JP2003089757A - Colored resin fine particle and method for producing the same, aqueous dispersion of colored resin particle, ink, ink cartridge, recording unit, ink jet recording device, and ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide colored resin fine particles giving an image equipped with waterproof property, weather resistance, light fastness and scratch resistance, also excellent in dispersion stability and useful as a coloring material of an ink having a high color developing property in a high pigment concentration, and a method for producing the colored resin particles in a good efficiency, to prepare an ink, and the like. SOLUTION: The colored resin particles have a structure such that the pigment coated with a non-water soluble resin is contained in a capsule containing a copolymer of at least a polymerizable unsaturated monomer and a reactive emulsifier, the method for producing the colored resin fine particles is the one in which a phase transition emulsifying method is used as an emulsifying process, comprising the emulsifying process of at least the polymerizable unsaturated monomer, a coloring agent, the emulsifier and a polymerization initiator in an aqueous medium and a polymerizing process of the polymerizable unsaturated monomer, and also ink, ink cartridge, recording unit, ink jet-recording device and ink jet-recording method are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to colored resin fine particles and a method for producing the same, an aqueous dispersion of colored resin fine particles, an ink, an ink cartridge, a recording unit, an inkjet recording apparatus and an inkjet recording method. The colored resin fine particles and an aqueous dispersion thereof are particularly useful as, for example, a coloring material for inkjet ink.

[0002]

2. Description of the Related Art For example, a water-soluble dye is used as a coloring material in an ink used in a conventional ink jet recording method, and a recorded image by such an ink is required to have further improved water resistance. ing. Further, many water-soluble dyes to date have insufficient weather resistance, and further improvement in weather resistance is also demanded. On the other hand, as a means for improving the water resistance and weather resistance of a recorded matter, there is a technique of using a pigment as a coloring material and dispersing the pigment in water to form an ink. However, it is difficult to achieve both the dispersion stability of the pigment and the ejection stability of inkjet recording, and the recorded image obtained with the pigment ink still has room for improvement, especially in scratch resistance on plain paper. Is left.

A number of means for improving such problems have been proposed so far, and for example, there is a technique of adding a resin to a pigment ink for the purpose of improving scratch resistance. However, there remains a problem that the viscosity of the ink increases due to the added resin. A technique for adding resin particles has been proposed for the purpose of suppressing an increase in the viscosity of the ink, but since the resin particles and the pigment are separately dispersed, improvement in scratch resistance was insufficient. .

On the other hand, a technique for coating the pigment with a resin has been proposed. A technique has been proposed in which the adsorptivity of the resin to the pigment is improved by controlling the hydrophobic portion and the hydrophilic portion of the resin, but in the production method of mixing the pigment and the resin, the pigment is not adsorbed to the pigment and floats. The resin that remains remains in the ink system, which may cause an increase in the viscosity of the ink and may impair the ejectability of the ink. As a manufacturing method in which such a free resin does not remain, a pigment is added from the stage of the monomer before the resin is prepared, the monomer is polymerized in the presence of the pigment, and the pigment is coated with the resin. Proposals have been made.

And, for example, Japanese Patent Laid-Open No. 9-279073.
In the publication, there is a technique for obtaining colored resin fine particles by emulsion polymerization of an unsaturated monomer with addition of a colorant having an affinity for the unsaturated monomer,
Further, JP-A-11-12512 discloses a technique of adding a pigment to an ethylenically unsaturated monomer and performing emulsion polymerization to obtain an inkjet ink.

[0006]

However, according to the study by the present inventors, it was difficult to obtain colored resin fine particles having a small particle diameter by the manufacturing method described in Japanese Patent Laid-Open No. 9-279073. . Further, in this case, the pigment / monomer mass ratio is about 1/10, and with such a low concentration of colored resin fine particles, a sufficient image density cannot be obtained when formed into an ink, while the pigment concentration is increased. If the pigment concentration at the time of dispersion is increased in this way, the mixture becomes extremely viscous, and it becomes more difficult to disperse the mixture into a fine particle state suitable for the color material of the ink.

According to the studies conducted by the present inventors, it is difficult to control the particle size of the method described in JP-A No. 11-12512, and the stability of the particle size with time is also high. It was speculated that it would be damaged. Furthermore, according to the examples, the mass ratio of pigment to polymerizable unsaturated monomer is about 1 /
When it is as low as 10, and a pigment having such a low pigment concentration is used as the color material of the ink, a sufficient image density cannot be obtained. On the other hand, if the solid content concentration in the ink is increased as in the example to improve the image density, the viscosity of the ink increases, and when used in inkjet recording, the ink ejection characteristics deteriorate. There is a point.

That is, according to the conventional method, it is difficult to finely disperse the pigment in the polymerizable unsaturated monomer, and the dispersion stability is insufficient. Then, according to the study of the present inventors, when the dispersion stability at the time of emulsifying the unsaturated monomer and the pigment was insufficient, the colored resin fine particles obtained by using these, The particle size distribution varies, resulting in insufficient storage stability and ejection stability.

Therefore, the object of the present invention is to obtain water resistance, weather resistance and
Colored resin fine particles useful as a coloring material for an ink that gives an image having light resistance and scratch resistance, is excellent in dispersion stability, and has a high pigment concentration and high color development, and efficiently obtains the colored resin fine particles. The manufacturing method is provided. Another object of the present invention is to provide an image having water resistance, weather resistance, light resistance, and scratch resistance, as well as excellent dispersion stability, and as a coloring material for an ink having a high pigment concentration and a high color forming property. Another object of the present invention is to provide a useful aqueous dispersion of colored resin fine particles and a method for efficiently producing the aqueous dispersion of colored resin fine particles. Another object of the present invention is to provide an image having water resistance, weather resistance, light resistance, and scratch resistance, and also has excellent dispersion stability. For example, ejection from a recording head when used in inkjet recording. An ink having excellent stability, and an ink jet recording apparatus, a recording unit and an ink cartridge using the ink,
The point is to provide an inkjet recording method.

[0010]

The above objects can be achieved by the present invention described below. That is, one embodiment of the present invention has a structure in which a pigment coated with a water-insoluble resin is encapsulated in a capsule containing at least a copolymer of a polymerizable unsaturated monomer and a reactive emulsifier. A colored resin fine particle is provided. Another aspect of the present invention is a step of emulsifying a pigment, a polymerizable unsaturated monomer, a reactive emulsifying agent and a polymerization initiator which are previously coated with a water-insoluble resin in an aqueous medium, And a step of polymerizing an unsaturated monomer, to provide a method for producing colored resin fine particles.

Another embodiment of the present invention has a structure in which a pigment coated with a water-insoluble resin is encapsulated in a capsule containing at least a copolymer of a polymerizable unsaturated monomer and a reactive emulsifier. Disclosed is an aqueous dispersion of colored resin fine particles, which comprises the colored resin fine particles contained therein in a dispersed state in an aqueous medium.

Another aspect of the present invention is to emulsify the polymerizable unsaturated monomer, the colorant, the emulsifier and the polymerization initiator in an aqueous medium, and polymerize the polymerizable unsaturated monomer. A method for producing colored resin fine particles, which comprises at least a step, wherein a phase inversion emulsification method is used in the emulsification step. Another aspect of the present invention provides colored resin fine particles obtained by the method for producing colored resin fine particles.

Another aspect of the present invention is to emulsify the polymerizable unsaturated monomer, the colorant, the emulsifier and the polymerization initiator in an aqueous medium, and polymerize the polymerizable unsaturated monomer. A method for producing an aqueous dispersion of colored resin fine particles, which comprises at least a step, wherein a phase inversion emulsification method is used in the emulsification step.

Another aspect of the present invention is an ink containing at least the colored resin fine particles or the colored resin fine particles obtained by the method for producing the colored resin fine particles, and a liquid medium. provide. Another aspect of the present invention is to provide a recording unit including an ink containing portion containing the ink for ink jet and a head portion for ejecting the ink. is there.

Another aspect of the present invention is to provide an ink cartridge comprising an ink containing portion containing the above-mentioned ink. Another aspect of the present invention provides an ink jet recording apparatus including an ink containing portion containing the ink for ink jet and a head portion for ejecting the ink. Is. Further, another aspect of the present invention provides an inkjet recording method, which comprises a step of ejecting the inkjet ink by an inkjet method.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to preferred embodiments. <First Aspect> In the colored resin fine particles according to an aspect of the present invention, a pigment coated with a water-insoluble resin is further encapsulated by a copolymer of a polymerizable unsaturated monomer and a reactive emulsifier. It has a generalized structure. And such colored resin fine particles are, for example, a step of emulsifying a pigment, a polymerizable unsaturated monomer, a reactive emulsifier and a polymerization initiator coated with a water-insoluble resin in an aqueous medium, and the polymerizable A step of polymerizing an unsaturated monomer,
Can be obtained by

According to the above aspect, since the pigment is coated with the non-water-soluble resin, the pigment surfaces do not come into direct contact with each other, and thus the pigment does not easily aggregate,
Further, when the water-insoluble resin is dissolved in the polymerizable unsaturated monomer, the pigment is easily dispersed in the polymerizable unsaturated monomer in a fine particle state to obtain a pigment dispersion having high dispersion stability. To be Then, by using the dispersion, it is possible to obtain the colored resin fine particles according to the present invention having high dispersion stability, excellent storage stability, and excellent dischargeability. Further, by using a pigment which is previously coated with a water-insoluble resin, it is not necessary to disperse the pigment in the polymerizable unsaturated monomer and / or water before emulsification or during emulsification. In addition to good productivity, the pigment is dispersed in a fine particle state, so the color developability is also very good, and colored resin fine particles with a high pigment concentration,
Also, an ink containing the fine particles can be easily obtained.

In order to produce the colored resin fine particles according to the embodiment of the present invention, as described above, at least the pigment previously coated with the water-insoluble resin, the polymerizable unsaturated monomer, the reactive emulsifier and the polymerization are used. Use an initiator. Each constituent element will be described below.

As the pigment previously coated with the water-insoluble resin, a so-called processed pigment can be used. Specifically, a color chip in which the pigment and the resin are kneaded under heating with two rolls or the like. (Taihei Chemical, Taisei Kako, etc.)
And commercially available processed pigments such as Microlith (manufactured by Ciba Specialty Chemicals Co., Ltd.) can be used. Further, a pigment obtained by any known method such as a simple coacervation method in which a pigment is dispersed in a resin solution and a poor solvent is added thereto to deposit the resin on the surface of the pigment can be used.

The pigment that can be used in the present invention is not particularly limited, but for example, the pigments described below are suitable. First, as the carbon black of the black pigment, carbon black produced by a furnace method or a channel method, having a primary particle size of 15 to 40 nm, a specific surface area by the BET method of 50 to 300 m ² / g, and a DBP oil absorption of 40.
What has a 150 ml / 100g, a volatile content of 0.5-10 mass%, and a pH value of 2-9 is preferable.

[0021] For example, as No.
2300, No. 900, MCF88, No. 40, N
o. 52, MA7, MA8, No. 2200B (above,
Mitsubishi Kasei), RAVEN1255 (Colombia),
REGAL400R, REGAL660R, MOGUL
L (above, made by Kyabot), Color Black
FW1, Color Black FW18, Col
or Black S170, Color Black
S150, Printex 35, Printex
Commercial products such as U (above, manufactured by Degussa) can be used. In addition, a new prototype may be used for the present invention.

Examples of yellow pigments include C.I. I.
Pigment Yellow 1, C.I. I. Pigm
ent Yellow 2, C.I. I. Pigment
Yellow 3, C.I. I. Pigment Yell
ow 13, C.I. I. Pigment Yellow
16, C.I. I. Pigment Yellow 83 and the like.

Examples of magenta pigments include C.I. I.
Pigment Red 5, C.I. I. Pigment
Red 7, C.I. I. Pigment Red 1
2, C.I. I. Pigment Red 48 (Ca),
C. I. Pigment Red 48 (Mn), C.I.
I. Pigment Red 57 (Ca), C.I. I.
Pigment Red 112, C.I. I. Pigme
nt Red 122, C.I. I. Pigment Vi
olet 19 and the like. As the magenta pigment, a quinacridone pigment is particularly preferable.

Examples of cyan pigments include C.I. I. P
igment Blue 1, C.I. I. Pigment
Blue 2, C.I. I. Pigment Blue
3, C.I. I. Pigment Blue 15: 3,
C. I. Pigment Blue 16, C.I. I. P
igment Blue 22, C.I. I. Vat Bl
ue 4, C.I. I. Vat Blue 6 etc. are mentioned. Further, with respect to the pigments of any of the above colors, those newly manufactured for the present invention can be used. As the cyan pigment, a metal phthalocyanine-based pigment is particularly preferable,
Copper phthalocyanine pigment is more preferable.

The water-insoluble resin coating the above-mentioned pigment is freely selected from the adsorptivity to the pigment used and the solubility to the polymerizable unsaturated monomer used, but especially vinyl chloride and vinyl acetate resins. , Vinyl chloride-vinyl acetate copolymer resin, polyvinyl resin such as polyvinyl acetal resin, cellulose resin and acrylic resin are preferable, and among them, vinyl chloride-vinyl acetate copolymer resin stabilizes the fine particles of the pigment in the polymerizable unsaturated monomer. Most suitable for doing. If desired, two or more water-insoluble resins may be used in combination.

The weight ratio of the pigment and the water-insoluble resin coating the pigment is preferably in the range of pigment / resin = 7/3 to 3/7,
It is more preferably 6/4 to 4/6. If there is a large amount of pigment, there is a concern that the pigment will aggregate in the polymerizable unsaturated monomer,
Further, when the amount of the resin is large, the pigment concentration in the colored resin fine particles becomes low depending on the amount of the unsaturated monomer used, and it becomes difficult to obtain a pigment ink having a high concentration.

Examples of the polymerizable unsaturated monomer include vinyl aromatic hydrocarbons, (meth) acrylic acid esters,
(Meth) acrylamide, alkyl-substituted (meth) acrylamide, N-substituted maleimide, maleic anhydride, (meth) acrylonitrile, methyl vinyl ketone, vinyl acetate, vinylidene chloride and the like can be mentioned.

Specific examples of vinyl aromatic hydrocarbons include:
For example, styrene, α-methylstyrene, o, m, p-
Examples thereof include chlorostyrene, p-ethylstyrene, and divinylbenzene, which may be used alone or in combination of two or more, but are not limited thereto.

Specific examples of the (meth) acrylic acid ester-based monomer include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, Methyl methacrylate, hexyl methacrylate,
2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-hydroxyacrylate,
Examples thereof include, but are not limited to, δ-hydroxyacrylate butyl, β-hydroxymethacrylic acid ethyl ester, ethylene glycol dimethacrylic acid ester, and tetraethylene glycol dimethacrylic acid ester.

These polymerizable unsaturated monomers may be used either individually or in combination of two or more. Of course,
In order to improve the properties of the obtained colored resin fine particles depending on the application, a small amount of a water-soluble monomer may be added and polymerized. As the water-soluble monomer, sulfonic acid group, phosphoric acid group,
Those having an anionic group such as a carboxylic acid group are mentioned, and these acids are alkali metal salts such as sodium salt,
It may be in the form of ammonium salt, amine salt or the like or in the form of free acid. Suitable examples thereof are styrene sulfonic acid, sodium styrene sulfonate, 2-acrylamido-2-methylpropene sulfonic acid, 2-hydroxymethyl methacryloyl phosphate, 3 -Chloro-2-hydroxypropyl methacryloyl phosphate, acrylic acid, methacrylic acid, fumaric acid, crotonic acid, tetrahydroterephthalic acid, itaconic acid, maleic acid and the like.

The emulsifier used in the present invention may be nonionic or anionic, or those containing both of them. Further, in order to reduce the free emulsifier to control the permeability of the ink and further improve the water resistance of the recorded image, it is preferable to use a reactive emulsifier.

The reactive emulsifier is an anionic or nonionic emulsifier having at least one unsaturated double bond in the molecule, and examples thereof include sulfosuccinic acid ester type and alkylphenol ether type. Examples of the nonionic reactive emulsifier include those having a polyoxyethylene group in the molecule. Specifically, "Adecaria Soap NE" (made by Asahi Denka Co., Ltd.) containing polyoxyethylene allyl glycidyl nonyl phenyl ether as the main component, "Aqualon RN" containing polyoxyethylene nonyl propenyl ether as the main component (Trade name: Dai-ichi Kogyo Seiyaku Co., Ltd.) and the like.

Examples of the anionic reactive emulsifier include sulfonic acid (salt) type, carboxylic acid (salt) type and phosphoric acid ester type. Specifically, "Adecaria Soap SE" (trade name, manufactured by Asahi Denka Co., Ltd.) containing sulfate ester salt of polyoxyethylene allyl glycidyl nonyl phenyl ether as a main component, sulfate ester salt of polyoxyethylene nonyl propenyl ether " Aqualon HS ",
"Aqualon BC" (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
Etc. In addition, as those having other structures, "Eleminol JS-2", "Eleminol RS-30" (trade name, manufactured by Sanyo Chemical Industry Co., Ltd.), "Latemul" (trade name, Kao Corporation)
Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and the like, but are not limited thereto.

These reactive emulsifiers may be used either individually or in combination of two or more, or may be used in combination with ordinary emulsifiers. The amount of such a reactive emulsifier used is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass, based on the mass of all the monomers.

As the polymerization initiator, a water-soluble or oil-soluble persulfate, a peroxide, an azo compound, a redox composition in which a peroxide and a reducing agent such as a sulfite are combined can be used. For example, ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxyl benzoate, 2,2-azobisisobutyronitrile, 2,2-azobis (2- Diaminopropane) hydrochloride,
2,2-azobis (2,4-dimethylvaleronitrile)
Etc.

The amount of such a polymerization initiator to be used is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, based on the mass of all the monomers. The colored resin fine particles according to this embodiment may contain additives such as an ultraviolet absorber, an antioxidant, or a color-developing improver, if necessary.

As an emulsifying method, an aqueous solution prepared by dispersing a pigment previously coated with a water-insoluble resin in a polymerizable unsaturated monomer and adding an emulsifier by a disperser such as a homomixer, a line mixer or a high pressure homogenizer is used. A direct emulsification method of emulsifying in a medium or a natural emulsification method of adding an emulsifier to a liquid in which a pigment previously coated with a non-water-soluble resin is dispersed in a polymerizable unsaturated monomer and adding this to a large amount of water is used. May be. Further, by using a phase inversion emulsification method in which a pigment previously coated with a water-insoluble resin is added to a liquid in which a polymerizable unsaturated monomer is dispersed, an emulsifier is added, and water is gradually added thereto while stirring, This is preferable because the dispersion has a more uniform particle size and a narrow particle size distribution.

The polymerization method may be either emulsion polymerization using a water-soluble polymerization initiator or suspension polymerization using an oil-soluble polymerization initiator. The average particle diameter of the colored resin fine particles obtained after the polymerization is preferably 500 nm or less, and more preferably 200 nm or less. By setting it within such a numerical range, sedimentation of the colored resin fine particles does not easily occur even when the ink is stored for a long period of time, and dispersion stability can be stably maintained for a long period of time. here,
The average particle diameter in the present invention is obtained by a cumulant analysis method in which the scattering intensity distribution resulting from fine particles detected by the dynamic light scattering method is applied to a normal distribution to calculate the average particle diameter.

<Second Embodiment> The colored resin fine particles according to the second embodiment of the present invention are (i) at least a polymerizable unsaturated monomer, a colorant, an emulsifier and a polymerization initiator emulsified in an aqueous medium. And (ii) a step of polymerizing the polymerizable unsaturated monomer, which is a method for producing colored resin fine particles, which is obtained by using a phase inversion emulsification method in the emulsification step. It has one characteristic.

The phase inversion emulsification method is a method in which water is gradually added to liquid oils containing an emulsifier while stirring.
When water droplets are added to oil, a W / O type emulsion is created first, and the viscosity increases as the amount of water increases, and eventually O / W
Phase inversion to type emulsion. The feature of the phase inversion emulsification method is that it passes through this phase inversion point. That is, by stirring with sufficient shearing force at the phase inversion point at which the particles and the continuous layer in which they are dispersed are replaced, it is possible to obtain an emulsion of uniform small particle size with a very narrow particle size distribution, The emulsion obtained by the phase inversion emulsification method is particularly excellent in stability.

The phase inversion emulsification method is generally carried out using a beaker and a stir bar, but in the present invention, stirring at the phase inversion point is carried out more strongly and uniformly to obtain more uniform and small particles. A disperser can also be used to obtain a diameter emulsion. Examples of the disperser include a three-one motor, a homomixer, and a homogenizer. By adding a mechanical dispersing force to the phase inversion emulsification method using such a disperser, the particle size distribution is narrow and the particle size is small, which has never been obtained, and the dispersion stability is particularly excellent. An emulsion can be obtained. In the method for producing colored resin fine particles according to the embodiment of the present invention, at least a polymerizable unsaturated monomer, a colorant, an emulsifier and a polymerization initiator are used, and a phase inversion emulsification method is used. Each constituent element will be described below.

(Polymerizable unsaturated monomer) As the polymerizable unsaturated monomer, the same ones as described in the first embodiment can be used.

(Colorant) As the colorant, those which can be dissolved or dispersed in the polymerizable unsaturated monomer are selected, and examples thereof include dyes, pigments and processed pigments. What is a processed pigment?
Addition of additional functions to ordinary pigment manufacturing processes, such as self-dispersion pigments in which at least one functional group is bonded directly or via other atomic groups to the pigment surface, pigments coated with pigment dispersants or resins, etc. Is a general term for products to which the process expected is added. In the present invention, pigments and processed pigments are preferably used because they have excellent weather resistance and light resistance. Further, when a pigment is used, in consideration of dispersibility in the polymerizable unsaturated monomer, it has adsorptivity for the pigment, and is a water-insoluble resin compatible with the polymerizable unsaturated monomer to be used in advance. It is particularly preferred to use coated pigments. The pigment that can be used in the present invention is not particularly limited, but for example, the pigments described below are suitable.

First, as the carbon black of the black pigment, carbon black produced by a furnace method or a channel method has a primary particle size of 15 to 40 mμm, a specific surface area by the BET method of 50 to 300 m ² / g, and a DBP oil absorption amount. 40-150 ml / 100g, volatile matter 0.5-10
Those having the characteristics of mass% and pH value of 2 to 9 are preferable.

Examples of such devices include No.
2300, No. 900, MCF88, No. 40, N
o. 52, MA7, MA8, No. 2200B (trade name or more, made by Mitsubishi Kasei), RAVEN1255 (product name made in Colombia), REGAL400R, REGAL660
R, MOGUL L (trade name or more, manufactured by KYABOT), C
color Black FW1, Color Blac
k FW18, Color Black S170, C
color Black S150, Printex 3
5, commercial products such as Printex U (trade name or more, manufactured by Degussa) can be used. In addition, a new prototype may be used for the present invention.

Examples of the yellow pigment include C.I. I.
Pigment Yellow 1, C.I. I. Pigm
ent Yellow 2, C.I. I. Pigment
Yellow 3, C.I. I. Pigment Yell
ow 12, C.I. I. Pigment Yellow
13, C.I. I. Pigment Yellow 16,
C. I. Pigment Yellow 17, C.I.
I. Pigment Yellow 55, C.I. I. P
igment Yellow 74, C.I. I. Pigm
ent Yellow 83, C.I. I. Pigment
Yellow 93, C.I. I. Pigment Yel
low 97, C.I. I. Pigment Yellow
98, C.I. I. Pigment Yellow 11
0, C.I. I. Pigment Yellow 128,
C. I. Pigment Yellow 138, C.I.
I. Pigment Yellow 139, C.I. I.
Pigment Yellow 147, C.I. I. Pi
gment Yellow 150, C.I. I. Pigme
nt Yellow 151, C.I. I. Pigment
Yellow 154, C.I. I. Pigment Y
ellow 155, C.I. I. Pigment Yel
low 180, C.I. I. Pigment Yellow
185 and the like.

Examples of magenta pigments include C.I. I.
Pigment Red 5, C.I. I. Pigment
Red 7, C.I. I. Pigment Red 1
2, C.I. I. Pigment Red 48 (Ca),
C. I. Pigment Red 48 (Mn), C.I.
I. Pigment Red 57 (Ca), C.I. I.
Pigment Red 112, C.I. I. Pigme
nt Red 122, C.I. I. Pigment Vi
olet 19 and the like. A quinacridone pigment is particularly preferable as the magenta pigment.

Examples of cyan pigments include C.I. I. P
igment Blue 1, C.I. I. Pigment
Blue 2, C.I. I. Pigment Blue
3, C.I. I. Pigment Blue 15: 3,
C. I. Pigment Blue 16, C.I. I. P
igment Blue 22, C.I. I. Vat Bl
ue 4, C.I. I. Vat Blue 6 etc. are mentioned. Phthalocyanine pigments are particularly preferable as the cyan pigment. Further, with respect to the coloring materials of any of the above colors, those newly manufactured for the present invention can be used.

The processed pigment that can be used in the present invention is selected to have dispersibility in the polymerizable unsaturated monomer used, for example, to improve the dispersibility in the polymerizable unsaturated monomer. Those subjected to the surface treatment of are preferably used.
Furthermore, when a pigment whose surface is preliminarily coated with a water-insoluble resin that is adsorptive to the pigment used in the first aspect and is compatible with the polymerizable unsaturated monomer is used, Since the increase in viscosity during the phase is suppressed, an ink excellent in high pigment concentration and color developability can be obtained, which is more preferable.

(Emulsifier) As the emulsifier, those similar to the emulsifier described in the first embodiment can be used. In order to perform stable emulsification and to have sufficient water resistance in the image formed by the ink containing the colored resin fine particles, the amount of the emulsifier used is 5 to 50 based on the weight of all monomers. It is preferably mass%, and further 1
0-40 mass% is preferable.

(Polymerization Initiator) As the polymerization initiator, the same initiators as those described in the first embodiment can be used, but the polymerization method is carried out by suspension polymerization in which the migration of monomers does not occur. Therefore, a polymerization initiator soluble in the monomer is preferably used. The amount of such a polymerization initiator used is preferably 0.01 to 10% by mass, and more preferably 0.05 to 5% by mass, based on the mass of all the monomers.

The colored resin fine particles according to this embodiment include
In addition to the polymerizable unsaturated monomer, the colorant, the emulsifier and the polymerization initiator, an additive such as an ultraviolet absorber, an antioxidant or a color improving agent may be added.

Next, the step of polymerizing the polymerizable unsaturated monomer according to this embodiment will be described. In the polymerization step, for example, an emulsion polymerization method using a pre-emulsification method and a suspension polymerization method can be used. The emulsion polymerization method and the suspension polymerization method are similar in that they use water as a medium, but the emulsion polymerization method uses a polymerization initiator insoluble in the monomer as a polymerization initiator, while,
The suspension polymerization method is different in that a monomer-soluble polymerization initiator is used. As a result, emulsion polymerization and suspension polymerization follow completely different polymerization mechanisms.

That is, in the suspension polymerization method, the polymerization proceeds in each monomer particle, whereas in the emulsion polymerization method, the polymerization is initiated in the micelle formed by the emulsifier in the system and a small amount of the monomer. Polymerization is initiated by the diffusion of the agent, and the monomer is supplied thereto from the monomer oil droplets to proceed with the polymerization. In the present invention, it is preferable to obtain colored resin fine particles by forming particles of a monomer containing a colorant by pre-emulsification using a phase inversion method, and polymerizing the particles while keeping the shape as it is. . Therefore, it is preferable to carry out the suspension polymerization method, which is a system in which the migration of the monomer from the monomer particles does not occur.

In the conventional suspension polymerization method, a stabilizer such as polyvinyl alcohol was added in order to keep the monomer in a stable dispersed state, and the polymerization was carried out while vigorously stirring to disperse the monomer. Therefore, it has been generally known that polydisperse particles having a larger particle diameter than emulsion polymerization can be obtained. However, when the method of the present invention is used, stable and uniform monomer particles having a small particle size can be formed by pre-emulsification using the phase inversion emulsification method, and thus particles obtained by suspension polymerization of the same can also be used. Stable and uniform small particle size.

The average particle size of the colored resin fine particles obtained after the polymerization is preferably 500 nm or less, more preferably 200 nm or less. Further, more preferably, the particle size distribution has a 10% cumulative value of 25 nm.
As described above, the 90% cumulative value is 1100 nm or less. Here, the average particle diameter in the present invention is obtained by the cumulant analysis method, in which the scattering intensity distribution due to the fine particles detected by the dynamic light scattering method is applied to the normal distribution to calculate the average particle diameter. .

The particle size distribution is obtained from the frequency distribution when the scattering intensity detected by the same measurement method is analyzed by the Marquart analysis method of the histogram method, and is 10% when the scattering intensity is accumulated from the small particle size side. And the particle size distribution of fine particles is calculated from the particle size at 90%. For these measurements, an apparatus capable of measuring the particle size distribution by a dynamic light scattering method such as an electrophoretic light scattering photometer ELS-8000 manufactured by Otsuka Electronics Co., Ltd. can be preferably used, and the above-mentioned analysis processing is performed by the attached software. Can be processed by.

When the average particle diameter and the particle size distribution are within the above ranges, the dispersion stability of the colored resin fine particles is improved, and even if the colored resin fine particles are stored for a long period of time in a low temperature and high temperature environment, the colored resin fine particles do not easily aggregate or settle. Further, when used as an ink for inkjet recording because the particle diameters are uniform, clogging in the inkjet device is small, and dischargeability is good. In order to form colored resin fine particles having an average particle diameter within the above range, the average particle diameter of the monomer particles after phase inversion emulsification is preferably 500 nm or less, more preferably 200 nm or less.

The colored resin fine particles obtained by the above-mentioned first and second aspects are those in which the colored resin fine particles are dispersed in an aqueous medium (in the present invention, this is referred to as an aqueous dispersion of colored resin fine particles). However, when an ink is produced using the colored resin fine particles according to the present invention, an aqueous dispersion of the colored resin fine particles may be used as it is, or depending on the composition of the ink to be obtained. , Water is removed from an aqueous dispersion of colored resin fine particles by a conventional method (for example, distillation, centrifugation, filtration, spray drying, etc.), and after taking out as colored resin fine particles, an appropriate solvent such as an aqueous medium or It may be dispersed in an oil medium again to form an ink.

The colored resin fine particles produced by the present invention have good water resistance, and the ink image obtained by using them has good weather resistance, light resistance and scratch resistance, and is excellent in dispersion stability. It can be suitably used as various recording inks. In particular, since it has good dispersibility in water, it is preferably used as an aqueous inkjet recording ink.

The ink using the colored resin fine particles of the present invention is composed of the colored resin fine particles held in an aqueous medium in a dispersed state. And it is preferable that at least water is contained as a constituent component of the aqueous medium. The proportion of water in the total mass of the ink is, for example, 20 to 95 mass%, particularly 4
It is preferably 0 to 95% by mass, more preferably 60 to 95% by mass.

Further, the aqueous medium may contain a water-soluble organic solvent. The amount of the water-soluble organic solvent used is 2 to 60% by mass based on the total mass of the ink. Specific water-soluble organic solvents include, for example, alkyl alcohols having 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol. , Amides such as dimethylformamide and dimethylacetamide, ketones such as acetone, ethers such as tetrahydrofuran and dioxane, polyalkylene glycols such as polyethylene glycol and polypropylene glycolicol, ethylene glycol, propylene glycol, butylene glycol, tris Alkylene groups such as ethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol and diethylene glycol have 2 to 6 carbon atoms. Lower alkyl ethers of polyhydric alcohols such as xylene glycols, glycerin, ethylene glycol monomethyl (or ethyl) ether, and diethylene glycol monomethyl (or ethyl) ether, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazo Examples thereof include cyclic amide compounds such as ridinone, sulfolane, dimethyl sulfoxide, 2-pyrrolidone and ε-caprolactam, and imide compounds such as succinimide.

The ink of the present invention is preferably used in an ink jet recording method for recording an image by ejecting the ink from the recording head by thermal energy or mechanical energy and attaching it to the recording medium. When the ink according to this aspect is particularly suitable for ink jet recording, the surface tension of the ink at 25 ° C. is 15 to 60 mN / m (dyn / cm),
Furthermore, 20-50 mN / m (dyn / cm), viscosity 1
5 cP (mPa · s) or less, especially 10 cP (mPa · s)
s) It is preferable to set it to the following. Further, the pH range is preferably 3 to 11, and more preferably 3.5 to 11.
It is 10.

Specific ink compositions that can achieve such characteristics include various inks used in the examples described later. In addition to the colored resin fine particles obtained as described above, various additives such as a surfactant, a pH adjusting agent and a mildew proofing agent may be added to the ink according to this embodiment. The recording medium used in the recording method using the ink according to this aspect is not particularly limited, and may be plain paper such as copy paper or bond paper, or a coat specially prepared for inkjet recording. Examples include paper, glossy paper, OHP film and the like.

The ink according to the present invention is particularly suitable for use in an ink jet recording system in which droplets are ejected by the action of heat energy for recording, but it can also be used as another ink jet recording method or a general writing tool. Needless to say. As a recording apparatus suitable for recording using the ink according to the present invention, thermal energy corresponding to a recording signal is applied to the ink in the chamber of the recording head,
A device that generates droplets by the energy is included.

An example of the structure of the recording head, which is the main part, is shown in FIGS. 1, 2 and 3. The head 13 is made of glass, ceramics, a plastic plate, or the like having a groove 14 through which ink passes, and a heating head 15 having a heating resistor used for heat-sensitive recording (a head is shown in the drawing, but is not limited to this. It is not a thing) and is obtained by adhering. The heating head 15 has a protective film 1 formed of silicon oxide or the like.
6, aluminum electrodes 17-1 and 17-2, a heating resistor layer 18 made of nichrome, a heat storage layer 19, and a substrate 20 having a good heat dissipation property such as alumina.

The ink 21 is a discharge orifice (fine hole).
22 is filled, and the meniscus 23 is generated by the pressure P.
Is formed. FIG. 4 shows an example of an ink jet recording apparatus incorporating the head as described above. In FIG. 4, 61 is a blade as a wiping member,
One end thereof is held by the blade holding member to become a fixed end, which is in the form of a cantilever. Blade 61
Is arranged at a position adjacent to the recording area of the recording head, and in the case of the example shown in FIG. 4, is held in a protruding form in the movement path of the recording head. Reference numeral 62 denotes a cap, which is disposed at a home position adjacent to the blade 61, and has a configuration in which it moves in a direction perpendicular to the moving direction of the recording head and comes into contact with the ejection surface to perform capping. Furthermore,
Reference numeral 63 denotes an ink absorber provided adjacent to the blade 61, and like the blade 61, is held in a form protruding in the moving path of the recording head.

The blade 61, the cap 62, and the absorber 63 constitute an ejection recovery unit 64. The ejection recovery unit 64 removes water, dust, and dust from the ink ejection port surface by the blade 61 and the absorber 63. Done. Reference numeral 65 denotes a recording head having ejection energy generating means for ejecting ink to a recording material facing the ejection port surface where the ejection ports are arranged to perform recording, and 66 denotes a recording head 65 in which the recording head 65 is mounted. It is a carriage for moving the. The carriage 66 slidably engages with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown). As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and its adjacent area.

Reference numeral 51 is a paper feed section for inserting a recording material, and 52 is a paper feed roller driven by a motor (not shown). With these configurations, the recording material is fed to a position facing the ejection opening surface of the recording head, and as recording progresses, the recording material is ejected to the ejection unit provided with the ejection roller 53. In the above-described configuration, when the recording head 65 returns to the home position after the recording is completed, the cap 62 of the ejection recovery unit 64 is retracted from the moving path of the recording head 65.
The blade 61 projects into the movement path. As a result,
The ejection port surface of the recording head 65 is wiped. When the cap 62 comes into contact with the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to project into the moving path of the recording head.

When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are in the same positions as the above wiping positions. As a result, even during this movement, the ejection port surface of the recording head 65 is wiped. The above-mentioned movement of the recording head to the home position is performed not only at the end of recording and at the time of ejection recovery, but also at the home position adjacent to the recording area at a predetermined interval while the recording head moves in the recording area for recording. Then, with this movement, the wiping is performed.

FIG. 5 is a sectional view showing an example of an ink cartridge 45 in which the head is provided with an ink supply member, for example, an ink storage portion which stores ink supplied via a tube. Here, reference numeral 40 is an ink containing portion containing the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into this stopper 42, the ink in the ink bag 40 can be supplied to the head. Reference numeral 44 is an ink absorber that receives waste ink.

The ink jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge are separated as described above, and the one in which they are integrated as shown in FIG. 6 is also preferable. Used. In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink containing portion containing ink, for example, an ink absorber is contained, and the ink in the ink absorber has a head portion having a plurality of orifices. The ink is ejected from 71 as an ink droplet. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the recording unit with the atmosphere. The recording unit 70 is used in place of the recording head 65 shown in FIG. 4, and is detachable from the carriage 66.

[0073]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist. Further, “%” or “part” in the text is based on mass unless otherwise specified.

Example 1 (Preparation of Aqueous Dispersion A of Fine Colored Resin Particles) Phthalocyanine blue (CI.PB15: 3) and chloride were added to a mixed solution of 4 parts of methyl methacrylate and 6 parts of n-butyl acrylate. Add 4 parts of processed pigment "Microlith Blue 4G-KP" (pigment concentration 50%: manufactured by Ciba Specialty Chemicals Co., Ltd.) composed of vinyl / vinyl acetate copolymer resin, stir with a stirrer and disperse the pigment. It was The average particle size of the pigment dispersed in the monomer was 135 nm. Next, 2 parts of a reactive emulsifier "Aqualon HS-20" (trade name, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as an emulsifier in the obtained dispersion liquid and 1,1-azobisisobutyronitrile as a polymerization initiator Mix 0.36 parts. Water was added to the above mixture and emulsified using a homogenizer. Water is further added to the obtained emulsion to prepare components other than water at 40%,
A dispersion in which the colored resin fine particles are dispersed in an aqueous medium (hereinafter referred to as “polymerization apparatus equipped with a stirrer, a reflux condenser and a nitrogen gas inflow pipe”, heated to 75 ° C. under a nitrogen stream and polymerized for 24 hours) , Which is referred to as a colored resin fine particle water dispersion).

Example 2 (Preparation of Aqueous Dispersion B of Colored Resin Fine Particles) The processed pigment was "Microlith Blue GA, which consisted of phthalocyanine blue (C.I.PB 15: 3) and polyvinyl butyral resin.
B "(trade name: pigment concentration 70%: manufactured by Ciba Specialty Chemicals Co., Ltd.), except that 2 parts were used to prepare an aqueous dispersion B of fine colored resin particles in the same manner as in Example 1. The average particle size of the pigment dispersed in the monomer was 156 nm.

Example 3 (Preparation of Aqueous Dispersion C of Colored Resin Fine Particles) The processed pigment was a hi-di color chip CB (trade name: pigment concentration) consisting of phthalocyanine blue (CI.PB15: 3) and a cellulose resin. 40%: Taihei Chemical Co., Ltd.) A colored resin fine particle water dispersion C was prepared in the same manner as in Example 1 except that 4 parts were used. The average particle size of the pigment dispersed in the monomer is 1
It was 65 nm.

Example 4 (Preparation of Aqueous Dispersion of Colored Resin Fine Particles D) The processed pigment was a hi-di color chip AC (trade name: pigment concentration) consisting of phthalocyanine blue (CI.PB15: 3) and an acrylic resin. 40%: Taihei Chemical Co., Ltd.) A colored resin fine particle water dispersion D was prepared in the same manner as in Example 1 except that 4 parts were used. The average particle size of the pigment dispersed in the monomer is 17
It was 3 nm.

Example 5 (Preparation of Aqueous Dispersion E of Fine Colored Resin Particles) A solution prepared by dissolving 5 parts of vinyl chloride / vinyl acetate copolymer resin VYHH (trade name, manufactured by Union Carbide Co.) in 90 parts of dimethylformamide (DMF). Phthalocyanine blue (C.I.PB1
5: 3) 5 parts were added and dispersed by a sand mill. The average particle size of the dispersed pigment was 140 nm. Next, 270 parts of methanol was gradually added to this dispersion while stirring to aggregate the resin-coated pigment, which was collected by filtration and dried under reduced pressure to prepare a resin-coated pigment.

4 parts of the resin-coated pigment obtained above was added to a mixed solution of 4 parts of styrene and 6 parts of 2-ethylhexyl acrylate, and the mixture was stirred with a stirrer to disperse the pigment. The average particle size of the pigment dispersed in the monomer was 144 nm.
Reactive emulsifier "Eleminol JS-2" as emulsifier
2 parts (trade name, manufactured by Sanyo Kasei Co., Ltd.) and 0.36 parts of 1,1-azobisisobutyronitrile as a polymerization initiator were mixed, water was added to the above mixture, and the mixture was emulsified using a homogenizer.

Water was further added to the obtained emulsion to adjust the content of components other than water to 40%, and the emulsion was placed in a polymerization apparatus equipped with a stirrer, a reflux condenser and a nitrogen gas inflow tube, and a nitrogen stream was introduced. The temperature was raised to 75 ° C. and polymerization was carried out for 24 hours to obtain an aqueous dispersion E of fine colored resin particles.

Comparative Example 1 A polymer dispersant Di was added to a mixed solution of 4 parts of methyl methacrylate and 6 parts of n-butyl acrylate.
2 parts of phthalocyanine blue (C.I.PB15: 3) and 10 parts of glass beads having a diameter of 0.5 mm were dissolved in a solution prepared by dissolving 2 parts of sperbyk 161 (trade name, manufactured by BYK Japan KK) in terms of solid content. In addition, the same pigment concentration as in Example 1 was used, and dispersion with a sand mill was tried. However, at this concentration, the viscosity was too high, and the dispersion adhered to the inner wall and the lid of the vessel of the sand mill, and the dispersion was not satisfactory.

Comparative Example 2 (Preparation of Aqueous Dispersion F of Fine Colored Resin Particles) A polymer dispersant Disperbyk 161 (trade name: Big Chem. Ltd.) was added to a mixed solution of 4 parts of methyl methacrylate and 6 parts of n-butyl acrylate.
Phthalocyanine blue (C.I.PB15: 3) 1 was added to a solution prepared by dissolving 1 part of Japan Co., Ltd. in terms of solid content.
Parts, and 10 parts of glass beads having a diameter of 0.5 mm were added, and dispersed by a sand mill for 16 hours. The average particle size of the pigment dispersed in the monomer was 350 nm. Emulsification and polymerization were carried out in the same manner as in Example 1 except that this dispersion liquid was used to obtain an aqueous dispersion F of fine colored resin particles.

<Evaluation> Each of the colored resin fine particle water dispersions A to F obtained in the above Examples and Comparative Examples was evaluated by the following methods and criteria. The obtained results are shown in Table 1.

(Average Particle Size) The average particle size of each of the colored resin fine particle water dispersions A to F was measured by a dynamic light scattering measuring device (trade name: ELS-8000, manufactured by Otsuka Electronics Co., Ltd.). The liquid temperature was measured at 25 ° C. The average particle size was obtained from the scattering intensity by the cumulant analysis method using the attached software.

(Storage Stability) Each of the colored resin fine particle water dispersions A to F was placed in a container coated with a fluororesin and sealed, and stored at 5 ° C. and 60 ° C. for 1 month, to thereby cause gelation or sedimentation. The presence or absence of the sample was visually observed and evaluated. The evaluation results are classified as follows. A: Almost no gelation or sedimentation. B: A slight gelation or precipitate was observed, but there was no problem in practice. C: Gelation and sediment are severe.

[0086]

Examples 6 to 10 and Comparative Example 3 (Preparation of ink) 5 parts of glycerin, 5 parts of ethylene glycol, 5 parts of trimethylolpropane, acetylenol E
50 parts of each of the colored resin fine particle water dispersions A to F obtained above are added to 1 part of H and 34 parts of water and stirred.
Further, this was filtered to obtain the inks of Examples 6 to 10 and the ink of Comparative Example 3.

<Evaluation> The inks of Examples 6 to 10 and the inks of Comparative Example 3 obtained above were evaluated by the following methods and criteria. The obtained results are shown in Table 2.

(Storage Stability) Each ink was placed in a container coated with a fluororesin, sealed, and stored at 5 ° C. and 60 ° C. for 1 month, and the presence or absence of gelation or sediment was visually evaluated. The evaluation results are classified as follows. A: Almost no gelation or sedimentation. B: A slight gelation or precipitate was observed, but there was no problem in practice. C: Gelation and sediment are severe.

(Discharge Stability) The ink tanks of the BJ cartridge BC-21 mounted on a color BJ printer (trade name: BJC-420J; manufactured by Canon Inc.) were filled with the obtained 6 kinds of ink. , Set this cartridge to BJC-420J,
Printing was performed on plain paper (360 x 360 dpi, HQ mode) on recording paper (Pro Photo Photo Paper PR-101; manufactured by Canon Inc.). Then, a 1-dot vertical line was printed on the recording paper at the beginning of using the BC-21 cartridge.
Further, the text was printed until the BC-21 cartridge was used up, and a vertical line of 1 dot was printed on another recording paper using the cartridge just before the use. These recording papers were visually observed from a distance of 25 cm, and the print result by the cartridge at the beginning of use and the print result by the cartridge at the end of the use were compared and evaluated according to the following criteria.

A: There is no difference between the two. B: Although a dot landing deviation is recognized in a part of the vertical line printed by the cartridge just before the end of use, it can be recognized as a straight line. C: The dot landing deviation is clearly recognized on the vertical line printed by the cartridge just before the end of use, and the vertical line is misaligned.

(Image Density) After printing a solid image for 12 hours, the image density was measured using a reflection densitometer Macbeth RD-918 (manufactured by Macbeth Co.), and the evaluation results were classified as follows. A: Image density of 1.50 or higher. B: Image density 1.31 to 1.49. C: Image density 1.30 or less.

(Water resistance) First, after solid images were printed using the obtained 6 kinds of inks and left for 24 hours, the image densities were measured using a reflection densitometer Macbeth RD-918 (manufactured by Macbeth). To do. Next, put this printed matter in tap water 5
After leaving it for a minute and drying the water, the reflection density was measured, and the residual ratio of the reflection density before the water resistance test and after the water resistance test was obtained and used as a scale for water resistance evaluation. The evaluation results are classified as follows. A: The residual ratio of image density is 80% or more. B: The residual ratio of image density is 70% or more and less than 80%. C: The residual ratio of image density is less than 70%.

(Scratch resistance) 12 hours after a solid image was printed using the obtained 6 kinds of ink, sillbon paper was placed on the printed paper, and one side of 5c
After placing a weight of 1 m and a weight of 1 kg, when the sillbon paper is pulled, visually observe whether the non-printed part (white part) of the recording paper and the sillbon paper are stained by rubbing of the printed part. Then, the following criteria were evaluated. A: No stain on the white part and sillbon paper. B: Silbon paper only has stains. C: Both white part and sillbon paper are stained.

[0095]

Example 11 (Preparation of Aqueous Dispersion G of Fine Colored Resin Particles) As a polymerizable unsaturated monomer, 4 parts of methyl methacrylate and n-acrylic acid were used.
A mixture of 6 parts of butyl was used, to which the polymeric dispersant Dis
phthalocyanine blue (C.I.PB15: as a colorant) was dissolved in a solution in which 1 part of perbyk161 (trade name, manufactured by BYK-Chem Japan Co., Ltd.) was dissolved in terms of solid content.
3) 1 part, and further 10 glass beads with a diameter of 0.5 mm.
Add a part and disperse in a sand mill for 16 hours. After removing the glass beads, 2 parts of a reactive emulsifier "Eleminol JS-2" (trade name, manufactured by Sanyo Chemical Industry Co., Ltd.) as an emulsifier and 0.36 part of 2,2-azobisisobutyronitrile as a polymerization initiator To mix.

Water was gradually added to the above mixture with stirring with a glass rod, and when the viscosity was increased, the mixture was further stirred with a glass rod. The mixture is sufficiently stirred at the phase inversion point, and water is further added to invert the phase to obtain an emulsion. Water is further added to the obtained emulsion to adjust the content of components other than water to 20%, and the mixture is placed in a polymerization device (a polymerization device equipped with a stirrer, a reflux condenser and a nitrogen gas inflow pipe), and nitrogen is added. 24 in a stream of air
Polymerization was carried out for a time to obtain an aqueous dispersion G of fine colored resin particles.

[Example 12] (Preparation of aqueous dispersion H of fine colored resin particles) 4 parts of styrene and 6 parts of n-butyl acrylate as the polymerizable unsaturated monomer,
Processed pigment "MI consisting of phthalocyanine blue (15: 3) as a colorant and a vinyl chloride-vinyl acetate copolymer"
CROLITH Blue4GKP "(trade name: pigment concentration 50%: manufactured by Ciba Specialty Chemicals Co., Ltd.)
1 part, reactive emulsifier "Eleminol JS-" as an emulsifier
2 "(trade name, manufactured by Sanyo Chemical Industry Co., Ltd.), and 2,2-azobisisobutyronitrile 0.3 as a polymerization initiator.
These are mixed using 6 parts.

Water was gradually added to the above mixture while stirring with a glass rod, and when the viscosity was increased, the mixture was further vigorously stirred with a glass rod. The mixture is sufficiently stirred at the phase inversion point, water is further added thereto, and the phase is inverted to obtain an emulsion. Polymerization was carried out in the same manner as in Example 1 using the obtained emulsion to give an aqueous dispersion H of fine colored resin particles.
Got

Example 13 (Preparation of Aqueous Dispersion I of Fine Colored Resin Particles) 4 parts of methyl methacrylate and 6 parts of n-butyl acrylate as the polymerizable unsaturated monomer, and phthalocyanine blue (C.I.
I. PB15: 3) and a processed pigment "MICROLITH Blue 4" composed of a copolymer of vinyl chloride and vinyl acetate.
GKP "(brand name pigment concentration 50%: Ciba Specialty Chemicals Co., Ltd.) 1 part, reactive emulsifier" Adecaria Soap SE-10N "(trade name Asahi Denka Co., Ltd.) as an emulsifier and polymerization 0.36 parts of 2,2-azobisisobutyronitrile is used as an initiator and they are mixed.

Water was gradually added to the above mixture with stirring with a homomixer, and when the viscosity increased, the number of revolutions was increased and the mixture was further stirred. The mixture is sufficiently stirred at the phase inversion point, water is further added thereto, and the phase is inverted to obtain an emulsion. Polymerization was performed using the obtained emulsion in the same manner as in Example 1 to obtain an aqueous dispersion I of fine colored resin particles.

Example 14 Preparation of Aqueous Dispersion J of Fine Colored Resin Particles 4 parts of methyl methacrylate and acrylic acid-2-as the polymerizable unsaturated monomer.
6 parts of ethylhexyl, reactive emulsifier "Aqualon HS-20" (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as an emulsifier 2
Emulsification and polymerization were carried out in the same manner as in Example 11 except that the parts were used to obtain colored resin fine particle water dispersion J.

Comparative Example 4 (Preparation of Aqueous Dispersion K of Fine Colored Resin Particles) A mixture of 4 parts of methyl methacrylate and 6 parts of n-butyl acrylate was used as the polymerizable unsaturated monomer, and a polymer dispersion was prepared. Agent "Dis
perbyk 161 "(trade name, manufactured by Big Chem Japan Co., Ltd.) is dissolved in a solution in which 1 part by solid amount is dissolved, and phthalocyanine blue (CI.PB15:
3) Add 1 part and 10 parts of glass beads having a diameter of 0.5 mm, and disperse in a sand mill for 16 hours. After removing the glass beads, 0.36 part of 2,2-azobisisobutyronitrile as a polymerization initiator is mixed.

As an emulsifier, 2 parts of a reactive emulsifier "Eleminol JS-2" (trade name, manufactured by Sanyo Chemical Industry Co., Ltd.) was added to 5 parts of water.
The above colorant solution is added to what is dissolved in 3.44 parts, and the mixture is stirred with a homomixer to obtain an emulsion. The obtained emulsion is placed in a polymerization device (a polymerization device equipped with a stirrer, a reflux condenser and a nitrogen gas inflow pipe), heated to 75 ° C. under a nitrogen stream and polymerized for 24 hours to disperse the colored resin fine particles in water. I got body K.

<Evaluation> Each of the colored resin fine particle water dispersions G to K obtained in the above Examples and Comparative Examples was evaluated by the following methods and criteria. The obtained results are shown in Table 3.

(Average Particle Diameter) The average particle diameter of each colored resin fine particle water dispersion was measured by a dynamic light scattering method (trade name: ELS-8000, manufactured by Otsuka Electronics Co., Ltd.).
The liquid temperature was measured at 25 ° C. The average particle size was obtained from the scattering intensity by the cumulant analysis method using the attached software. Similarly, the particle size distribution is 1 when the frequency distribution of the scattering intensity is obtained from the scattering intensity by the Marquadt analysis method of the histogram method and the scattering intensity is accumulated from the small particle size side.
The particle diameters at 0% and 90% were obtained.

(Storage Stability) Each aqueous dispersion of colored resin fine particles was placed in a container coated with a fluororesin, sealed, and stored at 5 ° C. and 60 ° C. for 1 month to check for gelation and sedimentation. It was visually observed and evaluated according to the following criteria. The evaluation results are classified as follows. A: Almost no gelation or sedimentation. B: A slight gelation or precipitate was observed, but there was no problem in practice. C: Gelation and sediment are severe.

[0108]

[Examples 15 to 18 and Comparative Example 5] (Preparation of Ink) The inks of Examples 15 to 18 were prepared using the aqueous dispersions of fine colored resin particles G to J. To 10 parts of glycerin, 5 parts of ethylene glycol, 5 parts of trimethylolpropane, 1 part of acetylenol EH and 54 parts of water, the colored resin fine particle water dispersions G to J obtained above as coloring materials are added.
25 parts of each was added and stirred. Further, this was filtered to obtain each ink of Examples 15-18. Example 15-
An ink of Comparative Example 5 was obtained in the same manner as in 18, using the colored resin fine particle water dispersion K.

<Evaluation> Examples 15 to 18 obtained above
And each ink of Comparative Example 5 was evaluated by the following methods and criteria. The obtained results are shown in Table 4.

(Storage stability) Each ink was placed in a container coated with a fluororesin, sealed, and kept at 5 ° C. and 60 ° C.
The sample was stored for 1 month and visually evaluated for the presence of gelation and sediment. The evaluation results are classified as follows. A: Almost no gelation or sedimentation. B: A slight gelation or precipitate was observed, but there was no problem in practice. C: Gelation and sediment are severe.

(Discharge Stability) A color BJ printer (trade name: BJC-420J; manufactured by Canon Inc.) was used for each of the five inks of Examples 15 to 18 and Comparative Example 5.
The ink tank of the BJ cartridge BC-21 installed in the BJC-420J is filled with this cartridge.
BJC-420J plain paper, 360 x 3
Printing was performed on recording paper (BJ-electrophotographic co-paper Canon PB paper; manufactured by Canon Inc.) in HQ mode at 60 dpi. First of all, to start using the BC-21 cartridge 1
A vertical line of dots was printed on the recording paper. And BC-2
Text is printed until one cartridge is used up,
A vertical line of 1 dot was printed on another recording paper using the cartridge just before use.

These recording papers were visually observed from a distance of 25 cm, and the print result by the cartridge at the beginning of use and the print result by the cartridge at the end of the use were compared and evaluated according to the following criteria. A: There is no difference between the two. B: Although a dot landing deviation is recognized in a part of the vertical line printed by the cartridge just before the end of use, it can be recognized as a straight line. C: The dot landing deviation is clearly recognized on the vertical line printed by the cartridge just before the end of use, and the vertical line is misaligned.

(Water resistance) A solid image was printed using each of the obtained inks, allowed to stand for 24 hours, and then measured using a reflection densitometer Macbeth RD-918 (manufactured by Macbeth). The printed matter was allowed to stand in tap water for 5 minutes, the water was dried to measure the reflection density, and the residual ratio of the reflection density before the water resistance test and after the water resistance test was obtained and used as a scale of water resistance. The evaluation results are classified as follows. A: The residual ratio of image density is 80% or more. B: The residual ratio of image density is 70% or more and less than 80%. C: The residual ratio of image density is less than 70%.

(Scratch resistance) 12 hours after a solid image was printed using each of the obtained inks, sillbon paper was placed on the printed paper, and one side was 5 cm and the weight was 1
After placing the kg weight, when pulling the sillbon paper, visually observe whether the non-printed part (white part) of the recording paper and the sillbon paper are stained by rubbing of the printed part,
The following criteria evaluated. A: There is no stain on the white part and the sillbon paper. B: Only the sillbon paper is stained. C: There are stains on both the white part and the sillbon paper.

[0116]

[0117]

As described above, according to the present invention,
Gives images with water resistance, weather resistance, light resistance, and scratch resistance,
Also provided are colored resin fine particles which are excellent in dispersion stability and are useful as a coloring material for ink having a high pigment concentration and high color development, and a production method capable of efficiently producing the same. Further, according to the present invention, an image having water resistance, weather resistance, light resistance, and scratch resistance is provided, and dispersion stability is excellent, and particularly ejection stability from a recording head when used in inkjet recording. Also provided are an excellent ink, an inkjet recording apparatus using the ink, a recording unit and an ink cartridge, and an inkjet recording method.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a head portion of an inkjet recording apparatus.

FIG. 2 is a cross-sectional view of a head portion of an inkjet recording device.

FIG. 3 is an external perspective view of a head portion of the inkjet recording apparatus.

FIG. 4 is a perspective view showing an example of an inkjet recording apparatus.

FIG. 5 is a vertical sectional view of an ink cartridge.

FIG. 6 is a perspective view of a recording unit.

[Explanation of symbols]

13: Head 14: groove 15: Heating head 16: Protective film 17-1, 17-2: Aluminum electrodes 18: Heating resistor layer 19: Heat storage layer 20: substrate 21: Ink 22: Discharge orifice (fine hole) 23: Meniscus 25: Recording material 28: Heating head 40: Ink bag 42: Stopper 44: Ink absorber 45: Ink cartridge 51: Paper feed section 52: Paper feed roller 53: Paper ejection roller 61: Wiping member 62: Cap 63: Ink absorber 64: Discharge recovery unit 65: recording head 66: Carriage 67: Guide shaft 68: Motor 69: Drive belt 70: Recording unit 71: Head part 72: Air communication port

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 11/00 C09D 17/00 17/00 B41J 3/04 101Y (72) Inventor Masaaki Hiro 3rd Shimomaruko, Ota-ku, Tokyo No. 30-2 Canon Inc. (72) Inventor Katsushi Danjo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Makiko Endo 3-30-2 Shimomaruko, Ota-ku, Tokyo No.Canon F-term (reference) 2C056 EA13 FC02 2H086 BA53 BA54 BA55 BA59 4J037 AA02 AA30 CA08 CC01 CC14 CC15 CC16 DD19 DD24 EE03 EE06 EE11 EE12 EE28 EE43 FF23 4J039 AB02 AD05 AD08 AD10 BA04 BC60 CA03 BD03 BE03 EA36 EA38 EA44 GA24

Claims (37)

[Claims] 1. A pigment coated with a water-insoluble resin has a structure of being encapsulated in a capsule containing at least a copolymer of a polymerizable unsaturated monomer and a reactive emulsifier. Colored resin fine particles characterized by: 2. The colored resin fine particles according to claim 1, wherein the water-insoluble resin is at least one resin selected from the group consisting of vinyl resins, cellulose resins and acrylic resins. 3. The colored resin fine particles according to claim 2, wherein the vinyl resin is a vinyl chloride-vinyl acetate copolymer resin. 4. The colored resin fine particles according to claim 1, wherein the pigment is a metal phthalocyanine. 5. A step of emulsifying a pigment, a polymerizable unsaturated monomer, a reactive emulsifier and a polymerization initiator, which have been previously coated with a water-insoluble resin, in an aqueous medium, and the above polymerizable unsaturated monomer. And at least a step of polymerizing the same. 6. The method according to claim 5, wherein the pigment, the reactive emulsifier and the polymerization initiator, which have been previously coated with a water-insoluble resin, are dispersed in a polymerizable unsaturated monomer, and the dispersion is emulsified in an aqueous medium. A method for producing the colored resin fine particles described. 7. The method for producing colored resin fine particles according to claim 5, wherein the water-insoluble resin is at least one resin selected from the group consisting of vinyl resins, cellulose resins and acrylic resins. 8. The method for producing colored resin fine particles according to claim 7, wherein the vinyl resin is a vinyl chloride-vinyl acetate copolymer resin. 9. The method for producing colored resin fine particles according to claim 5, wherein the pigment is a metal phthalocyanine. 10. A colored resin fine particle having a structure in which a pigment coated with a water-insoluble resin is encapsulated in a capsule containing at least a copolymer of a polymerizable unsaturated monomer and a reactive emulsifying agent, in an aqueous medium. An aqueous dispersion of colored resin fine particles, characterized in that it is contained in a dispersed state. 11. An ink containing at least the colored resin fine particles according to any one of claims 1 to 4 and a liquid medium. 12. The ink according to claim 11, wherein the ink is an inkjet recording ink. 13. Colored resin fine particles having at least a step of emulsifying a polymerizable unsaturated monomer, a colorant, an emulsifier and a polymerization initiator in an aqueous medium, and a step of polymerizing the polymerizable unsaturated monomer. A method for producing colored resin fine particles, which comprises using a phase inversion emulsification method in the emulsification step. 14. The method for producing colored resin fine particles according to claim 13, wherein the emulsifier is a reactive emulsifier, and the method has a step of polymerizing the reactive emulsifier. 15. The method for producing colored resin fine particles according to claim 14, which has a step of copolymerizing the reactive emulsifier with a polymerizable unsaturated monomer. 16. The method for producing colored resin fine particles according to claim 14, wherein the reactive emulsifier is contained in an amount of 5 to 50% by mass based on the polymerizable unsaturated monomer. 17. The colorant according to claim 13, which is a pigment.
7. The method for producing colored resin fine particles according to any one of 6 above. 18. The method for producing colored resin fine particles according to claim 13, wherein the colorant is compatible with the polymerizable unsaturated monomer. 19. The method for producing colored resin fine particles according to claim 13, wherein the colorant is a pigment previously coated with a water-insoluble resin. 20. The method for producing colored resin fine particles according to claim 19, wherein the water-insoluble resin is at least one resin selected from the group consisting of vinyl resins, cellulose resins and acrylic resins. 21. The method for producing colored resin fine particles according to claim 19, wherein the water-insoluble resin is a vinyl chloride-vinyl acetate resin. 22. The method for producing colored resin fine particles according to claim 13, wherein the polymerization initiator is an oil-soluble polymerization initiator that is soluble in the polymerizable unsaturated monomer. 23. The method for producing colored resin fine particles according to claim 22, wherein a suspension polymerization method is used in the polymerization step. 24. Colored resin fine particles obtained by the method for producing colored resin fine particles according to any one of claims 5 to 9 and 13 to 23. 25. An ink containing at least the colored resin fine particles according to claim 24 and a liquid medium. 26. The ink according to claim 25, wherein the liquid medium is aqueous. 27. The ink according to claim 25, wherein the liquid medium is oily. 28. The ink jet recording is used.
The ink according to any one of 5 to 27. 29. Colored resin fine particles having at least a step of emulsifying a polymerizable unsaturated monomer, a colorant, an emulsifier and a polymerization initiator in an aqueous medium, and a step of polymerizing the polymerizable unsaturated monomer. A method for producing a water dispersion, wherein a phase inversion emulsification method is used in the emulsification step, which is a method for producing an aqueous dispersion of colored resin fine particles. 30. A recording unit comprising an ink containing portion containing the ink according to claim 12 and a head portion for ejecting the ink. 31. An ink cartridge comprising an ink containing portion containing the ink according to claim 11 or 12. 32. An ink jet recording apparatus comprising: an ink containing section containing the ink according to claim 12; and a head section for ejecting the ink. 33. An ink jet recording method comprising a step of ejecting the ink according to claim 12 by an ink jet method. 34. A recording unit comprising an ink containing portion containing the ink according to claim 28 and a head portion for ejecting the ink. 35. An ink cartridge comprising an ink containing portion containing the ink according to any one of claims 25 to 28. 36. An ink jet recording apparatus comprising an ink containing portion containing the ink according to claim 28 and a head portion for ejecting the ink. 37. An ink jet recording method comprising a step of ejecting the ink according to claim 28 by an ink jet method.