JP3146572B2 - Electrostatic latent image developing toner and electrostatic latent image developing method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic latent image used in an electrophotographic copying machine and a printer. More specifically, the toner of the present invention has a specific surface property and is used in a method of forming a uniform thin charged toner layer to develop an electrostatic latent image.

[0002]

2. Description of the Related Art In recent years, high image quality and high reliability have been demanded in electrophotographic copying machines and printers, and with this, various performances have been demanded in toner and developing methods. It became so.

In response to such demands, a method has been proposed in which toner is supplied to the surface of a toner carrier, and a regulating member is pressed against the surface to form a thin charged toner layer on the outer peripheral surface of the carrier. In this developing method, the toner is pressed by the regulating member and charged. In this case, it is particularly important that the toner regulation amount and the toner charge amount are constantly maintained. For that purpose, it is desirable that the surface of the toner carrier and the surface of the regulating member are always in the same state.

[0004] However, the conventional toner surface has many irregularities and pores, and cracks or chips therefrom when pressed by a regulating member to generate fine powder, or a fluidizing agent such as silica used as a post-treatment agent. Is embedded in the recesses and pores on the surface of the toner, thereby lowering the fluidity of the toner. As a result, filming of the toner carrier, fusion of the toner to the regulating member, and fixation occur. For example, when the toner is fused or adhered to the blade surface, the shape of the entrance of the regulating portion changes, so that the amount of charge of the toner, the amount of adhesion to the carrier, and the like change. In addition, when the surface of the toner carrier undergoes a change such as filming, the charge applying force to the toner changes, and the charge amount of the toner also changes. As described above, the change in the amount of toner attached and the amount of charge causes the toner to be blurred, fogged, scattered, and the like, leading to contamination of the apparatus and deterioration of image quality.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. That is, the present invention relates to a toner used in a method of supplying a toner onto the surface of a toner carrier and developing an electrostatic latent image using a thin toner layer triboelectrically charged on the carrier by a regulating member. An object of the present invention is to provide a toner which does not generate fine powder, fix toner on the surface of a toner carrier and a toner regulating member, and does not cause filming.

[0006]

That is, according to the present invention, the surface texture has the following conditional expression [I]: 1 ≧ D / d ₅₀ ≧ 0.5, where D = 6 / (ρ · S) [I] [expression] in, D is representative of the conversion grain size from the specific surface area when it is assumed the shape of the toner and the spherical (μm); d ₅₀ represents a 50% equivalent particle diameter of the particle径別relative weight distribution of the toner ([mu] m), d ₅₀ is 6μ
m and 11 μm or less; ρ represents the density (g / cm ³ ) of the toner; S represents the BET specific surface area (m ² / g) of the toner, respectively. For toner.

The surface properties of the toner of the present invention are determined by the conditional expression [I].
That is, D / d50 ≧ 0.5, preferably D / d50 ≧ 0.5.
55, and more preferably D / d50 ≧ 0.6. Supplying such a toner of the present invention on the surface of a toner carrier,
By applying to a method of developing an electrostatic latent image using a method of forming a thin toner layer by frictionally charging the carrier with a regulating member, generation of toner fine powder, toner carrier, toner regulating member Adhesion of the toner on the surface, filming, and the like can be prevented.

In conditional formula [I], D is a converted particle size (μm) from the BET specific surface area when the shape of the toner is assumed to be spherical.
, D50 represents a true density (g / cm ³ ), and d50 represents a 50% equivalent particle size (μm) of the relative weight distribution by particle size.
Represents a BET specific surface area (m ² / g). The D / d50 becomes closer to 1 as the toner surface becomes smoother. D /
When d50 is smaller than 0.5, the toner has many irregularities,
Since the toner has pores, the toner breaks around the recesses and / or the pores when the toner passes through the pressure contact portion by the regulating member, and silica, which is a fluidizing agent added to the recesses as an external additive, is used. Inconveniences such as the embedding of the particles and the shaving of the projections to generate fine powder occur. As a result, the fluidity of the toner deteriorates, and filming and fixing to the toner carrier and the toner regulating member are promoted.

As the toner that can be used in the present invention, any conventionally used toner can be used. For example, an aqueous suspension polymerization method, a suspension granulation method, and a non-aqueous solvent system can be used. Those prepared by a non-aqueous dispersion polymerization method, a melt-kneading pulverization method, or the like can be used.

In order to obtain a toner having a surface property satisfying the conditional expression [I] from such a toner, for example, treatment such as heating of a fluidized bed and relaxation in a swelling solvent may be performed. As this treatment method, any known method can be suitably used,
For example, in the heat treatment, a surface modification device as shown in FIG. 1 may be used. This is a method for modifying the toner surface by a pressurized hot air flow.

This surface reforming apparatus will be specifically described with reference to FIG. As shown in FIG. 1, hot air generator
The high-temperature and high-pressure air adjusted in (1) is injected from the hot-air injection nozzle (6) through the introduction pipe (14). On the other hand, the toner particles are conveyed by a predetermined amount of pressurized air from the fixed amount supply device (4) through the introduction pipe (2), and a plurality of sample injection nozzles (7) provided around the hot air injection nozzle (6). It is injected into the hot air stream. At this time, each of the sample injection nozzles (7) is jetted toward the center of the hot air stream, and the toner particles collide with each other with an appropriate force in the hot air stream, thereby increasing the dispersibility of the particles in the hot air stream. Is preferable in that the heat treatment is performed uniformly for each toner particle. The toner particles ejected in this way are instantaneously brought into contact with high-temperature hot air and uniformly heated. The temperature of the hot air is + 100 ° C. or more of the glass transition temperature of the thermoplastic resin on the surface of the toner particles.
It is preferable that the temperature is 500 ° C. or lower. The term “instantaneous” herein refers to the time during which the desired modification of the toner particles (heat treatment) is achieved and the aggregation of the toner particles does not occur, depending on the processing temperature and the concentration of the sample in the hot air flow. , Usually less than 2 seconds. Next, the toner particles that have been subjected to the instantaneous heat treatment are rapidly cooled to a temperature equal to or lower than the glass transition temperature of the thermoplastic resin of the toner particles by the cold air introduced from the cooling air introduction part (8) immediately. Such rapid cooling eliminates adhesion to the device walls and aggregation of particles, and improves the yield. Thereafter, the toner particles are passed through the introduction pipe (15) and into the cyclone.
Collected by (9). The cyclone (9) is also provided with a cooling jacket to keep the toner particles in the cyclone portion in the above-mentioned temperature range by flowing cooling water, thereby preventing toner particles from aggregating.

The flow velocity of the pressurized hot air flow and the toner blowing speed in the present apparatus depend on the temperature of the pressurized hot air flow, the particle size of the toner, the particle size distribution, the specific gravity, the thermal characteristics of the thermoplastic resin used, and the like. What is necessary is just to select suitably. Further, cooling after the heat treatment of the toner particles is essential. If it is not intentionally cooled after the heat treatment, the residual heat during the heat treatment and the heat generated when spinning in the cyclone that collects the toner particles cause the temperature of the toner surface to exceed the glass transition temperature of the thermoplastic resin. As a result, the toner particles are thermally aggregated with each other and cannot withstand actual use.

With respect to the toner thus obtained, a fluidizing agent (fine particle silica, fine particle titanium oxide, fine particle alumina, etc.), a cleaning agent (vinyl resin particles such as vinylidene fluoride, styrene, acrylic, Teflon, etc.), zinc stearate And post-treatment with metal soap such as.

The toner of the present invention is suitably used in a developing method including means for forming a thin toner layer on the surface of a toner carrier by frictionally charging the toner with a toner regulating member. A specific apparatus for carrying out such a developing method will be described below with reference to the drawings.

FIG. 2 shows a developing section of a copying machine provided with a two-component developing device (51). The developing device (51) is a photoconductor (100)
The surface of the photoreceptor (100) is charged, toner is supplied to an electrostatic latent image formed by exposure, and this is visualized. The developing device (51) generally includes a casing (53) and a cover (53a).
A developing sleeve (54) and a toner supply roller (toner carrier) (32) are sequentially arranged rightward from the photoconductor (100) side in a developing tank (52) composed of Behind (32), a toner storage tank (42) is formed.

The developing sleeve (54) is made of a conductive non-magnetic material,
For example, a cylindrical body made of aluminum, on the surface of which a minute concave portion is formed by blasting, facing a photoconductor (100) rotated and driven in the direction of arrow (a) with a developing gap (Ds), It can be driven to rotate in the rotation direction [direction of arrow (b)].

A DC developing bias power supply 25 (developing bias voltage: Vb) is provided between the developing sleeve 54 and the ground.
In the drawing, the negative side of the developing bias power supply (25) is connected to the developing sleeve (54), and a negative charge is stored on the surface of the developing sleeve (54).
The magnet body (2) housed inside the developing sleeve (54)
6), a plurality of magnets having magnetic poles extending in the axial direction are arranged so that the magnetic poles are alternately located on the outer periphery in the S-pole and the N-pole, and are fixed in a state shown in FIG.

Above the photoconductor (100) side of the developing sleeve (54), a main developer stirring plate (2) attached to a cover (53a) is provided.
7) oppose each other with a hot height regulation gap (Db). A cover (5) is provided obliquely above the right side of the developing sleeve (54).
3a) The auxiliary developer stirring plate (2) attached to the support (28)
9) are opposed to each other, and together with the main developer stirring plate (27), form an empty space (31) above the developing sleeve (54). The auxiliary developer stirring plate (29) has a slit (30) formed in the axial direction of the developing sleeve (54).

The toner supply roller (32) is formed of a conductive non-magnetic material such as aluminum, and has a minute concave portion formed on the surface thereof. The toner supply roller (32) is parallel with the supply gap (Dss) on the back side of the developing sleeve (54). And can be driven to rotate in the direction of arrow (c). Also, this toner supply roller
(32) is grounded via an AC power supply (33) and a DC power supply (34). As a result, a pulsating recovery bias voltage in which AC is superimposed on DC is applied to the toner supply roller (32). Have been.

Above the rear side of the toner supply roller (32), a partition wall (35) is attached so as to be rotatable about a support shaft (36). The other end of the pressure contact spring (37) having one end attached to the end is locked, and the partition (35) is constantly urged in the direction of the arrow (e). As a result, the metal blade (toner regulating member) (38) attached to the lower part of the partition (35) is in light pressure contact. The metal blade (38) and the auxiliary developer stirring plate (29) are connected by a sheet (39), and by these, an empty space (40) is provided above the toner supply roller (32).
Are formed. Below the toner supply roller (32), a toner return prevention film (41) attached to a casing (53) is pressed against the toner supply roller (32) in the rotation direction.

The toner container (42) is provided with the partition (35),
The rear portion of the developing tank (53) is partitioned by a metal blade (38), a toner supply roller (32), and a toner return preventing film (41). 43) is mounted so as to be rotatable in the direction of arrow (d).

In the developing device having the above configuration,
First, the developing sleeve (54) and the toner supply roller (3)
2) A starter made of a mixture of a negatively-charged magnetic carrier and a positively-charged insulating toner is loaded in the upper empty space (31), and the insulating toner is loaded in the toner storage tank (42). At this time, only the magnetic carrier may be loaded in the empty space (31) instead of the starter. When a print switch (not shown) is turned on while the carrier and the toner are filled, the developing sleeve (54), the toner supply roller (32), and the stirring bar (43) are moved in the directions of arrows (b), (c), and (c), respectively.
Rotate in the direction (d).

By operating the developing device (51) as described above, the toner is supplied to the toner supply roller at the bottom of the toner storage tank (42) by the stirring action of the stirring rod (43).
The toner flows toward (32), is taken into the minute concave portions on the surface of the toner supply roller (32), and is filled. Toner supply roller
The toner supplied to (32) is conveyed in the direction of arrow (c), and excess toner is scraped off by the metal blade (38), and is also pre-charged by the contact thereof, so as to be opposed to the developing sleeve (54). It reaches the [toner supply area (Y)]. In the toner supply area (Y), the developing sleeve (54)
While the toner is supplied to the developer held thereon,
Excess toner on the developing sleeve (54) is
Collected at (32). The operation of supplying and collecting the toner will be described later in detail.

The toner supplied to the developing sleeve (54) is transported along with the carrier held on the peripheral surface of the developing sleeve (54) in the direction of the arrow (b) based on the rotation thereof, and the auxiliary developer is stirred. Most of the developer is blocked by the plate (29). Then, the developer is pushed by the developer that is conveyed later, warps up along the auxiliary developer stirring plate (29), passes through the slit (30), and is vacant on the downstream side (3).
It is sent to 1). The remaining developer is the auxiliary developer stirring plate (2
It passes through the gap between 9) and the developing sleeve 54 and reaches the vacant space 31 on the downstream side. The developer that has reached the vacant room (31)
The developer is blocked by the main developer agitating plate (27), and rises while rotating counterclockwise in the vacant space (31) along the main developer agitating plate (27). It is mixed with the agent.

In this way, a part of the mixed and stirred developer passes through the spike height regulating gap (Db) between the main developer stirring plate (27) and the developing sleeve (54) to form a magnetic brush. The magnetic brush is applied to the photoconductor (10) in the development area (X).
The surface of 0) is rubbed, and the electrostatic latent image on the surface is developed and visualized.

The charging of the toner is mainly performed in the toner supply area (Y).
After that, it is applied to the vacant chambers (40) and (31) by a triboelectric charging with the carrier during a short time from the beginning to the developing area. After passing through the developing area (X), the developer remaining on the peripheral surface of the developing sleeve (54) is continuously transported in the direction of the arrow (b) based on the rotation of the developing sleeve (54), and the toner supply roller
When reaching the toner supply area (Y), which is a part opposed to (32),
The operation of supplying and collecting the toner is performed between the developing sleeve (54) and the toner supply roller (32). Then, the toner supplied to the developing sleeve (54) returns to the empty chambers (40) and (3).
When 1) is reached, the developer sufficiently mixed and stirred here is uniformly replenished on the surface of the developing sleeve 54, and the consumption pattern of the toner consumed in the previous development is erased.

On the other hand, the toner collected by the toner supply roller (32) enters the minute concave portion, passes between the toner return prevention film (41) and the toner storage tank (52).
The toner is replenished to the minute concave portions again.

The operation of supplying and recovering toner in the toner supply area (Y) will be described below. In the toner supply area (Y), a magnet body is formed on the developing sleeve (54).
Along the magnetic field formed in the radial direction from the magnetic pole (N) of (26), the developers are connected in a daisy chain to form a magnetic brush. On the other hand, the minute concave portions on the surface of the toner supply roller (32) are filled with pre-charged toner. The toner supply roller (32) has a DC power supply (34) and an AC power supply (33).
Since the bias voltage (Vss + Vrms) superimposed on the charged toner is applied, the charged toner is applied to the toner supply roller (32) according to the periodic change of the AC voltage (Vrms) toward the developing sleeve (54) on the surface. Vibrating. For this reason, the toner frequently contacts the magnetic brush, and the toner is efficiently scraped off by the magnetic brush.

The applied AC voltage (Vrms) can be effectively implemented when the voltage value is 300 V or more and the frequency is in the frequency band of 20 Hz to 2 kHz. The AC power supply may be a so-called sine-wave AC power supply or a non-sinusoidal AC power supply such as a pulse wave or a triangular wave.

On the other hand, on the developing sleeve (54), the excess toner which is in contact with the carrier and is charged to a positive polarity is caused by the difference between the bias voltage applied to the developing sleeve (54) and the toner supply roller (32). Based on the toner supply roller
(32) is electrically sucked, and the suction force acting on the toner is also periodically changed under the influence of the AC power supply (33). Therefore, the excess toner is easily peeled off due to the electrostatic attraction with the carrier. The excess toner is transferred to the toner supply roller (32).
To be collected efficiently.

As described above, between the developing sleeve (54) and the toner supply roller (32), the amount of toner supply and the amount of recovery is drastically increased, and the fluctuation range of the toner is reduced. (X) The amount of toner conveyed is stable, and a copy image without density unevenness can be obtained. Then, the toner collected by the toner supply roller (32) enters the minute concave portion, passes between the toner return preventing film (41), and reaches the toner storage tank (42). Is done.

FIG. 3 shows another specific example of the two-component developing device. The two-component developing device (61) includes a photosensitive drum (100) and a casing (6) that are driven to rotate in the direction of arrow (a).
4). At the front of the casing (64), a developing sleeve (6) facing the photosensitive drum (100) is provided.
6) is accommodated. The developing sleeve (66) is a cylindrical body made of a non-magnetic conductive material, to which a developing bias (Vb) is applied, and is rotatable in a direction indicated by an arrow by a driving source (not shown).

A magnetic roller (67) is fixed inside the developing sleeve (66). A plurality of magnets having magnetic poles extending in the axial direction are provided on the magnetic roller (67) on the outer peripheral portion thereof. The stations are arranged alternately. Developing sleeve (6
A spike height regulating member (68) is provided obliquely below the rear of (6), and its front end faces the outer peripheral surface of the developing sleeve (66) with a predetermined spike height regulating gap, and the upstream end of the developing sleeve in the rotation direction of the developing sleeve has a developing end. An agent pool is formed.

A toner supply roller (toner carrier) (70) is provided behind the developing sleeve (66).
6) and a predetermined supply gap. The toner supply roller (70) is made of a non-magnetic conductive material similarly to the developing sleeve (66). A minute concave portion is formed on the outer peripheral portion by blasting, etching, or the like. It can be driven to rotate. Further, the minus side of the direct current (Vss) on which the blast side is installed is applied as a recovery bias (Vs) to the toner supply roller (70) via an alternating current (Vrms). In particular, the output of the direct current (Vss) is It is variable.

Further, the tip of a toner regulating blade (toner regulating member) (71) attached to the casing (64) is pressed against the outer peripheral surface of the upper portion of the toner supply roller (70). Toner supply roller (70), regulating blade (71)
A toner hopper is formed at a rear portion of the casing (64) partitioned by, and transport blades (76) and (78) are rotatably arranged. The developing device (6
1) a toner in a toner hopper and a developing sleeve (66)
In addition, a starter in which a toner and a carrier are mixed at a fixed ratio is loaded in the developer reservoir. Note that only the carrier may be loaded instead of the starter.

FIG. 4 shows a specific example of a one-component developing device. The one-component developing device (81) is arranged adjacent to the photosensitive drum (100) that is driven to rotate in the direction of the arrow (a). The developing device (81) includes a developing roller (90) serving as a rotating body, a cylindrical thin-film member (toner carrier) (91) having a slightly longer circumference, which is provided on the developing roller, and two ends of the thin-film member. This is pressed against the developing roller (90) and a space is formed between the developing roller and the developing roller.
An elastic pad (89) forming (s), a pressure contact blade (toner regulating member) (9) pressed against the outer surface of the thin film member
2) and a casing (83) for supporting and storing these and storing the toner (To).

First, a thin film member (91) as a toner carrier
Is formed of a conductive member such as a nickel electroformed film.
A DC or / and AC developing bias voltage is applied to the toner thin film member (91). The shape of the developing roller is not particularly limited as long as it is not practically limited.
For example, it may be a belt shape. As the material, structure, and contact pressure of the press contact blade (92), any of those known in a conventional developing device using a one-component developer can be suitably used. Further, a toner leveling pad (96) is provided downstream of the developing area (X). The casing (83) is provided with a toner storage tank (95). The toner storage tank (9
5) is provided with an agitator (94) which rotates in the direction of the arrow (c), and moves in the direction of the arrow (c) while preventing blocking of the toner (To) stored inside.

Next, the operation in the case of performing development using the apparatus of the present invention will be described with reference to FIG. Developing roller
(90) and the agitator (94) are rotated in the directions of arrows (b) and (c) by a driving source (not shown), respectively.
(To) is forcibly moved in the direction of arrow (c). The toner (To) in the toner storage tank (95) adheres to the surface of the developing roller (90) by contact with the developing roller (90) and electrostatic force, and is transported in the direction of the arrow (b). The toner (To) is taken into a wedge-shaped portion formed by the developing roller (90) and the tip of the blade (92), reaches the pressure contact portion of the blade (92), and is a thin film member as a toner carrier. It is uniformly applied in a thin layer on the surface of (91) and is triboelectrically charged to a predetermined positive or negative polarity.

The pressing blade (92) has, at its tip, a material of a triboelectric series suitable for charging the toner to a desired polarity, and presses the surface of the developing roller (90). At this time, if there are many irregularities and pores on the toner surface, the toner is cracked or chipped by the pressure contact of the regulating member, or an external additive is embedded in the toner surface. As a result, the fluidity of the toner deteriorates, fine powder is generated, and the toner is aggregated in the vicinity of the blade pressing surface, and the toner is fused and fixed to the blade pressing surface.
A phenomenon such as filming of the toner on the toner carrier occurs. As a result, the regulation condition of the toner changes, and the uniformity of the toner adhesion and the charge amount of the charged toner layer of the toner carrier after passing through the regulation member pressing surface is impaired. In particular, it becomes remarkable when performing repeated copying, causing deterioration in image quality such as so-called uneven streaks and fogging on the image surface,
It may cause toner spill, scattering, and powder smoke.

On the other hand, when the toner having the surface property satisfying the conditional expression [I] of the present invention is used, the slip property between the toner and the slip property with the blade is good, and the above-mentioned property due to the pressure contact of the regulating member is obtained. Little change in toner shape. For this reason, the toner immediately passes through the pressure contact surface in order,
A uniform thin layer of charged toner is formed on the toner carrier for a long time, and stable high image quality and high reliability are obtained.

The thin-layer toner (To), which is held on the thin-film member (91) by electrostatic force due to its own charge, moves further and moves to a portion (developing area (X)) facing the photosensitive drum (100). Conveyed, surface potential of photosensitive drum (100) and thin film member
An electric field based on the voltage difference from the bias voltage applied to (91) moves to the electrostatic latent image formed on the surface of the photosensitive drum (100) to form a toner image.

Next, in the development area (X), the thin film member (91)
The toner (To) remaining on the upper surface is continuously transported in the direction of the arrow (b), and passes through the space between the toner leveling pad (96) and the toner (To).
The consumption pattern of the toner (To) consumed in the developing area (X) is erased, and the surface residual toner layer is made uniform.
Further, the toner (To) is again supplied to the surface of the thin film member (91) by the rotation of the agitator (94), and the blade (9) is rotated.
A uniform thin layer of charged toner is formed at the pressure contact portion 2), and the above operation is repeated again. Hereinafter, the electrostatic latent image developing method of the present invention will be described in more detail using examples.

【Example】

[0046]

[One-component developing method] Manufacturing components of toners A to C : parts by weight Polyester resin (Tuffton NE1110: manufactured by Kao Corporation) 100 Carbon black (MA # 8: manufactured by Mitsubishi Kasei Corporation) 8 Oxidized bottom molecular weight polypropylene (Biscol 550P: Sanyo Chemical) 5 Chromium complex salt type dye (Eizen Spiron Black TRH: Hodogaya Chemical Industry Co., Ltd.) 5

After thoroughly mixing the above materials with a ball mill,
The mixture was kneaded on three rolls heated to 140 ° C. The kneaded material was allowed to cool, coarsely pulverized using a feather mill, and finely pulverized using a jet mill. Thereafter, air classification was performed to produce a toner. Here, by changing the pulverization and classification conditions during production, the average particle diameter is 11.1 μm, 9.0 μm, and 6.
Three types of fine particles a, b, and c of 2 μm were obtained.

With respect to 100 parts by weight of each of the fine particles a, b, and c, 0.5 part by weight of hydrophobic titanium oxide T-805 (manufactured by Degussa: average particle diameter: 30 mμm) and hydrophobic silica HD
KH-2000 (manufactured by Wacker Inc .: average particle diameter 12 mμ)
m) Place 0.2 parts by weight in a Henschel mixer, 150
Mix and stir for 2 minutes at a rotation speed of 0 rpm to obtain fine particles a, b,
c. Titanium oxide and silica fine particles are adhered to each surface by van der Waals force and electrostatically to form toner A,
B and C were obtained.

Production of Toners D to G The surface modification of the fine particles a, b, and c was performed using the apparatus shown in FIG. The fine particles a are particles as they are, and the fine particles b
For and c, 0.5 parts by weight of hydrophobic titanium oxide T-805 was added to a Henschel mixer with respect to 100 parts by weight, and mixed and stirred at 1500 rpm for 2 minutes to deposit titanium oxide. Surface modification was performed under the following conditions to obtain toners D to G.

[0050]

[Table 1]

Further, the toners D to G were subjected to the post-treatment using the post-treatment agents shown in the above table in the same manner as the toners A to C after the surface modification treatment.

Components for Production of Toner H Parts by weight Styrene 100 n-butyl methacrylate 35 2,2-azobis- (2,4-dimethylvaleronitrile) 0.5 Low molecular weight polypropylene (Biscol 605P: Sanyo Chemical Industries) 3 Carbon Black (MA # 8: manufactured by Mitsubishi Kasei Co., Ltd.) Chromium complex salt type dye (Eizen Spiron Black TRH: manufactured by Hodogaya Chemical Industry Co., Ltd.) 3

The above-mentioned materials were mixed with a sand stirrer to prepare a polymerization composition. 3% concentration of this polymer composition
3500 rpm using a stirrer TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.)
The polymerization reaction was carried out at a temperature of 60 ° C. for 6 hours while stirring at m.
After the completion of the polymerization reaction, the resultant was washed with distilled water, dried, and fine particles d having an average particle diameter of 11.3 μm were obtained by air classification. The fine particles d were subjected to post-treatment in the same manner and composition as in Comparative Examples 1 to 3 to obtain a toner H.

[0054]

[Surface Properties of Toners A to H]
The H property of measured by the following method to determine the D / d _50. The density of the toner at this time was 1.1 g / cm ³ .

[0055] Measurement of the average particle diameter of the particle size toner is used call counter multi Sai THE (manufactured by Call Counter Ltd.), was determined by measuring the particle径別relative weight distribution aperture tube of 100 microns.

Specific Surface Area The specific surface area of the particles was measured using a BET one-point measurement apparatus (Flowsorb 2300: manufactured by Shimadzu Corporation). Table 2 shows the results.

[0057]

[Table 2]

[0058]

[Evaluation of Toners A to H] Using the above toners A to H,
A development experiment was performed using the one-component developing apparatus shown in FIG. Developing Device Setting Conditions [Toner Carrier (91)] A conductive cylindrical member having an inner diameter that is 0.5 mm longer than the outer shape of the drive roller. [Photoconductor drum (100)] Organic photoconductor (OPC) Contact pressure with toner carrier 0.2 g / mm Contact width with toner carrier 2 mm [Toner regulating member (92)] Leaf spring member: Silicon at tip A phosphor bronze plate with a rubber pressure of 0.1 mm integrally formed with rubber is in contact with the toner carrier at a contact pressure of 4 to 5 g / mm. [Developing conditions] Surface potential (Vo) -600 V Development bias (V _B ) -250 V Exposure portion potential (Vi) -80 V [Toner layer state] Toner charge amount (Q) -20 to -25 μc / g Toner adhesion amount (M ) ~ 0.5mg / cm ²

Developing The above-mentioned developing device was connected to a printer manufactured by Minolta Camera (85).
mm / sec), and the fog during printing and the state of scattering around characters were evaluated at the initial stage and after 1 × 10 ⁴ printing. Further, the amount of fine powder generated during printing was evaluated by measuring the particle size distribution on the sleeve. Evaluation is 2
Performed in stages.

Evaluation standard fog ○: Indicates that there is no practical problem. ×: fog on a white background is clearly found with the naked eye, lacks sharpness, and impairs practical use.

Scattering ○: The scattering state of the toner around the characters has no practical problem when observed with the naked eye. ×: When the scattering state of the toner around the character is visually observed, the amount of toner scattered between the lines between the characters is clearly large, and the state in which the clarity of the character is hindered. Show.

The content of the fine powder was measured, and the particle size distribution of the toner was measured, and expressed as a ratio (%) of the weight particle size distribution equal to or less than の of the weight average particle size of the toner in the particle size distribution. The evaluation is as follows. ○: less than 1% ×: 1% or more The results are shown in Table 3.

[0063]

[Table 3]

[0064]

[Two-Component Developing Method] Production Components of Toner I Parts by weight Styrene-n-butyl methacrylate (softening point 132 ° C., glass transition temperature 60 ° C.) 100 Carbon black (MA # 8: manufactured by Mitsubishi Kasei Corporation) 8 Low molecular weight polypropylene ( Viscol 550P: Sanyo Kasei Kogyo Co., Ltd. 5 Nigrosine dye (Bontron N-01: Orient Chemical Co., Ltd.) 2 Quaternary ammonium salt (P-51: Orient Chemical Co., Ltd.) 1

After the above materials were sufficiently mixed by a ball mill, they were kneaded on three rolls heated to 140 ° C. The kneaded material was allowed to cool, coarsely pulverized using a feather mill, and further finely pulverized by a jet mill. Thereafter, air classification was performed to obtain a toner I having an average particle size of 8.1 μm.

Production Components of Toner J Parts by weight Styrene-n-butyl methacrylate (softening point 132 ° C., glass transition temperature 60 ° C.) 100 Carbon black (MA # 8: manufactured by Mitsubishi Kasei Corporation) 8 Low molecular weight polypropylene (Viscol 550P: Sanyo) 5 Nigrosine dye (Bontron N-01: manufactured by Orient Chemical Industry Co., Ltd.) 5 Toner J was prepared in the same manner as toner I using the above materials.

Production of Toners K and L The toners I and J were subjected to surface modification under the following conditions using the surface modification apparatus shown in FIG.
The toner K and the toner L were obtained.

[0068]

[Table 4]

The above toners I, J, K and L were subjected to post-treatment of hydrophobic silica R-972 (manufactured by Nippon Aerosil Co., Ltd.) in an amount of 0.2 part by weight based on 100 parts by weight of the toner, and evaluated in an actual machine. Was done.

Manufacture of carrier Carrier A component parts by weight Polyester resin 100 Inorganic magnetic powder (EPT-100: manufactured by Toda Kogyo) 500 Carbon black (manufactured by Mitsubishi Kasei Co., Ltd.) 2 The above materials are sufficiently mixed and crushed by a Henschel mixer, and then Cylinder section 180 ° C, cylinder head section 17
Melt kneading was performed using an extruder kneader set at 0 ° C.
After cooling the kneaded material and coarse pulverization. The resultant was finely pulverized by a jet mill and further classified using an air classifier to obtain a magnetic carrier (carrier A) having an average particle size of 55 μm.

Carrier B The surface of a ferrite carrier core (F-300: manufactured by Powder Tech) was coated with polyethylene by a surface polymerization coating method to obtain a carrier B having an average particle size of 50 μm.

[0072]

Using the above toner I~L [surface properties of the toner I~L] in the same manner as the toner A~H measured toner particle size, the specific surface area was determined to D / d _50. At this time, the toner density is 1.1
was g / cm ^3. Table 5 shows the results.

[0073]

[Table 5]

[0074]

[Evaluation of Toners I to L] Using the above toners I to L and the carrier, a development experiment was conducted by a two-component developing apparatus shown in FIG. Developing device setting conditions [Developing sleeve (54)] Diameter 24.5mm Rotation speed 200rpm Development bias voltage (Vb) Dc-200V [Toner supply roller (32)] Diameter 20mm Rotation speed 200rpm Recovery bias voltage (Vss) Dc-400V, Ac700V AC frequency 300Hz Surface roughness 40μm Micro concave surface area 80% [Gap] Development gap (Ds) 0.6mm Hot height regulation gap (Db) 0.45mm Supply gap (Dss) 0.8mm [Metal blade (38)] Thickness (T) 150 μm Pressing force 0.1 g / mm

Developing The developing apparatus having the above configuration was mounted on a copying machine (EP-470Z), and a developing experiment was performed at a system speed of 13 cm / sec. Solid area ratio (the ratio of the length of the black solid image to the total length in the paper feed direction) of toner when copying a 50% solid black image, uniformity of image quality, unevenness,
The fog and toner spill of the toner on the white background and the toner were evaluated at the initial stage and after printing 1,000 sheets.

The image quality was ranked as follows. ：: Indicates that there is no problem in practical use. X: Lack of black solid uniformity of the solid portion, image unevenness can be clearly recognized by the naked eye, and a problem occurs in image quality, which indicates a problem in practical use.

The toner fog was ranked as follows. ：: Indicates that the level is practically acceptable. ×: fog on a white background is clearly seen with naked eyes, and the sharpness is increased, which indicates that there is a problem in practical use.

The toner spills were ranked as follows. ：: Indicates that the level is practically acceptable. X: Toner spills are clearly observed at the opening of the developing device and around the inside of the developing device, which indicates that there is a problem in practical use. Table 6 shows the results.

[0079]

[Table 6]

[0080]

According to the present invention, a toner having a surface property satisfying conditional expression [I] of the present invention is supplied onto the surface of a toner carrier, and an electrostatic latent image developing and developing using a thin toner layer triboelectrically charged by a regulating member. When used in the method, the fixation, fusion, and filming of the toner on the surface of the regulating member and / or the surface of the toner carrier are suppressed, so that stable high-quality and highly reliable electrostatic latent image development can be performed over a long period of time. .

[Brief description of the drawings]

FIG. 1 shows a schematic flow sheet of a surface modifying device used for modifying the surface of a toner.

FIG. 2 is a schematic configuration diagram of a two-component developing device using the toner of the present invention.

FIG. 3 is a schematic configuration diagram of a two-component developing device using the toner of the present invention.

FIG. 4 is a schematic configuration diagram of a one-component developing device using the toner of the present invention.

[Explanation of symbols]

1: hot air generator, 2, 14, 15, 16: introduction pipe,
3, 17: compressor air, 4: fixed-quantity feeder,
5: sample, 6: hot air injection nozzle, 7: powder injection nozzle,
8: cooling air inlet, 9: cyclone, 10a: cooling water (in), 10b: cooling water (out), 11: product tank, 12: bag filter, 13: blower, 26: magnet, 27: main development Stirring plate, 28: cover support, 29 auxiliary development stirring plate, 30: slit, 31: empty room, 32: toner supply roller (toner carrier), 33: alternating current, 3
4: DC current, 35: partition, 36: support shaft, 37: pressure spring, 38: metal blade (toner regulating member),
39: sheet, 40: empty room, 41: toner return prevention film, 42: toner storage tank, 43: stirring rod, 52: developing tank, 53: casing, 53a: cover, 54: developing sleeve, 64: casing, 66 : Developing sleeve, 6
7: magnetic roller, 68: spike height regulating member, 70: toner supply roller (toner carrier), 71: toner regulating blade (toner regulating member), 76, 78: transport blade, 83: casing, 89: elastic pad, 90 : Developing roller, 9
1: thin film member (toner carrier), 92: press-contact blade (toner regulating member), 94: agitator, 96: toner leveling pad, 100: photosensitive drum

Continuation of the front page (72) Inventor Hiroshi Mizuno Osaka International Building Minolta Camera Co., Ltd. 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka (56) References JP-A-1-185556 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (5)

(57) [Claims] 1. The surface condition has the following conditional expression [I]: 1 ≧ D / d ₅₀ ≧ 0.5, where D = 6 / (ρ · S) [I] [where D is a spherical shape of the toner. represents the conversion grain size ([mu] m) from the specific surface area when it is assumed that; d ₅₀ represents a 50% equivalent particle diameter of the particle径別relative weight distribution of the toner (μm), d ₅₀ is 6μ
m and 11 μm or less; ρ represents the density (g / cm ³ ) of the toner; S represents the BET specific surface area (m ² / g) of the toner, respectively. For toner. 2. The electrostatic latent image developing toner according to claim 1, wherein the toner is a non-magnetic toner. 3. The electrostatic latent image developing toner according to claim 1, wherein the surface property satisfies 1 ≧ D / d ₅₀ ≧ 0.6. 4. The toner according to claim 1, wherein said toner is mixed with hydrophobic silica and hydrophobic titanium oxide.
4. The toner for developing an electrostatic latent image according to any one of items 1 to 3. 5. A method for supplying a toner onto a surface of a toner carrier,
5. An apparatus for forming a thin toner layer triboelectrically charged on said carrier by a regulating member and developing an electrostatic latent image using the toner layer, the electrostatic latent image using the toner according to any one of claims 1 to 4. Image development method.