JPS63235957A - Two-component developer - Google Patents

Abstract

PURPOSE:To secure superior fluidity and cleanability by using a toner obtained by kneading and pulverizing a binder resin and additives, applying mechanical impact energy to the obtained resin particles, and forming them into spheres without pulverizing them. CONSTITUTION:The binder resin and other additives used when needed are kneaded and pulverized, and the obtained resin particles are repeatedly given mechanical impact energy in a gas phase and formed into spheres substantially without being pulverized, thus permitting the obtained toner to be enhanced in fluidity, to exhibit superior developing performance, and not to cause poor cleaning.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-component developer comprising a toner and a carrier used in electrophotography, electrostatic recording, electrostatic printing, and the like.

[Background of the invention]

In general, in electrophotography, a uniform electrostatic charge is applied to a latent image carrier, i.e., a photoreceptor, which has a photosensitive layer made of a photoconductive material, and then image exposure is performed to create an electrostatic potential on the surface of the photoreceptor. An image is formed, and this electrostatic latent image is developed with a developer to form a toner image. The obtained toner image is transferred to a transfer material such as paper and then fixed by heating or pressure to form a copy image.

Wet developing methods and dry developing methods are known as methods for developing electrostatic latent images. The former wet development method uses a liquid developer, which has the problem of emitting a bad odor, and also requires high energy to dry the transfer material, making high-speed copying difficult. The latter dry developing method does not have such problems and is a preferred method for developing electrostatic latent images.

The developers used in the dry development method are generally one-component developers consisting only of magnetic toner containing a magnetic substance, and so-called one-component developers consisting of a non-magnetic toner containing no magnetic substance and a magnetic carrier. Two-component developers are known.

The latter two-component developer triboelectrically charges the toner by mechanically stirring the toner and carrier.
By selecting carrier characteristics, stirring conditions, etc.
It is possible to control the charge polarity and charge amount of the toner to a considerable extent, and there is a wide selection range of colors that can be imparted to the toner, and these are superior to the former one-component developer.

However, in a two-component developer, when the fluidity of the toner is low, only the lower part of a single layer of toner falls out in the developing device or replenishment hopper, forming a bridge at the upper part and not falling to the lower part ( Kamakura phenomenon) occurs,
Further, there is a problem that an appropriate amount of toner cannot be stably conveyed to the developing space, resulting in a decrease in image density or occurrence of image unevenness.

In addition, if the fluidity of the toner is low, the toner tends to form agglomerates, which prevents the toner from being properly tribo-electrified.As a result, the final fixed image becomes foggy and unclear. be.

Conventionally, in order to improve the fluidity of toner, a fluidizing agent such as silica is added to and mixed with toner. However, when adding and mixing a fluidizing agent such as silica, there are the following problems.

(1) Since fluidizing agents such as silica are highly susceptible to the influence of humidity, the toner becomes highly dependent on the environment, and the image quality deteriorates considerably, particularly under high temperature conditions.

(2) Because fluidizing agents such as silica are hard, they easily scratch the surface of the latent image carrier, making it difficult to clean the fluidizing agent such as silica, and as a result, the remaining fluidizing agent such as silica becomes a nucleus. As a result, toner adheres to this, causing dot-like stains (black spots) on the copied image.

(3) Since fluidizing agents such as silica have a relatively large triboelectric charging ability, the triboelectric charging ability of toner is easily inhibited (
, the resulting image quality deteriorates.

(4) Since the surface of the toner is covered with a fluidizing agent such as silica, the fluidizing agent such as silica exhibits a heat insulating effect during the toner fixing process, resulting in poor fixability.

For this reason, it has been proposed to make the toner spherical in order to improve the fluidity of the toner. Conventionally, the following spheroidization techniques have been proposed.

(1) A technique in which the surface of resin particles obtained by kneading and pulverization is melted with hot air using a spray dryer to make them spherical (JP-A-56-52758, JP-A-59-1)
(See Publication No. 27662).

(2) A technique of manufacturing toner particles by a granulation polymerization method to make them spherical (see Japanese Patent Laid-Open No. 121048/1983).

(3) Technology of dispersing resin particles obtained by kneading and pulverization into an air stream and melting their surfaces to make them spherical (Japanese Unexamined Patent Publication No. 5
8-134650).

(4) A technique for simultaneously pulverizing a coarsely pulverized toner composition and sphericalizing it by controlling the temperature of incoming air (see Japanese Patent Laid-Open No. 61-61627).

[Problem that the invention seeks to solve]

However, in the technique (1) above, when melting with hot air etc., the dispersion state of the resin particles is not completely uniform, and agglomeration of the resin particles occurs due to contact between resin particles. As a result, the average particle size of the resulting toner increases, leading to deterioration in image quality, and the particle size distribution widens, resulting in a significant decrease in yield when obtaining toner with a desired particle size distribution, and the production of toner. There is a problem that the cost increases.

In the technique (2) above, since the granulation polymerization method is adopted, the range of resins that can be selected as the binder resin is narrow, which is disadvantageous, and it is also difficult to uniformly disperse and contain magnetic fine particles in the resin particles. As a result, the magnetic properties of the resulting magnetic toner become uneven, resulting in various problems such as toner scattering and uneven development.

In the technique (3) above, it is possible to obtain spherical toner particles with considerably high precision, but on the other hand, the spherical formation becomes excessive, which tends to result in poor cleaning of the toner. That is, in the cleaning process, toner remaining on the surface of the latent image carrier is usually scraped off with a blade or the like, but toner with a high degree of sphericity is rubbed between the surface of the latent image carrier and the blade. There is a problem that the toner easily comes off, and as a result, a portion of the toner remains on the latent image carrier, adversely affecting the formation of the next copy image, resulting in an unclear image.

In the technique (4) above, in order to simultaneously perform pulverization and spheroidization, the temperature of the incoming air is set to the glass transition point of the resin.
As a result, the plastic deformation of the resin becomes large and the crushability deteriorates. Therefore, there is a problem in that a large amount of energy is required to pulverize the particles to a desired particle size, which increases manufacturing costs. Furthermore, due to the high temperature, a phenomenon occurs in which the pulverized material fuses to the wall of a device such as a pulverizer, making it difficult to efficiently obtain toner with a desired particle size distribution.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its purpose is to provide a product with high fluidity and excellent developability, without causing poor cleaning, and with low environmental dependence. The object of the present invention is to provide a two-component developer that can stably form high-quality images and efficiently obtain a desired particle size distribution.

[Means for solving problems]

The two-component developer of the present invention is a two-component developer consisting of a toner and a carrier and to which no fluidizing agent is added, wherein the toner contains a binder resin and other additives used as necessary. However, by repeatedly applying mechanical energy by impact force in the gas phase to the resin particle powder obtained by kneading and pulverizing, it was confirmed that the resin particles were spheroidized without substantially pulverizing the resin particles. Features.

[Function and effect of the invention]

According to the two-component developer of the present invention, the toner has high fluidity and exhibits excellent developability, does not cause poor cleaning, has low environmental dependence, and has good properties without producing black spots. Images of high quality can be stably formed, and toner with a desired particle size distribution can be efficiently obtained.

That is, the toner is produced by repeatedly applying mechanical energy through impact force in a gas phase to resin particle powder obtained by kneading and pulverizing a binder resin and other additives used as necessary. Since the resin particles are sphericalized without being substantially crushed, the toner particles are moderately spherical without the risk of being excessively spherical, resulting in excellent fluidity and excellent fluidity. Demonstrates cleaning properties.

In addition, the amount of mechanical energy mainly due to the impact force applied to the resin particles for sphericalization is smaller than the energy required in the normal pulverization process, so the amount of mechanical energy required to manufacture the toner is sufficient. Low cost (
is advantageous and does not require high temperatures.
There is little risk of the toner particles becoming larger in diameter due to heat fusion, etc., and since the spheroidization process is performed after the pulverization process, there is less generation of fine powder during the spheroidization process, and it is possible to efficiently produce particles with the desired particle size distribution. can be obtained.

Furthermore, since high temperatures are not required in the spheroidization process, the desired stable characteristics are exhibited without causing thermal deterioration of the resin and other additives used as needed.

In addition, since it does not contain a fluidizing agent such as silica, the developer has low environmental dependence, and can form images of good quality even under high temperature and high humidity conditions. Damage is reduced and image stains such as black spots are prevented from occurring, and there is less risk of the toner's triboelectric charging properties being inhibited, resulting in good developing performance.Also, good fixing performance is achieved in the toner fixing process. Demonstrated.

[Specific structure of the invention]

The present invention will be explained in detail below.

The toner constituting the two-component developer of the present invention includes a binder resin and other additives used as necessary.
By repeatedly applying mechanical energy by impact force in a gas phase to the resin particles obtained by kneading and pulverizing, the resin particles are sphericalized without substantially pulverizing them.

Here, "without substantially crushing resin particles" means
When the average particle size of the resin particle powder before being spheroidized is A, and the average particle size after spheroidizing is B, it means that the following conditions are satisfied.

Conditions: 0.93A≦B<A That is, in the above-mentioned spheroidization treatment, the resin particle powder is subjected to a mechanical energy of a magnitude that is not pulverized, for example, 175 to 171 of the mechanical energy normally required during pulverization.
Mechanical energy of approximately 0 magnitude may be applied. Specifically, it varies depending on the characteristics of the binder resin and cannot be defined unconditionally, but in the following example:
1.59 x 10- per particle of resin particle powder
3-9.56 X 110-5er, preferably 1.2
Mechanical energy of 0.times.10@-3 to 1.60.times.10@-'erg may be applied.

The circularity of the toner sphericalized by the spherical treatment is preferably 0.70 or more and 0.80 or less. When the circularity is too small, it becomes difficult to obtain sufficiently high fluidity, and on the other hand, when the circularity is too large, it becomes difficult to obtain sufficient leaning properties.

In the present invention, circularity is defined by the following formula.

Circularity - This circularity can be measured using, for example, an image analysis device (manufactured by Nippon Avionics).

The average particle size of the toner is preferably from 5 to 20 μm, particularly preferably from 8 to 15 μm. If the average particle size is too small, there is a risk that cleaning performance may be reduced or toner scattering may occur. On the other hand, when the average particle size is too large, it becomes difficult to form an image with high resolution.

Furthermore, in order to obtain a toner with uniform properties, it is preferable that the particle size distribution of the toner is narrow, and specifically, 90% by weight
The above toner particles are 0.5 to 1.5 of the average particle size of the toner.
Preferably, the range is twice that.

Here, the average particle size and particle size distribution of the toner were measured using a "Coulter Counter" (manufactured by Coulter Inc.), and the average particle size is defined as the average particle size when the cumulative weight reaches 50% by weight. particle size.

In addition, the toner has a static bulk density of 0.40-0.50.
g/cm". This static bulk density is used to evaluate the fluidity of the toner. Here, the static bulk density is, for example, 100 msec from the top of a container with a diameter of 28 mm and an internal volume of 100 mm. Loosely fill the toner through a sieve,
This is the value obtained by measuring the amount of toner at this time! Specifically, "Tasopdenser KY T-2000 type"
(manufactured by Seishin Enterprises).

The binder resin constituting the toner is not particularly limited, and conventionally known resins can be used. Examples of materials suitable for the heat fixing method include styrene resins, styrene-acrylic resins, styrene-butadiene resins, polyester resins, epoxy resins, polyamide resins,
Examples include polyurethane resin. In addition, suitable materials for the pressure fixing method include polyolefin necks such as polyethylene, polypropylene, and polytetrafluoroethylene; ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, and polyethylene-methacrylic acid ester copolymers. polyethylene copolymers such as; polyester; styrene-butadiene copolymers; waxes such as beeswax, carnauba wax, and microcrystalline wax;
Higher fatty acids such as stearic acid and palmitic acid, their salts, and their esters; Epoxy resin; Rubbers such as isobutylene rubber, cyclized rubber, and nitrile rubber; Polyamide; Chloron-indene resin; Maleic acid-modified phenolic resin; Phenol-modified Terpene resin: silicone resin; etc. can be mentioned.

The polyester resin preferably used as the binder resin of the toner is obtained by condensation polymerization of an alcohol monomer and a carboxylic acid monomer, and the alcohol monomers used include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1.2-propylene glycol, 1.3-propylene glycol, 1
．． 4-butanediol, neopentyl glycol, 1.
Diols such as 4-butynediol, 1.4-bis(hydroxymethyl)cyclohexane, and etherified bisphenols such as bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A1, polyoxypropylenated bisphenol A, etc. dihydric alcohol monomers. Examples of carboxylic acid monomers include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, cepatic acid, Examples include malonic acid, anhydrides of these acids, dimers of lower alkyl esters and lyluic acid, and other divalent organic acid monomers.

In addition to the above-mentioned divalent monomers, trivalent or higher valent monomers may be used if necessary.

Examples of trivalent or higher polyhydric alcohol monomers include sorbitol, 1,2.3.6-hexanetetrol, 1.
4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, L2
, 4-butanetriol, L2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2
-Methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3.5-
) lyhydroxymethylhenzene, and so on. In addition, examples of trivalent or higher polycarboxylic acid monomers include 1.2.4-benzenetricarboxylic acid, 1.
, 3.5-benzenetricarboxylic acid, 1,2.4-cyclohexanetricarboxylic acid, 2,5.7-naphthalenetricarboxylic acid, 1,2.4-naphthalenetricarboxylic acid, 1,2.4-butanetricarboxylic acid, L2 , 5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra(methylenecarpoxy)methane, 1,2,7.8-octanetetracarboxylic acid, Empol trimer acid , anhydrides of these acids, and others.

A styrene-acrylic resin preferably used as a binder resin for a toner is a resin obtained by copolymerizing a styrene monomer and an acrylic monomer. Specific examples of styrene monomers include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2.4
-dimethylstyrene, p-n-butylstyrene, p-
tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene ,p-
Examples include chlorstyrene, 3,4-dichlorostyrene, etc., and these monomers may be used alone,
A combination of a plurality of them may be used. Specific examples of acrylic monomers include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, n-butyl acrylate, propyl acrylate, and n-acrylate.
octyl, dodecyl acrylate, lauryl acrylate,
2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate,
Acrylic acid or its esters such as methyl α-chloroacrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, Methacrylic acid or its esters such as lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; and others, and these monomers They may be used alone or in combination.

In addition to the above-mentioned binder resin, additives that may be used as necessary to obtain the resin particle powder include, for example, a coloring agent, a charge control agent, a mold release agent, and the like.

Examples of colorants include carbon blank, nigrosine dye (C,1, NCL50415B), aniline blue (C,1, 50405), and calco oil blue (C,I).

Na azoic Blue 3), Chrome Yellow (C, 1, Il & 114090), Ultramarine Blue (C, 1, Il & 114090), DuPont Oil Red (
C,1,NlX26105>, quinoline yellow (
C, 1, 47005), methylene blue chloride (C, l It 52015), phthalocyanine blue (C, 1, 74160), malachite green off-salate (C, 1st floor 42000), lamp black (C, 1, 42000).

1, Floor 77266), Rose Bengal (C, 1, Floor 4)
5435), mixtures thereof, and others.

The content of the colorant is preferably 0.1 to 20 parts by weight, particularly preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the binder resin.

Various pigments or dyes can be used as the charge control agent. Specifically, nigrosine, azo, quaternary
Pigments or dyes such as ammonium salt-based and thiourea-based pigments can be used. These charge control agents may be used in combination. The content ratio of the charge control agent is preferably 0.1 to 10 parts by weight, particularly preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the binder resin.

Examples of mold release agents include polyolefins, fatty acid metal salts, fatty acid esters, partially saponified fatty acid esters, higher fatty acids, higher alcohols, liquid or solid paraffin waxes, amide waxes, polyhydric alcohol esters,
Silicone face, aliphatic fluorocarbon, etc. can be used. In particular, the softening point when measured by the ring and ball method specified in JIS K2531-1960 is 80 to 180°C.
In particular, polyolefins such as polyethylene and polypropylene having a molecular weight of 70 to 160'c are preferred. These mold release agents may be used in combination. The content of the release agent is preferably 1 to 10 parts by weight per 100 parts by weight of the binder resin.

The toner constituting the two-component developer of the present invention may be prepared by subjecting resin particle powder to spheroidization treatment and then further adding and mixing external additives such as a cleaning performance improving aid.

As the cleaning property improving aid, for example, fatty acid metal salts such as zinc stearate and calcium stearate, polymer particles such as polymethyl methacrylate particles, polystyrene particles, and polyvinylidene fluoride particles can be used.

The toner constituting the two-component developer of the present invention can be produced, for example, by the following method.

That is, the binder resin and other additives used as necessary are premixed, and then kneaded while melting using, for example, an extruder. Thereafter, it is cooled, and then coarsely ground using, for example, a hammer mill or a Willet type grinder, and further finely ground using, for example, a jet mill, and then classified to obtain resin particle powder with a desired particle size.

Next, by repeatedly applying mechanical energy by impact force to the resin particle powder in the gas phase using, for example, a surface treatment device that is an improved impact type crusher,
A toner is obtained by performing a spheroidization process without substantially pulverizing the resin particles.

FIG. 1 is an explanatory diagram showing an example of a surface treatment device that is an improved impact type crusher. In the figure, 11 is a raw material hopper, 12 is a stirring motor, 13 is a supersonic nozzle, 14 is a collision plate, 15 16 is a recycling collector, 16 is a collection cyclone, 17 is a raw material inlet, 18 is compressed air, 19 is an exhaust outlet, and 20 is a resin particle powder.

The spheroidization treatment of the resin particle powder may be performed at room temperature,
This may be done while heating to soften it slightly.

However, if the heating temperature is too high, the adhesiveness of the binder resin becomes high, and as a result, a phenomenon occurs in which the particles of the resin particles aggregate and form agglomerates, making it difficult to obtain a toner with a desired particle size distribution.

The carrier constituting the two-component developer of the present invention includes:
Without particular limitation, an uncoated carrier made of magnetic particles,
A resin-coated carrier in which the surface of magnetic particles is coated with a resin, a magnetic substance-dispersed carrier in which fine magnetic particles are dispersed in a binder resin, etc. can be used.

The magnetic material used for the carrier is a substance that is strongly magnetized in the direction of a magnetic field, such as iron, ferrite, magnetite, or other ferromagnetic metals such as iron, nickel, or cobalt, or alloys containing these metals. Compounds, alloys that do not contain ferromagnetic elements but become ferromagnetic by proper heat treatment, such as manganese-1 aluminum or manganese-1 aluminum
Examples include a type of alloy called Heusler alloy such as tin, chromium dioxide, and the like.

The resin that can be used to obtain a resin-coated carrier or a magnetic material-dispersed carrier is not particularly limited, and includes, for example, styrene resin, acrylic resin, styrene-acrylic resin, vinyl resin, ethylene resin, and rosin. Examples include resins such as modified resins, polyamide resins, and polyester resins. These resins are combined
It may also be used.

FIG. 2 is an explanatory diagram showing an example of a developing device that can be suitably used to perform development using the two-component developer of the present invention.

30 is a latent image carrier, and this latent image carrier 30 has a rotating drum-like form rotated in the direction of arrow X, and has a photosensitive layer 30B on a cylindrical conductive support 30A made of aluminum, for example. are constructed by stacking them.

On the upstream side of the developing space 44, a charger and an exposure optical system (
(not shown) is placed on the latent image carrier 3 using a charger.
The surface to be developed of 0 is charged to a constant potential, and then an optical image of the original is projected onto the surface to be developed of the latent image carrier 30 by an exposure optical system (not shown). A corresponding electrostatic latent image is formed, and the electrostatic latent image is moved to the development space 44, where the electrostatic latent image is developed.

31 is a developing sleeve, and this developing sleeve 31 is
The developing sleeve 31 has a rotating drum shape made of a non-magnetic material such as aluminum, and a magnet roll 32 is disposed inside the developing sleeve 31 .

This magnet roll 32 consists of a plurality of N and S magnetic poles arranged along the circumference of the developing sleeve 31.

The developing sleeve 11 and the magnetic roll 32 constitute a developer carrier, and in a specific example, the developing sleeve 31 moves in the direction of arrow Y, that is, in the developing space 44 in the same direction as the moving direction of the latent image carrier 30. The magnet roll 32 is rotated, for example, in the direction of arrow Z, that is, in the opposite direction to the developing sleeve 31. In the present invention, the rotation directions of the developing sleeve 31 and the magnet roll 32 are not particularly limited, and they may be rotated in appropriate directions.

In addition, the developing sleeve 31 is fixed and the magnet roll 3
2 may be rotated, or the magnet roll 32 may be fixed and the developing sleeve 31 may be rotated. Further, the moving speed of the developer layer 43 is preferably about the same as or higher than the moving speed (circumferential speed) of the latent image carrier 30, but is not limited thereto.

The magnetic flux density of the N and S magnetic poles constituting the magnet roll 32 on the surface of the developing sleeve 31 is usually 500 to 15
The developing sleeve 31 is magnetized to have a magnetic force of approximately 0.00 Gauss, and a developer layer 43 is formed on the surface of the developing sleeve 31 by the magnetic force, in which developer particles 420 made of toner and carrier are erected in a brush-like manner.

Reference numeral 33 denotes a regulating blade, which is made of a magnetic or non-magnetic material and is used to regulate the height and amount of the developer layer 43 reaching the developing space 24. 34 is a scraper, and this scraper 34 is for scraping the developer remaining on the surface of the developing sleeve 31 after development. The surface of the developing sleeve 31 scraped by the scraper 34 comes into contact with the developer 42 again in the developer reservoir 35, and a new developer layer 43 is formed on the developing sleeve 31 in the same manner as above, and this is transported to the developing space 44. be done.

35 is a developer reservoir, and 36 is an agitation screw. In the developer reservoir 35, the agitation screw 36 mixes and agitates the toner and carrier constituting the developer 42, thereby efficiently imparting a triboelectric charge to the toner. Ru. Further, among the developer 42, the carrier is used repeatedly, whereas the toner is consumed every time development is performed.
New toner from the pumper 37 is appropriately replenished into the developer reservoir 35 by a supply roller 38 having a recessed portion on its surface.

39 is a bias power supply, 40 is a protection resistor, and a bias voltage is applied to the developing space 44 by the bias power supply 39. The bias power supply 39 can have a variety of configurations, such as a configuration that generates only a DC voltage, a configuration that generates only an AC voltage, and a configuration that generates a voltage in which a DC voltage is superimposed on an AC voltage. .

[Specific examples]

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to these examples.

(Production of toner) (1) Toner TI Styrene-acrylic copolymer (monomer composition: styrene: methyl methacrylate: butyl acrylate = 75
: 10 : 15. Glass transition point Tg = 59°C) 1
00 parts by weight and carbon black (Mogul L.

10 parts by weight (manufactured by Capot) and a charge control agent (dye).

After premixing 2 parts by weight of Subiron Brasok TRH (manufactured by Hodogaya Chemical Co., Ltd.) using a Henschel mixer, the mixture was melt-kneaded using an extruder at a temperature of 120°C, then cooled, coarsely pulverized, finely pulverized using a jet mill, and further The resin particles powder (1) having an average particle size of 11.0 μm was obtained by classification. In this resin particle powder +11,
The proportion of particles of 5μ or less was 0.3% by weight, and the proportion of particles of 20μ or more was 0.9% by weight.

Next, using a surface treatment device that is an improved version of an impact crusher,
In a gas phase, while heating to a temperature of 40° C., mechanical energy mainly consisting of impact force was repeatedly applied to the resin particle powder (1) for 5 minutes to perform a spheroidization treatment to obtain toner TI. Ta.

This toner TI has an average particle size of 10.9u, a proportion of particles of 5 p* or less, 0.7% by weight, a proportion of particles of 20 μm or more, 0.2% by weight, and a yield based on resin particle powder (1). 88%, circularity 0.74, static bulk density 0.41g/c
It was m3.

(2) Toner T2 In the production of toner T1, a styrene-acrylic copolymer (monomer composition: styrene:butyl methacrylate-75:25.
The same procedure was used except that the glass transition point Tg = 61°C) was used, and the melt-kneading temperature was 125°C, and the average particle size was 10.3°C.
Resin particle powder (2) of x was obtained. This resin particle powder (2
), the proportion of particles of 5μ or less is 1.0% by weight, 2
The proportion of particles with a size of 0μ1 or more was 0.4% by weight.

Next, using a surface treatment device that is an improved version of an impact crusher,
In the gas phase, without heating, the resin particle powder (2)
A spheroidization process was performed by repeatedly applying mechanical energy mainly consisting of impact force for 5 minutes to obtain toner T2.

This toner T2 has an average particle size of lo, In, 51 μm.
The proportion of the following particles is 1.8% by weight, the proportion of particles with 2 On or more is 0.1% by weight, the yield with respect to resin particle powder (2) is 86%, the circularity is 0.72, and the static bulk density is 0. .40 g
/cm'.

(3) Toner T3 Toner T3 was manufactured in the same manner as Toner T1 except that the resin particle powder (1) was used and the spheroidization treatment conditions were changed.
I got 3.

This toner T3 has an average particle size of 10.9μ, a proportion of particles of 5n or less of 0.5% by weight, a proportion of particles of 20μ or more of 0.5% by weight, and a yield of 89% based on resin particle powder (1).
%, circularity 0.70, static bulk density 0.39g/cm3
Met.

(4) Toner T4 Toner T4 was manufactured in the same manner as Toner TI, except that the spheroidization treatment conditions were changed using resin particle powder fl).
I got 4.

This toner T4 has an average particle size of 10.8 μm, a proportion of particles of 5 μm or less in a proportion of 0.9% by weight, a proportion of particles of 20I# or more in a proportion of 0.1% by weight, and a yield based on resin particle powder (1). is 86%, circularity is 0.80, static bulk density is 0.42g/
It was cm3.

(5) Comparative toners t1 to t4 Each of the above toners T1 to T4 has hydrophobic silica fine particles (R-812, manufactured by Nippon Aerosil Co., Ltd.) as a fluidizing agent.
were externally added and mixed at a ratio of 0.8% by weight to obtain comparative toners t1 to t4.

(6) Toner for comparison t5. t6 Resin particle powder fil and (2) obtained in the production of toners TI and T2, respectively, are referred to as comparative toners t5 and t6.

(7) Comparative Toner t7 Resin particle powder (11
was passed through a hot air stream at 340° C. using a spray drying device to perform a spheronization treatment to obtain a coarse toner powder. This toner coarse powder has an average particle size of 13.5 pm.
, the proportion of particles of 5n or less is 0.1% by weight, the proportion of particles of 20x or more is 3.8% by weight, the yield with respect to resin particle powder (1) is 73%, the circularity is 0.81, the static bulk density is 0.4
It was 2g/cm'.

As mentioned above, this toner coarse powder has a large proportion of large-diameter particles, so it is difficult to put it to practical use as it is, and further classification is required. Therefore, the above toner coarse powder was further classified and the average particle size was 11.1.
A comparison toner t7 of μ-color was obtained. As a result, the yield was 53%
and decreased considerably.

(Production of carrier) (1) Carrier CI 150 g of styrene-methyl methacrylate copolymer (monomer composition ratio - 4:6) was added to 300 g of methyl ethyl ketone (h
! Prepare a coating solution by dissolving it in "Spira Coater" (
The above coating liquid was applied to 5 kg of ferrite powder having an average particle size of 1100p using a ferrite powder (manufactured by Kaida Seiko Co., Ltd.), and then heated and dried to obtain a resin-coated carrier. This is referred to as [Carrier CIJ].

(2) Carrier C2 In the production of carrier C1, styrene-
Methyl methacrylate copolymer monomer composition ratio -3 = 7
) A resin-coated carrier was obtained in the same manner as above except for the following changes. This is referred to as [Carrier C2J.

(Preparation of two-component developer) With the combinations shown in Table 1 below, the toner concentration is 3.5% by weight.
Each two-component developer was prepared by mixing the carrier and toner so that the following was obtained.

(Evaluation of triboelectricity of toner) Using each of the two-component developers described above, the amount of triboelectricity of the toner was measured by a known blow-off method under various environmental conditions. The results are shown in Table 2 below.

Table 2 (actual copying test) Using each of the above two-component developers, an electrophotographic copying machine R U-Bix1600 was tested under various environmental conditions.
J (manufactured by Konishi Roku Photo Industry Co., Ltd.), a photocopy test was conducted to form a copy image, and the following items were evaluated. The results are shown in Table 3 below.

(2) Amount of toner adhesion The amount of non-magnetic toner (mg) per unit area (cm2) adhering to the electrostatic latent image during development was measured and evaluated.

Note that the copy original used was solid black.

(2) Cleaning property After repeatedly forming a copy image, the surface of the latent image bearing member immediately after undergoing the cleaning process was visually observed, and judgment was made based on the presence or absence of deposits on the surface of the latent image bearing member. The evaluation is "○" if there is almost no deposits observed and the product is in good condition, "△" if some deposits are observed but at a practical level, and "△" if a lot of deposits are observed and there is a problem in practical use. was set as 1×.

The 0-quality copied images were visually judged in terms of image unevenness, black spots, fogging, and strawberry scratches. The evaluation is "O" if it is good, and "△" if it is slightly poor but at a practical level.
”, and cases where it is defective and has a practical problem are marked as “×”.

"Image unevenness" refers to the phenomenon in which differences in shading occur across the entire image, "black spots" refers to the phenomenon in which spot-like stains occur, and "strawberry scratches" refers to the phenomenon in which strawberry-shaped stains occur. represents.

(2) Fixability The fixability was determined by rubbing the copied image with a cotton cloth or the like. The evaluation was ``○'' if it was good, ``△'' if it was slightly poor but at a practical level, and ``x'' if it was poor and had a practical problem.

As can be understood from the results of the above examples, the two-component developer of the present invention has high toner fluidity, a large amount of toner adhesion, and low environmental dependence of toner triboelectrification. It is small and exhibits excellent developability even under high-temperature conditions, and also provides good leanability. Therefore, it is possible to stably form a good image with high image density and without image unevenness, black spots, fog, or strawberry scratches.

On the other hand, according to the comparative toners t1 to t4, since a fluidizing agent was added and mixed, the triboelectric charging properties of the toners were highly dependent on the environment, and under high-temperature conditions, the image Image unevenness and fogging occur, and under low temperature and low humidity conditions, image unevenness and strawberry scratches occur.

According to the comparative toners t5 and t6, since neither of them was subjected to spheroidization treatment, the developability was poor.

According to the comparative toner t7, the degree of sphericity is quite high, so the developability is good, but the cleanability is poor.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a surface treatment device that is an improved impact crusher that can be suitably used to obtain the toner constituting the two-component developer of the present invention, and FIG. FIG. 2 is an explanatory diagram showing an example of an electrostatic image developing device that can be suitably used to perform a developing process using a two-component developer. 11... Raw material pumper 12... Stirring motor 13... Ultrasonic nozzle 14... Collision plate 15.
... Recycling collector 16 ... Collection cyclone 17 ... Raw material inlet 18
...Compressed air population 19...Exhaust outlet 20...
・Resin particle powder 30...Latent image carrier 30A...
- Conductive support 30B... Photosensitive layer 31... Developing sleeve 32... Magnet roll 33...
Regulatory Blade 39... Bias Power Supply Procedure Amendment (Voluntary) June 24, 1988 Director General of the Patent Office Yoshi 1) Moon Takeshi 1, Indication of Case Patent Application No. 62-68002 2, Title of Invention Two-Component System Relationship with the developer 3° correction case Patent applicant address 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Name
(127) Konica Co., Ltd. 4, Agent 5, Subject of amendment (1) Column 6 of detailed explanation of the invention in the specification, Contents of amendment (1) ■ Lines 10 and 11 of page 22 of the specification Insert the following between. “The device in this example is a batch type device that repeatedly applies mechanical energy to the resin particle powder 20, and during the surface treatment of the resin particle powder 20, the resin is transferred from the recycling collector 15 to the collecting cyclone 16. Transfer of the particle powder 20 is prohibited, and after the surface treatment, all the resin particle powder 20 can be transferred from the recycling collector 15 to the collection cyclone 16. In addition, the resin particle powder 20 is substantially In order to prevent pulverization, the pressure of the compressed air 18 can be adjusted to control the impact force applied to the resin particle powder 20.'' ■ Lines 11 and 12 of page 27 of the specification Insert the following in between. [Figure 3 is an explanatory diagram showing another example of the surface treatment device. In the figure, 6N is a powder input valve, 62 is a powder input chute, 63 is a circulation circuit, 64 is a casing, and 65 is a rotation 66 is a blade, 67 is a stator, 68 is a jacket for cooling or heating, 69 is a powder discharge chute,
70 is a powder discharge valve. Note that the arrow represents the locus of the powder. When the rotary disk 65 having the blades 66 is rotated at high speed,
The centrifugal force acts on the internal air by the blades 66, so that the outside of the rotary disk 65 is pressurized, and the center of the rotary disk 65 is under negative pressure. Since the outside and center of the rotary disk 65 are connected by the circulation circuit 63, the pressurized air outside the rotary disk 65 moves to the center of the rotary disk 65 through the circulation circuit 63. A circulating flow of air is formed. In a state where such a circulating air flow is formed, when resin particle powder is introduced from the powder input chute 62 provided in the middle of the circulation circuit 63, the introduced resin particle powder flows into the circulation circuit together with this circulation flow. During this circulation process, the resin particles collide with the blade 66 and receive an impact force, thereby making the resin particles spherical. After performing this circulation process for a certain period of time, the powder discharge valve 70 is opened to discharge the treated resin particle powder by centrifugal force, thereby obtaining spherical resin particle powder. In such a circulation process, the circulation circuit 63 and the powder official chute 69 may be cooled or heated by a jacket 68 provided on the stator 67 side in order to control the temperature inside the apparatus. (2) ■ Lines 8 to 9 of page 41 of the specification are corrected as follows. "An explanatory diagram showing an example of an electrostatic image developing device that can perform the following. Figure 3 is an explanatory diagram showing another example of a surface treatment device." ■Add the following after line 19 on page 41 of the specification. . 61... Powder input valve 62... Powder input sinito 63... Circulation circuit 64... Casing 65... Rotating plate 66... Blade 67.
...Stator 68...Jacket 69...
Powder discharge chute 70...powder discharge valve" (3) Figure 3 of the drawings is added as shown in the attached sheet.

Claims (1)

[Scope of Claims] 1) A two-component developer consisting of a toner and a carrier to which no fluidizing agent is added, wherein the toner contains a binder resin and other additives used as necessary. The resin particles are sphericalized by repeatedly applying mechanical energy by impact force in the gas phase to the resin particles obtained by kneading and pulverizing, without substantially pulverizing the resin particles. A two-component developer. 2) The two-component developer according to claim 1, wherein the non-magnetic toner has a circularity of 0.70 or more and 0.80 or less.