JPH01113761A - Toner for developing electrostatic image - Google Patents

Abstract

PURPOSE:To improve developing effect and cleaning effect of a toner for developing electrostatic images, and to form picture images contg. no black spots many times repeatedly by incorporating fine inorganic powder and smaller org. particles than binder resin particles into binder resin particles consisting of a specified crosslinked polyester. CONSTITUTION:The title toner is prepd. by mixing binder resin particles (A) with inorganic fine particles (B) and the org. particles (C) having smaller particle size than (A). A crosslinked polyester prepd. by the polymn. of a monomer compsn. consisting of a polybasic acid having >=3 functional groups and/or a polyhydric alcohol having >=3 functional groups, and having a long-chain aliphatic hydrocarbon unit in the principal chain and or side chain is used for the material of the particle (A). Silica or surface-treated silica is used pref. for the material of the particle (B). It is particularly pref. to use >=2 kinds of such silica. Further, it is pref. that a vinyl polymer, particularly acrylic polymer, having 0.01-5mum mean particle size is used for the material of the particle (C).

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to developing an electrostatic latent image formed on the surface of a latent image carrier in, for example, electrophotography, electrostatic recording, electrostatic printing, etc. This invention relates to toner for developing electrostatic images.

[Technology background]

In general, in electrophotography, a latent image carrier having a photosensitive layer made of a photoconductive material is given an electrostatic charge, and then the surface of the latent image carrier is exposed to light. A corresponding electrostatic latent image is formed, and this electrostatic latent image is developed by the developer conveyed to the development area by the developer conveyance carrier to form a toner image. This toner image is transferred to a transfer material such as paper and then fixed by heating, pressure, etc. to form a copy image. On the other hand, after the transfer step, the latent image carrier is neutralized, the remaining developer after transfer is cleaned, and then the latent image carrier is used for forming the next copy image.

Therefore, in order to achieve good development, it is required that the developer transport carrier stably transport an appropriate amount of toner to the development area, and for this purpose, the toner must have high fluidity. be done. From this point of view, toners have conventionally been prepared by adding and mixing fine silica powder to binder resin particles.

[Problem that the invention seeks to solve]

However, in toners mixed with fine silica powder, the fine silica powder is quite hard, so when cleaning the residual toner with a cleaning blade placed in contact with the latent image carrier with a large pressure contact force, the fine silica powder is caught between the cleaning blade and the latent image carrier, and the surface of the latent image carrier is rubbed, resulting in a problem in that the surface of the latent image carrier is likely to be damaged. When the surface of the latent image carrier is damaged in this way, fine silica powder, etc. is embedded in the wound and cannot be cleaned. There is a problem in that this adheres and is fixed, resulting in black spot-like stains (black spots) on the image.

In addition, with toner mixed with fine silica powder, as images are repeatedly formed, a filming phenomenon occurs in which toner substances adhere to the surface of the developer transport carrier and form a film. There is a problem in that the toner transportability deteriorates and the amount of toner transported to the development area gradually decreases, resulting in a decrease in image density.

In addition, toner containing fine silica powder has a large electrostatic adhesion force to the latent image carrier.
There is a problem in that the transfer rate of a toner image formed by development onto a transfer material is generally low, resulting in a decrease in image density.

Particularly, when the toner is used as a one-component developer, since the toner contains magnetic powder, the weight of the toner increases, resulting in a further reduction in the transfer rate.

In addition, in order to achieve stable development over a long period of time, it is required that the toner does not aggregate and has good storage stability (blocking resistance) as a powder.

The present invention has been made based on the above-mentioned circumstances, and is capable of improving developing performance and cleaning performance, and stably forming images with high image density over many times without the occurrence of black spots. The object of the present invention is to provide a toner for electrostatic image development, which has excellent storage stability as a powder and can achieve stable development over a long period of time.

[Means for solving problems]

The electrostatic image developing toner of the present invention comprises binder resin particles made of crosslinked polyester obtained by polymerizing a monomer composition containing a trifunctional or higher functional polybasic acid and/or a trifunctional or higher functional polyhydric alcohol. , inorganic fine particles, and organic fine particles having a smaller diameter than the binder resin particles.

[Function and effect of the invention]

According to the present invention, since organic fine particles are contained together with inorganic fine particles, good developability is exhibited due to the effect of improving the fluidity of the toner by the inorganic fine particles, and the so-called lubricating effect of the organic fine particles makes it possible to improve the toner. Since both the physical adhesion force and the electrostatic adhesion force to the latent image carrier are weakened, residual toner can be easily cleaned.

Therefore, it is possible to achieve good cleaning with a small pressure contact force of the cleaning blade against the latent image carrier, and as a result, damage to the surface of the latent image carrier due to inorganic fine particles can be prevented, and there is no black spot. Images can be stably formed many times.

The so-called lubricating action of the organic fine particles suppresses the occurrence of the filming phenomenon of the developer transport carrier due to toner substances, and the organic fine particles also provide appropriate polishing performance, so that the toner substances temporarily adhere to the developer transport carrier. Even if it does, it can be easily removed, and since the binder resin particles are made of a specific crosslinked polyester and are relatively hard, there is less chance of the binder resin adhering to the developer transport carrier. As a result, even when an image is formed many times, the ability of the developer transport carrier to transport the toner to the development area is stable, and a decrease in image density does not occur.

The so-called lubricating action of organic fine particles weakens both the physical adhesion force and the electrostatic adhesion force of the toner to the latent image carrier, so that the toner image formed by development is transferred to the transfer material. As a result, an image with high image density can be formed. Furthermore, as a result of the high transfer rate, the amount of residual toner remaining on the latent image carrier without being transferred is reduced, and from this point of view as well, cleaning of the residual toner becomes easier.

[Specific structure of the invention]

In the present invention, a toner for electrostatic image development is constructed using binder resin particles made of a specific crosslinked polyester, inorganic fine particles, and organic fine particles having a smaller diameter than the binder resin particles as essential components. The electrostatic image developing toner of the present invention can be applied to any type of one-component developer that does not contain a carrier or a two-component developer that contains a carrier.

The organic fine particles have a smaller diameter than the binder resin particles, for example, the average diameter of the secondary particles (particles separated into individual unit particles) is 0. It is preferably O1 to 5ua, especially 0
．． 1 to 3JI11 are preferred. In particular, it is preferable that the layer be 3 μm or less and larger than the average diameter of the primary particles of the inorganic fine particles. When the average diameter of the primary particles of the organic fine particles is too large, the toner transfer rate decreases and the image density decreases. Also,
When the average diameter of the primary particles of the organic fine particles is smaller than the average diameter of the primary particles of the inorganic fine particles, cleaning failure occurs.

The proportion of organic fine particles is 0.0% of the total toner. O is preferably 1 to 3.0% by weight, particularly preferably 0.1 to 2% by weight. When the proportion of organic fine particles is too small, the toner transfer rate tends to decrease, the toner transportability tends to decrease, and furthermore, cleaning defects tend to occur. On the other hand, if it is too large, the triboelectric charging properties of the toner are likely to be inhibited.

The organic substance for forming the organic fine particles is not particularly limited, but vinyl polymers are preferred because they are relatively hard and provide appropriate polishing performance.

Such vinyl polymers can be produced by various polymerization methods such as emulsion polymerization and suspension polymerization, but the emulsion polymerization method is preferred because small-diameter, spherical organic fine particles can be efficiently obtained. In particular, in systems where the monomer itself for obtaining the vinyl polymer has an emulsifying effect, it is preferable to obtain the vinyl polymer by emulsion polymerization without using an emulsifier. On the other hand, when an emulsifier is used, the emulsifier may inhibit the triboelectric charging properties of the toner or may increase the environmental dependence of the triboelectrification properties on temperature and humidity.

Examples of the vinyl polymer include acrylic polymers, styrene polymers, vinyl group-containing fluororesins, and among them, acrylic polymers are preferred.

The acrylic polymer is a homopolymer or copolymer obtained by polymerizing monomers selected from acrylic acid, ester of acrylic acid, methacrylic acid, and ester of methacrylic acid. Acrylic monomers used to obtain such acrylic polymers include acrylic acid,
acrylic acid metinobe ethyl acrylate, acrylic acid n-
Butyl, isobutyl acrylate, propyl acrylate,
n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methacrylic acid, methyl methacrylate, methacrylic acid Ethyl, propinope methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, methacrylic acid 2
-Ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

Among the acrylic polymers, polymethyl methacrylate is particularly preferred. With polymethyl methacrylate, uniform and small-diameter organic fine particles can be easily obtained,
In addition, it is possible to obtain appropriate polishing performance and to suitably weaken both the physical adhesion force and the electrostatic adhesion force of the toner to the latent image carrier or the developer transport carrier. Demonstrated. Furthermore, since there is no risk of inhibiting the triboelectric charging properties of the toner, stable developing performance can be obtained.

The acrylic polymer may be copolymerized with other monomers, if necessary.

In this case, it is preferable to use the acrylic monomer in a proportion of 50% by weight or more in the monomer composition. Such other monomers include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-7nylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenyl Styrenic monomers such as styrene, p-chlorostyrene, 3,4-dichlorostyrene,
Acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; Vinyl esters such as vinyl acetate and vinyl butyrate and vinyl benzoate; Vinyl ethers such as vinyl methyl ether debenzoinyl ethyl ether; Vinyl ketones such as vinyl methyl ketone: Dienes such as butadiene and isoprene; unsaturated carboxylic acids such as maleic acid and fumaric acid; and others.

It is necessary that the average diameter of the secondary particles (particles separated into individual unit particles) of the inorganic fine particles is smaller than the average diameter of the primary particles of the organic fine particles.

When the average diameter of the primary particles of the inorganic fine particles is too large, damage occurs to the surface of the latent image carrier. Practically speaking, the average diameter of the primary particles of the inorganic fine particles is preferably 2 zm or less, particularly 1 zm or less.
It is preferable that it is less than μ-dust.

The proportion of the inorganic fine particles is preferably 0.05 to 2.0% by weight, particularly preferably 0.1 to 1.0% by weight, based on the total toner. When the proportion of inorganic fine particles is too small, the fluidity of the toner decreases, while when the proportion is too large, the surface of the latent image carrier is likely to be damaged.

The constituent materials of the inorganic fine particles are not particularly limited, but include, for example, oxides such as silica, titanium oxide, aluminum oxide, zirconium oxide, barium titanate, lead titanate, and barium carbonate; nitrides such as silicon nitride and boron nitride; and carbide. Carbides such as silicon, aluminum carbide, titanium carbide;
Others can be mentioned. These inorganic fine particles may be surface-treated.

Particularly preferred are silica fine particles or surface-treated silica fine particles. As the surface treatment agent, for example, a silane coupling agent, a titanium coupling agent, etc. can be used. The surface-treated silica fine particles are highly stable against environmental changes such as temperature and humidity, so that the environmental dependence of the triboelectric charging property of the toner can be suppressed to a small level.

Two or more types of inorganic fine particles may be used in combination. In this case, it is preferable to always use silica fine particles or surface-treated silica fine particles.

The above organic fine particles and inorganic fine particles are preferably used by being added to and mixed with the binder resin particles from the outside. Specifically, by mixing binder resin particles, organic fine particles, and inorganic fine particles using a mixing device such as a V-type blender, organic fine particles and inorganic fine particles are present on the surface of the binder resin particles. It is preferable to let

The resin constituting the binder resin particles is a crosslinked polyester obtained by polymerizing a monomer composition containing a trifunctional or higher functional polybasic acid and/or a trifunctional or higher functional polyhydric alcohol.

Particularly preferred is a crosslinked polyester having long chain aliphatic hydrocarbon units in its main chain and/or side chain. By using a crosslinked polyester having such a long-chain aliphatic hydrocarbon unit, the melt viscoelasticity during toner fixing is within a suitable range, and excellent offset resistance can be obtained. Due to the characteristics of the unit, the toner can be melted at a lower temperature, and its adhesion to transfer materials such as paper is improved, and particularly excellent low-temperature fixing properties are exhibited under low-temperature, low-humidity environmental conditions.

The above-mentioned specific crosslinked polyester is basically a monomer composition containing a bifunctional basic acid and a bifunctional alcohol, and a trifunctional or higher functional polybasic acid and/or a trifunctional or higher functional polyhydric alcohol. It is obtained by polymerization.

The binder resin particles may contain other resins in addition to the specific crosslinked polyester, but in this case, the specific crosslinked polyester must be contained in a proportion of at least 50% by weight or more. is preferred.

Examples of monomers used in the synthesis of the specific crosslinked polyester include those shown in (a) to (c) below, and other monomers may be used as necessary.

(a) A difunctional basic acid monomer and a difunctional alcohol monomer as components constituting the basic skeleton, that is, the main chain of polyester.

(b) A trifunctional or more functional polybasic acid and/or a trifunctional or more functional polyhydric alcohol monomer that participates in crosslinking, that is, branching or reticulation of polyester.

(c) A bifunctional or higher functional basic acid monomer having a long-chain aliphatic hydrocarbon unit for introducing a long-chain aliphatic hydrocarbon unit into the main chain and/or side chain of the polyester.
Or a bifunctional or more functional alcohol monomer having the long-chain aliphatic hydrocarbon unit.

Incidentally, the long chain in the long chain aliphatic hydrocarbon unit refers to a straight chain having 3 or more carbon atoms, preferably 3 to 30 carbon atoms. Especially in terms of low temperature fixability, it is 5-2.
2 is preferred.

Examples of the bifunctional basic acid monomer in (a) include terephthalic acid, succinic acid, fumaric acid, maleic acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, and cyclohexanedicarboxylic acid. , adipic acid, sebacic acid, malonic acid, anhydrides of these acids, dimers of lower alkyl esters and liluic acid, and other bifunctional organic acid monomers. Among these, terephthalic acid, succinic acid, and fumaric acid are particularly preferred. The proportion of the difunctional basic acid monomer to be used is preferably 10 to 90 mol% based on the total acid component, particularly the difunctional basic acid monomer.
0 to 60 mol% is preferred.

Examples of the bifunctional alcohol monomer in (a) above include ethylene glycol, diethylene glycol,
Diols such as triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butynediol; 1,4-bis(hydroxymethyl)cyclohexane , bisphenol A1, hydrogenated bisphenol A1, etherified bisphenol, and the like. Among these, etherified bisphenols are particularly preferred, and specific examples include polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)furopane, polyoxyethylene (2)-2,2-his (4-hydroxyphenyl)furopane, polyoxypropylene (6)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (1,3)-2,
Examples include 2-bis(4-hydroxyphenyl)propane. The proportion of the bifunctional alcohol monomer used is preferably 10 to 90 mol% based on the total alcohol component.

Examples of the trifunctional or higher functional polybasic acid monomer in (b) include 1.2.4-benzenetricarboxylic acid, 1.
2.5-benzenetricarboxylic acid, 1.2.4-cyclohexanetricarboxylic acid, 2,5.7-naphthalenetricarboxylic acid, 1.2.4-naphthalenetricarboxylic acid,
1,2.4-butanetricarboxylic acid, 1゜2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxylpropane, tetra(methylenecarboxyl) meta:/, 1.2. Examples include 7.8-octane tetracarboxylic acid, Empol trimer acid, and anhydrides of these acids. The proportion of trifunctional or higher polybasic acid monomer used is 1 to 30% of the total acid component.
Mol% is preferred.

Examples of the trifunctional or higher functional polyhydric alcohol monomer in (b) include pentaerythritone hydroquinone, sorbitol, 1,2,3.6-hexanetetrol, 1,4-sorbitan, dipentaerythritol, Tripentaerythritol, sucrose, 1.2.4-butanetriol, 1.2.5-pentanetriol, glyceronope 2-methylpropanetriol, 2-methyl-
Examples include 1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3.5-trihydroxymethylbenzene. this house,
Particularly preferred are pentaerythritol and hydroquinone.

The proportion of the trifunctional or higher functional polyhydric alcohol monomer used is preferably 5 to 50 mol%, particularly preferably 10 to 40 mol%, based on the entire alcohol component.

2 having a long chain aliphatic hydrocarbon unit in the above (c)
Among functional or higher basic acid monomers, those having a long chain aliphatic hydrocarbon unit in the main chain of the basic acid monomer include, for example, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, Sebacic acid and the like can be mentioned.

2 having a long chain aliphatic hydrocarbon unit in the above (c)
Among functional or higher alcohol monomers, those having a long chain aliphatic hydrocarbon unit in the main chain of the alcohol monomer include, for example, propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc. can be mentioned. 2 having long chain aliphatic hydrocarbon units in the main chain
The functional or higher basic acid monomer or the bifunctional or higher functional alcohol monomer is added to the main chain of the crosslinked polyester in an amount of 1 to 60 mol%, preferably 5 to 50 mol% of the constituent units of the main chain. It is preferred to use proportions such that chain aliphatic hydrocarbon units are present.

2 having a long chain aliphatic hydrocarbon unit in the above (c)
Among functional or higher basic acid monomers, those having a long chain aliphatic hydrocarbon unit in the side chain of the basic acid monomer include 2
Examples include those in which the side chain of a functional or higher basic acid monomer is substituted with a long-chain aliphatic hydrocarbon group. This way 2
Examples of the basic acid monomers having higher functionality include the above (a) and (
Those exemplified as basic acid monomers in (b) can be used. Among these, particularly preferred are, for example, n-dodecenylsuccinic acid, iso-dodecenylsuccinic acid, n-dodecylsuccinic acid, iso-dodecylsuccinic acid,
Iso-octylsuccinic acid, n-octylsuccinic acid, n-
Butylsuccinic acid and the like can be mentioned. In addition, the above (
Among the bifunctional or more functional alcohol monomers having long-chain aliphatic hydrocarbon units in c), those having long-chain aliphatic hydrocarbon units in the side chains of the alcohol monomers include:
Examples include those in which the side chain of a bifunctional or more functional alcohol monomer is substituted with a long-chain aliphatic hydrocarbon group. As such alcohol monomers having two or more functionalities, those exemplified as alcohol monomers in (a) and (b) above can be used. In addition, the usage ratio of a difunctional or higher functional basic acid monomer having a long chain aliphatic hydrocarbon unit in its side chain and/or a difunctional or higher functional alcohol monomer having a long chain aliphatic hydrocarbon unit in its side chain is The total amount of both is preferably 1 to 50 mol% based on the entire monomer component, particularly 1 to 50 mol%.
0 to 30 mol% is preferred.

The above binder resin contains a magnetic substance, a colorant, an offset inhibitor, a charge control agent, etc., as necessary.

Magnetic substances include substances that are strongly magnetized in the direction of a magnetic field, such as metals or alloys that exhibit ferromagnetism such as iron, ferrite, and magnetite, such as iron, nickel, and cobalt, compounds containing these elements, and ferromagnetic elements. Alloys that do not contain manganese but become ferromagnetic through appropriate heat treatment, such as manganese-copper-aluminum, manganese-copper-tin, etc. Alloys called Heusler alloys that contain manganese and copper, chromium dioxide , and others. The average particle size of the magnetic material is 0.1
-IJIM is preferably contained uniformly dispersed in the form of fine powder. When the toner is used as a -component developer, the content of the magnetic material is preferably 20 to 80% by weight, particularly preferably 30 to 70% by weight, based on the total toner.

Examples of colorants include carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green offsalate,
Mention may be made of lamp black, rose bengal, mixtures thereof, and others.

Examples of anti-offset agents include low softening point polyolefins, high melting point paraffin waxes, silicone resins, fatty acid esters or partially saponified products thereof, fatty acid amide compounds, higher alcohols, and the like.

Examples of the charge control agent include metal complex dyes, nigrosine dyes, and ammonium salt compounds.

〔Example〕

Examples of the present invention will be specifically described below, but the present invention is not limited to these Examples.

Production of crosslinked polyester> (1) Crosslinked polyester A (for the present invention) polyoxypropylene (2,2) -2,2-bis(4-hydroxyphenyl)propa2221 299 g of taric acid, 82 g of pentaerythritol and of,
Place it in a round-bottom flask equipped with a thermometer, stainless steel stirrer, glass gas inlet tube, and flow-down condenser, set it on a mantle heater, and introduce nitrogen gas through the gas inlet tube to make the inside of the flask flush. Raise the temperature while maintaining an active atmosphere.

And 0. Add 0.5 g of dibutyltin oxide,
Crosslinked polyester A was produced by reacting at a temperature of 200° C. while monitoring the reaction at the softening point.

This crosslinked polyester A was prepared using the ring and ball method (JIS K 25
31-1960) was 135° C., and the chloroform-insoluble content was 17% by weight.

(2) Crosslinked polyester B (for the present invention) polyoxypropylene (2.2) -2. 700 g of 2-bis(4-hydroxyphenyl)propane! : , 150 g of fumaric acid and 55.4 g of n-dodecenylsuccinic anhydride.
and 0.1 g of hydroquinone were placed in a round-bottomed flask equipped with a thermometer, a stainless steel stirrer, a glass gas inlet tube, and a flow-down condenser. Introduce gas and raise the temperature while maintaining an inert atmosphere inside the flask.
The reaction was carried out at a temperature of 250°C under stirring. When water stopped flowing out due to the reaction, the acid value was measured to be 1.5.

Saral: 65=4 g of 1,2.4-benzenetricarboxylic acid anhydride was added and reacted for about 8 hours, and the reaction was terminated when the acid value reached 20 to obtain crosslinked polyester B. .

This crosslinked polyester B has a softening point of 12 according to the ring and ball method.
The temperature was 8°C.

(3) Crosslinked polyester C (for the present invention) polyoxypropylene (2.2) -2. 650g of 2-bis(4-hydroxyphenyl)propane, 120g of fumaric acid
and 55.4 g of indodecenyl succinic anhydride were placed in a round-bottomed flask equipped with a thermometer, a stainless steel stirrer, a glass gas inlet tube, and a down-flow condenser. Nitrogen gas was introduced through the inlet tube to raise the temperature of the flask while maintaining an inert atmosphere, and the reaction was carried out at a temperature of 220° C. with stirring.

When water stopped flowing out due to the reaction, the acid value was measured to be 1.5.

Furthermore, 79 g of 1.2.4-benzenetricarboxylic acid anhydride was added and reacted at a temperature of 200°C, and the reaction was terminated when the softening point determined by the ring and ball method reached 130°C to obtain crosslinked polyester C.

Production of non-crosslinked polyester a> 2-2 450 g of bisulfonol A and 120 g of fumaric acid
g and 170 g of terephthalic acid into a round-bottomed flask equipped with a thermometer, stirrer, glass gas inlet tube, and flow-down condenser, set it on a mantle heater, and introduced nitrogen gas through the gas inlet tube. While keeping the inside of the flask in an inert atmosphere, the temperature was raised to 1.
The reaction was carried out at 60° C., and the distilled water was removed. When no more water is distilled out, the temperature is raised to 200℃ and the pressure is reduced to O.
, 95 mmHg and reacted for 10 hours to synthesize non-crosslinked polyester a. The softening point determined by the ring and ball method was 108°C, and the glass transition point was 65°C. ' Example 1 46 parts by weight of the above crosslinked polyester A and 50 parts by weight of magnetite rBL-100J (manufactured by Titan Kogyo Co., Ltd.),
Mixed, kneaded, crushed, and classified to have an average particle size of 12μ
A surrounding binder resin particle powder was obtained.

Next, using Nauta and Turpular, inorganic fine particle powder rR-972J (hydrophobic silica fine particles, average diameter of secondary particles = 0.016 μm, manufactured by Nippon Aerosil Co., Ltd.) was added to the above binder resin particle powder. 4% by weight, organic fine particle powder (polymethyl methacrylate fine particles.

Toner T1 according to the present invention was manufactured by mixing and stirring the following particles (average diameter of secondary particles = 0.5n) at a ratio of 0.4% by weight.

Using this toner T1, an electrophotographic copying machine rU-Bix 1200J (Konishi A photographic test was conducted 50,000 times under normal conditions using a modified machine (manufactured by Rokusha Kogyo Co., Ltd.), and the following items were evaluated.

(1) Image density “Sakura densitometer” (manufactured by Konishiroku Photo Industry Co., Ltd.)
was used to measure and evaluate the maximum image density D1.8 of the copied image.

(2) Image quality The copied images were visually observed and evaluated.

(3) Black Spots The copied images were visually observed to determine the presence or absence of black spots.

(4) Toner transportability The developer layer formed on the developer transport carrier was scraped out and the amount of toner per unit area was measured and evaluated.

(5) Storage stability (blocking resistance) The inside of the toner hopper of the developing device was examined to determine whether or not toner aggregates were generated.

Example 2 Same as Example 1, except that the cross-linked polyester was changed to cross-linked polyester, and the inorganic fine particles were rR-805J (hydrophobic silica fine particles, average diameter of secondary particles = 0.012μ debris 9
Toner T2 according to the present invention was produced in the same manner except that the toner was changed to (manufactured by Nippon Aerosil Co., Ltd.). Using this toner T2, a photographic test was conducted in the same manner as in Example 1, and evaluation was made in the same manner.

Example 3 In Example 1, the crosslinked polyester was changed to crosslinked polyester C, and the inorganic fine particle powder was rR-8124 (hydrophobic silica fine particles, average diameter of -order particles = 0.007 n,
Toner T3 according to the present invention was produced in the same manner except that the toner was changed to (manufactured by Nippon Aerosil Co., Ltd.). This toner T'
A photographic test was carried out in the same manner as in Example 1 using No. 3, and evaluation was made in the same manner.

Comparative Example 1 Comparative toner t1 was prepared in the same manner as in Example 1, except that the crosslinked polyester was changed to non-crosslinked polyester a.
was manufactured. Using this toner t1, a photographic test was carried out in the same manner as in Example 1, and evaluations were made in the same manner.

Comparative Example 2 Comparative toner t2 was produced in the same manner as in Example 1 except that organic fine particles were not used. Using this toner t2, a photographic test was conducted in the same manner as in Example 1, and evaluation was made in the same manner.

Comparative Example 3 Comparative toner t3 was produced in the same manner as in Example 2, except that organic fine particles were not used. Using this toner t3, a photographic test was carried out in the same manner as in Example 1, and evaluation was made in the same manner.

Comparative Example 4 Comparative toner t4 was produced in the same manner as in Example 3 except that organic fine particles were not used. Using this toner t4, a photographic test was carried out in the same manner as in Example 1, and evaluation was made in the same manner.

Example 4 100 parts by weight of the above-mentioned crosslinked polyester and 10 parts by weight of carbon black [Mogul LJ (manufactured by Cabot) were mixed, kneaded, crushed, and classified to obtain particles with an average particle size of 12μ. A coated resin particle powder was obtained.

Next, using Nauta and Turbiniller, inorganic fine particle powder rR-9724 (hydrophobic silica fine particles, average diameter of particles of -0.16μ, manufactured by Nippon Aerosil Co., Ltd.) was added to the above binder resin particles and powder. .4% by weight, inorganic fine particle powder (silicon carbide, 98000.-average particle diameter = 1.QI
0.4% by weight of organic fine particle powder (polymethyl methacrylate fine particles).

Toner T4 according to the present invention was manufactured by mixing and stirring the following particles (average diameter of secondary particles = 0.5 u) at a ratio of 0.4% by weight.

A two-component developer was prepared by mixing 3 parts by weight of this toner with 97 parts by weight of a carrier made of ferrite powder rF-100J (manufactured by Nippon Tetsuko Co., Ltd.) having an average diameter of 120 uyR.

Using this two-component developer, an electrophotographic copying machine for the two-component developer is equipped with a latent image carrier made of a selenium/tellurium photoreceptor and is equipped with a cleaning device having an IJ-ning blade. 'U-Bix 1800J (manufactured by Konishiroku Photo Industry Co., Ltd.) modified machine, 50,000 under normal conditions.
A photographic test was conducted several times, and evaluation was made in the same manner as in Example 1.

Example 5 Toner T5 according to the present invention was produced in the same manner as in Example 4, except that the crosslinked polyester was changed to a crosslinked polyester. Using this toner T5, a photographic test was conducted in the same manner as in Example 4, and evaluation was made in the same manner.

Example 6 Toner T6 according to the present invention was produced in the same manner as in Example 4, except that the crosslinked polyester was changed to crosslinked polyester C. Using this toner T6, a photographic test was conducted in the same manner as in Example 4, and evaluation was made in the same manner.

Comparative Example 5 A comparative toner t was produced in the same manner as in Example 4, except that the crosslinked polyester was changed to non-crosslinked polyester a.
5 was manufactured. Using this toner t5, a photographic test was conducted in the same manner as in Example 4, and evaluation was made in the same manner.

Comparative Example 6 A comparative toner t6 was produced in the same manner as in Example 4, except that the organic fine particles were not used.

Using this toner t6, a photographic test was carried out in the same manner as in Example 4, and evaluation was made in the same manner.

Comparative Example 7 Comparative toner t7 was produced in the same manner as in Example 5, except that organic fine particles were not used.

Using this toner t7, a photographic test was carried out in the same manner as in Example 4, and evaluation was made in the same manner.

Comparative Example 8 Comparative toner t8 was produced in the same manner as in Example 6, except that organic fine particles were not used.

Using this toner t8, a photographic test was conducted in the same manner as in Example 4, and evaluation was made in the same manner.

The above results are shown in Table 1 below.

As can be understood from the above results, according to the toner of the present invention, it is possible to stably form an image with good cleaning properties and no black spots over a large number of times. The toner can be stably transported to the developing area without the filming phenomenon, and the transfer rate is high and images with high image density can be formed. sex)
On the other hand, the comparative toners t1 and t5 have a non-crosslinked polyester binder resin, so toner aggregates tend to occur, making storage difficult. Poor stability (blocking resistance).

Also, comparative toners t2 to t4. Since t6 to t8 do not contain any organic fine particles, the triboelectric charging properties become unstable and the toner conveyance deteriorates, and the physical adhesion of the toner to the latent image carrier is strong, resulting in a low transfer rate. As a result, the image density decreases. Furthermore, since the physical adhesion of the toner to the latent image carrier is strong, poor cleaning occurs and black spots appear on the copied image.

Claims (1)

[Scope of Claims] 1) Obtained by polymerizing a monomer composition containing a trifunctional or higher functional polybasic acid and/or a trifunctional or higher functional polyhydric alcohol,
and comprises binder resin particles made of crosslinked polyester having long-chain aliphatic hydrocarbon units in the main chain and/or side chains, inorganic fine particles, and organic fine particles having a smaller diameter than the binder resin particles. An electrostatic image developing toner characterized by: 2) The toner for electrostatic image development according to claim 1, wherein the organic fine particles have an average diameter of 0.01 to 5 μm. 3) The toner for electrostatic image development according to claim 1 or 2, wherein the inorganic fine particles are made of silica or surface-treated silica. 4) The toner for electrostatic image development according to claim 1, characterized in that the toner contains two or more types of inorganic fine particles. 5) The toner for electrostatic image development according to claim 4, wherein one of the inorganic fine particles is made of silica or surface-treated silica. 6) The toner for electrostatic image development according to any one of claims 1 to 5, wherein the organic fine particles are made of a vinyl polymer. 7) The toner for electrostatic image development according to claim 6, wherein the vinyl polymer is an acrylic polymer. 8) The toner for electrostatic image development according to claim 7, wherein the acrylic polymer is polymethyl methacrylate. 9) The electrostatic agent according to any one of claims 1 to 8, wherein the crosslinked polyester has a long chain aliphatic hydrocarbon unit in its main chain and/or side chain. Toner for image development.