JPS63231360A - Method for producing toner for developing electrostatic images - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a toner for electrostatic image development used in electrophotography, electrostatic recording, electrostatic printing, and the like.

[Prior art and problems]

Conventional toners for developing electrostatic images include cargane black, phthalocyanine blue, carmino 6B, benzidine yellow,
It is produced by mixing a pigment such as magnetite with a Pai Gou resin, melting and kneading the mixture, cooling it, pulverizing it, and classifying it to obtain particles with a particle size distribution of 5 to 25 microns and an average particle size of 10 to 15 microns.

Various additives are mixed as necessary to impart the necessary properties to the toner. For example, metal-containing azo dyes and the like are used to control the level of triboelectric charging that occurs when toner is mixed with carrier. In addition, waxes are added during melt mixing to prevent the paper from wrapping around the heat roll for fixing and from offset.

The shape of conventional toner produced by pulverization and classification is generally irregular and angular, resulting in poor fluidity as a powder. As a powder fluidity improver, hydrophobic silica fine powder having a primary particle diameter of 10 to 100 m[mu] is often externally added to toner (triblend). Magnetic toner particles containing a magnetic substance such as magnetite are magnetically attached to the fA1A1 resleeve covering the magnet roll to form a magnetic brush. A magnetic brush is formed by mixing a toner containing no magnetic material (non-magnetic toner) with a magnetic material generally called a carrier and having a particle size of 30 to 200 .mu.m.

The state of the magnetic brush, especially the state of its contact with the photoreceptor surface, has a great effect on the development rate. If the condition is poor, fading may occur in one image or the density of solid areas may deteriorate. Although the magnetic properties of the carrier or the magnetic material contained in the magnetic toner are important factors related to the state of the magnetic brush, the biggest factor is the powder fluidity of the toner and carrier.

This is particularly noticeable when high-speed development is performed at 50 sheets per minute (A-4) or more. As mentioned above, toner manufactured by the conventional pulverization/classification method has an amorphous and angular shape, and therefore has poor powder fluidity, which has a negative effect on the condition of the magnetic brush.

In addition, conventional toners that are irregularly shaped and have poor fluidity tend to form prep in the toner production process or process, and have the disadvantage that it is difficult to mix the toner and carrier.

Traditionally this drawback? In order to cover this problem, the method of tri-blending all fluidity modifiers such as hydrophobic silica fine powder as mentioned above is widely adopted, but this method is not preferable from the viewpoint of maintaining the stability of the toner charge amount. In fact, since the amount added is limited, a toner with satisfactory fluidity cannot be obtained. In order to solve these problems with conventional toners, a suspension polymerization method is used in which a mixture of addition polymerizable monomers containing toner components is dispersed in water using a high shear force TK homomixer (manufactured by Tokushu Kogyo ■). Although techniques for producing spherical toner have been proposed, it has not yet been possible to obtain toner having a fine average particle size and a sharp particle size distribution that can be put to practical use.

In addition, the resolution of the developed image, the density of the peta area, and the gradation reproducibility are largely dependent on the characteristics of the toner and carrier, especially the particle size of the toner.The smaller the particle size, the higher the image quality. Attempts have been made to select a toner particle size within a range of 1 μm to 15 μm and an average particle size of 1 μm to 15 μm.

However, with conventional toner manufacturing technology using pulverization and classification, the average particle size is 10 μm or less, and the particle size distribution is 1 μm or more.
It is impossible to obtain toner in the range of 20 μm with a yield of 50% by weight or higher, and a manufacturing method that can produce toner with an arbitrary average particle size of 10 μm or less in high yield is strongly desired. There is.

As a means to solve this problem, a suspension polymerization method in which a mixture of addition polymerizable monomers containing toner components is dispersed in water using an ultrasonic homogenizer is used to produce fine particles (1 to 15 μm).
Although the technique for obtaining spherical toner is useful, each ultrasonic irradiation device can only irradiate ultrasonic waves at a certain frequency, and the obtained toner can only have a certain average particle size.
Obtaining toner with an arbitrary average particle size within the range of 15 μm requires enormous equipment, making commercialization difficult.

[Means for solving problems]

The present invention eliminates the drawbacks of the conventional toner manufacturing methods and provides a toner manufacturing method that has a practically sharp particle size distribution and can arbitrarily select an average particle diameter.

That is, in the present invention, a polymerizable mixture in which materials contained in toner such as dyes, pigments, and waxes are dissolved or classified in addition polymerizable monomers is dispersed in water using a single sonic homozonation device, and then suspended. In a method for producing a toner formed by turbid polymerization, a weight average molecular weight of 6 that can be dissolved in an addition polymerizable monomer is used.
Sharp particle size characterized by using a toner by a method in which a mixture of 00 to 500,000 polymers of 1 to 70 weight Ilt is dissolved in advance, dispersed in water using an ultrasonic homogenizer, and then subjected to suspension polymerization. The object of the present invention is to provide a method for producing an electrostatic image toner which has a distribution and can arbitrarily select an average particle size.

Although there are no particular limitations on the ultrasonic homogenizer used in the present invention, an ultrasonic homogenizer with a frequency of 10 to 50 kHz is used to achieve a processing capacity of 0.1 to 3 per unit time.
0 (W/2/1(R) O irradiation fTe is preferably dispersed in water.

In the present invention, the irradiation method using an ultrasonic homogenizer is not limited by the irradiation device; for example, an ultrasonic homogenizer may be used inside the suspension polymerization container.

A method of installing a dispersion tool (horn) and irradiating ultrasonic waves continuously or intermittently before or during suspension polymerization, irradiating ultrasonic waves to suspend toner components to be polymerized. During polymerization or! Any method may be used in which ultrasonic irradiation is performed by passing a cell containing an ultrasonic dispersion tool through two or more chambers one after another before turbidity polymerization.

The present invention is not limited by the method of dissolving or dispersing the materials contained in the toner such as dyes/pigments, waxes, and polymers having an average molecular i of 600 to 500,000 in the polymerizable half-lid; for example, Any of the sol mill attritor, vibration mill, sand mill, three-roll mill, ultrasonic homogenizer, etc. used for general solid-liquid dispersion may be used.

In the present invention, the following addition polymerizable monomers are used in suspension polymerization.

In other words, styrene, "" *m-+ Styrenes and their derivatives such as p-methylstyrene and p-butylstyrene, ethylenically unsaturated mono-V fins such as ethylene and butylene, vinyl chloride, vinyl bromide, etc. Tsubaki C1f Vinyl esters such as vinyl chloride, vinyl acetate, vinyl propionate, methacrylic acid esters such as methacrylic acid and methyl hypomethacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, β-hydroxyethyl methacrylate , acrylic acid and methyl acrylate,
Acrylic acid esters such as ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and β-hydroquine globyl acrylate, vinyl ethers such as vinyl methyl ether and vinyl ethyl ether, vinyl methyl chtone, and vinyl hexyl ketone. vinyl ketones such as N-vinylpyrrole, N-vinyl compounds such as N-vinylcarbazole, vinylnaphthalenes, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylnitrile, acrylamide, hexamaric acid and dimethyl fumarate, dimethyl Hepmalic acid and fumaric acid alkyl esters such as til fumarate, so-2-ethylhexyl heptamate, maleic acid, maleic anhydride, and dimethyl maleate, diptyl maleate, motuptyl maleate, etc., thumaric acid, maleic anhydride, and hismaleic acid. These monomers include acid alkyl esters, and these monomers may be used alone or as a mixture in any combination.

In the present invention, a divinyl compound as a polymerizable crosslinking agent shown below may be used in combination with the addition polymerizable monomer mixture. Namely, divinylbenzene, divinylnaphthalene, divinyl ether, divinyl sulfone, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene. glycol dimethacrylate)
, 1.6-hexane gelicol dimethacrylate, neopentyl glycol dimethacrylate, diethylene glycol diacrylate, polypropylene glycol dimethacrylate, 2.2'-bis(4-methacryloxyjethoxyphenyl)propane, 2.2'-bis Examples include (4-acryloxyjethoxyphenyl)furogun, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, dibromneopentylglycol dimethacrylate, and diallyl heptatalate.

The initiators used in the suspension polymerization in the present invention include known initiators, such as azobisinobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, ingropyl peroxycargenate, xymen hydroperoxide, 2,4 Examples include -dichlorobenzoyl peroxide, lauroyl peroxide, and the like, and are not limited by the type thereof.

In the present invention, the weight average molecule ji dissolved in the addition polymerizable monomer is 600 to 500,000, preferably 1.00.
Examples of the polymer having a molecular weight of 0 to 300,000 include homopolymers or copolymers of the polymerizable monomers described above, such as polystyrene, polyacrylic ester, polymethacrylic ester, polybutadiene, polyvinyl chloride, polyvinyl acetate, Homopolymers such as polyacrylamide and polyacrylonitrile, styrene-acrylic ester, styrene-methacrylic ester, vinyl chloride-vinyl acetate copolymer, styrene-acrylic ester-methacrylic ester, styrene-acrylic ester
Multicomponent copolymers of arbitrary combinations such as tri- and quaternary copolymers such as diptyl fumarate, ethyl cellulose, nitrocellulose, cellulose acetate), rosin, oxidized rosin and these Esters and at least partially hydrogenated esters thereof, saturated and unsaturated polyester resins, alkyd resins, epoxy J
ttJj! , urethane resins, phenol resins, urea resins, melamine resins, guanamine resins represented by benzoguanamine, xylene resins, indene resins, petroleum resins, silicone resins, butyral resins, and other polymers that can be dissolved in polymerizable monomers. Either is fine. As mentioned above, the polymer to be dissolved in the polymerizable monomer is not limited by its cage, but if a polymer with a small molecular weight is used, it is inappropriate because it impairs the heat-resistant cohesiveness of the resulting toner. Also, if the molecular weight is too large, it will inhibit the dispersion and micronization by an ultrasonic homozonizer, making it unsuitable and resulting in a heavy average molecule! 600-500,000 polymers are preferred. Further, the k of the 4-limer to be dissolved is 1 to 70% by weight in the mixture with the monomer, and if the amount is too small, the toner particle size cannot be controlled sufficiently, and if the amount is too large, the fine particles that can be used as a toner will be Unable to obtain particle size. As the colorant used as a toner component in the present invention, known pigments and dyes can be used. For example, pigments are
Black pigments include channel black, furnace black, thermal black, acetylene black, etc.
Coloring pigments include cadmium yellow, hump yellow G, naphthol yellow S, pyrazolone red,
No. 9-mane/to red 4R, molybdenum orange, astoviolet) B, 7 thalocyanine blue B, first sky blue, phthalocyanine green, malachite green, naphthol green B, etc.

In addition, as dyes, C,1, Direct Red 1, C,
I, Direct Red 4, C, I, Acid Red 1,
C,I, Basic Red 1, C0I, -Modern Red 30, C,I, Direct Blue 1%C,1, Direct Blue 2, C,1, Acid Blue 9, C,I
, Acid Blue 15, C, I, Basic Blue 3,
C, 1, Bentzk Blue 5, C, I, Mordand Bruer, C, I.

Direct Green 6, C, 1, Basic Green 4
, C,1, Basic Green 6, etc.

In the present invention, since the toner is used as a magnetic toner, it may contain magnetic powder. Examples of such magnetic powder include powders of ferromagnetic metals such as iron, cobalt, and nickel, or powders of alloys and compounds such as magnetite, hematite, and ferrite. The amount of violet contained in these magnetic powders is preferably 15 to 70 times the weight of the toner.

Additionally, additives such as a charge control agent, a fluidizing agent, a cleaning agent, and a filler may be added to the toner raw material components as necessary.

Charge control agents that give positive charge include nigrosine dyes, alkoxylated amines, quaternary ammonium salts, alkylamides, simple substances and compounds of phosphorus and tungsten, molybdate chelate pigments, fluorine-based activators, and hydrophobic Silica etc. are used. Those that give negative charge include metal complexes of monoazo dyes, electron-accepting organic complexes, chlorinated polyolefins, chlorinated polyesters, polyesters with excess acid groups, sulfonylamines of copper phthalocyanine,
Oil black, naphthenic acid metal salts, fatty acid metal salts,
There are resin acid soaps, etc.

Examples of fluidity modifiers include colloidal silica, hydrophobic silica, silicon face, metal soap, nonionic surfactants, and polyvinyl fluoride fine particles. Cleaning agents include metal salts of fatty acids such as aluminum stearate, calcium stearate, zinc stearate, and zinc laurate. Other types include colloidal powder, polytetrafluoroethylene resin powder, etc.

Fillers include calcium carbonate, clay, lilac, soft pigments, kaolin, silica, and the like.

In addition, waxy substances such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, Sasol wax, etc. may be added in an amount of about 0.5 to 15 weight cents to improve mold release properties during hot roll fixing. You can also do it. Note that the charge control agent and fluidity modifier may be used in combination with the obtained toner particles.

In the present invention, suspension polymerization is not limited by the use of suspension stabilizers, and commonly used suspension stabilizers such as those described below can also be used. For example, organic suspension stabilizers include polyvinyl alcohol, gelatin,
Methylcellulose, methylhydropropylcellulose, ethylcellulose, droxyethylcellulose, sodium salt of calgeoxymethylcellulose, polyacrylic acid and their salts, starch, f-alginate,
Casein, inorganic suspension stabilizers include tricalcicum phosphate, Merck, barium sulfate, bentonite, aluminum hydroxide, ==nium ferric hydroxide, titanium hydroxide, calcium hydroxide, alumina, colloidal silica, etc. It can be used by incorporating it into the phase.

Further, as an auxiliary dispersant for the suspension stabilizer, the amount of 0.001 to 0.
Surfactants within the range of 1% by weight may be used.

Furthermore, when carrying out suspension polymerization in the present invention, the use of a chain transfer agent typified by, for example, dodecyl mercaptan is also included in order to adjust the molecular weight.

〔Example〕

Next, the present invention will be explained in further detail by showing Examples.

Note that parts and parts in the examples represent parts by weight and parts by weight.

Comparative Example-1 70 parts of styrene, 10 m of butyl acrylate, 20 parts of methyl methacrylate, 1 part of divinylbenzene, 5 parts of Elftex-8 (Car & N Black manufactured by Camet)
1 part, Viscol 550P (polyprene wax manufactured by Sanyo Chemical Co., Ltd.), 2 parts of Pintron S-34 (charge control agent manufactured by Orient Chemical Co., Ltd.), 2 parts of azobisinobutyronitrile, and 1 part of dodecyl mercaptan in a beaker. Without stirring, the mixture was dispersed using an ultrasonic homogenizer at 600 W and a frequency of 14°5 kHz. In a separate container equipped with a $74 type stirring blade, 500 parts of ion-exchanged water was charged, and the above polymerizable mixture was added to the dispersion suspension. Made it muddy. This again is 317
The mixture was charged into a reaction vessel equipped with a paddle-type stirring blade while being subjected to ultrasonic treatment at a flow rate of m. The inside of the reaction vessel was purged with nitrogen, the temperature was immediately raised to 80°C, and polymerization was carried out with stirring for 5 hours. Next, the polymer was temporarily dried to obtain a toner powder. The obtained toner has a volume average particle diameter of 0.8 μm and 0.4 to
It contained 70% particles in the 3 μm range.

Comparative Example 2 A toner was produced in exactly the same manner as in Comparative Example 1, except that the toner mixture was predispersed in 500 g of ion-exchanged water using a paddle-type stirring blade, and the toner was subjected to ultrasonication at a rate of 6 t/iI. The toner had a volume average particle diameter of 6 μm, a number average particle diameter of 2 μm, and a broad particle size distribution. Transfer 40 parts of this toner to a ferrite carrier T manufactured by TDK.
A developer was prepared by mixing with FC-381,000 parts, and when this developer was developed using Toshiba's high-speed copying machine RheoDry 8801Th, the resolution, gradation, and density of the peta area were poor, and 10,000 sheets could be printed. Results of continuous copying test of IJ
-I had bad Jungian traits.

Comparative Example 3 In Comparative Example 2, the toner component mixture was pre-dispersed in 50 liters of ion-exchanged water using a stirrer type stirring blade, at a speed of 81/-, at a speed of 600 W and at a frequency of 20 k (except for the ultrasonic treatment of z). A toner was produced in exactly the same manner.The resulting toner had a volume average particle size of 12 μm, a number average particle size of 4 μm, and a 10-degree particle size distribution.

Synthesis Example 1 160 parts of styrene, 26 parts of n-butyl acrylate, M
MA 16 parts, ion exchange water 300 parts, benzoyl peroxide 2 parts, Poval PAO5 (manufactured by Shin-Etsu Chemical) 2
The mixture was placed in a flask equipped with a thermometer, a stirring bar, and a nitrogen inlet tube, and suspension polymerization was carried out at 90° C. for 15 hours under a nitrogen stream, and the resulting pearl-like product was washed with water and dried. The polymerization average molecular weight of the obtained polymer was 3×10.

Synthesis Example 2 In Synthesis Example 1, penzoylno! A resin was synthesized in exactly the same manner except that 0.1 part of -oxide was added instead of 2 parts, and the weight average molecular value of the resulting polyester was 3 x 10.

Synthesis Example 3 200 parts of styrene were placed in a 5-72 tube equipped with a thermometer, a stirring bar, and a nitrogen inlet tube, and the temperature was raised to 130°C under a nitrogen stream. Next, 170 parts of styrene, 30 parts of n-butyl acrylate, and After dropping a homogeneous solution of 14 parts of oxide over 2 hours while keeping the temperature inside the flask at 130°C,
Polymerization was carried out for a period of time, and then the mixture was heated to 200° C. and reduced in pressure to distill off the cylene. The weight average molecular value of the obtained polymer was 7×10.

Synthesis Example 4 Polyquinepropylene (22 mol)-2,2-bis(4
-Hydroxyphenyl)furopane 740! , 230 parts of terephthalic acid, and 4 parts of tetrabutyl titanate were placed in a glass four-piece flask, equipped with a thermometer, a stirring rod, and a nitrogen introduction tube, and heated at 220° C. with an electric heating mantle under a nitrogen stream until the acid value reached 15 KOHmy/9. I reacted. The weight average molecular value of the obtained polyester resin was 6,000.

Example 1 A toner was produced in exactly the same manner as in Comparative Example 1 except that 10 parts of the polymer obtained in Synthesis Example 1 was added as a toner component. The volume average particle size of the obtained toner was 6μ.
m, number average particle size is 4. I Am, 4-8 μm
The toner contained 80% particles in the range of , and had a sharp particle size distribution. This toner? A developer was prepared in exactly the same manner as in Comparative Example 2, and a development test was conducted, and a high-quality image was obtained with extremely good resolution, gradation, and solid area density, and no blurring or capri. Also, 35℃, 851RH
There was no change in image quality in a high humidity environment, and the results of a continuous copying test of 10,000 sheets showed good cleaning performance and almost no change in image quality.

Example 2 Polymer 1-15 obtained in Synthesis Example 1 in Example 1
Is it the same as the toner except for adding a part? Manufactured.

The obtained toner had a volume average particle size of 10 μm, a number average particle size of 9.2 μm, and contained 75 particles in the range of 8 to 12 μm, resulting in a toner with a sharp particle size distribution. Further, this toner was tested in the same manner as in Example 1, and the results were good as in Example 1.

Example 3 A toner was produced in exactly the same manner as in Example 1 except that 30 parts of the polymer obtained in Synthesis Example 3 was added. The obtained toner has a volume average particle size of 11.5 μm, a number average particle size of 10.4 μm, and a range of 9.5 to 13.5 μm.
A toner with a sharp particle size distribution containing 76% of particles in the range was obtained. Further, this toner was tested in the same manner as in Example 1, and the results showed that it was good and the offset property was also good.

Example 4 A toner was produced in exactly the same manner as in Comparative Example 3 except that 3 parts of the polymer obtained in Synthesis Example 2 was added as a toner component and the toner was subjected to ultrasonic treatment at a speed of 31/-. The obtained toner has a volume average particle size of 11 μm and a number average particle size of 10.2 μm, with 74 particles in the range of 9 to 12 μm.
A toner with a sharp particle size distribution was obtained. Further, this toner was tested in the same manner as in Example 1, and the results showed that it was good.

Example 5 A toner was prepared in exactly the same manner as in Example 4, except that 40 parts of the polymer obtained in Synthesis Example 4 was added instead of the polymer obtained in Synthesis Example 2. Manufactured. The obtained toner has a volume average particle size of 12 μm, a number average particle size of IL, 2
A toner with a sharp particle size distribution containing 76% of particles in the range of 10 to 14 μm was obtained. Moreover, as a result of testing this toner in the same manner as in Example 1, the offset property,
The results were good including fixability.

Example 6 70 parts of styrene, 10 parts of butyl acrylate, 20 parts of methyl methacrylate, 85 parts of Elkutex, 4 parts of Viscol 550P, 2 parts of Pontron 5-34,
A toner was produced in exactly the same manner as in Comparative Example 1 using 0.2 parts of BPO and 100 parts of the posamer obtained in Synthesis Example 3. The obtained toner had a volume average particle size of 11.5 μm,
The number average particle diameter is 10.2 μm, 9.5 to 1j, 5
A toner with a sharp particle size distribution containing 73 particles in the μm range was obtained. Also, this toner? As a result of testing in the same manner as in Example 1, the results were good including offset properties and fixing properties.

Example 7 A toner was produced in exactly the same manner as in Example 6, except that Epiclon 4050 (manufactured by Dainippon Ink Chemical Co., Ltd., Bisphenol Affi Evokin m fat>50g1) was used in place of the polymer of Synthesis Example 3.

The obtained toner has a volume average particle size of 10.54 m1, a number average particle size of 9.1 μm, and a particle size of 7.2 to 1[,2 μm].
A toner with a wide particle size distribution containing 72 particles in the range of was obtained, and this toner was tested in the same manner as in Example 1 and found to be good.

〔effect〕

According to the manufacturing method of the present invention, it is possible to obtain a toner having a practically usable and sharp particle size distribution and also having an arbitrary particle size.

Claims (1)

[Claims] A polymerizable mixture in which materials contained in toner such as dyes, pigments, and waxes are dissolved or dispersed in addition polymerizable monomers is dispersed in water using an ultrasonic homogenizer, and then suspension polymerized. In the toner manufacturing method, a weight average molecular weight of 600 to 500, which can be dissolved in the addition polymerizable monomer,
1. A method for producing a toner for developing an electrostatic image, characterized by using a polymerizable mixture in which 1 to 70% by weight of 000 polymer is dissolved in advance.