JPH1020552A - Toner for developing electrostatic latent image and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for developing an electrostatic latent image excellent in transparency to OHP, not causing unevenness in image density and image fog and excellent in blade cleanability and to provide a toner for developing an electrostatic latent image solving the problem of toner fixation on a regulation part. SOLUTION: This toner for developing an electrostatic latent image consists of aggregate particles having 4-10μm vol. average particle diameter and each of the particles consists of polyester resin particles having 0.1-1μm vol. average particle diameter. The polyester resin has 58-70 deg.C glass transition temp., 80-130 deg.C softening point and a number average mol.wt. of 2,000-10,000 and the ratio of the wt. average mol.wt. to the number average mol.wt. is 2-10. This toner is produced as follows; a colored resin soln. consisting of the polyester resin, a colorant and a water-insoluble org. solvent is emulsified and dispersed in water to prepare an oil-in-water type emulsion, the org. solvent is removed from the emulsion and the resultant colored resin particles having 0.1-1μm vol. average particle diameter are aggregated to obtain toner particles made of aggregate particles having 4-10μm vol. average particle diameter.

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 for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like, and a method for producing the same. The present invention relates to an electrostatic latent image developing toner suitable for reproduction and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic apparatus, an analog system such as a copying machine which forms an electrostatic latent image on a photosensitive member by irradiating light from a light source to a document and irradiating reflected light thereof to a photosensitive member. Is generally used. Further, as a digital electrophotographic apparatus for developing by supplying a developer containing toner to an electrostatic latent image obtained by digital writing, a printer used for output of a computer terminal and an image reader are used. Monochrome digital copiers, full-color digital copiers, electrophotographic facsimile machines, and the like that form images based on read image information have been put to practical use.

In a digital electrophotographic apparatus,
An electrostatic latent image is formed in units of dots on the photoreceptor by digital writing such as by irradiating a light beam.
, And the obtained toner image is transferred onto a recording medium such as recording paper and fixed to form a recorded image. As described above, the toner used in the digital method includes:
It is required that the thickness of the dots due to the collapse of the toner at the time of transfer and fixing is small, that is, the dot reproducibility is excellent. If the dot reproducibility is poor, there is a problem that halftone jumps and image collapse occur, and the image quality deteriorates.

Conventionally, as a method for producing toner for developing an electrostatic latent image, for example, a colorant such as carbon black, an organic pigment, or a dye is melt-kneaded in a thermoplastic resin to pulverize a kneaded product of a dispersion. A production method is generally used in which the toner is controlled to a desired particle size and particle size distribution by a device or a classifying device.

Such a method not only requires a large amount of energy for pulverization, but also involves agglomeration during toner storage and toner on the photoreceptor because ultrafine powder generated during pulverization is mixed into the toner. This causes image fogging or the like due to filming. Further, when such a toner is used in a non-magnetic one-component developing system which is adopted as a developing system of a small digital electrophotographic apparatus such as a printer, a vertical streak due to sticking to a regulating blade which is pressed against a developing roller, etc. Cause it.

From such a viewpoint, instead of the pulverization method, there has been proposed a method of producing a toner by a suspension polymerization method capable of obtaining toner particles having a small particle diameter and a relatively uniform particle diameter. The suspension polymerization method is a method for producing toner particles by suspending and polymerizing a polymerization composition containing a polymerizable monomer, a polymerization initiator, a colorant and the like in a dispersion medium.
Since such a suspension polymerization toner is a spherical toner, it solves some of the drawbacks of the toner obtained by the pulverization method, but it has been found that it causes a new drawback.

That is, since the toner particles are spherical, the toner particles easily pass through the blade during cleaning, and the cleaning performance is significantly reduced particularly when the diameter of the toner is reduced. Furthermore, since the polymerizable monomers that can be used for suspension polymerization are limited to vinyl monomers, the resulting binder resin is also limited to vinyl resins, and becomes brittle when the molecular weight is reduced. However, it is not suitable for toner for digital full-color copying machines and digital full-color printers, which require excellent color reproducibility and OHP translucency.

Further, JP-A-2-61650 and JP-A-2-93657 disclose mixing an emulsion-polymerized particle liquid obtained by emulsion-polymerizing a polymerizable monomer with a dispersion obtained by dispersing a colorant and a magnetic powder in water. After that, a method for producing an irregular shaped toner which is coagulated is proposed. According to this method, a small particle size toner having excellent cleaning properties can be obtained.
Because the polymerizable monomers that can be used for emulsion polymerization are limited to vinyl monomers, the resulting binder resin is also limited to vinyl resins, and becomes brittle when the molecular weight is reduced, so it is excellent. In addition, there is a problem that it is not suitable for a toner for a digital full-color copying machine or a digital full-color printer which requires color reproducibility and OHP translucency.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic latent image which solves the above-mentioned problems.

An object of the present invention is to provide a toner for developing an electrostatic latent image capable of obtaining a high-definition image without image density unevenness and image fogging.

Another object of the present invention is to provide an electrostatic latent image developing toner having excellent blade cleaning properties.

It is another object of the present invention to provide color reproduction and O
An object of the present invention is to provide a toner for developing an electrostatic latent image capable of obtaining an image having excellent HP light transmission.

Another object of the present invention is to provide a toner for developing an electrostatic latent image which solves the problem of sticking at a pressure contact portion (regulation portion) between a development roller and a regulation blade even when used in a non-magnetic one-component development system. Is to provide.

Another object of the present invention is to provide a method for producing a toner for developing an electrostatic latent image which solves the above-mentioned problems.

[0015]

According to the present invention, a glass transition point of 58 to 70 ° C, a softening point of 80 to 130 ° C, and a number average molecular weight of 2 are provided.
2,000 to 10,000 and a weight average molecular weight / a number average molecular weight of 2 to 10 polyester resin having a volume average particle diameter of 0.1 to 1 μm. The present invention relates to a toner for developing an electrostatic latent image having a thickness of 4 to 10 μm.

The present invention also provides a glass transition point of 58 to 70.
° C, softening point 80-130 ° C, number average molecular weight 2000-1
0000 and weight-average molecular weight / number-average molecular weight 2-1
A color resin solution comprising a polyester resin, a colorant and a water-insoluble organic solvent is emulsified and dispersed in water to form an O / W
A colored emulsion having a volume average particle diameter of 0.1 to 1 μm is formed by removing the organic solvent, and then the colored resin particles are aggregated to form a coagulated resin having a volume average particle diameter of 4 to 10 μm. The present invention relates to a method for producing a toner for developing an electrostatic latent image to obtain toner particles composed of aggregated particles.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The toner of the present invention has a volume average particle diameter of at least 0.1 to at least a specific polyester resin.
It is composed of aggregate particles of 1 μm resin particles, and the volume average particle diameter of the aggregate particles is 4 to 10 μm, preferably 4 to 8 μm.
m.

When the volume average particle size of the resin particles is smaller than 0.1 μm, it is difficult to sufficiently improve the blade cleaning property. When the volume average particle size is larger than 1 μm, the aggregate particles having the above particle size can be produced stably. Becomes difficult.

As the binder resin used for the resin particles constituting the toner of the present invention, a polyester resin is preferably used.

The softening point of the polyester resin is 80 to 13.
0 ° C, preferably 90 to 125 ° C. Softening point is 80
If the temperature is lower than 130 ° C., the toner is likely to be aggregated during storage. If the temperature is higher than 130 ° C., the fixability deteriorates, and the translucency decreases when used as a full-color toner. The softening point is a ring and ball type automatic softening point tester (Akimine Sha:
25D5-ASP-M4SP type).

The glass transition point of the polyester resin is 58.
When the temperature is lower than 58 ° C, there is a problem in storage stability, and when it is higher than 70 ° C, the light transmittance is poor. The glass transition point is determined by JIS using a differential scanning calorimeter (DSC) DSC220C manufactured by Seiko Denshi Kogyo.
It measured according to K-7121.

The molecular weight of the polyester resin is such that the number average molecular weight (Mn) is 2,000 to 10,000, preferably 30.
00-8000, weight average molecular weight (Mw) / number average molecular weight (Mn) is 2-10, preferably 3-7. If the number average molecular weight is less than 2,000, aggregation and stability during storage are poor, and if it is more than 10,000, light transmittance is poor. M
If w / Mn is lower than 2, it is difficult to manufacture, and
If it is higher, there is a problem in light transmission. The molecular weight of the binder resin was measured using an HLC-8020 with a GPC measuring device manufactured by Toso-, and the columns were TSK-G-5000HXL, manufactured by Toso-
Using four 000HXL, 3000HXL, and 2000HXL, measurement was performed with a 0.35 w / v% tetrahydrofuran solution, and a calibration curve was created with standard polystyrene.

The acid value of the polyester resin is 2 to 30 mg.
KOH / g, preferably 5 to 25 mgKOH / g. If it is less than 2, the dispersibility of the colorant and the charge control agent is poor, and if it is more than 30, there is a problem in charge stability due to the influence of humidity.

The acid value is determined by dissolving the resin in toluene, neutralizing and titrating with a 1 / 10N-methanol solution of potassium hydroxide using phenolphthalene as an indicator.

[0025]

(Equation 1)

In the above formula, V represents the usage amount (ml) of a 1 / 10N-methanol solution of potassium hydroxide, and F represents 1/1
Represents the titer of 0N-potassium hydroxide methanol solution,
Represents the sampled amount (g). In the present invention, measurement was performed twice, and the average value was taken as the acid value.

The polyester resin preferably contains etherified diphenols as the alcohol component and aromatic dicarboxylic acids as the acid component.

As the above etherified diphenols,
For example, polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene ( 2,0)-
2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2)-
2,2-bis (4-hydroxyphenyl) propane and the like can be mentioned.

Further, together with the above etherified diphenols, diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, etc. Kind,
Sorbitol, 1,2,3,6-hexanetetrol,
1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,2
4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2
-Methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like may be used.

As the aromatic dicarboxylic acids, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, acid anhydrides thereof and lower alkyl esters thereof can be used.

Further, aliphatic dicarboxylic acids such as fumaric acid, maleic acid, succinic acid, alkyl or alkenyl succinic acids having 4 to 18 carbon atoms, and aliphatic dicarboxylic acids such as acid anhydrides or lower alkyl esters thereof are used. You may.

Further, 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,
2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanenetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, Polyvalent carboxylic acids such as 4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, anhydrides thereof and lower alkyl esters are used as acid values of polyester resins. Adjustment of,
For the purpose of improving the resin strength, a small amount may be used as long as the translucency is not impaired.

As the polyester resin, a urethane-modified polyester resin obtained by reacting a polyester resin with an isocyanate, an acryl-modified polyester resin, and the like can also be used.

As the coloring agent used in the present invention, known coloring agents can be used. For example, carbon black,
C. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, Mineral Fast Yellow, Navel Yellow, Naphthol Yellow S, Hansai Yellow G, Permanent Yellow NCG, Permanent Orange GTR, Benzidine Orange G, Permanent Red 4R, Brilliant Carmine 3B, Fast Bio Red B, Victoria Blue Lake Quinacridone, rhodamine lake, phthalocyanine blue, fast sky blue, pigment green B, final yellow green G, and the like, and are not particularly limited.

These colorants can be used alone or as a mixture of two or more kinds in an amount of 2 to 10 parts by weight with respect to the binder resin.

In the present invention, it is preferable to add a charge control agent to the binder resin in order to control the chargeability of the toner.

As the charge control agent, known charge control agents can be used and are not particularly limited. As the negative charge control agent used for the color toner, a colorless, white or light-colored charge control agent that does not adversely affect the color tone and light transmittance of the color toner can be used.For example, a salicylic acid metal complex such as a zinc complex of a salicylic acid derivative can be used. It is preferable to use a charge control agent such as a calixarene-based compound, an organic boron compound, and a fluorinated quaternary ammonium salt compound alone or in combination of two or more. The salicylic acid metal complex is disclosed in, for example, JP-A-53-127.
No. 726, JP-A-62-145255, etc., as calixarene-based compounds, for example, those described in JP-A-2-201378, etc. The compounds described in JP-A-221967 and the like, and the fluorine-containing quaternary ammonium salt-based compounds described in, for example, JP-A-3-1162 can be used.

When such a charge control agent is added,
It is preferable to use 0.1 to 7 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the binder resin.

In the present invention, wax or the like may be used as necessary. Known waxes are used as these waxes, for example, low molecular weight polypropylene wax, low molecular weight polyethylene wax, low molecular weight oxidized polypropylene wax, low molecular weight oxidized polyethylene wax, carnauba wax, sasol wax, candelilla wax, Jojoba oil wax or the like can be used alone or in combination of two or more. The addition amount of these waxes is 0.5 to 6 with respect to 100 parts by weight of the binder resin.
Parts by weight, preferably 1 to 5 parts by weight, and a softening point of 70 parts by weight.
C. to 150 C. can be suitably used.

The toner of the present invention has a BET specific surface area of 20.
Inorganic fine particles surface-treated with a hydrophobizing agent at up to 300 m ² / g are mixed and used. Known inorganic fine particles are used, and examples thereof include silica fine particles, titanium fine particles, alumina fine particles, magnesium fluoride fine particles, silicon carbide fine particles, and strontium titanate fine particles. These microparticles are silane coupling agents, titanium coupling agents, aluminum coupling agents, hydrophobizing agents such as silicone oils, which have been subjected to a surface treatment so that the degree of hydrophobicity is 30 or more, preferably 40 or more. It is preferred to use.
By adding such inorganic fine particles, it is possible to solve the problem of fogging due to environmental stability, in particular, a decrease in toner charge amount at high temperature and high humidity.

From the viewpoint of improving the fluidity and preventing the toner charge amount from decreasing at high temperature and high humidity, preferred inorganic fine particles include BE.
T specific surface area of 100 to 300 m ² / g, preferably 12
Silica fine particles having a hydrophobicity of 30 or more at 0 to 250 m ² / g are exemplified.

From the viewpoint of improving the environmental stability, in particular, preventing the image density from lowering due to charge-up in a low temperature and low humidity environment, B
ET specific surface area of 20 to 150 m ² / g, preferably 30
It is preferable to use titania fine particles of about 130 m ² / g, and it is preferable that the titania fine particles also have a hydrophobicity of 50 or more from the viewpoint of the above environmental stability. As the titania fine particles, anatase titania, rutile titania, amorphous titania and the like can be used.

From this viewpoint, two or more kinds of fine particles having different functions as described above may be used in combination as the inorganic fine particles. The 100 to 300 m ² / g of silica fine particles and 20~150m ² / g of the combination of the titania fine particles are preferably, 120~250m ² / g of silica fine particles and 3
It is particularly preferred to use 0 to 130 m ² / gm of titania fine particles in combination.

The amount of addition of such inorganic fine particles is 0.05 to 2% by weight, preferably 0.1 to 1% by weight, based on the toner.
5% by weight.

In order to improve the cleaning property, inorganic fine particles having a number average particle size of 0.1 to 2 μm, emulsion polymer fine particles having a number average particle size of 0.05 to 2 μm, soap-free emulsion polymer fine particles, Resin particles such as water-dispersed fine particles and fluorine-based resin fine particles may be used alone or in combination of two or more.

In the present invention, first, a colored resin solution comprising the above polyester resin, a colorant and a water-insoluble organic solvent is prepared.

The water-insoluble organic solvent contains a toner composition (a polyester resin, a colorant and, if necessary, a charge control agent,
Wax, etc.) for dissolving or dispersing, for example, toluene, benzene, xylene, methylene chloride, chloroform, carbon tetrachloride, dimethyl ether, diethyl ether, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate Butyl propionate, dimethyl oxalate, diethyl oxalate, dimethyl succinate, diethyl succinate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol monoacetate, diethylene glycol monoacetate, ethanol, propanol, butanol,
Diacetone alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethylformamide, 2-methoxyethanol, 2-ethoxyethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene Glycol monoethyl ether, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, etc. can be used alone or in combination of two or more.

To dissolve or disperse the binder resin, the colorant, and other toner components in the water-insoluble organic solvent,
An apparatus such as a ball mill, a sand mill, a homomixer, and an ultrasonic homogenizer can be used.

Next, the above colored resin solution is emulsified and dispersed in an aqueous medium to form an O / W emulsion. O /
The W-type emulsion refers to a suspension in which an oily liquid is dispersed as droplets in an aqueous medium.

It is preferable to add an appropriate dispersion stabilizer to such an aqueous medium. For example, polyvinyl alcohol, gelatin, gum arabic, methylcellulose, ethylcellulose, methylhydroxypropylcellulose, sodium salt of carboxymethylcellulose, sodium dodecylbenzenesulfonate, sodium dodecylbenzenesulfonate, sodium octylsulfate, sodium laurate, calcium phosphate, magnesium phosphate, Aluminum phosphate, calcium carbonate, magnesium carbonate,
Barium sulfate, bentonite and the like can be mentioned, and these dispersion stabilizers can be used in an amount of 0.05 to 3% by weight.

In order to form an O / W emulsion, a method of sufficiently stirring a mixed system of a colored resin solution and an aqueous medium using a stirrer such as a homomixer can be adopted.

In the present invention, the O / W emulsion is heated while stirring to remove the water-insoluble organic solvent, whereby the suspension in which the colored resin particles of 0.1 to 1 μm are dispersed in the aqueous medium. Obtain a liquid. A coagulant is added to the suspension to coagulate the colored resin particles, and after heat treatment, the aqueous medium is removed to isolate the aggregate particles, washed and dried, and if necessary, classified. To obtain toner particles. The toner particles thus obtained have excellent cleaning properties because their shapes are not truly spherical.

The coagulant used in the present invention includes, for example, magnesium sulfate, aluminum sulfate, barium chloride,
Calcium chloride, sodium chloride and the like and / or a mixture thereof with an inorganic acid such as hydrochloric acid and sulfuric acid.

It is preferable to use these flocculants as aqueous solutions of 0.1 to 10% by weight, preferably 0.5 to 8% by weight.

The toner of the present invention has a shape factor SF1 of 120 to 160, preferably 13 as an average value of 100 toners.
0 to 150. If SF1 is 120 or less, it becomes spherical and a problem arises in cleaning properties. If SF1 is 160 or more, it becomes indefinite and the toner surface is chipped to generate fine powder, resulting in a problem in durability.

The shape factor SF1 is a parameter indicating a difference between the major axis and the minor axis (distortion property) of the particle. The value becomes closer to 100 as the particle shape becomes closer to a sphere.

The shape factor SF1 is measured by an image analyzer (Luzex 500: manufactured by Nippon Regulator Co., Ltd.) in the present invention, and the shape factor SF defined by the following equation is obtained.
1 is shown.

[0058]

(Equation 2)

In the above formula, the maximum length indicates the average value of the maximum length in the projected image of the particle, and the area indicates the average value of the projected area of the particle.

The toner of the present invention can be used as a one-component developer or a two-component developer, but is preferably used as a non-magnetic one-component developer. Particularly, the toner has good characteristics for a non-magnetic one-component developing device in which a regulating blade is pressed against a developing sleeve to form a thin toner layer on the surface of the developing sleeve.

When used as a two-component developer,
Carriers include iron powder carriers, ferrite carriers,
Binder type carriers and coated carriers can be used. As the coated carrier, a carrier core material such as the iron powder carrier, ferrite carrier or binder type carrier is coated with a thermoplastic or thermosetting resin such as a silicone resin, an acrylic resin, a polyester resin, or a polyolefin resin. Just use it. These carriers have a volume average particle size of 20 to 100 μm, preferably 3 to 100 μm.
0 to 90 μm and an electric resistance value of 1 × 10 ⁷ to 1
× 10 ¹⁴ Ω · cm, preferably 1 × 10 ⁸ to 1 × 10 ¹³
Ω · cm is good.

[0062]

【Example】

(Example 1) Polyoxyethylene (2,2) -2,2-bis (4-hydroxyphenyl) propane was placed in a 10-liter four-necked flask equipped with a stirrer, a distillation column, an inert gas inlet tube, and a thermometer. 2200 parts by weight, 120 parts by weight of neopentyl glycol, 1100 parts by weight of terephthalic acid and 200 parts by weight of isophthalic acid were charged, and heated to 180 ° C. in a stream of nitrogen gas, and 5 parts by weight of dibutyltin oxide was added thereto and heated for 2 hours. did. Next, the temperature was raised to 230 ° C., water did not distill from the distillation column, and the acid value was 5.2.
KOH mg / g, react until softening point reaches 122 ° C,
Polyester resin A was obtained.

The polyester resin A has a glass transition point of 6
At 2 ° C., the number average molecular weight was 4,500, and the weight average molecular weight / number average molecular weight was 3.6.

Next, 10 parts by weight of a polyester resin A, 0.8 parts by weight of a colorant (KET-Blue 102: manufactured by Dainippon Ink and Chemicals, Inc.), and a negative charge control agent (Bontron E-8)
1: Orient Chemical Industry Co., Ltd.), 0.7 parts by weight, 70 parts by weight of toluene and 30 parts by weight of methylene chloride were mixed by a ball mill to prepare a colored resin solution.

On the other hand, a thermometer and a stirrer were attached to a 3-liter three-necked flask, and a dispersant (sodium dodecylbenzenesulfonate) 0.5 was added to 2 liters of ion-exchanged water.
% By weight and 0.5% by weight of polyvinyl alcohol were dissolved to prepare an aqueous medium.

The above colored resin solution was suspended in an aqueous medium using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and
A W emulsion was formed. At this time, stirring was performed at a rotation speed of the TK homomixer of 8500 rpm for 30 minutes. Thereafter, the mixed solvent was removed by heating while stirring the TK homomixer at a rotation speed of 200 rpm, and the volume average particle diameter was 0.9 μm.
Thus, an aqueous medium in which m colored resin particles were suspended was obtained. 100
An aqueous solution obtained by dissolving 14 g of magnesium sulfate in milliliter of ion-exchanged water was uniformly dropped into the colored resin particle suspension for 15 minutes to aggregate the colored resin particles, and then the temperature was further raised to 80 ° C. Heat treatment was performed for 30 minutes.
The suspension was filtered, washed with ion-exchanged water 4 to 5 times, and dried. The obtained aggregate particles were classified by a classifier (Elbow Jet: manufactured by Matsusaka Trading Co., Ltd.), and the volume average particle size was 6.0.
μm toner particles were obtained. Shape factor S of this toner particle
F1 was 135.

The particles were treated with hydrophobic silica (BET specific surface area 210 m ² / g, degree of hydrophobicity 35, Taranox 5).
00: manufactured by Talco Co.) was mixed with a Henschel mixer (2500 rpm, 90 seconds) to obtain a negatively chargeable toner A.

Example 2 Polyoxyethylene (2,
2) -2,2-bis (4-hydroxyphenyl) propane 3700 parts by weight, polyoxyethylene (2,2)-
2,2-bis (4-hydroxyphenyl) propane 20
0 parts by weight, 1700 parts by weight of isophthalic acid and 30 parts by weight of terephthalic acid except that the acid value was 10.8 KOH mg / g and the polyester resin B was reacted until the softening point reached 103 ° C. in the same manner as in Example 1. Obtained.

The polyester resin B has a glass transition point of 6
8.4 ° C., number average molecular weight 4700, weight average molecular weight /
The number average molecular weight was 7.1.

Next, 10 parts by weight of a polyester resin B, 0.6 parts by weight of a colorant (KET-Red 305: manufactured by Dainippon Ink and Chemicals, Inc.), and a charge control agent (Bontron E-84:
0.5 parts by weight, toluene 70
By weight, 25 parts by weight of methylene chloride and 5 parts by weight of methyl ethyl ketone were mixed by a ball mill to prepare a colored resin solution.

On the other hand, a thermometer and a stirrer were attached to a 3-liter 3-necked flask, and a dispersant (sodium dodecylbenzenesulfonate) 0.5 was added to 2 liters of ion-exchanged water.
% By weight and 0.5% by weight of polyvinyl alcohol were dissolved to prepare an aqueous medium.

The above colored resin solution was suspended in an aqueous medium using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and
A W emulsion was formed. At this time, the TK homomixer was stirred at 11,000 rpm for 30 minutes.
Thereafter, the mixed solvent was removed by heating while stirring the TK homomixer at a rotation speed of 200 rpm, and the volume average particle diameter was 0.6.
An aqueous medium in which 5 μm of colored resin particles were suspended was obtained. 1
An aqueous solution in which 14 g of aluminum sulfate was dissolved in 00 ml of ion-exchanged water was added to the colored resin particle suspension in an amount of 1%.
After dropping uniformly in 5 minutes to aggregate the colored resin particles,
Further, the temperature of the liquid was raised to 80 ° C. and heat treatment was performed for 30 minutes. The suspension was filtered, washed with ion-exchanged water 4 to 5 times, and dried. The obtained aggregate particles were classified by a classifier (Elbow Jet: manufactured by Matsusaka Trading Co., Ltd.) to obtain toner particles having a volume average particle size of 5.5 μm. The shape factor SF1 of the toner particles was 132.

The particles were treated with hydrophobic titania (BET).
Specific surface area 104 m ² / g, degree of hydrophobicity 63, STT30D
S: Titanium Industry Co., Ltd.) was mixed by a Henschel mixer (3000 rpm, 180 seconds) at 1.0% by weight, and then hydrophobic silica (Taranox 500: Talco) 0.3
The weight% was mixed at 2500 rpm for 60 seconds to obtain a negatively chargeable toner B.

Example 3 10 parts by weight of a polyester resin A, 0.8 parts by weight of a colorant (KET-Yellow 305: manufactured by Dainippon Ink and Chemicals, Inc.), and a charge control agent (Bontron E-84: manufactured by Orient Chemicals) 0.7 parts by weight,
90 parts by weight of toluene and 10 parts by weight of diethyl ether were mixed by a ball mill to prepare a colored resin solution.

On the other hand, a thermometer and a stirrer were attached to a 3-liter three-necked flask, and a dispersant (sodium dodecylbenzenesulfonate) 0.2 was added to 2 liters of ion-exchanged water.
% By weight and Metroze 60SH (Shin-Etsu Chemical Co., Ltd.)
5 wt% was dissolved to prepare an aqueous medium.

The above colored resin solution was suspended in an aqueous medium using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and
A W emulsion was formed. At this time, the TK homomixer was stirred at 8000 rpm for 30 minutes. Thereafter, the mixed solvent was removed by heating while stirring at a rotation speed of 150 rpm of a TK homomixer, and the volume average particle diameter was 1.0 μm.
Thus, an aqueous medium in which m colored resin particles were suspended was obtained. 100
An aqueous solution obtained by dissolving 10 g of aluminum sulfate in milliliter of ion-exchanged water was uniformly dropped into the colored resin particle suspension over 15 minutes to aggregate the colored resin particles, and then the temperature was further raised to 80 ° C. Heat treatment was performed for 30 minutes.
The suspension was filtered, washed with ion-exchanged water 4 to 5 times, and dried. The obtained aggregate particles were classified by a classifier (Elbow Jet: manufactured by Matsusaka Trading Co., Ltd.), and the volume average particle size was 9.4.
μm toner particles were obtained. Shape factor S of this toner particle
F1 was 153.

The particles were mixed with 0.4% by weight of hydrophobic silica (Taranox 500, manufactured by Talco) using a Henschel mixer (2500 rpm, 90 seconds) to obtain a negatively chargeable toner C.

Example 4 Polyoxyethylene (2,
2) The acid was prepared in the same manner as in Example 1 except that 2,180 parts by weight of 2,2-bis (4-hydroxyphenyl) propane, 86 parts by weight of neopentyl glycol, 40 parts by weight of ethylene glycol and 1,400 parts by weight of terephthalic acid were used. The polyester resin C was reacted until the titer reached 3.8 KOH mg / g and the softening point reached 125 ° C.

The polyester resin C has a glass transition point of 6
7.0 ° C., number average molecular weight 5200, weight average molecular weight /
The number average molecular weight was 3.5.

Next, 10 parts by weight of a polyester resin C, 0.8 parts by weight of a colorant (KET-Red 309: manufactured by Dainippon Ink and Chemicals, Inc.), and an offset inhibitor (oxidized polypropylene, Viscol TS-200: manufactured by Sanyo Chemical Industries, Ltd.) )
0.5 parts by weight, 0.7 parts by weight of a charge control agent (Bontron E-81: manufactured by Orient Chemical Industries), 70 parts by weight of toluene, 25 parts by weight of methylene chloride and 5 parts by weight of methyl ethyl ketone are mixed by a ball mill, and a colored resin solution is mixed. Was adjusted.

On the other hand, a thermometer and a stirrer were attached to a 3-liter 3-neck flask, and a dispersant (sodium dodecylbenzenesulfonate) 0.2 was added to 2 liters of ion-exchanged water.
% By weight and 0.5% by weight of polyvinyl alcohol were dissolved to prepare an aqueous medium.

The above colored resin solution was suspended in an aqueous medium using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and
A W emulsion was formed. At this time, stirring was performed at a rotation speed of the TK homomixer of 8500 rpm for 30 minutes. Thereafter, the mixed solvent was removed by heating while stirring the TK homomixer at a rotation speed of 200 rpm, and the volume average particle diameter was 0.9 μm.
Thus, an aqueous medium in which m colored resin particles were suspended was obtained. 100
An aqueous solution obtained by dissolving 15 g of aluminum sulfate in milliliter of ion-exchanged water was uniformly dropped into the colored resin particle suspension for 15 minutes to aggregate the colored resin particles, and then the liquid temperature was further increased to 80 ° C. Heat treatment was performed for 30 minutes.
The suspension was filtered, washed with ion-exchanged water 4 to 5 times, and dried. The obtained aggregate particles were classified by a classifier (Elbow Jet) to obtain toner particles having a volume average particle size of 8.5 μm. The shape factor SF1 of the toner particles was 142.

The particles were mixed with 0.4% by weight of hydrophobic silica (Taranox 500, manufactured by Talco) using a Henschel mixer (2500 rpm, 90 seconds) to obtain a negatively chargeable toner D.

Example 5 A 10-liter four-necked flask equipped with a stirrer, a distillation column, an inert gas inlet tube, and a thermometer was charged with polyoxyethylene (2,2) -2,2-bis (4-hydroxy). 1400 parts by weight of phenyl) propane,
100 parts by weight of diethylene glycol, isophthalic acid 70
Then, 0 parts by weight and 30 parts by weight of phthalic anhydride were charged, and the temperature was raised to 185 ° C. in a stream of nitrogen gas, and 7 parts by weight of dibutyltin oxide was added thereto and heated for 2 hours. Then 22
The temperature was raised to 0 ° C., water did not evaporate from the distillation column, and the reaction was carried out until the acid value became 7.6 KOH mg / g and the softening point became 128 ° C., thereby obtaining a polyester resin D.

The polyester resin D has a glass transition point of 6
2.5 ° C., number average molecular weight 8300, weight average molecular weight /
The number average molecular weight was 4.1.

Next, 10 parts by weight of a polyester resin D, 0.8 parts by weight of a colorant (KET-Red 309: manufactured by Dainippon Ink and Chemicals, Inc.), and a charge control agent (Bontron E-81:
0.7 parts by weight, toluene 75
Parts by weight and 25 parts by weight of methylene chloride were mixed by a ball mill to prepare a colored resin solution.

On the other hand, a thermometer and a stirrer were attached to a 3-liter three-necked flask, and a dispersant (sodium dodecylbenzenesulfonate) 0.2 was added to 2 liters of ion-exchanged water.
% By weight and 0.6% by weight of polyvinyl alcohol were dissolved to prepare an aqueous medium.

The above colored resin solution was suspended in an aqueous medium using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and
A W emulsion was formed. At this time, stirring was performed at a rotation speed of the TK homomixer of 11500 rpm for 30 minutes.
Thereafter, the mixed solvent was removed by heating while stirring the TK homomixer at a rotation speed of 200 rpm, and the volume average particle diameter was 0.6.
An aqueous medium in which μm colored resin particles were suspended was obtained. 10
An aqueous solution obtained by dissolving 17 g of aluminum sulfate in 0 ml of ion-exchanged water was added to the colored resin particle suspension in an amount of 15%.
After the solution was uniformly dropped over a period of 1 minute to aggregate the colored resin particles, the temperature of the solution was further increased to 80 ° C., and a heat treatment was performed for 30 minutes. The suspension was filtered, washed with ion-exchanged water 4 to 5 times, and dried. The obtained aggregate particles were classified by a classifier (Elbow Jet) to obtain toner particles having a volume average particle diameter of 6.2 μm. The shape factor SF1 of the toner particles is 13
It was 2.

The particles were mixed with 0.6% by weight of hydrophobic silica (Taranox 500: manufactured by Talco) using a Henschel mixer (2500 rpm, 90 seconds) to obtain a negatively chargeable toner E.

(Comparative Example 1) In Example 1, the amount of the polyester resin A was 18
Parts by weight, and changing the number of revolutions of the TK homomixer to 3000 rpm when suspending the colored resin solution in the aqueous medium, in the same manner as in Example 1 except that the volume average particle size is 4.5 μm.
m of the colored resin particle suspension was obtained, and toner particles having a volume average particle diameter of 15.5 μm were obtained in the same manner as in Example 1. The shape factor SF1 of the toner particles was 173.

The particles were mixed with 0.5% by weight of hydrophobic silica (Taranox 500, manufactured by Talco) using a Henschel mixer (2500 rpm, 90 seconds) to obtain a negatively chargeable toner F.

(Comparative Example 2) In Example 1, the amount of the polyester resin A added in preparing the colored resin solution was 0.1%.
5 parts by weight, and changing the number of revolutions of the TK homomixer to 12,000 rpm for suspending the colored resin solution in the aqueous medium, in the same manner as in Example 1, except that the volume average particle diameter is 0.1.
A color resin particle suspension of 08 μm was obtained, and toner particles having a volume average particle size of 9.5 μm were obtained in the same manner as in Example 1. The shape factor SF1 of the toner particles was 118.

0.5% by weight of hydrophobic silica (Taranox 500: manufactured by Talco) was mixed with the particles using a Henschel mixer (2500 rpm, 90 seconds) to obtain a negatively chargeable toner G.

Comparative Example 3 Neopentyl glycol 45
The acid value was 4 in the same manner as in Example 1 except that 0 parts by weight, 95 parts by weight of ethylene glycol, 45 parts by weight of trimethylolpropane and 500 parts by weight of terephthalic acid were used.
The reaction was performed until 3.2 KOH mg / g and the softening point reached 89.2 ° C., thereby obtaining a polyester resin E.

The polyester resin E has a glass transition point of 5
3.2 ° C., number average molecular weight 3300, weight average molecular weight /
The number average molecular weight was 4.4.

A negatively chargeable toner H having a volume average particle size of 5.8 μm and a shape factor SF1 of 130 was obtained in the same manner as in Example 1 except that the polyester resin E was used.

Comparative Example 4 Polyoxyethylene (2,
2) 1,400 parts by weight of 2,2-bis (4-hydroxyphenyl) propane, 100 parts by weight of diethylene glycol, 845 parts by weight of isophthalic acid and 35 of terephthalic acid
A polyester resin F was obtained by reacting until the acid value became 8.7 KOH mg / g and the softening point became 148 ° C. in the same manner as in Example 1 except for using parts by weight.

The polyester resin F has a glass transition point of 6
4.2 ° C., the number average molecular weight was 14,800, and the weight average molecular weight / number average molecular weight was 3.0.

A negatively chargeable toner I having a volume average particle diameter of 6.2 μm and a shape factor SF1 of 138 was obtained in the same manner as in Example 1 except that the polyester resin F was used.

Comparative Example 5 A 10-liter four-necked flask equipped with a stirrer, a distillation column, an inert gas inlet tube, and a thermometer was charged with polyoxyethylene (2,2) -2,2-bis (4-hydroxy). Phenyl) propane 4800 parts by weight,
90 parts by weight of propylene glycol, 150 of isophthalic acid
0 parts by weight and 480 parts by weight of phthalic anhydride were charged and heated to 185 ° C. in a stream of nitrogen gas, whereupon 6 parts by weight of dibutyltin oxide was added and heated for 2 hours. Then 2
The temperature was raised to 40 ° C., and water did not evaporate from the distillation column, and the reaction was performed until the acid value reached 6.3 KOH mg / g and the softening point reached 123 ° C., thereby obtaining a polyester resin G.

The polyester resin G has a glass transition point of 7
7.9 ° C., the number average molecular weight was 12,500, and the weight average molecular weight / number average molecular weight was 3.8.

A negatively chargeable toner J having a volume average particle diameter of 6.0 μm and a shape factor SF1 of 135 was obtained in the same manner as in Example 1 except that the polyester resin G was used.

Comparative Example 6 A 10-liter four-necked flask equipped with a stirrer, a distillation column, an inert gas inlet tube, and a thermometer was charged with polyoxyethylene (2,2) -2,2-bis (4-hydroxy). Phenyl) propane 5100 parts by weight,
1,500 parts by weight of isophthalic acid and 70 parts by weight of phthalic anhydride were charged and heated to 185 ° C. in a nitrogen gas stream.
Then, 5 parts by weight of dibutyltin oxide was added and heated for 2 hours. Then, the temperature was raised to 240 ° C., water did not evaporate from the distillation column, and the reaction was performed until the acid value became 55.9 KOH mg / g and the softening point became 79 ° C., to obtain a polyester resin H.

The polyester resin H has a glass transition point of 5
7.2 ° C., number average molecular weight 1600, weight average molecular weight /
The number average molecular weight was 8.0.

A negatively chargeable toner K having a volume average particle diameter of 6.0 μm and a shape factor SF1 of 140 was obtained in the same manner as in Example 1 except that the polyester resin H was used.

Table 1 shows the physical property values of the binder resins used and the obtained toner particles and the like for the toners A to K.

[0107]

[Table 1]

The toners A to K were subjected to the following process using an electrophotographic printer (SP1000: manufactured by Minolta) equipped with a non-magnetic one-component developing device having a developing sleeve and a regulating blade one end of which was pressed against the developing sleeve. Was evaluated, and the results are shown in Table 2.

(Image Density) At the initial stage and at the end of 10,000-sheet printing, the image density was measured with a Sakura densitometer (manufactured by Konica Corporation). A sample less than 1.2 was marked as “△”, and a sample less than 1.2 was marked as “x”.

(Image density unevenness) At the initial stage and at the end of 10,000-sheet printing, the image density was measured with a Sakura Densitometer (manufactured by Konica Corporation).濃度, 0.2 when the density difference between the solid black image and
The sample having a value of 0.4 or less was rated as Δ, and the sample having a value of 0.4 or more was rated X.

(Cleaning) At the initial stage and at the end of 10,000-sheet printing, the surface of the photoreceptor after passing through the cleaning blade is visually observed. Those that were practically problematic but were not rated, and those that had unwiped residue and had a practical problem were rated X.

(OHP translucency) A solid image is formed on an OHP film at the initial stage and at the end of 10,000-sheet printing.
The color vividness when projected by an overhead projector was visually evaluated.も の indicates that the color reproducibility was excellent, △ indicates that it could be used practically, and x indicates that the chroma was poor.

(Fog) At the initial stage and at the end of 10,000-sheet printing, fog on a white background portion of the image was visually observed.
い な い indicates that no fogging has occurred, Δ indicates that some fogging has occurred and has no practical problem, and x indicates that fogging has occurred and has practical problems.

(Adhesion of the Regulator) The blade surface of the regulator (the pressure-contact portion between the blade and the sleeve) was observed with a metal microscope at the initial stage and at the end of 10,000-sheet printing. If the toner is not fixed on the blade and no white stripes are formed on the image, the result is ○. The toner is fixed on the blade but no white stripe is formed on the image and there is no practical problem. The sample was rated "A", and the sample having a practical problem due to white streaks due to toner adhesion on the image was rated "x".

[0115]

[Table 2]

Since the toner of Comparative Example 1 has a large particle to be agglomerated, the toner particle size is large and the image is rough. In addition, the toner shape becomes irregular and toner fine powder is generated, resulting in poor durability. In the toner of Comparative Example 2, since the particles to be aggregated are small, the toner shape is spherical, and cleaning failure occurs. Since the toner of Comparative Example 3 has a low glass transition point, the toner adheres to the regulating portion and is inferior in durability. Since the toners of Comparative Examples 4 and 5 have high molecular weights, glass transition points, and softening points, they have poor light transmission to OHP. Since the toner of Comparative Example 6 has a low molecular weight and a low softening point, the toner adheres to the regulating portion and is inferior in durability.

[0117]

According to the present invention, color reproducibility and OHP
And a toner for developing an electrostatic latent image capable of obtaining an image having excellent light transmittance.

Further, according to the present invention, it is possible to provide an electrostatic latent image developing toner capable of obtaining a high-definition image without image density unevenness and image fogging.

Further, according to the present invention, it is possible to provide an electrostatic latent image developing toner having excellent blade cleaning properties.

Further, according to the present invention, even when used in the non-magnetic one-component developing system, the toner for developing an electrostatic latent image which has solved the problem of sticking at the pressure contact portion (regulating portion) between the developing roller and the regulating blade is provided. Can be provided.

Claims (7)

[Claims] 1. A glass transition point of 58 to 70 ° C. and a softening point of 80.
-Aggregate particles of resin particles having a volume average particle diameter of 0.1 to 1 µm and a polyester resin having a number average molecular weight of 2000 to 10000 and a weight average molecular weight / number average molecular weight of 2 to 10 A toner for developing an electrostatic latent image, wherein the particles have a volume average particle diameter of 4 to 10 μm. 2. The polyester resin having an acid value of 2-3.
2. The toner for developing an electrostatic latent image according to claim 1, wherein the toner is 0 mgKOH / g. 3. The agglomerate particles have a shape factor of 120-1.
The toner for developing an electrostatic latent image according to claim 1, wherein the toner is 60. 4. The method according to claim 1, wherein the aggregate particles have a hydrophobicity of 30 or more.
^2. The electrostatic latent image developing toner according to claim 1, wherein inorganic fine particles having an ET specific surface area of 20 to 300 m ² / g are externally added. 5. The method according to claim 1, wherein the inorganic fine particles have a degree of hydrophobicity of 30 or more.
ET specific surface area of 100 to 300 m ² / g silica fine particles and BET specific surface area of 20 to 150 m ² / g with hydrophobicity of 50 or more
5. A titania fine particle comprising:
The toner for developing an electrostatic latent image according to the above. 6. A glass transition point of 58 to 70 ° C. and a softening point of 80.
To 130 ° C., a color resin solution comprising a polyester resin having a number average molecular weight of 2,000 to 10,000 and a weight average molecular weight / number average molecular weight of 2 to 10, a colorant and a water-insoluble organic solvent is emulsified and dispersed in water to obtain O / W. A colored emulsion having a volume average particle diameter of 0.1 to 1 μm is formed by forming a mold emulsion and then removing the organic solvent, and then the colored resin particles are aggregated to form a volume average particle diameter of 4 to 1 μm.
A method for producing a toner for developing an electrostatic latent image, wherein toner particles comprising 0 μm aggregate particles are obtained. 7. After the colored resin particles are formed, an aqueous solution of at least one coagulant selected from the group consisting of magnesium sulfate, aluminum sulfate, barium chloride, calcium chloride and sodium chloride is added to form the colored resin particles. The method for producing a toner for developing an electrostatic latent image according to claim 7, wherein the aggregated particles are formed by aggregating and then performing a heat treatment.