JPH05297644A - Wet toner and its production - Google Patents

Abstract

PURPOSE:To obtain a wet toner whose resin particles have submicron-order particle size, having extremely narrow distribution of the particle size and good dispersibility, and without deterioration by incoporating an ester of polyhydroxycarboxylic acid into the toner. CONSTITUTION:This wet toner consists of olefin resin particles having carboxyl groups or ester groups with addition of a coloring agent and a large proportion of liquid aliphatic hydrocarbons. The toner contains a negative charge controlling agent and an ester of polyhydroxycarboxylic acid consisting of trimers to decamers of hydroxycarboxylic acid ester monomers. The negative charge controlling agent is soluble in the liquid aliphatic hydrocarbon. By using the negative charge controlling agent soluble in the liquid aliphatic hydrocarbon, it has high adsorptivity to the resin particles and has solubility in an electric insulating liquid so that the amt. of the charge controlling agent can be minimized to obtain high optical reflection density.

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 dispersing an olefin resin particle having a carboxyl group or an ester group in an electrically insulating liquid and at the same time adding a polyhydroxycarboxylic ester to the electrically insulating liquid. TECHNICAL FIELD The present invention relates to a wet toner which is dissolved in the toner and is suitable for electrophotography, 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 an advantage in that it has excellent resolution because the particle size of the colorant particles is small, but since the toner is fixed by drying and fixing the resin dissolved in the solvent, it can be formed with the printing plate substrate. Since the adhesiveness is poor and the cohesive force of the image area itself is small, the image area of the printing plate is easily removed during printing, and the printing durability is weak.

In a wet toner in which resin particles are dispersed, hydroxycarboxylic acid is dispersed in the resin particles to improve the physical properties of the toner. JP-A-63-243
No. 966 is known, but it cannot be said to be sufficient with respect to the toner physical properties such as image density, image quality, flow, and fog.

[0006]

According to the present invention, the resin particles can be processed in a submicron unit and the particle size distribution can be narrowed by simply dispersing the resin particles without using a grinding medium. It is an object of the present invention to provide a wet toner having further improved physical properties of toner such as fog and excellent negative chargeability and a simple method for producing the wet toner.

[0007]

The wet toner of the present invention comprises:
In a wet toner composed of olefin resin (hereinafter also referred to as olefin resin) particles having a carboxyl group or an ester group to which a colorant is added and most of liquid aliphatic hydrocarbons, a hydroxycarboxylic acid ester is used as a monomer 3 The present invention is characterized by the presence of a negative charge control agent compatible with a decameric polyhydroxycarboxylic acid ester and a liquid aliphatic hydrocarbon.

In the method for producing a wet toner of the present invention, an olefin resin is mixed with a liquid aliphatic hydrocarbon under heating and, at the same time, a colorant is mixed with the liquid aliphatic hydrocarbon. The colorant dispersion is added to the resin dispersion, mixed under heating, and then cooled, and then subjected to a mixing and dispersing step to produce a wet toner, in which hydroxycarboxylic acid ester is used as a monomer. The present invention is characterized in that a negative charge control agent compatible with the 3- to 10-mer polyhydroxycarboxylic acid ester and the liquid aliphatic hydrocarbon is present.

The present invention will be described in detail below.

A 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 a wet toner. It is required that the dissolving power with respect to the wet toner component is relatively small, which prevents deterioration as a wet toner.

Liquid aliphatic hydrocarbons include liquid 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. Further, the ratio of the olefinic resin to the liquid aliphatic hydrocarbon is preferably in a range such that it becomes fluid when the olefinic resin is mixed and dispersed in the liquid aliphatic hydrocarbon under heating conditions.

The liquid aliphatic hydrocarbon may be present in an amount of 0.01 to 80% by weight, preferably 0.1 to 50% by weight, based on the total weight of the solid content of the wet toner. It is preferable to store it in a state of being concentrated at a solid content concentration because it does not change with time. The wet toner at the time of development may be diluted with a liquid aliphatic hydrocarbon so as to have a solid content concentration of 0.5 to 2% by weight, and a preferable printed matter can be obtained.

Next, the olefin resin is preferably an ethylene-vinyl acetate copolymer. As the ethylene-vinyl acetate copolymer, Toray Soda Kogyo Co., Ltd. Ultrasen series, for example, 510X, 515F,
530,537,537L, 537S, 525,520F, 540,540F, 541,541L, 625,
630,630F, 682,627,631,633,680,681,635,634,710,720,7
Sumitomo Chemical Co., Ltd.'s Summit series, such as 22,725,751,750,760, for example, 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 a copolymer of ethylene and acrylic acid or methacrylic acid, or a so-called ionomer obtained by crosslinking them. The trade names are DuPont USA Surlyn, Mitsui Polychemicals Co., Ltd. Himiran, Asahi Dow Co., Ltd. corborene latex, etc., BASF Co., Ltd. EVA1 wax addition, and ethylene and acrylic ester Polymer, trade name of DPD-6 manufactured by Nippon Unicar Co., Ltd.
169 and the like, and further, a polyolefin-based resin containing a carboxyl carbonyl group and the like, and these resins can be used alone or in combination of two or more.

Next, the polyhydroxycarboxylic acid ester existing in the liquid aliphatic hydrocarbon dissolved therein will be described. The polyhydroxycarboxylic acid ester has a granulation adjusting function when it is present in the resin particle forming step, and the obtained resin particles having a uniform particle size distribution can be obtained. Further, it has affinity with the resin particles due to its structure, and also functions as a dispersant.

The hydroxycarboxylic acid ester which is a raw material for polymerizing the polyhydroxycarboxylic acid ester will be described. The hydroxycarboxylic acid ester is a compound in which the carboxylic acid in the hydroxycarboxylic acid represented by the following formula is alkylated or aralkyl esterified, amidated, or a metal salt. Formula HO
-X-COOH (wherein 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 hydroxy) There are at least 4 carbon atoms between the group and the carboxyl group.) Examples of such hydroxycarboxylic acid include ricinoleic acid, 10-
Hydroxystearic acid, 12-hydroxystearic acid, hydrogenated castor oil fatty acid (containing a small amount of stearic acid and palmitic acid in 12-hydroxystearic acid), 16-hydroxyhexadecanoic acid, 15-hydroxypentadecanoic acid, 12-hydroxy Dodecanoic acid, 4
-Hydroxybenzoic acid, 2-hydroxy-1-naphthoic acid, 3-hydroxy-2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxyphenylacetic acid, 3-
Hydroxyphenylacetic acid, 4-hydroxyphenylacetic acid, and 3- (4-hydroxyphenyl) -propionic acid. Next, as the derivative of hydroxycarboxylic acid, preferably, hydroxycarboxylic alkyl ester such as 12-hydroxystearic acid methyl ester and 12-hydroxystearic acid ethyl ester, 12-hydroxycarboxylic acid lithium, 12-hydroxycarboxylic acid aluminum and the like are used. A metal salt of hydroxycarboxylic acid,
Further, hydroxycarboxylic acid amide, hydrogenated castor oil and the like can be mentioned.

The polyhydroxycarboxylic acid ester is obtained by partially saponifying the above-mentioned hydroxycarboxylic acid ester in the presence of a small amount of amines or a catalyst, and its polymerization form is intermolecular. The polyhydroxycarboxylic acid ester of the present invention preferably has a degree of polymerization of 3 to 10 mer, and has a light gray brown color. Waxy substances are preferred. Its degree of polymerization is less than 3, or 1
If it is greater than 0, it is not compatible with liquid aliphatic hydrocarbons,
Even when used in the granulation step, the particle size distribution of the obtained resin particles is wide and the desired one cannot be obtained.

The amount of polyhydroxycarboxylic acid ester added is not particularly limited, but is 0.01 per weight of resin.
It is used in a proportion of from 200% by weight to 200% by weight. The polyhydroxycarboxylic acid ester may be added to the pigment dispersion liquid, but may be added to the resin dispersion liquid, or at the stage of mixing the pigment dispersion liquid and the resin dispersion liquid, or in the dispersion process after cooling. You may.

Next, a negative charge control agent compatible with the liquid aliphatic hydrocarbon is added to the wet toner of the present invention. “Compatible with an electrically insulating liquid” means that the solubility at 25 ° C. is 0.005 g / ml solvent or more, preferably 0.01 g / ml solvent or more. Examples of such a negative charge control agent include dialkyl sulfosuccinic acid metal salts, metal-containing azo colorants, lecithin and the like. In particular, the metal salt of dialkylsulfosuccinic acid is a metal salt of dialkylsulfosuccinic acid having an alkyl group having 5 to 17 carbon atoms, and the metal is atomic number 21 in the periodic table.
Of scandium to zinc of 30, yttrium 39 to cadmium of 48, lanthanum of 57 to mercury of 80, and actinium of 89 or higher, preferably cobalt, manganese, zirconium, yttrium. Metal salts such as nickel and nickel are preferable.
This type of negative charge control agent has a high adsorption ability for pigments and resin particles, and is compatible with an electrically insulating liquid, so that it can achieve its purpose with a minimum amount of use.

The addition amount of the negative charge control agent may be the minimum amount showing the charge control effect, but it is usually 0.01 to 50% by weight in the liquid aliphatic hydrocarbon, and is added. The timing may be added to the resin dispersion liquid, but may be added to the colorant dispersion liquid or a mixed liquid thereof, or may be added to the mixed liquid after cooling and mixed and dispersed. Good.

Next, as the colorant that 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 also
Examples of the insoluble azo type (monoazo, disazo type, condensed azo type) include Para Red (pigment Red1),
Rake Red 4R (Pigment Red3), Permanent Orange (Pigment Orange5), Permanent Red F
R2 (pigment Red2), Permanent Red FRLL
(Pigment Red9), Permanent Red FGR (pig
ment Red112), Brilliant Carmine BS (pigme
nt Red114), permanent carmine FB (pigment
Red5), P. V. Carmine HR (pigment Red15
0), permanent carmine FBB (pigment Red14
6), Nova Palm Red F3RK-F5RK (pigment
Red170), Nova Palm Red HFG (pigment Ora
nge38), Nova Palm Red HF4B (pigment Red1)
87), Nova Palm Orange HL. HL-70 (pigme
nt Orange36), P.n. V. Carmine HF4C (pigmen
t Red185), Hosta Verm Brown HFR (pigmen
t Brown25), Balkan Orange (pigment Orange1)
6), pyrazolone orange (pigment Orange13),
Pyrazolone Red (pigment Red38), and as a condensed azo pigment, Chromophtal orange 4R
(Pigment Orange31), chromophthal scarlet R (pigment Red166), chromophthal red B
R (pigment Red 144) may be mentioned.

Further, pyranthrone orange (pigment Orange) is used as an anthraquinone pigment which is a condensed polycyclic pigment.
40), Anto Antron 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, which is 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 by using the obtained wet toner, among the above 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 amount of the colorant used is 0.
Although it can be arbitrarily selected in the range of 0001 to 2000% by weight, in order to reproduce a continuous multi-tone gradation similar to that of offset printing, the optical reflection density after transfer of each color toner to the transfer target is 0.7. It is necessary to be above, and it is particularly desirable to be 1.0 or above for cyan and black.
In order to make the optical reflection density of 0.7 or more for each color, in the case of black and cyan, it is 10 based on the same weight basis as above.
˜150% by weight, preferably 40 to 150% by weight for magenta and 10 to 100% by weight for yellow. When any of the colors exceeds the above range, scumming is likely to occur after development.

The colorant has a particle size of 30 to 15 in the secondary aggregation state.
It is advisable to use a powder of 0 μm and disperse it in the liquid aliphatic hydrocarbon by ultrasonic dispersion or the like so as to obtain a predetermined mixing ratio with the resin.

The wet toner of the present invention also includes
As the fixing agent, for example, various resins soluble in an electrically insulating liquid, for example, modified or unmodified alkyd resin, ordinary acrylic resin, synthetic rubber, polyalkylene oxide, polyvinyl acetal (including butyral), vinyl acetate resin, etc. Can be added. Further, many anionic, cationic, amphoteric or nonionic surfactants can be added as a dispersant, and the synthetic resin or the like used as the above-mentioned fixing agent can also be used as a dispersant.

Next, a method of manufacturing the wet toner will be described. In the wet toner, the resin particles are made into particles by introducing the colorant dispersion liquid into the resin dispersion liquid, mixing the mixture, cooling the dispersion liquid, and then performing the dispersion treatment. When the olefin resin is mixed in the liquid aliphatic hydrocarbon under heating, and when the colorant dispersion is added to the resin dispersion and mixed under heating, the resin is plastic. It is sufficient that the temperature is a temperature sufficient for liquefying and liquefying and that each component does not decompose, and a general temperature range is 40 to 120 ° C.

As a cooling method, dry ice, liquid nitrogen or the like is used for rapid cooling, or it is poured into a cooled liquid aliphatic hydrocarbon and cooled to 5 to 15 ° C. to precipitate resin particles from the dispersion liquid. Let According to the findings of the present inventors, it was found that the average particle size of the resin particles is influenced by the cooling rate, and that the slow cooling rate increases the average particle size and the high cooling rate decreases the average particle size. .. The temperature at which the granulation occurs is 24 ° C. to about 30 ° C., and the average particle size can be reduced by allowing the granules to pass through as fast as possible, that is, by increasing the temperature gradient.

The mixing and dispersion treatment step performed after cooling is
Ultrasonic irradiation, high-speed disperser, jet mill, nibler, ong mill, ball mill, atomizer, etc. can be used to make the resin particles finer. That is, the particle size of the obtained particles is 0.1
Within the range of 10 μm, D ₅₀ showing the average particle size is 0.6 to
Those showing a single peak at 0.8 μm are obtained. Also,
By milling only the colorant in a separate step, a wet toner having a sharper particle size can be obtained.

The resin particles obtained by the present invention have a narrow particle size distribution range and exhibit a single peak.
Although the detailed reason for this is unknown, it is considered to be due to the granulation adjusting function and the dispersing function of the polyhydroxycarboxylic acid ester in the granulation step of the resin particles.

Next, when the wet toner according to the present invention is used for electrophotography, it is needless to say that a normal transfer method, that is, electric field transfer such as corona transfer is performed on an insulating transfer target such as paper. Although possible, it can be efficiently transferred from the surface of the electrophotographic photoreceptor to the electrically conductive transfer object such as metal by the pressure transfer method.

Further, by transferring the toner of the present invention to the substrate for a lithographic printing plate, it is possible to form an image area having a high printing durability 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 also brought about by the presence of the resin particles. It is considered that the appropriate flexibility absorbs the impact during printing.

[0036]

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 a lithographic printing plate is used, the image area itself has appropriate elasticity, and when direct printing is performed, the paper that is the printing medium As it absorbs the irregularities due to transitions, it can be printed with a constant printing pressure to obtain a very smooth printed matter. Also, because the adhesion of resin particles to the lithographic printing plate substrate is good, sufficient printing durability can be obtained. There is an advantage that power can be obtained.

Further, when a colorant dispersion liquid is added to the resin dispersion liquid to mix and disperse the mixture, the mixture is cooled and mixed and dispersed again to allow the polyhydroxycarboxylic acid ester to be present. Although the reason is unknown, the polyhydroxycarboxylic acid ester is compatible with the electrically insulating liquid and has an affinity with the resin particles, so that the wet toner can be easily formed by a dispersing means such as ultrasonic dispersion. It is possible to manufacture. Further, the polyhydroxycarboxylic acid ester also has a function of stably dispersing the resin particles in the electrically insulating liquid due to the affinity with the resin particles, and can be an excellent wet toner.

When a negative charge control agent compatible with a liquid aliphatic hydrocarbon is used as the charge control agent, it has a high adsorptivity for resin particles and exhibits an excellent negative chargeability.
In addition, the amount used can be minimized. Also,
High optical reflection density is obtained as compared with the case of using a negative charge control agent that is not compatible with the liquid aliphatic hydrocarbon.

Examples of the present invention will be shown below. The method for preparing the charge control agent used in the examples is as follows. Preparation of cobalt dialkyl sulfosuccinate. Sodium dialkyl sulfosuccinate (Wako Pure Chemical Industries, Ltd.)
Manufactured by Aerosol OT) 25 parts by weight of tetrahydrofuran 10
After mixing with 0 part by weight and heating and stirring at 50 ° C. to dissolve, 13 parts by weight of cobalt nitrate was added to 30 parts of tetrahydrofuran.
A solution dissolved in a mixed solvent consisting of parts by weight and 5 parts of methanol was added, and the mixture was heated with stirring at 50 ° C. for 30 minutes to precipitate a white salt. This white salt was filtered off, and the light purple filtrate was concentrated using an evaporator to obtain 10.9 parts by weight (yield 81%) of cobalt dialkylsulfosuccinate as a light red purple solid. The solubility in Isopar G (manufactured by Exxon) at 25 ° C. is 0.2 g / ml solvent.

Preparation of manganese dialkyl sulfosuccinate. In the method for preparing the cobalt dialkylsulfosuccinate, the same amount of manganese nitrate is used instead of cobalt nitrate,
The reaction was performed in the same manner except that tetrahydrofuran was dissolved in 30 parts by weight as the solvent to obtain manganese dialkylsulfosuccinate in a yield of 72%. Isopar G
Solubility at 25 ° C in (Exxon) is 0.15
g / ml solvent.

Method for preparing zirconium dialkyl sulfosuccinate. In the above-mentioned method for preparing cobalt dialkylsulfosuccinate, zirconium nitrate was used in the same amount in place of cobalt nitrate to cause a reaction, and zirconium dialkylsulfosuccinate was obtained in a yield of 70%. The solubility in Isopar G (manufactured by Exxon) at 25 ° C. is 0.13 g / ml solvent.

Method for preparing yttrium dialkyl sulfosuccinate. In the above method for preparing cobalt dialkylsulfosuccinate, the amount of sodium dialkylsulfosuccinate used is 7
The amount was 5 parts by weight, and yttrium nitrate was used in the same amount in place of cobalt nitrate to carry out the reaction to obtain yttrium dialkylsulfosuccinate in a yield of 45%. Solubility in Isopar G (manufactured by Exxon) at 25 ° C is 0.2 g / ml solvent
Is.

Method for preparing nickel dialkyl sulfosuccinate. In the above-mentioned method for preparing cobalt dialkylsulfosuccinate, nickel nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was used in the same amount in place of cobalt nitrate to react with nickel dialkylsulfosuccinate at a yield of 82%. Obtained. The partially precipitated green microcrystals were removed by hot filtration. The solubility in Isopar G (manufactured by Exxon) at 25 ° C. is 0.
1 g / ml solvent.

[0044]

Example 1 2.5 g of EVA (ethylene-vinyl acetate copolymer, Mitsui DuPont Chemical Co., Ltd., Evaflex 250, vinyl acetate component 28% by weight, MI value 150), tetra- in a 200 ml round bottom flask. Cobalt 2-ethylsulfosuccinate 256 mg, and Isopa-G 1
00 ml was mixed and heated and stirred at 150 ° C. for 1 hour in an oil bath.

On the other hand, Monast is used as a cyan pigment in another container.
ral blue FBR (Metal phthalocyanine pigment manufactured by ICI)
2.5 g 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 1200, hue (Gardner-Heliger) 6 to 7,
Light gray brown wax] 20 mg and Isopa-G100
dispersed in ml.

This pigment dispersion was added once to the resin dispersion prepared above, and the mixture was stirred and mixed at 150 ° C. for 1 hour. Next, this mixed solution is left at room temperature, cooled to about 70 ° C., and then put into 100 ml of Isopar G at 5 ° C., and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho Co., Ltd.,
US-300T) was used to disperse and mix to obtain a wet toner.

When the particle size of the resin particles was analyzed by Microtrac-Mark II SRA type (manufactured by North & Slop Co., Nikkiso Co., Ltd.), the resin particles were 0.17-1.
With a particle size width of 69 μm and an average particle size D ₅₀ of 0.72 μm,
It had a sharp and single peak distribution spectrum.

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 performed by using electrostatic recording paper (DScan Seiko Denshi KK).
(Manufactured by Electrostatic Plotter for EP-4010), various electrostatic patterns having a surface charge of 150 V to 50 V were formed, and the wet toner prepared above was used to develop and print with a roller developing machine. Processor speed is 2.6 m / min and 1
It was performed at 0.0 m / min. The developing characteristics showed bipolarity.

The photometric and colorimetric evaluation of the printed matter was carried out by "Spectrocolorimeter system CM-1000" manufactured by Minolta Co., Ltd. FIG. 1 is a diagram showing the light absorption curve. In addition, the optical reflection density (O
The D value) was measured using Macbeth RD914 (manufactured by Macbeth Co., Ltd.). Micro ammeter (Advantech Co., Ltd.) to evaluate the electrophoretic property of the toner
And HIGH VOLTAGE SOUCE MEASURE UNIT (KEITHLEY 237) are used to fill the wet toner between the metal electrode plates with a certain distance and area sandwiched between them, and the initial current value is measured and the current value is measured after 60 seconds. The current value (Q / m, unit: μC / g) per weight of the toner attached to was measured. 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, regarding the printability, the image quality (whether or not there is a feeling of roughness), the flow (whether or not there is bleeding), and the degree of fog were visually evaluated.

The results of each evaluation are shown in Table 1 below. In the evaluation items in the table, “◯” in “image quality” indicates that there is no roughness, “x” indicates that there is roughness, “◯” in “flow” indicates that there is no blur, and x indicates that there is blur.

[0052]

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.

When the particle size analysis of the resin particles was conducted in the same manner as in Example 1, it had a sharp single-peak distribution spectrum with a particle size width of 0.17 to 5.27 μm and an average particle size of 1.12 μm. .. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0054]

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 of the resin particles was carried out in the same manner as in Example 1. As a result, a sharp and single peak distribution spectrum having a particle size width of 0.17 to 6.53 μm and an average particle size of 1.25 μm was obtained. .. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0056]

[Example 4] In place of the cyan pigment of Example 1, the same amount of CI Pigment 57: 1 surface rosin ester partially treated product of magenta pigment Brilliant Carmine 6B # F (Dainichi Seika Co., Ltd.) was used. A wet toner was prepared in the same manner as in Example 1.

Particle size analysis of the resin particles was carried out in the same manner as in Example 1. As a result, a sharp and single peak distribution spectrum having a particle size width of 0.24 to 1.69 μm and an average particle size of 0.85 μm was obtained. ..

The photometric and colorimetric evaluation was performed in the same manner as in Example 1,
The light absorption curve is shown in FIG. The developing property was positive chargeability. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

Further, instead of the cyan pigment of Example 1, a yellow pigment 2400B (Dainichi Seika Co., Ltd.) CI Pigmen
A wet toner was prepared in the same manner as in Example 1 except that the same amount of t Yellow 17 was used. The particle size analysis of the resin particles was carried out in the same manner as in Example 1. As a result, the resin particles had a sharp single peak distribution spectrum with a particle size width of 0.83 to 11.15 μm and an average particle size of 0.98 μm. The developing property was positive chargeability. The photometric and colorimetric evaluation was performed in the same manner as in Example 1, and
The light absorption curve is shown in.

[0060]

Example 5 Instead of the resin of Example 1, EVA (ethylene-vinyl acetate copolymer, Mitsui DuPont Chemical Co., Ltd., Evaflex 460, vinyl acetate component 19% by weight, MI value 462.5) was used. A wet toner was prepared in the same manner as in Example 1 except that 2.5 g was used. The developing property was positive chargeability.

When the particle size analysis of the resin particles was conducted in the same manner as in Example 1, the particle size width of 0.34 to 21 μm and the average particle size of 4.
It had a sharp, single peak distribution spectrum of 30 μm. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0062]

Example 6 A wet toner was prepared in the same manner as in Example 1 except that 256 mg of nickel diisooctylsulfosuccinate was used instead of 256 mg of cobalt tetra-2-ethylsulfosuccinate of Example 1. The developing property was bipolar. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0063]

Example 7: Instead of 256 mg of cobalt tetra-2-ethylsulfosuccinate of Example 1, 256 mg of zirconium diisooctylsulfosuccinate was used,
A wet toner was prepared in the same manner as in Example 1. The developing property was bipolar. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0064]

Example 8 A wet toner was prepared in the same manner as in Example 1 except that 256 mg of manganese diisooctylsulfosuccinate was used instead of 256 mg of cobalt tetra-2-ethylsulfosuccinate of Example 1. The developing property was bipolar. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0065]

Example 9: Instead of 256 mg of cobalt tetra-2-ethylsulfosuccinate of Example 1, 256 mg of yttrium diisooctylsulfosuccinate was used, except that
A wet toner was prepared in the same manner as in Example 1. The developing property was bipolar. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0066]

Comparative Example 1 Instead of the poly-12-hydroxystearic acid methyl ester (trimer) in Example 1, 12
A wet toner was prepared in the same manner as in Example 1 except that hydroxystearic acid (produced by Kanto Chemical Co., Inc.) was used. The developing property was positive chargeability. When the particle size analysis of the resin particles is performed in the same manner as in Example 1, the particle size width is 0.17 to 60 μm, the average particle size is 7.53 μm, and the particle size width is wide, and the initial current value 238 nA (current value 134 n after 60 seconds is 134 n).
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. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0067]

Comparative Example 2 Instead of the poly-12-hydroxystearic acid methyl ester (trimer) in Example 1, 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 1.

When the particle size analysis of the resin particles is carried out in the same manner as in Example 1, the particle size width of 0.24 to 60 μm and the average particle size are 8.
It has a wide grain size of 7 μm and an initial current value of 150 n.
A (current value 95 nA after 60 seconds) and electrophoretic force are small,
Further, the solid image formed on the electrostatic recording paper after corona charging has a problem that the image is severely crisp, a clean solid image cannot be obtained, and the flow and fixing on the electrode plate are poor. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0069]

Comparative Example 3 A wet toner was prepared in the same manner as in Example 1 except that 300 mg of sodium diisooctylsulfosuccinate was used instead of 256 mg of cobalt diisooctylsulfosuccinate in Example 1. Incidentally, sodium diisooctyl sulfosuccinate (manufactured by Wako Pure Chemical Industries, Ltd.,
Product name Aerosol OT) Isopar G (manufactured by Exxon)
The solubility at 25 ° C. for is about 0.2 g / ml solvent. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0070]

Comparative Example 4 A wet toner was prepared in the same manner as in Example 1 except that 256 mg of calcium diisooctylsulfosuccinate was used instead of 256 mg of cobalt diisooctylsulfosuccinate in Example 1. Incidentally, calcium diisooctyl sulfosuccinate (manufactured by Wako Pure Chemical Industries, Ltd.)
Solubility in Isopar G (manufactured by Exxon) at 25 ° C. is 0.2 g / ml of solvent. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0071]

Comparative Example 5 A wet toner was prepared in the same manner as in Example 1 except that the poly-12-hydroxystearic acid methyl ester (trimer) in Example 1 was omitted.

When the particle size analysis of the resin particles was conducted in the same manner as in Example 1, the particle size width of 1.69 to 60 μm and the average particle size were 1
The particle size was as wide as 3.4 μm, and it was impossible to control the particle size in the submicron range. Also, the initial current value 18
The electrophoretic force was as small as 0 nA (current value 110 nA after 60 seconds), and the solid image formed on the electrostatic recording paper after corona charging was extremely dry and a clean solid image was not obtained.
The problem is that the flow on the electrode plate and the fixing are poor. Also, evaluation as a wet toner was performed in the same manner as in Example 1, and the results are also shown in Table 1.

[0073]

Comparative Example 6 A wet toner was prepared in the same manner as in Example 1 except that the negative charge control agent in Example 1 was omitted.

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]

[Table 1]

[Brief description of drawings]

FIG. 1 is a light absorption curve of a printed matter when printed using a wet toner containing a cyan pigment.

FIG. 2 Light absorption curve of printed matter when printed using a wet toner containing a magenta pigment

FIG. 3 is a light absorption curve of a printed matter when printed using a wet toner containing a yellow pigment.

Claims (2)

[Claims] 1. A wet toner comprising a colorant-added olefin-based resin particle having a carboxyl group or an ester group and most of a liquid aliphatic hydrocarbon, and a 3- to 10-mer having a hydroxycarboxylic acid ester as a monomer. A wet toner comprising a negative charge control agent compatible with the polyhydroxycarboxylic acid ester and the liquid aliphatic hydrocarbon. 2. An olefin resin having a carboxyl group or an ester group is mixed with a liquid aliphatic hydrocarbon under heating, and a coloring agent is mixed with the liquid aliphatic hydrocarbon separately from the olefin resin, and then the coloring is performed. The agent dispersion is added to the resin dispersion, mixed under heating, and then cooled, and then subjected to a mixing / dispersing step to produce a wet toner, and a hydroxycarboxylic acid ester is used as a monomer in the producing step. A method for producing a wet toner, characterized in that a negative charge control agent having compatibility with the 3- to 10-mer polyhydroxycarboxylic acid ester and the liquid aliphatic hydrocarbon is present.