JPS628164A - Toner - Google Patents

Abstract

PURPOSE:To obtain a toner having superior electrifiability and fixability characteristics and to permit development and fixation of a latent image to be improved, by using as a binder a mixture of a cross-linkable polyester and an epoxy resin having an epoxy equivalent of >=1,500 in a specified proportion. CONSTITUTION:The toner powder is prepared by mixing the binder and a toner component and a fluidity improver, and the binder contains the cross-linkable polyester prepared by polymerizing a polyol with a polybasic acid, either containing a tri- or higher-valent functional component, and the epoxy resin having an epoxy equivalent of >=1,500 in an amount of <=95wt%. As said fluidity improver, a surface-treated hydrophobic inorganic oxide selected from titanium oxide, aluminum oxide, and silicon dioxide treated with aminosilane, having particle diameters of <=100mum is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a positively chargeable toner for developing an electrostatic latent image or a magnetic latent image.

[Conventional technology]

Currently, as a method for forming a visible image from given image information, a method using electrostatic latent images is widely used, and a method using magnetic latent images is also being used. . In developing these latent images,
A powdered toner is used which adheres to the latent image and makes the latent image visible.

Such toners are required to have excellent initial properties such as charging properties and fixing properties so that good results can be obtained in each process that the toner undergoes up to the formation of a visible image.

Incidentally, there are many cases in which printed matter formed by toner development must be stored for a long period of time or semi-permanently. In such cases, the printed matter, which has a visible image formed on paper, is usually stored in a so-called document holder made of a resin film, or one or both sides of the printed matter are covered with a laminated resin film. - However, when storage is carried out using such a resin cover, over time, the toner that forms the image sticks to the resin cover that is in close contact with the surface of the printed matter, causing the printed matter to separate from the cover. Then, the toner peels off from the printed matter.
As a result, accidents often occur that actually damage the printed matter.

This is because the resin material used as the storage resin is usually a vinyl chloride polymer and always contains a plasticizer, and this plasticizer acts on the binder resin that makes up the toner to plasticize it. This is thought to be due to putting it away.

Furthermore, in recent years, in order to achieve faster development processing, there has been a demand for toner with excellent fluidity that allows for smooth toner replenishment, toner collection by cleaning after development processing, and the like. Therefore, in order to improve the fluidity of toner, a fluidity improver such as silicon dioxide (silica) is added to toner powder. but,
The fluidity improver is generally used in a mixed state with the toner powder, and since it adheres to the surface of the toner powder and has a large influence on its charging characteristics, the type and amount of the fluidity improver added are important issues.

[Problems to be solved by the invention]

The present invention solves the above-mentioned problems, such as the problem that when a printed matter comes into contact with a resin film such as a vinyl polymer, the toner that makes up the visible image of the printed matter is affected by the resin component and changes in quality. The purpose of the present invention is to provide a toner that is excellent in the following points.

(1) It has excellent charging properties and fixing properties, and can develop and fix a latent image well.

(2) It has high durability against resin and can form visible images with good storage stability.

(3) It has excellent fluidity, and operations such as toner replenishment, collection, and development can be performed smoothly.

[Means for solving problems]

The above problem is solved by the toner containing a toner powder and a fluidity improver formed by dispersing toner components in a binder. resin, the content of the epoxy resin is less than 95% by weight based on the binder, and the fluidity improver is an oxidized epoxy resin having a particle size of 100 mμ or less and subjected to a hydrophobization treatment. The present invention is solved by a toner characterized by: - containing at least one selected from titanium, aluminum oxide, and silicon dioxide surface-treated with aminosilane.

The present invention will be explained in detail below.

In the present invention, a monomer composition consisting of a polyhydric alcohol and a polybasic acid, in which at least one of the polyhydric alcohol and the polybasic acid contains a polyfunctional component having a valence of 3 or more, is obtained by polymerizing the monomer composition. A binder is a mixture of a crosslinkable polyester and an epoxy resin having an epoxy equivalent of 1,500 or more in a specific ratio, and a colorant and other necessary components are added to the binder to form a toner powder. A toner is formed by mixing with a specific fluidity improver.

In the above, examples of dihydric alcohols used in the synthesis of crosslinkable polyester include ethylene glycol, diethylene glycol, triethylene glycol,
．． Diols such as 2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butynediol, 1.4
- bis(hydroxymethyl)cyclohexane, and etherified bisphenols such as bisphenol A1 hydrogenated bisphenol A1 polyoxyethylenated bisphenol A1 polyoxypropylenated bisphenol A,
Others can be mentioned.

Examples of trihydric or higher polyhydric alcohols involved in crosslinking polyester include sorbitol, 1°2.3.6-
Hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2.4-butanetriol, 1
, 2.5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3.5-trihydroxymethylbenzene, and others. can be mentioned.

Examples of polybasic acids used to synthesize crosslinkable polyesters include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, and succinic acid. Acids, adipic acid, sepatic acid, malonic acid, anhydrides of these acids, dimers of lower alkyl esters and riluic acid, and other divalent compounds can be mentioned.

Examples of trivalent or higher polybasic acids involved in crosslinking polyester include 1.2.4-benzenetricarboxylic acid,
1,2.5-benzenetricarboxylic acid, l.

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-methylenecarboxypropane, tetra(methylenecarboxyl)methane, 1,2.7
．． Mention may be made of 8-octane tetracarboxylic acid, embol trimer acid and acid anhydrides thereof, and others.

The trihydric or higher polyhydric alcohol and/or polybasic acid component involved in crosslinking the polyester is contained in a proportion of 5 to 80 mol% in each of the alcohol component or acid component as a structural unit in the polymer. is preferable.

The crosslinkable polyester used in the present invention preferably has an aliphatic hydrocarbon group having 3 to 22 carbon atoms in its side chain.A branched nonlinear crosslinkable polyester is used as described above. This improves the non-offset property of the toner. In order to introduce the aliphatic hydrocarbon group into the crosslinkable polyester, a polybasic acid or a polyhydric alcohol having a divalent or higher valence having the aliphatic hydrocarbon group in its side chain is used as a monomer. As such monomers, for example, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, iso-octylsuccinic acid, n-octylsuccinic acid, etc. can be suitably used. The amount of the divalent or higher polybasic acid and polyhydric alcohol having an aliphatic hydrocarbon group in their side chain is 1 to 50 mol%, preferably 10 to 30 mol%, based on the total monomer component. %. If the amount used exceeds 50 mol %, the non-cohesive properties of the toner will be insufficient, and if the amount used is less than 1 mol %, the low temperature fixing properties of the toner will become insufficient.

The epoxy resin used in the present invention has an epoxy equivalent of 1,500 or more, preferably 1,500 to 3,000. Here, the epoxy equivalent refers to the number of equivalents per epoxy group (g/eq), and specifically, it is the value obtained by dividing the weight average molecular weight by the number of epoxy groups per molecule. The measurement of epoxy equivalent is mainly carried out by direct titration of α-epoxy groups.

Furthermore, the above-mentioned epoxy resin has a melting point of 60 to 160°C, preferably 85 to 120°C, and a glass transition point of 55°C or higher according to the Durand mercury method. Particularly preferred epoxy resins include bisphenol A epoxy resins.

A specific example of an epoxy resin that can be suitably used in the present invention is 1007.
1009 (manufactured by Yuka Shell Epoxy Co., Ltd.), product name r
70 sold as Araldite GY J
97.6097.6099 (manufactured by Ciba Geigy)
, 667 sold under the trade names rD, E, R, J
．． 668 (manufactured by Dow Chemical International), and others.

The content ratio of the above epoxy resin is 9 to the binder.
Less than 5% by weight, preferably 50-90% by weight. The content ratio of epoxy resin to binder is 95%
Exceeding this value tends to cause an offset phenomenon, and bis(4-(2,3-epoxypropoxy)phenyl)propane (CasNo. 1675-), which is contained in epoxy resin and is irritating to human skin, 54-3)
concentration becomes high, which is not preferable.

The toner powder constituting the toner of the present invention is composed of a mixture of the above-mentioned crosslinkable polyester and epoxy resin as a binder, and contains a colorant and a property improver added as necessary to the mixture, and is a magnetic toner. If you do,
A magnetic substance is contained together with or instead of a colorant.

As the coloring agent, carbon black, nigrosine dye<c, 1. No. 50415B), Aniline Blue (C01, No. 50405), Calco Oil Blue (
C.1.No.

azoecBIue 3), chrome yellow (C, r,
No. 14090), Ultramarine Blue (C, 1,
No. 77103>, DuPont Oil Red (C, 1
, No. 26105), quinoline yellow (C, IN
o, 47005), methylene blue chloride (C,
1, No. 52015), Phthalocyanine Blue (
C, r, No. 74160), malachite green offsalate (C, 1, No. 42000), lamp black (C, I, No.

77266), Rose Bengal ('C,'1.No.4
5435), mixtures thereof, and others. These colorants need to be contained in a sufficient proportion to form a visible image with sufficient concentration, and are usually 1 to 20 parts by weight per 100 parts by weight of the binder. .

The magnetic material may be a metal or alloy that exhibits ferromagnetism such as ferrite, magnetite, iron, cobalt, or nickel, or a compound containing these elements, or a material that does not contain a ferromagnetic element but can be prepared by subjecting it to appropriate heat treatment. Mention may be made of alloys which become ferromagnetic, for example alloys of the type called Heusler alloys containing manganese and copper, such as manganese-copper-aluminum, manganese-copper-tin, or chromium dioxide, among others. These magnetic substances are uniformly dispersed in the binder in the form of fine powder with an average particle size of 0.1 to 1 micron. And its content is
The amount is 20 to 70 parts by weight, preferably 40 to 70 parts by weight per 100 parts by weight of toner.

The property improvers include charge control agents, offset inhibitors, and others.

As the fluidity improver constituting the toner of the present invention, an inorganic oxide selected from titanium oxide, aluminum oxide, or silicon dioxide whose surface has been treated with aminosilane is subjected to hydrophobization treatment. These can be used alone or in combination of two or more. In addition,
The reason why silicon dioxide is surface-treated with aminosilane is because silicon dioxide has a strong tendency to be negatively charged, and if it is used as it is, it will have a large effect on the charging characteristics of toners, especially positively chargeable toners. By chemically treating with aminosilane, which has a relatively strong tendency, the influence of silicon dioxide is alleviated.

Specific examples of fluidity improvers that can be suitably used in the present invention include titanium oxide rT-8054 (manufactured by Nippon Aerosil Co., Ltd.).

Average particle size: 301μ), aluminum oxide rRX-CJ (average particle size: 20-μ
), rRA-CJ (manufactured by Nippon Aerosil Co., Ltd.), silicon dioxide rRA surface-treated with aminosilane
-200Hj (manufactured by Nippon Aerosil Co., Ltd.), and others.

The fluidity improver is used in the form of fine particles having a particle size of 100 aaμ or less. The fluidity of the toner depends on the particle size and amount of the fluidity improver added, but if the particle size of the toner exceeds 100 μm, a large amount of fluidity is required to give the toner the desired fluidity. It is necessary to add an improving agent, which tends to cause a decrease in the triboelectric charging properties of the toner.

Further, the addition ratio of the fluidity improver is preferably 0.05 to 0.8% by weight based on the total amount of the toner. If the amount of the fluidity improver added exceeds 0.8% by weight, the charging characteristics of the toner become unstable, which is undesirable.On the other hand, if the amount of the fluidity improver added is less than 0.05% by weight, the The effect of addition cannot be obtained sufficiently.

The hydrophobization treatment performed in the formation of the fluidity improver is carried out by chemically treating with an organosilicon compound, etc., the above-mentioned inorganic oxide that constitutes the fluidity improver, or by chemically adsorbing or chemically adsorbing it to the inorganic oxide. It will be done.

Examples of organosilicon compounds used in such hydrophobization treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, and allyl phenyldichlorosilane. , benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethyl Acetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, octyltrimethoxysilane, diphenyljethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and per molecule 2-1
There are dimethylpolysiloxanes having two siloxane units and one hydroxyl group bonded to Si in the unit located at the end. These can be used alone or in combination of two or more.

The toner of the present invention includes magnetic particles such as iron and ferrite,
A two-component developer is made by mixing with a carrier made of glass beads or the like, or a carrier whose surface is coated with a specific resin to improve its durability, charging characteristics, etc., but it contains a magnetic material. In some cases, it is directly used as a one-component developer to develop electrostatic latent images or magnetic latent images.

〔Example〕

Examples of the present invention will be described below, but the present invention is not limited thereto.

Synthesis Example I (Crosslinkable Polyester A) Polyoxypropylene (2,2)-bis(4-hydroxyphenyl)propane 211g terephthalic acid 299g The flask is placed in a round-bottomed flask equipped with an inlet tube and a flow-down condenser, and the flask is set on a mantle heater. Nitrogen gas is introduced through the gas inlet tube to raise the temperature while maintaining an inert atmosphere inside the flask. Then, 0.05 g of dibutyltin oxide was added, and the reaction was carried out at a temperature of 200° C. while monitoring the reaction at the softening point.

The softening point of the crosslinkable polyester A thus obtained by the ring and ball method (according to the method of IIs K2531-1960; the same applies hereinafter) was 135°C, and the chloroform insoluble content was 17% by weight.

Synthesis Example 2 (Crosslinkable Polyester B) Polyoxypropylene (2,2)-2,2-bis(4-
Hydroquinone 700 g fumaric acid 150 g Dodecenyl succinic anhydride 55.4 g Hydroquinone 0.1 g or more of the substance was prepared using a thermometer, a stainless steel stirrer, a glass gas inlet tube and a down-flow condenser. Place the flask in a mantle heater, introduce nitrogen gas through the nitrogen gas inlet tube to raise the temperature while keeping the inside of the flask in an inert atmosphere, and raise the temperature to 250°C while stirring. The reaction was carried out. When the water produced by the reaction stopped flowing out, the acid value was measured and found to be 1.5.

Furthermore, 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.

The softening point of the crosslinkable polyester B thus obtained was 128°C by the ring and ball method.

Synthesis Example 3 (Crosslinkable Polyester C) Polyoxypropylene (2,2)-2,2-bis(4-
Hydroxyphenyl)propane 650g fumaric acid 120g isododecenylsuccinic anhydride 55.4g or more of the following substances:
Place the flask in a round-bottomed flask equipped with a thermometer, stainless steel stirrer, glass gas inlet tube, and flow-down condenser, set the flask on a mantle heater, and introduce nitrogen gas through the gas inlet tube to fill the inside of the flask. While maintaining an inert atmosphere, the temperature was increased to 220°C while stirring.
The acid value was measured at the time when the water produced by the zero reaction, which was carried out at 0.degree. C., stopped flowing out, and it was found to be 1.5.

Further, 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 according to the ring and ball method reached 130°C.

Example 1 Crosslinkable polyester 8 30 parts by weight Epoxy resin "Epikote 1007 J (Epoxy 12051
) 70 parts by weight polypropylene [Viscol 660PJ (manufactured by Mitsubishi Kasei Corporation) 3 parts by weight Carbon blank r"30J (manufactured by Mitsubishi Kasei Corporation) 6 parts by weight Charge control agent "Bontron N-11J (manufactured by Orient Chemical Co., Ltd.) 3 parts by weight
The mixture according to the prescription of more than 1 part by weight was prepared in a Henschel mixer for 15 minutes, and then melt-kneaded with a two-wheeled extruder. After being cooled to room temperature and solidified, it was coarsely crushed using a hammer mill, and then finely crushed using a type 1 mill. The obtained fine powder was classified using a wind classifier, and the particle size was 10.4 to 11.8μ.
I got a fake toner powder.

Then, a fluidity improver rRX-Cl corresponding to 0.25% by weight of the toner powder was added and mixed to obtain a toner.

Example 2.3 and Comparative Example 1.2 Various toners were obtained in the same manner as in Example 1 according to the following procedure.

Example 2 Crosslinkable polyester A 20 parts by weight Epoxy resin "Epikote 1007 J" 80 parts by weight Polypropylene "VISCOL 660PJ 3 Heavy IT part carbon black R" 30J 6 parts by weight Charge control agent "Bontron N-2J (manufactured by Orient Chemical Co., Ltd.) 3 Part by weight Flowability improver rT-805J O, 4% by weight
Example 3 Crosslinkable polyester C 40 parts by weight Epoxy resin [Epicoat 1007460 parts by weight Polypropylene "Viscol 660PJ 3 Heavy IE parts Carbon black RL 30J 5 parts by weight Charge control agent "Bontron N-2J 3 parts by weight Flowability improver rRA-200HJ O , 4% by weight Comparative Example 1 Instead of the fluidity improver in Example 1, fine silicon dioxide powder rR-812J (manufactured by Nippon Aerosil Co., Ltd.) was hydrophobized with hexamethyldisilazane.
A toner was prepared in the same manner as in Example 1 except that 0.25% by weight was used.

Comparative Example 2 Instead of the fluidity improver in Example 3, a fine powder of silicon dioxide rR-972J (manufactured by Nippon Aerosil Co., Ltd.) 0.
A toner was prepared in the same manner as in Example 3 except that 4% by weight was used.

Each of the above toners was tested for the following items.

(1) Charging characteristics Each of the above toners and 100 to 200 meshes of conductive spherical carrier were mixed to prepare a developer having a toner concentration of 2.0% by weight. A shaking machine rNe shakes each of these developers.
After mixing for 1 minute with w-YSJ (manufactured by Yayoi),
The charge amount Q/M per unit weight (unit: 2 microcoulombs/g) of the toner was measured by a blow-off method. Further, the mixing time was set to 10 minutes, and the charge iiQ/M (unit: microcoulomb/g) per unit weight of the toner was measured in the same manner, and the charge increased due to friction (hereinafter referred to as "rise of charge"). We considered whether or not this could be carried out promptly.

(2) Softening point The softening point of each toner was measured using a Koka type flow tester rcTP.
-500J (manufactured by Shimadzu Corporation).

3) Fixing properties A developer having a toner concentration of 2.5% by weight was prepared by mixing each of the toners with 100 to 20 meshes of carrier consisting of iron powder coated with styrene-acrylic resin. , each of which produces an electrophotographic copying machine "υ-Bj
x 4500J (manufactured by Konishiroku Photo Industry Co., Ltd.), we conducted a photo-printing test using the steps of developing an electrostatic latent image, transferring the toner image to transfer paper, and fixing the toner image with a heated roller fixing device. For each, the minimum fixing temperature and offset occurrence temperature were determined.

(i) Minimum fixing temperature Regarding the minimum fixing temperature, the surface layer is made of Teflon (polytetrafluoroethylene manufactured by DuPont) and the surface layer is made of silicone rubber rKE-1300RTVJ.
A fixing device consisting of a pressure roller (manufactured by Shin-Etsu Chemical Co., Ltd.) was used to fix the toner image of the sample toner transferred onto a 64 g/rd transfer paper at a high linear speed of 350 m/7 seconds. Set temperature to 100℃
The temperature is then raised stepwise by 10°C and repeated at each temperature, and the formed fixed image is subjected to Kimwipe rubbing, and the lowest set temperature for a fixed image that exhibits sufficient rubbing resistance is determined as the minimum fixing temperature. did. Note that the fixing device used here does not have a silicone oil supply mechanism.

(ii) Offset generation temperature To measure the offset generation temperature, transfer the toner image and perform the fixing process using the above-mentioned fixing device, and then transfer a blank transfer paper to the fixing device under the same conditions. The operation of sending it to the printer and observing whether or not toner stains occur thereon is repeated while the set temperature of the heat roller of the fixing unit is successively increased, and the offset generation temperature is determined at the lowest set temperature at which toner stains occur. And so.

(4) Resin durability vs. resin durability was determined by placing a commercially available polyvinyl chloride cover film in close contact with the surface of a printed matter formed by a continuous copy test, applying a load of 100 g/cs'', and applying a load of 100 g/cs, at a temperature of 70°C. Regarding the results of the 0 judgment, the cover film was peeled off from the printed matter after being left in an atmosphere of , "O" indicates that no metastasis is observed, "△" indicates that a small amount of metastasis is observed, and "x" indicates that metastasis is observed.

(5) DGBA Concentration The content ratio of DGBA contained in the epoxy resin in each toner was measured by liquid chromatography. The sample used at this time was obtained by extracting 200 mg of toner sample in 50 ml of methanol for 5 hours.

Since DGBA is irritating to human skin, it is desired that its content be as low as possible, and as a standard, it is preferably 1% or less.

The above results are shown in Table 1.

As is clear from the results in Table 1, in the examples of the present invention, good results were obtained across all evaluation items, but in the comparative examples, insufficient results were obtained in any of the evaluation items. It was done.

That is, in the comparative examples, all fluidity improvers were composed of silicon dioxide that had just been subjected to a hydrophobization treatment,
This tends to be more negatively charged than the toner and inhibits the positive charging properties of the toner, so that the rise in charging of the toner due to friction is slow and it is difficult to obtain a predetermined amount of charge. As a result, the occurrence of toner scattering, capri, etc. was significant, and it was difficult to perform development and fixing to the extent required for practical use.

〔Effect of the invention〕

As described above, in the toner of the present invention, toner powder is prepared using a blend of a specific crosslinkable polyester and an epoxy resin in a specific ratio as a binder, and this toner powder is mixed with a specific fluidity improver. Because it is formed as a developer, it has excellent properties as a developer, especially excellent developability, fixing performance, and fluidity, and can form good visible images, as well as high resistance to resin. Even if a cover such as a resin film is provided for preservation or other purposes, it will not be adversely affected by this.
Therefore, a visible image is formed that can be stored semi-permanently.

Hereinafter, the effects of the present invention will be specifically explained.

(1) Excellent charging characteristics.

Generally, polyester resins have strong negative chargeability, but in the present invention, by mixing an epoxy resin with crosslinkable polyester, the negative chargeability of the polyester resin itself is weakened, and the toner becomes negatively charged. It becomes less sexual. As a result, for example by selecting a carrier or by including a suitable charge control agent, it is possible to use a toner that is to be developed with a positively charged toner, for example when developing an electrostatic latent image formed by a negative charge, or with a laser. It is also very advantageously used in reversal development of a positive electrostatic latent image formed using a selenium photoreceptor with excellent photoconductivity as a latent image support as in a printer.

(2) Excellent fixing properties.

Since polyester resin generally has a low softening point, toners using polyester resin as a binder are characterized by a low temperature required for fixing. The crosslinkable polyester used as a binder in the present invention is made of a monomer composition containing a trifunctional or higher polyfunctional component, and has a molecularly branched and crosslinked structure. While retaining the low-temperature fixing properties characteristic of such polyester resins, the off-cent phenomenon during fixing is less likely to occur. Furthermore, epoxy resin also greatly contributes to lowering the softening point of toner.

Therefore, by fixing the toner image using the hot roller fixing method, which has many advantages, sufficient fixing can be achieved at high speed and with less energy consumption.

(3) Excellent durability against resin.

The crosslinkable polyester and epoxy resin used as the binder in the present invention both have excellent chemical resistance, so that when the toner of the present invention comes into contact with a resin such as a vinyl chloride polymer that is normally used as a storage cover, Furthermore, it is less susceptible to the effects of plasticizers contained in this resin, and therefore can form toner images with good storage stability.

(4) Excellent durability.

The cross-linked polyester and epoxy resin used as the binder in the present invention both have excellent mechanical strength, and by using a blend of these, the toner of the present invention has excellent impact resistance, and therefore can last for a long time. Good images can be formed.

(5) Excellent fluidity.

The toner of the present invention has excellent fluidity because it contains a fluidity improver made of a specific fine inorganic oxide, and therefore can perform smooth toner transportation, and can be used for toner replenishment, collection, etc. It is possible to effectively achieve speed-up of processing operations and simplification of equipment. Moreover, the fluidity improver used in the present invention has a small negative charging tendency and is similar to the charging tendency of positively charging toner.
It is extremely unlikely to affect the charging characteristics of the toner and inhibit its function.

S+Nia.

Claims (1)

[Scope of Claims] 1) A toner comprising a toner powder formed by dispersing toner components in a binder and a fluidity improver, wherein the toner powder includes a binder containing a crosslinkable polyester and an epoxy equivalent of 1500 or more. epoxy resin, and the content of the epoxy resin is less than 95% by weight based on the binder, and the fluidity improver is an oxidized epoxy resin having a particle size of 100 mμ or less and subjected to a hydrophobic treatment. A toner comprising at least one selected from titanium, aluminum oxide, and silicon dioxide surface-treated with aminosilane. 2) The toner according to claim 1, wherein the crosslinkable polyester is obtained by polymerizing a monomer composition containing a trifunctional or higher functional polybasic acid and/or a trifunctional or higher functional polyhydric alcohol. 3) Crosslinkable polyester has 3 to 22 carbon atoms in its side chain.
The toner according to claim 1, having an aliphatic hydrocarbon group. 4) The content of fluidity improver is 0.05 to 0.8% by weight
The toner according to claim 1.