JPH05273792A - Wet toner and its production - Google Patents

Abstract

PURPOSE:To improve printing durability, transfer property and resolution by precipitating resin particles of submicron-order particle size with a narrow distribution of the particle size. CONSTITUTION:This toner consists of a single material of olefin resin particles having carboxyl groups or ester groups or olefin resin particles with addition of a coloring agent, and a large parts of liquid aliphatic hydrocarbons. An the toner consists of polyhydroxy carboxylic acid ester of a trimer to decamer of hydroxy carboxylic acid ester as a monomer. The toner is produced by the following process. A single material of an olefin resin or an olefin resin with addition of a coloring agent is dissolved by heating in a solvent high in temp. dependency of solubility for the resin. The obtd. resin soln. is introduced to a liquid aliphatic hydrocarbon in the presence of polyhydroxy carboxylic acid ester of a trimer to decamer of hydroxy carboxylic acid ester as a monomer, and then cooled to precipitate resin particles while the solvent is substituted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet toner and a method for producing the same, and more particularly to a wet toner obtained by dispersing olefin resin particles having a carboxyl group or an ester group in an electrically insulating liquid for electrophotography. , A wet toner suitable for electrostatic printing and information recording, and a method for producing the same.

[0002]

2. Description of the Related Art For example, a method of forming an image portion of a lithographic printing plate using an electrophotographic method is well known in the field of light printing. This method generally involves charging a zinc oxide master paper prepared by coating a photoconductive zinc oxide powder with a binder resin on the surface of a conductive treated paper, exposing it to an image, developing it with an electrophotographic toner, and then fixing it. Further, it is a method of obtaining a lithographic printing plate by further subjecting the non-image area to hydrophilic treatment.

Conventionally, the wet toner used as this kind of electrophotographic toner is composed of an electrically insulating liquid and colorant particles having a particle diameter of 0.1 to 1 μm dispersed therein, and is contained in the electrically insulating liquid. A resin in which a resin for the purpose of dispersing, fixing and controlling charge of colorant particles is dissolved is used.

This type of wet toner has the advantage that it has excellent resolution due to its small particle size, but since the fixing of the toner is due to the dry fixation of the resin dissolved in the solvent, the adhesion to the printing plate substrate is poor. Moreover, since the image area itself has a small cohesive force, the image area of the printing plate is easily removed during printing, and the printing durability is weak.

The present inventor uses an olefin resin having a carboxyl group or an ester group as a resin, heat-dissolves it in a solvent having a high temperature dependence in solubility to the resin to prepare a resin solution, and then the resin solution The resin particles are cooled to precipitate the resin particles to obtain a wet type toner, whereby the resin particles having a narrow particle size distribution can be obtained. As a result, the wet type toner has excellent printing durability, transferability, and good resolution. It was found that the toner can be used as a toner, and the application was filed earlier. However, there is a demand for a wet toner composed of resin particles having a narrower particle size distribution.

An object of the present invention is to provide a wet type toner which can make the precipitated resin particles in a submicron unit and have a narrower particle size distribution, and a manufacturing method thereof.

[0007]

The wet toner of the present invention comprises:
In a wet toner comprising olefin resin (hereinafter simply referred to as olefin resin) particles having a carboxyl group or an ester group alone, or olefin resin particles to which a colorant is added and most of liquid aliphatic hydrocarbons, hydroxycarboxylic The present invention is characterized in that a 3- to 10-mer polyhydroxycarboxylic acid ester having an acid ester as a monomer is present.

Further, the method for producing a wet toner is as follows. The olefin resin alone or the olefin resin added with a colorant is heated and dissolved in a solvent having a high temperature dependency in the solubility of the resin to prepare a resin solution. The resin solution is charged into a liquid aliphatic hydrocarbon in the presence of a 3- to 10-mer polyhydroxycarboxylic acid ester having a hydroxycarboxylic acid monomer as a monomer and cooled to precipitate resin particles, and a solvent is added. It is characterized in that it is substituted with the aliphatic hydrocarbon.

The present invention will be described in detail below.

The olefin resin is preferably an ethylene-vinyl acetate copolymer. As the ethylene-vinyl acetate copolymer, Toyo Soda Industry Co., Ltd.
Ultrasen series manufactured by, for example, 510X, 515F, 53
0,537,537L, 537S, 525,520F, 540,540F, 541,541L, 625,63
0,630F, 682,627,631,633,680,681,635,634,710,720,72
Sumitomo Chemical Co., Ltd.'s Sumitate series such as 2,725,751,750,760 etc., such as DD-10, HA-20, HC-10, HE-10, KA-10,
KA-20, KA-31, KC-10, KE-10, MB-11, RB-11 etc. Evaflex series manufactured by Mitsui DuPont Chemicals Co., Ltd., for example
45X, YW, 150,210,220,250,260,310,360,410,420,450,46
0,550,560 etc., Soagoren series manufactured by Nippon Gohsei Co., Ltd., for example, BH, CH, CI, DH etc. Soarex series,
For example, RBH, RCH, RDH, etc., Dumilan series of Takeda Pharmaceutical Co., Ltd., such as Dumilan D-219, D-229, D-251
S, C-2280, C-2270, C-1590, C-1570, C-1550 and the like can be mentioned. Further, Yucaron-Eva manufactured by Mitsubishi Petrochemical Co., Ltd., Elpax manufactured by DuPont, USA and the like can be used.

In addition, a product obtained by modifying a polyolefin resin to introduce a carboxyl group, an example of which is a product name,
N-Polymer made by Nippon Petrochemical Co., Ltd., Tonen Petrochemical Co., Ltd.
Tonen CMP-HA series, Mitsubishi Yuka Co., Ltd. MOD
IC, Steel Manufacturing Co., Ltd. Saixen, Mitsui Toatsu Chemical
Ronply Co., Ltd., Mitsui Petrochemical Co., Ltd. Admer, etc., a copolymer of ethylene and acrylic acid, Dow Chemical Co., Dow EAA copolymer,
Mitsubishi Yuka Co., Ltd. Yucaron EAA, Mitsui DuPont Chemical Co., Ltd. Nucrel, Sumitomo Chemical Co., Ltd. Acryft, etc., and further, a copolymer of ethylene and acrylic acid or methacrylic acid, or a so-called ionomer obtained by crosslinking them. , Trade names such as DuPont's Surlyn, Mitsui Polychemical Co., Ltd., Himilan, Asahi Dow Co., Ltd. corborene latex, etc., BASF Corporation's EVA1 wax addition, and ethylene and vinyl acetate co-weight Partially saponified product of coalesce, trade name is Dumiran manufactured by Takeda Pharmaceutical Co., Ltd., copolymer of ethylene and acrylic ester, trade name is Nippon Unicar Co., Ltd. DPD-
6169 and the like, and further, a polyolefin resin containing a carboxylic carbonyl group and the like can be mentioned, and these resins can be used alone or in combination of two or more.

Next, the solvent for the olefin resin is
A solvent that dissolves a resin when heated and does not dissolve at room temperature, or a solvent that dissolves at room temperature and is insolubilized by cooling, may be any solvent that gives temperature dependence to solubility,
Solubility difference between 25 ℃ and 65 ℃ is 0.01g /
Any solvent may be used as long as it is at least ml, preferably 0.05 g / ml solvent. Examples of such a solvent include tetrahydrofuran, benzene, toluene, xylene, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetone, methyl ethyl ketone (ME).
K) and the like. The amount of the resin dissolved in the total of the solvent and the resin may be arbitrary, but if the resin ratio is too high,
Resin particles contact each other in the resin particle precipitation process,
Since it may become a gel-like mass, it is preferable to set it in the range of 1 to 80% by weight. The heating condition for dissolving the resin may be the lowest temperature required for dissolving the resin, and it is not preferable to heat more than necessary. It is preferable to stir according to a usual method during dissolution.

Next, as the colorant which can be used in the present invention, a known organic or inorganic colorant can be used.

The black colorant is an inorganic colorant.
Examples include bon black, ferrosoferric oxide, and organic cyanine black.

Examples of the yellow colorant include inorganic yellow lead, cadmium yellow, yellow iron oxide, titanium yellow and ocher. Further, as a acetoacetic acid anilide type monoazo pigment of a poorly soluble metal salt (azo lake), Hansa Yellow G (CINo. Pigment Yellow 1, hereinafter,
The same), Hansa Yellow 10G (pigment Yellow
3), Hansa Yellow RN (pigment Yellow 65),
Hansa Brilliant Yellow 5GX (pigment Yellow
74), Hansa Brilliant Yellow 10GX (pigme
nt Yellow 98), Permanent Yellow FGL (pig
ment Yellow 97), Shimura Lake Fast Yellow 6
G (pigment Yellow 133), Lionol Yellow K
-2R (pigment Yellow 169), and as acetoacetic acid anilide disazo pigment, disazo yellow G (p
igment Yellow 12), Disazo Yellow GR (pigme
nt Yellow 13), Disazo Yellow 5G (pigment Y
ellow 14), Disazo Yellow 8G (pigment Yello
w 17), Disazo Yellow R (pigment Yellow 5
5), Permanent Yellow HR (pigment Yellow 8
3) is mentioned. Examples of condensed azo pigments include Chromophtal Yellow 3G (pigment Yellow 93), Chromophtal Yellow 6G (pigment Yellow 94), and Chromophtal Yellow GR (pigment Yellow 95). Further, as a benzimidazolone-based monoazo pigment, Hosta Palm Yellow H3G (pigment Yellow 1
54), Hosta Palm Yellow H4G (pigment Yello
w 151), Hosta Palm Yellow H2G (pigment Y
ellow 120), Hosta Palm Yellow H6G (pigme
nt Yellow 175), Hosta Palm Yellow HLR (p
igment Yellow 156). Further, as an isoindolinone-based pigment, Irgadine Yellow 3RLT
N (pigment Yellow 110), Irgadine Yellow 2
RLT, Irgadine Yellow 2GLT (pigment Yello
w 109), Fastgen Super Yellow GROH
(Pigment Yellow 137), Fastgen Super Yellow GRO (pigment Yellow 110), Sandrin Yellow 6GL (pigment Yellow 173), and flavantron (pigment)
ment Yellow 24), anthramylimidine (pigment Y
ellow 108), phthaloylamide type anthraquinone (pigment Yellow 123), Heliofast Yellow E3R (pigment Yellow 99), metal complex pigment azo nickel complex pigment (pigment Green10), nitroso nickel complex pigment (pigment Yellow 153),
Azomethine-based copper complex pigment (pigment Yellow 117),
Further, phthalimide quinophthalone pigment (pigment Yellow 138), which is a quinophthalone pigment, may be mentioned.

Examples of magenta colorants include inorganic cadmium red, red iron oxide, silver vermilion, red lead and antimony vermilion. As an azo lake type azo pigment, Brilliant Carmine 6B (pigment Red 57:
1), lake red (pigment Red53: 1), permanent red F5R (pigment Red48), resole red (pigment Red49), persia orange (pigme
nt Orange17), Kurosei Orange (pigment Orange
18), Helio Orange TD (pigment Orange1
9), pigment scarlet (pigment Red60:
1), Brilliant Scarlet G (pigment 64:
1), Helio red RMT (pigment Red51), Bordeaux 10B (pigment Red63), Helio Bordeaux BL
(Pigment Red 54), and as the insoluble azo type (monoazo, disazo type, condensed azo type), Para Red (pigment Red1), Lake Red 4R (pigme
nt Red3), permanent orange (pigment Orange
5), Permanent Red FR2 (pigment Red2),
Permanent Red FRLL (pigment Red9), Permanent Red FGR (pigment Red112), Brilliant Carmine BS (pigment Red114), Permanent Carmine FB (pigment Red5), P.I. V. Carmine HR (pigment Red150), Permanent Carmine FBB (pigment Red146), Nova Palm Red F3
RK-F5RK (pigment Red170), Nova Palm Red HFG (pigment Orange38), Nova Palm Red HF4B (pigment Red187), Nova Palm Orange HL. HL-70 (pigment Orange36), P.
V. Carmine HF4C (pigment Red185), Hostabum Brown HFR (pigment Brown25), Vulcan Orange (pigment Orange16), Pyrazolone Orange (pigment Orange13), Pyrazolone Red (pi
gment Red38), and as a condensed azo pigment, Chromophtal Orange 4R (pigment Orange3)
1), Chromophtal Scarlet R (pigment Red1
66), chromophthal red BR (pigment Red14
4) is mentioned.

Further, pyranthrone orange (pigment Orange) is used as an anthraquinone pigment which is a condensed polycyclic pigment.
40), Antoanthrone Orange (pigment Orange
168), dianthraquinonyl red (pigment Red1
77), thioindigo magenta (pigment Violet38), thioindigo violet (pigment Violet36), thioindigo red (pigment Red88), and perinone orange (pigment Orange43). In addition, as perylene pigments, perylene red (pigment Red190), perylene vermillion (pig
ment Red123), Perylene Maroon (pigment Red1)
79), perilence scarlet (pigment Red14
9) and perylene red (pigment Red178). Quinacridone red (p
igment Violet19), quinacridone magenta (pigme
nt Red122), quinacridone maroon (pigment Red
206), quinacridone scarlet (pigment Red2
07), and other condensed polycyclic pigments include pyrocholine pigments, red fluorbin pigments, and dyed lake pigments (water-soluble dye + precipitant → lake fixing).

As the cyan colorant, an inorganic ultramarine blue,
Navy blue, cobalt blue, cerulean blue, etc. are mentioned, and as the phthalocyanine system, Fast Gemble-BB (pigment Blue 15), Sumiton cyanine.
Blue HB (pigment Blue 15), cyanine blue 5
020 (pigment Blue 15: 1), Sumika print
Cyanine Blue GN-O (Pigment Blue 15), Fast Sky Blue A-612 (Pigment Blue 1
7), cyanine green GB (pigment Green7),
Cyanine Green S537-2Y (pigment green3
6), Sumiton Fast Violet RL (pigment
Violet 23), and indanthrone blue (PB-60P, PB-22, P) which is a slene-based pigment.
B-21, PB-64), a basic dye lake pigment, methyl violet / phosphorus / molybdic acid lake (PV
-3) and the like.

In addition, a colorant called a so-called processed pigment in which the surface of the colorant is coated with a resin can be similarly used.

Considering the storage stability as a wet toner, or the transparency and color mixture of an image when a color image is formed using the obtained wet toner, among the above-mentioned colorants, a black type toner has a negative effect. It is preferable to use a mixture of benzidine yellow and Hansa yellow as the bonblack and yellow type, brilliant carmine 6B for the magenta type, and phthalocyanine blue for the cyan type.

The content of the colorant in the resin can be arbitrarily selected within the range of 0.0001 to 2000% by weight with respect to the weight of the resin, but in order to reproduce a multi-color continuous gradation equivalent to that of offset printing. Is required to have an optical reflection density of 0.7 or more after the transfer of each color toner to the transfer target,
Particularly, for cyan and black, 1.0 or more is desirable. In order to obtain an optical reflection density of 0.7 or more for each color, in the case of black and cyan, it is 10 to 150% by weight based on the same weight as above, and in the case of magenta, 4
0 to 150% by weight, yellow 10 to 100% by weight
It is good to do. When any of the colors exceeds the above range, the optical reflection density and the background stain of the formed image are likely to occur after development.

The colorant has a particle size of 30 to 15 in the secondary aggregation state.
It is also possible to use powder of 0 μm and heat-melt the resin to mix the colorant so that the resin and the colorant have a predetermined mixing ratio, and then disperse / dissolve in the solvent. The resin and the colorant may be separately dissolved in a solvent or dispersed by ultrasonic dispersion and then mixed, or the powder colorant may be dispersed in the resin solution.

Next, the liquid aliphatic hydrocarbon, which is an electrically insulating liquid, has a volume resistance of 10 ¹⁰ Ω · cm or more, and is used for the purpose of enhancing the electrical insulating property in the wet toner. Further, it is required that the dissolving power for the wet toner component is relatively small, which prevents deterioration as a wet toner.

Examples of liquid aliphatic hydrocarbons include n
-Paraffinic hydrocarbons, iso-paraffinic hydrocarbons, or mixtures thereof, halogenated aliphatic hydrocarbons and the like. A branched chain aliphatic hydrocarbon is particularly preferable, and it is preferable to use, for example, Isopar G, Isopar H, Isopar K, Isopar L, Isopar M, Isopar V manufactured by Exxon. These have almost no solubility in an olefin resin having a carboxyl group or an ester group. For example, the solubility of the resin in Isopar H is 0.001 g / Less than solvent ml.

Next, the polyhydroxycarboxylic acid ester will be described.

The polyhydroxycarboxylic acid ester is soluble in the electrically insulating liquid, and when it is added to the granulation step, resin particles obtained have a uniform particle size distribution. In addition, it has been found that it also has a function as a dispersant because it has an affinity with the resin particles in the wet toner.

The hydroxycarboxylic acid ester as a raw material for polymerization is a derivative such as an ester of the formula HO-X-COOH, where X is a divalent saturated or unsaturated aliphatic hydrocarbon containing at least 12 carbon atoms. , Or a divalent aromatic hydrocarbon containing at least 6 carbon atoms and there are at least 4 carbon atoms between the hydroxy and carboxyl groups. Preferred examples of such hydroxycarboxylic acid derivatives include hydroxycarboxylic alkyl esters such as 12-hydroxystearic acid methyl ester and 12-hydroxystearic acid ethyl ester, 12-hydroxycarboxylic acid lithium and 12-hydroxycarboxylic acid aluminum. Examples thereof include metal salts of hydroxycarboxylic acids, hydroxycarboxylic acid amides, hydrogenated castor oil, and the like.

The polyhydroxycarboxylic acid ester is obtained by polymerizing a hydroxycarboxylic acid ester by partially saponifying it in the presence of a small amount of amines or a catalyst, and its polymerization form is obtained by intermolecular esterification. In addition, it contains various forms such as those obtained by esterification in the molecule. The polyhydroxycarboxylic acid ester in the present invention is preferably a hydroxycarboxylic acid ester 3- to 10-mer, and is a light gray brown wax-like substance. When the degree of polymerization of the polyhydroxycarboxylic acid ester is less than 3 or more than 10, the polyhydroxycarboxylic acid ester is not compatible with the electrically insulating liquid, and even if it is used in the granulation step, the particle size distribution of the obtained resin particles is not good. You can't get the one you want. The addition amount of the polyhydroxycarboxylic acid ester is not particularly limited, but per resin weight,
It is used in a proportion of 0.01% by weight to 200% by weight. The polyhydroxycarboxylic acid ester may be added in the granulation step, but may be added to the resin solution or the pigment dispersion liquid.

The granulation step of the present invention is carried out by introducing the resin solution into the electrically insulating liquid, and it is not necessary to stir at the time of introduction, but it is preferable to stir and / or disperse by ultrasonic irradiation or the like. It is desirable to improve the dispersion of the precipitated resin particles by means. Regarding the cooling rate, dry ice, liquid nitrogen, or the like may be used for rapid cooling, cooling may be performed on the electrically insulating liquid, or natural cooling may be performed. When the resin solution is poured into the electrically insulating liquid,
Simultaneously with the precipitation of the resin particles due to the temperature difference of the resin solution, the precipitation of the resin particles occurs due to the difference in solubility between the resin and the electrically insulating liquid which is a poor solvent.

In this granulation step, since the polyhydroxycarboxylic acid ester has compatibility with the electrically insulating liquid and has a strong affinity with the resin particles, the resin particles to be precipitated have a particle size of submicron unit. It is considered that the above-mentioned product can be obtained and the one having a narrow particle size distribution can be obtained. That is, the particle size of the obtained particles is in the range of 0.1 to 10 μm,
In addition, D ₅₀ showing an average particle diameter shows a single peak of 0.6 to 0.8 μm, and does not require ball milling operation of resin particles, classification, etc., which are required by the conventional method, but if necessary, It goes without saying that fine pulverization may be further performed with a pulverizer such as a ball mill, pin pill or jet mill.

Next, after depositing the resin particles, it is desirable to replace the solvent with an electrically insulating liquid. As a method for this, the precipitated resin particles may be separated and washed by a means such as standing or centrifugation to remove the solvent and increase the concentration of the electrically insulating liquid.

In the wet toner of the present invention, as a charge control agent, a metal salt of dialkylsulfosuccinate, manganese naphthenate, calcium naphthenate, zirconium naphthenate,
Cobalt naphthenate, iron naphthenate, lead naphthenate, nickel naphthenate, chromium naphthenate, zinc naphthenate, magnesium naphthenate, manganese octylate, calcium octylate, zirconium octylate, iron octylate, lead octylate, octylate Cobalt, chromium octylate, zinc octylate, magnesium octylate,
Metal soaps such as manganese dodecylate, calcium dodecylate, zirconium dodecylate, iron dodecylate, lead dodecylate, cobalt dodecylate, nickel dodecylate, chromium dodecylate, zinc dodecylate, and magnesium dodecylate, calcium dodecylbenzenesulfonate, Alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate and barium dodecylbenzenesulfonate,
Phospholipids such as lecithin and sehalin, organic amines such as n-decylamine and the like can be preferably added. In particular, transition metal salts of dialkyl sulfosuccinic acids (cobalt, manganese,
It is preferable to use zirconium, yttrium, nickel, etc.). The addition amount may be the minimum amount showing the charge control effect, but it is usually preferable to be 0.01 to 50% by weight in the electrically insulating liquid.

The resin particles in the liquid developer thus obtained are positively or negatively charged. For example, those which are positively charged are those which give a positive image on an electrophotographic photosensitive member used for negative charging, for example, a zinc oxide / resin photosensitive member.

The charge control agent is a resin solution, a colorant dispersion,
It may be added at any stage in the liquid mixture thereof, the granulation step, and the final wet toner, but it is preferably added to the resin solution. This has the advantage that the charge control agents that can be used are not limited by the electrically insulating liquid. That is, since the charge control agent dissolved in the solvent remarkably lowers the electric resistance of the electric insulating liquid, it is desirable that the amount present in the electric insulating liquid is as small as possible, while the charge control agent is surely applied to the toner particles. In order to be adsorbed, it is desirable that the concentration of the charge control agent in the electrically insulating liquid is high, and both conditions are contradictory. However, according to the production method of the present invention, after the charge control agent is added to the resin solution to sufficiently adsorb it to the toner particles, the unnecessary charge control agent not involved in the toner particle adsorption can be removed by solvent replacement. This is because the above conditions can be satisfied.

In the wet toner obtained in the present invention, other fixing agents such as various resins soluble in an electrically insulating liquid, for example, modified or unmodified alkyd resin, ordinary acrylic resin, synthetic rubber, polyalkylene are used. Oxides, polyvinyl acetals (including butyral), vinyl acetate resins and the like can be added.

Further, the wet toner obtained in the present invention includes
Many anionic, cationic, amphoteric or nonionic surfactants can be added as a dispersant, and in addition to these, aliphatic acid salts used as the charge control agent and synthetic resins used as the fixing agent. And the like can be used as a dispersant.

When the wet toner according to the present invention is used for electrophotography, it is of course possible to carry out an ordinary transfer method, that is, electric field transfer such as corona transfer, on an insulating transfer target such as paper. However, it can be efficiently transferred to the electrically conductive transfer object such as metal from the surface of the electrophotographic photoreceptor by the pressure transfer method. Further, by transferring the toner of the present invention onto a lithographic printing plate substrate, an image area having high printing durability can be formed on the lithographic printing plate. This is because it is considered that the presence of the carbonyl group in the carboxyl group or ester group contained in the resin particles in the toner improves the adhesiveness to paper, plastics, metal, etc., and is brought about by the presence of the resin particles. It is considered that the appropriate flexibility absorbs the impact during printing.

[0038]

When olefin resin particles having a carboxyl group or an ester group are used as the resin particles in the wet toner, the pressure transfer properties are excellent, the flexibility is obtained even at room temperature, and the surface of the photoreceptor is damaged during the pressure transfer. In addition, when the image area of the lithographic printing plate is used, the image area itself has an appropriate elasticity. In addition, when direct printing is performed, the unevenness due to the transition of the paper that is the printing medium is absorbed, so printing can be performed with a certain printing pressure and a very smooth printed material can be obtained. Since the adhesion to the plate substrate is good,
There are advantages such as being able to obtain sufficient printing durability.

According to the present invention, a hydroxycarboxylic acid ester is used as a monomer in a granulation step in which a resin solution using a solvent having solubility to a resin is put into an electrically insulating liquid and cooled to precipitate resin particles. By adjusting the presence of the 3- to 10-mer polyhydroxycarboxylic acid ester, the polyhydroxycarboxylic acid ester is compatible with the electrically insulating liquid and has an affinity with the resin particles, and thus granulation adjustment is performed. By showing the function, the detailed reason is unknown, but the particle size of the resin particles to be precipitated is in the submicron unit, and it is possible to obtain an extremely narrow particle size distribution, without the need for ball milling operation, etc. The wet toner can be easily manufactured.

Further, in the obtained wet toner, the polyhydroxycarboxylic acid ester has not only the function of adjusting the granulation but also the function of stably dispersing the resin particles in the electrically insulating liquid due to the affinity with the resin particles. In addition, since the resin particles are stably maintained in the dispersion state in the wet toner, it becomes a wet toner without deterioration, and it becomes possible to form a contact toner.

Examples of the present invention will be shown below.

[0042]

Example 1 Partially saponified ethylene-vinyl acetate copolymer (Takeda Pharmaceutical Co., Ltd.) was placed in a 200 ml round bottom flask.
(Manufactured by Dumilan 2270, saponification degree 70%) 2.5 g, cobalt diisooctylsulfosuccinate 260 mg, and tetrahydrofuran 50 ml were mixed, and the mixture was heated and stirred at 50 to 60 ° C. for 1 hour to dissolve the resin to prepare a resin solution.

On the other hand, another container, Monastral blue FBR
(ICI, metal phthalocyanine pigment) 2.5 g, dispersant (ICI, Solsperse 17000) 40 mg, dispersant (Solsperse 5000) 40 mg, tetrahydrofuran 50 ml, ultrasonic homogenizer (Nippon Seiki Seisakusho Co., Ltd.) , US-300T) and mixed and dispersed for 10 minutes to prepare a pigment dispersion.

This pigment dispersion, the previously prepared resin solution, and poly-12-hydroxystearic acid methyl ester [manufactured by Ito Oil Co., Ltd., trimer, acid value 40.8 to 42.
8, saponification number 196.9 to 197.7, weight average molecular weight 1
200, a hue (Gardner-Herrige) 6 to 7, and 20 mg of light gray brown wax] were mixed and dispersed at 60 to 80 ° C. using an ultrasonic homogenizer to prepare a coating liquid.

This coating liquid was put into 150 ml of Isopar G (manufactured by Exxon Co.) cooled to 5 to 10 ° C. and mixed using an ultrasonic homogenizer for 0.5 to 1 hour to precipitate resin particles. ..

Particle size analysis of the resin particles by Microtrac-IISRA type (manufactured by Nikkiso Co., Ltd.) reveals that the resin particles have a particle size width of 0.3 to 1.25 μm and an average particle size D ₅₀ of 0.60 μm. Had a sharp and single peak distribution spectrum.

Next, a centrifuge (Sakuma Works Co., Ltd.)
(Manufactured by Autobalance System Model 90-4 large-capacity multiple centrifugal centrifuge) was used to separate the resin particles, and the resin particles were washed with Isopar G and further dispersed in Isopar G.

Particle size analysis of the resin particles after solvent substitution was carried out in the same manner. As a result, the resin particles were 0.42 to 0.96 μm.
It had a sharp and single peak distribution spectrum with a particle size width of m and an average particle size D ₅₀ of 0.60 μm.

Further, it was confirmed by infrared absorption spectrum that the polyhydroxycarboxylic acid ester was attached to the resin particles, that is, the OH group stretching vibration region at 3800 to 3200 cm ^-1 was quantified and the carbonyl group in the carboxylic acid ester was 1760. ~ 17
It was confirmed by the change in the peak position at 70 cm ^-1 .

This wet toner was diluted with Isopar G,
The print density was adjusted to 1% and used in the following developing process.

The developing process is carried out by using electrostatic recording paper (DScan Seiko Denshi KK, electrostatic plotter, EP-4010).
Various electrostatic patterns having a surface charge of 150 V to 50 V were formed on the (for use), and the wet toner prepared above was used to develop and print with a roller developing machine. The developing machine speed was 2.6 m / min and 10.0 m / min. For the photometric and colorimetric evaluation of the printed matter, Macbeth RD914 (manufactured by Macbeth Co., Ltd.) was used to measure the optical reflection density (OD value).

Further, in order to evaluate the electrophoretic property as a toner characteristic, a micro ammeter (Advantech Co., Ltd.) is used.
Made) and HIGH VOLTAGE SOUCE MEASURE UNIT (KEITHLEY
237) manufactured by the same company was used to measure the initial current value and the current value after 60 seconds, and at the same time, measure the current value per toner weight attached to the electrode (Q / m, unit μC / g). The larger the difference between the initial current value and the current value after 60 seconds and the larger the Q / m value, the better the electrophoretic property of the toner.

Further, the printability was visually evaluated with respect to its image quality (whether or not there is a feeling of roughness), flow (whether or not there is a blur), and degree of fogging.

The results of each evaluation are shown in Table 1 below.

[0055]

Example 2 Instead of the poly-12-hydroxystearic acid ester (trimer) in Example 1, poly-12 was used.
-Hydroxystearic acid methyl ester [manufactured by Ito Oil Co., Ltd., tetramer, acid value 35.9 to 37.0, weight average molecular weight 1560, hue (Gardner-Heliger) 6 to
7, light grey-brown wax] was similarly used to prepare a wet toner in the same manner as in Example 1.

Particle size analysis was conducted on the resin particles before solvent substitution in the same manner as in Example 1. As a result, a sharp single peak having a particle size width of 0.3 to 1.5 μm and an average particle size D ₅₀ of 0.89 μm was obtained. It had a distribution spectrum.

Further, evaluation as a wet toner was carried out in the same manner as in Example 1, and the results are also shown in Table 1.

[0058]

Example 3 Instead of the poly-12-hydroxystearic acid ester (trimer) in Example 1, poly-12 was used.
-Hydroxystearic acid methyl ester [manufactured by Ito Oil Co., Ltd., hexamer, acid value 23.2 to 25.7, weight average molecular weight 1890, hue (Gardner Helige) 5
6. Wet toner was prepared in the same manner as in Example 1 except that [6, light gray brown wax] was used.

Particle size analysis was performed on the resin particles before solvent substitution in the same manner as in Example 1. As a result, a sharp single peak having a particle size width of 0.17 to 2.6 μm and an average particle size D ₅₀ of 0.92 μm was obtained. It had a distribution spectrum.

Further, evaluation as a wet toner was carried out in the same manner as in Example 1, and the results are also shown in Table 1.

[0061]

Example 4 Partially saponified ethylene-vinyl acetate copolymer (Takeda Pharmaceutical Co., Ltd.) was placed in a 200 ml round bottom flask.
Manufactured by Dumilan 2270, saponification degree 70%) 2.5 g, cobalt diisooctylsulfosuccinate 256 mg, and tetrahydrofuran 50 ml were mixed, and the mixture was heated and stirred at 60 to 80 ° C. for 1 hour to dissolve the resin to prepare a resin solution.

On the other hand, in another container, Monastral blue RFN
(ICI, metal phthalocyanine pigment) 2.5 g and poly-12-hydroxystearic acid methyl ester (3
90 mg of tetrahydrofuran in 50 ml of tetrahydrofuran, ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho Co., Ltd., US-300)
T) was used and dispersed to prepare a pigment dispersion.

This pigment dispersion was poured into the previously prepared resin solution at once, and further mixed and dispersed for 1 hour at 60 to 80 ° C. using an ultrasonic homogenizer (the same as above) to prepare a coating liquid.

This coating solution was put into 150 ml of Isopar G (manufactured by Exxon Co.) cooled to 5 to 10 ° C. and mixed for 0.5 to 1 hour using an ultrasonic homogenizer (same as above) to obtain resin particles. It was deposited.

The particle size of the resin particles was analyzed by using Microtrac-IISRA type (manufactured by Nikkiso Co., Ltd.). The resin particles had a particle size width of 0.17 to 3.0 μm and an average particle size D ₅₀ of 0. It had a sharp, single peak distribution spectrum of 0.7 μm.

Next, a centrifuge (Sakuma Seisakusho Co., Ltd.)
(Manufactured by Autobalance Model 90-4 high-capacity multiple centrifugal centrifuge) was used to separate the resin particles, and the resin particles were washed with Isopar G and then dispersed in Isopar G.

When the particle size of the resin particles after solvent substitution was analyzed in the same manner, the resin particles were 0.42 to 1.2 μm.
It had a sharp and single-peak distribution spectrum with a particle size width of m and an average particle size D ₅₀ of 0.8 μm.

This wet toner was diluted with Isopar G,
The print density was adjusted to 1%, and the wet toner was evaluated in the same manner as in Example 1. The results are also shown in Table 1.

[0069]

[Example 5] Instead of the resin of Example 4, a partially saponified ethylene-vinyl acetate copolymer (Takeda Pharmaceutical Co., Ltd.)
A wet toner was prepared in the same manner as in Example 4 except that Dumilan 2280 and saponification degree 80%) were used.

The resin particles before solvent substitution were subjected to particle size analysis in the same manner as in Example 4 to find that they were 0.17 to 0.83 μm.
Had a sharp and single-peak distribution spectrum with a particle size width of 0.45 μm and an average particle size D ₅₀ of 0.45 μm.

Further, evaluation as a wet toner was conducted in the same manner as in Example 1, and the results are also shown in Table 1.

[0072]

Example 6 Instead of the resin of Example 4, an ethylene-vinyl acetate copolymer (Mitsui DuPont Chemical Co., Ltd., Evaflex 250, vinyl acetate component 28% by weight, MI value = 150) was used. A wet toner was produced in the same manner as in Example 4 except that magnesium naphthenate was used instead of diisooctylcobalt sulfosuccinic acid.

Particle size analysis of the resin particles before solvent substitution was carried out in the same manner as in Example 4 to find that it was 0.17 to 0.42 μm.
Had a sharp and single-peaked distribution spectrum with a particle size width and an average particle size D ₅₀ of 0.24 μm.

Further, evaluation as a wet toner was conducted in the same manner as in Example 1, and the results are also shown in Table 1.

[0075]

Example 7 An ethylene-vinyl acetate copolymer (Mitsui DuPont Chemical Co., Ltd., Evaflex 450, vinyl acetate component 19% by weight, MI value = 150) was used in place of the resin of Example 4. A wet toner was prepared in the same manner as in Example 6.

The particle size analysis of the resin particles before solvent substitution was carried out in the same manner as in Example 4 to find that it was 0.12 to 0.42 μm.
Had a sharp and single-peaked distribution spectrum with a particle size width and an average particle size D ₅₀ of 0.24 μm.

Further, the wet toner was evaluated in the same manner as in Example 1, and the results are also shown in Table 1.

[0078]

Comparative Example 1 Instead of the poly-12-hydroxystearic acid methyl ester (trimer) in Example 4, 12
A wet toner was prepared in the same manner as in Example 4 except that hydroxystearic acid (produced by Kanto Chemical Co., Inc.) was used.

When the particle size analysis was performed on the resin particles before solvent substitution in the same manner as in Example 4, the particle size width was 1.5 to 25 μm, and the average particle size D ₅₀ was as wide as 12.6 μm. Further, the initial current value of 110 nA (current value of 90 nA after 60 seconds) and the electrophoretic force are small, and the solid image formed on the electrostatic recording paper after corona charging is severely crisp.
There was a problem that a clean solid image could not be obtained, and the flow on the electrode plate and fixing were poor.

Further, the wet toner was evaluated in the same manner as in Example 1, and the results are also shown in Table 1.

[0081]

Comparative Example 2 Instead of poly-12-hydroxystearic acid methyl ester (trimer) in Example 4, poly-12-hydroxystearic acid methyl ester [manufactured by Ito Oil Co., Ltd., 10-mer or more, weight] Average molecular weight 420
0, molecular weight distribution width (= number average molecular weight / weight average molecular weight)
1.63, hue (Gardner-Heliger) 5-6, light gray-brown solid] was used to prepare a wet toner in the same manner as in Example 4.

Particle size analysis of the resin particles before solvent substitution was carried out in the same manner as in Example 4. As a result, a particle size width of 1.5 to 35 μm and an average particle size D ₅₀ of 15 μm were wide, and the initial current value was 140nA (current value 115n after 60 seconds)
A) and the electrophoretic force are small, and the solid image formed on the electrostatic recording paper after corona charging is severely crisp, a clean solid image cannot be obtained, and the flow and fixing on the electrode plate are poor. I had one.

Further, evaluation as a wet toner was conducted in the same manner as in Example 1, and the results are also shown in Table 1.

[0084]

[Table 1]

Claims (2)

[Claims] 1. A wet toner comprising olefin resin particles having a carboxyl group or an ester group alone, or olefin resin particles having a carboxyl group or an ester group added with a colorant, and most of liquid aliphatic hydrocarbons. A wet toner comprising a polyhydroxycarboxylic acid ester of a 3- to 10-mer containing a hydroxycarboxylic acid ester as a monomer. 2. An olefinic resin having a carboxyl group or an ester group alone or an olefinic resin having a carboxyl group or an ester group added with a colorant is dissolved by heating in a solvent having a high temperature dependence in solubility with respect to the resin. To obtain a resin solution, and then the resin solution is charged into a liquid aliphatic hydrocarbon in the presence of a polyhydroxycarboxylic acid ester of 3 to 10 mer containing a hydroxycarboxylic acid monomer as a monomer, and the resin particles are cooled. And a solvent is replaced with the aliphatic hydrocarbon, and a method for producing a wet toner, comprising: