JPH11143118A - Electrostatic charge image developing toner and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner with which a high-quality image can be obtd. without causing increase in fog, decrease in image density, production of cleaning defects, decrease in transfer efficiency or irregular image even when the toner is used for a long period of time. SOLUTION: This toner is prepared by externally adding a mixture of fine powders to color particles containing at least a binder resin and a coloring agent. The mixture of fine powders consists of silica having 5 to 20 nm average primary particle size the surface of which is treated with an alkoxysilane or silazane, and at least one kind of silica or titanium oxide having 30 to 500 nm average primary particle size the surface of which is treated with a silicone oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a toner for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like, and an image forming method.

[0002]

2. Description of the Related Art In toners used for electrophotography, electrostatic recording, electrostatic printing, etc., inorganic toners are used in order to obtain good developing property, cleaning property and transfer property by adjusting the chargeability and fluidity of the toner. It is generally known to externally add fine particles and the like.

In order to obtain the above-mentioned good characteristics,
It is effective to use inorganic particles having a primary particle diameter of about 50 nm or less.

[0004] However, the toner to which such inorganic fine particles are externally added is, for example, subjected to stress with a carrier when used as a two-component developer, a developer application blade when used as a one-component developer, It has been confirmed that the toner used for a long time has a state in which inorganic fine particles are embedded in the surface due to the stress from the developer supply roller or the collision between the inner wall of the developing device, the stirring blade, and the toner.

In order to reduce the burial of the inorganic fine particles,
JP-A-4-204751, JP-A-5-34668
No. 2, JP-A-6-313980, JP-A-6-313980
As disclosed in JP-A-332235, JP-A-7-92724, etc., a method in which large-sized inorganic particles are used in combination is effective.

[0006] The addition of large-sized inorganic particles produces a so-called spacer effect, and the surface of the toner to which the inorganic fine powder has adhered forms a carrier, a developer coating blade, a developer supply roller, an inner wall of a developing unit, a stirring blade, other toners, and the like. Prevent direct contact with and reduce stress. Thereby, the burial of the inorganic fine powder is suppressed, and the life of the toner is extended.

[0007]

However, in the toner using the above-mentioned inorganic fine particles and large-diameter inorganic particles in combination, the large-diameter inorganic particles are easily released from the toner surface because of their small electrostatic adhesion. During development, when the released large-diameter inorganic particles are selectively developed, the amount of the large-diameter inorganic particles on the surface of the toner in the developing device gradually decreases, and the embedding of the inorganic fine particles on the toner surface is reduced. This causes problems such as deterioration of developability (increase in fog, decrease in image density), occurrence of cleaning failure, and decrease in transfer efficiency. Conversely, if the released large-diameter inorganic particles remain in the developing device without being developed and are concentrated, the fluidity of the toner is extremely deteriorated, and the toner coat on the developer carrier becomes uneven, Image unevenness occurs. It has been confirmed that a problem occurs when the mixing ratio between the initial inorganic fine particles and the large-diameter inorganic particles changes as described above.

Accordingly, the present invention has been made for the purpose of improving these problems. That is, the object of the present invention is to
Even when used for a long period of time, toner for electrostatic image development and image formation capable of obtaining high-quality images without increasing fog, lowering image density, causing poor cleaning, lowering transfer efficiency, and generating image unevenness. It is to provide a method.

[0009]

Means for Solving the Problems The present invention is directed to a colored particle having at least a binder resin and a colorant, silica having an average primary particle size of 5 to 20 nm and having a surface treated with alkoxysilane or silazane; The average diameter of the primary particles is 30
The present invention relates to a toner for developing an electrostatic image, wherein a fine powder mixed with at least one kind of silica or titanium oxide, the surface of which has been treated with silicone oil and having a thickness of up to 500 nm, is externally added.

Further, the present invention provides an electrostatic latent image formed on a latent image holding member using a one-component developing device having a developer applying blade and a developer supply roller in contact with a developer carrier. And an image forming method for developing the image with the toner.

As a result of investigations by the present inventor, it has been found that the mixing ratio of the inorganic fine particles and the large-sized inorganic particles in the toner using both the inorganic fine particles and the large-sized inorganic particles as the external additive changes over a long period of time. However, it has been found that it is necessary to suppress the change in the mixing ratio in order to further extend the life.

Therefore, as a result of repeated studies on inorganic fine particles and large-diameter inorganic particles to be added as external additives, the use of the above-mentioned specific mixed fine powder as an external additive makes it possible to obtain inorganic fine particles and large-diameter inorganic particles. It was concluded that the change of the mixing ratio could be suppressed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The average diameter of primary particles is 5 to 20 n.
m, preferably 5 to 15 nm, and silica whose surface is treated with alkoxysilane or silazane (hereinafter referred to as particles A) has good developing properties and cleaning properties by adjusting the chargeability and fluidity of the toner. In addition to being able to obtain transferability, it has excellent stability against temperature and humidity.

If the average particle size of the primary particles is less than 5 nm, the particles are buried in minute irregularities on the toner surface, and the chargeability and fluidity cannot be sufficiently adjusted, which is not preferable. Also, when the average particle size of the primary particles exceeds 20 nm, sufficient fluidity is not given to the toner, and the large-sized inorganic particles used together are promoted to be liberated from the toner surface, which is not preferable.

When the surface is treated with a material other than alkoxysilane or silazane (eg, chlorosilanes, silane coupling agents, titanium coupling agents, silicone oil, etc.), sufficient fluidity can be imparted to the toner. Not preferred.

As the alkoxysilane or silazane,
Methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, dimethyldiethoxysilane, isobutyltrimethoxysilane, hexamethyldisilazane and the like can be used, but isobutyltrimethoxysilane and hexamethyldisilazane are particularly preferred.

The preferred treatment amount of these alkoxysilanes or silazanes is 5 to 25 parts by weight, more preferably 10 to 20 parts by weight, per 100 parts by weight of silica.

On the other hand, the large-diameter inorganic particles have an average primary particle size of 30 to 500 nm, preferably 40 to 300 nm.
at least one kind of silica or titanium oxide (hereinafter referred to as particle B), the surface of which is treated with silicone oil in nm.
).

When the average diameter of the primary particles is less than 30 nm,
The addition of large-sized inorganic particles is not preferable because the expected spacer effect is not seen. In addition, the average diameter of the primary particles is 500 n.
If it exceeds m, release from the toner surface increases, which is not preferable.

As the large-diameter inorganic particles, silica or titanium oxide is used. When other inorganic particles such as alumina, tin oxide, zinc oxide, magnesium oxide, strontium titanate and the like are used, the particles from the surface of the toner It is not preferable because release is increased.

Further, the large-sized inorganic particles are surface-treated with silicone oil, and can be prevented from being released from the toner surface. When treated with a substance other than silicone oil (for example, alkoxysilane, silazane, coupling agent, etc.) or treated with the same treating agent as the particles A, the liberation from the toner surface increases, which is not preferable.

As the silicone oil, dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil and the like can be used.
Particularly, dimethyl silicone oil is preferable, and the viscosity of the oil at 25 ° C. is preferably 100 cSt or less.

The preferred treatment amount of the silicone oil is 2 to 20 parts by weight per 100 parts by weight of silica or titanium oxide.
More preferably, it is 5 to 15 parts by weight.

As described above, by using the mixed fine powder of the particles A and the particles B, it is possible to further extend the life of the conventionally proposed toner using both the inorganic fine particles and the large-diameter inorganic particles. Becomes

Although it is not clear why the above is achieved, it is presumed as follows.

In general, when inorganic fine particles and large-sized inorganic particles were externally added to a toner, it was observed that these particles adhered to the toner surface independently of each other. At this time, it is considered that the inorganic fine powder has a small particle size, so it is electrostatically firmly attached to the toner surface, and the large-particle inorganic powder has a large particle size, so that it is electrostatically loosely attached to the toner surface. Therefore, it can be expected that the large particle size inorganic powder is easily released from the toner surface.

On the other hand, in the present invention, it was observed that a part of the particles A independently adhered to the toner surface and a part thereof aggregated with the particles B and adhered to the toner surface. In this case, the particles B
Particle A, which forms an agglomerate with the toner, electrostatically acts as an anchor between the particle B and the toner surface.
Is considered to be hardly released from the toner surface.

As described above, the particle A has a particle size of 20%.
When the particle diameter exceeds 500 nm, when the particle B is treated with a material other than silicone oil, or when treated with the same treating agent as the particle A, the electrostatic anchor effect described above is reduced, so that the particle B is released from the toner surface. Worsens.

Here, the average diameter of the primary particles was measured using a transmission electron microscope. The shooting magnification is 150,000 times,
Further, the photographed image is stretched four times and the particle size of the primary particles is measured. At this time, the average value measured and measured with the long axis and the short axis is defined as the particle diameter. This was measured for 100 samples and 50%
The value was taken as the average particle size.

As a method for evaluating the particle diameter, measurement of the specific surface area (BET) is also common. However, regarding the particles which have been subjected to the surface treatment as in the present invention, if they are treated to the same original material, However, it has been confirmed that the specific surface area varies depending on the type of the treatment agent, the amount of the treatment agent, and the like.

Therefore, in the present invention, the evaluation of the particle size based on the specific surface area is not preferable, but as a rough guide, the particle A is 150 m ² / g or more and the particle B is 50 m ² / g or less. The specific surface area was measured according to the BET method.
Nitrogen gas was adsorbed on the sample surface using a specific surface area measuring device, Autosorb 1 (manufactured by Yuasa Ionics), and the BET multipoint method was used for calculation.

As described above, the average primary particle size is 5
Silica whose surface is treated with alkoxysilane or silazane and an average primary particle diameter of 50 to 50 nm.
By using a mixed fine powder of at least one kind of silica or titanium oxide whose surface is treated with silicone oil at 0 nm, it is possible to further extend the life of a toner using both inorganic fine particles and large-diameter inorganic particles. Although it becomes possible, when the particle size distribution of the mixed fine powder of particles A and B consists of only one peak, the life of the toner can be further extended.

Generally, when two or more types of particles having different particle sizes are mixed and the particle size distribution is measured, two or more peaks are observed. In the present invention, however, a part of the particles A and the particles B are aggregated. Therefore, the number of particles A present alone decreases, the contribution of the particle size distribution decreases, and a change appears in the shape of the particle size distribution of the mixed fine powder. Examination of the relationship between the particle size distribution of the mixed fine powder and the life of the toner to which the fine powder was externally added revealed that the life of the toner was particularly prolonged when the particle size distribution of the mixed fine powder reached one peak. Was. This indicates that the aggregate of particles A and B was sufficiently generated.

When the particle size distribution of the mixed fine powder is two peaks or more, the formation of aggregates of particles A and B is insufficient,
Slightly inferior to long life of toner.

The particle size distribution of the mixed fine powder of the present invention was measured using LS230 (manufactured by Coulter Co., Ltd.) using a method of measuring a difference in polarization scattering intensity. In this method, the particle size distribution as an aggregate is measured instead of the particle size distribution of the primary particles. Disperse the toner in ethanol,
After being subjected to an ultrasonic disperser, the external additive was separated by a centrifuge to obtain a sample. Using ethanol as solvent, PI
It was measured at a DS concentration of 45%. As parameters, the refractive index of the solvent was 1.36, the refractive index of the sample was 1.5 (real part),
0 (imaginary part), and the data was graphed by particle diameter-number%.

The amount of the particles A added to the toner is preferably from 0.3 to 2.5 parts by weight, more preferably from 0.7 to 2.0 parts by weight, per 100 parts by weight of the colored particles. The addition amount of the particles B is preferably 0.3 to 1.3 times the addition amount of the particles A to the toner, and more preferably 0.5 to 1.3 times.
~ 1.0 times.

The shape factor SF-1 of the toner of the present invention is 10
It is preferably 0 to 140. At this time, stress is uniformly applied over the entire surface of the toner.
Is more remarkably exhibited, and the life of the toner can be extended.

The shape factor SF-1 of the toner is expressed by FE-SE
M: Using a S-800 (manufactured by Hitachi, Ltd.), 100 toner images were randomly sampled from an image magnified 5000 times, and the image information of each of them was sampled via an interface into an image analyzer Luzex3 (Nicolet). And the average value of the values calculated by the following equation (1) was defined.

[0039]

(Equation 1) (Where MXLNG indicates the absolute maximum length of one toner image, and AREA indicates the projected area of one toner image)

The method for producing the colored particles of the present invention is not particularly limited. However, in order to make SF-1 100 to 140, it is produced by a suspension polymerization method, a mechanical pulverization method, a sphering treatment, or the like. And particularly preferably a suspension polymerization method.

Hereinafter, the method for producing the colored particles of the present invention in the suspension polymerization method will be described.

First, a low softening point substance is contained in a polymerizable monomer.
A polar resin, a colorant, a charge control agent, a polymerization initiator, and other additives are added, and a monomer system uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like is added to an aqueous phase containing a dispersion stabilizer. Is dispersed using a conventional stirrer, homomixer, homogenizer or the like. At this time, the agitation speed and time are preferably adjusted so that the monomer droplets have a desired size of the developer particles, and granulation is performed. Thereafter, stirring may be performed to such an extent that the state of the particles is maintained and sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization temperature is preferably set to 40 ° C. or higher, generally 50 to 90 ° C. Also, the temperature may be raised in the latter half of the polymerization reaction,
Furthermore, in order to remove unreacted polymerizable monomers, by-products, and the like that cause odor at the time of fixing the developer, in the latter half of the reaction or at the end of the reaction, even if a part of the aqueous medium is distilled off Good. After completion of the reaction, the generated developer particles are collected by washing, filtration, and dried. In the suspension polymerization method, the monomer system 1 is usually used.
It is preferable to use 300 to 3000 parts by weight of water with respect to 00 parts by weight as a dispersion medium.

The control of the particle size distribution and the particle size of the colored particles is as follows.
Methods and mechanical device conditions for changing the type and amount of the dispersant that acts as a poorly water-soluble inorganic salt or protective colloid, and stirring conditions such as the peripheral speed of the rotor, the number of passes, the shape of the stirring blade,
By controlling the shape of the container or the solid content concentration in the aqueous solution, predetermined colored particles of the present invention can be obtained.

The polymerizable monomers used in the present invention include styrene, o (m-, p-)-methylstyrene, m
Styrene-based monomers such as (p-)-ethylene styrene;
Methyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, ( (Meth) acrylate monomers such as 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylic acid Ene monomers such as amides are preferably used.

As the polar resin to be added at the time of polymerization, a copolymer of styrene (meth) acrylic acid, a maleic acid copolymer, a polyester copolymer, and an epoxy resin are preferably used.

The low-softening point substance used in the present invention includes paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax, derivatives thereof, and graft / block compounds thereof. Is preferably used.

The coloring agent used in the colored particles of the present invention includes:
As a black colorant, carbon black, a magnetic substance, and a black / white color using a yellow / magenta / cyan colorant shown below are used.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
A compound represented by an azo metal complex, a methine compound or an allylamide compound is used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168, 180 and the like are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazole compounds, thioindigo compounds and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8: 2, 48: 3, 48: 4, 57: 1, 81: 1, 1
22, 144, 146, 166, 169, 177, 18
4, 185, 202, 206, 220, 221, 254
Is particularly preferred.

As the cyan coloring agent, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 1
5: 3, 15: 4, 60, 62, 66, etc. can be particularly preferably used.

These colorants are added in an amount of about 1 to 20 parts by weight based on 100 parts by weight of the polymerizable monomer. When a magnetic material is used as a black colorant, unlike other colorants, 40 to 100 parts by weight of the polymerizable monomer is used.
Used by adding 150 parts by weight.

The charge control agents used in the present invention include:
Although a known agent can be used, a charge control agent having no polymerization inhibitory property and having no solubilized substance in an aqueous system is particularly preferable. Specific compounds include salicylic acid, naphthoic acid, dicarboxylic acids, metal compounds of their derivatives, sulfonic acids, high molecular compounds having carboxylic acids in their side chains, boron compounds, urea compounds, silicon compounds, calixarene as negative compounds. And the like, and a quaternary ammonium salt, a high molecular weight compound having the quaternary ammonium salt in a side chain, a guanidine compound, an imidazole compound and the like are preferably used. The charge control agent is preferably used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the polymerizable monomer.

Examples of the polymerization initiator used in the present invention include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutylnitrile,
1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-
Azo polymerization initiators such as dimethylvaleronitrile and azobisisobutylnitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroxy peroxide, 2,
A peroxide-based polymerization initiator such as 4-dichlorobenzoyl peroxide and lauroyl peroxide is used.

The amount of the polymerizable initiator to be added varies depending on the desired degree of polymerization, but is generally in the range of 0.5 to 0.5 per monomer.
20% by weight is used. The type of polymerization initiator is
Although it differs slightly depending on the polymerization method, it may be used alone or in combination with reference to the 10-hour half-life temperature.

As a dispersant used when utilizing suspension polymerization, for example, inorganic oxides such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, and calcium hydroxide , Magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, magnetic material, ferrite and the like. As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used by being dispersed in an aqueous phase.

It is preferable to use 0.2 to 2.0 parts by weight of these dispersants based on 100 parts by weight of the polymerizable monomer.

As these dispersants, commercially available ones may be used as they are. However, in order to obtain finely dispersed particles having a uniform particle size, the inorganic compound is formed under high-speed stirring in a dispersion medium. You can also get. For example, in the case of calcium phosphate, a dispersant suitable for a suspension polymerization method can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring.

In order to make these dispersants finer,
0.001 to 0.1 part by weight of a surfactant may be used in combination. Specifically, commercially available nonionic, anionic and cationic surfactants can be used, for example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate,
Calcium oleate and the like are preferably used.

Next, a method for producing colored particles in the pulverization method will be described.

The binder resin used for the colored particles of the present invention includes polystyrene, poly-α-methylstyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene- A vinyl acetate copolymer, a styrene-acrylate copolymer, a styrene-methacrylate acrylic copolymer, a vinyl chloride resin, a polyester resin, an epoxy resin, a phenol resin, a polyurethane resin and the like can be used alone or in combination. Among them, styrene-acryl, styrene-methacrylic copolymer resin and polyester resin are preferred.

The coloring agent used in the present invention includes:
Known materials can be used, for example, carbon black;
C. I. Pigment Red 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12, 13, 14, 15, 1,
6, 17, 18, 19, 21, 22, 23, 30, 3
1, 32, 37, 38, 39, 40, 41, 48, 4
9, 50, 51, 52, 53, 54, 55, 57, 5
8, 60, 63, 64, 68, 81, 83, 87, 8
8, 89, 90, 112, 114, 122, 123, 1
63, 202, 206, 207, 209; I. Pigment Violet 19: C.I. I. Butt Red 1,
2, 10, 13, 15, 23, 29, 35; I. Solvent red 1, 3, 8, 23, 24, 25, 27,
30, 49, 81, 82, 83, 84, 100, 10,
9, 121; I. Disperse Red 9; I.
Solvent violet 8, 13, 14, 21, 27;
C. I. Oil-soluble dyes such as Disperse Violet 1,
C. I. Basic Red 1, 2, 9, 12, 13, 1
4, 15, 17, 18, 22, 23, 24, 27, 2
9, 32, 34, 35, 36, 37, 38, 39, 4,
0; I. Basic violet 1, 3, 7, 1
Basic dyes such as 0, 14, 15, 21, 25, 26, 27, 28; I. Pigment Blue 2, 3, 15,
16, 17; I. Bat blue 6; I. Acid blue 45; I. Pigment Yellow 1, 2,
3, 4, 5, 6, 7, 10, 11, 12, 13, 14,
15, 16, 17, 23, 65, 73, 83; I.
Bat Yellow 1, 3, 20 and the like, and these can be used alone or in combination.

The amount of the colorant used is 0.1 to 60 parts by weight, preferably 0.5 to 50 parts by weight, based on 100 parts by weight of the binder resin.

When the colored particles of the present invention are controlled to be positively charged, a nigrosine dye; a modified product with a fatty acid metal salt, etc .; tributylbenzidylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium Onium salts such as quaternary ammonium salts such as tetrafluoroborate, and their analogs such as phosphonium salts, and lake pigments thereof; triphenylmethane dyes and these lake pigments (phosphotungstic acid, phosphorus Molybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.); amine and polyamine compounds; metal salts of higher fatty acids; acetylacetone metal complexes; dibutyltin oxide, dioctyltin oxide; The Black diorganotin oxides such as hexyl tin oxide; dibutyl tin borate,
A diorganotin borate such as dioctyl tin borate and dicyclohexyl tin borate is added. When controlling to negative chargeability, an organometallic complex, a chelate compound is effective and a monoazo metal complex, an acetylacetone metal complex,
An aromatic hydroxycarboxylic acid or an aromatic dicarboxylic acid-based metal complex can be used. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol. The amount used is 0.1 to 15 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the binder resin.

A release agent can be added to the colored particles of the present invention, if necessary. For example, aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, paraffin wax and Fischer-Tropsch wax or oxides thereof; waxes mainly containing fatty acid esters such as carnauba wax and montanic acid ester wax; A partially or wholly deoxidized product may be used. In addition, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brandic acid, eleostearic acid, and vinaric acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, and seryl alcohol And saturated alcohols such as sorbitol; fatty acid amides such as linoleic acid amide; saturated fatty acid bisamides such as methylenebisstearic acid amide; unsaturated fatty acid amides such as ethylenebisoleic acid amide N,
Aromatic bisamides such as N'-distearyl isophthalic acid amide; fatty acid metal salts such as zinc stearate;
Waxes obtained by grafting an aliphatic hydrocarbon wax with a vinyl monomer such as styrene; a partially esterified product of a fatty acid such as behenic acid monoglyceride and a polyhydric alcohol; a hydroxyl group obtained by hydrogenation of vegetable oil or the like A methyl esterified compound having the following formula can also be used. The addition amount is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the binder resin.
Parts by weight.

When the colored particles of the present invention are used as a magnetic toner, a magnetic material is added. For example, iron oxides such as magnetite, hematite, and ferrite; Fe, Co,
Metals such as Ni, or these metals and Al, C
o, Cu, Pb, Mg, Ni, Sn, Zn, Sb, B
Alloys with metals such as e, Bi, Cd, Ca, Mn, Se, Ti, W, V, and mixtures thereof, and the like. These magnetic materials have an average particle size of about 0.1 to 2 μm, and have magnetic properties when applied at 800 kA / m.
6 to 24 kA / m, saturation magnetization = 50 to ²⁰⁰ Am ² / k
g, residual magnetization = ^{2 to 20} Am ² / kg is preferable.

The magnetic properties were measured under an external magnetic field of 800 KA / m using a vibrating sample magnetic force meter VSM-3S-15 (manufactured by Toei Kogyo).

Next, the binder resin, release agent, charge control agent, pigment or dye as a colorant, magnetic material, and the like are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill. , Melt kneading using a heat kneader such as an extruder to disperse or dissolve the charge control agent and colorant in the resin to make them compatible with each other, and after cooling and solidifying, mechanically pulverize to the desired particle size. Further, the particle size distribution is sharpened by classification. Alternatively, a finely pulverized product obtained by colliding with a target under a jet stream after cooling and solidifying is formed into a sphere by thermal or mechanical impact.

The colored particles obtained by the above method were added to particles A
As a method for externally adding the particles A and the particles B, the coloring particles, the particles A and the particles B are added to a high-speed stirring mixer such as a Henschel mixer.
And stirring at a peripheral speed of about 20 to 50 m / s to adhere the particles A and B to the surface of the colored particles, but the following method is more preferable.

That is, the particles A and B are put into a Henschel mixer and stirred at a peripheral speed of about 30 to 50 m / s.
Thereby, an aggregate of the particles A and the particles B is generated. Colored particles are further added thereto, and the particles are stirred at a peripheral speed of about 20 to 40 m / s to adhere particles A and B to the colored particles.

The toner of the present invention exerts its effect in any image forming method, and particularly exerts its effect to the maximum in the method described below.

That is, the electrostatic latent image formed on the latent image holding member is developed by toner using a one-component developing device having a developer applying blade and a developer supply roller in contact with the developer carrier. Image forming method. The toner is fed onto the developer carrier by the developer supply roller and is thinly coated by the developer application blade, and is charged at this time. Further, the toner remaining on the developer carrier without being developed is peeled off from the developer carrier by the developer supply roller. This method enables uniform charging by thinning, so that an excellent image with less fogging can be obtained.However, compared to other developing methods, for example, the two-component developing method, the toner is subjected to a large stress, so that the toner is deteriorated. There is also a problem that the toner life is shortened quickly. Since the toner of the present invention is resistant to such stress and has a long service life, it exhibits excellent effects even when used in this developing method.

Next, the above-described developing method will be described with reference to FIG.

Reference numeral 98 denotes a latent image holding member, and a latent image is formed by an electrophotographic process means or an electrostatic recording means (not shown). Reference numeral 99 denotes a developer carrier, which is formed of a non-magnetic sleeve made of aluminum, stainless steel, or the like. The developer carrier may be a crude aluminum or stainless steel tube as it is, but the surface thereof may be uniformly roughened by spraying glass beads or the like, or may be mirror-finished or coated with a resin or the like. More preferably, it is used.

The toner 100 is stored in a hopper 101 and is supplied onto a developer carrier 99 by a developer supply roller 102. The supply roller 102 is made of a foamed material such as a polyurethane foam, abuts on the developer carrier 99, rotates in a forward or reverse direction at a relative speed other than 0, and after the toner is supplied, after the development on the developer carrier 99. The toner (undeveloped toner) is also peeled off. The toner supplied onto the developer carrier 99 is uniformly and thinly applied by the developer application blade 103. 104 is a bias power supply.

In FIG. 9, the developer application blade 103
The base on the upper side is fixed and held in the developer container, and the lower side is bent in the direction opposite to the rotation direction of the developer carrier 99 against the elasticity of the developer application blade 103. Then, the outer surface of the blade is brought into contact with an appropriate elastic pressure.

The developer coating blade 103 is preferably made of a material of a triboelectric series suitable for charging the toner to a desired polarity.

When the toner is negatively chargeable, urethane rubber, urethane resin, polyamide, nylon, and those easily charged to positive polarity are preferable. When the toner is positively chargeable, urethane rubber, urethane resin, silicone rubber, silicone resin, polyester resin, fluororesin (for example, Teflon resin), polyimide resin, and those easily charged to negative polarity are preferable. Further, conductive rubber, conductive resin, or the like may be used. When the portion contacting the developer carrying member 99 is a molded body such as a resin or rubber, metal oxides such as silica, alumina, titania, tin oxide, zirconia, and zinc oxide are included therein to adjust the chargeability of the toner. , Carbon black, and a charge control agent generally used for toner.

When the blade is required to have durability, it is preferable that a resin and a rubber are bonded to the metal elastic body so as to abut on a portion in contact with the developer carrier 99.

[0079]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. In addition, all "parts" mean parts by weight. The particle size of the toner was measured using a Coulter Multisizer II (manufactured by Coulter Inc.), and the weight-average weight-based diameter obtained from the volume distribution was determined.

Example 1 710 parts of ion-exchanged water and 0.1 mol / L of Na ₃ P were placed in a 2-liter four-necked flask equipped with a high-speed stirrer TK-Homomixer.
480 parts of an O ₄ aqueous solution was added, the rotation speed of the homomixer was adjusted to 14,000, and the mixture was heated to 62 ° C. Here, 66 parts of a 1.0 mol / liter Na ₃ PO ₄ aqueous solution was gradually added, and a minute poorly water-soluble dispersant Ca ₃ (PO ₄ ) was added.
_An aqueous medium containing ₂ was prepared.

On the other hand, the dispersoid system is as follows: 170 parts of styrene monomer 30 parts of butyl acrylate monomer I. Pigment Blue 15: 3 12 parts ・ Metal salicylic acid compound 2 parts is dispersed for 3 hours using an attritor, then the following components are added to the above mixture, and further dispersed for 2 hours with an attritor to prepare a dispersoid system. did.

25 parts of a saturated polyester 20 parts of a low softening point substance [CH ₃ (CH ₂ ) ₂₀ COO (CH ₂ ) ₂₁ CH ₃ ]

Next, 8 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator was added to the above-mentioned dispersoid system, and then added to the above-mentioned dispersion medium.
Granulated at 000 rpm for 15 minutes. Then, the high-speed stirrer was replaced with a propeller stirrer, and polymerization was performed at 50 rpm for 5 hours.
Further, the internal temperature was raised to 80 ° C., and polymerization was performed for 5 hours. After completion of the polymerization, the slurry was cooled, and dilute hydrochloric acid was added to remove the dispersant. Further, the particles were washed with water, dried and classified to obtain colored particles having a weight average diameter of 6.1 μm.

Next, inorganic fine particles (particle A-1; BET 260 m ²⁾ obtained by treating 100 parts of silica having an average primary particle diameter of 8 nm with 14 parts of hexamethyldisilazane.
/ G) 12 g, and large-grain inorganic particles (particle B-1; obtained by surface-treating 100 parts of titanium oxide having an average primary particle diameter of 270 nm with 7 parts of dimethyl silicone oil having a viscosity of 50 cSt at 25 ° C. BET 10m ² / g) 8g
At a peripheral speed of 45 with a Henschel mixer FM-10B.
The mixture was stirred at m / s for 2 minutes. 1 kg of the above colored particles
In addition, stirring was performed at a peripheral speed of 35 m / s for 3 minutes to obtain a toner.

Particles A-1 and B separated from the toner
The particle size distribution of the mixed powder of -1 became one peak as shown in FIG. 1, and the shape factor SF-1 of the toner was 120.

Further, the toner and a ferrite carrier having a surface coated with a silicone resin were mixed at a ratio of 8: 100 to prepare a two-component developer.

Color Laser Copier 7 Full Color Copier
00 (manufactured by Canon Inc.), a durability evaluation test was performed using the two-component developer as a starter and the toner as a replenisher. The evaluation method and the evaluation result will be described later.

Example 2 100 parts of polyester resin 8 parts of carbon black 5 parts of low molecular weight polypropylene 4 parts of chromium di-t-butylsalicylate complex

The above components were mixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, coarsely ground with a hammer mill, finely ground with a Kryptron (manufactured by Kawasaki Heavy Industries), and classified to obtain a weight average diameter. 7.1 μm colored particles were obtained.

Next, inorganic fine particles (particles A-2; BET1) obtained by surface-treating 100 parts of silica having an average primary particle diameter of 10 nm with 18 parts of isobutyltrimethoxysilane.
65 m ² / g) 15 g, and the average diameter of the primary particles is 200 n
m of titanium oxide having a viscosity of 50 c at 25 ° C.
Large-diameter inorganic particles obtained by surface treatment with 9 parts of St dimethyl silicone oil (particle B-2; BET 13 m ² /
g) 8 g with a Henschel mixer FM-10B
The mixture was stirred at a peripheral speed of 40 m / s for 3 minutes. Further, 1 kg of the above colored particles was added and stirred at a peripheral speed of 35 m / s for 1 minute to obtain a toner.

Particles A-2 and B separated from the toner
The particle size distribution of the mixed powder of No. -2 became one peak as shown in FIG. 2, and the shape factor SF-1 of the toner was 157.

A two-component developer was prepared using the above toner in the same manner as in Example 1, and evaluated.

<Example 3> The average diameter of primary particles was 17 nm.
100 parts of silica is isobutyltrimethoxysilane 12
Fine particles (particles A-3; B)
ET115 m ² / g) 17 g, and the average primary particle diameter is 1
Large particle size inorganic particles (particle B-3; BET) obtained by subjecting 100 parts of 00 nm titanium oxide to surface treatment at 25 ° C. with 10 parts of dimethyl silicone oil having a viscosity of 200 cSt.
15 m ² / g) and 10 g of Henschel mixer FM-
At 10B, the mixture was stirred at a peripheral speed of 45 m / s for 3 minutes. Further, 1 kg of the colored particles of Example 1 was added, and 4 kg at a peripheral speed of 30 m / s.
After stirring for minutes, a toner was obtained.

Particles A-3 and B separated from the toner
The particle size distribution of the mixed powder of Sample No.-3 became one peak as shown in FIG. 3, and the shape factor SF-1 of the toner was 120.

The durability of the toner was evaluated in the same manner as in Example 1.

<Example 4> The average diameter of primary particles was 17 nm.
Fine particles (particle A-4; BET13) obtained by subjecting 100 parts of silica to a surface treatment with 7 parts of hexamethyldisilazane.
0m ² / g) 15 g, and large-grain inorganic particles (particle B-4) obtained by surface-treating 100 parts of silica having an average primary particle diameter of 35 nm with 10 parts of dimethyl silicone oil having a viscosity of 100 cSt at 25 ° C. BET 30 m ² / g)
8 g was stirred with a Henschel mixer FM-10B at a peripheral speed of 40 m / s for 3 minutes. Further, 1 kg of the colored particles of Example 1 was added and stirred at a peripheral speed of 40 m / s for 3 minutes to obtain a toner.

Particles A-4 and B separated from the toner
The particle size distribution of the mixed powder of Sample No.-4 became one peak as shown in FIG. 4, and the shape factor SF-1 of the toner was 120.

The durability of the toner was evaluated in the same manner as in Example 1.

<Example 5> The average diameter of primary particles was 17 nm.
Fine particles (particles A-5; BE) obtained by surface treating 100 parts of silica with 23 parts of phenyltrimethoxysilane.
T75 m ² / g) 15 g, and the average primary particle diameter is 250
100 parts of titanium oxide having a viscosity of 10 at 25 ° C.
Large particle size inorganic particles (particle B-5; BET8m ²⁾ obtained by surface treatment with 7 parts of 0 cSt dimethyl silicone oil
/ G) 8 g and 1 kg of the colored particles of Example 1 were stirred with a Henschel mixer FM-10B at a peripheral speed of 40 m / s for 3 minutes to obtain a toner.

Particles A-5 and B separated from the toner
The particle size distribution of the mixed powder of −5 had two peaks as shown in FIG. 5, and the shape factor SF-1 of the toner was 120.

The durability of the toner was evaluated in the same manner as in Example 1.

Example 6 The toner of Example 1 was evaluated using a color laser printer LBP2030 (manufactured by Canon Inc.).

<Comparative Example 1> Inorganic fine particles (particle A-6; BET26) obtained by surface-treating 100 parts of silica having an average primary particle diameter of 7 nm with 12 parts of hexamethyldisilazane.
5 m ² / g) 7 g, and 100 parts of titanium oxide having an average primary particle diameter of 100 nm were converted to a viscosity of 100 cS at 25 ° C.
large particle size inorganic particles (particle B-6; BET32 m ² /
g) 5 g with a Henschel mixer FM-10B
The mixture was stirred at a peripheral speed of 45 m / s for 3 minutes. Further, 1 kg of the colored particles of Example 1 was added and stirred at a peripheral speed of 30 m / s for 4 minutes to obtain a toner.

Particles A-6 and B separated from the toner
The particle size distribution of the mixed powder of −6 had two peaks as shown in FIG. 6, and the shape factor SF-1 of the toner was 120.

The durability of the toner was evaluated in the same manner as in Example 1.

<Comparative Example 2> The average diameter of the primary particles was 30 nm.
Fine particles (particles A-7; BET5) obtained by surface-treating 100 parts of silica with 10 parts of hexamethyldisilazane.
0 m ² / g) 10 g, and the average diameter of the primary particles is 200 nm.
100 parts of titanium oxide having a viscosity of 100 c at 25 ° C.
Large particle size inorganic particles (particle B-7; BET11m ²⁾ obtained by surface treatment with 10 parts of dimethyl silicone oil of St
/ G) was stirred for 3 minutes at a peripheral speed of 45 m / s using a Henschel mixer FM-10B. Further, 1 kg of the colored particles of Example 1 was added and stirred at a peripheral speed of 30 m / s for 4 minutes to obtain a toner.

Particles A-7 and B separated from the toner
The particle size distribution of the mixed powder of −7 had two peaks as shown in FIG. 7, and the shape factor SF-1 of the toner was 120.

The durability of the toner was evaluated in the same manner as in Example 1.

<Comparative Example 3> Particle A-1 used in Example 1
And titanium oxide 100 having an average primary particle diameter of 270 nm.
Part of which is surface-treated with 7 parts of hexamethyldisilazane to obtain large-sized inorganic particles (particle B-8; BET 15 m ² / g).
8 g was stirred with a Henschel mixer FM-10B at a peripheral speed of 45 m / s for 2 minutes. Further, the colored particles
kg, and stirred at a peripheral speed of 35 m / s for 3 minutes to obtain a toner.

Particles A-1 and B separated from the toner
The particle size distribution of the mixed powder of −8 had two peaks as shown in FIG. 8, and the shape factor SF-1 of the toner was 120.

The durability of the toner was evaluated in the same manner as in Example 1.

Comparative Example 4 The toner of Comparative Example 1 was evaluated using a color laser printer LBP2030 (manufactured by Canon Inc.).

[Evaluation Method] A pattern having an image ratio of 6% (A4) is continuously printed in an environment with an image density of 25 ° C. and 60% RH. A solid black pattern is printed on the 50th, 2,000th, and 5,000th sheets, and the density of a portion 3 cm from the leading edge of the paper is measured (average of three points at the center and both ends). The density was measured with a reflection densitometer RD918 (manufactured by Macbeth).

Image Unevenness A pattern having an image ratio of 6% (A4) is continuously printed in an environment of 25 ° C. and 60% RH. On the 50th sheet, the 2,000th sheet, and the 5,000th sheet, 10 continuous solid black patterns were printed.
Measure the density of the part 15 cm from the tip with a reflection densitometer RD918.
(Average of three points at the center and both ends). Image unevenness is evaluated by calculating the density difference between these two points.

A pattern having an image ratio of 6% (A4) is continuously printed in an environment of fog density of 25 ° C. and 60% RH. 50%, 2,000th and 5,000th sheets with 2% image ratio pattern 5
After printing zero sheets, one solid white pattern is printed. The reflectance of this print and the unused paper were measured, and the difference was defined as the fog density.

[0116]

[Table 1]

[0117]

As described above, according to the present invention, the burying of the external additive caused by the stress applied to the toner is prevented, and the fog increases, the image density decreases, the cleaning failure occurs, and the transfer occurs even after a long-term use. It is possible to provide a toner capable of obtaining a high-quality image without lowering the efficiency and generating image unevenness.

[Brief description of the drawings]

FIG. 1 is a particle size distribution of an external additive in Example 1.

FIG. 2 is a particle size distribution of an external additive in Example 2.

FIG. 3 is a particle size distribution of an external additive in Example 3.

FIG. 4 is a particle size distribution of an external additive in Example 4.

FIG. 5 is a particle size distribution of an external additive in Example 5.

FIG. 6 is a particle size distribution of an external additive in Comparative Example 1.

FIG. 7 is a particle size distribution of an external additive in Comparative Example 2.

FIG. 8 is a particle size distribution of an external additive in Comparative Example 3.

FIG. 9 is a diagram illustrating an example of the developing method of the present invention.

[Description of Reference Numerals] 98 Latent image holder 99 Developer carrier 100 Toner 101 Hopper 102 Developer supply roller 103 Developer application roller 104 Bias power supply

Claims (6)

[Claims] 1. A colored particle having at least a binder resin and a coloring agent, silica having a primary particle having an average diameter of 5 to 20 nm and a surface treated with alkoxysilane or silazane, and a primary particle having an average diameter of 30 to A toner for developing an electrostatic image, wherein a fine powder mixed with at least one kind of silica or titanium oxide, the surface of which is treated with silicone oil at 500 nm, is externally added. 2. The electrostatic image developing toner according to claim 1, wherein the particle size distribution of the mixed fine powder comprises only one peak. 3. A toner having a shape factor SF-1 of 100 to 1
The toner for developing an electrostatic image according to claim 1, wherein the toner is 40. 4. An electrostatic latent image formed on a latent image holding member is developed with toner using a one-component developing device having a developer applying blade and a developer supply roller in contact with a developer carrier. In the image forming method described above, the toner comprises, at least in a colored particle having a binder resin and a colorant, silica having an average primary particle size of 5 to 20 nm and a surface treated with alkoxysilane or silazane; An image forming method, characterized by externally adding a fine powder mixed with at least one kind of silica or titanium oxide, which has an average diameter of 30 to 500 nm and whose surface is treated with silicone oil. 5. The image forming method according to claim 4, wherein the particle size distribution of the mixed fine powder comprises only one peak. 6. A toner having a shape factor SF-1 of 100 to 1
The image forming method according to claim 4, wherein the number is 40.