JP2005036220A - Nonaqueous-solvent-based pigment dispersant, inkjet ink composition, and liquid electrophotographic developer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonaqueous-solvent-based pigment dispersant which is applicable to various pigments without any limitation, can well disperse a colorant coated with a fixing resin in a nonaqueous solvent, and is easily producible, to provide an inkjet ink composition using the same, and to provide a liquid electrophotographic developer using the same. <P>SOLUTION: The nonaqueous-solvent-based pigment dispersion comprises a silicone graft copolymer and is soluble in a nonaqueous solvent. The silicone graft copolymer comprises a monomer which constitutes a main chain part insoluble in the nonaqueous solvent and a monomer which constitutes a graft part soluble in the nonaqueous solvent. The monomer which constitutes the graft part contains a silicone macromonomer (M) having a polymerizable functional group at one terminal. The inkjet ink composition and the liquid electrophotographic developer are prepared by using the same. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a non-aqueous solvent-based pigment dispersant, an ink-jet ink composition, and an electrophotographic liquid developer. More specifically, the present invention can be applied to various pigments without limitation and is coated with a fixing resin. The colorant can be well dispersed in a non-aqueous solvent, and includes a non-aqueous solvent-based pigment dispersant that is easy to manufacture, and includes the non-aqueous solvent-based pigment dispersant, and has high ejection stability, and can be used on recording paper. Ink-jet ink composition with excellent dryness, water resistance and light resistance of recorded images, and high scratch resistance, as well as excellent dispersion stability and scratch resistance, as well as charge polarity control and stable charge over time The present invention relates to a liquid developer for electrophotography having excellent properties.

  In general, a practically useful pigment that exhibits a clear color tone and high coloring power in a liquid developer for electrostatic photography, an oil-based ink for inkjet, various coatings, or an ink composition is composed of fine particles. When fine particles of pigment are dispersed in non-aqueous solvents such as liquid developers, inkjet oil-based inks, offset inks, gravure inks, and paints, it is difficult to obtain a stable dispersion. Is used to improve the affinity between the pigment and the non-aqueous solvent and stabilize the dispersion. As such pigment dispersants, nonionic, anionic and cationic surfactants, pigment derivatives, and polymeric pigment dispersants are well known.

  Any pigment dispersant for dispersing the pigment in the non-polar non-aqueous solvent may be used as long as it is compatible with the solvent or can stably disperse the fine particles. For example, it is disclosed in JP-A-5-25414. In general, surfactants are often used. Specific examples thereof include sorbitan fatty acid esters (sorbitan monooleate, sorbitan monolaurate, sorbitan sesquioleate, sorbitan trioleate, etc.), polyoxyethylene sorbitan fatty acid esters (polyoxyethylene sorbitan monostearate, polyoxyethylene). Sorbitan monooleate), polyethylene glycol fatty acid ester (polyoxyethylene monostearate, polyethylene bricol diisostearate, etc.), polyoxyethylene alkyl phenyl ether (polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, etc.) ). In addition, an anionic active agent, a cationic active agent, or a nonionic active agent is also used. However, these surfactants do not allow fine dispersion of the pigment in a nonpolar solvent, and there is room for improvement in the dispersion stability of the dispersion.

  Examples of the pigment derivative include, as represented by Japanese Patent Publication No. 41-2466 and U.S. Pat. No. 2,855,403, a sulfonic acid, a sulfonamide group, an aminomethyl group, phthalimidomethyl as a side chain with an organic pigment as a skeleton. Although a method of mixing a compound obtained by introducing a substituent such as a group is known, these compounds have a large effect on the non-aggregation property of the pigment, but the added compound has the same chemical structure as the pigment. Since it is derived from a compound having an intrinsic strong coloring, it is subject to significant restrictions when used in pigments of different hues. Therefore, it is necessary to prepare a corresponding compound for each individual pigment, which is extremely disadvantageous in the production of the pigment composition. In addition, when introducing a substituent into the side chain of these compounds, it is necessary to dissolve the pigment in concentrated sulfuric acid, fuming sulfuric acid or the like, or to react a chlorosulfonic acid or the like to introduce a reactive group into the pigment. Concentrated sulfuric acid, fuming sulfuric acid, and the like are dangerous and very difficult to handle, and are therefore very disadvantageous in production due to restrictions on production facilities and production volume.

  Examples of the polymer pigment dispersant include polymer compounds having a molecular weight of 1000 or more. For example, styrene-maleic acid resin, styrene-acrylic resin, rosin, BYK-160, 162, 164, 182 (manufactured by Big Chemie) Urethane polymer compound), EFKA-401, 402 (acrylic dispersant manufactured by EFKA), Solsperse 17000, 24000 (polyester polymer compound manufactured by Zeneca), and the like. However, these also do not provide effective dispersibility in nonpolar insulating solvents, especially when pigments coated with fixing resins are dispersed in nonpolar insulating solvents. In addition, in actual use, it is often used in combination with pigment derivatives having the above disadvantages.

Furthermore, when a silicone-based organic solvent is used as the non-aqueous solvent, there is no suitable dispersing agent for finely dispersing the pigment and the pigment coated with the resin, and since the dispersed particle size of the pigment is large, the ink is used for a long time. If stored, it will settle and the print quality will deteriorate.
JP-A-3-188469 discloses the use of a graft copolymer made of a macromonomer as such a non-aqueous solvent-based pigment dispersant. In JP-A-3-188469, for example, a copolymer obtained by dispersing a pigment coated with a fixing resin in a non-aqueous solvent using a graft copolymer obtained by copolymerizing styrene and a stearyl methacrylate macromonomer. However, there is no mention of a graft copolymer composed of a silicone-based macromonomer.

On the other hand, the use of a silicone-based graft polymer in an inkjet ink is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2001-342388) and Patent Document 2 (Japanese Patent Laid-Open No. 2002-105379). In Patent Documents 1 and 2, the self-dispersing silicone-based graft polymer and the pigment are dispersed in a good solvent for the graft polymer and then mixed with the poor solvent, and the graft polymer is adsorbed on the surface of the pigment and coated. is there. However, these patent documents make no mention of the use of a silicone-based graft polymer as a pigment dispersant and the dispersion effect of a resin-coated pigment.
JP 2001-342388 A JP 2002-105379 A

Therefore, the first object of the present invention can be applied to various pigments without limitation, and the colorant coated with the fixing resin can be well dispersed in a non-aqueous solvent and is easy to manufacture. It is to provide an aqueous solvent pigment dispersant.
A second object of the present invention is to provide an inkjet ink composition having a high discharge stability in which pigments are uniformly dispersed in fine particles, excellent in dispersion stability of the pigment, and hardly clogged at the nozzle portion. is there.
The third object of the present invention is to provide a printed matter with a high quality and clear color image that has excellent drying characteristics on recording paper, water resistance and light resistance of the recorded image, and high scratch resistance, and has no ink bleeding. To provide an ink-jet ink composition capable of printing a large number of sheets.
The fourth object of the present invention is excellent in dispersion stability and scratch resistance, excellent in control of charge polarity and stability over time of charge, and printed on a large number of high-quality and clear color images without ink bleeding. It is to provide a possible electrophotographic liquid developer.

As a result of intensive studies, the present inventors have found that the above-described problem can be solved by the following configuration. That is, the present invention is as follows.
(1) In a non-aqueous solvent-based pigment dispersant made of a silicone-based graft copolymer and soluble in a non-aqueous solvent, the silicone-based graft copolymer constitutes a main chain portion that is insoluble in the non-aqueous solvent. Non-water containing a monomer and a monomer constituting a graft portion soluble in a non-aqueous solvent, wherein the monomer constituting the graft portion contains a silicone-based macromonomer (M) having a polymerizable group at the terminal Solvent-based pigment dispersant.

(2) The polymerizable double monomer represented by the following general formula (I) is formed at the terminal of the main chain of the silicone polymer comprising the repeating unit represented by the following general formula (II). The non-aqueous solvent pigment dispersant according to the above (1), which is a macromonomer having a number average molecular weight of 1 × 10 ³ to 4 × 10 ^{4 formed} by bonding a bonding group.

In the general formula (I), V is _{-COO -, - COO (CH 2} ) m -, -OCO -, - OCO (CH 2) m -, - (CH 2) k -OCO -, - (CH 2) _k —COO—, —O—, —CONHCOO—, —CONHCO—, —CONH (CH ₂ ) _m —, —SO ₂ —, —CO—, —CONZ ¹ —, —SO ₂ NZ ¹ — or a phenylene group. To express. Here, Z ¹ represents a hydrogen atom or a hydrocarbon group, m represents an integer of 1 to 10, k is an integer of 1-3. a ¹ and a ^2, which may be the same or different, each represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a -COO-Z ³ via -COO-Z ³ or a hydrocarbon group. Z ³ represents a hydrogen atom or an optionally substituted hydrocarbon group.

In the general formula (II), X ⁰ is -COO -, - OCO -, - (CH 2) k -OCO -, - (CH 2) k -COO -, - O -, - CONHCOO -, - CONHCO, - It represents one or more linking groups selected from SO ₂ —, —CO—, —CONZ ² —, and SO ₂ NZ ² —. Here, Z ² represents a hydrogen atom or a hydrocarbon group, and b ¹ and b ² may be the same as or different from each other, and represent the same contents as a ¹ and a ² in the general formula (I). k represents an integer of 1 to 3. Q ⁰ represents an aliphatic group having 1 to 22 carbon atoms having a silicon atom-containing substituent.

(3) The non-aqueous solvent pigment according to claim 1, wherein the silicone-based macromonomer (M) is a macromonomer having a number average molecular weight of 1 × 10 ³ to 4 × 10 ⁴ represented by the following general formula (V). Dispersant.

In the general formula (V), V is _{-COO -, - COO (CH 2} ) m -, -OCO -, - OCO (CH 2) m -, - (CH 2) k -OCO -, - (CH 2) _k —COO—, —O—, —CONHCOO—, —CONHCO—, —CONH (CH ₂ ) _m —, —SO ₂ —, —CO—, —CONZ ¹ —, —SO ₂ NZ ¹ — or a phenylene group. To express. Here, Z ¹ represents a hydrogen atom or a hydrocarbon group, m represents an integer of 1 to 10, k is an integer of 1-3. a ¹ and a ^2, which may be the same or different, each represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a -COO-Z ³ via -COO-Z ³ or a hydrocarbon group. Z ³ represents a hydrogen atom or an optionally substituted hydrocarbon group. W ¹ is a single bond, or —C (Z ⁶ ) (Z ⁷ ) — [Z ⁶ and Z ⁷ are each a hydrogen atom, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group or a hydroxyl group. shown], - (CH = CH) - , a cyclohexylene group, -Ph -, - O -, - S -, - C (= O) -, - N (Z 8) -, - COO -, - SO 2 —, —CON (Z ⁸ ) —, —SO ₂ N (Z ⁸ ) —, —NHCOO—, —NHCONH— or —Si (Z ⁸ ) (Z ⁹ ) — [Z ⁸ , Z ⁹ is a hydrogen atom or Represents a hydrocarbon group having the same contents as Z ¹ ], and represents a single linking group selected from an atomic group such as linking group or any combination thereof. R ^{1 to} R ⁷ each independently represents an alkyl group having 1 to 10 carbon atoms, a phenyl group, or an aralkyl group having 7 to 16 carbon atoms.

(4) Aliphatic saturated carbonization in which the non-aqueous solvent has a viscosity of 3 cSt or less, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 22.5 to 28.0 mN / m (at 25 ° C.). The non-aqueous solvent pigment dispersant according to any one of (1) to (3), which is hydrogen.

(5) The above-mentioned non-aqueous solvent is a silicone oil having a viscosity of 0.5 to 20 cSt, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 15 to 21 mN / m (at 25 ° C.). The non-aqueous solvent pigment dispersant according to any one of (1) to (3).

(6) In an inkjet ink composition comprising a non-aqueous solvent and at least a colorant, a resin insoluble or swellable in the non-aqueous solvent, and a pigment dispersant, the pigment dispersant is The inkjet ink composition which is a non-aqueous solvent pigment dispersant according to any one of (1) to (3).
(7) In an inkjet ink composition comprising at least a colorant, a resin insoluble or swellable in the nonaqueous solvent, and a pigment dispersant in a nonaqueous solvent, the nonaqueous solvent comprises: An ink-jet ink composition, which is an aliphatic saturated hydrocarbon having a viscosity of 3 cSt or less, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 22.5 to 28.0 mN / m (at 25 ° C.).
(8) In an inkjet ink composition comprising at least a colorant, a resin that is insoluble or swellable in the nonaqueous solvent, and a pigment dispersant in a nonaqueous solvent, the nonaqueous solvent comprises: An ink-jet ink composition, which is a silicone oil having a viscosity of 0.5 to 20 cSt, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 15 to 21 mN / m (at 25 ° C.).

(9) In a liquid developer for electrophotography, which comprises, in a non-aqueous solvent, at least a colorant, a resin insoluble or swellable in the non-aqueous solvent, a pigment dispersant, and a charge control agent. An electrophotographic liquid developer, wherein the pigment dispersant is the non-aqueous solvent pigment dispersant according to any one of (1) to (3).
(10) In an electrophotographic liquid developer comprising a non-aqueous solvent and at least a colorant, a resin insoluble or swellable in the non-aqueous solvent, a pigment dispersant, and a charge control agent. The non-aqueous solvent is an aliphatic saturated hydrocarbon having a viscosity of 3 cSt or less, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 22.5 to 28.0 mN / m (at 25 ° C.). Liquid developer for electrophotography.
(11) In a liquid developer for electrophotography, which comprises, in a non-aqueous solvent, at least a colorant, a resin insoluble or swellable in the non-aqueous solvent, a pigment dispersant, and a charge control agent. The electrophotographic liquid in which the non-aqueous solvent is a silicone oil having a viscosity of 0.5 to 20 cSt, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 15 to 21 mN / m (at 25 ° C.). Developer.

According to the present invention, a non-aqueous solvent-based pigment dispersion that can be applied to various pigments without limitation, and that a colorant coated with a fixing resin can be favorably dispersed in a non-aqueous solvent and is easy to manufacture. An agent is provided.
Further, according to the present invention, there is provided an ink-jet ink composition having a high discharge stability in which pigments are uniformly dispersed in fine particles, excellent in pigment dispersion stability, and hardly clogged at the nozzle portion.
Further, according to the present invention, a large number of prints of high-quality and clear color images having excellent drying characteristics on recording paper, water resistance and light resistance of recorded images, high scratch resistance, and no ink bleeding. A printable inkjet ink composition is provided.
Furthermore, according to the present invention, the dispersion stability and scratch resistance are excellent, the charge polarity control and the charge stability over time are excellent, and a large number of high-quality, clear color images can be printed without ink bleeding. An electrophotographic liquid developer is provided.

The present invention is described in detail below.
Non-aqueous solvents used in the present invention are preferably less toxic, less flammable, less odorous, linear or branched aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic carbonization. Examples thereof include solvents selected from hydrogen, petroleum naphtha, halogen substitution products thereof and the like. For example, hexane, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, Isopar E from Exxon, Isopar G, Isopar H, Isopar L, Saltol from Philippe Petroleum, IP Solvent from Idemitsu Petrochemical, Petroleum Naphtha Then, S. of Shell Petrochemical Co., Ltd. B. R. Solvents selected from Shellzol 70, Shellzol 71, Mobil Petroleum Begazole, and the like can be used alone or in combination.

Preferable hydrocarbon solvents include high-purity isoparaffinic hydrocarbons having a boiling point in the range of 150 to 350 ° C., and commercially available products such as Isopar G, H, L, M, and V (manufactured by Exxon Chemical Co., Ltd.) Name), Noper 12, 13, 15 (trade name), IP Solvent 1620, 2028 (trade name) manufactured by Idemitsu Petrochemical, Isosol 300,400 (trade name) manufactured by Nippon Petrochemical, Amsco OMS, Amsco 460 solvent ( Amsco; a brand name of Spirits). These products are highly saturated aliphatic saturated hydrocarbons, the viscosity at 25 ° C. is 3 cSt or less, the specific resistance is 10 ¹⁰ Ω · cm or more, and the surface tension at 25 ° C. is 22.5 to 28.0 mN / m. It is. In addition, it is characterized by low reactivity and stability, low toxicity, high safety, and low odor. The relative dielectric constant is 1.5-20.

Examples of halogen-substituted hydrocarbon solvents include fluorocarbon solvents such as perfluoroalkanes represented by C _n F _{2n + 2} such as C ₇ F ₁₆ and C ₈ F ₁₈ (“Fluorinert PF5080” manufactured by Sumitomo 3M). , "Fluorinert PF5070" (trade name), etc.), Fluorinated inert liquids (such as "Fluorinert FC series" (trade name) manufactured by Sumitomo 3M), Fluorocarbons ("Crytox GPL series" manufactured by DuPont Japan Limited) (product) name), etc.), CFCs (manufactured by Daikin Industries, Ltd. "HCFC-141b" (trade name), _{etc.), [F (CF 2)} 4 CH 2 CH 2 I], such as _{[F (CF 2) 6 I} ] Examples thereof include iodinated fluorocarbons (“I-1420”, “I-1600” (trade name), etc., manufactured by Daikin Fine Chemical Laboratory).

As the non-aqueous solvent used in the present invention, higher fatty acid esters and silicone oil can also be used. Specific examples of silicone oils include low-viscosity synthetic dimethylpolysiloxane, cyclic methylpolysiloxane, and the like, and commercially available products include KF96L (trade name), KF994 (trade name), Toray Dow Corning made by Shin-Etsu Silicone. -There is SH200 (trade name) made of silicone.
The silicone oil is not limited to these specific examples. These dimethylpolysiloxanes are available in a very wide viscosity range depending on the molecular weight, but it is preferable to use those in the range of 0.5 to 20 cSt. These dimethylpolysiloxanes, like isoparaffinic hydrocarbons, have a specific resistance of 10 ¹⁰ Ω · cm or more, and are characterized by high stability, high safety, and odorlessness. These dimethylpolysiloxanes are characterized by low surface tension and have a surface tension of 15 to 21 mN / m (25 ° C.).

  Solvents that can be used in combination with these organic solvents include alcohols (eg, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, fluorinated alcohol), ketones (eg, acetone, methyl ethyl ketone, cyclohexanone, etc.), carvone Acid esters (eg, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, etc.), ethers (eg, diethyl ether, dipropyl ether, tetrahydrofuran, dioxane, etc.) and halogenated hydrocarbons ( Examples thereof include methylene dichloride, chloroform, carbon tetrachloride, dichloroethane, methyl chloroform, and the like.

Next, the colorant used in the present invention will be described in detail. The colorant is not particularly limited, and all commercially available organic pigments and inorganic pigments, or those obtained by dispersing a pigment in an insoluble resin or the like using a pigment as a dispersion medium, or a resin on the pigment surface. A grafted product can be used. Moreover, what dye | stained the resin particle with dye can be used. Specific examples of organic pigments and inorganic pigments include, for example, C.I. I. Pigment Yellow 1 (Fast Yellow G etc.), C.I. I. Monoazo pigments such as CI Pigment Yellow 74; I. Pigment Yellow 12 (disaji yellow AAA, etc.), C.I. I. Disazo pigments such as CI Pigment Yellow 17; I. Non-benzidine azo pigments such as CI Pigment Yellow 180; I. An azo lake pigment such as C.I. Pigment Yellow 100 (eg Tartrazine Yellow Lake); I. Condensed azo pigments such as CI Pigment Yellow 95 (Condensed Azo Yellow GR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Yellow 115 (such as quinoline yellow lake); I. Basic dye lake pigments such as CI Pigment Yellow 18 (Thioflavin Lake, etc.), anthraquinone pigments such as Flavantron Yellow (Y-24), isoindolinone pigments such as Isoindolinone Yellow 3RLT (Y-110), and quinophthalone yellow Quinophthalone pigments such as (Y-138), isoindoline pigments such as isoindoline yellow (Y-139), C.I. I. Nitroso pigments such as CI Pigment Yellow 153 (nickel nitroso yellow, etc.); I. And metal complex salt azomethine pigments such as CI Pigment Yellow 117 (copper azomethine yellow, etc.).

  As a magenta color, C.I. I. Monoazo pigments such as CI Pigment Red 3 (Toluidine Red, etc.); I. Disazo pigments such as C.I. Pigment Red 38 (Pyrazolone Red B, etc.); I. Pigment Red 53: 1 (Lake Red C, etc.) and C.I. I. Azo lake pigments such as CI Pigment Red 57: 1 (Brilliant Carmine 6B); I. Condensed azo pigments such as CI Pigment Red 144 (condensed azo red BR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Red 174 (Phloxine B Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Red 81 (Rhodamine 6G ′ Lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Red 177 (eg, dianthraquinonyl red); I. Thioindigo pigments such as C.I. Pigment Red 88 (Thioindigo Bordeaux, etc.); I. Perinone pigments such as C.I. Pigment Red 194 (perinone red, etc.); I. Perylene pigments such as C.I. Pigment Red 149 (perylene scarlet, etc.); I. Quinacridone pigments such as C.I. Pigment Red 122 (quinacridone magenta, etc.); I. Isoindolinone pigments such as C.I. Pigment Red 180 (isoindolinone red 2BLT, etc.); I. And alizarin lake pigments such as CI Pigment Red 83 (Madder Lake, etc.).

  As a pigment exhibiting a cyan color, C.I. Disazo pigments such as CI Pigment Blue 25 (dianisidine blue, etc.); I. Phthalocyanine pigments such as C.I. Pigment Blue 15 (phthalocyanine blue, etc.); I. Acidic dye lake pigments such as C.I. Pigment Blue 24 (Peacock Blue Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Blue 1 (such as Viclotia Pure Blue BO Lake); I. Anthraquinone pigments such as C.I. Pigment Blue 60 (Indantron Blue, etc.); I. And alkali blue pigments such as CI Pigment Blue 18 (Alkali Blue V-5: 1).

  Examples of black pigments include organic pigments such as aniline black pigments such as BK-1 (aniline black), iron oxide pigments, and carbon black pigments such as furnace black, lamp black, acetylene black, and channel black. . Specific examples of the carbon black pigment include MA-8, MA-10, MA-11, MA-100, MA-220, # 25, # 40, # 260, # 2600, # 2700B, manufactured by Mitsubishi Chemical Corporation. # 3230B, CF-9, MA-100R, MA-200RB, Degussa Printex 75, 90, Cabot Monarch 800, 1100, and the like. Also, metal powder can be applied and used for color reproduction of gold, silver, copper and the like.

  In addition, a processed pigment in which pigment fine particles are dispersed in a rosin ester resin, vinyl chloride-vinyl acetate resin, or the like is commercially available and may be used. Specific examples of commercially available processed pigments include microlith pigments manufactured by Ciba Specialty Chemicals, and preferred examples of processed pigments include Microlith-T pigments in which the pigment is coated with a rosin ester resin.

  The concentration of the colorant in the ink composition of the present invention is preferably 0.5 to 20% by mass, particularly preferably 2 to 15% by mass, based on the total amount of the ink composition. When the concentration of the colorant is 0.5% by mass or more, a sufficient printing density is obtained, and when the concentration is 20% by mass or less, a favorable ink viscosity is maintained, and stable ink discharge can be performed.

  Next, the silicone-based graft copolymer that is a feature of the non-aqueous solvent pigment dispersant of the present invention will be described in detail. The silicone-based graft copolymer in the present invention contains a monomer constituting a main chain part insoluble in a non-aqueous solvent and a monomer constituting a graft part (side chain part) soluble in a non-aqueous solvent, The monomer constituting the part (side chain part) contains a silicone macromonomer (M) having a polymerizable functional group at the terminal.

Preferably, the silicone-based macromonomer (M) has a polymerizable double chain represented by the following general formula (I) at the terminal of the main chain of the silicone polymer composed of a repeating unit represented by the following general formula (II). It is a silicone-based macromonomer (M) having a number average molecular weight of 1 × 10 ³ to 4 × 10 ^{4 formed} by bonding linking groups.

In general formula (I), V represents —COO—, —COO (CH ₂ ) _m —, —OCO—, —OCO (CH ₂ ) _m —, — (CH ₂ ) _k —OCO—, — (CH ₂ ). _k —COO—, —O—, —CONHCOO—, —CONHCO—, —CONH (CH ₂ ) _m —, —SO ₂ —, —CO—, —CONZ ¹ —, —SO ₂ NZ ¹ — or a phenylene group Hereinafter, a phenylene group is represented by Ph, where Ph represents 1,2-; 1,3-; 1,4-phenylene group). Here, Z ¹ represents a hydrogen atom or a hydrocarbon group, m represents an integer of 1 to 10, k is an integer of 1-3. a ¹ and a ^2, which may be the same or different, each represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a -COO-Z ³ via -COO-Z ³ or a hydrocarbon group. Z ³ represents a hydrogen atom or an optionally substituted hydrocarbon group.

In the general formula (II), X ⁰ is -COO -, - OCO -, - (CH 2) k -OCO -, - (CH 2) k -COO -, - O -, - CONHCOO -, - CONHCO, - It represents one or more linking groups selected from SO ₂ —, —CO—, —CONZ ³ —, and SO ₂ NZ ³ —. Here, Z ³ represents a hydrogen atom or a hydrocarbon group, and b ¹ and b ² may be the same as or different from each other, and represent the same contents as a ¹ and a ² in the general formula (I). k represents an integer of 1 to 3. Q ⁰ represents an aliphatic group having 1 to 22 carbon atoms having a silicon atom-containing substituent.

In the general formula (I), Z ¹ in the substituent represented by V is a hydrogen atom, and as a preferred hydrocarbon group, an optionally substituted alkyl group having 1 to 22 carbon atoms (for example, a methyl group, Ethyl, propyl, butyl, heptyl, hexyl, octyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, 2-chloroethyl, 2-bromoethyl, 2-cyanoethyl , 2-methoxycarbonylethyl group, 2-methoxyethyl group, 2-bromopropyl group, etc.), an optionally substituted alkenyl group having 4 to 18 carbon atoms (for example, 2-methyl-1-propenyl group, 2- Butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group, 1-pentenyl group, 1-hexenyl group, 2-hexenyl group, 4-methyl -2-hexenyl group, etc.), an optionally substituted aralkyl group having 7 to 12 carbon atoms (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, chlorobenzyl group) , Bromobenzyl group, methylbenzyl group, ethylbenzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.), optionally substituted alicyclic group having 5 to 8 carbon atoms (for example, cyclohexyl group, 2 -Cyclohexylethyl group, 2-cyclopentylethyl group, etc.), optionally substituted aromatic group having 6 to 12 carbon atoms (for example, phenyl group, naphthyl group, tolyl group, xylyl group, propylphenyl group, butylphenyl group) , Octylphenyl group, dodecylphenyl group, methoxyphenyl group, ethoxyphenyl group, butoxy Phenyl group, decyloxyphenyl group, chlorophenyl group, dichlorophenyl group, bromophenyl group, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group , Dodeciloylamidophenyl group, etc.), a group consisting of a bridged hydrocarbon having 5 to 18 carbon atoms (for example, bicyclo [1,1,0] butane, bicyclo [3,2,1] octane, bicyclo [5, 2,0] nonane, bicyclo [4,3,2] undecane, adamantane and the like).

V is -C ₆ H ₄ - When referring to a benzene ring may have a substituent. Examples of the substituent include a halogen atom (for example, chlorine atom, bromine atom and the like), an alkyl group (for example, methyl group, ethyl group, propyl group, butyl group, chloromethyl group, methoxymethyl group and the like).

a ¹ and a ² may be the same as or different from each other, and are preferably a hydrogen atom, a halogen atom (eg, a chlorine atom, a bromine atom, etc.), a cyano group, or an alkyl group having 1 to 3 carbon atoms (eg, a methyl group). , Ethyl group, propyl group, etc.), —COO—Z ² or CH ₂ COOZ ² (Z ² is preferably a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group, an aralkyl group or an alicyclic group, Or an aryl group, which may be substituted, and specifically represents the same content as described for Z ¹ above.

In formula (II), X ⁰ is -COO -, - OCO -, - (CH 2) k -OCO -, - (CH 2) k -COO -, - O -, - CONHCOO -, - CONHCO, - It represents one or more linking groups selected from SO ₂ —, —CO—, —CONZ ³ —, and SO ₂ NZ ³ —. Q ⁰ represents an aliphatic group having 1 to 22 carbon atoms having a silicon atom-containing substituent, and the silicon atom-containing substituent is preferably a siloxane structure (or silyloxy structure) or a silyl group. Z ³ represents the same contents as those described for Z ¹ above.

b ¹ and b ² may be the same as or different from each other, and have the same meanings as a ¹ and a ² in the general formula (I). Preferred ranges for b ¹ and b ² are the same as those described for a ¹ and a ² . More preferable groups of a ¹ and a ^{2 in} the general formula (I) or b ¹ and b ^{2 in} the general formula (II) include a hydrogen atom and a methyl group.

  Of the silicone-based macromonomers (M) in the present invention, preferred are those represented by the following general formula (III).

In the general formula (III), a ¹ , a ² , b ¹ , b ² and V represent the same contents as those described in the general formulas (I) and (II), respectively. T represents -X ⁰ -Q ⁰ represented by the general formula ^{(II), X 0, Q} 0 represents the same contents as those explained in the general formula (II). W ¹ is a single bond, or —C (Z ⁶ ) (Z ⁷ ) — [Z ⁶ and Z ⁷ are each a hydrogen atom, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group or a hydroxyl group. -(CH = CH)-, a cyclohexylene group (hereinafter, the cyclohexylene group is represented by Cy, where Cy includes 1,2-, 1,3- and 1,4-cyclohexylene groups), -Ph -, - O -, - S -, - C (= O) -, - N (Z 8) -, - COO -, - SO 2 -, - CON (Z 8) -, - SO 2 N (Z 8 )-, -NHCOO-, -NHCONH- or -Si (Z ⁸ ) (Z ⁹ )-[Z ⁸ , Z ⁹ represents a hydrogen atom or a hydrocarbon group having the same contents as Z ¹ ], etc. It represents a single linking group selected from atomic groups or a linking group composed of any combination.

In another preferred embodiment of the present invention, the silicone macromonomer (M) is a macromonomer having a number average molecular weight of 1 × 10 ³ to 4 × 10 ⁴ represented by the following general formula (V).

In general formula (V), V, a ¹ , and a ² represent the same contents as described in general formula (I), and W ¹ represents the same contents as described in general formula (III). . R ^{1 to} R ⁷ each independently represents an alkyl group having 1 to 10 carbon atoms, a phenyl group, or an aralkyl group having 7 to 16 carbon atoms.

In the general formulas (I), (II), (III), and (V), particularly preferred examples of X ⁰ , V, a ¹ , a ² , b ¹ , and b ² are shown below.
X ⁰ represents one or more linking groups selected from —COO—, —OCO—, —O—, —CH ₂ COO—, and CH ₂ OCO—, and V represents all of the above (provided that Z ¹ Is a hydrogen atom), examples of a ¹ , a ² , b ¹ and b ² include a hydrogen atom or a methyl group.

As the silicone-based macromonomer, a silicone-based macromonomer represented by the general formula (V) is particularly preferable. Specific examples of the silicone-based macromonomer represented by the general formula (V) are listed below, but the scope of the present invention is not limited to these.

  Examples of commercially available silicone-based macromonomers include X-24-8201, X-22-174DX, X-22-2426 (manufactured by Shin-Etsu Chemical Co., Ltd.), FM-0711, FM-0721, FM-0725 (manufactured by Chisso Corporation), AK-5, AK-30, and AK-32 (manufactured by Toagosei Co., Ltd.) are preferred specific examples.

  The silicone-based macromonomer (M) in the present invention can be produced by a conventionally known synthesis method. For example, (1) a method based on an ion polymerization method in which various reagents are reacted with the end of a living polymer obtained by anionic polymerization or cationic polymerization to form a macromer, (2) a carboxyl group, a hydroxy group, an amino group, etc. in the molecule Using a polymerization initiator and / or a chain transfer agent containing a reactive group of a radical polymerization method by reacting various reagents with a terminal reactive group-bonded oligomer obtained by radical polymerization to form a macromer, (3) A method by a polyaddition condensation method in which a polymerizable double bond group is introduced into the oligomer obtained by polyaddition or polycondensation reaction in the same manner as the above radical polymerization method.

Specifically, P.I. Dryfuss & R.D. P. Quirk, Encyclopedia, Polymer Science Engineering (Encycl.Polym.Sci.Eng.), Vol. 7, 551 (1987), p. F. Rempp & E. Franta, Advanced Polymer Science (Adv. Polym. Sci.), 58, 1 (1984), V. Percec, Applied Polymer Science (Appl. Polym. Sci.), 285, 95 (1984) Asami, M .; Takagi, Macromolecular Hemy Supplement (Makromol. Chem. Suppl.), Vol. 12, 163 (1985), p. Rempp et al., (Makromol. Chem. Suppl), 8, 3 (1987), Yusuke Kawakami, Kagaku Kogyo, 38,
56 (1987), Yamashita Tatsuya, Polymer, 31, 988 (1982), Kobayashi Shiro, Polymer, 30, 625 (1981), Toshinobu Higashimura, Journal of the Japan Adhesion Society, 18, 536 (1982), Koichi Ito, Polymer Processing, 35, 262 (1986), Shiro Togi, Takashi Tsuda, Functional Materials 1987, No. It can be synthesized according to the methods described in reviews such as 10, 5 and the literature and patents cited therein.

As for the molecular weight of the silicone-based macromonomer (M) of the present invention, the number average molecular weight is preferably in the range of 1 × 10 ³ to 4 × 10 ⁴ in terms of polystyrene by GPC method, more preferably 1 × 10 ³ to 2 The range is × 10 ⁴ . By setting the molecular weight to 1 × 10 ³ or more, the dispersibility is good and nozzle clogging does not occur, and good dischargeability is obtained. Moreover, by making the molecular weight less than 4 × 10 ⁴ , solubility in a non-aqueous solvent is secured, and a satisfactory dispersion effect is obtained.

  On the other hand, in the silicone-based graft copolymer, the monomer constituting the main chain portion insoluble in the non-aqueous solvent is preferably a monomer (monomer) represented by the following general formula (IV). The monomer represented by the general formula (IV) is a monomer that can be a copolymer component of the graft copolymer together with the silicone macromonomer.

In formula (IV), X ¹ represents a general formula (II) the same content as V in, preferably, -COO -, - OCO -, - CH 2 OCO -, - CH 2 COO -, - O -Or -Ph-. Q ¹ preferably represents a hydrogen atom, an aliphatic group having 1 to 22 carbon atoms, or an aromatic group having 6 to 12 carbon atoms. Specifically, those having the same contents as the aliphatic group and aromatic group of Z ¹ in the general formula (I) described above can be mentioned. c ¹ and c ² may be the same as or different from each other, and specific examples thereof include those having the same contents as a ¹ and a ^{2 in} formula (I). Particularly preferably, one of c ¹ and c ² represents a hydrogen atom.

  Preferable specific examples of the monomer represented by the general formula (IV) include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, styrene, vinyl toluene and the like.

The silicone-based graft copolymer in the present invention may contain another monomer that can be copolymerized with the monomer as a further copolymerization component. A monomer having two or more polymerizable functional groups may be further used in combination. Other monomers include, for example, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, hydroxyethyl methacrylate, dialkylaminoethyl methacrylate (eg, dimethylaminoethyl methacrylate) styrene, chlorostyrene, bromostyrene, vinyl naphthalene, polymerizable Heterocyclic compounds containing a double bond group (for example, vinylpyridine, vinylimidazoline, vinylthiophene, vinyldioxane, vinylpyrrolidone, etc.), unsaturated carboxylic acids (for example, acrylic acid,
Methacrylic acid, itaconic acid, crotonic acid, maleic acid and the like), itaconic anhydride and maleic anhydride.

  The monomer having two or more polymerizable functional groups may be a monomer having the same or different two or more of these polymerizable functional groups. Specific examples thereof are, for example, the same As monomers having a polymerizable functional group, styrene derivatives such as divinylbenzene and trivinylbenzene; polyhydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol # 200, # 400, # 600, 1, Methacrylic acid of 3-butylene glycol, neopentyl glycol, dipropylene glycol, polypropylene glycol, trimethylol bropan, trimethylol ethane, pentaerythritol, etc.) or polyhydroxyphenol (e.g. hydroquinone, resorcin, catechol and derivatives thereof), acrylic Or esters of crotonic acid, vinyl ters or allyl ethers; vinyl esters of dibasic acids (e.g. malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, itaconic acid, etc.), allyl steal Branches, vinylamide or allylamide; polyamines (eg, ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, etc.) and carboxylic acids containing vinyl groups (eg, methacrylic acid, acrylic acid, crotonic acid, allyl) Condensates with acetic acid and the like).

  Examples of monomers having different polymerizable functional groups include, for example, carboxylic acids containing vinyl groups (for example, methacrylic acid, acrylic acid, methacryloyl acetic acid, acryloyl acetic acid, methacryloyl propionic acid, acryloyl propionic acid, itaconyl yl acetic acid, Vinyl of itaconyloxypropionic acid, a reactant of carboxylic anhydride and alcohol or amine (e.g., allyloxycarbonyl bropionic acid, allyloxycarbonylacetic acid, 2-allyloxycarbonylbenzoic acid, allylaminocarbonylpropionic acid, etc.) Ester derivatives or amide derivatives containing groups (for example, vinyl methacrylate, vinyl acrylate, vinyl itaconate, allyl methacrylate, allyl acrylate, allyl itaconate, methacryloyl vinyl acetate, methacryloyl) Vinyl ropionate, allyl methacryloyl propionate, vinyl oxycarbonyl methyl ester methacrylate, vinyl oxycarbonyl methyl oxycarbonyl ethylene ester, N-allyl acrylamide, N-allyl methacrylamide, N-allyl itaconate amide, methacryloyl propionate allyl amide Etc.); and amino alcohols (for example, aminoethanol, 1-aminopropanol, 1-aminobutanol, 1-aminohexanol, 2-aminobutanol, etc.) and a condensate of a carboxylic acid containing a vinyl group. It is done.

The amount of the silicone-based macromonomer of the present invention and the monomer represented by the general formula (IV) is not particularly limited. The usage-amount of a macromonomer is 5-95 mass%.
Any other monomer than the monomer represented by the general formula (IV) may be used as long as it is a copolymerizable monomer, but preferably, the entire silicone-based graft copolymer in the present invention is used. In the polymerization component, the proportion of these other monomers is preferably 30% by mass or less. In particular, in the case of a monomer having two or more polymerizable functional groups, the amount used is preferably 10% by mass or less of the total monomers.

A method for producing a silicone-based graft copolymer in the present invention will be described. The silicone-based graft copolymer of the present invention includes a silicone-based macromonomer (M) having the general formulas (I) and (II) (preferably a macromonomer represented by the general formula (III)), or the general Manufacture by copolymerizing the silicone-based macromonomer (M) represented by the formula (V), the monomer represented by the general formula (IV) and, if necessary, other monomers in a desired ratio. Can do. As a polymerization method, it can be obtained by a conventionally known method such as solution polymerization, suspension polymerization, precipitation polymerization or emulsion polymerization. For example, in solution polymerization, a monomer is added at a predetermined ratio in a solvent such as benzene and toluene, and a copolymer solution is prepared by a radical polymerization initiator such as azobisisobutyronitrile, benzoyl peroxide, and lauryl peroxide. Obtainable. A desired copolymer can be obtained by adding this to a dry or poor solvent. In suspension polymerization, a monomer can be suspended in the presence of a dispersant such as polyvinyl alcohol or polyvinylpyrrolidone, and a copolymer can be obtained in the presence of a radical polymerization initiator. In these polymerizations, chain transfer agents such as mercaptans such as lauryl mercaptan can also be used to adjust the molecular weight.

The molecular weight of the silicone-based graft copolymer of the present invention is preferably in the range of 1 × 10 ^{4 to} 5 × 10 ⁵ , more preferably 2 × 10 ⁴ to 1 × 10 ⁵ in terms of polystyrene by GPC method. It is a range. By setting the molecular weight to 1 × 10 ⁴ or more, the dispersibility is good and nozzle clogging does not occur, and good dischargeability is obtained. Further, when the molecular weight is 5 × 10 ⁵ or less, solubility in a non-aqueous solvent is ensured, and a satisfactory nozzle clogging effect is obtained. The glass transition temperature of the silicone-based graft copolymer of the present invention is preferably in the range of 5 ° C or higher. When the glass transition temperature is 5 ° C. or higher, the graft copolymer can be easily handled without blocking.

  Next, specific examples of the silicone-based graft copolymer of the present invention are listed below, but the scope of the present invention is not limited thereto.

* FM-0725: Dimethylsiloxane macromonomer having a terminal methacryloyl group (manufactured by Chisso Corporation, number average molecular weight 10,000)
FM-0721: Dimethylsiloxane macromonomer having a terminal methacryloyl group (manufactured by Chisso Corporation, number average molecular weight 5,000)
FM-0711: Dimethylsiloxane macromonomer having a terminal methacryloyl group (manufactured by Chisso Corporation, number average molecular weight 1,000)
X-24-2401: Dimethylsiloxane macromonomer having a terminal methacryloyl group (manufactured by Shin-Etsu Chemical Co., Ltd., n = 25, number average molecular weight 2,100)
X-22-2426: Dimethylsiloxane macromonomer having a terminal methacryloyl group (manufactured by Shin-Etsu Chemical Co., Ltd., n = 150, number average molecular weight 11,400)
MMA; methyl methacrylate DVB: divinylbenzene MAA: methacrylic acid

In the present invention, it is preferable to use a resin (binder resin) that is insoluble or swellable in a non-aqueous solvent in order to improve the dispersibility by mixing with the colorant or to improve the fixability of the colorant. As such a resin, various known natural or synthetic resins can be used. For example, olefin polymers and copolymers (for example, polyethylene, polypropylene, polyisobutylene, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer). Polymers, ethylene-methacrylate copolymers, ethylene-methacrylic acid copolymers, etc.), polymers of styrene and its derivatives and copolymers (for example, butadiene-styrene copolymers, isoprene-styrene copolymers, styrene-methacrylates). Copolymer, styrene-acrylate copolymer, etc.), acrylate polymer and copolymer, methacrylate polymer and copolymer, itaconic acid diester polymer and copolymer, maleic anhydride copolymer, Rosin resin, hydrogenated rosin resin Examples include petroleum resin, hydrogenated petroleum resin, maleic acid resin, terpene resin, hydrogenated terpene resin, chroman-indene resin, cyclized rubber-methacrylic acid ester copolymer, and cyclized rubber-acrylic acid ester copolymer. .

  Preferred resins include a part that is solvated in a solvent and a solvent in a solvent because it has a function of adsorbing to a colorant particle in which a pigment is dispersed in a resin insoluble in a dispersion medium and the like and is well dispersed in a non-aqueous solvent. A random copolymer having a portion that is difficult to be combined and a portion having a polar group, or a graft copolymer disclosed in JP-A-3-188469 is preferred. For example, examples of the monomer that solvates with a solvent after polymerization include lauryl methacrylate, stearyl methacrylate, 2-ethylhexyl methacrylate, and cetyl methacrylate. Examples of monomers that are difficult to solvate with the solvent after polymerization include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, styrene, and vinyl toluene. Monomers containing polar groups include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, styrene sulfonic acid or alkali salts thereof, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, vinyl pyridine, vinyl Examples include basic group monomers such as pyrrolidine, vinylpiperidine, and vinyllactam.

  The used amount of the colorant (pigment) and the binder resin is 0.3 to 10 parts by mass of the binder resin with respect to 1 part by mass of the colorant. Preferably, 0.4 to 7 parts by mass of the binder resin is used with respect to 1 part by mass of the colorant. More preferably, the binder resin is used in an amount of 0.5 to 5 parts by mass with respect to 1 part by mass of the colorant. The pigment dispersion effect at the time of kneading | mixing is acquired because the usage-amount of binder resin shall be 0.3 mass part or more with respect to a coloring agent. In addition, when the amount of the binder resin used is 10 parts by mass or less with respect to the colorant, the required image density can be obtained without greatly reducing the pigment density in the ink composition.

  The basic constituent materials in the present invention are as described above, but a surfactant and various additives may be appropriately added to the ink-jet ink composition and the electrophotographic liquid developer as desired.

  Various additives may be added to the ink composition of the present invention as desired. The ink composition is arbitrarily selected depending on the material and structure of the ink jet system or the ink jet discharge head, the ink supply unit, and the ink circulation unit, and is contained as an ink composition. For example, additives described in Takeshi Amari “Inkjet Printer Technology and Materials”, Chapter 17, published by CMC Co., Ltd. (1998) are used.

Specifically, fatty acids (for example, C6-C32 monocarboxylic acid, polybasic acid; for example, 2-ethylhexynoic acid, dodecenyl succinic acid, butyl succinic acid, 2-ethylcaproic acid, lauric acid, palmitic acid, elaidin Acid, linolenic acid, ricinoleic acid, oleic acid, stearic acid, enanthic acid, naphthenic acid, ethylenediaminetetraacetic acid, abietic acid, dehydroabietic acid, hydrogenated rosin etc.), resin acid, alkylphthalic acid, alkylsalicylic acid, etc. (As metals of metal ions, Na, K, Li, B, Al, Ti, Ca, Pb, Mn, Co, Zn, Mg, Ce, Ag, Zr, Cu, Fe, Ba, etc.), surface active compounds (For example, as an organic phosphoric acid or a salt thereof, a mono-, di- or trialkylphosphorus composed of an alkyl group having 3 to 18 carbon atoms Organic sulfonic acids or salts thereof such as long chain aliphatic sulfonic acids, long chain alkylbenzene sulfonic acids, dialkylsulfosuccinic acids, etc. or metal salts thereof, amphoteric surface active compounds such as phospholipids such as lecithin and kephalin) , Alkyl group-containing surfactants containing a fluorine atom and / or a dialkylsiloxane bonding group, aliphatic alcohols (for example, higher alcohols consisting of branched alkyl groups having 9 to 20 carbon atoms, benzyl alcohol, phenethyl alcohol) Cyclohexyl alcohol, etc.), polyhydric alcohols {for example, alkylene glycols having 2 to 18 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-he Sundiol, dodecanediol, etc.)}; alkylene ether glycols having 4 to 1000 carbon atoms (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); fats having 5 to 18 carbon atoms Cyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); C12-C23 bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.) C2-C18 alkylene oxides (ethylene oxide) , Propylene oxide, butylene oxide, α-olefin oxide, etc.) adducts, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol Polyols such as sorbitol; trihydric to octahydric or higher phenols (trisphenol PA, phenol novolac, cresol novolac, etc.); C2-C18 alkylene oxide adducts (additions) of the above trivalent or higher polyphenols 2-20), polyhydric alcohol ether derivatives (polyglycol alkyl ethers, alkylaryl polyglycol ethers, etc.), polyhydric alcohol fatty acid ester derivatives, polyhydric alcohol ether oleate derivatives (eg, ethylene glycol) Monoethyl acetate, diethylene glycol monobutyl acetate, propylene glycol monobutyl propiolate, sorbitan monomethyl dioxanolate, etc.), alkyl naphthalene sulfonate, alkyl aryl sulfate Compounds such as sulfonates, and the like, but not limited thereto. The amount of each additive used is preferably adjusted so that the surface tension of the ink composition is 15 to 60 mN / m (at 25 ° C.) and the viscosity is 1.0 to 40 cP.

  In the liquid developer of the present invention, a charge control agent is used for the purpose of enhancing charge characteristics or improving image characteristics.

Conventionally known charge control agents for liquid developers used in the present invention can be used. For example, metal salts of fatty acids such as naphthenic acid, octenoic acid, oleic acid, stearic acid, metal salts of sulfosuccinic acid esters, Japanese Patent Publication No. 45-556, Japanese Patent Publication No. 52-37435, Japanese Patent Publication No. 52-37049 Oil-soluble sulfonic acid metal salts disclosed in Japanese Patent Publication No. 45-9594, phosphoric acid ester metal salts disclosed in Japanese Patent Publication No. 45-9594, abietic acid or hydrogenated abietin disclosed in Japanese Patent Publication No. 48-25666 Metal salts of acids, alkylbenzene sulfonic acid Ca salts disclosed in Japanese Patent Publication No. 55-2620, JP-A 52-107837, 52-38937, 57-90643, and 57-139753 Nonionics such as metal salts of aromatic carboxylic acids or sulfonic acids, polyoxyethylated alkylamines indicated in the publication Surfactants, fats and oils such as lecithin and linseed oil, polyvinyl pyrrolidone, organic acid esters of polyhydric alcohols, phosphate ester surfactants disclosed in JP-A-57-210345, JP-B 56-24944 The sulfonic acid resin etc. which are shown by gazette gazette can be used. In addition, amino acid derivatives described in JP-A-60-21056 and 61-50951 can also be used. Moreover, the copolymer etc. which contain the maleic acid half amide component described in each gazette of Unexamined-Japanese-Patent No. 60-173558 and 60-179750 are mentioned. Further, JP-A-54-317
And quaternized amine polymers described in JP-A No. 39 and JP-B-56-24944.

Among these, preferred are a metal salt of naphthenic acid, a metal salt of dioctylsulfosuccinic acid, a copolymer containing the maleic acid half amide component, lecithin, and the amino acid derivative. As these charge control agents, two or more compounds can be used in combination. The charge control agent as described above is preferably 0.001 to 10.0 parts by mass with respect to 1000 parts by mass of the non-aqueous solvent. Further, various additives may be added as desired, and the upper limit of the total amount of these additives is regulated by the electric resistance of the developer. That is, when the electrical resistance of the liquid developer with the toner particles removed becomes lower than 10 ⁹ Ωcm, it becomes difficult to obtain a high-quality continuous tone image. Therefore, the amount of each additive added is controlled within this limit. It is necessary.

Next, a method for producing ink will be described. For the production of the ink, a general method known as a production method of various pigment inks can be used. For example, colorant particles coated with a colorant with a resin are formed by coating the colorant with a resin to form a colored admixture, and then dispersing the colored admixture in a fine particle in a non-aqueous solvent. be able to. First, a process of making a color mixture by coating a colorant with a resin will be described. The colored mixture is prepared by the following method, for example.
1) A method in which a colorant and a resin are melt-kneaded using a kneader such as a roll mill, a Banbury mixer, or a kneader at a temperature equal to or higher than the softening point of the resin, and pulverized after cooling to obtain a colored mixture.
2) Dissolve the resin in a solvent, add a colorant, wet disperse with a ball mill, attritor, sand grinder, etc., evaporate the solvent to obtain a colored admixture, or disperse the dispersion in a non-solvent of the resin A method of pouring and precipitating to obtain an admixture, followed by drying to obtain a colored admixture.
3) A method in which a pigment-containing paste (wet cake) is kneaded with a resin or a resin solvent by a flushing method, water is replaced with a resin or a resin solution, and then the water and the solvent are dried under reduced pressure to obtain a colored mixture.

Next, a dispersion process for dispersing the colored admixture described above in the form of fine particles in a non-aqueous solvent will be described.
In the dispersion step, the pigment dispersant of the present invention is used to disperse in fine particles and stabilize the dispersion in a non-aqueous solvent. Examples of the use of the color mixture and the pigment dispersant include the following methods.
1. A pigment composition in which a color admixture and a pigment dispersant are mixed in advance is added and dispersed in a non-aqueous solvent.
2. A colored admixture and a pigment dispersant are separately added and dispersed in a non-aqueous solvent.
3. A dispersion obtained by separately dispersing a colored admixture and a pigment dispersant in advance in a non-aqueous solvent is mixed. In this case, the pigment dispersant may be dispersed only with a solvent.
4). There is a method of dispersing a colored admixture in a non-aqueous solvent and then adding a pigment dispersant to the obtained pigment dispersion, and any of these methods can achieve the intended effect.
As a machine for mixing or dispersing the above colored admixture in a non-aqueous solvent, a dissolver, a high speed mixer, a homomixer, a kneader, a ball mill, a roll mill, a sand mill, an attritor or the like can be used. The range of the average particle diameter of the colorant particles formed by dispersing the colored admixture is preferably 0.01 to 10 μm, more preferably 0.01 to 3 μm, and particularly preferably 0.01 to 1.0 μm. Range.

  As the usage-amount of the silicone type graft copolymer of this invention used at the above-mentioned dispersion | distribution process, 10-300 mass parts is preferable with respect to 100 mass parts of pigments. By adding the silicone-based graft copolymer in an amount of 10 parts by mass or more, the pigment dispersion effect is enhanced, and by setting it to 300 parts by mass or less, the dispersion effect and cost are excellent.

  The ink-jet ink composition of the present invention can be used as an oil-based ink in various ink-jet recording systems. Examples of the ink-jet recording system include electrostatic ink-jets represented by slit jets such as the piezo system, Toshiba and NTT. Examples thereof include a printer and a thermal ink jet printer.

  EXAMPLES Hereinafter, although an Example and a comparative example further demonstrate this invention, this invention is not restrict | limited to these examples.

Production Example 1 of Silicone Graft Copolymer 1: Specific Example (2)
300 g of toluene, 60 g of styrene and 140 g of FM-0725 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a silicone macromonomer were added to a 1 L round bottom flask equipped with a reflux condenser, a stirring blade and a nitrogen introduction tube, and the temperature was raised to 90 ° C. in a nitrogen stream. Thereafter, 2 g of 1,1′-azobis (1-cyclohexanecarbonitrile) was added as a polymerization initiator, and a polymerization reaction was performed at 90 ° C. for 4 hours. Next, 1.0 g of an initiator was added for 10 hours, and 0.5 g of a polymerization initiator was further added for a polymerization reaction for 10 hours. After completion of the polymerization, the reaction mixture was cooled to room temperature, 200 g of toluene was added, and reprecipitation was performed in 10 liters of methanol. After filtration, the obtained white powder was dried to obtain 182 g of the powder of specific example (2) of the silicone-based graft copolymer. The resin of specific example (2) had a weight average molecular weight of 4.5 × 10 ⁴ . Moreover, the solution which melt | dissolved 20 mass% of resin of the specific example (2) in Isopar G made from Exxon was white.

Production Examples 2-12 of Silicone Graft Copolymer: Specific Examples (3) to (7), (9) to (12), (15), (19)
Except that the styrene (monomer of general formula IV) and the silicone macromonomer (M) used in Production Example 1 of the silicone-based graft copolymer were replaced with monomers corresponding to the specific examples in Table 2 below, Production Example 1 and By reacting in the same manner, specific examples (3) to (7), (9) to (12), (15) and (19) of the silicone-based graft copolymer were produced. Table 2 shows the weight average molecular weight of specific examples of each graft copolymer. Specific examples (3) to (7), (9) to (12), (15), and a solution in which 20% by mass of the resin of (19) was dissolved in Isopar G were transparent to white.

Production Examples 1 and 2 for comparative pigment dispersants: (R-1) and (R-2)
In Production Example 1, a comparative pigment dispersant (exclusively the same as Production Example 1 except that silicone monomer TM-0701 (manufactured by Shin-Etsu Chemical Co., Ltd.) having a number average molecular weight of 423 was used instead of silicone macromonomer FM-0725. R-1) Further, in Production Example 1, a comparative pigment dispersant (R-) was prepared in the same manner as in Production Example 1, except that 90 g of styrene and 110 g of TM-0701 (manufactured by Shin-Etsu Chemical Co., Ltd.) were used as the silicone macromonomer. 2) was synthesized. The weight average molecular weights of the comparative pigment dispersants (R-1) and (R-2) were 5.7 × 10 ⁴ and 11.0 × 10 ⁴ , respectively.

Production Example 3 for Comparative Pigment Dispersant: (R-3)
A mixed solution of 45 g of styrene, 55 g of one-end methacryloyl group-containing stearyl methacrylate macromonomer (Mw = 12,000, see the following structure) and 200 g of toluene was placed in a four-necked flask and heated to a temperature of 80 ° C. with stirring in a nitrogen stream. . As a polymerization initiator, 1 g of 1,1′-azobis (1-cyclohexanecarbonitrile) was added and polymerized at 80 ° C. for 24 hours. After the polymerization, the mixture was cooled to room temperature, and further 200 g of toluene was added and reprecipitated in 4 liters of methanol. After filtration, the obtained white powder was dried to obtain 92 g of a comparative pigment dispersant (R-3) having a weight average molecular weight of 6.6 × 10 ⁴ .

Production Example 4 for Comparative Pigment Dispersant: (R-4)
Comparison of weight average molecular weight 5.7 × 10 ^{4 in} the same manner as in Production Example 3 except that 30 g of styrene and 70 g of stearyl methacrylate macromonomer containing one terminal methacryloyl group (Mw = 12,000) were used in Production Example 3. 90 g of a pigment dispersant (R-4) was obtained.

Ink Composition Example 1: IJ-1
100 parts by mass of linole blue FG-7350 (Pigment Blue 15: 3 manufactured by Toyo Ink Co., Ltd.) as a blue pigment, styrene / vinyl toluene / lauryl methacrylate / trimethylammonium ethyl methacrylate (anion, p-toluenesulfonic acid) copolymer as a resin ( (47/47/1/5 molar ratio) 100 parts by mass was preliminarily pulverized with a trioblender and mixed well, and then melt-kneaded (120 minutes) with a desktop kneader PBV (manufactured by Irie Trading Co., Ltd.) heated to 100 ° C. Next, 10 parts by mass of the pigment kneaded product, 70.0 parts by mass of Isopar G, and 25 parts of a 20% by mass solution prepared by dissolving and dissolving a specific example (7) of a silicone-based graft copolymer as a pigment dispersant in Isopar G. Together with 250 parts by mass of 3G-X glass beads and 6 hours with a paint shaker (Toyo Seiki KK). When the volume average particle size of the pigment resin particles in the dispersion was measured with an ultracentrifugal automatic particle size distribution analyzer CAPA700 (Horiba Seisakusho), it was well dispersed as 0.22 μm.

  The pigment resin particle dispersion from which the glass beads had been removed by filtration was once concentrated by evaporation of the solvent, and then diluted with Isopar G to prepare ink composition IJ-1. The obtained ink composition IJ-1 has a pigment resin particle concentration of 14.3% by mass, a viscosity of 13.0 cP (E-type viscometer, measured at a temperature of 25 ° C.), and a surface tension of 23 mN / m (Kyowa Interface Science Co., Ltd.). Automatic surface tension meter, measured at a temperature of 25 ° C.).

  Using a color facsimile Saiyuki UX-E1CL (manufactured by Sharp Corporation) as an ink jet recording apparatus, filling the ink composition IJ-1 and drawing it on Fuji Photo Film Inkjet Paper High Grade exclusive paper, stable without nozzle clogging Was discharged. The obtained drawn image had no blur and was a good quality and clear image density of 1.5. Next, a full solid pattern was printed, and after the printed matter was dried, the solid portion was rubbed with a finger. As a result, it was found that there was no background stain and it was extremely excellent in scratch resistance. The ink composition did not show sedimentation aggregation even after long-term storage and had very good dispersibility.

The evaluation criteria are shown below.
<Ink dispersion stability>
After preparing the ink, it was left at a temperature of 35 ° C. for 1 month. After shaking the container several times by hand, the particle size (particle size distribution measuring apparatus CAPA-700) and the presence or absence of aggregates were evaluated.
○: No change in size and no aggregates are observed.
(Triangle | delta): Size increases a little and a small aggregate is seen.
X: The size is greatly increased and there are many large and small aggregates.
<Ink ejection stability>
○: No clogging even after 24 hours of continuous discharge.
Δ: Clogging occurs after several hours and no discharge occurs.
X: Clogging occurs immediately and no discharge occurs.
<Image quality>
○: Good with no bleeding and image defects.
(Triangle | delta): Although there is no blur, there exists an image defect in one part.
X: Bleeding and image defects are defective.
<Image scratch resistance>
○: There is no background stain at all visually.
(Triangle | delta): Soil dirt can be confirmed slightly visually.
X: Ground dirt can be easily confirmed visually.

Comparative Examples 1 and 2: Comparative ink compositions IJR-1 and IJR-2
In order to compare with the specific example (7) of the pigment dispersant of the present invention in which styrene / silicone macromonomer = 45/55 (mass ratio), instead of the specific example (7) of the pigment dispersant in Example 1, Comparative pigment dispersant (R-2) which is a random copolymer using a silicone monomer instead of a silicone macromonomer at the same composition ratio, and a comparative pigment dispersion which is a graft copolymer using a stearyl methacrylate macromonomer Comparative ink compositions IJR-1 and IJR-2 were prepared in exactly the same manner as in Example 1, except that the agent (R-3) was used. The surface tension of the ink composition was 23 mN / m, and the viscosity was adjusted to 13 cP by changing the pigment resin particle concentration. Table 3 shows the performance evaluation results of the comparative ink compositions IJR-1 and IJR-2.

Ink Composition Example 2: IJ-2
Example 1 is the same as Example 1 except that the specific example (2) of the silicone-based graft copolymer was used instead of the specific example (7) of the silicone-based graft copolymer that is the pigment dispersant of the present invention. Ink composition IJ-2 was prepared exactly as described above. The ink composition IJ-2 was adjusted to have a surface tension of 23 mN / m and a viscosity of 13 cP by changing the pigment resin particle concentration. The volume average particle diameter of the pigment resin particles in the dispersion liquid of the ink composition IJ-2 was well dispersed at 0.38 μm. When the drawing performance of the ink composition IJ-2 was evaluated in the same manner as in Example 1, it was discharged stably for a long time without nozzle clogging, and the obtained drawn image had no image blur and had a sufficient image density. It was good and clear. It was found that the solid portion was excellent in scratch resistance. The ink composition IJ-2 was extremely good in dispersibility without sedimentation and aggregation even when stored for a long time.

Comparative Examples 3 and 4: Comparative ink compositions IJR-3 and IJR-4
In order to compare with the specific example (2) of the pigment dispersant of the present invention in which styrene / silicone macromonomer = 30/70 (mass ratio), instead of the specific example (2) of the pigment dispersant in Example 2, Comparative pigment dispersant (R-1) which is a random copolymer using a silicone monomer instead of a silicone macromonomer at the same composition ratio, and a comparative pigment dispersion which is a graft copolymer using a stearyl methacrylate macromonomer Comparative ink compositions IJR-3 and IJR-4 were prepared in the same manner as in Example 2 except that the agent (R-4) was used. The surface tension of the ink composition was 23 mN / m, and the viscosity was adjusted to 13 cP by changing the pigment resin particle concentration. Table 4 shows the performance evaluation results of the comparative ink compositions IJR-3 and IJR-4.

From the results of Tables 3 and 4, the ink compositions IJ-1 and IJ-2 using the silicone-based graft copolymer composed of the silicone macromonomer of the present invention as a non-aqueous solvent-based pigment dispersant are pigment resins. Particles are finely dispersed and have excellent dispersion stability, nozzle clogging is excellent, ejection stability is excellent, there is no ink bleeding, a high quality, clear drawing image is given, and drawing image scratch resistance is excellent I understand that.
On the other hand, a comparative ink composition IJR-1 using a random copolymer using a silicone monomer instead of a silicone macromonomer and a graft copolymer using a stearyl methacrylate macromonomer as a comparative pigment dispersant at the same composition ratio In ~ IJR-4, coarse particles of pigment resin particles were mixed, and remarkable aggregation occurred during short-term storage. As for the ejection stability, ink ejection becomes unstable within one hour of continuous operation, nozzle clogging occurs, and the drawn image also has a defective white streak that is defective from the beginning of drawing and the image is missing did. In addition, as for the scratch resistance of the drawn image, in any case, when the solid image portion was rubbed with a finger, the image portion was missing.
As described above, the ink composition using the silicone-based graft copolymer comprising the silicone macromonomer of the present invention as a non-aqueous solvent-based pigment dispersant is excellent in dispersion stability in which the pigment is finely dispersed. It can be seen that the ink performance is good.

Ink Composition Examples 3 to 10: IJ-3 to IJ-10
In Example 1, instead of the specific example (7) of the silicone-based graft copolymer that is the pigment dispersant of the present invention, the silicone-based graft copolymer shown in Table 5 below was used as the pigment dispersant. Ink compositions IJ-3 to IJ-10 were prepared in exactly the same manner as in Example 1. The ink compositions IJ-3 to IJ-10 were adjusted to have a surface tension of 23 mN / m and a viscosity of 10 to 14 cP by changing the pigment resin particle concentration. Table 5 shows the results of volume average particle diameters of the pigment resin particles in the dispersions of the ink compositions IJ-3 to IJ-10. Further, when the drawing performance of the ink compositions IJ-3 to IJ-10 was evaluated in the same manner as in Example 1, all the ink compositions were stably ejected for a long time without nozzle clogging, and the obtained drawing was obtained. The image was clear and of good quality with no image blur and sufficient image density. It was found that the solid portion was excellent in scratch resistance. Ink compositions IJ-3 to IJ-10 exhibited very good dispersibility without sedimentation and aggregation even when stored for a long period of time.

Ink Composition Example 11: IJ-11
A pigment kneaded material was prepared in the same manner as in Example 1, and then dispersed using silicone oil instead of Isopar G as a non-aqueous solvent. Pigment kneaded material 5 parts by weight, silicone oil KF96L-1.5 (manufactured by Shin-Etsu Chemical Co., Ltd.) 75 parts by weight, silicone graft copolymer specific example (2) as a pigment dispersant is heated to silicone oil KF96L-1.5 A 20% by mass solution prepared by dissolution was mixed with 25 parts by mass and 250 parts by mass of 3G-X glass beads with a paint shaker (Toyo Seiki KK) for 6 hours. The volume average particle diameter of the pigment resin particles in the dispersion was 0.25 μm and was well dispersed. The pigment resin particle dispersion from which the glass beads were removed by filtration was once concentrated by evaporation of the solvent, and then diluted with silicone oil KF96L-1.5 to prepare ink composition IJ-11. The obtained ink composition IJ-11 had a pigment resin particle concentration of 13.3% by mass, a viscosity of 13.5 cP, and a surface tension of 17 mN / m. Next, an ink jet recording apparatus MJP-1500 (manufactured by Microjet Co., Ltd.) is used as the ink jet recording apparatus, the ink composition IJ-11 is filled, and the ink is drawn on Fuji Photo Film ink jet paper high grade exclusive paper, and ink is used. When the drawing performance of the composition IJ-11 was evaluated, there was no nozzle clogging and it was discharged stably for a long time.
The obtained drawn image had a sufficient image density and was high-quality and clear. In addition, the ink composition IJ-11 showed very good dispersibility without precipitation or aggregation even when stored for a long time.

Comparative Examples 5 and 6: Comparative ink compositions IJR-5 and IJR-6
In order to compare with the pigment dispersant comprising the silicone-based graft copolymer of the present invention, a stearyl methacrylate macromonomer was used in place of the silicone macromonomer in Example 11 instead of the specific example (2) of the pigment dispersant. Comparative ink compositions IJR-5 and IJR-6 were prepared in exactly the same manner as in Example 11 except that the comparative pigment dispersants (R-3) and (R-4), which were graft copolymers, were used. Prepared. Since the comparative pigment dispersants (R-3) and (R-4) have low solubility in the silicone oil KF96L-1.5, the pigment kneaded material cannot be dispersed well, and the comparative ink composition has coarse particles. Remained and could not be used for the next evaluation.

  From Example 11 and Comparative Examples 5 and 6, only the ink composition using the silicone-based graft copolymer composed of the silicone macromonomer of the present invention as the silicone oil solvent-based pigment dispersant was dispersed in the fine particles of the pigment. It can be seen that the dispersion stability is also excellent and good ink performance is exhibited.

Ink Composition Examples 12 to 15: IJ-12 to IJ-15
In Example 11, instead of the specific example (2) of the silicone-based graft copolymer that is the pigment dispersant of the present invention, the silicone-based graft copolymer described in Table 6 below was used as the pigment dispersant. Ink compositions IJ-12 to IJ-15 were prepared in exactly the same manner as in Example 1. The ink compositions IJ-12 to IJ-15 were adjusted to have a surface tension of 17 mN / m and a viscosity of 10 to 14 cP by changing the pigment resin particle concentration. Table 6 shows the results of volume average particle diameters of the pigment resin particles in the dispersions of the ink compositions IJ-12 to IJ-15. Moreover, when the drawing performance of the ink compositions IJ-12 to IJ-15 was evaluated in the same manner as in Example 1, all the ink compositions were stably ejected for a long time without nozzle clogging, and the obtained drawn images were It had a sufficient image density and was clear with good quality. In addition, the ink compositions IJ-12 to IJ-15 exhibited very good dispersibility without sedimentation aggregation even when stored for a long period of time.

Ink Composition Example 16: IJ-16
The blue pigment resin particle dispersion of Example 1 was diluted with Isopar G so that the resin particle component was 6.0% by mass. Subsequently, an ink composition IJ-16 was prepared by adding an octadecene-half-maleic acid octadecylamide copolymer as a charge control agent so as to be 0.005 g / Isopar G 1 liter. The charge amount of the ink composition IJ-16 was measured using a development characteristic apparatus described in Japanese Patent Publication No. 64-696 (measured initial value of applied voltage 500 V, time-induced voltage induced on the back surface of the applied electrode). I went there. The ink composition IJ-16 showed a clear positive charge with an overall charge of 250 mV and a yellow resin particle charge of 212 mV, and was found to be extremely stable with almost no change in the amount of charge after one month. It was also found that the amount of charge can be easily controlled by the amount of charge control agent. When this ink composition IJ-16 was used as a liquid developer for electrophotography and a printing test was performed using a Ricoh wet copying machine DT-2500, an image having sufficient image density and good fixability was obtained. Further, this electrophotographic liquid developer has very little change in charge with time, and has excellent redispersibility and storage stability.

Claims (11)

  In a non-aqueous solvent pigment dispersant comprising a silicone-based graft copolymer and soluble in a non-aqueous solvent, the silicone-based graft copolymer comprises a monomer constituting a main chain portion insoluble in the non-aqueous solvent, A non-aqueous solvent pigment containing a monomer constituting a graft portion soluble in a non-aqueous solvent, wherein the monomer constituting the graft portion contains a silicone-based macromonomer (M) having a polymerizable group at the terminal Dispersant. The silicone-based macromonomer (M) has a polymerizable double bond group represented by the following general formula (I) at the end of the main chain of the silicone polymer comprising a repeating unit represented by the following general formula (II). The non-aqueous solvent pigment dispersant according to claim 1, which is a macromonomer having a number average molecular weight of 1 x 10 ³ to 4 x 10 ^{4 formed} by bonding.

In the general formula (I), V is _{-COO -, - COO (CH 2} ) m -, -OCO -, - OCO (CH 2) m -, - (CH 2) k -OCO -, - (CH 2) _k —COO—, —O—, —CONHCOO—, —CONHCO—, —CONH (CH ₂ ) _m —, —SO ₂ —, —CO—, —CONZ ¹ —, —SO ₂ NZ ¹ — or a phenylene group. To express. Here, Z ¹ represents a hydrogen atom or a hydrocarbon group, m represents an integer of 1 to 10, k is an integer of 1-3. a ¹ and a ^2, which may be the same or different, each represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a -COO-Z ³ via -COO-Z ³ or a hydrocarbon group. Z ³ represents a hydrogen atom or an optionally substituted hydrocarbon group.

In the general formula (II), X ⁰ is -COO -, - OCO -, - (CH 2) k -OCO -, - (CH 2) k -COO -, - O -, - CONHCOO -, - CONHCO, - It represents one or more linking groups selected from SO ₂ —, —CO—, —CONZ ² —, and SO ₂ NZ ² —. Here, Z ² represents a hydrogen atom or a hydrocarbon group, and b ¹ and b ² may be the same as or different from each other, and represent the same contents as a ¹ and a ² in the general formula (I). k represents an integer of 1 to 3. Q ⁰ represents an aliphatic group having 1 to 22 carbon atoms having a silicon atom-containing substituent. The non-aqueous solvent pigment dispersant according to claim 1, wherein the silicone-based macromonomer (M) is a macromonomer having a number average molecular weight of 1 × 10 ³ to 4 × 10 ⁴ represented by the following general formula (V).

In the general formula (V), V is _{-COO -, - COO (CH 2} ) m -, -OCO -, - OCO (CH 2) m -, - (CH 2) k -OCO -, - (CH 2) _k —COO—, —O—, —CONHCOO—, —CONHCO—, —CONH (CH ₂ ) _m —, —SO ₂ —, —CO—, —CONZ ¹ —, —SO ₂ NZ ¹ — or a phenylene group. To express. Here, Z ¹ represents a hydrogen atom or a hydrocarbon group, m represents an integer of 1 to 10, k is an integer of 1-3. a ¹ and a ^2, which may be the same or different, each represent a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a -COO-Z ³ via -COO-Z ³ or a hydrocarbon group. Z ³ represents a hydrogen atom or an optionally substituted hydrocarbon group. W ¹ is a single bond, or —C (Z ⁶ ) (Z ⁷ ) — [Z ⁶ and Z ⁷ are each a hydrogen atom, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group or a hydroxyl group. shown], - (CH = CH) - , a cyclohexylene group, -Ph -, - O -, - S -, - C (= O) -, - N (Z 8) -, - COO -, - SO 2 —, —CON (Z ⁸ ) —, —SO ₂ N (Z ⁸ ) —, —NHCOO—, —NHCONH— or —Si (Z ⁸ ) (Z ⁹ ) — [Z ⁸ , Z ⁹ is a hydrogen atom or Represents a hydrocarbon group having the same contents as Z ¹ ], and represents a single linking group selected from an atomic group such as linking group or any combination thereof. R ^{1 to} R ⁷ each independently represents an alkyl group having 1 to 10 carbon atoms, a phenyl group, or an aralkyl group having 7 to 16 carbon atoms. The non-aqueous solvent is an aliphatic saturated hydrocarbon having a viscosity of 3 cSt or less, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 22.5 to 28.0 mN / m (at 25 ° C.). The non-aqueous solvent pigment dispersant according to any one of claims 1 to 3. The non-aqueous solvent is a silicone oil having a viscosity of 0.5 to 20 cSt, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 15 to 21 mN / m (at 25 ° C). 4. The non-aqueous solvent pigment dispersant according to any one of 3 above.   2. An ink-jet ink composition comprising at least a colorant, a resin that is insoluble or swellable in the non-aqueous solvent, and a pigment dispersant in a non-aqueous solvent. The inkjet ink composition which is a non-aqueous solvent type pigment dispersant of any one of -3. In an inkjet ink composition comprising a non-aqueous solvent and at least a colorant, a resin insoluble or swellable in the non-aqueous solvent, and a pigment dispersant, the non-aqueous solvent is 3 cSt or less. An ink-jet ink composition, which is an aliphatic saturated hydrocarbon having a viscosity of 10 ¹⁰ Ω · cm or more and a surface tension in the range of 22.5 to 28.0 mN / m (at 25 ° C.). In an inkjet ink composition comprising a non-aqueous solvent and at least a colorant, a resin insoluble or swellable in the non-aqueous solvent, and a pigment dispersant, the non-aqueous solvent is 0.5 Viscosity of ˜20 cSt, specific resistance of 10 ¹⁰ Ω · cm or more, and 15 to 21 mN / m (2
An ink-jet ink composition which is a silicone oil having a surface tension in the range of 5 ° C.).   In a liquid developer for electrophotography, which contains at least a colorant, a resin insoluble or swellable in the nonaqueous solvent, a pigment dispersant, and a charge control agent in a nonaqueous solvent, the pigment dispersion An electrophotographic liquid developer, wherein the agent is the non-aqueous solvent pigment dispersant according to any one of claims 1 to 3. In the liquid developer for electrophotography, which comprises at least a colorant, a resin insoluble or swellable in the nonaqueous solvent, a pigment dispersant, and a charge control agent in a nonaqueous solvent. For electrophotography, the solvent is an aliphatic saturated hydrocarbon having a viscosity of 3 cSt or less, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 22.5 to 28.0 mN / m (at 25 ° C.) Liquid developer. In the liquid developer for electrophotography, which comprises at least a colorant, a resin insoluble or swellable in the nonaqueous solvent, a pigment dispersant, and a charge control agent in a nonaqueous solvent. An electrophotographic liquid developer, wherein the solvent is a silicone oil having a viscosity of 0.5 to 20 cSt, a specific resistance of 10 ¹⁰ Ω · cm or more, and a surface tension in the range of 15 to 21 mN / m (at 25 ° C.).