JP2003215855A - Two-component developer and method for developing by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-component developer having stable electrification performance against environmental changes and little deterioration in the electrification performance for a long time and to provide a method for developing by using the developer, concerning a two-component developer comprising a toner produced by a wet granulation method and a binder type carrier and to provide a development method by using the developer. <P>SOLUTION: The two-component developer comprises a toner comprising toner particles prepared by a wet granulation method and subjected to external addition treatment with hydrophobic silica fine particles and strontium titanate fine particles, and a carrier comprising an ethylenic unsaturated nitrile resin, amino modified silicone oil and magnetic powder. The developer is used for the development method. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-component developer containing a binder type carrier and toner for use in an electrophotographic copying machine or printer, and a developing method using the same.

[0002]

2. Description of the Related Art In developing an electrostatic latent image formed on an electrostatic latent image carrier such as a photoconductor in an electrophotographic copying machine or printer, a two-component developer composed of a toner and a magnetic carrier is used. The developed developing method has been put to practical use. Iron powder type, ferrite type, binder resin type and the like are widely known as the form of the carrier. Among them, the binder type carrier in which magnetic powder is dispersed in the binder resin has characteristics such as low magnetization, low specific gravity, high electric resistance and small particle size.
Further, since the degree of freedom in selection of materials and composition ratio is relatively high, it is suitable for a carrier for high image quality development. In the two-component development method, the toner and carrier are brought into contact with each other and mechanically stirred to be charged, but as they are used, the toner itself, the charge control agent for the toner, and the post-treatment agent are spent on the carrier surface, thereby charging the carrier. Since the performance is deteriorated, the toner cannot be sufficiently charged, and there are problems that the toner is scattered and image noise such as fog occurs in the image formed on the sheet. Further, since the toner charging speed becomes slow, there is a problem that fog or image density unevenness occurs when the toner is rapidly replenished. Also, in the case of a binder type carrier, although the magnetic powder is deposited on the surface to improve the charging performance, on the contrary, it is difficult to increase the hydrophobicity of a coated carrier in which iron powder or ferrite fine particles are covered with resin, and it is difficult to improve the environment resistance and resistance. There was a problem with the spent property.

As a manufacturing method capable of providing a toner having a small particle diameter and a sharp particle size distribution at low cost, a wet granulation method such as a suspension polymerization method, a dispersion polymerization method, a resin particle association method or an emulsion dispersion method is used. It has attracted attention as a method for producing a toner for high image quality development. Since such a wet granulation method does not require a pulverizing step unlike the conventional kneading and pulverizing method, it has an advantage that an offset inhibitor can be highly added to the toner and oilless fixing can be supported.

However, when a toner is manufactured by a wet granulation method, it is generally granulated in an aqueous medium, and various chemicals such as a surfactant, a dispersion stabilizer or a salting out agent are used at that time. Although the above-mentioned various chemicals and water are removed from the toner by washing and drying in the toner manufacturing process, it is difficult to completely remove them and it is possible to obtain them by the wet granulation method due to the influence of such residual components. In addition, the toner has a lower chargeability than the toner obtained by the conventional kneading and pulverization method, and has a problem that the charge stability with respect to environmental changes is poor. In the case of a two-component developer in which the wet granulated toner is combined with a carrier having a low degree of hydrophobicity, that is, a large number of hydrophilic sites on the surface, the change in charging performance with respect to environmental conditions becomes more remarkable, and It causes the above noise.

Usually, after the developing / transferring process, the toner remaining on the electrostatic latent image carrier is removed by a cleaning blade. Wet-granulated toner has a small particle size and has a round shape, so that a high-quality image can be formed, but it cannot be completely removed by a cleaning blade and remains on the electrostatic latent image carrier. However, there is a problem that noise such as fog is generated on an image.

Further, silica fine particles are externally added to the toner in order to impart fluidity, and if the silica fine particles are liberated, if the electrostatic latent image carrier is not completely cleaned, the electrostatic latent image carrier is It remains on the surface of the image carrier. After that, the development, transfer, and cleaning steps are repeated, so that the silica fine particles are embedded in the surface of the electrostatic latent image bearing member, and toner or the like is further attached to the surface as a nucleus to cause noise such as black spots (BS) in the image. Occurs.

In the production of the binder type carrier, the resin and the magnetic powder are melt-kneaded and then pulverized to form a carrier in which the magnetic powder is dispersed in the resin. When the binding property between the resin and the magnetic powder is weak, the magnetic powder liberated from the carrier during the developing process adheres to the electrostatic latent image carrier and causes noise on the image. Particularly in the case of color toner, black magnetic powder adheres to the image to cause color turbidity.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to use a two-component developer comprising a toner and a binder type carrier by a wet granulation method and the same. In the developing method, it is an object of the present invention to provide a two-component developer which has stable charging performance against environmental changes and has little deterioration in charging performance for a long period of time, and a developing method using the same.

[0009]

The present invention relates to a toner obtained by externally adding hydrophobic silica fine particles and strontium titanate fine particles to toner particles prepared by a wet granulation method, and an ethylenically unsaturated nitrile resin. The present invention relates to a two-component developer containing an amino-modified silicone oil and a carrier containing magnetic powder and a developing method using the same. The inventor of the present invention has found that a toner obtained by externally adding hydrophobic silica fine particles and strontium titanate fine particles to toner particles prepared by a wet granulation method, an ethylenically unsaturated nitrile resin, an amino-modified silicone oil, and a magnetic It has been found that a two-component developer consisting of a carrier containing powder and a two-component developer having stable charging performance against environmental changes and little deterioration in charging performance over a long period of time.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the carrier particles contain an ethylenically unsaturated nitrile resin. The ethylenically unsaturated nitrile resin is a copolymer containing at least ethylenically unsaturated nitrile as a constituent component, that is, a copolymer of an ethylenically unsaturated nitrile and a radically polymerizable organic monomer.

The ethylenically unsaturated nitrile is represented by the following general formula (1);

[0012]

[Chemical 1]

In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom or an alkyl group. Examples of the alkyl group include lower alkyl groups such as methyl, ethyl, propyl and butyl. Specifically, acrylonitrile, methacrylonitrile, and ethacrylonitrile are preferable, and acrylonitrile is particularly preferable. With acrylonitrile,
The binding property with the magnetic powder is improved, and it is possible to prevent the generation of noise on the image due to the release of the magnetic powder.

The above-mentioned ethylenically unsaturated nitrile is 40 to 90% by weight, preferably 50 to 80% by weight, based on the total copolymer components. If the amount is too large, the polymerization will be unstable when the copolymer is synthesized, and the resin obtained will be hard, making it difficult to produce a kneading / pulverizing type binder carrier. If the amount is too small, the polymerization becomes unstable and the resin itself cannot be manufactured. 2 for ethylenically unsaturated nitrile
They may be used in combination of two or more kinds, and in that case, the total amount thereof may be within the above range.

The radically polymerizable organic monomer copolymerized with the ethylenically unsaturated nitrile is represented by the following general formula (2);

[0016]

[Chemical 2]

An acrylic organic monomer represented by:

R ⁴ represents a hydrogen atom or an alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group and a butyl group, preferably a lower alkyl group such as a methyl group and an ethyl group. Among these, a hydrogen atom and a methyl group, particularly a hydrogen atom is preferable.

R ⁵ represents a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include a methyl group, an ethyl group, a propyl group and a butyl group. Of these, a methyl group and an ethyl group are preferable, and a methyl group is particularly preferable.

The above acrylic organic monomer is 10 to 60% by weight, preferably 20 to 50% by weight of the total copolymer component.
Is. If the amount is too large, the amount of ethylenically unsaturated nitrile decreases relatively, and it becomes difficult to produce the resin. on the other hand,
If it is too small, the polymerization becomes unstable and the resin itself cannot be produced. Two or more radically polymerizable organic monomers may be used in combination, and in that case, the total amount thereof may be within the above range.

In the present invention, the ethylenically unsaturated nitrile resin may further contain a rubber component. By including the rubber component, it is effective in preventing deterioration of the carrier, that is, improving the spent resistance, and further improving the durability (charging stability).

As the rubber component, butadiene, isoprene, 2,3-dimethylbutadiene, or a conjugated diene such as butadiene-acrylonitrile rubber-acrylonitrile rubber or a conjugated diene such as butadiene-styrene rubber-
Styrene rubber or the like may be included. Butadiene is particularly preferable.

When a rubber component is included, the amount thereof is 0 to 50% by weight based on the total copolymer component. Even if it is contained in an amount of more than 50% by weight, the obtained copolymer resin becomes hard and it becomes difficult to produce a binder type carrier.

The ethylenically unsaturated nitrile resin used in the present invention is the above-mentioned ethylenically unsaturated nitrile of the general formula (1) and the radical polymerizable organic monomer of the general formula (2),
If desired, it can be obtained by copolymerizing the rubber component in the presence of a radical polymerization initiator such as azobisisobutyronitrile (AIBN).

The binder type carrier in the present invention contains at least an amino-modified silicone resin.
Amino-modified silicone oil has the following general formula (3);

[0026]

[Chemical 3]

A silicone oil represented by: If silicone oil that is not amino-modified is used, the charge rising property deteriorates. Specifically, the toner charge amount does not quickly reach a desired value immediately after toner replenishment, immediately after the image forming apparatus is started, or when the B / W ratio (ratio of the image area to the image area) is high. Fog and uneven density occur in the obtained image. That is, it is impossible to suppress fog and uneven density on an image continuously from a relatively early period to a long period.

In the general formula (3), R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group or a phenyl group. As the alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group, preferably a methyl group,
The lower alkyl group of the ethyl group can be exemplified. Among these, R ⁶ , R ⁷ , and R ⁸ are preferably each independently a methyl group or a phenyl group, and particularly preferably a methyl group at the same time.

R ⁹ is-(CH ₂ ) ₃ --or-(C
_{H 2) 3 NH (CH 2} ) 2 - represents, preferably - (C
_{H 2) 3 NH (CH 2} ) 2 - it is.

X represents (CH ₃ ) ₃ SiO- or HO-, preferably (CH ₃ ) ₃ SiO-.

Y represents (CH ₃ ) ₃ Si- or H,
Preferably _{(CH 3)} 3 is Si-.

Specifically, the following general formula (4);

[0033]

[Chemical 4]

[0034] ^{(wherein, R} 9, X and Y are the same as ^R 9, X and Y in each of the above general formula (3))
An amino-modified silicone oil represented by is preferably used.

In the present invention, among the above amino-modified silicone oils, in the general formula (4), R ⁹ is — (CH ₂ ) ₃ NH (CH ₂ ) ₂ — and X is (CH ₃ ) _3.
SiO-, and Y is _{(CH 3) 3} Si- an amino-modified silicone oil is most preferably used.

The amino-modified silicone oil can be produced by a known method. For example, in the general formula (4), X is (CH ₃ ) ₃ SiO—, and Y is (CH ₃ ).
_An amino-modified silicone oil that is ₃ Si- can be produced by the following method.

First, the aminoalkylsilane (I) produced according to the following chemical reaction formula (A) or the aminoalkylsilane (I produced according to the following chemical reaction formula (B).
By hydrolysis of I), a siloxane oligomer represented by the following general formula (4-1) is obtained.

[0038]

[Chemical 5]

(In the formula, Z is a -Cl or -OCH ₃ hydrolyzable group, and Z'is -CH ₃ or -Z);

[0040]

[Chemical 6]

(In the formula, Z and Z'are the same as Z and Z'in the above chemical reaction formula (A), respectively);

[0042]

[Chemical 7]

[0043] (wherein, ^{R 9} is the same as ^{R 9} in the general formula (3)).

Then, the siloxane oligomer represented by the general formula (4-1) is reacted with a linear or cyclic dimethylsiloxane oligomer and hexamethyldisiloxane to obtain an amino-modified silicone oil (see below). Chemical reaction formula (C)).

[0045]

[Chemical 8]

[0046] (wherein, ^{R 9} is the same as ^{R 9} in the general formula (3)).

The method for measuring the amine value is as follows.
About 1 g of a sample is weighed, 20 ml of toluene is added to dissolve it, 20 ml of isopropyl alcohol and a few drops of bromophenol blue solution are added, the solution is titrated with a 1/10 N isopropyl alcohol hydrochloride solution, and the appropriate amount until the end point is read. From this appropriate amount, the amine value is calculated by the following calculation formula. In the following formula, f is a factor (titer) of a 1 / 10N isopropyl alcohol hydrochloride solution.

[0048]

[Formula 1]

Such amino-modified silicone oil is commercially available.

For example, in the general formula (4), R ⁹ is — (CH ₂ ) ₃ NH (CH ₂ ) ₂ — and X is (CH ₃ ) _3.
SiO-, and Y is _{(CH 3)} 3 Si- an amino-modified silicone oil which is available under the trade name "SF8417" (manufactured by Dow Corning Toray Silicone Co., Ltd.).

Further, for example, in the general formula (4), R ⁹ is — (CH ₂ ) ₃ NH (CH ₂ ) ₂ — and X is HO.
-, And the amino-modified silicone oil in which Y is H is a trade name "BY16-892" (Toray Dow Corning
Available from Silicone Co., Ltd.).

For example, in the general formula (4), R
⁹Is-(CH_Two)_Three-, X is (CH _Three)_ThreeSiO-
And Y is (CH_Three)_ThreeAmino-modified silico that is Si-
Oil is trade name "BY16-897" (Toray Dauko
Available from Corning Silicone).

For example, in the above general formula (4), R
⁹ _{- (CH 2) 3 -,} X is HO-, and amino-modified silicone oil Y is H trade name "BY16-8
98 "(manufactured by Toray Dow Corning Silicone Co., Ltd.). The content of the amino-modified silicone oil may be 1 to 75 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the ethylenically unsaturated nitrile resin. If the amount of amino-modified silicone oil is too small, the effects of imparting hydrophobicity and spent resistance cannot be obtained and the durability of the carrier deteriorates. On the other hand, if the amount is too large, the binding property between the binder resin and the magnetic material is deteriorated, and image noise such as color turbidity occurs.

In the carrier of the present invention, the charge of the carrier can be adjusted by containing the amino group-containing acrylic resin and / or the amino group-containing polyether. By including the amino group-containing resin, the charge level is increased, and the charge rising property and charge stability are further improved.

The amino group-containing acrylic resin has the following general formula (11):

[0056]

[Chemical 9]

It is a copolymer of an amino group-containing monomer represented by and a radical polymerizable monomer. In the above formula, R
²⁰ represents a hydrogen atom, a lower alkyl group such as a methyl group or an ethyl group. R ²⁰ is preferably a methyl group. R ²¹
And R ²² are each independently a methyl group, an ethyl group,
It represents a lower alkyl group such as a propyl group. R ²¹ and R
Methyl group is preferably a ^{2 2.} n is an integer of 1 to 5, preferably 2.

Examples of the radically polymerizable monomer include styrene-based monomers such as styrene and styrene derivatives, and acrylic-based monomers such as alkyl acrylates and alkyl methacrylates. Examples of the alkyl acrylate include butyl acrylate, and examples of the alkyl methacrylate include butyl methacrylate and methyl methacrylate. Also,
It is preferable to use a styrene-based monomer and an acrylic-based monomer in combination as the radically polymerizable monomer.

The amino group-containing acrylic resin is prepared by combining the amino group-containing monomer represented by the general formula (11) and the radical polymerizable monomer with azobisisobutyronitrile (AI).
It can be obtained by copolymerizing in the presence of a radical polymerization initiator such as BN). At that time, the finally obtained amino group-containing acrylic resin has an amine value described later,
It is desirable to adjust the copolymerization ratio and the degree of polymerization so as to have a softening point (Tm) and a glass transition point (Tg). The content of the amino group-containing acrylic resin is 1 to 43 parts by weight, preferably 5 to 5 parts by weight based on 100 parts by weight of the total weight of the ethylenically unsaturated nitrile resin and the amino-modified silicone oil.
25 parts by weight is desirable.

The amino group-containing polyether is a polymer in which an amino group is introduced into the main chain and / or side chain of a known polyether. Particularly in the present invention, alkylene oxides such as ethylene oxide, propylene oxide, 1,2-butylene oxide, styrene oxide, glycidol and the like; dihydric alcohols such as ethylene glycol, 1,2-propanediol,
1,3-propanediol, 1,3-butanediol,
1,4-butanediol and the like; and polyhydric alcohols,
For example, a polyether obtained by introducing an amino group into a polyether obtained from glycerin, pentaerythritol or the like as a raw material is preferably used. More preferably, an amino group is introduced into a polyether consisting of the above alkylene oxides and / or the above polyhydric alcohols, and further preferably an amino group is introduced into a polyether consisting of ethylene oxide or propylene oxide. Stuff used.

The method of introducing the amino group is not particularly limited as long as a polyether having an amino group or an amino group-containing group can be obtained. For example, an amino group can be introduced into polyethylene oxide by reacting diglycidyl ether of polyethylene oxide with dimethylaminoethyl methacrylate. Further, for example, an amino group can be introduced into polyglycerin by reacting a polyepoxide of polyglycerin with acrylic acid and trimethylamine.

The amino group-containing resin used in the present invention has an amine value of 0.3 to 40 KOHmg / g and a Tg of 5.
It is preferable that the temperature is 0 to 80 ° C and the Tm is 100 to 140 ° C. Particularly, the amino group-containing acrylic resin has an amine value of 0.5 to 36 KOHmg / g, a Tg of 65 to 75 ° C., and a T
More preferably, m is 125 to 135 ° C. Further, the amine group-containing polyether has an amine value of 2 to 20K.
OHmg / g, Tg 55-65 ° C, Tm 105-1
It is more preferably 35 ° C. If the amine value is too small, the contribution to the improvement of the charge rising property becomes small, and the fog after blackening becomes worse. If it is too high, there is no difference in the contribution of the charge rising property, and there is a problem that the amount of charge becomes too high and the image density after blank paper becomes low. The decrease in image density after blank paper is a phenomenon that occurs when the toner is sufficiently charged and the charge level is too high, so that it is difficult to separate from the carrier and the developability deteriorates. The content of the amino group-containing polyether may be 0.5 to 29 parts by weight, preferably 1 to 14 parts by weight, based on 100 parts by weight of the total weight of the ethylenically unsaturated nitrile resin and the amino-modified silicone oil.

Known magnetic particles conventionally used in the field of carriers can be used as the magnetic particles, and examples thereof include ferrite, magnetite, and iron powder. Magnetite is particularly preferable. In the present invention, the average primary particle size is 100 to 1000 nm, preferably 200 to
It is desirable to use magnetic particles of 500 nm.

The amount of magnetic particles used in the carrier of the present invention is 200 to 700 parts by weight, preferably 200 to 600 parts by weight, more preferably 300 to 500 parts by weight, based on 100 parts by weight of the ethylenically unsaturated nitrile resin. Is. Further, the carrier of the present invention may optionally contain known carbon black, inorganic fine particles and the like. The binder type carrier of the present invention may be manufactured by any known method. For example, the above ethylenically unsaturated nitrile resin, amino-modified silicone oil and a magnetic material, and optionally an amino group-containing resin, carbon black, additives such as inorganic fine particles are sufficiently mixed,
After melt-kneading, coarse pulverization and fine pulverization are performed, and if desired, classification can be performed. After classification, the obtained carrier is preferably subjected to heat treatment by a surface reforming device such as a suffusing system. By carrying out the heat treatment, the carrier particle shape can be made spherical and the particle surface can be controlled to be smooth. Therefore, uniform charging performance and spent resistance to the toner can be obtained, and as a result, the charge rising property and the charge stability are improved. Further improve. Furthermore, ultrafine powder, free magnetic powder, and the like can be fixed to the surface, and image noise caused by these can be reduced. In the present invention, the inclusion of the amino-modified silicone oil makes it possible to impart hydrophobicity to the carrier and improve environmental stability. In order to have sufficient hydrophobicity to maintain environmental stability, the following conditions may be satisfied. That is, when the carrier is poured into water, the amount of the carrier floating on the liquid surface is 50% of the total amount.
˜90 wt%, preferably 65 to 85 wt%, more preferably 70 to 80 wt%. If the ratio of the amount of suspended particles is less than 50% by weight, it indicates that the carrier has low hydrophobicity, that is, high hydrophilicity, and the environment resistance and the spent resistance of the charging performance deteriorate. On the other hand, if the ratio of the amount of suspended particles is more than 90% by weight, the fluidity of the carrier becomes too high, which results in a failure in charging start-up.
Furthermore, when the carrier is charged in a 1: 1 mixed solvent of water and methanol, the amount of the carrier floating on the liquid surface is 10% by weight or more, preferably 15% by weight or more, more preferably 20% by weight of the total amount charged. When it is at least%, it can be regarded as having sufficient hydrophobicity to obtain sufficient environmental stability. When the ratio of the amount of suspended particles is less than 10% by weight, the carrier surface does not have sufficient hydrophobicity, and the environment resistance and spent resistance of the charging performance deteriorate.

The toner of the present invention comprises toner particles obtained by a wet granulation method and an external additive externally added to the toner particles. In the present specification, the “external additive” refers to fine particles added in advance so as to be present outside (surface) of toner particles obtained by a wet granulation method. As the toner particles, toner particles produced by a wet granulation method such as a suspension polymerization method, a dispersion polymerization method, a resin particle association method or an emulsion dispersion method are used. By manufacturing the toner particles by such a method, it becomes possible to provide the toner particles having a smaller particle size and a sharp particle size distribution as compared with the pulverization method at a low cost. Among the wet granulation methods, the suspension polymerization method and the resin particle association method are preferable, and the resin particle association method is particularly preferable from the viewpoint of the degree of freedom in controlling the shape of toner particles.

In the resin particle association method, particles in a particle dispersion liquid in which particles containing at least resin particles are dispersed are aggregated (salted out), and the obtained aggregated particles are heated and fused to produce toner particles. Is the way to do it. At the time of aggregation, a method of mixing with a colorant that is a toner constituent component, if necessary, an offset prevention agent, a charge control agent, or the like to be mixed and agglomerated, or a colorant or an offset in a monomer that constitutes the resin particles Examples thereof include a method in which a toner constituent component such as an inhibitor is dispersed and then emulsion polymerization is performed. Preferably, the resin particles, the colorant particles and the offset preventing agent particles are aggregated and fused in an aqueous medium. The resin particles have a weight average particle diameter of 50 to 2000 nm.
It is preferable to use those of For this reason, it is preferable that the resin particles are prepared by an emulsion polymerization method in which fine particles are obtained.

Aggregation (salting out) and fusion of particles containing at least resin particles can be carried out by any of a method of forming aggregated primary particles and then performing fusion, and a method of advancing aggregation (salting out) and performing fusion at the same time. Good. In the case of the latter, for example, at least resin particles, colorant particles and offset inhibitor particles are added to the salting out agent having an alkali metal salt or an alkaline earth metal salt in water in which the particles are dispersed, the critical coagulation concentration or more, then the resin particles By heating above the glass transition point of (1), salting out proceeds and at the same time fusion is performed. At this time, a method may be used in which an organic solvent that is infinitely soluble in water is added to substantially lower the glass transition temperature of the resin particles to effectively perform the fusion.

Examples of the alkali metal atom of the salting-out agent, ie, the alkali metal salt and the alkaline earth metal salt, include metal atoms such as lithium, potassium, and sodium, and the alkaline earth metal atom includes magnesium, calcium, strontium, Examples include metal atoms such as barium. Of these, metal atoms such as potassium, sodium, magnesium, calcium and barium are preferable. Examples of the salt of the alkali metal salt and the alkaline earth metal salt include chlorine salt, bromine salt, iodine salt, carbonate salt, and sulfate salt. As the organic solvent infinitely soluble in water, for example, methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, glycerin, acetone and the like can be mentioned, but preferably methanol, ethanol, 1-propanol having 3 or less carbon atoms, The alcohol of 2-propanol is more preferable, and 2-propanol is more preferable.

The temperature at which the salting-out agent is added needs to be at least not higher than the glass transition temperature of the resin particles. The reason for this is that if the temperature at which the salting-out agent is added is equal to or higher than the glass transition temperature of the resin particles, salting-out / fusion of the resin particles will proceed rapidly, but it will be difficult to control the particle size and There arises a problem that particles having a particle size are generated. The range of this addition temperature may be not higher than the glass transition temperature of the resin particles, but is generally 5 to 55 ° C, preferably 10 to 45 ° C. Further, it is preferable to add a salting-out agent at a temperature not higher than the glass transition temperature of the resin particles, then raise the temperature as quickly as possible and then heat the resin particles to a temperature not lower than the glass transition temperature.

The resin particles are preferably resin particles prepared by emulsion polymerization. As the polymerizable monomer for preparing the resin particles, a radical polymerizable monomer is an essential constituent component, and a crosslinking agent can be used if necessary. Further, the following radical-polymerizable monomer having an acidic group or radical-polymerizable monomer having a basic group may be contained.

The radical polymerizable monomer is not particularly limited, and conventionally known radical polymerizable monomers can be used. For example, an aromatic vinyl monomer,
Acrylic ester-based monomer, methacrylic acid ester-based monomer, vinyl ester-based monomer, vinyl ether-based monomer, monoolefin-based monomer, diolefin-based monomer, halogenated olefin-based monomer Etc. can be used.

As the aromatic vinyl monomer, for example,
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- Examples thereof include styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

Examples of acrylic acid ester monomers include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate,
Examples include β-hydroxyacrylate and γ-aminopropyl acrylate. Examples of the methacrylic acid ester-based monomer include methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate,
Examples include stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

The vinyl ester-based monomer is vinyl acetate, vinyl propionate, vinyl benzoate, etc., and the vinyl ether-based monomer is, for example, vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether. And the like, as the monoolefin-based monomer, for example, ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-
1-Pentene and the like, diolefin-based monomers such as butadiene, isoprene and chloroprene, and halogenated olefin-based monomers such as
Examples thereof include vinyl chloride, vinylidene chloride and vinyl bromide.

Further, a radical-polymerizable cross-linking agent may be used as a cross-linking agent in order to improve the characteristics of the resin particles. Examples of the radical-polymerizable cross-linking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diaryl phthalate. The radical-polymerizable cross-linking agent is 0.1 to 10 relative to 100 parts by weight of all radical-polymerizable monomers.
It is preferably used in the range of parts by weight.

As the radically polymerizable monomer having an acidic group, for example, a carboxyl group- or sulfone group-containing monomer can be used.

Examples of the carboxylic acid group-containing monomer include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monooctyl ester, and sulfonic acid. Examples of the contained monomer include styrenesulfonic acid, arylsulfosuccinic acid, and octyl arylsulfosuccinate. These may have a structure of an alkali metal salt such as sodium or potassium, or an alkaline earth metal salt such as calcium.

As the radical polymerizable monomer having a basic group, for example, amine compounds such as primary amine, secondary amine, tertiary amine and quaternary ammonium salt can be used. .

Examples of amine compounds include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts of the above-mentioned four compounds, 3-dimethylaminophenyl acrylate, and 2-hydroxy-. 3-methacryloxypropyl trimethyl ammonium salt, acrylamide, N
-Butyl acrylamide, N, N-dibutyl acrylamide, piperidyl acrylamide, methacrylamide,
N-butyl methacrylamide, N-octadecyl acrylamide, vinyl pyridine, vinyl pyrrolidone, vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diarylmethylammonium chloride, N, N-diarylethylammonium chloride, etc. Can be mentioned.

The radical polymerization initiator used for emulsion polymerization can be appropriately used as long as it is water-soluble. For example, a persulfate such as potassium persulfate or ammonium persulfate, an azo compound such as 4,4′-azobis-4-cyanovaleric acid and a salt thereof, or a 2,2′-azobis (2-amidinopropane) salt, or a peroxide compound. Etc. Furthermore, the radical polymerization initiator may be combined with a reducing agent to form a redox initiator, if necessary. By using the redox type initiator, the polymerization activity can be increased, the polymerization temperature can be lowered, and the polymerization time can be expected to be further shortened.

As the polymerization temperature, any temperature may be selected as long as it is at least the minimum radical formation temperature of the polymerization initiator.
The range of to 90 ° C is preferable. However, it is also possible to carry out the polymerization at room temperature or higher by using a combination of a polymerization initiator started at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid, etc.).

A surfactant is preferably used for the emulsion polymerization of the radically polymerizable monomer. The surfactant that can be used in this case is not particularly limited, but the following anionic or nonionic surfactants can be mentioned as preferred ones.

Examples of anionic surfactants include:
Sulfonate sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, etc., sulfate ester sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc. fatty acid salt sodium oleate, sodium laurate , Sodium caprate, sodium caprylate, sodium caproate,
Examples thereof include potassium stearate and calcium oleate.

Examples of the nonionic surfactant include polyethylene oxide, polypropylene oxide, combinations of polyethylene oxide and polypropylene oxide, alkylphenol polyethylene oxide, esters of higher fatty acids and polyethylene glycols, esters of higher fatty acids and polypropylene oxide, sorbitan. Esters and the like can be mentioned.

As the colorant, it is preferable to use an inorganic pigment or an organic pigment. Examples of the inorganic pigment include conventionally known black pigments. As the black pigment, for example, carbon black such as furnace black, channel black, acetylene black, thermal black and lamp black, and magnetic pigment such as magnetite and ferrite can be used. These inorganic pigments can be used alone or in combination of two or more as desired. The amount of the inorganic pigment added is preferably 2 to 20 parts by weight, more preferably 3 to 15 parts by weight, based on 100 parts by weight of the toner particles. In the case of black toner, it can be used as a magnetic toner.
Known magnetic pigments can be added. In the case of a magnetic toner, from the viewpoint of imparting magnetic properties, the toner particles 10
It is preferable to add 20 to 60 parts by weight of the magnetic pigment to 0 parts by weight.

Conventionally known organic pigments can be used as the organic pigment. Although any organic pigment can be used, specific organic pigments are listed below.

Examples of magenta or red pigments include C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I.
I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 5
7: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 13
9, C.I. I. Pigment Red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166,
C. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222 and the like. Examples of pigments for orange or yellow include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 1
2, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15,
C. I. Pigment Yellow 17, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 93, C.I.
I. Pigment Yellow 94, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 180 and the like.

Examples of cyan or green pigments include C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15:
3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

These organic pigments can be used alone or in combination of two or more as desired. The amount of the pigment added is preferably 2 to 20 parts by weight, and more preferably 3 to 15 parts by weight, based on 100 parts of the toner particles.

Colorant surface modifiers can also be used to modify the surface of the colorant. As the surface modifier of the colorant, a conventionally known one can be used. Specifically, silane coupling agent, titanium coupling agent,
Aluminum coupling agents and the like can be preferably used. Examples of the offset preventing agent include polyethylene wax, acid-modified polyethylene wax (oxidized polyethylene wax), polypropylene wax, acid-modified polypropylene wax (oxidized polypropylene wax), paraffin wax, microcrystalline wax, and carna. Uva wax, fatty acid ester wax and the like can be mentioned.

Offset-preventing agent particles can be added by various methods such as a method of adding resin particles at the stage of emulsion polymerization, a method of adding resin particles at the same time in an aggregation (salting out) step, a method of adding them directly to the finished toner. It can be added.
As a preferable method, a method of adding an offset preventive agent at the stage of emulsion polymerizing the resin particles, and a method of adding an offset preventive agent at the same time as the resin particles in the aggregation (salting out) step and incorporating them in the toner Is mentioned.

In addition to the above-mentioned colorant and offset preventive agent, additives capable of imparting various functions may be added as a toner composition. Specific examples include charge control agents.

These additives can be added by various methods such as a method of adding the resin particles at the stage of emulsion polymerization, a method of adding the resin particles at the same time in the aggregation (salting out) step, and a method of directly adding to the finished toner. It can be added. Preferred methods include a method of adding an additive in the step of emulsion polymerizing the resin particles, and a method of adding an additive simultaneously with the resin particles and the like in the aggregation (salting out) step and incorporating them in the toner. To be

The charge control agent used as an additive is a known material, and it is preferable to use a material which can be dispersed in water. Specific examples include naphthenic acid or higher fatty acid metal salts, azo metal complexes, salicylic acid metal salts, or metal complexes thereof. The charge control agent preferably has a number average primary particle diameter in a dispersed state of about 10 to 500 nm.

In the present invention, it is preferable to use a charge control agent-less toner containing no charge control agent from the viewpoints of environmental friendliness and cost reduction of the toner.

Toner particles in the aqueous medium obtained in the fusion step are filtered and washed with washing water to remove impurities such as surfactants and salting-out agents adhering to the toner particles. The filtering and washing machines used in this step are not particularly limited, but, for example, a centrifuge, Nutsche, filter press, etc. are used.

The toner particles after filtration and washing are dried.
The dryer used in this step is not particularly limited, for example, spray dryer, vacuum dryer, vacuum dryer, stationary shelf dryer, mobile shelf dryer, fluidized bed dryer, rotary dryer, stirring. A dryer is used. The amount of water in 100 parts by weight of the dried toner particles is preferably 5 parts by weight or less, more preferably 2 parts by weight or less. The preferable range of the volume average particle diameter of the toner particles is 3.0 to 8.0 μm,
Preferably 4-7.5 μm, more preferably 4.5-
It is 7.0 μm. Volume average particle diameter of toner particles is 3 μm
If it is smaller, the durability of the carrier is lowered, and the toner adheres to the carrier more frequently. Alternatively, if the volume average particle diameter of the toner particles is larger than 8 μm, the stability of the carry amount becomes low,
It causes image noise.

As described above, a toner is obtained by externally adding an external additive to the toner particles obtained by the wet granulation method.

As the external additive, hydrophobic silica having an average primary particle diameter of 5 to 50 nm is used. This makes it possible to impart desired fluidity and improve negative chargeability. Further, it is possible to improve the image quality of the image, especially the texture of the halftone image. Hydrophobic silica average 1
When the secondary particle size is smaller than 5 nm, the first hydrophobic silica is embedded in the toner particles due to the stirring stress of the developer, and the fluidity is significantly reduced. If the average primary particle size of the hydrophobic silica is larger than 50 nm, the effect of improving fluidity cannot be obtained. As the hydrophobic silica, for example, TS530 (manufactured by Cabot), R972, R974, R976 (manufactured by Nippon Aerosil Co., Ltd.), H2000, H2000 / 4M (manufactured by Clariant), or silane coupling to RX50, # 70, and # 90. A processed product is preferably used. Furthermore, silica having a desired particle size may be hydrophobized with a known silane coupling agent, silicone oil, or the like. When strontium titanate is used as the second external additive, the spent substance on the carrier can be removed due to its polishing effect.
When the toner is negatively charged and is used as a two-component developer, the use of strontium titanate, which has a weak positive charge, improves the spacer action between the toner and the carrier, and also improves the effect of the component to the carrier. Carrier deterioration due to spent is suppressed, and excellent charge rising property is obtained. Further, when a strontium titanate forms a stationary layer of the component in the gap between the photoconductor and the cleaning blade, particles of other components are prevented from slipping through, especially on the copy image due to the fixation of the hydrophobic silica. BS can be suppressed. Further, the component functions as a spacer between the toners, and the transferability is improved. It also enables appropriate photoconductor polishing. The average primary particle size of strontium titanate is 80 to 1200 nm, preferably 80.
˜1000 nm, more preferably 100 to 800 nm is desirable. If the particle size is smaller than 80 nm, the component is less likely to be accumulated in the gap between the cleaning blade and the photoconductor, is likely to slip through, and is difficult to form a stationary layer well. If the particle size is larger than 1200 nm, the photoreceptor cannot be uniformly polished, which is not preferable. The amount of strontium titanate added is 0.4 to 100 parts by weight of the toner mother particles.
The amount is 3.5 parts by weight, preferably 0.5 to 3.0 parts by weight, more preferably 1.0 to 3.0 parts by weight. Addition amount is 0.
If the amount is less than 4 parts by weight, the stationary layer cannot be formed on the blade. If the amount added is more than 3.5 parts by weight, the abrasiveness becomes too strong and the life of the photoreceptor is shortened. In addition, external stability of the toner can be improved by externally adding hydrophobic titanium oxide having an average primary particle diameter of 10 to 40 nm to the toner particles. It is possible to solve the problem without the problem of toner charge down at high humidity. The average primary particle diameter of the hydrophobic titanium oxide is preferably 15 to 35 nm, and 15 to 3 nm.
0 nm is more preferable. Further, the hydrophobicity of the hydrophobic titanium oxide is 50% or more, preferably 60 to 80%.

The amount of the hydrophobic titanium oxide added is 0.1 to 2 parts by weight, preferably 0.2 to 1.5 parts by weight, more preferably 0.3 to 1.0, based on 100 parts by weight of the toner particles.
Parts by weight.

In the present invention, a known method can be used as a developing method using a two-component developer containing a binder type carrier and a toner.

FIG. 2 shows an example of the developing device (10) used for carrying out the developing method according to the embodiment of the present invention.

In the developing device (10) shown in FIG.
A developer (1) containing a toner T and a carrier is housed therein, and a plurality of magnetic poles N ₁ , S ₁ , N ₂ , S ₂ are used as a developer carrier for carrying the developer (1). , N
₃ using a magnet roller (11a) is a cylindrical developing sleeve provided on the inner circumferential side (11) having a developing sleeve (11) is an electrostatic latent image bearing member in the developing area photoreceptor (2 ) And is rotatably held so as to face each other with an appropriate distance (Ds).

Then, the developing sleeve (11) and the photoconductor (2) are in the opposite direction, that is, in the developing area where the developing sleeve (11) and the photoconductor (2) face each other. 2) is rotated so as to move in the same direction, and the developer (1) contained in the developing device (10) is rotated by the magnet roller (11a) as the developing sleeve (11) rotates. The magnetic brush is used to convey the magnetic brush to the photoconductor (2) side.

Further, the magnetic pole N ₁ of the magnet roller (11a) is provided on the upstream side of the developing area in which the developing sleeve (11) and the photoconductor (2) face each other in the conveying direction of the developer (1). A regulating member (13) for regulating the amount of the developer (1) on the developing sleeve (11) is provided at the opposing position.
The magnetic blade (13a) as the developing sleeve (1
The magnetic blade (13a) regulates the amount of the developer (1) on the developing sleeve (11).

In the developing device (10),
Toner container (14) containing toner T on the upper part
The developing sleeve (11) to the developer (1)
The toner T in the inside is supplied to the photoconductor (2) to perform development.
As a result, in the developer (1) in the developing device (10)
If the toner density of the
The toner T stored in (14) is placed in the developing device (10).
The developer (1) is replenished. This development
As a developing method using the apparatus (10), a developing sleeve
(11) The magnetic brush formed by the developer above feels
Non-contact developing method for developing without contacting the photoconductor (2)
Expressions can be used. In this case, the above development three
Connect the developing bias power source (12) to the hub (11)
From the developing bias power source (12)
Applies a developing bias in which a DC voltage is superimposed on an AC power supply
The oscillating electric field is applied to the developing area.
It On the developing sleeve (11) in the non-contact developing method
3 to 15mg / cm^Two, Preferably
Is 5-10 mg / cm^TwoWill give you a stable image.
You can Conveying amount of developer (1) is 3 mg / cm^TwoYo
If it is set too low, the amount of developer conveyed to the developing section will be small,
Image density becomes low, 15mg / cm^TwoHigher
Noise such as fog occurs because the amount of developer is too large. Non-contact
In the touch development method, a suitable range of the volume average particle diameter of the carrier is
The envelope is 20 to 40 μm, preferably 25 to 35 μm
Is. If it is smaller than 20 μm, mixing and stirring property with toner
Deteriorates, and fogging occurs due to poor charging. Also,
If it is larger than 40 μm, the ears of the magnetic brush will become hard and
Image quality is poor. In addition to the above development method,
Magnetic block formed by the developer on the sleeve (11)
Contact development that develops while the brush contacts the photoconductor (2).
An image method can also be used. In this case, the developing sleeve
The voltage from the developing bias power supply (12) is applied to (11).
When applied, the developing sleeve (11) and the photoconductor (2) face each other.
Apply a DC or oscillating electric field to the developing area
Develop. Furthermore, the volume of the carrier in this developing method
The preferred range of the average particle size is 40 to 70 μm, preferably 50.
˜65 μm. Volume average particle size of carrier is 40μ
When it is smaller than m, the magnetic force per carrier grain decreases.
Therefore, the carrier adheres to the electrostatic latent image carrier, and
It is transferred on top and noise is generated. Also, the volume of the carrier
When the average particle size is larger than 70 μm, the carrier specific surface area is
Since it greatly decreases, the carrier life decreases. Well
Also, the saturation magnetization of the carrier is 50 to 65 Am.^Two/ G, preferred
53-63 Am ^Two/ G should be set. Saturation magnetization
50 Am^Two/ G is less than the carrier is electrostatic latent image carrier
It adheres to the top and is transferred to the image, which causes noise.
It Also, the saturation magnetization is 65 Am^Two/ G is greater than development
Soft brush of magnetic brush with developer on agent carrier
Difficult to form. Transporting the developer on the developer carrier
Delivery rate is 40-80mg / cm^Two, Preferably 45-70
mg / cm^TwoAnd Transport amount is 40 mg / cm^TwoLess than
If this is not the case, the image density during development will be low. Also, 80 mg /
cm^TwoIf it is larger than the electrostatic latent image carrier and the developer carrier,
Development unevenness occurs due to clogging of the developer between them. Book
The invention will be described in more detail by the following examples.
The invention is not limited to these examples.

[0107]

[Example] (Preparation of fine resin particle dispersion) Styrene 315
By weight, 85 parts by weight of n-butyl acrylate, 6 parts by weight of acrylic acid and 10 parts by weight of dodecanethiol were mixed and dissolved to prepare a solution. On the other hand, 6 parts by weight of a nonionic surfactant (Nonipol 400: manufactured by Kao) and an anionic surfactant (Neogen SC: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 10
50 parts by weight of ion-exchanged water is dissolved in 550 parts by weight of ion-exchanged water, and the solution is added thereto to disperse and emulsify in a flask and slowly stirred and mixed for 10 minutes while deionized water of 4 parts by weight ammonium persulfate is dissolved. Part by weight was added. Then, after thoroughly replacing the inside of the system with nitrogen, the flask was heated to 70 ° C. in an oil bath while stirring, and the emulsion polymerization was continued for 5 hours to obtain a resin having a center diameter of 171 nm, a glass transition point of 54 ° C., and a Mw of 34300. An anionic resin fine particle dispersion liquid containing fine particles was obtained. (Preparation of colorant dispersion) C.I. I. Pigment Blue 15
-3 (cyan pigment) 50 parts by weight, nonionic surfactant (Nonipol 400: manufactured by Kao Corporation) 5 parts by weight, and ion-exchanged water are homogenized (Ultra Turrax: IKA).
For 10 minutes to obtain a cyan colorant dispersion containing cyan pigment particles. (Preparation of offset preventing agent dispersion) 50 parts by weight of paraffin wax (HNP0190: manufactured by Nippon Seiro Co., Ltd.), 5 parts by weight of a cationic surfactant (Sanisol B50: manufactured by Kao Co.) and 200 parts by weight of ion-exchanged water at 95 ° C. Heat to a homogenizer (Ultra Turrax T50: IK
(Manufactured by Company A), and then sufficiently dispersed by a pressure discharge homogenizer to obtain an offset inhibitor dispersion containing release agent particles having a center diameter of 180 nm. (Preparation of Toner Particles) 200 parts by weight of fine resin particle dispersion,
40 parts by weight of the cyan colorant dispersion, 50 parts by weight of the anti-offset agent dispersion and 1.23 parts by weight of polyaluminum chloride were thoroughly mixed in a round stainless steel flask with a homogenizer (Ultra Turrax T50: manufactured by IKA).
After the dispersion, the aggregation temperature was heated to 52 ° C. while stirring the flask in a heating oil bath. Then 6 at 52 ° C
After holding for 0 minutes, 60 parts by weight of a resin fine particle dispersion was further added and gently stirred.

Then, the pH of the system was adjusted to 6.0 with a 0.5 mol / L sodium hydroxide aqueous solution, the stainless steel flask was closed, and the mixture was heated to 97 ° C. while continuing stirring with a magnetic seal. Then, the pH of the system is adjusted to 4.
It was held at 0 for 6 hours. After the reaction was completed, the reaction mixture was cooled, filtered, washed sufficiently with ion-exchanged water, and then solid-liquid separated by Nutsche suction filtration. Furthermore, it was dispersed again in 3 L of ion-exchanged water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. After repeating this washing operation 5 times, solid-liquid separation was performed by Nutsche suction filtration. Then, vacuum drying was continued for 12 hours to obtain toner particles having a volume average particle diameter of 6 μm. Post-Treatment of Toner To 100 parts by weight of the toner particles obtained as in the above production example, 0.7 parts by weight of hydrophobic silica and 0.5 part by weight of hydrophobic titanium oxide were added to a Henschel mixer (manufactured by Mitsui Mining & Smelting Co., Ltd.).
Was subjected to a surface treatment at a speed of 40 m / s for 3 minutes and externally added. The hydrophobic silica used here has an average primary particle size of 1
6 nm silica (# 130; manufactured by Nippon Aerosil Co., Ltd.) is surface-treated with hexamethyldisilazane (HMDS) which is a hydrophobizing agent. The hydrophobic titanium oxide is obtained by subjecting anatase type titanium oxide having an average primary particle diameter of 30 nm to a surface treatment with isobutyltrimethoxysilane which is a hydrophobizing agent in an aqueous wet process. The toner subjected to the above-mentioned external addition treatment was further processed to have a number average primary particle diameter of 350 n.
2 parts by weight of strontium titanate of m was surface-treated by using the above Henschel mixer for 3 minutes at a speed of 30 m / s and externally added to obtain a toner a.

Further, a toner in which only hydrophobic silica and hydrophobic titanium oxide were externally added without producing the external addition of strontium titanate in the above-mentioned post-treatment method was prepared as a toner b.

(Carrier Manufacturing Method) The following materials were used for manufacturing the binder type carrier in the present invention. Resin 1 Acrylonitrile resin (Acrylonitrile 65
%, Butadiene 20%, methyl acrylate 15% copolymer) Resin 2 Styrene acrylic resin (styrene monomer / methacrylic acid alkyl ester copolymer, Tg = 67)
C, Tm = 135 [deg.] C. Resin 3 Thermoplastic polyester resin (polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane / terephthalic acid / dodecylsuccinic acid copolymer, Tg = 70) Magnetic powder 1 Magnetite fine powder (BL-600, manufactured by Titanium Industry Co., Ltd.) Additive 1 Amino-modified silicone oil (SF841)
7, Toray Dow Corning Silicone Co., Ltd. Additive resin 1 Amino group-containing acrylic resin (NE761)
2, Kao, amine value 7.5) Additive resin 2 Amino group-containing polyether (amine value 1
5, Tm = 95 ° C.) First, a carrier production method for development using a non-contact development method and an evaluation result of a formed image by this method will be described.

(Example 1) 95 parts of "resin 1", 450 parts of "magnetic powder 1" and 5 parts of "additive 1" were thoroughly mixed with a Henschel mixer, and then a vent twin-screw extruder (PC) was used.
M-65; manufactured by Ikegai Iron Works Co., Ltd., melt-kneaded at 180 ° C., coarsely crushed by a feather mill, and mechanical crusher (ACM).
-10 type; manufactured by Hosokawa Micron Co., Ltd., finely pulverized, and classified by an air classifier (MS-1 type; manufactured by Hosokawa Micron Co., Ltd.), and then further heat treated (Suffusing System SFS-2 type; Nippon Pneumatic Industrial Co., Ltd.) Manufactured by K.K.) at 300 ° C., volume average particle diameter 30 μm
Got a career. Examples 2 to 12 and Comparative Examples 1 to 4 Carriers were obtained in the same manner as in the production method of Example 1, except that the binder resin, silicone oil and other additives were used in the amounts shown in Table 1. . (Floating carrier ratio) 15 g of ion-exchanged water was put into a sample bottle of 50 cm ³ , and 0.30 g of the carrier obtained in Examples 1 to 12 was weighed and put therein. The sample bottle was stirred with a roll mill at 120 ppm for 1 minute, and further dispersed with an ultrasonic shaker for 1 minute. After standing for 5 minutes, the floating carrier on the liquid surface of the sample bottle was filtered, and the weight after drying was weighed. When the floating carrier ratio I was calculated by the following formula, it became as shown in Table 1.

[0112]

[Formula 2]

Similarly, a 50% by weight aqueous methanol solution was prepared and the floating carrier ratio II was measured. The results shown in Table 1 were obtained.

(Preparation of Developer) The carrier obtained as described above and the above-mentioned toner were compounded so that the weight ratio of toner: carrier is as shown in Table 1, and the mixture was prepared at 50 cm ³
Put it in a polybin and rotate it at 120 rpm at 1 rpm.
The developer was prepared by spinning for 10 minutes or 100 minutes.

[0115]

[Table 1]

(Printing durability condition) Printing durability condition is as follows.
In the developing device (10) of FIG. 1, the developing sleeve (1
The distance between the magnetic blade (13) and the magnetic blade (13) is set to 0.4 mm, and the carrying amount of the developer (1) carried to the developing area by the developing sleeve (11) is adjusted to 5.0 mg / cm ^2. The peripheral velocity of the body (2) is adjusted to 165 mm / s, the peripheral velocity of the developing sleeve (11) is adjusted to 300 mm / s, and the surface potential of the portion of the photoreceptor (2) supplying the toner T is -450 V, the toner The surface potential of the portion not supplied with T was set to −100V.

Then, in the developing area where the developing sleeve (11) and the photoconductor (2) face each other, a DC power source of -350 V and a peak / peak value V _p-p from the developer bias power source (12). 1.5kV, frequency 3kHz
An inversion development was carried out by applying a developing bias voltage superposed with an AC voltage having a duty ratio (development: recovery) of 1: 1 with the rectangular wave of No. 1 to form an image sample.

Under N / N environment (temperature 25 ° C./humidity 45
%), H / H environment (temperature 30 ° C / humidity 85%) and L / L environment (temperature 10 ° C / humidity 15%), B / W ratio 1
An image of 5% was copied on 160,000 sheets and evaluated when the specified number of sheets were copied. In this evaluation, toner was replenished immediately before each evaluation.

(Charge Amount) The charge amount was measured when copying a specified number of sheets. When measuring the amount of charge, it was measured using the apparatus shown in FIG. First, 1 g of the developer weighed with a precision balance is uniformly placed on the entire surface of the conductive sleeve (21), and the rotation speed of the magnet roll (22) provided in the conductive sleeve (21) is adjusted. 100
It was set to 0 rpm. And the bias power supply (23)
A bias voltage of 3 kV, which is opposite to the charging potential of the toner, is applied, the conductive sleeve (21) is rotated for 1 minute, and the potential Vm at the cylindrical electrode (24) at the time when the conductive sleeve (21) is stopped And the weight of the toner attached to the cylindrical electrode (24) was measured by a precision balance to determine the average charge amount of the toner.

[0120]

[Table 2]

As shown in Table 2, when a toner containing no strontium titanate was used (Comparative Example 2),
When the styrene acrylic resin was used as the binder resin of the carrier (Comparative Example 3) and when the thermoplastic polyester resin was used as the binder resin of the carrier and no amino-modified silicone was contained (Comparative Example 4), the number of copies increased. Since the accompanying decrease in the charge amount is larger than that in the examples, it is understood that the two-component developer of the present invention has sufficiently stable charge performance. (Fog) Images obtained at the time of copying a specified number of sheets were evaluated according to the following ranking. Fog is a phenomenon in which toner adheres to a copy image where a toner image should not be formed, and toner color dots are scattered. ⊚: Fog was not generated at all on the copied image, or some fog was observed by microscopic observation but could not be visually confirmed; ◯: Fog was confirmed by visual observation, but there was no practical problem; Δ: Visual observation Fog can be confirmed by observation and there is a problem in image quality; ×; Fog is over the entire image

[0122]

[Table 3]

As shown in Table 3, a carrier containing no amino-modified silicone (Comparative Example 1), a toner containing no strontium titanate (Comparative Example 2), and a carrier containing styrene acrylic resin were used. (Comparative Example 3) when used as a binder resin of No. 3, and when a thermoplastic polyester resin is used as a binder resin of a carrier and does not contain an amino-modified silicone (Comparative Example 4).
The occurrence of fog with the increase in the number of copied sheets in Example 1 is larger than the result of Example, so that it can be seen that the two-component developer of the present invention shown in Example has sufficiently stable charging performance.

(Color turbidity) Saturation on an image obtained at the time of copying a specified number of sheets was measured using a color difference meter (CR-200, manufactured by Minolta Co., Ltd.) and evaluated according to the following ranking. ⊚: Saturation on the image is 105 or more; ◯: Saturation on the image is 100 to 105; Δ: Saturation on the image is 90 to 100; ×; Saturation on the image is 90 or less

[0125]

[Table 4]

As shown in Table 4, when styrene acrylic resin was used as the binder resin of the carrier (Comparative Example 3) and when thermoplastic polyester resin was used as the binder resin of the carrier and no amino-modified silicone was contained. In (Comparative Example 4), the decrease in saturation was severe, while the change in the example sample was small,
It can be seen that the two-component developer in the present invention has sufficiently stable charging performance.

Next, a carrier generation method for development using the contact development method and the evaluation result of a formed image by this method will be described.

(Examples 13 to 19 and Comparative Examples 5 to 8)
A developer was obtained in the same manner as in the manufacturing method of Example 1 except that the binder resin, silicone oil and other additives were used in the amounts shown in Table 5.

[0129]

[Table 5]

The printing durability conditions are as follows. The developer is loaded in a commercially available copying machine (CF70: manufactured by Minolta Co., Ltd.), and the developer transport amount is set to 60 mg / cm ² , under N / N environment (temperature 25 ° C./humidity 45%), H / H environment. Lower (Temperature 30
C / humidity 85%) and L / L environment (temperature 10 ° C / humidity 15%) made 160,000 copies of B / W ratio 15% image,
The evaluation was performed when copying the specified number of sheets. In this evaluation, toner was replenished immediately before each evaluation. (Amount of charge) The amount of charge was measured in the same manner as in the case of the non-contact developing method, and the results shown in Table 6 were obtained.

[0131]

[Table 6]

As shown in Table 6, a carrier containing no amino-modified silicone (Comparative Example 5), a toner containing no strontium titanate (Comparative Example 6), and a carrier containing styrene acrylic resin were used. (Comparative Example 7) when used as a binder resin of No. 3, and when a thermoplastic polyester resin is used as a binder resin of a carrier and does not contain an amino-modified silicone (Comparative Example 8).
In each of the examples, the charge amount was maintained longer than that of each of the comparative examples, and it can be seen that the two-component developer of the present invention has sufficiently stable charging performance. (Fog) Fog was evaluated in the same manner as in the case of the non-contact development method.

[0133]

[Table 7]

As shown in Table 7, a carrier containing no amino-modified silicone (Comparative Example 5), a toner containing no strontium titanate (Comparative Example 6), and a carrier containing styrene acrylic resin were used. (Comparative Example 7) when used as a binder resin of No. 3, and when a thermoplastic polyester resin is used as a binder resin of a carrier and does not contain an amino-modified silicone (Comparative Example 8).
In each of the comparative examples, the decrease in the saturation with the increase in the number of copies is large, while in the examples, the change in the saturation is small. Therefore, it can be seen that the two-component developer of the present invention has sufficient charging performance. .

In the present specification, the average particle size of the carrier was measured by measuring the relative weight distribution by particle size using a Coulter Multisizer (manufactured by Beckman Coulter, Inc.) with an 280 μm aperture tube. An aperture tube of 100 μm was used for measuring the average particle diameter of the toner.

[0136]

EFFECT OF THE INVENTION By using the two-component developer of the present invention, a developer having stable charging performance against environmental changes and little deterioration in charging performance over a long period of time can be obtained. By the developing method described above, it is possible to form an image free from noise such as fog and color turbidity for a long period of time.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a developing device using a two-component developer of the present invention.

FIG. 2 is a schematic configuration diagram of an apparatus for measuring the charge amount of a two-component developer of the present invention.

[Explanation of symbols]

1; developer 2; photoconductor 10: Developing device 11; Development sleeve 11a; magnet roller 12; Development bias power supply 13; Control member 13a; magnetic blade 14: Toner container 15; Supply roller 16; Agitator T: Toner 21: Conductive sleeve 22: Magnet roll 23: Bias power supply 24: Cylindrical electrode

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 501 501 G03G 9/08 381 507 15/08 507E (72) Inventor Osamu Maeda Osaka City Central Osaka 2-13-3 Azuchi-cho, Osaka International Building Minolta Co., Ltd. (72) Inventor Yuji Shintani 2-3-3 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Co., Ltd. (72) Inventor Nishikawa Tomoharu 2-13-13 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Prefecture F-term in Osaka International Building Minolta Co., Ltd. (reference) 2H005 AA08 AB03 BA00 BA03 CA02 CA12 CB10 CB13 DA02 EA05 EA10 FA02 2H077 AC12 AD06 AD13 AD24 AD36 EA03 EA15 EA16

Claims (5)

[Claims] 1. A two-component developer comprising a carrier and a negatively chargeable toner, wherein the toner particles prepared by a wet granulation method are externally added with at least hydrophobic silica fine particles and strontium titanate fine particles. A two-component developer, wherein the carrier is a toner containing an ethylenically unsaturated nitrile resin, an amino-modified silicone oil, and magnetic powder. 2. The two-component developer according to claim 1, wherein the carrier is a carrier containing an amino group-containing acrylic resin and / or an amino group-containing polyether. 3. The carrier floating on the liquid surface when the carrier is added to water is 50 to 90% by weight of the total amount, and when the carrier is added to a 1: 1 mixed solvent of water and methanol. 10% by weight of the total amount of floating carrier on the liquid surface
The two-component developer according to claim 1 or 2, which contains the carrier as described above. 4. A two-component developer comprising a carrier and a negatively chargeable toner is used to form a developer layer on a developer carrying member, and the developer layer is conveyed to a position facing the electrostatic latent image carrying member, and the static latent image carrying member is conveyed. In a developing method including a step of electrostatically adhering the negatively chargeable toner to an electrostatic latent image on an electrostatic latent image carrier to make it visible, the negatively chargeable toner has a volume average particle diameter of 3 to 8 μm. Toner,
The carrier is a carrier having a volume average particle size of 20 to 40 μm, and the transport amount of the two-component developer transported by the developer layer is 3 to 15 mg / cm ² , and the developer layer and the electrostatic latent layer are The two-component according to any one of claims 1 to 3, wherein the two components are in non-contact with the image carrier and cause the toner to fly from the developer layer and adhere onto the electrostatic latent image. Developing method using a developer. 5. A two-component developer comprising a carrier and a negatively chargeable toner is used to form a developer layer on a developer carrying member, and the developer layer is conveyed to a position facing the electrostatic latent image carrying member, and the electrostatic latent image carrying member is conveyed. In a developing method including a step of electrostatically adhering the negatively chargeable toner to an electrostatic latent image on an electrostatic latent image carrier to make it visible, the negatively chargeable toner has a volume average particle diameter of 3 to 8 μm. Toner,
The carrier is a carrier having an average volume particle size of 40 to 70 μm, and the transport amount of the two-component developer transported by the developer layer is 40 to 80 mg / cm ² , and the developer layer and the electrostatic latent layer are 4. The toner according to claim 1, wherein the toner is attached to the electrostatic latent image in a state of being in contact with the image carrier.
A developing method using the two-component developer according to any one of 1.