JPH07219271A - Dispersing solution for producing toner, its production and production of electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To produce a small particle diameter-toner capable of keeping excellent picture image quality over an extremely long period in a high yield. CONSTITUTION:A dispersing solution for producing toner is for producing the toner particle by dispersing and granulating a solution, which is obtained by dissolving or dispersing a toner material containing a binder resin and a coloring agent in an organic solvent capable of dissolving the binder resin, in a water- based dispersing solution and contains calcium triphosphate obtained by allowing sodium triphosphate to react with calcium chloride in an alkaline water-alcohol medium as a dispersion stabilizing agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention produces a toner for developing an electrostatic charge image, which visualizes an electrostatic charge image formed on the surface of a photoreceptor in electrophotography, electrostatic recording, etc., by a so-called submerged granulation method. The present invention relates to a dispersion liquid for producing a toner, a method for producing the same, and a method for producing a toner for developing an electrostatic image.

[0002]

2. Description of the Related Art An electrophotographic system is disclosed in US Pat.
No. 7,691, British Patent Nos. 1,165,406 and 1,165,405, a photoconductive material is uniformly applied to a photoreceptor. A charging step for imparting an electrostatic charge, an exposure step for irradiating light to form an electrostatic latent image, a developing step for adhering toner to a latent image portion, a transfer step for transferring to a toner image support, a heat treatment for the toner image, It consists of a fixing process to fix it to the image support with pressure, flash light, etc., a cleaning process to remove the toner remaining on the photoconductor, and a static elimination process to remove the electrostatic charge on the photoconductor and return it to the initial state. Repeatedly produces several prints.

As an electrostatic charge image developing toner used in the field of electrophotography, a toner using a polyester resin obtained by subjecting a glycol having a bisphenol skeleton and a polybasic acid to a condensation reaction (Japanese Patent Publication No. 25-25420). Gazette), toner using polystyrene resin (Japanese Patent Publication No.
16118), a toner using a styrene / butyl methacrylate copolymer resin (Japanese Patent Publication No. 56-11143), and a toner using a bisphenol type epoxy resin obtained by reacting bisphenol with epichlorohydrin (JP-A-57- No. 96354) is known.

[0004]

By the way, in recent years, with the diversification of information, as for the method of expressing information, instead of the conventional image formation with monochrome toner, image formation with color toner is required. Came. Further, there is a demand for a toner having a high resolution, that is, a toner having a small particle size capable of fine expression in response to the movement of higher density of information. However, in response to these market trends,
The so-called pulverization method toner in which a resin, a colorant and other additives are melt-kneaded and then pulverized has various problems described below.

(1) In order to obtain a toner excellent in color tone reproducibility, a low molecular weight resin which is sharply melted at the time of fixing is required. However, since it has a low molecular weight, a colorant and other additives are dispersed during melt kneading. Is insufficient, the color tone of the fixed image is poor, and the composition of the toner is inhomogeneous, resulting in poor image quality. (2) Since it is a low molecular weight resin, the melt-kneaded product is easily over-milled and the yield is low. Further, finely pulverized particles scatter during printing to deteriorate image quality or pollute the environment.

A so-called submerged granulation method is known as another production method other than the pulverization method. For example, a method is known in which a toner material is dissolved in a solvent, the solution is granulated to a predetermined particle size in an aqueous medium containing an organic dispersant, for example, methyl cellulose, and then the solvent is removed (special feature). (Kaihei 1-257856). However, the toner obtained by this method also has the following many problems. An organic dispersant having a high affinity for water remains on the surface of the toner particles from which the solvent has been removed, resulting in poor charging properties and environmental stability, which are basic characteristics that the toner must have, and are far from practical use. Furthermore, since the residual organic dispersant covers the toner surface to form a thin layer, the toner meltability at the time of fixing is reduced and the original color tone is not expressed, or when used as a full-color toner, the transparency of the fixed toner is reduced. Inferior, the toning property due to mixing of the three primary colors may not remain. Further, since the toner particles are spherical in shape, the untransferred toner on the photoconductor after transferring the toner to the image support is poorly cleaned and cannot be repeatedly used.
The present invention solves the problems as described above. In the submerged granulation method, the color tone is excellent in reproducibility, the particle size can be reduced, the chargeability and the environment resistance are excellent, and the image quality is improved even after repeated use. Disclosed is a dispersion liquid for producing a toner, a method for producing the same, and a method for producing a toner for developing an electrostatic charge image using the same, which is capable of producing a toner in which the deterioration of the toner and the cleaning failure do not occur.

[0007]

According to the present invention, a liquid obtained by dissolving or dispersing a toner material containing a binder resin and a colorant in an organic solvent capable of dissolving the binder resin is dispersed in an aqueous dispersion liquid. A dispersion for producing toner particles by granulation, comprising tricalcium phosphate obtained by reacting trisodium phosphate and calcium chloride in an alkaline water-alcohol medium as a dispersion stabilizer. And a method for producing the same. Further, the present invention is
To the toner production dispersion liquid, a toner material containing a binder resin and a colorant is dissolved or dispersed in an organic solvent capable of dissolving the binder resin, and the mixture is dispersed and granulated to produce particles. Then, the present invention relates to a method for producing a toner for developing an electrostatic charge image, which comprises removing the solvent from the particles.

The toner-producing dispersion according to the present invention is a toner obtained by dispersing or granulating a liquid obtained by dissolving or dispersing a toner material containing a binder resin and a colorant in an organic solvent capable of dissolving the binder resin. Method for producing particles (so-called submerged granulation method)
Is used for. This dispersion contains tricalcium phosphate obtained by reacting trisodium phosphate and calcium chloride in an alkaline water-alcohol medium as a dispersion stabilizer.

An example of the reaction formula of this reaction is shown below.

[Chemical 1] As is clear from the above reaction formula, the reaction product crystals may contain calcium hydroxide together with tricalcium phosphate. The tricalcium phosphate referred to in the present invention also refers to such a compound having a crystal structure containing tricalcium phosphate as a main component, which is called hydroxyapatite.
The above reaction is preferably carried out by adjusting the alkali concentration so that the pH in the aqueous medium is always 7.5 or more. In particular, alkali is used in an amount of 0 to 0.2 molar equivalents in excess of the stoichiometric stoichiometric amount (2 molar equivalents) of the above reaction formula, and the total amount is added at the initial stage of the reaction. It is preferable to proceed the reaction and adjust the pH at the end of the reaction to 7.5 to 12. When the alkali is insufficient during the reaction, the crystal structure of the obtained tricalcium phosphate changes, and at the same time, the average particle size of the crystal particles increases,
The function as a dispersion stabilizer tends to be lowered, and the resulting toner particles tend to have a large particle size. on the other hand,
Similar results are obtained even if the amount of alkali is excessive. The alkali used in the above reaction is preferably an inorganic type. Preferred specific examples are sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium hydrogen carbonate, potassium carbonate, calcium hydroxide, magnesium hydroxide and the like, and particularly preferred specific example is sodium hydroxide.

As the calcium chloride, any of anhydrous salt, dihydrate, hexahydrate and the like may be used. In the reaction, trisodium phosphate is added in an amount of 0 to 1.5 molar excess over the theoretical molar equivalent of the reaction, that is, 6 to 10 molar amount of calcium chloride.
It is preferable to add 7.5 mol. Outside this range,
Since the crystal particle size of the obtained tricalcium phosphate is large, the function as a dispersion stabilizer tends to decrease.
A particularly preferred compounding amount is 6.3 to 7.2 mol, and in this case, a suspension stabilizer excellent in stability can be obtained especially in combination with refinement of the obtained tricalcium phosphate crystals.

In the present invention, the reaction between calcium chloride and trisodium phosphate is carried out in a water-alcohol medium (mixed medium of water and alcohol). Where alcohol is
When crystals of tricalcium phosphate, which is a reaction product, are precipitated, the dissolution of the crystals in water is suppressed, so that the crystals are generated earlier, and as a result, the particle size of the crystals can be reduced. By using this, it is possible to further reduce the toner particle size and improve various developing characteristics. As the alcohol in the water-alcohol medium, those soluble in water are preferably used. A suspension stabilizer mixed with an alcohol which is hardly soluble or insoluble in water tends to contaminate the toner mother liquor in the granulation process and significantly deteriorate the toner characteristics. Preferred water-soluble alcohols are alkyl alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, and isobutyl alcohol, glycols such as ethylene glycol and propylene glycol, and glycerin.
Of these, more preferred are alkyl alcohols, and particularly preferred are methyl alcohol and ethyl alcohol. These cause little contamination of the toner mother liquor. The amount of alcohol added was 0.
It is preferably from 2 to 10% by weight. A particularly preferred amount is 0.4 to 5% by weight. If it is less than 0.2% by weight, the effect of reducing the size of tricalcium phosphate crystals is small, while
If it exceeds 10% by weight, the toner mother liquor tends to be contaminated.

For the reaction between calcium chloride and trisodium phosphate, it is preferable to mix them as an aqueous solution or a water-alcohol solution. In particular, a water-alcohol solution in which trisodium phosphate and an alkali are dissolved is added to an aqueous solution of calcium chloride. Is preferably added dropwise and mixed, or an aqueous solution of trisodium phosphate is added dropwise to and mixed with a water-alcohol solution in which calcium chloride and an alkali are dissolved. The dropping time is within 45 minutes, preferably 5 to 30 minutes. If the dropping time exceeds 45 minutes, the crystal grain size becomes large,
The function as a dispersion stabilizer tends to decrease. The reaction temperature is preferably 0 to 55 ° C, particularly preferably 15 to 35 ° C. If the reaction temperature is lower than 0 ° C., special cooling equipment is required, while if it exceeds 55 ° C., the crystal particle size of the obtained tricalcium phosphate becomes large, so that the function as a dispersion stabilizer tends to decrease. The aqueous solution concentration of trisodium phosphate is preferably adjusted so as to be saturated at the reaction temperature.

The crystals of tricalcium phosphate produced as described above have an average particle size of 0.5 to 4 μm.
m, particularly preferably 1 to 3 μm. The reason for this is that there is very little adverse effect on the granulation property and its stability, and further on the properties of the obtained toner. The average particle size referred to here is the sub-micron particle analyzer Coulter (SUB-MICRON PARTICLE ANALYZER C
OURTER) model N4MD (manufactured by COURTER ELECTRONICS) and measured with ethanol in a dispersed state at a measurable concentration. The dispersion concentration is 1 to 200 μg / ml, and the dispersion in the ethanol solution is treated with ultrasonic waves for 3 to 5 minutes. The produced crystals of tricalcium phosphate are dispersed in an aqueous medium as a dispersion stabilizer to obtain a toner production dispersion liquid. The dispersion liquid after the reaction may be used as it is as a dispersion liquid for producing a toner.

Next, a method for producing a toner using this dispersion will be described in detail. To this dispersion, a toner material containing a binder resin and a colorant is dissolved or dispersed in an organic solvent capable of dissolving the binder resin, and the mixture is granulated by dispersion granulation. The binder resin for the toner is not particularly limited as long as it is used for ordinary toners, and examples thereof include styrene resin, acrylic resin, styrene-acrylic resin, polyester resin, silicone resin, epoxy resin, Xylene resin, diene resin, phenol resin, terpene resin, coumarin resin, amide resin, amide imide resin, butyral resin, urethane resin, ethylene / vinyl acetate resin and the like are used. Among these, styrene resins, acrylic resins, styrene-acrylic resins, polyester resins and the like are preferable because they have a good balance of toner characteristics. As for the molecular weight of the binder resin, the number average molecular weight (Mn) is preferably 1000 to 100,000, and the molecular weight dispersity (Mw / Mn) is preferably 3.5 to 100. The glass transition temperature is preferably 35 to 100 ° C, and particularly preferably adjusted to 50 to 80 ° C. When the glass transition temperature is lower than 35 ° C., the toner is apt to cause blocking (a phenomenon in which toner particles aggregate and agglomerate) during storage or in a developing machine. On the other hand, the glass transition temperature is 100
When the temperature exceeds ℃, a large amount of heat energy is required for fixing the toner. The binder resin is preferably added to the toner in an amount of 40 to 95% by weight. If this amount is less than 40% by weight, the binding force to the toner image support is weak and the toner image is likely to be lost when the toner image support is bent or rubbed, and information is likely to be lost. On the other hand, if it exceeds 95% by weight, the toner image hiding power tends to be insufficient, and poor print quality tends to occur.

The toner of the present invention contains a colorant and, if necessary, other additives. Carbon black, acetylene black, iron black, as colorant for black toner,
Aniline black, cyanine black, etc.
Carbon black is preferably used. Naphthol Yellow S as a yellow colorant for color toner
(C.I. 10316), Hansa Yellow 10G (C.I.
I. 11710), Hansa Yellow 5G (C.I. 116)
60), Hansa Yellow G (C.I. 11680), Hansa Yellow R (C.I. 12710), Pigment Yellow L (C.I. 12720), Benzidine Yellow G (C.I.
I. 21095), permanent yellow NCG (C.
I. 20040), Vulcan First Yellow 5G
(C.I. 21220), quinoline yellow (C.I. 4)
7005), Permanent Yellow FGL (C.I. 11)
767), permanent yellow HR (C.I. 2110)
8) and the like.

Permanent Red 4 as a red colorant
R (C.I. 12070), Para Red (C.I. 12)
120), Brilliant Fast Scarlet (C.
I. 12315), Brilliant Carmine BS (C.
I. 12351), Permanent Red F4R (C.
I. 12335), Vulcan Fast Rubin B (C.
I. 12320), Light Fast Red Toner B
(C.I. 12450), Lake Red C (C.I. 1
5585: 1), Brilliant Carmine 6B (C.I.
15850: 1), Rhodamine Rake B (C.I. 45)
170: 2) and the like.

Cobalt blue (C.I.
I. 77346), alkali blue lake (C.I. 4)
2750: 1), Victoria Blue Rake (C.I.4)
4045: 2), metal-free phthalocyanine blue (C.
I. 74100), phthalocyanine blue (C.I.
4160), Fast Sky Blue (C.I. 741)
80: 1) and the like. Further, as orange colorants, permanent orange (C.I. 12075), vulcan first orange GG (C.I. 2116)
5), Indanthrene Brilliant Orange RG (C.
I. 59300), fast violet B (CI. 12321) as a purple colorant, methyl violet lake (CI. 42535), pigment green B (CI. 10006) as a green colorant, acid green lake, Phthalocyanine green (C.I.
74260) and other organic pigments, inorganic pigments and dyes. The above colorants can be used alone or in combination. These colorants are 0.1 to 15% by weight in the toner.
It is preferably added.

As the toner material, various kinds of other additives can be mentioned. For example, in order to obtain a toner for developing an electrostatic image having magnetism, a magnetic or magnetizable toner material such as hematite or magnetite containing an oxide such as iron, cobalt or nickel may be added. further,
As an anti-offset agent, butyl stearate, lower alcohol esters of fatty acids such as propyl stearate,
Higher alcohol esters of fatty acids such as casta wax, diamond wax, palm acetyl, Hoechst wax E, Hoechst wax OP, higher alcohol esters such as carnauba wax, bisamide blast flow, amides 6L, 7S, 6H, alkylenes such as Hoechst wax C Bis fatty acid amide compound, ethylene, propylene, butene, hexene, heptene, octene, nonene, decene, 3-methyl-1-butene, 3-methyl-2
Examples thereof include polymers of olefin monomers such as pentene and 3-propyl-5-methyl-2-hexene, and copolymers of the above olefin monomers with acrylic acid, methacrylic acid, butyl acetate and the like. Of these, polypropylene is particularly preferable. These are 0.1-10 with respect to the toner.
It is preferable to add it in an amount of 0.1% by weight, particularly 0.1-5% by weight.
If the amount is less than 0.1% by weight, a sufficient offset preventing effect is difficult to be exhibited, and if the amount exceeds 10% by weight, the powder fluidity of the toner is lowered and the developability is deteriorated, or the transparency of the toner is lowered. It becomes difficult to obtain the color tone of.

For the toner, a positively or negatively chargeable charge control agent is used as required. Examples of the positively chargeable charge control agent include Bontron 03 which is a nigrosine dye of an azine compound and Bontron P which is a quaternary ammonium salt.
-51 (above, trade name of Orient Chemical Industry Co., Ltd.),
Quaternary ammonium salt molybdenum complex TP-302,
TP-415 (above Hodogaya Chemical Co., Ltd. product name),
Copy charge of quaternary ammonium salt PSY VP
2038, copy blue of triphenylmethane derivative
PR (above Hoechst brand name), LRA-901 (Nippon Carlit Co., Ltd. brand name), etc. are mentioned. Bontron S, a metal-containing azo dye, is used as a negative charge control agent.
-34, E-82 of oxynaphthoic acid type metal complex, E-84 of salicylic acid type metal complex, E of phenol type condensate
-89 (above, trade name of Orient Chemical Industry Co., Ltd.),
Copy charge of quaternary ammonium salt NEG VP
2036, Copy Charge NXVP434 (above, trade name manufactured by Hoechst), LR-147 which is a boron complex
(Trade name of Nippon Carlit Co., Ltd.) and the like. These charge control agents may be used alone or in combination,
It is preferable to add 5.0% by weight or less, particularly 0.5 to 3% by weight, to the toner. If the added amount exceeds 5% by weight, the charge amount is high and the printing density is low from the initial stage, the transferability from the photoconductor to the toner support is poor, and the cleaning property of the transfer residual toner adhering to the photoconductor is poor. There is a tendency for problems such as inferiority to occur.

Known silica powder may be further added to the toner. As the silica powder concerned, Aerosil (Aerosi
l) R972, R974, Silica D-17,
T-805, R-812, RA200, HRX-C (all manufactured by Nippon Aerosil Co., Ltd.), Taranox 500
(Manufactured by Tarco), Cab-o-Sil M-5, MS-
7, MS-75, HS-5, EH-5, S-17, TS
-72 (above, manufactured by Cabot).
When these are used, it is preferable that the content of the toner is 3% by weight or less.

In the present invention, the toner material containing the binder resin, the colorant, and other additives used as necessary is first dissolved or dispersed in an organic solvent in which the binder resin can be dissolved. Whether or not the binder resin can be dissolved depends on the type of binder resin, constituent components, molecular chain length, degree of three-dimensionalization, etc., so it cannot be said unequivocally, but generally toluene, xylene, hexane are used. Hydrocarbons such as methylene chloride, chloroform, dichloroethane, halogenated hydrocarbons such as dichloroethylene, ethanol, butanol, benzyl alcohol ethyl ether, benzyl alcohol isopropyl ether, tetrahydrofuran, tetrahydropyran and other alcohols or ethers, methyl acetate, ethyl acetate, Butyl acetate, ester such as isopropyl acetate, acetone, methyl ethyl ketone, diisobutyl ketone, dimethyl oxide, diacetone alcohol, ketone such as cyclohexanone, methylcyclohexanone,
Acetal or the like is used.

These solvents dissolve the binder resin, and it is not necessary to dissolve the colorant and other additives. The colorant and other additives may be dispersed in the binder resin solution. There is no limit to the amount of organic solvent used,
Any viscosity may be used as long as it can be granulated in an aqueous medium. Binder resin,
The ratio of the toner material (the former) and the solvent (the latter) containing the colorant and other additives used as necessary is 10 /.
90 to 50/50 (former / latter weight ratio) is preferable in terms of easiness of granulation and final toner yield.

A liquid of a toner material (toner mother liquor) containing a binder resin dissolved or dispersed in an organic solvent, a colorant, and other additives optionally used (toner mother liquor) is predetermined in the dispersion liquid for toner production. It is dispersed and granulated to have a particle size.
The mixing ratio of the dispersion liquid and the toner mother liquid is dispersion liquid / mother liquid = 90 /
10 to 50/50 (weight ratio) is preferable. The amount of the dispersion stabilizer used in the dispersion liquid is determined according to the particle size of the particles to be granulated, but is generally 0.
It is preferably used in the range of 1 to 15% by weight. 0.
If the amount is less than 1% by weight, the granulation is difficult to be performed well, and if the amount is more than 15% by weight, unnecessary fine particles are generated and it is difficult to obtain target particles in high yield. An auxiliary agent may be further added to the dispersion liquid in order to granulate the toner mother liquid well. Examples of such an auxiliary include known cation-type, anion-type and nonion-type surfactants, and anion-type surfactants are particularly preferable. For example, there are sodium alkylbenzene sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfonate, and the like, and these are 1 × 10 ^{−4 to} 0.
It is preferably used in the range of 1% by weight.

Granulation of the toner mother liquor in the dispersion is preferably carried out under high speed shear. The toner mother liquor dispersed in the dispersion is preferably granulated to have an average particle size of 10 μm or less. Particularly, 4 to 9 μm is preferable. If the particle size of the dispersion-granulated toner mother liquor is too large, it becomes difficult to achieve high resolution, or when the three primary colors in the case of a full-color toner are mixed to develop an intermediate color, the melting and mixing properties become insufficient and the intermediate color appears. It becomes difficult. There are various types of high-speed dispersers as devices equipped with the high-speed shearing mechanism, and of these, a homogenizer is preferable. The homogenizer allows substances that are incompatible with each other (in the present invention, an aqueous medium containing a dispersion stabilizer and a toner mother liquor) to pass through a narrow gap between the casing and a rotor that rotates at high speed, so that a certain liquid is made compatible with the liquid. This is a device for dispersing insoluble substances into fine particles. Examples of such homogenizer include TK homomixer, line flow homomixer (above, manufactured by Tokushu Kika Kogyo Co., Ltd.), Silverson homogenizer (manufactured by Silverson Co., Ltd.), Polytron homogenizer (manufactured by KINEMATICA AG), and the like.

The stirring conditions using the homogenizer are preferably at least 2 m / sec at the peripheral speed of the rotor blades. If it is less than this range, atomization tends to be insufficient. In the present invention, the solvent is removed after the toner mother liquor is granulated in the aqueous medium containing the dispersion stabilizer. The removal of the solvent may be carried out at normal temperature and pressure, but it takes a long time to remove it, and since the solvent remains in the toner particles and deteriorates the storage stability, it is lower than the boiling point of the solvent and the boiling point of the solvent. It is preferable that the temperature difference is 80 ° C. or less. The pressure may be normal pressure or reduced pressure, but it is preferable that the pressure is reduced to 20 to 350 mmHg.

It is preferable that the solvent is removed sufficiently until the particle shape of the granulated particles in the dispersion does not substantially change, and then the dispersion stabilizer is removed. In practice, it is preferable to remove 50% by weight or more, further 70% by weight or more, and especially 80% by weight or more of the total amount of the solvent charged. If the amount of the solvent to be removed is less than 50% by weight, when the dispersion stabilizer is removed, the granulated toner particles coalesce (a phenomenon in which the toner particles aggregate and become large particles), and the particle shape changes practically. In addition, it is difficult to obtain toner particles having a target particle size. The final toner particles are preferably controlled to have a residual solvent content of less than 1% by weight, particularly less than 0.5% by weight, from the viewpoints of environmental resistance, life at the time of mounting, prevention of toner adhesion to the photoconductor, and the like. Therefore, a step of further removing the solvent by vacuum drying, vibration fluidization drying or the like may be provided.

After removing the solvent, the obtained toner particles are preferably washed with an acid such as hydrochloric acid, nitric acid, formic acid, acetic acid or the like which reacts with tricalcium phosphate to solubilize these dispersion stabilizers. As a result, the dispersion stabilizer remaining on the toner surface can be removed, and the toner's original composition can be obtained. As a result, the charging characteristics of the toner can be maintained at a high level. In other words, by preventing the generation of undesired low-charged toner or reversely-charged toner, precise development can be performed on the electrostatic latent image, and image quality such as image density, resolution, gradation and fog can be improved. And shows excellent performance. Further, since the toner does not scatter, it does not pollute the working environment and is excellent in hygiene. Therefore, the toner and the developer which can be repeatedly used for a long time and have a long life can be obtained. Then, by dehydration and drying, powdery toner particles having an irregular shape can be obtained.

In order to further improve physical properties such as fluidity and chargeability, the obtained toner particles have the above-mentioned silica fine powder, vinyl-based (co) polymer, zinc stearate, on the surface of the toner particles, Fine particles such as aluminum oxide and titanium oxide may be further added and mixed as a toner external additive. When these toner external additives are added, they are preferably mixed in an amount of 0.05 to 5% by weight based on the toner before addition.
The toner thus obtained can be mixed with a carrier to form a developer. The type of carrier is not particularly limited, and well-known materials such as iron oxide powder, various ferrites, and magnetite can be used. The mixing ratio of the toner and the carrier is not particularly limited, and a known mixing ratio can be used. Generally, 1 to 10% by weight of toner is used in the developer. The obtained toner and developer can be used in various known developing means and fixing means.

[0029]

EXAMPLES The present invention will be described in detail below with reference to examples. Examples 1 to 10 (1) Production of Dispersion Liquid for Toner Production In a 30-liter reaction kettle equipped with a stirrer, ion exchanged water 8,576 g, methyl alcohol 409 g, sodium hydroxide 84 g (2.1 mol), phosphoric acid Trisodium 12
The hydrate 2,622 g (6.9 mol) was dissolved (saturation temperature of trisodium phosphate is about 32 ° C.). In a separate container, ion-exchanged water 8,053g, anhydrous calcium chloride 1,111g
(10 mol) was dissolved with heating and cooled to 32 ° C. to obtain an aqueous calcium chloride solution. Set the temperature of the reaction kettle to 32
While controlling the temperature to 1 ℃, add 1
The mixture was added dropwise over 0 to 15 minutes and further stirred at a temperature of 32 ° C. for 2 hours to complete the reaction. The concentration of tricalcium phosphate in the obtained dispersion was 5% by weight, and the average particle size of the crystals was 1.5 μm. This dispersion was designated as T-1.
Hereinafter, dispersions T-2 to T-8 were produced in the same manner as above except that the reaction conditions were changed as shown in Table 1.

[0030]

[Table 1]

(2) Production of styrene-acrylic resin In a cylindrical 2 liter flask equipped with a stirrer, a cooler, a thermometer, and a dropping device, 720 g of ion-exchanged water, 180 g of hydroxyapatite, and a 1% sodium dodecylbenzenesulfonate solution. 4.5 g was charged and the temperature was raised to 90 ° C. Next, 630 g of styrene and 270 butyl methacrylate
g and benzoyl peroxide 63 g were dissolved in the solution by a dropping device in 3 hours, and the reaction was completed by further stirring for 3 hours. The glass transition temperature of this product is 55 ° C (DSC
Method), the number average molecular weight (Mn) was 4,500, and the molecular weight dispersity (Mw / Mn) was 2.5 (gel permeation chromatography method, standard polystyrene conversion value).

(3) Production of polyester resin In a 2 liter separable flask equipped with a stirrer and a condenser for extracting condensed water, 780 g of terephthalic acid, 200 g of isophthalic acid, polyoxypropylene (2,2)-
2,2-bis (4-hydroxyphenyl) propane 86
0 g and 1.2 g of dibutyltin oxide were charged, the condensation reaction was allowed to proceed at 180 ° C. for 5 hours while blowing nitrogen gas, and then the reaction was further completed at 230 ° C. Glass transition temperature of this product 56 ° C (DSC method), number average molecular weight (Mn)
The molecular weight dispersity (Mw / Mn) was 3,000, which was 4 (gel permeation chromatography method, standard polystyrene conversion value).

(4) Preparation of toner mother liquor Binder resin, colorant, solvent and charge control agent shown in Table 2 are dispersed by a ball mill until the colorant particles become submicron,
A toner mother liquor was prepared.

[Table 2]

(5) Manufacture of Toner To 600 g of the dispersion prepared in (1) in a 1-liter cylindrical flask, 1 part of sodium dodecylbenzenesulfonate was added.
A 3% by weight aqueous solution and 200 g of a toner mother liquor (Table 3) were charged, and a homogenizer (TK Homomixer-M type manufactured by Tokushu Kika Co., Ltd.) was used, and a predetermined particle diameter was obtained under the conditions of a rotor peripheral speed of 6 to 8 m / sec. Oil droplets were granulated. Next, the solvent was distilled off under normal pressure to reduced pressure under a temperature condition lower than the boiling point of the solvent and the difference from the boiling point being 80 ° C. or less (solvent toluene,
Temperature 50-70 ° C, decompression degree 30-150 mmHg). After cooling, 12N hydrochloric acid was added until the pH reached 2, and the dispersion stabilizer was washed off, washed with water, dried and classified to have an average particle size of 4.3.
A solid amorphous toner of ˜6.3 μm was obtained. As an external additive treatment, silica powder (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts by weight of the obtained toner.
0.2 parts by weight was added and mixed by stirring with a Henschel mixer.

(6) Evaluation Copper-zinc ferrite carrier 95 coated with 5% by weight of toner and a methyl methacrylate resin and having an average particle size of 60 μm
The developer consisting of weight% is used in the copying machine Recopy FT-75.
70 (manufactured by Ricoh Co., Ltd.) was continuously printed in an environment of 35 ° C. and 70% relative humidity to evaluate image quality, workability and the like. The results are shown in Table 3. (A) Reproducibility of color tone: Printing was performed on Mylar paper, the reproducibility of a color image was examined with an OHP (overhead projector), and evaluated according to the following criteria. Good: A chromatic color is expressed and an intermediate color is also expressed. Poor ... Chromatic color does not appear. (B) Image density, fog and resolution Image density and fog were measured using a Macbeth reflection densitometer RD514 type (A division kollmorgen Corp.),
Regarding the resolution, the image was magnified 10 times, and it was visually determined how many lines were resolved per inch. (C) Toner scattering The presence or absence of toner scattering was visually determined. (D) Cleaning Property The transfer residual toner on the photoconductor that passed through the cleaning process was transferred to a blank sheet of paper with Scotch tape (manufactured by Sumitomo 3M Ltd.), and measured with a Macbeth reflection densitometer RD514 type and compared with a blank. The case where the difference from the blank was 0.04 or less was evaluated as good, and the case where the difference was more than 0.04 was evaluated as bad.

[0036]

[Table 3]

Example 11 The toners of Examples 1, 2 and 3 were put in Konica Digital Full Color 9028 (manufactured by Konica Corp.), and after the initial image was adjusted and printing was performed, intermediate colors were accurately reproduced and were excellent. The image quality was excellent.

Comparative Example 1 The binder resin, pigment and charge control agent of Example 1 were premixed with a Henschel mixer and then melt-kneaded with a biaxial kneader. Then, the cooled kneaded product was subjected to pin mill and jet mill to obtain an irregular toner having an average particle size of 8 μm, and further 0.2 g of Aerosil R972 (manufactured by Nippon Aerosil Co., Ltd.).
As a result of mixing in a Henschel mixer in an amount of 10% by weight, the color tone reproducibility was inferior at the beginning, the image density was 1.2, the fog was 0.1, the resolution was 6.3, the toner was not scattered, and the cleaning property was good. After printing 50,000 pages, the color reproducibility was poor, the image density was 0.8, the fog was 0.15, the resolution was 4.0, the toner was scattered, and the cleanability was good. Further, the yield of the toner was as low as 60% by weight with respect to the yield of the toner of the present invention of 80 to 95% by weight.

Comparative Example 2 An aqueous solution containing the dispersion stabilizer of Example 1 was mixed with polyvinyl alcohol (Denka Poval W-24 (Denka Kagaku Co., Ltd.).
3% by weight aqueous solution) was used to obtain a spherical toner having an average particle size of 6 μm and the performance was evaluated in exactly the same manner, except that the color reproducibility was poor in the initial stage (no light transmission). ), Image density 1.2, fog 0.1, resolution 6.3, toner scattering, and good cleanability, and were not stable to the environment. After printing 5,000 pages, the color reproducibility is poor (light does not pass), and the image density is 0.
8, fogging 0.2, resolution 4.0, toner scattering, and cleaning property were poor. The yield of the toner was 20% by weight, which was extremely low compared to the yield of the toner of the present invention of 80 to 95% by weight.

Comparative Example 3 An aqueous solution containing the inorganic dispersant of Example 1 was produced by a method different from the method shown in the present invention, and commercially available hydroxyapatite (trade name: Supertite 10, Nippon Kagaku Co., Ltd.). Except that the solid content concentration was adjusted to 5% by weight, and an irregular toner having an average particle diameter of 20 μm was obtained in the same manner as in Example 1. This is because the toner particle size is large and the toner cannot be evaluated.

Comparative Example 4 The toner dispersion T-1 used in Example 1 was replaced with T-8.
When changed to, the average particle size of the oil droplets during granulation was 5.9μ.
m, the toner average particle size after desolvation is 5.4 μm,
The toner has a large particle size.

[0042]

As is clear from the above results, when a toner is manufactured using the toner manufacturing dispersion liquid of the present invention, a toner having a small particle size which maintains excellent image quality for a very long period of time is improved. It can be obtained in yield.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chiaki Okada 4-13-1, Higashimachi, Hitachi, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Yamazaki Plant

Claims (5)

[Claims] 1. Toner particles are manufactured by dispersing and granulating a liquid obtained by dissolving or dispersing a toner material containing a binder resin and a colorant in an organic solvent capable of dissolving the binder resin in an aqueous dispersion liquid. A dispersion liquid for toner production, comprising tricalcium phosphate as a dispersion stabilizer, which is obtained by reacting trisodium phosphate and calcium chloride in an alkaline water-alcohol medium. 2. The dispersion liquid for toner production according to claim 1, wherein the average particle diameter of tricalcium phosphate in the dispersion liquid is 0.5 to 4 μm. 3. The dispersion liquid for toner production according to claim 1, wherein the alcohol contained in the alkaline water-alcohol medium is alkyl alcohol, glycol or glycerin. 4. A method for producing the dispersion liquid for producing a toner according to claim 1, wherein 6 to 7.5 mol of trisodium phosphate is mixed with 10 mol of calcium chloride and the mixture is reacted. A method for producing a dispersion for producing a toner. 5. The toner manufacturing dispersion according to claim 1, wherein a toner material containing a binder resin and a colorant is dissolved or dispersed in an organic solvent capable of dissolving the binder resin. A method for producing a toner for developing an electrostatic charge image, comprising dispersing and granulating particles to produce particles, and then removing a solvent from the particles.