JP2000250262A - Electrostatic latent image developing toner, its production, developer using same and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve transferability to an image support and to maintain high image quality over a long period of time. SOLUTION: At least resin particles and colorant particles are salted out and fused to obtain the objective toner. The resin particles are obtained by a polymerization method including the addition of a polymerization initiator to an aqueous medium in which a polymerizable monomer forming the resin particles has been emulsified at an average addition rate A in the range from 0.1 wt.% of the total weight of the polymerizable monomer per 1 min to 5 wt.% of the total weight of the polymerizable monomer per 1 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic latent image (hereinafter also referred to simply as "toner"), a method for producing the same,
The present invention relates to a developer using the toner and an image forming method.

[0002]

2. Description of the Related Art As a toner for copiers and printers utilizing electrostatic latent image development, toner by a pulverization method is currently the mainstream, but in recent years, the demand for higher image quality from the market has increased, and the cost has been reduced. Since small-sized particles having a sharp particle size distribution can be produced, a method for producing a polymerized toner using an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, or the like has been actively proposed (for example, an emulsion polymerization method). Are disclosed in JP-A-63-186253 and JP-A-6-329.
947, JP-A-9-96919, etc.).

[0003] Among them, a so-called emulsion-association-type polymerized toner production method in which emulsion polymerized particles are used to form an aggregate with a colorant or the like and then fused to produce non-spherical particles due to the characteristics of the method. Therefore, the toner has an advantage that a toner having a small particle diameter and excellent cleaning properties can be produced as compared with a suspension polymerization toner that can obtain a spherical toner. However, in the conventional method for producing an emulsion-association type polymerized toner, when the toner is mounted on an actual copier / printer, problems such as repelling of characters may occur at the time of transfer to an image support. Although the reason for this is not clear, it is presumed that there is a problem in the uniformity of assembling the particles, and cissing is likely to occur due to the presence of a low-charge toner at the time of transfer to the image support. You.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a toner for developing an electrostatic latent image which has good transferability to an image support and can maintain high image quality for a long period of time. An object of the present invention is to provide a toner for developing a latent electrostatic image and a method for producing the same, and a developer and an image forming method using the toner for developing a latent electrostatic image of the present invention.

[0005]

The above object of the present invention is achieved by the following constitution.

[0006] 1. In a toner for developing an electrostatic latent image in which at least resin particles and colorant particles are salted out and fused, the resin particles are polymerized in an aqueous medium in which a polymerizable monomer constituting the resin particles is emulsified. A toner for developing an electrostatic latent image, which is a resin particle obtained by a polymerization method in which an initiator is added at the following average addition rate A.

(0.1 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (5 wt% / min of the total weight of the polymerizable monomers used) 2. The toner for developing an electrostatic latent image according to 1, wherein the average addition speed A is as follows.

(0.3 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (3 wt% / min of the total weight of the polymerizable monomers used) In a method for producing a toner for developing an electrostatic latent image having at least resin particles and colorant particles, the resin particles comprise a polymerization initiator in an aqueous medium in which a polymerizable monomer constituting the resin particles is emulsified. A method for producing a toner for developing an electrostatic latent image, wherein salting out and fusing the resin particles and the colorant particles obtained by the polymerization method in which the particles are added at the average addition speed A described below.

(0.1 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (5 wt% / min of the total weight of the polymerizable monomers used) 4. The method for producing a toner for developing an electrostatic latent image according to 3, wherein the average addition speed A is as follows.

(0.3 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (3 wt% / min of the total weight of the polymerizable monomers used) In a developer having magnetic particles and toner for developing an electrostatic latent image obtained by salting out and fusing at least resin particles and colorant particles, the resin particles emulsify the polymerizable monomer constituting the resin particles. A developer comprising resin particles obtained by a polymerization method in which a polymerization initiator is added to the aqueous medium at an average addition rate A shown below.

(0.1 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (5 wt% / min of the total weight of the polymerizable monomers used) 6. The developer according to 5, wherein the average addition speed A is as follows.

(0.3 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (3 wt% / min of the total weight of the polymerizable monomers used) The latent image formed on the electrostatic latent image forming body is developed with a developer having at least a toner for developing an electrostatic latent image, and then transferred to an image support and thermally fixed to obtain an image. In this case, the toner is a toner for developing an electrostatic latent image obtained by salting out and fusing at least resin particles and colorant particles, and the resin particles emulsify a polymerizable monomer constituting the resin particles. Resin particles obtained by a polymerization method in which a polymerization initiator is added to the aqueous medium at the following average addition rate A,
An image forming method, comprising: cleaning the electrostatic latent image developing toner remaining on the electrostatic latent image forming body.

(0.1 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (5 wt% / min of the total weight of the polymerizable monomers used) 8. The image forming method according to 7, wherein the average addition rate A is as follows.

(0.3 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (3 wt% / min of the total weight of the polymerizable monomer used) That is, as a result of intensive studies, the present inventors pay attention to the properties of particles during emulsion polymerization. As a result, they have found that the object of the present invention can be achieved, and have completed the present invention.

In the present invention, the surface property of the emulsion polymer particles produced in the emulsion polymerization is made uniform by using a specific method for adding the polymerizable initiator during the emulsion polymerization. As a result, the toner particles themselves formed by associating using the particles can also have uniform properties, the charge amount becomes uniform, and problems such as repelling during transfer to the image support are reduced. A toner that does not generate can be obtained.

Although the reason for this is not clear, the emulsion polymerization ability of the initiator can be made constant by sequentially adding the polymerization initiator, and the formed emulsion-polymerized resin particles themselves can be made uniform. It is presumed that.

The toner of the present invention is obtained by salting out and fusing at least resin particles and colorant particles prepared by emulsion polymerization. This salting-out, and fusion, the salting-out agent is added to water in which the emulsion polymerization particles and the colorant particles are dispersed,
If necessary, an infinitely soluble organic solvent is added, followed by heating for salting out and simultaneously fusing to prepare toner particles. In this method, unlike the method of fusing after forming the aggregated primary particles of the resin particles and the colorant particles, the method is capable of fusing without passing through an intermediate stage to prepare toner particles. Salting out,
The uniformity of the toner particles formed by fusing is not impaired, and a toner having a uniform chargeability can be stably obtained.

Hereinafter, the present invention will be described in detail.

<< Materials >> [Monomer] As the polymerizable monomer, a radical polymerizable monomer is an essential component, and a crosslinking agent can be used as necessary. Further, it is preferable to contain at least one radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group described below.

(1) Radical polymerizable monomer The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used. Also, to satisfy the required characteristics,
Species or a combination of two or more can be used.

This polymerizable monomer is preferably added to an aqueous medium before adding a polymerization initiator.

Specifically, aromatic vinyl monomers, (meth) acrylate monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers Monomers, halogenated olefin monomers and the like 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- Styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

(Meth) acrylate monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate Butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl benzoate and the like.

Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

Examples of the monoolefin-based monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

Examples of the diolefin-based monomer include butadiene, isoprene, chloroprene and the like.

As the halogenated olefin monomer,
Vinyl chloride, vinylidene chloride, vinyl bromide and the like.

(2) Crosslinking Agent As the crosslinking agent, a radical polymerizable crosslinking agent may be added in order to improve the properties of the toner. Examples of the radical polymerizable crosslinking agent include divinylbenzene, divinylnaphthalene,
Examples thereof include those having two or more unsaturated bonds such as divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

(3) Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group For example, an amine compound such as a carboxyl group-containing monomer, a sulfonic acid group-containing monomer, a primary amine, a secondary amine, a tertiary amine, and a quaternary ammonium salt may be used. it can.

Examples of the radical polymerizable monomer having an acidic group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, monobutyl maleate, and carboxylic acid group-containing monomers. And monooctyl maleate.

Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate and the like.

These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.

Examples of the radical polymerizable monomer having a basic group include amine compounds, such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary of the above four compounds. Ammonium salt, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide,
Piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide; vinylpyridine, vinylpyrrolidone; vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diallylmethylammonium chloride, N, N- Diallylethylammonium chloride and the like can be mentioned.

In the present invention, the above-mentioned radical polymerizable monomers can be used in combination, and are preferably an aromatic vinyl monomer, a (meth) acrylate monomer, and a radical polymerizable monomer having an acidic group. It is preferable to use a monomer or a radical polymerizable monomer having a basic group.

As the radical polymerizable monomer used in the present invention, a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group is 0.1 to 15% of the whole monomer. Preferably, the radical polymerizable cross-linking agent is used in the range of 0.1 to 10% by weight, based on the total radical polymerizable monomer, depending on its properties.

[Chain transfer agent] For the purpose of adjusting the molecular weight, a commonly used chain transfer agent can be used.

The chain transfer agent is not particularly restricted but includes, for example, mercaptans such as octyl mercaptan, dodecyl mercaptan and tert-dodecyl mercaptan, and styrene dimers.

[Polymerization Initiator] The radical polymerization initiator used in the present invention can be appropriately used as long as it is water-soluble.
For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4'-azobis-4-cyanovaleric acid and its salts, 2,2'-azobis (2-amidinopropane) salts, etc.), peroxides And the like.

Further, the above radical polymerization initiator can be combined with a reducing agent, if necessary, to form a redox initiator. By using a redox-based initiator, the polymerization activity is increased, the polymerization temperature can be reduced, and a further reduction in the polymerization time can be expected.

As the polymerization temperature, any temperature may be selected as long as it is equal to or higher than the minimum radical generation temperature of the polymerization initiator, but for example, a range of 50 ° C. to 90 ° C. is used. However, it is also possible to polymerize at room temperature or higher by using a combination of a polymerization initiator started at room temperature, for example, a hydrogen peroxide-reducing agent (such as ascorbic acid).

It is necessary to add the polymerization initiator to the aqueous medium at the following average addition rate A.

(0.1 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (5 wt% / min of the total weight of the polymerizable monomers used) Preferably, the following conditions are satisfied.

(0.3 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (3 wt% / min of the total weight of the polymerizable monomers used) [Surfactant] For performing emulsion polymerization using the above-described radical polymerizable monomer. Requires emulsion polymerization using a surfactant. The surfactant that can be used at this time is not particularly limited, but the following ionic surfactants can be mentioned as preferred examples.

Examples of the ionic surfactant include sulfonates (sodium dodecylbenzenesulfonate, sodium polyoxyethylenebenzenesulfonate), and sulfate salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate). And the like, and fatty acid salts (such as sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, and calcium oleate).

Further, a nonionic surfactant can also be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, an ester of polyethylene glycol and higher fatty acid, an alkylphenol polyethylene oxide, an ester of higher fatty acid and polyethylene glycol, an ester of higher fatty acid and polypropylene oxide, a sorbitan ester Etc. can be given.

In the present invention, these are mainly used as emulsifiers at the time of emulsion polymerization, but they may be used in other steps or for other purposes.

Also, a fluorocarbon surfactant can be used.

[Colorant] Examples of the colorant include inorganic pigments and organic pigments.

Conventionally known inorganic pigments can be used. Although any pigment can be used, specific inorganic pigments are exemplified below.

Examples of black pigments include furnace black, channel black, acetylene black,
Carbon black such as thermal black and lamp black, and magnetic powder such as magnetite and ferrite are also used.

These inorganic pigments can be used alone or in combination of two or more as desired. The amount of the pigment added is about 2 to about 20 parts, preferably about 3 to 15 parts, based on the polymer.

When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, from the viewpoint of imparting predetermined magnetic characteristics, 20 to 60
It is preferable to add by weight.

As the organic pigment, conventionally known organic pigments can be used. Although any pigment can be used, specific organic pigments are exemplified below.

The pigments for magenta or red include:
C. 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. Pigment Red 48: 1, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 57:
1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139,
C. I. Pigment red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I.
I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222 and the like.

Examples of orange or yellow pigments include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12,
C. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I.
I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I.
Pigment Yellow 138 and the like.

As pigments for green or cyan,
C. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3,
C. 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 about 2 to about 20 parts, preferably about 3 to 15 parts, based on the polymer.

The colorant can be used after surface modification. As the surface modifier, a conventionally known one can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used.

Examples of the silane coupling agent include alkoxysilanes such as methyltrimethoxysilane, phenyltrimethoxysilane, methylphenyldimethoxysilane and diphenyldimethoxysilane, siloxanes such as hexamethyldisiloxane, γ-chloropropyltrimethoxysilane, vinyl Trichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
γ-ureidopropyltriethoxysilane and the like.

As the titanium coupling agent, for example,
TTS, 9S, 38S, 41B, 46B, 5B, which are commercially available under the trade name "Plenact" manufactured by Ajinomoto Co.
5, 138S, 238S, etc., commercial products A-
1, B-1, TOT, TST, TAA, TAT, TL
A, TOG, TBSTA, A-10, TBT, B-2,
B-4, B-7, B-10, TBSTA-400, TT
S, TOA-30, TSDMA, TTAB, TTOP and the like.

As the aluminum coupling agent, for example, "Plenact AL-M" manufactured by Ajinomoto Co., Inc. and the like can be mentioned.

These surface modifiers are added to the colorant in an amount of 0.1%.
It is preferably added in an amount of from 0.1 to 20% by weight, more preferably about 0.1 to 5% by weight.

The toner obtained by the present invention can be used by adding a so-called external additive for the purpose of improving the fluidity and the cleaning property. These external additives are not particularly limited, and various inorganic fine particles,
Organic particulates and lubricants can be used.

Conventionally known inorganic fine particles can be used. Specifically, silica, titanium, alumina fine particles and the like can be preferably used. These inorganic fine particles are preferably hydrophobic. Specifically, as silica fine particles, for example, Nippon Aerosil Co., Ltd.
Commercially available products R-805, R-976, R-974, R-
972, R-812, R-809, HVK-2150, H-200 manufactured by Hoechst Co., Ltd., and commercial products TS-720, TS-530, TS-610, H manufactured by Cabot Co., Ltd.
-5, MS-5 and the like.

As the titanium fine particles, for example, commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., and commercially available products MT-100S and MT-100B manufactured by Teica Co., Ltd.
MT-500BS, MT-600, MT-600SS,
JA-1, commercial product TA-300S manufactured by Fuji Titanium Co., Ltd.
I, TA-500, TAF-130, TAF-510,
TAF-510T, commercial product IT- manufactured by Idemitsu Kosan Co., Ltd.
S, IT-OA, IT-OB, IT-OC and the like.

Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd. and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.

Examples of the lubricant include salts of zinc, aluminum, copper, magnesium, calcium and the like of stearic acid, salts of zinc, manganese, iron, copper and magnesium of oleic acid, and zinc, copper, magnesium and calcium of palmitic acid. Metal salts of higher fatty acids such as salts of linoleic acid such as zinc and calcium, and salts of ricinoleic acid such as zinc and calcium.

The addition amount of these external additives is preferably about 0.1 to 5% by weight based on the toner.

<< Production Step >> The production step of the polymerized toner of the present invention is an emulsion polymerization step of preparing resin particles by emulsion polymerization, and salting out and melting after adding a colorant particle dispersion to the resin particle dispersion. Salting-out / fusing step of applying toner particles, washing step of filtering the obtained toner particles from water to remove a surfactant and the like, drying step of drying the obtained toner particles, and further drying. An external additive adding step (toner forming step) in which the obtained toner is subjected to a crushing treatment as necessary (crushing step) and an external additive is added.

Hereinafter, each step will be described.

[Emulsion Polymerization Step] The emulsion polymerization step of the present invention is basically an emulsion polymerization generally known in the art, and is particularly limited except for the rate of addition of the initiator limited in the present invention. Although not required, for example, the following method can be used.

First, a required amount of a polymerizable monomer is added to an aqueous medium in which a surfactant is dissolved. Next, after degassing with a nitrogen stream, heating is performed to reach a predetermined polymerization temperature, and then a polymerization initiator is added under the addition conditions of the present invention.

In the present invention, it is necessary to add the polymerization initiator to the aqueous medium at the following average addition rate A.

(0.1 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (5 wt% / min of the total weight of the polymerizable monomers used) Preferably, the following conditions are satisfied.

(0.3 wt% of the total weight of the polymerizable monomer used)
% / Min) ≦ (average addition rate A) ≦ (3 wt% / min of the total weight of the polymerizable monomer used) When the average addition rate is lower than 0.1% by weight or less of the polymerizable monomer, The reaction rate becomes slow, and the molecular weight of the resin particles tends to be non-uniform. As a result, the composition itself of the emulsion polymerized particles becomes non-uniform, so that a final distribution of the surface properties of the toner formed by salting out / fusing the resin particles and the colorant particles occurs, and the transferability is reduced. It is estimated that

On the other hand, the average addition rate of the polymerizable monomer was 5.
When the amount is larger than 0% by weight, there is a problem that an aggregate is generated at the time of polymerization, and as a result, particles having properties different from those of the polymer fine particles obtained at the addition rate in the region of the present invention are easily generated. Presumed. As a result, there arises a problem that the transferability is reduced due to the presence of the polymer fine particles thus generated.

The apparatus for adding the polymerization initiator to the reaction phase is not particularly limited. For example, a fixed-quantity liquid sending pump, a dropping funnel and the like can be used.

When a plurality of radically polymerizable monomers are used, it is preferable to add a plurality of polymerizable monomers in an aqueous medium before adding a polymerization initiator. In the present invention, the average addition rate is defined by a weight percentage based on all the radical polymerizable monomers used.

The rate of addition of the initiator according to the present invention is calculated as follows:
The calculation is performed assuming that the polymerization initiator is uniformly present in the aqueous solution in which the initiator is dissolved.

When a chain transfer agent is used for controlling the molecular weight, it is preferable to add it by mixing with a radical polymerizable monomer.

The polymerization temperature and time may be set arbitrarily as long as the emulsion polymerization occurs. Usually, the polymerization is carried out under a nitrogen stream.

This emulsion polymerization step may be carried out a plurality of times under different conditions depending on the desired physical properties of the toner.
Additional polymerization can also be performed where the previous polymerization liquid is present.

Further, a plurality of resin particles having different molecular weights or different compositions may be separately prepared, and a plurality of resin particles may be used to carry out the following salting out / fusion to form a toner. In this case, it is particularly preferable to use resin particles having different molecular weights from the viewpoint of improving the fixability of the toner.
In this case, it is preferable that all of the plurality of resin particles satisfy the configuration of the present invention. The reason for this is that, when a plurality of resin particles having different addition rates of the polymerizable monomer are used, uniform salting-out / fusion cannot be performed, and the shape of the formed toner particles is not good. This is because the problem of uniformity is likely to occur. That is, when all of the plurality of resin particles satisfy the configuration of the present invention, a uniform toner can be prepared.

The resin particles according to the present invention may have a glass transition temperature (abbreviated as Tg) in the range of 10 to 75 ° C., more preferably 40 to 65 ° C. The softening point of the resin particles is preferably in the range of 80 to 220C. As the composition of the resin particles, those containing a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group are particularly preferable. This content is preferably about 0.1 to 20% by weight based on the whole polymer.

The molecular weight of the resin particles according to the present invention is not particularly limited, but is usually from 2,000 to 2,000 in terms of weight average molecular weight.
1,000,000, preferably 8,000-500,
000. The particle diameter of the resin particles prepared by emulsion polymerization is about 20 to 500 nm in weight average diameter.

Here, the softening point of the resin particles indicates a value measured using a Koka type flow tester (manufactured by Shimadzu Corporation). Specifically, the Koka type flow tester “CF
Using a T-500 (manufactured by Shimadzu Corporation), a sample of 1 cm ² was melted and flown out under the conditions of 1 mm in diameter of a die, 1 mm in length, a load of 20 kg / cm ² , and a heating rate of 6 ° C./min. The temperature corresponding to 1/2 of the height from the outflow start point to the outflow end point is shown as the softening point.

The glass transition point of the resin particles is defined by DSC
The intersection between the baseline and the slope of the endothermic peak is defined as the glass transition point. Specifically, using a differential scanning calorimeter, the temperature was raised to 100 ° C., and at that temperature, 3 mi
After being left for n minutes, it is cooled to room temperature at a temperature drop of 10 ° C./min. Next, the sample was heated at a rate of 10 ° C./mi.
When measured at n, the intersection of the extension of the baseline below the glass transition point and the tangent that indicates the maximum slope from the peak rising portion to the peak apex is indicated as the glass transition point.

As a measuring device, DSC-7 manufactured by Perkin Elmer Co. can be used.

The molecular weight distribution of the resin particles indicates the molecular weight in terms of styrene measured by GPC.

The method for measuring the molecular weight of a resin by GPC is described in US Pat.
It is a measurement by GPC (gel permeation chromatography) using HF as a solvent. That is, the measurement sample is 0.5 to 5 mg, more specifically, 1 mg for THF.
, And stirred at room temperature using a magnetic stirrer or the like to sufficiently dissolve. Then, after treating with a membrane filter having a pore size of 0.45 to 0.50 μm, the mixture is injected into GPC. GPC measurement conditions were as follows: stabilize the column at 40 ° C., and set the THF to 1 c / min.
c at a flow rate of 1 mg / cc,
Inject μl and measure. The column is preferably used in combination with a commercially available polystyrene gel column.
For example, Shodex GPC KF-
801,802,803,804,805,806,8
07 combination or TSKgelG1000 manufactured by Tosoh Corporation
H, G2000H, G3000H, G4000H, G5
000H, G6000H, G7000H, TSK gu
and ard column combinations. As the detector, a refractive index detector (IR detector) or a UV detector may be used. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve created using monodisperse polystyrene standard particles. As polystyrene for preparing a calibration curve, about 10 points may be used.

The particle diameter of the resin particles is a weight average particle diameter measured using the above-mentioned dispersion liquid with an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd.

[Salt-out / fusion step] The resin particles produced in the polymerization step are subjected to salt-out and fused to form a non-spherical toner.

In this case, the resin particles and the colorant particles are salted out in water and fused.

In addition to the colorant, a release agent and a charge control agent, which are components of the toner, can be added in this step.

The colorant itself may be used after surface modification. The colorant surface modification method is to disperse the colorant in a solvent,
After the addition of the surface modifier, the temperature is raised and the reaction is carried out. After completion of the reaction, the mixture is filtered, washed and filtered repeatedly with the same solvent, and dried to obtain a pigment treated with a surface modifier.

The colorant particles are prepared by dispersing a colorant in water. This dispersion is performed in a state where the surfactant concentration in water is equal to or higher than the critical micelle concentration (CMC).

The disperser for dispersing the pigment is not particularly limited, but is preferably a disperser such as an ultrasonic disperser, a mechanical homogenizer, a pressure disperser such as Manton-Gaulin or a pressure homogenizer, a sand grinder, a Getzman mill, a diamond fine mill, or the like. The medium type disperser is fried.

As the surfactant used here, the above-mentioned surfactants can be used.

In the step of salting out / fusing, a salting-out agent comprising an alkali metal salt, an alkaline earth metal salt, or the like is added to water in which resin particles and colorant particles are present. And then heating to above the glass transition point of the resin particles to promote salting out and simultaneously fuse. In this step, a method may be used in which an organic solvent that is infinitely soluble in water is added, and the glass transition temperature of the resin particles is substantially lowered to effectively perform fusion.

Here, the alkali metal salt and alkaline earth metal salt as salting-out agents include lithium, potassium, sodium and the like as alkali metals, and magnesium, calcium, strontium, barium and the like as alkaline earth metals. And preferably potassium, sodium, magnesium, calcium and barium. Examples of the salt include chloride, bromide, iodine, carbonate, sulfate and the like.

Further, the organic solvent infinitely soluble in water includes methanol, ethanol, 1-propanol,
2-propanol, ethylene glycol, glycerin,
Acetone and the like can be mentioned, and alcohols of methanol, ethanol, 1-propanol and 2-propanol having 3 or less carbon atoms are preferable, and 2-propanol is particularly preferable.

In the case of salting out / fusing according to the present invention, it is preferable to minimize the time of standing after adding the salting out agent. Although the reason for this is not clear, there is a problem that the aggregation state of the particles fluctuates due to the standing time after salting out, the particle size distribution becomes unstable, and the surface properties of the fused toner fluctuate. appear. The temperature at which the salting-out agent is added must be at least equal to or lower 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 higher than the glass transition temperature of the resin particles, the salting-out / fusion of the resin particles proceeds rapidly, but the particle size cannot be controlled, and There is a problem that particles having a particle size are generated. The range of the addition temperature may be lower than the glass transition temperature of the resin, but is generally 5 ° C.
To 55 ° C, preferably 10 ° C to 45 ° C.

In the present invention, it is necessary to use a method in which the salting-out agent is added at a temperature lower than the glass transition temperature of the resin particles, and thereafter, the temperature is raised as quickly as possible, and the temperature is raised to the glass transition temperature of the resin particles. is there. The time until the temperature rise is preferably less than 4 hours. Further, it is necessary to raise the temperature promptly, but the rate of temperature increase is preferably 0.10 ° C./min or more. The upper limit is not particularly clear, but when the temperature is raised instantaneously, salting out proceeds rapidly, and there is a problem that the particle size cannot be controlled. Thus, the upper limit is preferably 5 ° C./min or less.

Here, the particle diameter of the toner obtained by salting out / fusing is preferably 3 to 10 μm in terms of volume average particle diameter. The volume average particle size of this toner is determined by the Coulter Counter TA.
-II, Coulter Multisizer, SLAD1100 (Shimadzu Corporation laser diffraction particle size analyzer) or the like. Aperture diameter = 100 for Coulter Counter TAII and Coulter Multisizer
3 shows a result of measurement using a particle size distribution in a range of 2.0 to 40 μm using an aperture of μm.

[Filtration / Washing Step] The toner particles obtained in the salting-out / fusion step are filtered and washed to remove impurities such as a surfactant and a salting-out agent attached to the toner particles. . As this method, filtration is performed by centrifugation, Nutsche, filter press, or the like, and then washing is performed with washing water.

[Drying Step] The toner after washing and filtration is dried and used. The drier used at this time is not particularly limited, but a spray drier, a vacuum freeze drier, a reduced pressure drier and the like are used, and preferably, a stationary shelf drier, a mobile shelf drier, a fluidized bed drier, A rotary dryer, a stirring dryer and the like are used. At the time of drying, the water content is preferably 5% by weight or less, more preferably 2% by weight or less.

[Crushing Step] This step may not be particularly required, but may be in a weakly agglomerated state after drying. In this case, a jet mill, a Henschel mixer,
The crushing may be performed by using a mechanical crushing device such as a coffee mill or a food processor.

[Tonerization Step] In the tonerization step, the toner particles obtained above may be used as they are, but for the purpose of improving, for example, fluidity, chargeability, and cleaning properties, the above-mentioned external additive is used. An agent may be added. As a method of adding the external additive, various known mixing devices such as a Turbula mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.

The toner of the present invention may be used alone, or may be used as a magnetic or non-magnetic one-component toner, or may be mixed with magnetic particles such as a carrier and used as a two-component developer.

The toner may contain a material capable of imparting various functions as a toner material in addition to the colorant. Specific examples include a fixing property improving agent and a charge control agent. These components may be added to the resin particles at the stage of emulsion polymerization by adding the dispersion, the salting-out / fusion step may be simultaneously added to the resin particles and the colorant particles and included in the toner, or the resin particles themselves. It can be added by various methods such as a method of adding it to an aqueous solution. As a preferred method, the charge control agent particles and / or
Or a method in which fixability improver particles are added in the form of a dispersion and the charge control agent particles and / or fixability improver particles in the state of the dispersion together with the resin particles and the colorant particles in the salting-out / fusion step described above. And salting out / fusing.

As the fixability improving agent, various known ones which can be dispersed in water can be used. Specific examples include olefin waxes such as polypropylene and polyethylene, modified products thereof, natural waxes such as carnauba wax and rice wax, and amide waxes such as fatty acid bisamide.

The charge control agents are also various known ones.
What can be dispersed in water can also be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines,
Quaternary ammonium salt compounds, azo-based metal complexes, salicylic acid metal salts or metal complexes thereof.

The particles of the charge control agent and the fixability improving agent have a number average primary particle diameter of 10 to 50 in a dispersed state.
Preferably, the thickness is about 0 nm.

<< Developer >> The developer used in the present invention includes:
Although a one-component developer or a two-component developer may be used, a two-component developer is preferable. When used as a one-component developer, there is a method of using the toner as it is as a non-magnetic one-component developer, but usually 0.1 to 5 μm
About m of magnetic particles are contained and used as a magnetic one-component developer. As a method of containing the same, it is common to make the non-spherical particles contain the same as the coloring agent.

Further, it can be mixed with a carrier and used as a two-component developer. In this case, as the magnetic particles, conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Particularly, ferrite particles are preferable. The magnetic particles preferably have a volume average particle size of 15 to 100 μm, more preferably 25 to 60 μm. The volume average particle size of the carrier is typically measured by a laser diffraction type particle size distribution analyzer “HELOS” equipped with a wet disperser (SYMPATIC (SYMPIC)
(ATEC)).

The carrier is preferably a carrier further coated with a resin or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. Although there is no particular limitation on the resin composition for coating, for example, an olefin resin, a styrene resin, a styrene / acrylic resin, a silicone resin, an ester resin, a fluorine-containing polymer resin, or the like is used. The resin for forming the resin dispersion type carrier is not particularly limited, and known resins can be used.For example, styrene acrylic resin, polyester resin, fluorine resin, phenol resin, and the like can be used. it can.

<< Image Forming Method >> Next, the image forming method of the present invention will be described.

FIG. 1 is a sectional view showing an example of a developing device (developing device) used in the image forming method of the present invention. In this figure, reference numeral 41 denotes a developing sleeve which is a developer carrying body having a fixed magnet 42 therein, 46 denotes a regulating rod which is a developer carrying amount regulating member, 47 denotes a scraper which is a developer scraping member, and 48 denotes a scraper which is a developer scraping member. A stirring roller as a developer stirring member, 4
Reference numeral 9 denotes a casing of a developing device, 50 denotes a two-component developer including a toner T and a carrier C, 51 denotes a power supply as bias applying means, and 10 denotes an image forming body in which a photosensitive layer 12 is formed on a conductive substrate 11. body drum, D ₁ is the closest distance of the developing sleeve 41 and the photosensitive drum 10, also arrow of the photosensitive drum 10 and the developing sleeve 41 shows the direction of rotation.

The developing sleeve 41 is made of, for example, aluminum,
It is a cylinder of 0.5 to 3 cm in diameter made of non-magnetic and conductive metal such as stainless steel, and has a surface roughness (Rz) of 1 to 3.
It is processed to be 30 μm. Inside the developing sleeve 41, 4 to 12 magnetized to the N pole or the S pole
A magnet body 42 such as a columnar or split chopstick-shaped (column-shaped) aggregate having magnetic poles is fixedly provided, and the developing sleeve 41 is rotatable with respect to the magnet body 42.

The casing 49 is a casing made of, for example, an insulating resin such as acryl or polycarbonate. In the casing 49, the developing sleeve 41 including the fixed magnet body 42, the supply roller 45, and the scraper 4 are provided.
7 and the stirring roller 48 are disposed,
A regulating rod 46 is disposed at the outlet of the control rod.

A two-component developer 50 composed of toner T and carrier C is stored inside the casing 49. The two-component developer 50 is stirred and mixed by the stirring roller 48 and is supplied by the supply roller 45 and adheres to the developing sleeve 41 to form a magnetic brush. The magnetic brush is transported while the transport amount is regulated by the regulating rod 46 as the developing sleeve 41 rotates.

An AC voltage having a DC component from the power supply 51 is applied to the developing sleeve 41.
A strong oscillating electric field is formed in the gap between the photosensitive drum 10 and the photosensitive drum 10. Due to the strong oscillating electric field, the toner T flies away from the carrier C, and a toner cloud is generated. As a result, a flight toward the latent image on the photosensitive drum 10 occurs, and a toner image is formed on the photosensitive drum 10.

In the contact type development, the layer thickness of the developer containing the toner of the present invention is 0.1 to 0.1 in the development area.
It is preferably 8 mm, particularly preferably 0.4 to 5 mm.
The gap between the photosensitive drum and the developer sleeve is 0.1 mm.
It is preferably from 15 to 7 mm, particularly preferably from 0.2 to 4 mm.

In the non-contact developing system, the developer layer formed on the developer sleeve does not come into contact with the surface of the photosensitive drum. In order to constitute this developing system, the developer layer is thin. It is preferably formed of a layer. According to this method, a developer layer having a thickness of 20 to 500 μm is formed in a development area on a developing sleeve surface, and a gap between the photoconductor and the developer sleeve surface is larger than the developer layer.

The thin layer is formed by a magnetic blade using a magnetic force, a method of pressing a developer layer regulating rod against the surface of a developer carrier, or the like. Furthermore, there is a method in which a urethane blade, a phosphor bronze plate or the like is brought into contact with the surface of the developer carrier to regulate the developer layer. The pressing force of the pressing regulating member is 1 to 15
gf / mm is preferred. If the pressing force is small, the conveyance is likely to be unstable due to insufficient regulation force.
When the pressing force is large, the stress on the developer becomes large, so that the durability of the developer tends to decrease. A preferred range is 3 to 10 gf / mm. The gap between the developer carrier and the surface of the photoconductor needs to be larger than the developer layer. Further, when a developing bias is applied at the time of development, either a method of applying only a DC component or a method of applying an AC bias may be used.

The diameter of the developer sleeve is 1
Those having a thickness of 0 to 40 mm are preferred. When the diameter is small, the mixing of the developer is insufficient, and it is difficult to ensure sufficient mixing to give sufficient charge to the toner. When the diameter is large, the centrifugal force on the developer becomes large. , The problem of toner scattering is likely to occur.

FIG. 2 is a sectional view showing an example of an image forming apparatus used in the image forming method of the present invention. In this figure, 10 is a photosensitive drum as an image forming body, 20 is a scorotron charger as charging means, 25 is an image reading unit,
30 is an image writing unit using a laser beam as an exposure unit, 40A, 40B, 40C and 40D are developing devices shown in FIG. 1 containing two-component developers of different colors, respectively, and 60 is a first paper feed roller 61 and Second paper feed roller 62
, A transfer corona charger 70 as a transfer unit, 75 a corona charger for separation as a separation unit, 80
Denotes a conveying unit, 85 denotes a fixing unit, 90 denotes a cleaning device having a cleaning blade 91, and 95 denotes a pre-charging exposure lamp. Arrows in the drawing indicate the rotation direction of the photosensitive drum 10.

The image forming method according to the present invention will be described with reference to FIG. This is a multicolor image forming process. The basic operation is as follows. First, a copy start command is sent from an operation unit (not shown) to a control unit (not shown), and the photosensitive drum 10 starts rotating. As the photosensitive drum 10 rotates, its peripheral surface is uniformly charged by the scorotron charger 20. In the image reading section 25, optical information from the document is converted into an electric signal, and the electric signal is subjected to image processing,
It is input to the image writing unit 30. The charged photosensitive drum 10 is irradiated with a laser beam from the image writing unit 30 to form a latent image on the photosensitive drum 10. The latent image on the photosensitive drum 10 is developed by any of the developing devices 40A, 40B, 40C and 40D, and a toner image is formed on the photosensitive drum 10.

The photosensitive drum 1 on which the toner image is formed
0 is uniformly charged again by the scorotron charger 20 and is irradiated with a laser beam by the image writing section 30 to form the next latent image. The latent images on the photosensitive drum 10 are stored in the developing devices 40A, 40B, 40C.
Or 40D, and the next toner image is superimposed on the photosensitive drum 10.

In the present embodiment, the latent image forming process described above
The development process is repeated four times, and four color toner images are superimposed on the photosensitive drum 10.

The paper feed unit 60 stores recording paper as a transfer material, and includes a first paper feed roller 61 and a second paper feed roller 6.
2, the toner image is sent to the transfer corona charger 70 in synchronization with the toner image superimposed on the photosensitive drum 10.
The toner image superimposed on the photosensitive drum 10 is transferred onto recording paper (recording material) by the corona charger 70 for transfer, and the recording paper is separated from the photosensitive drum 10 by a corona charger 75 for separation. Is done. The recording paper on which the toner image has been transferred is conveyed to a fixing unit 85 via a conveying unit 80,
After being fused and pressurized and fixed, it is discharged out of the apparatus.

On the other hand, the toner remaining on the photosensitive drum 10 without being transferred to the recording paper is cleaned by a cleaning blade 9 which is pressed onto the photosensitive drum 10 in a timely manner.
1 is scraped off by a cleaning device 90 having
After the residual potential is removed by the pre-charging exposure lamp 95,
Enter the next image forming process.

Here, the order of superimposing the yellow, magenta, cyan, and black color images formed on the surface of the photoreceptor may be any order, but at least the second and subsequent developments need to be performed by non-contact development.

[0137]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

"Preparation Example 1 of Non-Spherical Particles""Preparation of Colorant Dispersion Liquid 1"
0.90 kg of Adeka Hope LS-90 (manufactured by Asahi Denka Co., Ltd., sodium n-dodecyl sulfate) and 10.0 l of pure water are added and dissolved by stirring. To this solution, stir the Legal 330R under stirring.
(Carbon black manufactured by Cabot Corporation) 1.20 kg is gradually added, and after the addition, the mixture is stirred well for 1 hour. Next, continuous dispersion was performed for 20 hours using a medium type disperser (sand grinder).

After dispersion, the particle diameter of the dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., and as a result, the weight average diameter was 122 nm. Further, the solid content concentration of the above-mentioned dispersion liquid measured by a gravimetric method by standing drying was 16.6 w / w%. This dispersion is referred to as “colorant dispersion 1”.

"Preparation of Latex-A" (Emulsion Polymerization Step / Low Molecular Weight Component) In a 10 l stainless steel pot, 0.55 kg of sodium dodecylbenzenesulfonate (Kanto Chemical Co., Ltd.) was added, and 4.0 l of ion-exchange pure water was added. And dissolve at room temperature with stirring. This is designated as an anionic surfactant solution A.

In a 10 l stainless steel pot, Newcol 565C (nonionic surfactant: manufactured by Nippon Emulsifier Co.)
0.14 kg, and add 4.0 l of ion-exchanged pure water,
Stir and dissolve at room temperature. This is designated as nonionic surfactant solution B.

223.8 g of potassium peroxodisulfate (manufactured by Kanto Chemical Co., Ltd.) is placed in a 20 l enamel pot, 12.0 l of ion-exchanged water is added, and the mixture is stirred and dissolved at room temperature. This is designated as initiator solution C.

A 100 l GL (glass lining) reactor equipped with a temperature sensor, a cooling pipe,
AX emulsion (emulsion of polypropylene having a number average molecular weight of 3000: solid content concentration of 29.9%) 3.4
1 kg, the anionic surfactant solution A and the nonionic surfactant solution B are added, and stirring is started. Next, 44.0 of ion exchange water is thrown in. Then, styrene 12.1k
g, 2.58 kg of n-butyl acrylate, 1.64 kg of methacrylic acid, and 648 g of TDM (t-dodecyl mercaptan, manufactured by Nippon Thio Chemical Co., Ltd.) are charged in advance by a liquid sending pump over 10 minutes. .

The heating was started, and when the liquid temperature reached 75 ° C., the initiator solution C was added to the liquid sending pump equipped with a quantitative meter for 1 hour.
Add over 00 minutes (average addition rate of polymerization initiator:
1.00 wt% / min).

Thereafter, the liquid temperature was controlled at 75 ° C. ± 1 ° C., and the mixture was heated and stirred for 3 hours.

Further, the liquid temperature was raised to 80 ° C. ± 1 ° C.
Heating and stirring were performed for 3 hours.

The liquid temperature is cooled to 25 ° C. or less, and the stirring is stopped. The mixture was filtered with a filter press, and this was
A.

The resin in this latex had a weight average molecular weight of 131,000, a softening point of 121 ° C., and a glass transition temperature of 5
6 ° C.

"Preparation of Latex-B" (Emulsion Polymerization Step / High Molecular Weight Component) In a 10 l stainless steel pot, 0.55 kg of sodium dodecylbenzenesulfonate (manufactured by Kanto Chemical Co., Ltd.) was added, and 4.0 l of ion-exchanged pure water was added. And dissolve at room temperature with stirring. This is designated as anionic surfactant solution D.

In a 10 l stainless steel pot, Newcol 565C (nonionic surfactant, manufactured by Nippon Emulsifier Co.)
0.14 kg, and add 4.0 l of ion-exchanged pure water,
Stir and dissolve at room temperature. This is designated as a nonionic surfactant solution E.

200.7 g of potassium peroxodisulfate (manufactured by Kanto Chemical Co., Ltd.) is placed in a 20 l enamel pot, 12.0 l of ion-exchanged water is added, and the mixture is stirred and dissolved at room temperature. This is called initiator solution F.

A WAX emulsion (polypropylene emulsion having a number average molecular weight of 3000) was placed in a 100-liter GL reactor (a stirring blade was a Faudler blade) equipped with a temperature sensor, a cooling pipe, a nitrogen introduction device, and a comb baffle.
(9.9%) 3.41 kg, anionic surfactant solution D and nonionic surfactant solution E are added, and stirring is started.
Next, 44.0 of ion exchange water is thrown in.

Heating was started, and when the liquid temperature reached 70 ° C., 11.0 kg of styrene, 4.00 kg of n-butyl acrylate, 1.04 kg of methacrylic acid and TDM (t-dodecyl mercaptan, manufactured by Nippon Thio Chemical Co., Ltd.) ) 9.
02g is previously mixed and charged over 30 minutes. Next, the initiator solution F is added over 60 minutes (average addition rate of the polymerization initiator: 1.67 wt% / min).

Thereafter, the liquid temperature was controlled at 72 ° C. ± 2 ° C., and the mixture was heated and stirred for 4 hours.

The temperature of the liquid is cooled to 30 ° C. or less, and the stirring is stopped. The solution was filtered through a Pall filter, and this filtrate was used as Latex-B.

The resin in this latex had a weight average molecular weight of 231,000, a softening point of 129 ° C., and a glass transition temperature of 5
9 ° C.

(Association fusing step) Sodium chloride (manufactured by Wako Pure Chemical Industries, Ltd., 1
Grade) 5.36 kg and 20.0 l of ion-exchanged water are added and dissolved by stirring. This is designated as sodium chloride solution G.

1.00 g of FC-170C (nonionic surfactant, manufactured by Sumitomo 3M) is placed in a 2 liter glass beaker, and 1.00 liter of ion-exchanged water is added to dissolve with stirring.
This is designated as nonionic surfactant solution H.

The latex-A = 2 prepared above was placed in a 100-liter SUS reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introduction device, and a comb baffle (the stirring blade was an anchor blade).
0.0 kg, latex-B = 5.2 kg, colorant dispersion 1 = 0.4 kg, and ion-exchanged water 20.0 kg are added and stirred. Then, the mixture was heated to 40 ° C., and sodium chloride solution G and isopropanol (Kanto Chemical Co., Ltd., deer first grade)
6.00 kg of nonionic surfactant solution H are added in this order. Then, after leaving it to stand for 10 minutes, the temperature is started to rise to a liquid temperature of 85 ° C. in 60 minutes. Liquid temperature 85 ° C
Heat and stir at ± 2 ° C. for 6 hours for salting out / fusion. Thereafter, the mixture is cooled to 40 ° C. or lower and the stirring is stopped. Aperture 45
The solution is filtered through a sieve of μm, and this filtrate is used as an association liquid.

Then, non-spherical particles in the form of a wet cake were filtered from the association liquid using a Nutsche. afterwards,
It was washed with ion-exchanged water.

The wet cake-shaped non-spherical particles having been washed as described above are taken out from the nutsche, and the whole paper vat 5 is removed.
Spread them into pieces into pieces. After covering with kraft paper, it was dried with a blow dryer at 40 ° C. for 100 hours.

The block-shaped non-spherical particles having been dried were crushed by a Henschel pulverizer.

The non-spherical particles obtained as described above are referred to as “non-spherical particles 1”.

The resin particles had a weight average molecular weight of 58,000, a softening point of 124 ° C., and a glass transition temperature of 56.
° C.

"Production Example 2 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, C.I. I. Pigment Red 122 was used in the same manner to obtain the colored particles of the present invention. The obtained colorant dispersion is referred to as “colorant dispersion 2”, and the non-spherical particles are referred to as “non-spherical particles 2”. The dispersion diameter of the colorant particles was 160 nm.

"Production Example 3 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, C.I. I. Pigment Yellow 17 was used in the same manner as above to obtain colored particles of the present invention. The obtained colorant dispersion is referred to as “colorant dispersion 3”, and the non-spherical particles are referred to as “non-spherical particles 3”. The dispersion diameter of the colorant particles was 130 nm.

"Production Example 4 of Non-spherical Particles" In Production Example 1 of non-spherical particles, C.I. I. Pigment Blue 15: 3 was used in the same manner as above to obtain the colored particles of the present invention. The obtained colorant dispersion is referred to as “colorant dispersion 4”, and the non-spherical particles are referred to as “non-spherical particles 4”. The dispersion diameter of the colorant particles was 90 nm.

"Production Example 5 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, the average addition rate of the polymerization initiator in the production of latex-A was 0.42% by weight per minute (obtained. The resin in the latex had a weight average molecular weight of 2.31.
The softening point was 122 ° C., the glass transition temperature was 58 ° C., and the weight average particle size was 106 nm. ), Latex-B
The average rate of addition of the polymerization initiator was 2.10% by weight per minute (the resin in the obtained latex had a weight average molecular weight =
306,000, softening point = 131 ° C., glass transition temperature = 59
C., weight average particle size = 112 nm. ), Except that the colored particles of the present invention were obtained. The non-spherical particles obtained here are referred to as “non-spherical particles 5”.

The molecular weight of the resin particles was as follows: weight average molecular weight = 89,000, softening point = 126 ° C., glass transition temperature = 58.
° C.

"Production Example 6 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, the average addition rate of the polymerization initiator in the production of latex-A was 1.82% by weight per minute (obtained. The resin in the latex had a weight average molecular weight of 1.91.
The softening point was 123 ° C., the glass transition temperature was 58 ° C., and the weight average particle size was 112 nm. ), Latex-B
The average rate of addition of the polymerization initiator was 0.76% by weight per minute (the resin in the obtained latex had a weight-average molecular weight =
303,000, softening point = 129 ° C, glass transition temperature = 59
° C, weight average particle size = 110 nm. ) To obtain colored particles of the present invention in the same manner. The non-spherical particles obtained here are referred to as “non-spherical particles 6”.

The molecular weight of the resin particles was as follows: weight average molecular weight = 53,000, softening point = 123 ° C., glass transition temperature = 56.
° C.

"Production Example 7 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, the average addition rate of the polymerization initiator in the production of Latex-A was 2.12% by weight per minute (obtained. The resin in the latex had a weight average molecular weight of 1.69.
The softening point was 122 ° C., the glass transition temperature was 58 ° C., and the weight average particle size was 112 nm. ), Latex-B
The average addition rate of the polymerization initiator was 1.30% by weight per minute (the resin in the obtained latex had a weight average molecular weight of
293,000, softening point = 129 ° C., glass transition temperature = 58
° C, weight average particle size = 103 nm. ) To obtain colored particles of the present invention in the same manner. The non-spherical particles obtained here are referred to as “non-spherical particles 7”.

The molecular weight of the resin particles was as follows: weight average molecular weight = 56,000, softening point = 124 ° C., glass transition temperature = 56.
° C.

"Production Example 8 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, the average addition rate of the polymerization initiator in the production of latex-A was 0.14% by weight per minute (obtained. The resin in the latex had a weight average molecular weight of 2.36.
The softening point was 123 ° C., the glass transition temperature was 58 ° C., and the weight average particle size was 112 nm. ), Latex-B
The average addition rate of the polymerization initiator was 0.12% by weight per minute (the resin in the obtained latex had a weight average molecular weight =
310,000, softening point = 132 ° C., glass transition temperature = 59
° C, weight average particle size = 113 nm. ) To obtain colored particles of the present invention in the same manner. The non-spherical particles obtained here are referred to as “non-spherical particles 8”.

The molecular weight of the resin particles was as follows: weight average molecular weight = 688,000, softening point = 129 ° C., glass transition temperature = 58.
° C.

"Production Example 9 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, the average addition rate of the polymerization initiator in the production of latex-A was 4.78% by weight (obtained). The resin in the latex had a weight average molecular weight of 1.21.
The softening point was 121 ° C., the glass transition temperature was 56 ° C., and the weight average particle size was 113 nm. ), Latex-B
The average rate of addition of the polymerization initiator was 4.56% by weight per minute (the resin in the obtained latex had a weight average molecular weight =
230,000, softening point = 128 ° C., glass transition temperature = 58
° C, weight average particle size = 115 nm. ) To obtain colored particles of the present invention in the same manner. The non-spherical particles obtained here are referred to as “non-spherical particles 9”.

The molecular weight of the resin particles was as follows: weight average molecular weight = 56,000, softening point = 123 ° C., glass transition temperature = 56.
° C.

"Production Example 10 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, the polymerizable monomer of latex-A was styrene = 10.8 kg, butyl acrylate = 3.
Resin particles were obtained in the same manner except that 12 kg and methacrylic acid were changed to 2.22 kg. This is latex
A (the resin in the obtained latex had a weight average molecular weight of 210000, a softening point of 126 ° C, a glass transition temperature of 58 ° C, and a weight average particle size of 113 nm). Subsequently, the colored particles of the present invention were obtained using latex-A and latex-B according to Example 1. The non-spherical particles obtained here are referred to as “non-spherical particles 10”. The glass transition temperature of the “non-spherical particles 10” is 56
° C, the softening point was 127 ° C, and the molecular weight distribution was weight average molecular weight = 62,000.

"Production Example 11 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, the polymerizable monomer of latex-B was 12.89 kg of styrene and butyl acrylate
Resin particles were obtained in the same manner except that 3.33 kg and methacrylic acid were changed to 0.89 kg. This was designated as Latex-B (the resin in the obtained latex had a weight average molecular weight of 29,970, a softening point of 128 ° C, a glass transition temperature of 59 ° C, and a weight average particle size of 115 nm. ). Subsequently, the colored particles of the present invention were obtained using latex-A and latex-B according to Example 1. The non-spherical particles obtained here are referred to as “non-spherical particles 11”. The “non-spherical particles 11” had a glass transition temperature of 56 ° C., a softening point of 125 ° C., and a molecular weight distribution of weight average molecular weight = 688,000.

"Preparation Example 12 of Non-Spherical Particles" In Preparation Example 1 of non-spherical particles, the polymerizable monomer of latex-A was 10.11 kg of styrene and butyl acrylate
1.31 kg and acrylic acid were changed to 0.98 kg, and the polymerizable monomer of latex-B was changed to styrene = 11.12.
kg, butyl acrylate = 0.98 kg, acrylic acid =
Resin particles were obtained in the same manner except that the weight was changed to 0.52 kg. This was treated with Latex-A (resin in the obtained latex had a weight average molecular weight of 2.060, and a softening point of 1).
23 ° C., glass transition temperature = 56 ° C., weight average particle size = 11
It was 3 nm. ) And Latex-B (the resin in the obtained latex had a weight average molecular weight of 292,000, a softening point of 130 ° C, a glass transition temperature of 58 ° C, and a weight average particle size of 113 nm). . Then, Example 1
The colored particles of the present invention were obtained using latex-A and latex-B according to the procedure described in Example 1. The non-spherical particles obtained here are referred to as “non-spherical particles 12”. The “non-spherical particles 12” have a glass transition temperature of 55 ° C. and a softening point of 1
At 29 ° C., the molecular weight distribution was such that the weight average molecular weight was 68,000.

"Production Example 13 of Non-Spherical Particles" In Production Example 1 of non-spherical particles, t
-Resin particles were prepared in the same manner except that dodecyl mercaptan was used in an amount of 120 g. This is called latex-C
(Weight average particle size of resin = 116 nm). Except that only this latex-C was used, non-spherical particles were obtained using the same conditions as in the salting out / association fusion of Production Example 1 for non-spherical particles. The obtained non-spherical particles are referred to as “non-spherical particles 1”.
3 ". The glass transition temperature of the “non-spherical particles 13” was 55 ° C., the softening point was 130 ° C., and the molecular weight distribution was weight-average molecular weight = 1380,000.

"Production Example 1 of Non-Spherical Particles for Comparative Example" In Production Example 1 of non-spherical particles, the average addition rate of the polymerization initiator in the production of latex-A was 6.20% by weight per minute.
(The resin in the obtained latex has a weight average molecular weight =
1.030, softening point = 116 ° C., glass transition temperature = 53
° C, weight average particle size = 115 nm. ), The average rate of addition of the polymerization initiator in Latex-B is 5.
3% by weight (the resin in the obtained latex had a weight average molecular weight of 166,000, a softening point of 126 ° C, a glass transition temperature of 58 ° C, and a weight average particle size of 112 nm). Similarly, colored particles for comparison were obtained. The obtained non-spherical particles are referred to as “non-spherical particles for comparison 1”.
The latex obtained in place of latex-A was referred to as “comparison latex-A”, and the latex obtained in place of latex-B was referred to as “comparison latex-A”.
B ". The glass transition temperature of the “non-spherical particles for comparison 1” is 56 ° C., the softening point is 127 ° C., and the molecular weight distribution is
Weight average molecular weight = 56,000, volume average particle size is 6.93μ
m.

"Production Example 2 of Non-Spherical Particles for Comparison" In Production Example 1 of non-spherical particles, the average addition rate of the polymerization initiator in the production of latex-A was 0.05% by weight per minute. Colored particles for comparison were obtained in the same manner except that the average addition rate of the polymerization initiator in -B was changed to 0.03% by weight per minute. The obtained non-spherical particles are referred to as “non-spherical particles for comparison 2”. The latex obtained in place of Latex-A was referred to as “Comparative Latex-
A) and the latex obtained in place of latex-B are referred to as “comparison latex-B”. The glass transition temperature of the resin particles in “Comparative Latex-A” was 5
5 ° C., softening point 122 ° C., molecular weight distribution, weight average molecular weight = 11.910, weight average particle size 112 nm,
The glass transition temperature of the resin particles in “Comparative Latex-B” was 59 ° C., the softening point was 133 ° C., the molecular weight distribution was weight average molecular weight = 23,000, and the weight average particle size was 110 nm. The “non-spherical particles for comparison 2” had a glass transition temperature of 55 ° C., a softening point of 126 ° C., a molecular weight distribution of weight average molecular weight = 275,000, and a volume average particle size of 7.82 μm.
Met.

"Production Example 3 of Non-Spherical Particles for Comparison" In Production Example 1 of non-spherical particles, the polymerization initiator was not added sequentially in the production of latex-A, but was added all at once (average). The addition rate was equivalent to 100% by weight per minute), and the polymerization initiator in Latex-B was not added successively but was added all at once (the average addition rate was equivalent to 100% by weight per minute). Similarly, colored particles for comparison were obtained. The non-spherical particles obtained here are referred to as “non-spherical particles for comparison 3”. The latex obtained in place of latex-A is referred to as “comparison latex-A”, and the latex obtained in place of latex-B is referred to as “comparison latex-B”. The glass transition temperature of the resin particles in “Comparative Latex-A” was 53 ° C., the softening point was 112 ° C., and the molecular weight distribution was weight average molecular weight = 1.02.
10,000, the weight average particle size is 113 nm, the glass transition temperature of the resin particles in “Comparative Latex-B” is 53 ° C.,
The softening point was 130 ° C., and the molecular weight distribution was weight average molecular weight = 1.
The weight average particle diameter was 66,000. Also,
The glass transition temperature of the “non-spherical particles for comparison 3” is 53 ° C.
The softening point is 122 ° C and the molecular weight distribution is weight average molecular weight 5.
30,000, and the volume average particle size was 9.51 μm.

<< Evaluation Method (Physical Properties / Characteristics) >> The above “non-spherical particles 1” to “non-spherical particles 13”, “non-spherical particles for comparison 1” to “non-spherical particles for comparison 3” , Particle size and shape were evaluated. For the shape, using a photo magnified 1000 times with a scanning electron microscope,
The uniformity of the shape was visually evaluated.

Regarding the particle size, the volume average particle size D ₅₀ and the particle size distribution CV were measured using a laser diffraction type particle size measuring device / SLAD1100 manufactured by Shimadzu Corporation. The particle size distribution CV is the standard deviation (D ₅₀ ) / D ₅₀ , and a smaller value indicates a narrower particle size distribution.

[0187]

[Table 1]

<< Print Evaluation >> The above “non-spherical particles 1” to
"Non-spherical particles 13" and "Non-spherical particles 1 for comparison"
1% by weight of hydrophobic silica (primary average particle diameter = 12 nm) was added to “Comparative non-spherical particles 3” to obtain a toner. These toners are referred to as “toner 1” to “toner 13” and “comparative toner 1” to “comparative toner 3”, respectively.

Further, a developer having a toner concentration of 6% was prepared by mixing these toners and a ferrite carrier coated with a styrene acrylic resin and having a volume average particle diameter of 45 μm, and used for printing evaluation. These developers are referred to as “developer 1” to “developer 12” and “comparative developer 1” to “comparative developer 3”, respectively, corresponding to the toner.

Evaluation (Non-Contact Developing Method) In the evaluation, a Konica color copier 9028 was modified and used. The conditions are as shown below. A laminated organic photoreceptor was used as the photoreceptor.

Photoreceptor surface potential = -550 V DC bias = -250 V AC bias = Vp-p: -50 to -450 V Alternating electric field frequency = 1800 Hz Dsd = 300 μm Pressing force = 10 gf / mm Pressing bar = SUS416 (magnetic stainless steel) Made) /
Diameter 3 mm Developer layer thickness = 150 μm Developing sleeve = 20 mm As a fixing method, a method of using a hot roll fixing method and cleaning the untransferred toner remaining on the photoreceptor by a blade cleaning method was adopted.

The transfer paper used was a paper having a continuous weight of 55 kg, and an image was formed in the vertical direction. The image formation was performed in a normal temperature and normal humidity environment (25 ° C./55% RH). As the evaluation items, the sharpness of the image due to the reproducibility of the fine line was evaluated. This evaluation is based on the number of fine lines that can be reproduced per 1 mm, and was evaluated for both vertical and horizontal thin lines. The images were compared with a 10-fold loupe, and the maximum number per 1 mm that could be determined in a state where lines were formed continuously without intermittent lines was compared.

[0193] Using a 5% pixel rate image, 1
The printing of 100,000 sheets was performed in a normal temperature and normal humidity environment, and the same evaluation was performed for the image after 100,000 sheets. Further, the presence or absence of odor at the fixing site was continuously determined by sensory evaluation. The sensory evaluation was performed by using 10 observers, performing continuous printing of 1,000 sheets in a room without air circulation, and evaluating how many persons felt odor. The results are shown below.

[0194]

[Table 2]

Evaluation (Contact Developing Method) A digital copying machine 7050 manufactured by Konica was remodeled and evaluated for actual photography. The conditions are as shown below. A laminated organic photoreceptor was used as the photoreceptor.

Photoconductor surface potential = −700 V DC bias = −500 V Dsd = 600 μm Developer layer regulation = Magnetic H-Cut method Developer layer thickness = 700 μm Developing sleeve diameter = 40 mmφ As a fixing method, hot roll fixing is used. A method of cleaning the untransferred toner remaining on the photoreceptor by a blade cleaning method was employed.

The transfer paper used was a paper having a continuous weight of 55 kg, and an image was formed in the vertical direction. The image formation was performed in a normal temperature and normal humidity environment (25 ° C./55% RH). As the evaluation items, the sharpness of the image due to the reproducibility of the fine line was evaluated. This evaluation is based on the number of fine lines that can be reproduced per 1 mm, and was evaluated for both vertical and horizontal thin lines. The images were compared with a 10-fold loupe, and the maximum number per 1 mm that could be determined in a state where lines were formed continuously without intermittent lines was compared.

The results are shown below.

Further, using an image with a 5% pixel rate, one
The printing of 100,000 sheets was performed in a normal temperature and normal humidity environment, and the same evaluation was performed for the image after 100,000 sheets. Further, the presence or absence of odor at the fixing site was continuously determined by sensory evaluation. The sensory evaluation was performed by using 10 observers, performing continuous printing of 1,000 sheets in a room without air circulation, and evaluating how many persons felt odor. The results are shown below.

[0200]

[Table 3]

As shown in the above results, the toner of the present invention is excellent in transferability and can maintain high image quality for a long time. Further, it is understood that the toner does not generate an unpleasant odor in the fixing portion and does not cause a problem in use.

According to the present invention, at the time of association, polymerized toner particles having a uniform particle size and surface state can be obtained, so that good transferability can be obtained, and as a result, a high quality electrophotographic image can be obtained.

[0203]

According to the present invention, a toner having improved transferability for developing an electrostatic latent image, a method for producing the toner, a developer using the toner and an electrophotographic image forming method can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a developing device (developing device) used in the image forming method of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of an image forming apparatus used in the image forming method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor drum (image forming body) 11 conductive substrate 12 photosensitive layer 20 scorotron charger 25 image reading unit 30 image writing unit 40A, 40B, 40C, 40D developing device (developing device) 41 developing sleeve (developer conveying member) 42 magnet body 45 supply roller 46 regulating rod 47 scraper 48 stirring roller 49 casing 50 two-component developer 51 power supply 60 paper supply unit 61 first paper supply roller 62 second paper supply roller 70 transfer corona charger 75 separation corona charger Container 80 Conveying Unit 85 Fixing Unit 90 Cleaning Device 91 Cleaning Blade 95 Pre-Charging Exposure Lamp

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Asao Matsushima 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AA01 AA02 AB06 CA04 EA07 FA06 2H077 AB11 AC01 AC04 AD06 AD13 AD17 AD32 AD36 EA03 EA14 EA16 GA13

Claims (8)

[Claims] In a toner for developing an electrostatic latent image in which at least resin particles and colorant particles are salted out and fused, the resin particles emulsify a polymerizable monomer constituting the resin particles. A toner for developing an electrostatic latent image, which is a resin particle obtained by a polymerization method in which a polymerization initiator is added to an aqueous medium at an average addition rate A described below. (0.1 wt% / min of the total weight of the polymerizable monomer used) ≦
(Average addition rate A) ≦ (5 of the total weight of the polymerizable monomer used)
wt% / min) 2. The electrostatic latent image developing toner according to claim 1, wherein the average addition speed A is as follows. (0.3 wt% / min of the total weight of the polymerizable monomer used) ≦
(Average addition rate A) ≦ (3 of the total weight of the polymerizable monomer used)
wt% / min) 3. A method for producing a toner for developing an electrostatic latent image having at least resin particles and colorant particles, wherein the resin particles are prepared by emulsifying a polymerizable monomer constituting the resin particles. A method for producing a toner for developing an electrostatic latent image, comprising subjecting a resin particle and a colorant particle obtained by a polymerization method wherein a polymerization initiator is added at the following average addition rate A to salting out and fusing. (0.1 wt% / min of the total weight of the polymerizable monomer used) ≦
(Average addition rate A) ≦ (5 of the total weight of the polymerizable monomer used)
wt% / min) 4. The method for producing a latent electrostatic image developing toner according to claim 3, wherein the average addition speed A is as follows. (0.3 wt% / min of the total weight of the polymerizable monomer used) ≦
(Average addition rate A) ≦ (3 of the total weight of the polymerizable monomer used)
wt% / min) 5. A method for developing an electrostatic latent image developing toner in which at least resin particles and colorant particles are salted out and fused, and a developer having magnetic particles, wherein the resin particles constitute the resin particles. A developer comprising resin particles obtained by a polymerization method in which a polymerization initiator is added at an average addition rate A described below to an aqueous medium in which a monomer is emulsified. (0.1 wt% / min of the total weight of the polymerizable monomers used) ≦ (average addition rate A)
≤ (5 wt% / min of the total weight of the polymerizable monomer used) 6. The developer according to claim 5, wherein the average addition speed A is as follows. (0.3 wt% / min of the total weight of the polymerizable monomer used) ≦
(Average addition rate A) ≦ (3 of the total weight of the polymerizable monomer used)
wt% / min) 7. The latent image formed on the electrostatic latent image forming body is developed with a developer having at least a toner for developing an electrostatic latent image, and then transferred to an image support and thermally fixed to form an image. In the obtained image forming method, the toner is an electrostatic latent image developing toner in which at least resin particles and colorant particles are salted out and fused, and the resin particles are polymerizable monomers constituting the resin particles. Resin particles obtained by a polymerization method in which a polymerization initiator is added to an aqueous medium in which a monomer is emulsified at an average addition rate A described below, and is used for developing an electrostatic latent image remaining on the electrostatic latent image forming body. An image forming method comprising cleaning a toner. (0.1 wt% / min of the total weight of the polymerizable monomer used) ≦
(Average addition rate A) ≦ (5 of the total weight of the polymerizable monomer used)
wt% / min) 8. The image forming method according to claim 7, wherein the average addition speed A is as follows. (0.3 wt% / min of the total weight of the polymerizable monomer used) ≦
(Average addition rate A) ≦ (3 of the total weight of the polymerizable monomer used)
wt% / min)