, Vol. 62, no. 7, pp. 310-315 (Jury, 2005)

  An object of the present invention is to provide a colored resin particle dispersion and an ink that are excellent in marker resistance and scratch resistance as well as water resistance.

  According to one aspect of the present invention, using a non-aqueous solvent A and a non-aqueous solvent B having a solubility in the non-aqueous solvent A of 3 g / 100 g or less at 23 ° C. and having a boiling point lower than that of the non-aqueous solvent A, An oil-in-oil emulsion is prepared by dispersing a dispersed phase containing the non-aqueous solvent B, a dye, a resin, and an acidic dispersant in a continuous phase containing the non-aqueous solvent A and a basic dispersant. The non-aqueous solvent B is removed from the mold emulsion by reducing pressure and / or heating, the basic dispersant has higher solubility in the non-aqueous solvent A than the non-aqueous solvent B, and the resin is A colored resin particle dispersion having a higher solubility in the non-aqueous solvent B than the non-aqueous solvent A is provided.

  According to another aspect of the present invention, an ink including the colored resin particle dispersion is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the colored resin particle dispersion and ink which are excellent in marker resistance and abrasion resistance with water resistance can be provided.

  The colored resin particle dispersion (hereinafter sometimes simply referred to as “dispersion”) according to an embodiment of the present invention includes a non-aqueous solvent A (hereinafter sometimes simply referred to as “solvent A”) and a non-aqueous solvent A. Non-aqueous solvent A and basic dispersion using non-aqueous solvent B (hereinafter sometimes referred to simply as “solvent B”) having a solubility in water of 3 g / 100 g or less at 23 ° C. and a boiling point lower than that of non-aqueous solvent A An oil-in-oil emulsion is prepared by dispersing a dispersed phase containing a non-aqueous solvent B, a dye, a resin, and an acidic dispersant in a continuous phase containing an agent. The aqueous solvent B is removed, the basic dispersant has higher solubility in the non-aqueous solvent A than the non-aqueous solvent B, and the resin has higher solubility in the non-aqueous solvent B than the non-aqueous solvent A. Features.

  As a result, it is possible to provide an ink that is excellent in water resistance as well as marker resistance and scratch resistance.

  According to the present embodiment, by including an acidic dispersant in the dispersed phase, an oil-in-oil emulsion can be adjusted with excellent emulsification stability regardless of the type of resin, particularly with water resistance. Even when a resin excellent in marker resistance and scratch resistance is used, an oil-in-oil emulsion having excellent emulsification stability can be provided. Thereby, it is possible to provide a colored resin particle dispersion excellent in marker resistance and scratch resistance as well as water resistance, and to provide an ink containing the same.

  In the dispersion according to the present embodiment, the continuous phase and the dispersed phase are mixed to produce an oil-in-oil (O / O) emulsion, and the solvent B is removed from the dispersed phase by reducing pressure and / or heating. can get.

  The continuous phase contains solvent A and a basic dispersant.

  The solvent A can be appropriately selected from various non-aqueous solvents so as to satisfy the relationship with the basic dispersant, the solvent B, and the resin described later.

  Here, the non-aqueous solvent refers to a non-polar organic solvent and a polar organic solvent having a 50% distillation point of 100 ° C. or higher (the same applies hereinafter). The 50% distillation point means a temperature at which 50% by mass of a solvent is volatilized, which is measured according to JIS K0066 “Testing method for distillation of chemical products”.

  Preferred examples of the nonpolar organic solvent include aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, and aromatic hydrocarbon solvents. Examples of the aliphatic hydrocarbon solvent and alicyclic hydrocarbon solvent include petroleum hydrocarbon solvents such as naphthene, paraffin and isoparaffin, and commercially available products include JX Nippon Oil & Energy Corporation. Made by company "Teklin N-16, Teklin N-20, Teklin N-22, Nisseki Naphthezol L, Nisseki Naphthezol M, Nisseki Naphthezol H, No. 0 Solvent L, No. 0 Solvent M, No. 0 Solvent H, Nisseki ISOZOL 300, Nisseki ISOZOL 400, AF-4, AF-5, AF-6, AF-7 ”,“ Isopar E, Isopar G, Isopar H, Isopar L, Isopar M, Exxol DSP100, manufactured by ExxonMobil Corporation / 140, Exxsol D30, Exxsol D40, Exxs l D80, Exxsol D100, Exxsol D130, Exxsol D140 ", Japan Sun Oil Co., Ltd." war, there can be mentioned preferably a Thumper ", and the like. Preferable examples of the aromatic hydrocarbon solvent include “Nisseki Cleansol G” (alkylbenzene) manufactured by JX Nippon Oil & Energy Corporation, “Solvesso 200” manufactured by Exxon Mobile, and the like.

  As the polar organic solvent, ester solvents, alcohol solvents, higher fatty acid solvents, ether solvents, and mixed solvents thereof can be used. For example, selected from the group consisting of an ester solvent that is an ester of a higher fatty acid having 8 to 20 carbon atoms and an alcohol having 1 to 24 carbon atoms, a higher alcohol having 8 to 24 carbon atoms, and a higher fatty acid having 8 to 20 carbon atoms. One or more of these can be used.

More specifically, as polar organic solvents, methyl laurate, isopropyl laurate, isopropyl myristate, isopropyl palmitate, isostearyl palmitate, isooctyl palmitate, methyl oleate, ethyl oleate, isopropyl oleate, butyl oleate , Methyl linoleate, isobutyl linoleate, ethyl linoleate, isopropyl isostearate, soybean oil methyl, soybean oil isobutyl, tall oil methyl, tall oil isobutyl, diisopropyl adipate, diisopropyl sebacate, diethyl sebacate, propylene glycol monocaprate Ester solvents such as trimethylolpropane tri-2-ethylhexanoate and glyceryl tri-2-ethylhexanoate; isomyristyl alcohol, isopalmityl Higher alcohol solvents such as alcohol, isostearyl alcohol, oleyl alcohol, hexyl decanol, octyldodecanol, and decitetradecanol; Preferred examples include higher fatty acid solvents; ether solvents such as diethyl glycol monobutyl ether, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, and propylene glycol dibutyl ether.
These can be used alone or in combination of two or more.

  Among these, the solvent A is preferably a nonpolar organic solvent, and more preferably a naphthenic, paraffinic, or isoparaffinic hydrocarbon solvent.

The solubility parameter of the solvent A is preferably 8.5 (cal / cm ³ ) ^1/2 or less, and more preferably 8.0 (cal / cm ³ ) ^1/2 or less.

  The boiling point of the solvent A is preferably 400 ° C. or lower, more preferably 300 ° C. or lower. On the other hand, the lower limit of the boiling point of the solvent A is preferably 90 ° C. or higher, and more preferably 150 ° C. or higher, in order to prevent volatilization of the solvent A and maintain the stability of the colored resin particle dispersion. .

  The basic dispersant is a dispersant having a basic functional group. The basic dispersant is not particularly limited as long as the solubility in the solvent A is higher than that in the solvent B.

  Preferably, the basic dispersant has a solubility in the solvent B of 3 g / 100 g or less at 23 ° C., more preferably 0.5 g / 100 g or less. Preferably, the basic dispersant has a solubility in the solvent A of 3 g / 100 g or more at 23 ° C., more preferably 5 g / 100 g or more. More preferably, the basic dispersant is used so that the basic dispersant is substantially completely dissolved in the solvent A and the basic dispersant is not substantially dissolved in the solvent B at the mixing ratio of the water-in-oil emulsion. Selected.

  Examples of the basic functional group of the basic dispersant include an amino group and a pyridyl group. Among them, an amino group is preferable.

  Examples of the basic dispersant include basic group-modified polyurethane, basic group-modified poly (meth) acrylate, basic group-modified polyester, polyesteramine, quaternary ammonium salt, alkylamine salt such as stearylamine acetate, fatty acid, and the like. An amine salt etc. can be mentioned. You may use these individually or in combination of multiple types.

As a basic dispersing agent, as a commercially available thing, for example,
“13940 (polyesteramine type), 17000, 18000 (fatty acid amine type), 11200, 22000, 24000, 28000” (all trade names) manufactured by Nippon Lubrizol Co., Ltd.
"DISPERKBYK116, 2096, 2163" (all trade names) manufactured by Big Chemie Japan,
“Acetamine 24, 86 (alkylamine salt type)” (both trade names) manufactured by Kao Corporation,
“Disparon KS-860, KS-873N4 (amine salt of polymer polyester)” (both are trade names) manufactured by Enomoto Kasei Co., Ltd. can be used.

  As content of a basic dispersing agent, it is preferable that it is 0.1-10 mass% with respect to the whole colored resin particle dispersion, More preferably, it is 1-5 mass%.

  To the continuous phase, other optional components such as an antioxidant, a surface tension adjusting agent, and an antifoaming agent may be added as long as the effects of the present invention are not impaired.

  The dispersed phase includes solvent B, dye, resin, and acidic dispersant.

  The solvent B has a solubility in the above-described solvent A of 3 g / 100 g or less at 23 ° C. and a boiling point lower than that of the solvent A.

  The solvent B can be appropriately selected from non-aqueous solvents and is preferably a polar organic solvent, more preferably a lower alcohol solvent. Examples of the lower alcohol solvent include isopropyl alcohol, ethylene glycol, glycerin, ethanol, methanol, propanol, and butanol. More preferably, it is a lower alcohol solvent having 4 or less carbon atoms.

Other specific examples of the solvent B include acetone, methyl ethyl ketone, ethyl acetate, and the like. Further, among the specific examples of the solvent A, the relationship between the solvent A, the basic dispersant, and the resin is as follows. Those satisfying can be appropriately selected and used.
These can be used alone or in combination of two or more.

  The solubility of solvent B in solvent A is 3 g / 100 g at 23 ° C., more preferably 1 g / 100 g or less at 23 ° C., further preferably 0.5 g / 100 g or less, more preferably substantially It does not dissolve in.

  The difference in boiling point between the solvent B and the solvent A is preferably 10 ° C. or higher, more preferably 20 ° C. or higher. Moreover, it is preferable that the boiling point of the solvent B is 100 degrees C or less, More preferably, it is 90 degrees C or less. On the other hand, the lower limit of the boiling point of the solvent B is not particularly limited as long as the solvent B is liquid in the range of −20 to 90 ° C.

The solubility parameter of the solvent B is preferably 9 (cal / cm ³ ) ^1/2 or more, and more preferably 10 (cal / cm ³ ) ^1/2 or more.

  Moreover, it is preferable that the solvent A is a hydrocarbon solvent and the solvent B is an alcohol solvent having 4 or less carbon atoms. Preferable examples of the hydrocarbon solvent include paraffin and isoparaffin, and preferable examples of the alcohol solvent having 4 or more carbon atoms include methanol, ethanol, propanol, butanol, and more preferably methanol.

  As the dye, those generally used in the technical field can be arbitrarily used. For example, basic dye, acid dye, direct dye, soluble vat dye, acid mordant dye, mordant dye, reactive dye, vat Examples thereof include dyes, sulfur dyes and metal complex dyes. You may use these individually or in combination of multiple types.

  Preferably, the dye has higher solubility in the solvent B than in the solvent A, so that the resin is dissolved in the solvent B together with the dye in the dispersed phase, so that the colored resin particle dispersion can be stably provided.

  Here, the solubility of the dye in the solvent A is preferably 0.5 g / 100 g or less at 23 ° C., more preferably 0.1 g / 100 g or less. The dye has a solubility in the solvent B of preferably 0.5 g / 100 g or more at 23 ° C., more preferably 1 g / 100 g or more. More preferably, the dye is selected so that substantially all of the dye is dissolved in the solvent B and the dye is not substantially dissolved in the solvent A in the mixing ratio of the water-in-oil emulsion.

  The dye is preferably an oil-soluble dye that is soluble in the resin in the dispersed phase. Moreover, by using an acidic dye, a basic dispersant is contained in the continuous phase and an acidic acidic dye is contained in the dispersed phase, so that the oil-in-oil emulsion can be further stabilized. More preferred are metal complex dyes.

  Examples of such oil-soluble dyes include “OIL COLORS series” and “VALIFAST COLORS series” manufactured by Orient Chemical Industries, Ltd.

  The content of the dye is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass, and still more preferably 2 to 20% by mass with respect to the entire colored resin particle dispersion. .

  As the resin, the solubility in the solvent B is higher than that in the solvent A.

  The solubility of the resin in the solvent B is preferably 10 g / 100 g or more at 23 ° C., more preferably 20 g / 100 g or more. Moreover, it is preferable that the solubility with respect to the solvent A of resin is 3 g / 100g or less at 23 degreeC, More preferably, it is 0.5 g / 100g or less. More preferably, the resin is one that substantially dissolves in the solvent B and does not substantially dissolve in the solvent A in the blending ratio of the oil-in-oil emulsion.

  Examples of the resin include polyvinyl alcohol (PVA), rosin resin, rosin-modified resin, styrene-maleic anhydride resin and its ester, alkylphenol resin, ketone resin, alcohol-soluble polyamide resin, butyral resin, vinyl acetate resin, and the like. be able to. These can be used alone or in combination of two or more. Of these, polyvinyl alcohol is preferred.

  Of the resins that can be used, the saponification degree of polyvinyl alcohol is preferably 60 mol% or less, more preferably 40 mol% or less, and even more preferably 10 mol% or less. When the saponification degree is 60 mol% or less, the solubility in the solvent B increases.

  The resin preferably has a solubility in water of 3 g / 100 g or less at 23 ° C., more preferably 0.5 g / 100 g or less, and still more preferably does not substantially dissolve. As a result, the water resistance of the resin itself is increased, so that the water resistance of the dispersion is also increased, and the water resistance of the printed image can be increased.

  As a weight average molecular weight of resin, 3000-100000 are preferable, More preferably, it is 5000-80000.

  As content of resin, it is preferable that it is 0.1-50 mass% with respect to the coloring resin particle dispersion whole quantity, More preferably, it is 1-40 mass%, More preferably, it is 2-20 mass%. .

  The acidic dispersant is a dispersant having an acidic functional group. By adding an acidic dispersant, the scratch resistance can be further improved. This is because, when imparting water resistance to a resin in the dispersed phase using a resin having a low acid value, the scratch resistance may be reduced, but by adding an acidic dispersant together with this resin, the scratch resistance is reduced. Both can be improved.

  Moreover, the emulsification stability of the oil-in-oil type emulsion which consists of a continuous phase and a dispersed phase can be improved by adding an acidic dispersing agent to a dispersed phase.

  The acidic dispersant is not particularly limited, but preferably has higher solubility in the solvent B than the solvent A. The solubility of the acidic dispersant in the solvent B is preferably 1 g / 100 g or more at 23 ° C., more preferably 2 g / 100 g or more. Further, the solubility of the acidic dispersant in the solvent A is preferably 3 g / 100 g or less at 23 ° C., more preferably 0.5 g / 100 g or less. More preferably, the acidic dispersant is substantially completely dissolved in the solvent B and not substantially dissolved in the solvent A in the blending ratio of the oil-in-oil emulsion.

  The acidic dispersant preferably has an acid value. The acid value of the acidic dispersant is preferably 30 KOH mg / g or more, more preferably 60 KOH mg / g or more, and still more preferably 90 KOH mg / g or more.

  Here, the acid value is the number of milligrams of potassium hydroxide required to neutralize 1 g of the dispersant solid content. The same applies hereinafter.

  Examples of the acidic dispersant include a copolymer or copolymer having an acidic group, an alkyl ammonium salt such as an alkyl ammonium salt of a block copolymer having an acidic group, a hydroxyl group-containing carboxylic acid ester, a salt of a high molecular weight polycarboxylic acid, and the like. Fatty acid salt, polyether ester type anionic surfactant, naphthalenesulfonic acid formalin condensate salt, phosphoric acid ester such as polyoxyethylene alkyl phosphoric acid ester and its salt, alkyl sulfuric acid ester salt, polyoxyethylene alkyl ether sulfuric acid ester Examples thereof include salts and sulfonates such as alkylbenzene sulfonates. You may use these individually or in combination of multiple types.

  Among them, phosphate esters having an acid value of 90 KOH mg / g or more and / or alkyl ammonium salts having an acid value of 90 KOH mg / g or more are preferable.

Examples of commercially available acidic dispersants include:
"DISPERBYK102, 108, 110, 111, 180" (all trade names) manufactured by Big Chemie Japan,
Examples thereof include “TEGODisper655” manufactured by Sakai Kogyo Co., Ltd.

  As content of an acidic dispersing agent, it is preferable that it is 0.1-20 mass% with respect to the whole colored resin fine particle dispersion, More preferably, it is 1-15 mass%.

  The mass ratio between the acidic dispersant and the dye is preferably (acid dispersant mass) / (dye mass) ≧ 0.5. Within this range, when the continuous phase and the dispersed phase are mixed and stirred, an oil-in-oil emulsion excellent in emulsion stability can be provided.

  You may add other arbitrary components, such as an antifoamer, antioxidant, and a surface tension regulator, to a dispersed phase in the range which does not impair the effect of this invention.

  In the colored resin particle dispersion, the average particle diameter of the colored resin particles is preferably about 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. The average particle diameter of the colored resin particles may be appropriately adjusted according to the type of the recording medium. For example, in order to suppress the back-through of the printed material using the coated paper, the average particle diameter is about 150 nm. Is preferred. Here, the average particle diameter of the pigment composite is a value measured by a dynamic light scattering particle size distribution measuring apparatus “LB-500” manufactured by Horiba, Ltd.

  The average particle diameter of the colored resin particles can be controlled by adjusting the amount of the basic dispersant blended in the continuous phase or the solid content blended in the dispersed phase.

  The method for preparing the colored resin particle dispersion is not particularly limited, and an oil-in-oil emulsion is prepared by dispersing the above-described dispersed phase in the above-described continuous phase. From this oil-in-oil emulsion, the pressure is reduced and / or heated. It can be adjusted by removing the non-aqueous solvent B in the dispersed phase.

  For example, the continuous phase and the dispersed phase can be adjusted by mixing the above-described components. Thereafter, the dispersed phase can be dispersed in the continuous phase by mixing and stirring while dropping the dispersed phase in the continuous phase. At this time, mixing and stirring can be performed using an ultrasonic homogenizer. The non-aqueous solvent B is removed from the obtained oil-in-oil emulsion by reducing pressure and / or heating. At this time, the degree of pressure reduction and / or heating is adjusted so that the non-aqueous solvent B is removed, but the non-aqueous solvent A remains.

  Moreover, the mass ratio of the continuous phase and the dispersed phase of the oil-in-oil emulsion can be adjusted in the range of 40:60 to 95: 5. The addition amount of the non-aqueous solvent B is preferably 5 to 40% by mass, more preferably 5 to 30% by mass with respect to the whole oil-in-oil emulsion. The removal amount of the non-aqueous solvent B is desirably the total amount of the non-aqueous solvent B blended, but may be 90% by mass or more with respect to the total amount of the non-aqueous solvent B blended.

  The ink according to this embodiment is an ink containing the above-described colored resin particle dispersion. This ink can be used as a general printing ink such as inkjet printing, offset printing, stencil printing, and gravure printing. In particular, since the dispersion stability is good, it is preferably used as an inkjet ink.

  When used as an ink-jet ink, the colored resin particle dispersion can be used as it is, and if necessary, various additives usually used in the field within a range not impairing the object of the present invention. Can be included. For example, a nozzle clogging preventive agent, an antioxidant, a conductivity adjusting agent, a viscosity adjusting agent, a surface tension adjusting agent, an oxygen absorbent and the like can be added as appropriate. These types are not particularly limited, and those used in the field can be used. Further, the colored resin particle dispersion may be diluted with the non-aqueous solvent described above.

  The viscosity of the inkjet ink varies depending on the nozzle diameter of the ejection head of the inkjet recording system, the ejection environment, and the like, but in general, the viscosity is preferably 5 to 30 mPa · s at 23 ° C., preferably 5 to 15 mPa · s. More preferably, it is about 10 mPa · s. Here, the viscosity represents a value at 10 Pa when the shear stress is increased from 0 Pa at a rate of 0.1 Pa / s at 23 ° C.

  The printing method using the inkjet ink is not particularly limited, and any method such as a piezo method, an electrostatic method, or a thermal method may be used. When an ink jet recording apparatus is used, it is preferable that the ink according to the present embodiment is ejected from the ink jet head based on a digital signal, and the ejected ink droplets are attached to the recording medium.

  The recording medium is not particularly limited, and plain paper, glossy paper, special paper, cloth, film, OHP sheet, and the like can be used.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

<Ink adjustment>
Tables 1 to 3 show the formulations of the oil-in-oil emulsions of Examples and Comparative Examples before removing the solvent B. In each table, the unit of the acid value of the dispersant is “KOHmg / g”. When the volatile component is contained in the dispersant, the nonvolatile content is shown in parentheses together with the total amount of the dispersant (table to be described later). 4 to Table 6 are the same).

  A continuous phase was prepared by mixing the solvent A and the basic dispersant shown in each table in each compounding amount. Next, a dye, a resin, and an acidic dispersant were mixed with each solvent in the solvent B shown in each table to prepare a dispersed phase.

  While stirring the continuous phase with a magnetic stirrer, an ultrasonic homogenizer “Ultrasonic processor VC-750” (manufactured by Sonics) was irradiated for 10 minutes while adding a pre-mixed dispersed phase dropwise to the continuous phase. An oil-in-oil (O / O) emulsion was obtained.

  While the obtained emulsion was decompressed with an evaporator, the solvent B in the dispersed phase was removed to obtain a colored resin particle dispersion. The removal rate of the solvent B was almost 100% by mass. This colored fine particle dispersion was used as an ink as it was.

  Tables 4 to 6 show ink formulations of Examples and Comparative Examples after removal of the solvent B. The solid content is determined from the total amount of the solid content (basic dispersant, dye, resin, acidic dispersant, and comparative dispersant) relative to the total amount of ink, and is also shown in each table.

The components shown in each table are as follows.
(Continuous phase)
Basic dispersant: “Solsperse 17000” manufactured by Nippon Lubrizol Co., Ltd., 100% nonvolatile content
Hydrocarbon solvent: Isoparaffin hydrocarbon, “Isopar M” manufactured by Exxon Mobile

(Dispersed phase)
Methanol: C1-C1 alcohol solvent, manufactured by Wako Pure Chemical Industries, Ltd. Acidic dispersant 1: Phosphate ester of specially modified polyether polymer, “TEGODisper655” manufactured by Sakai Kogyo Co., Ltd., 100% non-volatile content
Acidic dispersant 2: copolymer having an acid group (phosphate ester), “DISPERBYK-111” manufactured by Big Chemie Japan, non-volatile content 95.0%
Acid Dispersant 3: Alkyl ammonium salt of block copolymer having acid group, “DISPERBYK-180” manufactured by Big Chemie Japan Co., Ltd., non-volatile content 81%,
Comparative dispersant 1: Nonionic dispersant, “DISPERBYK-192” manufactured by Big Chemie Japan, non-volatile content 98%
Comparative dispersant 2: Basic dispersant, “DISPERBYK-2155” manufactured by Big Chemie Japan, non-volatile content 99%
Black metal complex dye: “Valifast Black 3810” manufactured by Orient Chemical Co., Ltd.
Yellow metal complex dye: “Valifast Yellow 1101” manufactured by Orient Chemical Co., Ltd.
Polyvinyl alcohol: degree of saponification 2.7 mol%, weight average molecular weight 15000, “JMR-8L” manufactured by Nihon Acetate / Poval
Polyvinylpyrrolidone: weight average molecular weight 40000, “PVP K-30” manufactured by Wako Pure Chemical Industries, Ltd.
Styrene maleic acid resin: weight average molecular weight 7000, “SMA Resin 1440F” manufactured by Kawa Crude Oil Co., Ltd.

  Methanol as the solvent B has a solubility in a hydrocarbon solvent (Isopar M) as the solvent A of 0.4 g / 100 g at 23 ° C. The boiling point of methanol is 64.7 ° C., and the boiling point of Iopar M is approximately 222 ° C.

Solsperse 17000, which is a basic dispersant, was dissolved in the solvent A at the blending ratio of the continuous phases shown in Tables 1 to 3, and the solubility in the solvent B was less than 3 g / 100 g at 23 ° C.
Each of the dyes was dissolved in the solvent B at the mixing ratio of the dispersed phases shown in Tables 1 to 3, and the solubility in the solvent A was less than 0.5 g / 100 g at 23 ° C.
Each of the resins is dissolved in the solvent B at the mixing ratio of the dispersed phases shown in Tables 1 to 3, the solubility in the solvent A is less than 3 g / 100 g at 23 ° C., and the solubility in water is less than 3 g / 100 g at 23 ° C. Met.
The acidic dispersants 1 to 3 and the comparative dispersants 1 and 2 were dissolved in the solvent B at the mixing ratio of the dispersed phases shown in Tables 1 to 3, and the solubility in the solvent A was less than 3 g / 100 g at 23 ° C.

<Evaluation>
Using each of the inks described above, the scratch resistance, water resistance, marker resistance, and colored resin particle diameter were evaluated. The results are shown in each table.

(Abrasion resistance)
Each of the inks described above is loaded into a line-type ink jet printer “Orpheus HC5500” (made by Riso Kagaku Co., Ltd.), and a solid image is printed on coated paper “Aurora Coat” (made by Nippon Paper Industries Co., Ltd.) to obtain a printed matter. It was. Printing was performed at a resolution of 300 × 300 dpi under an ejection condition where the ink amount per dot was 42 pl. The “Orpheus HC5500” is a system that uses a line-type inkjet head and conveys paper in the sub-scanning direction orthogonal to the main scanning direction (the direction in which the nozzles are arranged) to perform printing.

After standing for 300 seconds after printing and after standing for 24 hours, the solid image portion of the printed material was observed by visual observation of the solid image when it was rubbed with a finger five times, and scratch resistance was evaluated according to the following criteria.
A: Level at which image peeling is hardly observed.
B: A level at which peeling of the image is confirmed but there is no problem in actual use.
C: Image peeling is remarkable and there is a problem in actual use.

(water resistant)
A printed matter was obtained in the same manner as the above-mentioned scratch resistance. After standing for 300 seconds after printing, 0.5 ml of water was dropped on the solid image portion of the printed matter, and the bleeding was visually observed to evaluate the water resistance according to the following criteria.
A: Level at which the printed image portion does not blur.
B: A level at which there is no problem in actual use although the printed image portion is slightly blurred.
C: The level where the printed image portion is blurred and there is a problem in actual use.

(Marker resistance)
A printed matter was obtained in the same manner as the above-mentioned scratch resistance. After leaving for 300 seconds after printing, draw a line on the characters on the coated paper printing part with the line marker pen “PM-L103Y” manufactured by KOKUYO Co., Ltd. evaluated.
A: A level in which the printed image portion is not stained or the periphery of the printed image portion is slightly stained.
B: A level at which there is no problem in actual use although the periphery of the printed image portion is dirty.
C: The area around the printed image is a level where there is a problem in actual use.

(Average particle diameter of colored resin particles)
For each of the inks described above, the average particle size of the colored resin particles dispersed in the ink was measured using a dynamic light scattering type particle size distribution measuring device “LB-500” (manufactured by Horiba, Ltd.). Calculated from

  As shown in the above tables, the ink of each example had good scratch resistance, water resistance and marker resistance, and the average particle diameter of the colored resin particles was in an appropriate range.

  In Comparative Examples 1 and 2, polyvinyl pyrrolidone was used as the resin and the dispersion phase did not contain a dispersant, and good results were not obtained. In Comparative Examples 3 and 4, a nonionic dispersant and a basic dispersant were used as Comparative Dispersants 1 and 2, respectively, and each component could not be emulsified and an ink could not be prepared. In Comparative Examples 5 and 6, polyvinyl alcohol was used as the resin, and no dispersant was contained in the dispersed phase, and good results were not obtained.

Claims (8)

Using a non-aqueous solvent A and a non-aqueous solvent B having a solubility in the non-aqueous solvent A of 3 g / 100 g or less at 23 ° C. and having a boiling point lower than that of the non-aqueous solvent A,
In a continuous phase containing the non-aqueous solvent A and a basic dispersant, a dispersed phase containing the non-aqueous solvent B, a dye, a resin, and an acidic dispersant is dispersed to prepare an oil-in-oil emulsion,
From the oil-in-oil emulsion, the non-aqueous solvent B is removed by reduced pressure and / or heating,
The basic dispersant has higher solubility in the non-aqueous solvent A than the non-aqueous solvent B,
The resin has higher solubility in the non-aqueous solvent B than the non-aqueous solvent A.
Colored resin particle dispersion.   2. The colored resin particle dispersion according to claim 1, wherein the acidic dispersant is a phosphate ester or a salt thereof having an acid value of 90 KOH mg / g or more and / or an alkyl ammonium salt having an acid value of 90 KOH mg / g or more. .   The colored resin particle dispersion according to claim 1, wherein the dye has higher solubility in the non-aqueous solvent B than in the non-aqueous solvent A.   The colored resin particle dispersion according to claim 3, wherein the dye is a metal complex dye.   The colored resin particle dispersion according to any one of claims 1 to 4, wherein the resin has a solubility in water of 3 g / 100 g or less at 23 ° C.   The colored resin particle dispersion according to any one of claims 1 to 5, wherein the resin is polyvinyl alcohol having a saponification degree of 60 mol% or less.   The colored resin particle dispersion according to any one of claims 1 to 6, wherein the non-aqueous solvent A is a hydrocarbon solvent and the non-aqueous solvent B is an alcohol solvent having 4 or less carbon atoms.   An ink comprising the colored resin particle dispersion according to any one of claims 1 to 7.