JPH09258472A - Electrostatic charge image developing toner and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrostatic charge image developing toner which has excellent uniform electrification property, improved stability in electrification property for repeated use and excellent productivity with little fog and splashing, by using a specified polymn. initiator to form a coating layer. SOLUTION: The particle of this electrostatic charge image developing toner has a coating layer on a polymer particle. The coating layer is formed by using a polymn. initiator expressed by formula. By this method, the azo polymn. initiator used has a certain or more degree of carbon chains and polar groups. Namely, an azo polymn. initiator generally has such a property that it is bonded to the molecular end of the polymer chain after the polymn., and the polymn. initiator of this method has an effect as a surfactant in the initial stage and a function to stabilize the monomers added. Moreover, the initiator can give polar groups to the both ends of the polymer chain and has a function to enhance the stability on the interface of the coated particle. By using this initiator, uniform and stable electrification can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in a method for developing an electrostatic latent image and a method for producing the toner.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, U.S. Pat. No. 2,297,691 and JP-B-42-23910 are known.
Although many methods are known as described in JP-A-43-24748 and JP-A-43-24748, generally, a photoconductive substance is used and an electric latent image is formed on a photoreceptor by various means. After forming the latent image, the latent image is developed with a toner, and if necessary, the toner image is transferred to a transfer material such as paper and then fixed by heating, pressure, solvent vapor or the like to obtain a copied image. .

As a method of developing with toner or a method of fixing a toner image, various methods have been conventionally proposed, and methods suitable for respective image forming processes have been adopted.

Conventionally, the toner used for these purposes is generally a toner having a desired particle diameter by a fine pulverizer and a classifier after melt-mixing a coloring agent consisting of a dye and a pigment in a thermoplastic resin and uniformly dispersing them. Has been manufactured.

While this method of manufacture can produce fairly good toners, it does have certain limitations, ie, the choice of toner materials. For example, the resin colorant dispersion must be sufficiently brittle and capable of being pulverized in economically feasible manufacturing equipment. However, if the resin colorant dispersion is made brittle in order to satisfy these requirements, the particle size range of the particles formed when actually pulverized at high speed tends to be wide,
In particular, a problem arises that a relatively large proportion of fine particles is contained in this. Further, such a highly brittle material is susceptible to further pulverization or pulverization when used for development in a copying machine or the like. Further, with this method, it is difficult to disperse solid fine particles such as a colorant into the resin completely and uniformly. Depending on the degree of dispersion, fog increases, image density decreases, and color mixing / transparency Care must be taken in dispersion as it causes defects. Further, exposure of the coloring agent to the fracture surface may cause fluctuations in development characteristics.

On the other hand, in order to overcome the problems of the toner caused by these pulverization methods, Japanese Patent Publication Nos.
JP-A-3-10799 and JP-A-51-14895 have proposed a method for producing a toner by a suspension polymerization method. In the suspension polymerization method, a polymerizable monomer, a colorant,
A polymerization initiator and, if necessary, a cross-linking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a monomer composition, and the monomer composition contains a dispersion stabilizer. The particles are dispersed in a continuous phase, for example, an aqueous phase using a suitable stirrer, and a polymerization reaction is simultaneously performed to obtain toner particles having a desired particle size.

Since this method does not include a crushing step at all, the toner does not need to be brittle, a soft material can be used, and the colorant is not exposed on the surface of the particles. It has the advantage of having excellent triboelectric charging properties. Further, since the classification step can be omitted, there are great cost reduction effects such as energy saving, shortening of manufacturing time, and improvement of process yield.

However, in the case of such a polymerization method toner having a fine particle diameter, the colorant is exposed to or close to the toner surface layer as compared with the toner having a large particle diameter, so that the influence of the colorant is likely to occur, and thus the charging uniformity is uniform. It has become clear that

This phenomenon becomes remarkable when the number of printings of the copying machine is repeated under high humidity. Conventionally, in order to make the charging uniform, for example, JP-A-62-73277, JP-A-3-35660, etc., a method of coating a so-called toner surface layer with a resin has been proposed.

However, in these methods, since the coating layer is thick, the influence of the coloring agent can be prevented, but
Since almost no component having charge controllability can be contained, there has been a problem that the absolute value of the charge amount becomes small.

Further, in order to improve this problem, Japanese Patent Laid-Open No. 62-73277, which focuses on mixing a charge control agent into a coating resin layer, considers the durability of the fine particle toner, and therefore, the copying When the number of impressions is repeated, the charge control agent is likely to be exposed on the toner surface as in the case of the colorant.

Therefore, a method of coating the surface of the polymer particles in multiple stages is disclosed in JP-A-64-62666 and JP-A-6-66266.
4-63035, Japanese Patent Publication No. 58-57105, etc., but the manufacturing process is complicated,
It is a cost disadvantage.

Further, in recent years, digital full-color copying machines and printers have been put on the market, and it has become possible to obtain not only resolution and gradation but also high image quality excellent in color reproducibility without color unevenness.

In a digital full-color machine, a color image original is color-separated by B (blue), G (green), and R (red) filters, and then a latent image having a dot diameter of 20 to 70 μm corresponding to the original image. Is developed using the subtractive color mixing action using each color developer of Y (yellow), M (magenta), C (cyan), and Bk (black). It is expected that there will be a need to transfer to a transfer material, and further a demand for a finer particle size of a developer corresponding to a fine dot in order to cope with higher image quality in the future.

Further, in the future as printers and copiers become faster and full-colored, further improvement in low-temperature fixability becomes an important factor. From this point as well, the particle size distribution is sharp and the fine particle size is small. The polymerization methods by which the developer can be produced exhibit excellent properties. Toners mounted on a full-color copying machine are required to sufficiently mix multicolor toners in a fixing process, and it is essential to improve color reproducibility and transparency of OHP images at this time. Further, as the color toner, a resin having a low molecular weight, which has a better melting property than that of the black toner, is usually required.

Further, for the general black toner, a releasing agent having a relatively high crystallinity represented by polyethylene wax or polypropylene wax is used for the purpose of improving the high temperature offset resistance at the time of fixing.

However, in the full-color toner, the crystallinity of the release agent is high, so that the transparency is remarkably hindered when outputting to the OHP.

Therefore, by normally applying silicone oil or the like to the heat fixing roller without adding a releasing agent as a constituent of the color toner, the high temperature offset resistance is improved as a result.

However, the output transfer material thus obtained is not preferable because extra silicone oil or the like adheres to the surface of the output transfer material, causing discomfort when the user handles it.

For this reason, a developer for oilless fixing in which a large amount of a low softening point substance is contained in the developer has been studied, but it has excellent low temperature fixing property and transparency, and at the same time has high temperature offset resistance. No developer showing the above has been obtained yet.

[0021]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a toner for developing an electrostatic charge image and a method for producing the same, which solves the above-mentioned problems of the prior art.

That is, an object of the present invention is to provide an electrostatic charge image developing toner excellent in uniform charging property, less fog and scattering, improving stability of charging property in durability and excellent in manufacturability, and a manufacturing method thereof. To provide.

[0023]

The present invention provides a toner for developing an electrostatic image having a coating layer on polymer particles, wherein the coating layer has the following formula:

[0024]

Embedded image The present invention relates to a toner for developing an electrostatic charge image, which is a coating layer formed by using a polymerization initiator represented by the above, and a method for producing the toner.

The inventors of the present invention do not prevent the fine irregularity of the toner surface property from being disturbed by a thick coating as in the conventional invention, but only make the surface property uniform by a minimum coating. Focused on good things. It is self-evident that the thinner the coating layer is, the more important the coating uniformity on the resin particles becomes. However, the present inventors have studied in this regard, and have set the carbon chain and the polar group to a certain degree or more. It was found that by using the azo-based polymerization initiator, the coating stability can be further increased, a thin layer can be coated, and the charging uniformity and stability can be obtained.

That is, the azo-based polymerization initiator has the property of being bonded to the end of the polymer chain after the polymerization, but the polymerization initiator of the present invention has a surface-active effect at the initial stage and therefore stabilizes the added monomer. It has a function of converting the compound to a polar group at both ends of the polymer chain after polymerization, and thus has a function of amplifying stability at the interface of the coated particles.

Therefore, the inventors of the present invention have found that the above-mentioned initiator can be used to further stabilize the coating and make the charging property uniform and stable.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer particles used in the present invention are generally emulsion polymerization method, suspension polymerization method, interfacial polymerization method, salting-out polymerization method, association polymerization method, mechanical pulverization method of resin pieces, spray drying. Any production method may be used as long as it is obtained by a known polymer or a method for producing resin particles. In the coating step, a resin produced by a so-called polymerization method such as an emulsion polymerization method, a suspension polymerization method, an interfacial polymerization method, a salting-out polymerization method, and an association polymerization method which are manufactured in advance in a uniform aqueous medium, It is preferable because the manufacturing can be simplified. Particularly in the present invention, it is preferable to use a known seed polymerization method, emulsion polymerization method, association polymerization method, or salting-out polymerization method as the coating step.

The polymerizable monomer that can be used in the polymer particles is a styrene-based monomer such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene or p-ethylstyrene. Body, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate,
Acrylic esters such as n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, Methacrylic acid n-
Methacrylic acid esters such as butyl, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, ethylaminoethyl methacrylate,
Other examples include monomers such as acrylonitrile, methacrylonitrile and acrylamide.

These monomers may be used alone or in combination. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in a mixture with another monomer, from the viewpoint of the developing characteristics and durability of the toner.

In the present invention, it is more preferable to add a polymer / copolymer having a polar group as an additive to the above monomer system for polymerization. Since the polar polymer / copolymer gathers on the surface layer of the toner particles, it forms a kind of shell-like form and imparts excellent properties such as blocking resistance to the toner particles, while By polymerizing so as to contribute to the improvement of fixing characteristics with a relatively low molecular weight,
It is possible to obtain a toner that satisfies the conflicting requirements of fixability and blocking resistance. The polar polymers / copolymers that can be used in the present invention are exemplified below.

Polymers of nitrogen-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate or copolymers with styrene / unsaturated carboxylic acid ester, nitrile monomers such as acrylonitrile, vinyl chloride and the like. Halogen-containing monomers, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, other unsaturated dibasic acids,
Unsaturated dibasic acid anhydrides, polymers such as nitro monomers or copolymers with styrene monomers, polyesters,
Epoxy resin etc. are mentioned.

The amount of the polar polymer / copolymer added is 0.1 to 1 with respect to 100 parts by weight of the polymerizable monomer.
0 parts by weight is preferred.

As the colorant used in the polymer particles of the present invention, known colorants can be used. Examples thereof include carbon black and iron black, and C.I. I. Direct Red 1, C.I.
I. Direct Red 4, C.I. I. Acid Red 1,
C. I. Basic Red 1, C.I. I. Modan Red 30, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I.
I. Basic Blue 5, C.I. I. Modan blue 7,
C. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6, yellow lead, cadmium yellow, mineral fast yellow,
Navel Yellow, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG, Tartrazine Lake, Molybdenum Orange, Permanent Orange GT
R, benzidine orange G, cadmium red, permanent red 4R, watching red calcium salt,
Brilliant Carmine 3B, Fast Violet B,
There are dyes such as methyl violet red lake, dark blue, cobalt blue, alkali blue lake, Victoria blue lake, quinacridone, rhodamine lake, phthalocyanine blue, fast sky blue, pigment green B, malachite green lake, and final yellow green G. In the present invention, since a toner is obtained by using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant, and preferably surface modification, for example,
It is better to apply a hydrophobic treatment with a substance that does not inhibit polymerization. In particular, since many dyes and carbon black have a polymerization inhibitory property, caution is required when using them. As a preferable method for surface-treating the dye system, there is a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance, and the obtained colored polymer is added to the monomer system. Further, carbon black may be subjected to a treatment similar to the above dye, or a graft treatment with a substance that reacts with the surface functional group of carbon black, such as polyorganosiloxane.

When the toner is used as a magnetic toner, it may contain magnetic powder. As such magnetic powder, a substance that is magnetized when placed in a magnetic field is used.
There are powders of ferromagnetic metals such as iron, cobalt and nickel, and compounds such as magnetite and ferrite. In particular, in the present invention, since a toner is obtained by using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the magnetic material, and preferably surface modification, for example, there is no polymerization inhibitory property. It is better to give a hydrophobic treatment with a substance.

The more preferable polymer particles used in the present invention include a low softening point substance such as a hydrocarbon compound, which is generally used as a releasing agent, for the purpose of improving the releasing property at the time of heat roll fixing. It contains 30% by weight, and the low softening point substance is further measured by a tomographic plane measuring method using a transmission electron microscope (TEM).
It is produced by using a direct polymerization method in which an outer shell resin layer is included.

From the viewpoint of fixability, it is necessary to incorporate a large amount of the low softening point substance into the polymer particles or the toner, so that the low softening point substance must necessarily be encapsulated in the outer shell resin. Polymer particles or toner when not encapsulated,
Unless special freezing and pulverization is used in the pulverization step, sufficient pulverization cannot be achieved, and as a result, only particles having a wide particle size distribution can be obtained, and toner fusion to the apparatus also occurs, which is extremely undesirable.
Further, in the freeze-pulverization, the device becomes complicated to prevent dew condensation on the device, and if the toner absorbs moisture, the workability of the toner is reduced, and it is necessary to additionally add a drying step, which causes a problem. As a specific method for encapsulating the low softening point substance, the polarity of the material in the aqueous medium is set to be smaller for the low softening point substance than the main monomer, and a small amount of a resin or monomer having a large polarity is used. Polymer particles or toner having a so-called core-shell structure in which the low softening point substance is coated with the outer shell resin can be obtained by adding The particle size distribution control and particle size control of polymer particles or toners are carried out by changing the kind or amount of the poorly water-soluble inorganic salt or dispersant acting as a protective colloid, or mechanical device conditions such as the peripheral speed of the rotor, The predetermined polymer particles or toner of the present invention can be obtained by controlling the number of passes, the stirring conditions such as the shape of the stirring blade, the shape of the container, or the concentration of the solid content in the aqueous solution.

In the present invention, as a specific method for measuring the tomographic plane of the polymer particles or the toner, it is possible to sufficiently disperse the toner in an epoxy resin which is curable at room temperature and then cure it in an atmosphere at a temperature of 40 ° C. for 2 days. The cured product is dyed with ruthenium tetroxide and, if necessary, osmium tetroxide in combination, and then a flaky sample is cut out using a microtome equipped with diamond teeth to obtain a transmission electron microscope (TEM).
Was used to measure the tomographic morphology of the toner. In the present invention, it is preferable to use the ruthenium tetroxide dyeing method in order to make a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell. A typical example is shown in FIG. It was clearly observed that the low softening point substance was encapsulated by the outer shell resin.

As the low softening point substance used in the present invention, a compound having a main component maximum peak value measured according to ASTM D3418-8 of 40 to 90 ° C. is preferable. When the maximum peak is less than 40 ° C., the self-aggregating force of the low softening point substance is weakened, resulting in low high temperature offset resistance, which is not preferable especially for full color toner. On the other hand, if the maximum peak exceeds 90 ° C., the fixing temperature becomes high, and it becomes difficult to appropriately smooth the surface of the fixed image, which is not preferable in terms of color mixing. Further, when the toner is obtained by the direct polymerization method, the temperature of the maximum peak value is high because the granulation and the polymerization are carried out in an aqueous system, so that the low softening point substance mainly precipitates during the granulation and hinders the suspension system. Therefore, it is not preferable.

In measuring the temperature of the maximum peak value of the present invention,
For example, DSC-7 manufactured by PerkinElmer is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. For the sample, an aluminum pan was used and an empty pan was set as a control, and the temperature rising rate was 10 ° C./min. Was measured.

Specifically, paraffin wax, polyolefin wax, Fischer-Tropish wax,
Amide wax, higher fatty acid, ester wax and their derivatives or their graft / block compounds can be used. Particularly, in the present invention, an ester wax having one or more long-chain ester moieties having 10 or more carbon atoms represented by the following general structural formula has an effect on high temperature offset resistance without impairing transparency of OHP. preferable. The structural formulas of typical compounds of specific ester waxes preferable in the present invention are shown below as general structural formulas, general structural formulas and general structural formulas.

[0042]

Embedded image

[In the formula, a and b represent an integer of 0 to 4,
a + b is 4, R ₁ and R ₂ represent an organic group having 1 to 40 carbon atoms, and a group having a carbon number difference between R ₁ and R ₂ of 10 or more, and n and m are 0 to 0. Indicates an integer of 15, n and m
Cannot be 0 at the same time. ]

[0044]

Embedded image

[In the formula, a and b represent an integer of 0 to 4,
a + b is 4, R ₁ represents an organic group having 1 to 40 carbon atoms, n and m represent integers of 0 to 15, and n and m do not become 0 at the same time. ]

[0046]

[Chemical 6]

[In the formula, a and b represent an integer of 0 to 3,
a + b is 3 or less, and R ₁ and R ₂ have 1 to 40 carbon atoms
And an organic group having a carbon number difference of 10 or more between R ₁ and R ₂ , R ₃ is an organic group having 1 or more carbon atoms, and n and m are integers from 0 to 15. As shown, n and m are never 0 at the same time. ]

The ester wax preferably used in the present invention preferably has a hardness of 0.5 to 5.0.
The hardness of the ester wax is 20 mmφ in diameter and 5 in thickness.
It is a value obtained by measuring the Vickers hardness using, for example, a dynamic ultra-micro hardness meter (DUH-200) manufactured by Shimadzu Corporation after manufacturing a sample having a cylindrical shape of mm. The measurement conditions are
Vickers hardness is obtained by displacing 10 μm under a condition of a load rate of 9.67 mm / sec with a load of 0.5 g and holding it for 15 seconds, measuring the obtained dent shape. The hardness of the ester wax preferably used in the present invention is 0.5 to 5.0.
Shows the value of If the material has a hardness of less than 0.5 and has a low softening point, the pressure dependency and the process speed dependency of the fixing device become large, and the high temperature offset resistance effect is apt to be insufficiently expressed. Since the stability is poor and the self-cohesive force of the release agent itself is small, the high temperature offset resistance effect is likely to be insufficient. Specific compounds include the following compounds.

[0049]

Embedded image

In recent years, the need for full-color double-sided images has been increasing, and in forming a double-sided image, the toner image on the transfer paper first formed on the front surface is fixed even when the image is formed next on the rear surface. There is a possibility of passing through the heating part of the container again, and it is necessary to more fully consider the high temperature offset resistance of the toner. Therefore, in the present invention, it is essential to add a large amount of the low softening point substance. Specifically, the low softening point substance is preferably added to the toner in an amount of 5 to 30% by weight. Addition of less than 5% by weight does not show sufficient high-temperature offset resistance, and the image on the back side tends to show an offset phenomenon when fixing a double-sided image. On the other hand, if it exceeds 30% by weight, coalescence of the toner particles is likely to occur during granulation in the production by the polymerization method, and particles having a wide particle size distribution are likely to be produced, which is not suitable for the present invention.

In the present invention, it is preferable to add a charge control agent to the polymer particles for the purpose of controlling the chargeability of the toner.

As these charge control agents, among known ones, those having almost no polymerization inhibitory property or water phase transfer property are used. For example, as positive charge control agents, nigrosine dyes, triphenylmethane dyes, quaternary compounds are used. Examples thereof include ammonium salts, guanidine derivatives, imidazole derivatives, amine compounds, and the like. As negative charge control agents, metal-containing salicylic acid compounds, metal-containing monoazo dye compounds, urea derivatives, styrene-acrylic acid copolymers, styrene- Methacrylic acid copolymers may be mentioned.

The amount of these charge control agents added is preferably 0.1 to 10% by weight of the polymerizable monomer.

As the polymerization initiator used for the polymerization of the polymer particles in the present invention, any suitable polymerization initiator, for example, 2,2'-azobis- (2,4-divaleronitrile), 2,2 '-Azobisisobutyronitrile, 1,
Azo-based or diazo-based polymerization initiators such as 1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; Examples thereof include peroxide type polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyloxy carbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide.

These polymerization initiators are preferably added in an amount of 0.5 to 20% by weight of the polymerizable monomer, and they may be used alone or in combination.

In the present invention, in order to control the molecular weight of the polymer particles, known crosslinking agents and chain transfer agents may be added, and the preferable addition amount is 0.001 of the polymerizable monomer. ~ 15% by weight.

The coating step used in the present invention is a known coating method such as a seed polymerization method; JP-A-57-455.
Known methods such as a method of adding a resin emulsion to polymer particles and adhering and mixing the resin emulsion as described in JP-A-58, etc., a resin precipitation method used for so-called capsule toners can be used.

Examples of the polymerizable monomer used in the coating step of the present invention include styrenes such as styrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, p-methoxystyrene and p-ethylstyrene. Monomers, acrylic acid, methacrylic acid, and methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate , Acrylates such as stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate. , Dodecyl methacrylate, methacrylic acid 2-ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, methacrylic acid esters such as diethylaminoethyl methacrylate and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide.

These monomers may be used alone or in combination. Among the above monomers, using styrene or a styrene derivative alone or in admixture with other monomers enhances the adsorptivity to the polymer particles, and enhances the blocking resistance and durability. preferable.

A crosslinking agent may be added to the monomer used in the coating step of the present invention in order to further impart blocking resistance and the like.

As the crosslinking agent used in the present invention, any known crosslinking agent can be used. The cross-linking agent preferably used is a compound mainly having two or more polymerizable double bonds, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene and derivatives thereof; for example, ethylene glycol dimethacrylate, diethylene glycol. Methacrylate,
Triethylene glycol methacrylate, trimethylolpropane triacrylate, allyl methacrylate,
Diethylenic carboxylic acid esters such as t-butylaminoethyl methacrylate, tetraethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, etc .; N, N-divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc. All divinyl compounds, compounds having three or more vinyl groups, etc. may be used alone or as a mixture.

Furthermore, ethylene glycol, triethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A , Polyoxypropyleneized bisphenol A and other dihydric alcohols; maleic acid, fumaric acid, mesaconinic acid, citraconic acid,
Itaconic acid, glutaconic acid, phthalic acid, isophthalic acid,
Dibasic acids and their derivatives such as terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, their anhydrides or their esters with lower alcohols; glycerin, trimethylolpropane, pentaerythritol, etc. Trivalent or higher alcohols; and trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid are used in the present invention as a crosslinking agent.

The amount of the crosslinking agent added to the monomer is 0.005 to 20 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the monomer.

If the amount of addition is too large, it will not melt and
The fixability of the toner is impaired. On the other hand, if the amount is too small, it becomes difficult to impart properties such as durability and storability of the toner.

Regarding the polymerization initiator in the coating step of the present invention, the azo initiator having a certain amount of carbon chains and polar groups has a function of stabilizing the added monomer because it has a surface-active effect in the initial stage of the coating step. And having polar groups at both ends of the polymer chain after polymerization, it has the function of amplifying the stability at the interface of the coated particles. Furthermore, a thin coating layer is obtained, and the uniformity and stability of charging are improved. This effect becomes remarkable especially in negative charging. Therefore, even if the addition amount at the time of coating is small, coating stability higher than that of the conventional initiator can be obtained.

In consideration of the effect of surface activity, storage stability, etc., a polymerization initiator having the following structure is used in the coating step of the present invention.

[0067]

Embedded image

When n exceeds 0 or 2 in the above formula [A] or [B], there is substantially no surfactant effect, and the same effect as other polymerization initiators is obtained. Moreover, when m exceeds 0 or 3, storage stability becomes poor.

The amount of the above initiator added is 0.1 to 10 relative to the polymerizable monomer in order to avoid the risk of self-emulsification.
Wt% is preferable, alone or a known polymerization initiator,
For example, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile,
1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-
Azo- or diazo-type polymerization initiators such as dimethylvaleronitrile and azobisisobutyronitrile; peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy carbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide It can be used in combination with a system polymerization initiator.

The additives used in the present invention for imparting various characteristics are 1/1 times the volume average diameter of the toner particles from the viewpoint of durability in the toner or when added to the toner.
The particle size is preferably 0 or less. The particle size of the additive means an average particle size obtained by observing the surface of the toner particles with an electron microscope. As additives for the purpose of imparting these properties, for example, the following are used.

1) Flowability-imparting agents: metal oxides (silicon oxide, aluminum oxide, titanium oxide, etc.), carbon black, fluorinated carbon, etc. Those subjected to a hydrophobic treatment are more preferable.

2) Abrasive: metal oxide (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitride (silicon nitride, etc.), carbide (silicon carbide, etc.), metal salt (calcium sulfate, etc.) , Barium sulfate, calcium carbonate, etc.) etc.

3) Lubricants: Fluorine-based resin powders (vinylidene fluoride, polytetrafluoroethylene, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.), etc.

4) Charge controllable particles: metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide, etc.), carbon black, etc.

These additives are used in an amount of 0.1 to 10 parts by weight, preferably 100 parts by weight of the toner particles.
0.1 to 5 parts by weight are used. These additives may be used alone or in combination of two or more.

Any suitable stabilizer is added to the dispersion medium used in the present invention. For example, as the inorganic compound, calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide,
Examples thereof include aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica and alumina. As the organic compound, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and its salts, starch and the like can be used by dispersing them in an aqueous phase. It is preferable to use 0.2 to 20 parts by weight of these stabilizers with respect to 100 parts by weight of the polymerizable monomer.

When an inorganic compound is used among these dispersion stabilizers, a commercially available product may be used as it is, but the inorganic compound may be produced in an aqueous medium in order to obtain finer particles. . For example, in the case of calcium phosphate,
It is advisable to mix the sodium phosphate aqueous solution and the calcium chloride aqueous solution under high stirring.

Further, 0.001 to 0.1 part by weight of a surfactant may be used for finely dispersing these stabilizers. This is for promoting the intended action of the dispersion stabilizer, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate,
Examples include sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like.

The polymerized toner used in the present invention is obtained by the following method. That is, a releasing agent, a colorant, a charge control agent, a polymerization initiator, and other additives are added to a polymerizable monomer, and the monomer composition is uniformly dissolved or dispersed by a homogenizer or an ultrasonic disperser. In a water-based medium containing a dispersion stabilizer, a normal stirrer or homomixer
Disperse with a homogenizer. Preferably the monomer composition droplets are of the desired toner particle size, generally 30.
Granulate by adjusting the stirring speed and time so as to have a particle size of μm or less. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization temperature is 40 ° C or higher, generally 50 to
Polymerization is carried out by setting the temperature at 90 ° C. Further, the temperature may be raised in the latter half of the polymerization reaction.

Next, the pH of the suspension system is adjusted to alkali, and the polymerizable monomer for coating the polymer particles is carefully added dropwise while vigorously stirring the suspension system. Further, a water-soluble polymerization initiator is added to this to emulsify the polymerizable monomer, and the polymer particles are adsorbed and coated.

After that, the temperature is raised to 50 to 90 ° C. and heated to polymerize the coating layer on the surface of the polymer particles for 2 to 10 hours. In addition, the temperature may be raised in the latter half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers, by-products, etc. that cause odor during toner fixing, etc. in the latter half of the reaction or after the reaction is completed. Part of the aqueous medium may be distilled off.

After completion of the reaction, the produced toner particles are washed,
Collect by filtration and dry. In the suspension polymerization method,
Usually, 300 to 300 parts by weight of water based on 100 parts by weight of the monomer system.
It is preferred to use 0 parts by weight as the dispersion medium.

In measuring the particle size distribution in the present invention, a Coulter counter TA-II type (manufactured by Coulter) is used as a measuring device, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting number average distribution and volume average distribution and CX-.
1 A personal computer (Canon) was used. Further, as the electrolytic solution, a 1% NaCl aqueous solution was prepared using primary sodium chloride and used.

The measuring method is as follows:
To 150 ml, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the Coulter Counter TA-II type is used to measure the particle size distribution of particles of 2 to 40 μm using an aperture having an aperture diameter of 100 μm. The volume average distribution and the number average distribution were obtained by measurement, and the volume average diameter D ₄ was obtained from this.

[0085]

The present invention will be described below with reference to examples.
They do not limit the invention in any way. The production examples of the toners used in the examples of the present invention and the comparative examples are listed below.

(Production Example 1) 710 g of deionized water was added with 0.
It was charged 1M-Na ₃ PO ₄ aqueous solution 450 g, followed by heating to 60 ° C., using a TK homomixer (manufactured by Tokushu Kika) and stirred at 12,000 rpm.

68 g of 1.0 M CaCl ₂ aqueous solution
Was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

On the other hand, styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Copper phthalocyanine pigment 14 parts by weight Styrene-methacrylic acid-methyl methacrylate 9 parts by weight (monomer weight ratio = 85: 5: 10) Paraffin wax (mp 60) ℃) 60 parts by weight

The above formulation was heated to 60 ° C. and 12,000 rpm using a TK type homomixer (manufactured by Tokushu Kika Co., Ltd.)
Was uniformly dissolved and dispersed. Polymerization initiator 2,2'-
A polymerizable monomer composition was prepared by dissolving 10 parts by weight of azobis (2,4-dimethylvaleronitrile).

The above polymerizable monomer composition was added to the aqueous medium, and the mixture was stirred at 60 ° C. under N ₂ atmosphere with a TK type homomixer at 10,000 rpm for 20 minutes to granulate. Then, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C. and the reaction was carried out for 10 hours to obtain polymer particles. The volume average diameter D ₄ of the polymer particles was 8.29 μm.

After the completion of the polymerization reaction, the suspension system was cooled, and 3.6 parts by weight of Na ₂ CO ₃ was added and dissolved therein.

Next, as a synthetic resin monomer, 90 parts by weight of styrene monomer and 10 parts by weight of n-butyl acrylate were used for 0.05 by using a metering pump (manufactured by Nippon Feeder).
1.1 ml was dropped at a dropping rate of ml / min to adsorb and coat the surface of the polymer particles.

Further, 0.67 parts by weight of an azo polymerization initiator VA-558 (manufactured by Wako Pure Chemical Industries, Ltd.) represented by the following formula was gradually added, stirred and dissolved. After completion of the dropping, the temperature was raised to 80 ° C. with stirring, and the above synthetic resin monomer was reacted for 6 hours.

[0094]

Embedded image

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 8.43 μm.

To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of the hydrophobic titanium oxide fine powder was externally added to obtain a toner A having the titanium oxide fine powder on the surface of the toner particles.

To 6 parts by weight of this externally added toner, 94 parts by weight of a ferrite carrier coated with an acrylic resin was mixed to prepare a two-component developer.

Production Example 2 The composition of the polymerizable monomer composition of Production Example 1 was as follows: styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Copper phthalocyanine pigment 14 parts by weight Saturated polyester 10 parts by weight (terephthalic acid- Propylene oxide-modified bisphenol A; acid value 15, peak molecular weight 6000) Compound (1) (mp 59.4 ° C.) 60 parts by weight except that the weight average diameter D ₄ is the same as in Production Example 1.
To give polymer particles having a particle size of 8.07 μm.

After the completion of the polymerization reaction, the suspension system was cooled, and 3.6 parts by weight of Na ₂ CO ₃ was added and dissolved therein.

Next, as a synthetic resin monomer, 90 parts by weight of styrene monomer and 10 parts by weight of n-butyl acrylate were used for 0.05 with a metering pump (manufactured by Nippon Feeder).
2.8 ml was dropped at a dropping rate of ml / min to adsorb and coat the surface of the polymer particles.

Furthermore, in addition to this, an azo type polymerization initiator VA-55
1.34 parts by weight of 8 (manufactured by Wako Pure Chemical Industries, Ltd.) was gradually added, stirred and dissolved. After completion of the dropping, the temperature was raised to 80 ° C. with stirring, and the above synthetic resin monomer was reacted for 6 hours.

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 8.79 μm.

1.2 parts by weight of hydrophobic titanium oxide fine powder was externally added to 100 parts by weight of the obtained toner particles to obtain a toner B having the titanium oxide fine powder on the surface of the toner particles.

To 6 parts by weight of this externally added toner, 94 parts by weight of a ferrite carrier coated with an acrylic resin was mixed to prepare a two-component developer.

(Production Example 3) The composition of the polymerizable monomer composition of Production Example 1 was as follows: styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Copper phthalocyanine pigment 14 parts by weight Saturated polyester 10 parts by weight (terephthalic acid- Propylene oxide-modified bisphenol A; acid value 15, peak molecular weight 6000) Compound (2) (mp 76.5 ° C.) 60 parts by weight except that 60 parts by weight is used, and the volume average diameter D ₄ is the same as in Production Example 1.
To give 6.10 μm of polymer particles.

After the completion of the polymerization reaction, the suspension system was cooled, and 3.6 parts by weight of Na ₂ CO ₃ was added and dissolved therein.

Next, as a synthetic resin monomer, 90 parts by weight of styrene monomer and 10 parts by weight of n-butyl acrylate were used in 0.05 by using a metering pump (manufactured by Nippon Feeder).
1.1 ml was dropped at a dropping rate of ml / min to adsorb and coat the surface of the polymer particles.

Further to this, an azo polymerization initiator VA-55 was added.
0.67 parts by weight of 8 (manufactured by Wako Pure Chemical Industries, Ltd.) was gradually added, stirred and dissolved. After completion of the dropping, the temperature was raised to 80 ° C. with stirring, and the above synthetic resin monomer was reacted for 6 hours.

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 6.23 μm.

To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of the hydrophobic titanium oxide fine powder was externally added to obtain a toner C having the titanium oxide fine powder on the surface of the toner particles.

To 6 parts by weight of this externally added toner, 94 parts by weight of a ferrite carrier coated with an acrylic resin was mixed to obtain a two-component developer.

(Production Example 4) The composition of the polymerizable monomer composition of Production Example 1 was as follows: styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Copper phthalocyanine pigment 14 parts by weight Saturated polyester 10 parts by weight (terephthalic acid- Propylene oxide-modified bisphenol A; acid value 15, peak molecular weight 6000) Compound (3) (mp 73.8 ° C.) 60 parts by weight except for substituting for the same amount of volume average diameter D ₄ as in Production Example 1.
To give polymer particles having a particle size of 5.38 μm.

After the completion of the polymerization reaction, the suspension system was cooled, and 3.6 parts by weight of Na ₂ CO ₃ was added and dissolved therein.

Next, as a synthetic resin monomer, 90 parts by weight of styrene monomer and 10 parts by weight of n-butyl acrylate were used to obtain 0.05 parts by weight using a metering pump (manufactured by Nippon Feeder).
2.2 ml was dropped at a dropping rate of ml / min to adsorb and coat the surface of the polymer particles.

Further, 1.34 parts by weight of an azo type polymerization initiator VA-044 (manufactured by Wako Pure Chemical Industries, Ltd.) represented by the following formula was gradually added, stirred and dissolved. After completion of the dropping, the temperature was raised to 80 ° C. with stirring, and the above synthetic resin monomer was reacted for 6 hours.

[0116]

Embedded image

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 5.43 μm.

To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of the hydrophobic titanium oxide fine powder was externally added to obtain a toner D having the titanium oxide fine powder on the surface of the toner particles.

To 6 parts by weight of this externally added toner, 94 parts by weight of a ferrite carrier coated with an acrylic resin was mixed to prepare a two-component developer.

(Production Example 5) The composition of the polymerizable monomer composition of Production Example 1 was as follows: styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Hydrophobized magnetic material 140 parts by weight Di-t-butyl salicylate metal Compound 2 parts by weight Styrene-methacrylic acid copolymer 10 parts by weight Compound (3) (mp 73.8 ° C.) 20 parts by weight, except for replacing by 20 parts by weight, and in the same manner as in Production Example 1, volume average diameter D ₄
To obtain polymer particles having a particle diameter of 8.29 μm.

After the completion of the polymerization reaction, the suspension system was cooled, and 3.6 parts by weight of Na ₂ CO ₃ was added and dissolved therein.

Then, as a synthetic resin monomer, 80 parts by weight of a styrene monomer and 20 parts by weight of n-butyl acrylate were used for 0.05 by using a metering pump (manufactured by Nippon Feeder).
1.1 ml was dropped at a dropping rate of ml / min to adsorb and coat the surface of the polymer particles.

Furthermore, in addition to this, an azo polymerization initiator VA-55
0.67 parts by weight of 8 (manufactured by Wako Pure Chemical Industries, Ltd.) was gradually added, stirred and dissolved. After completion of the dropping, the temperature was raised to 80 ° C. with stirring, and the above synthetic resin monomer was reacted for 6 hours.

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 8.43 μm.

To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of hydrophobic titanium oxide fine powder was externally added to obtain a toner E having the titanium oxide fine powder on the surface of the toner particles.

To 6 parts by weight of this externally added toner, 94 parts by weight of a ferrite carrier coated with an acrylic resin was mixed to obtain a two-component developer.

(Production Example 6) The composition of the polymerizable monomer composition of Production Example 1 was as follows: styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Hydrophobized magnetic material 140 parts by weight Di-t-butyl salicylate metal Compound 1 part by weight Styrene-methacrylic acid copolymer 10 parts by weight Compound (1) (mp 59.4 ° C.) 20 parts by weight except that the amount of the compound is changed to 20 parts by weight, and the volume average diameter D _{4 is the same.}
To give 6.92 μm of polymer particles.

After the completion of the polymerization reaction, the suspension system was cooled, and 3.6 parts by weight of Na ₂ CO ₃ was added and dissolved therein.

Next, as a synthetic resin monomer, 90 parts by weight of a styrene monomer and 10 parts by weight of n-butyl acrylate were used for 0.05 by using a metering pump (manufactured by Nippon Feeder).
2.2 ml was dropped at a dropping rate of ml / min to adsorb and coat the surface of the polymer particles.

Furthermore, in addition to this, an azo polymerization initiator VA-04
1.34 parts by weight of 4 (manufactured by Wako Pure Chemical Industries, Ltd.) was gradually added, stirred and dissolved. After completion of the dropping, the temperature was raised to 90 ° C. with stirring, and the above synthetic resin monomer was reacted for 6 hours.

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 7.27 μm.

To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of the hydrophobic titanium oxide fine powder was externally added to obtain a toner F having the titanium oxide fine powder on the surface of the toner particles.

Six parts by weight of this externally added toner was mixed with 94 parts by weight of a ferrite carrier coated with an acrylic resin to obtain a two-component developer.

(Production Example 7) The composition of the polymerizable monomer composition of Production Example 1 was as follows: styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Copper phthalocyanine pigment 14 parts by weight Saturated polyester 10 parts by weight (terephthalic acid- Propylene oxide-modified bisphenol A; acid value 15, peak molecular weight 6000) Compound (1) (mp 59.4 ° C.) 60 parts by weight except that the weight average particle diameter D ₄ is the same as in Production Example 1.
To give 6.10 μm of polymer particles.

After the completion of the polymerization reaction, the suspension system was cooled, and 3.6 parts by weight of Na ₂ CO ₃ was added and dissolved therein.

Next, as a synthetic resin monomer, 98 parts by weight of styrene monomer and 2 parts by weight of acrylic acid monomer were added to 0.05 parts by using a metering pump (manufactured by Nippon Feeder).
2.2 ml was dropped at a dropping rate of ml / min to adsorb and coat the surface of the polymer particles.

Further, 1.12 parts by weight of potassium persulfate was gradually added to this, and stirred and dissolved. After completion of the dropping, the temperature was raised to 70 ° C. with stirring, and the above synthetic resin monomer was reacted for 6 hours.

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 6.49 μm.

To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of the hydrophobic titanium oxide fine powder was externally added to obtain a toner G having the titanium oxide fine powder on the surface of the toner particles.

Six parts by weight of this externally added toner was mixed with 94 parts by weight of a ferrite carrier coated with an acrylic resin to obtain a two-component developer.

Production Example 8 The composition of the polymerizable monomer composition of Production Example 1 was as follows: styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Hydrophobized magnetic material 140 parts by weight Di-t-butyl salicylate metal compound 1 part by weight of styrene - methacrylic acid copolymer 10 parts by weight compound (3) (mp 73.8 ℃) addition replaced with 20 parts by weight, in the same manner as in preparation example 1, the volume average diameter D ₄
To obtain polymer particles having a particle size of 8.02 μm.

After the completion of the polymerization reaction, the suspension system was cooled, and 3.6 parts by weight of Na ₂ CO ₃ was added and dissolved therein.

Next, as a synthetic resin monomer, 98 parts by weight of a styrene monomer and 2 parts by weight of an acrylic acid monomer were mixed with 0.05 by using a metering pump (manufactured by Nippon Feeder).
2.2 ml was dropped at a dropping rate of ml / min to adsorb and coat the surface of the polymer particles.

Furthermore, in addition to this, the azo polymerization initiator VA-04
1.12 parts by weight of 4 (manufactured by Wako Pure Chemical Industries, Ltd.) was gradually added, stirred and dissolved. After completion of the dropping, the temperature was raised to 90 ° C. with stirring, and the above synthetic resin monomer was reacted for 6 hours.

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 8.22 μm.

To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of the hydrophobic titanium oxide fine powder was externally added to obtain a toner H having the titanium oxide fine powder on the surface of the toner particles.

To 6 parts by weight of this externally added toner, 94 parts by weight of a ferrite carrier coated with an acrylic resin was mixed to obtain a two-component developer.

(Production Example 9) The composition of the polymerizable monomer composition of Production Example 1 was as follows: styrene monomer 165 parts by weight n-butyl acrylate 35 parts by weight Copper phthalocyanine pigment 14 parts by weight Styrene-methacrylic acid-methyl methacrylate 10 Parts by weight (monomer weight ratio = 85: 5: 10) Polymer particles were obtained in the same manner as in Production Example 1 except that 60 parts by weight of paraffin wax (mp 60 ° C.) was used.

Next, this was cooled to room temperature, hydrochloric acid was added to dissolve calcium phosphate, and then filtration, washing with water and drying were carried out to obtain toner particles. The volume average diameter D ₄ of the toner particles was 6.7 μm.

To 100 parts by weight of the obtained toner particles, 1.2 parts by weight of the hydrophobic titanium oxide fine powder was externally added to obtain a toner I having the titanium oxide fine powder on the surface of the toner particles.

To 6 parts by weight of this externally added toner, 94 parts by weight of a ferrite carrier coated with an acrylic resin was mixed to obtain a two-component developer.

Examples using the above toner will be shown below.

[0153] Example 1 using the developer prepared using toner A produced in accordance with Production Example 1, a commercially available full-color copying machine CLC5
An image was copied in a 00 remodeling machine (manufactured by Canon Inc.) under the environment of 23 ° C. and 60% RH, and the image durability and charge stability were evaluated, and the results are shown in Table 1.

Image density decrease even at the durability of 100,000 sheets,
No image defects such as toner scattering and fog were observed.
A high-definition image faithful to the original document was obtained.

Further, in order to evaluate the chargeability of the toner,
When the charge amount was measured by the blow-off method, the initial value was -27 mC / kg, and the value after endurance was -26 mC / kg, showing a uniform and stable value.

Example 2 The toner A prepared according to the above Production Example 1 was used, and the developer prepared was used.
Images were copied in an environment of 80 ° C. and 80% RH, and their image durability and charge stability were evaluated. The results are shown in Table 1.

Image density decrease even at the durability of 100,000 sheets,
No image defects such as toner scattering and fog were observed.
A high-definition image faithful to the original document was obtained.

In order to evaluate the chargeability of the toner,
When the charge amount was measured by the blow-off method, it showed a uniform and stable value of -23 mC / kg at the initial stage and -22 mC / kg after the endurance test.

Example 3 The toner B prepared according to the above Production Example 2 was used, and the prepared developer was used to prepare a toner with a modified CLC500 machine.
Images were copied in an environment of 80 ° C. and 80% RH, and their image durability and charge stability were evaluated. The results are shown in Table 1.

The image density is lowered even after the durability of 100,000 sheets.
No image defects such as toner scattering and fog were observed.
A high-definition image faithful to the original document was obtained.

In order to evaluate the chargeability of the toner,
When the charge amount was measured by the blow-off method, it showed a uniform and stable value of -23 mC / kg at the initial stage and -23 mC / kg after the endurance test.

Example 4 The toner C prepared according to the above Production Example 3 was used, and the developer prepared was used.
Images were copied in an environment of 80 ° C. and 80% RH, and their image durability and charge stability were evaluated. The results are shown in Table 1.

Image density decrease even at the durability of 100,000 sheets,
No image defects such as toner scattering and fog were observed.
A high-definition image faithful to the original document was obtained.

In order to evaluate the chargeability of the toner,
When the charge amount was measured by the blow-off method, it showed a uniform and stable value of -25 mC / kg at the initial stage and -23 mC / kg after the endurance test.

Example 5 The toner D prepared according to the above Production Example 4 was used, and the developer prepared was used to prepare a toner with a modified CLC500 machine.
Images were copied in an environment of 80 ° C. and 80% RH, and their image durability and charge stability were evaluated. The results are shown in Table 1.

[0166] The image density is lowered even after the durability of 100,000 sheets.
No image defects such as toner scattering and fog were observed.
A high-definition image faithful to the original document was obtained.

In order to evaluate the chargeability of the toner,
When the charge amount was measured by the blow-off method, it showed a uniform and stable value of -22 mC / kg at the initial stage and -23 mC / kg after the endurance test.

Example 6 The toner D prepared according to the above Production Example 4 was used, and the developer prepared was used to prepare a toner in a CLC500 remodeling machine.
The image was copied under the environment of 60 ° C. and 60% RH, and the image durability and charge stability were evaluated, and the results are shown in Table 1.

The image density is lowered even after the durability of 100,000 sheets.
No image defects such as toner scattering and fog were observed.
A high-definition image faithful to the original document was obtained.

Further, in order to evaluate the chargeability of the toner,
When the charge amount was measured by a blow-off method, it showed a uniform and stable value of −26 mC / kg at the initial stage and −26 mC / kg after the endurance test.

Example 7 Using the toner E prepared according to the above Production Example 5 and using the prepared developer, a commercially available copying machine NP6000 (manufactured by Canon) remodeling machine was used at 23 ° C. and 60% RH environment. An image was copied and evaluated for image durability and charge stability, and the results are shown in Table 1.

The image density is lowered even after the durability of 100,000 sheets.
No image defects such as toner scattering and fog were observed.
A high-definition image faithful to the original document was obtained.

In order to evaluate the chargeability of the toner,
When the charge amount was measured by the blow-off method, it showed a uniform and stable value of -25 mC / kg at the initial stage and -27 mC / kg after the endurance test.

Example 8 The toner E produced according to the above Production Example 5 was used, and the developer prepared was used.
Images were copied in an environment of 80 ° C. and 80% RH, and their image durability and charge stability were evaluated. The results are shown in Table 1.

The image density is lowered even after the durability of 100,000 sheets.
No image defects such as toner scattering and fog were observed.
A high-definition image faithful to the original document was obtained.

In order to evaluate the chargeability of the toner,
When the charge amount was measured by the blow-off method, it showed a uniform and stable value of -24 mC / kg at the initial stage and -23 mC / kg after the endurance test.

Comparative Example 1 The same evaluation as in Example 1 was carried out at 23 ° C. and 60% RH using the developer prepared from Toner F produced according to the above Production Example 6. The results are shown in Table 1.

Regarding the image quality, good high-definition images were obtained up to the endurance number of 30,000 sheets, but at the end of the endurance number of 50,000 sheets, image defects such as toner scattering and image density decrease occurred. Was recognized, and the copied image was unclear.
Further, the charge amount was significantly increased from −24 mC / kg at the initial stage to −37 mC / kg at the durability of 30,000 sheets.

Comparative Example 2 The same evaluation as in Example 1 was carried out at 28 ° C. and 80% RH using the developer prepared from Toner G produced according to Production Example 7 above. The results are shown in Table 1.

Good fixability was exhibited in all ranges. Two
Good image quality was obtained at the endurance of 10,000 sheets, but unclear copy images could not be obtained at the endurance of 30,000 sheets due to toner scattering.

Further, the charge amount was −26 mC / kg at the initial stage, but was significantly decreased to −16 mC / kg at the endurance of 30,000 sheets.

Comparative Example 3 The same evaluation as in Example 1 was carried out at 23 ° C. and 60% RH using the developer prepared from Toner H produced according to Production Example 8 above. The results are shown in Table 1.

The initial charge amount was −27 mC / kg, but it decreased with the endurance, and at the endurance of 30,000 sheets, −19 mC / kg.
And there was some fog and scattering.

Comparative Example 4 The same evaluation as in Example 1 was carried out at 28 ° C. and 80% RH using the developer prepared from Toner I prepared according to the above Production Example 9. The results are shown in Table 1.

A little toner scattering and fogging occurred during the durability test after 30,000 sheets. The charge amount was -23 mC / kg at the initial stage and -18 mC / kg after the durability test.

[0186]

[Table 1]

[0187]

According to the present invention, a uniform coating layer is formed with a minimum amount of coating, and in addition to improving productivity and image quality durability, charging property, uniform charging and stability thereof are simultaneously achieved. Can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic view of a toner layer in which a substance having a low softening point is encapsulated by an outer shell resin.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takehiko Chiba 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. A toner for developing an electrostatic charge image, comprising a coating layer on polymer particles, wherein the coating layer is represented by the following formula: A toner for developing an electrostatic charge image, which is a coating layer formed by using a polymerization initiator represented by: 2. The low softening point substance is encapsulated in the coating layer and directly polymerized by observing the cross-sectional layer of the polymer particles or the toner using a transmission electron microscope (TEM). The toner for developing an electrostatic image as described in 1. 3. The toner for developing an electrostatic charge image according to claim 2, wherein the low softening point substance is an ester wax having at least one long chain ester portion having 10 or more carbon atoms. 4. A step of forming a coating layer on polymer particles, wherein the following formula: A method for producing a toner for developing an electrostatic charge image, which comprises forming a coating layer using a polymerization initiator represented by: