CN100435032C - Electrophotographic toner, polyester resin used therefor, method for their production, electrophotographic developer, and image forming method - Google Patents

Abstract

The present invention provides a binder resin for an electrophotographic toner, an electrophotographic toner using the resin, and a method for producing the electrophotographic toner, as well as an electrophotographic developer and an image forming method. The binder resin contains about 1 to 10000 ppm of rare earth elements, and is preferably composed of polyester resin. The polyester resin is preferably obtained from an acid unit having a dicarboxylic acid group and a compound having a diol group by using a heterogeneous catalyst that supports a rare earth metal trifluoromethanesulfonate or a rare earth metal trifluoromethanesulfonimide salt on a carrier. Group of alcohol units to synthesize.

Description

Electrophotographic toner, polyester resin used therefor, method for their production, electrophotographic developer, and image forming method

technical field

The present invention relates to a binder resin for electrophotographic toner, an electrophotographic toner using the binder resin, a production method thereof, an electrophotographic developer and an image forming method, the electrophotographic toner The agent can be used in an electrophotographic apparatus such as a copying machine, a printer, or a facsimile machine using an electrophotographic method.

Background technique

Many electrophotographic methods are known (for example, see Japanese Patent Publication Sho 42-23910). Generally, an electric latent image is formed on the surface of a photoreceptor (latent image holder) using a photoconductive material through multiple processes using various means, and then the formed latent image is developed using a toner to form a toner. After the toner image is formed, the toner image on the surface of the photoreceptor is transferred to the surface of a transfer-receiving material such as paper with or without an intermediate transfer body, and the The transferred image is fixed to form a fixed image. If necessary, the toner remaining on the surface of the photoreceptor is removed by various methods and supplied again to the above-mentioned various processes.

As a fixing technique for fixing an image transferred onto the surface of a transfer-receiving material, a heat roller fixing method in which a transfer-receiving material on which a toner image is transferred Between a pair of rollers of heating roller and pressure roller. In addition, as a similar technique, a method consisting of replacing one or two rollers with one belt or a plurality of belts is also known. Compared with other fixing methods, these technologies can produce strong fixed images at high speed, are more energy efficient, and cause less damage to the environment due to volatilization of solvents and the like.

On the other hand, in order to reduce the energy used by a copier or a printer, a technology capable of fixing toner with lower energy is required. Therefore, there is a strong need for electrophotographic toners capable of fixing at lower temperatures.

As a method of lowering the fixing temperature of the toner, a method of lowering the glass transition temperature of the toner resin (binder resin) is used. As the toner binder resin, polyester can be used, and particularly for electrophotography, a crystalline polyester resin is used. The polyester contains acid and hydroxyl groups and is susceptible to its environment, especially humidity. As an effort to improve chargeability, a proposal has been disclosed to lower the acid value of the resin (Japanese Patent Laid-Open No. 62-291668), and the use of organic fluorides has been proposed (Japanese Patent Laid-Open No. 11-24306 or Japanese Patent Laid-Open No. 2003-107802) ; However, the chargeability of these substances is insufficient.

Furthermore, as a toner using a rare earth element compound, there is disclosed an α-Si photoreceptor, a one-component magnetic toner, and a combination of a fluorinated rare earth element compound and an oxidized rare earth element compound (for example, Japanese Patent Laid-Open No. 2002-311769 and JP-A-2002-311639). Furthermore, a toner using a binder resin and a toner using cerium oxide and a rare earth element compound as an external additive are disclosed (for example, Japanese Patent Laid-Open No. 2002-314587 and Japanese Patent Laid-Open No. 2001-265057).

All these examples use a method in which a rare earth compound is externally added to the surface of the toner and used to improve cleaning defects.

On the other hand, recently, energy-saving production methods have been proposed in consideration of reducing environmental burdens (reduction of CO ₂ gas). In the field of electrophotography (eg, Japanese Patent Laid-Open No. 10-26842), there is a strong demand in the market for reducing energy used for producing toner and reducing energy used by printers or copiers in view of energy saving.

As a production method of toner, it has been developed from conventional methods such as melt-kneading, pulverization and classification to suspension polymerization method and melt-suspension method, and from the viewpoint of production energy, it is moving toward reducing its energy consumption.

However, the energy required to produce toner resins has not been sufficiently reduced.

Specifically, for polyester resins, which can reduce fixing energy, a large amount of energy is still consumed in the production of polyester resins compared to vinyl polymer resins. Therefore, the total energy consumption in producing resins and toners is enormous.

For example, in the production of toner resins, until now, tin-based catalysts including dibutyltin oxide and titanium-based catalysts including titanium dioxide have been generally used. As catalysts for polymerizing polyesters, dihydrocarbyl tin oxides, dihydrocarbyl tin carboxylates, hydroxy monohydrocarbyl tin oxides, and dihydrocarbyl distannoxanes have been used as catalysts for polyester resins. For example, in JP-A 51-61595 and JP-A 62-87248, a polymerization method using dihydrocarbyl distannoxane is proposed, and in JP-A 03-188047 and JP-A 04-288041, it is proposed to use Polymerization method of organotin. However, when these methods are used to produce high-molecular-weight polymers required for imparting viscoelasticity and durability to toners, there are problems in that high temperature (150° C. or higher) and low vacuum reaction conditions are required, and during the reaction It is difficult to recover and reuse the catalyst. Therefore, it is difficult to regard these methods as sufficiently satisfying the needs industrially.

As a method of overcoming the catalyst recovery problem, for example, Japanese Patent Laid-Open No. 2003-335727 proposes a method of performing polymerization using two solvents and extracting the catalyst in one solvent layer. However, special fluorinated solvents are required in this method. Furthermore, since Lewis acid is used as a catalyst used in polycondensation, the catalyst is hydrolyzed and it is difficult to recover and reuse.

On the other hand, the present inventors have synthesized a polyester resin by using a rare earth triflate catalyst, and tried to prepare a toner using the polyester resin. However, this toner was found to have a disadvantage in that the long-term storage of images was poor. In addition, it was also found that the fixing strength became poor because of the presence of low molecular weight components in the polyester resin.

Contents of the invention

The present invention provides a binder resin for an electrophotographic toner, and can obtain an electrophotographic toner having excellent long-term image storage properties, high fixing strength, And have excellent image formation and/or charging stability. In particular, the present invention provides a method for producing a polyester resin for electrophotographic toner and a polyester resin obtained thereby, according to which a heterogeneous catalyst can be easily recovered. Furthermore, the present invention provides an electrophotographic toner comprising the binder resin and a method for producing the same. In addition, the present invention provides an electrophotographic developer including the electrophotographic toner and an image forming method using the electrophotographic toner.

That is, the present invention provides an electrophotographic toner including a binder resin and a colorant, wherein the binder resin includes about 1 ppm to 10000 ppm of a rare earth element.

The present invention further provides a method of producing the electrophotographic toner, the method comprising: mixing a particle dispersion of a binder resin and a particle dispersion of a colorant so that the binder resin particles and the colorant particles agglomeration; the aggregated particles are heated to a temperature equal to or higher than the glass transition temperature or melting point of the binder resin to fuse the aggregated particles.

The present invention further provides an image forming method, the method comprising: forming an electrostatic latent image on the surface of a latent image holder; image development to form a toner image; transfer the toner image formed on the surface of the latent image holder to the surface of the transfer-receiving material; and transfer the toner to the surface of the transfer-receiving material A developer image is thermally fixed, wherein the developer includes a carrier and the electrophotographic toner.

An electrophotographic toner of one embodiment of the present invention contains a polyester resin, preferably a polyester resin synthesized by using a specific heterogeneous catalyst, as a binder resin. Therefore, an image formed from the toner has excellent fixing strength and storability.

Furthermore, in the production method of the polyester resin for electrophotographic toner according to another embodiment of the present invention, the heterogeneous catalyst used can be easily recovered and reused after synthesis.

Detailed ways

Hereinafter, the binder resin, electrophotographic toner, production method thereof, electrophotographic developer, and image forming method of the present invention will be described in detail.

binder resin

The binder resin of the present invention contains about 1 ppm to 10000 ppm of rare earth elements. The binder resin of the present invention is preferably used as a binder resin contained in an electrophotographic toner. In the present invention, ppm refers to parts per million by mass.

In the binder resin of the present invention, in the case where the binder resin of the present invention is used in an electrophotographic toner, when the rare earth element content is less than about 1 ppm, the toner is not charged. Therefore, a clear image cannot be obtained sometimes.

On the other hand, when the rare earth element content is greater than about 10000 ppm, fogging or background staining sometimes results because the toner is excessively charged.

The content of rare earth elements in the binder resin of the present invention is preferably about 5 ppm to 5000 ppm.

The kind of the rare earth element contained in the binder resin of the present invention is not limited to a specific kind, but is preferably Sc, Y, Yb or Sm, more preferably Sc.

The kinds of rare earth elements contained in the binder resin of the present invention may be one kind or two kinds or more than two kinds. When the binder resin of the present invention contains two or more rare earth elements, the sum of the two or more rare earth elements is taken as the content of the rare earth elements.

As a method of incorporating a rare earth element into the binder resin of the present invention, a method of adding a rare earth metal compound at the time of synthesizing the binder resin of the present invention or producing an electrophotographic toner according to the method described below can be used. As rare earth metal compounds, inorganic salts such as oxides, hydroxides, ketoates, acetates, oxalates, thiocyanates, cyanates, borides, silicides, sulfates, chlorides can be used and fluoride.

In the case of adding a rare earth metal compound when synthesizing the binder resin of the present invention, a method of using a catalyst containing a rare earth element as the rare earth metal compound and leaving the catalyst in the binder resin is preferably used.

In addition, the rare earth element can be incorporated into the binder resin by heating and melting the binder resin, and adding thereto a compound containing the rare earth element, followed by stirring.

The binder resin of the present invention is not particularly limited as long as it contains about 1 ppm to 10000 ppm of rare earth elements, but the binder resin is preferably a polyester resin, more preferably a crystalline polyester resin. When the crystalline polyester resin is used, the fixing performance to paper is improved, and in addition, toner blocking resistance, image storage and low-temperature fixing performance are improved.

The binder resin of the present invention is preferably synthesized using a catalyst represented by the following general formula (1).

General formula (1)X(OSO ₂ CF ₃ ) ₃

In the general formula (1), X represents a rare earth element, and among the rare earth elements, it is preferably Sc, Y, Yb or Sm.

In addition, it is preferable to use a catalyst represented by the following general formula (2) to synthesize the binder resin of the present invention.

General formula (2)X(N(SO ₂ CF ₃ ) ₂ ) ₃

In the general formula (2), X represents Sc, Y, Yb or Sm.

When the synthesis is performed using a catalyst represented by the general formula (1) or (2), rare earth elements may be incorporated into the binder resin.

A catalyst represented by the general formula (1) or (2) may be preferably used for synthesizing the polyester resin.

Polyester resin synthesis in which a catalyst represented by the general formula (1) or (2) is used will be described below.

The amount of the catalyst used is preferably about 0.01% by mass to 10% by mass relative to the resin produced. When it is less than the above amount, the condensation polyesterification reaction becomes slow, and when it exceeds the above amount, the charge amount and the like are adversely affected.

The catalyst enables polycondensation to be carried out at a lower temperature than tin-based catalysts and titanium-based catalysts used in the past. Specifically, in order to obtain a polyester resin with a weight-average molecular weight Mw of 20,000 within the same time interval, existing catalysts require a reaction temperature of about 180° C. or above, while the resin of the present invention can be produced at a temperature equal to or lower than about 150° C. obtained at a temperature of 150 °C.

When the catalyst represented by the general formula (1) or (2) is used, the energy required for producing the polyester resin can be reduced.

The production method of the polyester resin is not particularly limited. A generally known method for polyester polymerization in which acid units (acid monomers or acid polymers) and alcohol units (alcohol monomers or alcohol polymers) are reacted can be used. For example, depending on the type of monomer, direct polycondensation method, transesterification method, etc. can be used. In addition, the reaction form of the polymerization is not particularly limited, and may be solution polymerization, block polymerization, or the like. However, block polymerization is preferred. Furthermore, in the case of employing block polymerization, it is important to reduce the reaction pressure to an appropriate level in order to promote dehydration. In the present invention, the reaction can advantageously proceed when the pressure is reduced to about 40 mmHg or below.

When the acid unit and alcohol unit are reacted, the molar ratio (acid unit/alcohol unit) which varies depending on reaction conditions and the like cannot be generalized; however, it is usually about 1/1. In this catalyst, the optimum temperature for polymerization in the present invention is about 120°C or lower, although the higher the reaction temperature, the more the esterification reaction proceeds.

The polyester resin is preferably synthesized from acid units having dicarboxylic acid groups and alcohol units having diol groups. In the polyester resin, the constituent site that is an acid unit before synthesizing the polyester resin is referred to as "acid-derived component" in the description below, and the constituent site that is an alcohol unit before synthesizing the polyester resin is referred to as "acid-derived component" in the description below. "Alcohol Derived Component".

As the binder resin in the present invention, a crystalline polyester resin is preferable. If the polyester resin is not crystalline, that is, if the polyester resin is amorphous, it is sometimes difficult to maintain toner blocking resistance and image storage properties while ensuring excellent low-temperature fixing performance.

In the present invention, the "crystallinity" of the "crystalline polyester resin" means that there is no stepwise change in the heat of absorption in differential scanning calorimetry (DSC), but a distinct absorption peak. Furthermore, in some cases, if a crystalline polyester resin is added to the toner, the absorption peak may be a peak having a width of about 40°C to 50°C. In the case of a polymer in which other components are copolymerized into the main chain of the crystalline polyester, if the content of the other components is 50% by mass or less, the copolymer is also called a crystalline polyester.

In particular, the electrophotographic toner of the present invention contains at least a binder resin and a colorant, and the binder resin is preferably a polyester resin synthesized using a heterogeneous catalyst in which rare earth metal trifluoromethanesulfonic acid Salt or rare earth metal trifluoromethanesulfonimide salt is loaded on the carrier.

The polyester resin for electrophotography used in the electrophotographic toner of the present invention is preferably crystalline. The heterogeneous catalyst supported on a support by said rare earth metal trifluoromethanesulfonate or rare earth metal trifluoromethanesulfonimide salt and used for synthesizing the polyester resin used in the electrophotographic toner of the present invention is preferably Represented by general structural formula (1) or (2).

As a method for supporting a rare earth metal trifluoromethanesulfonate catalyst or a rare earth metal trifluoromethanesulfonimide salt catalyst on a carrier, a rare earth metal trifluoromethanesulfonate or a rare earth metal trifluoromethanesulfonimide salt can be used A method of using after fixation on a support such as polystyrene resin (J. Am. Chem. Soc. 1998, vol. 120, pp. 2985-2986). In addition, it can be chemically bonded to a support such as a phosphine resin and used. Alternatively, it can be encapsulated in microcapsules as a carrier.

As the carrier of the heterogeneous catalyst in the present invention, inorganic material carriers such as carbon powder, alumina, silica, carbonates and halides of calcium, carbonates and halides of magnesium, and zeolites, and polymers such as Organic material supports such as polystyrene, polyvinylpyrrolidone, polyaniline, polyphosphine, and polyethylene glycol.

The catalysts used in the synthesis of the polyester resins of the present invention are insoluble in solvents. Therefore, the produced resin and catalyst can be easily separated and recovered, and the recovered catalyst can be reused.

Specifically, any solvent that can dissolve the polyester resin may be added to the reaction product so that only the polyester resin is dissolved, followed by filtration or centrifugation, whereby the undissolved catalyst remaining in the solvent can be easily separated from the polyester resin solution. separate. Growths on the surface of the catalyst can be easily removed by washing the catalyst with a suitable solvent. Any solvent may be used as long as it can dissolve the polyester resin, and examples include chloroform, xylene, benzene and toluene.

On the other hand, if the polyester resin is dropped into a poor solvent and precipitated again, it can be purified and recovered.

The polyester resin for electrophotographic toner of the present invention is preferably a crystalline polyester resin. If the polyester resin is crystalline, toner blocking prevention and image storability can be maintained while ensuring excellent low-temperature fixing performance. In the present invention, the "crystallinity" of "crystalline polyester resin" means that there is no stepwise change in the heat of absorption in differential scanning calorimetry (DSC), but a clear absorption peak appears. In addition, when the crystalline polyester resin is added to the toner, sometimes this absorption peak may be a peak with a peak width of about 40°C to 50°C. In the case of a polymer in which other components are copolymerized to the main chain of the crystalline polyester, if the content of the other components is 50% by mass or less, the copolymer is also called a crystalline polyester.

Then, the "acid-derived component" and "alcohol-derived component" in the polyester resin of the present invention will be explained. The "acid-derived component" means a constituent site of an acid unit before synthesizing a polyester resin, and the "alcohol-derived component" means a constituent site of an alcohol unit before synthesizing a polyester resin.

acid derived components

As the acid constituting the acid-derived component, various dicarboxylic acids can be used. However, as the acid-derived component in the polyester resin of the present invention, aromatic dicarboxylic acids and aliphatic dicarboxylic acids are preferred, among which aliphatic carboxylic acids are preferred, and linear dicarboxylic acids are particularly preferred.

Aliphatic dicarboxylic acids include, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decane dicarboxylic acid, 1,11-undecane dicarboxylic acid, 1,12-dodecane dicarboxylic acid, 1,13-tridecane dicarboxylic acid, 1,14-tetradecane Dicarboxylic acid, 1,16-hexadecanedicarboxylic acid and 1,18-octadecanedicarboxylic acid and their lower alkyl esters and anhydrides, but not limited thereto. Among them, sebacic acid and 1,10-decanedicarboxylic acid are preferable in view of availability.

As the aromatic dicarboxylic acid, for example, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid and 4,4'-biphenyl dicarboxylic acid can be used in consideration of easy availability and low formation Ease of melting point polymers, preferably terephthalic acid.

As the acid-derived component, in addition to the aliphatic dicarboxylic acid-derived component and the aromatic dicarboxylic acid-derived component, it is preferable to contain, for example, a dicarboxylic acid-derived component having a double bond and a dicarboxylic acid-derived component having a sulfonic acid group. Grading components.

The dicarboxylic acid-derived component having a double bond includes a component derived from a lower alkyl ester or anhydride of a dicarboxylic acid having a double bond in addition to a component derived from a dicarboxylic acid having a double bond. In addition to the components derived from dicarboxylic acids having sulfonic acid groups, the dicarboxylic acid derived components having sulfonic acid groups also include components derived from lower alkyl esters or acid anhydrides of dicarboxylic acids having sulfonic acid groups .

A dicarboxylic acid having a double bond and capable of crosslinking the entire resin with its double bond may be preferably used for preventing hot ink smearing at the time of fixing. As such a dicarboxylic acid, for example, fumaric acid, maleic acid, 3-hexenedioic acid, 3-octenedioic acid and the like can be used, but not limited thereto. In addition, their lower alkyl esters and anhydrides can be used. Among them, fumaric acid and maleic acid are preferable in consideration of cost.

A dicarboxylic acid having a sulfonic acid group is effective because it can improve dispersion of colorants such as pigments and the like. In addition, when the whole resin is emulsified or suspended in water to prepare particles, if a sulfonic acid group is present, emulsification or suspension can be achieved without using a surfactant as described below. As such a dicarboxylic acid having a sulfonic acid group, for example, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, sulfosuccinic acid sodium salt, etc. can be used, but not limited to these compounds. In addition, lower alkyl esters and anhydrides of these compounds may be used. Among them, 5-sulfoisophthalic acid sodium salt is preferable in consideration of cost.

Acid-derived components other than aliphatic dicarboxylic acid-derived components and aromatic dicarboxylic acid-derived components (dicarboxylic acid-derived components having double bonds and dicarboxylic acid The derivative component) content is preferably about 1 to 20 composition mol%, more preferably about 2 composition mol% to 10 composition mol%.

When the content is less than about 1 composition mol%, the pigment dispersibility becomes poor, the emulsion particle diameter becomes large, and sometimes it becomes difficult to control the toner diameter due to aggregation. On the other hand, when it exceeds about 20 composition mol%, the crystallinity of the polyester resin deteriorates; the melting point lowers; the image storage property deteriorates; and the emulsion particle diameter becomes small enough to dissolve in water, resulting in failure to form a latex sometimes. In this specification, "composition mol%" refers to a percentage when each component (acid-derived component and alcohol-derived component) in the polyester resin is defined as a unit (in moles), respectively.

Alcohol derived components

As the alcohol constituting the alcohol-derived component, an aliphatic diol is preferable, and a straight-chain type aliphatic diol having 7 to 20 carbon atoms is more preferable. When the aliphatic diol is of a branched type, the crystallinity of the polyester resin is deteriorated and the melting point is lowered, whereby toner blocking resistance, image storability and low-temperature fixing performance sometimes deteriorate.

Furthermore, when the number of carbon atoms contained in the chain is less than 7, in the case of polycondensation of the alcohol with an aromatic dicarboxylic acid, sometimes the melting point becomes high and low-temperature fixing becomes difficult. On the other hand, when it exceeds 20, raw materials are practically difficult to obtain. The number of carbon atoms contained in the chain is preferably 14 or less.

Furthermore, when the polyester resin is obtained by polycondensation with an aromatic dicarboxylic acid, the number of carbon atoms contained in said chain is preferably an odd number. When the number of carbon atoms contained in the chain is an odd number, the melting point of the polyester resin will be lower than that of a polyester resin having said chain having an even number of carbon atoms, and the melting point can be easily brought into the range described below.

Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol Alcohol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13- Tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol and 1,20-eicosanediol. However, the aliphatic diol is not limited thereto. Among them, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability, and 1,9-nonanediol is preferable in view of lowering the melting point.

In the alcohol-derived component, the content of the aliphatic diol-derived component is about 80 composition mol% or more, and other components may be contained if necessary. In the alcohol-derived component, the content of the aliphatic diol-derived component is preferably about 90 composition mol% or more.

When the content of the aliphatic diol-derived component is less than about 80 composition mol%, the crystallinity of the polyester resin is deteriorated and the melting point is lowered, thereby sometimes causing deterioration in toner blocking resistance, image storage and low-temperature fixing performance. Examples of other components added as needed include a diol-derived component having a double bond and a diol-derived component having a sulfonic acid group.

Examples of the diol having a double bond include 2-butene-1,4-diol, 3-hexene-1,6-diol, 4-octene-1,8-diol and the like. Examples of diols having sulfonic acid groups include 1,4-dihydroxy-2-benzenesulfonic acid sodium salt, 1,3-dimethylol-5-benzenesulfonic acid sodium salt, 2-sulfo-1,4 -butanediol sodium salt, etc.

In the case of adding an alcohol-derived component other than an aliphatic diol-derived component (a diol-derived component having a double bond and a diol-derived component having a sulfonic acid group), the content thereof is preferably the entire alcohol-derived component About 1 to 20 composition mol% of the composition, more preferably 2 composition mol% to 10 composition mol%.

When the content of the alcohol-derived component other than the aliphatic diol-derived component is less than about 1 composition mol%, the pigment dispersibility becomes poor, the emulsion particle diameter becomes large, and sometimes it becomes difficult to control the toner diameter due to aggregation . On the other hand, when it exceeds 20 composition mol%, the crystallinity of the polyester resin deteriorates; the melting point lowers; the image storage property deteriorates; the emulsion particle diameter becomes small enough to dissolve in water, resulting in failure to form a latex sometimes.

The melting point of the crystalline polyester resin is preferably about 60°C to 120°C, more preferably about 70°C to 100°C. When the melting point is lower than about 60° C., sometimes the powder tends to aggregate, and the storability of the fixed image deteriorates. On the other hand, when it exceeds about 120°C, the properties of the crystalline polyester resin deteriorate.

The melting point of the amorphous polyester resin is preferably about 50°C to 100°C, more preferably about 60°C to 80°C. When the melting point is lower than about 50° C., sometimes the powder easily aggregates, and the storability of the fixed image deteriorates. On the other hand, when it exceeds about 100°C, the characteristics of the amorphous polyester resin deteriorate.

In addition, among polyester resins, biodegradable polyester resins may be used.

Colorant

The colorant of the toner of the present invention is not particularly limited. Conventionally known colorants can be used and appropriately selected according to the application. One kind of pigment may be used alone, or two or more similar types of pigments may be mixed and used in combination. Alternatively, two or more pigments formed of different base materials may be used in combination. Specific examples of the colorant include: carbon black such as furnace black, channel black, acetylene black, or thermal black; inorganic pigments such as ferrite, aniline black, Prussian blue, titanium white, or magnetic powder; azo pigments , such as fast yellow, monoazo yellow, disazo yellow, pyrazolone red, chelate red, brilliant magenta (such as 3B or 6B) or coupled brown; phthalocyanine pigments such as copper phthalocyanine or non-metallic phthalocyanine cyanine; and fused polycyclic compound pigments such as flavanone yellow, dibromoanthrone orange, perillene red, quinacridone red, or dioxazine violet.

Examples of colorants also include various pigments such as chrome yellow, Hansa yellow, benzidine yellow, indanthrene yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, lake red (Watchyoung red), permanent red, Dupont oil red, Lixon red, rhodamine B lake, lake red C, rose bengal, aniline blue, ultramarine blue, chalco-oil blue, chlorinated methylene blue, phthalocyanine blue, phthalocyanine green, malachite green oxalate or coupled brown; and various dyes such as acridine dyes, xanthene dyes, azo dyes, benzoquinone dyes, azine dyes, anthraquinone dyes, dioxazine dyes, Thiazine dyes, azomethine dyes, indigo dyes, thioindigo dyes, phthalocyanine dyes, nigrosine dyes, polymethine dyes, triphenylmethane dyes, diphenylmethane dyes, thiazole dyes, or xanthene dyes. Black pigments or dyes such as carbon black may be mixed with these colorants as long as the transparency of the toner color is not impaired. In addition, examples of colorants also include disperse dyes, oil-soluble dyes, and the like.

The content of the colorant in the electrophotographic toner of the present invention is preferably about 1 to 30 parts by mass relative to about 100 parts by mass of the binder resin, more preferably within the above range so as not to impair the smoothness of the image surface after fixing. The range is as large as possible. When the content of the colorant is increased, in the case of forming an image with the same density, the thickness of the image can be made thinner to effectively prevent ink smearing. By appropriately selecting the kind of colorant, toners of various colors such as yellow toner, magenta toner, cyan toner and black toner can be obtained.

anti-sticking agent

Examples of general release agents include low-molecular-weight polyethylene, low-molecular-weight polypropylene, Fischer-Tropsh wax, montan wax, carnauba wax, rice bran wax, and candelilla wax.

charge control agent

A charge control agent may be added to the toner of the present invention if necessary. Conventionally known charge control agents can be used as the charge control agent in the present invention, and examples thereof include cetylpyridinium chloride, quaternary ammonium salts such as P-51 or P-53 (trade name, manufactured by Orient Chemical Industries, Ltd. . produced), azo metal complexes such as S-44 or S-34 (trade name, produced by Orient Chemical Industries, Ltd.), salicylic acid metal complexes such as E-84 (trade name, produced by Orient Chemical Industries, Ltd. Ltd.); a charge control agent comprising a resin having a polar group, a dye composed of a complex such as an aluminum complex, an iron complex, or a chromium complex; triphenylmethane-based pigments; metal oxides Material particles and metal oxide particles surface-treated with various silane coupling agents. When the toner is produced according to the wet method, it is preferable to use a material that is difficult to dissolve in water in view of controlling ionic strength and reducing waste water pollution.

The toner of the present invention may be a magnetic toner containing a magnetic material or a non-magnetic toner not containing a magnetic material.

The toner used in the present invention can be produced by using a Henshel mixer or a V-blender to mix toner particles and external additives described hereinafter. Furthermore, when toner particles are produced according to a wet method, external additives may be added during the wet method.

Examples of lubricating particles added (externally added) to the toner used in the present invention include: solid lubricants such as graphite, molybdenum disulfide, talc, aliphatic acids or metal salts of aliphatic acids; Olefins such as polypropylene, polyethylene or polybutene; heat-softening silicone compounds; fatty amides such as oleamide, erucamide, ricinamide or stearamide; vegetable waxes such as carnauba wax, rice bran wax, Candelilla wax, crude Japanese wax, or jojoba oil; animal waxes, such as beeswax; mineral and petroleum type waxes, such as montan, ozocerite, ceresine, paraffin, microcrystalline, or yuef - Waxes obtained by Fischer-Tropsch synthesis; and their modified products. These can be used alone or in combination. The average particle size of the lubricating particles is about 0.1 μm to 10 μm, and the lubricating particles having any of the above-mentioned exemplified chemical structures can be pulverized and adjusted to have an average particle size in the above-mentioned range. The amount of the lubricating particles added to the toner is preferably about 0.05% by mass to 2.0% by mass, more preferably about 0.1% by mass to 1.5% by mass, based on the amount of the toner.

In order to remove materials accumulated and deteriorated on the surface of the electrophotographic photoreceptor, inorganic particles, organic particles, composite particles obtained by attaching inorganic particles to organic particles, or the like may be added to the toner used in the present invention. Among them, inorganic particles excellent in polishing performance are particularly preferable. Examples of the inorganic particles include various inorganic oxides such as silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, Antimony oxide, tungsten oxide, tin oxide, tellurium oxide, manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride or boron nitride; nitrides and borides can preferably be used.

The above inorganic particles can be treated with a titanium coupling agent, such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearyl titanate, isopropyl tridecylbenzenesulfonyl titanate , bis(dioctyl pyrophosphate)oxyacetate titanate; or silane coupling agents such as γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)ammonia Propylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β-(N-vinylbenzylaminoethyl)γ-aminopropyltrimethoxysilane Hydrochloride, Hexamethyldisilazane, Methyltrimethoxysilane, Butyltrimethoxysilane, Isobutyltrimethoxysilane, Hexyltrimethoxysilane, Octyltrimethoxysilane, Decyltrimethoxysilane oxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane or p-methylphenyltrimethoxysilane.

In addition, higher fatty acid metal salts such as silicone oil, aluminum stearate, zinc stearate, or calcium stearate are preferably used to impart hydrophobicity.

Examples of the organic particles include styrene resin particles, styrene-acrylic resin particles, polyester resin particles, and polyurethane resin particles.

When the diameter of the particles is too small, the particles lack polishing ability, and when the particle diameter is too large, scratches tend to occur on the surface of the electrophotographic photoreceptor. Therefore, particles having an average particle diameter of about 5 nm to 1000 nm, preferably about 5 nm to 800 nm, more preferably about 5 nm to 700 nm are used. In addition, it is preferable that the sum of the amount of these particles and the added amount of the above-mentioned lubricating particles is about 0.6% by mass or more.

As other inorganic oxides added to the toner, it is preferable to add a small particle-sized inorganic oxide having a primary particle diameter of about 40 nm or less in order to improve powder fluidity, charge control, and the like. In addition, it is preferable to add an inorganic oxide having a particle diameter larger than that of the small-particle-diameter inorganic oxide in order to reduce adhesion and perform charge control. Heretofore known inorganic oxide particles can be used as "other inorganic oxides". Among them, in order to exert precise charge control, it is preferable to use silicon dioxide and titanium oxide in combination. Furthermore, for small-diameter inorganic particles, when a surface treatment is applied thereto, the dispersibility thereof can be enhanced, and as a result, the effect of improving powder fluidity is increased.

other components

The surface of the electrophotographic toner of the present invention may be covered with a surface layer. It is preferable that the surface layer does not significantly affect the mechanical properties and melt viscoelasticity of the toner. For example, when a non-melting surface layer or a surface layer having a high melting point thickly covers the toner, even in the case of using a crystalline polyester resin, it cannot sufficiently exhibit the To the low temperature fixing performance. Therefore, the film thickness of the surface layer is preferably as thin as possible, specifically, preferably about 0.001 μm to 0.5 μm.

In order to form such a thin surface layer having a thickness within the above range, for toner particles containing a binder resin and a colorant and may further contain inorganic particles and other materials as necessary, it is preferable that the surface of the toner particles is chemically treated. deal with. Examples of components constituting the thin surface layer include silane coupling agents, isocyanates, and vinyl monomers, and these components are chemically bonded to substances present on the surface of the toner particles. From the viewpoint of increasing the adhesive strength between the toner and a transfer-receiving material such as paper, these components preferably have polar groups introduced.

As the polar group, any polar group can be used as long as it is a functional group having polarity, examples of which include carboxyl group, carbonyl group, epoxy group, ether group, hydroxyl group, amino group, imino group, cyano group, acyl group Amino, imido, ester and sulfonic acid groups. Examples of methods of chemical treatment include oxidation using a strong oxidizing substance such as peroxide, an oxidation method such as ozone oxidation, or plasma oxidation, and a method of bonding a polymerizable monomer having a polar group by graft polymerization. By chemically treating the particle surface, the polar group can be firmly bonded to the molecular chain of the binder resin through a covalent bond.

In the present invention, the charged material can be further chemically or physically attached to the surface of the toner particles. In addition, metal particles, metal oxide particles, metal salt particles, ceramic particles, resin particles or carbon black particles may be added externally to improve the chargeability, conductivity, powder fluidity or lubricity of the toner.

The volume average particle diameter of the electrophotographic toner of the present invention is preferably about 1 μm to 20 μm, more preferably about 2 μm to 8 μm. The number average particle diameter of the electrophotographic toner of the present invention is preferably about 1 μm to 20 μm, more preferably about 2 μm to 8 μm. The volume average particle diameter and the number average particle diameter can be measured using, for example, a Coulter counter (trade name: Type TA-II, manufactured by Beckman Coulter Co., Ltd.) with an aperture diameter of 50 μm. At this time, the measurement is performed after the toner is dispersed in an aqueous electrolyte solution (ISOTON-II aqueous solution) and further dispersed by applying ultrasonic waves for 30 seconds or more.

The method of producing the electrophotographic toner of the present invention described above is not particularly limited, but the method of producing the electrophotographic toner of the present invention described below is particularly preferably used. Since the electrophotographic toner of the present invention has the above constitution, the toner is excellent in toner blocking resistance, image storability, and low-temperature fixing performance. When a specific polyester resin (crystalline polyester resin) is used and the polyester resin has a crosslinked structure brought about by unsaturated bonds, the electrophotographic toner has a wide fixation width to provide excellent anti-smudge property , and it is possible to satisfactorily prevent toner from excessively bleeding into recording media such as paper. In addition, when the particle shape of the toner is made spherical, transfer efficiency can be improved.

two-component developer

The electrophotographic toner of the present invention thus obtained can be used as a one-component developer as it is, or as the toner in the two-component developer of the present invention consisting of a carrier and a toner. Hereinafter, the two-component developer of the present invention will be explained.

The carrier that can be used in the two-component developer is not particularly limited, and conventionally known carriers can be used. For example, a resin-coated carrier having a resin coating on the surface of a core can be used. In addition, a resin-dispersed carrier in which a conductive material is dispersed in a matrix resin may be used.

Examples of resins used for the resin coating layer and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone , vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid copolymer, pure siloxane resin composed of organic siloxane bonds or its modified material, fluorinated resin, polyester, polycarbonate, phenolic resin and epoxy resin, but the resin is not limited thereto.

Examples of conductive materials include metals such as gold, silver, or copper; carbon black, titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, and tin oxide, but are not limited thereto.

Examples of carrier core materials include magnetic metals such as iron, nickel or cobalt; magnetic oxides such as ferrite or magnetite; and glass beads. When the carrier is used in a magnetic brush method, a magnetic material is preferably used as the core material. The volume average particle diameter of the carrier core material is generally about 10 μm to 500 μm, preferably about 30 μm to 100 μm.

Examples of the method of coating the resin on the surface of the core material include a method of dissolving the coating resin and various additives used as necessary in a suitable solvent to form a coating layer forming solution, and then coating the solution. The solvent is not particularly limited, and may be appropriately selected in consideration of the coating resin to be used, coating performance, and the like.

Examples of specific resin coating methods include: a dipping method in which a carrier core is immersed in a solution for coating formation, a spraying method in which a solution for coating layer formation is sprayed on the surface of a carrier core, a method of floating a carrier core with fluidized air A fluidized bed method of spraying a solution for forming a coating layer in a state, and a kneader coater method of mixing a carrier core material and a solution for forming a coating layer in a kneader coater followed by removing the solvent.

The mixing ratio (mass ratio) of the electrophotographic toner of the present invention to the carrier (toner:carrier) in the two-component developer can be appropriately set; however, it is usually about 1:100 to 30:100, Preferably it is about 3:100 to 20:100.

image forming method

Next, the image forming method of the present invention using the electrophotographic toner of the present invention or the electrophotographic developer of the present invention will be described. The image forming method includes: forming an electrostatic latent image on a surface of a latent image holder; developing the electrostatic latent image formed on the surface of the latent image holder using a developer carried on a developer carrier to form a toner image; transferring the toner image formed on the surface of the latent image holder onto a surface of a transfer-receiving material such as paper; and thermally fixing the toner image transferred onto the surface of the transfer-receiving material, wherein , as the developer, the electrophotographic toner of the present invention or the electrophotographic developer of the present invention is used.

The developer may be a one-component developer or a two-component developer. In the case of using a one-component developer, the electrophotographic toner of the present invention can be used as it is, and in the case of using a two-component developer, the two-component developer of the present invention can be used. The electrophotographic toner of the present invention and the carrier are mixed in the component developer. In any of the above steps, known steps in image forming methods may be employed.

As the latent image holder, for example, an electrophotographic photoreceptor and a dielectric recording medium can be used. In the case of using an electrophotographic photoreceptor, the surface of the electrophotographic photoreceptor is uniformly charged using a corona charger, a contact charger, or the like, and then exposed to form an electrostatic latent image (latent image forming process). Then, the electrophotographic photoreceptor is brought into contact with or close to a developing roller on whose surface a developer layer is formed, so that the toner particles are attached to the electrostatic latent image, thereby forming a toner image on the electrophotographic photoreceptor (developing process). The formed toner image is transferred onto the surface of a transfer-receiving material such as paper or the like using a corona charger or the like (transfer process). Also, the toner image transferred onto the surface of the transfer-receiving material is thermally fixed using a fixing device to form a final toner image. At the time of thermal fixing using a fixing device, in order to prevent staining or the like from occurring, a release agent is generally supplied to a fixing member in the fixing device.

In the electrophotographic toner of the present invention (here and hereinafter including the electrophotographic toner contained in the two-component developer of the present invention), when a crosslinked structure exists in the binder resin, since As it does, the binder resin is excellent in release performance; therefore, fixing can be performed with a reduced amount of a release agent or without the use of a release agent.

From the viewpoint of preventing oil from adhering to the transfer-receiving material and the fixed image, it is preferable not to use a release agent. However, in the case where the amount of the release agent to be supplied is set to 0 mg/cm ² , the fixing member comes into contact with the transfer-receiving material such as paper or the like when fixing, sometimes increasing the amount of wear of the fixing member , and degrades the durability of the fixing unit. ^Therefore , from a practical point of view, it is preferable to supply the release agent in a small amount of about 8.0×10 ⁻³ mg/cm ² or ^less to the fixing member.

When the amount of the release agent supplied exceeds 8.0×10 ⁻³ mg/cm ² , the image quality deteriorates because the release agent adheres to the surface of the fixed image. In particular, this phenomenon may be clearly visible when transmitted light is used, for example in OHP (Overhead Projector). In addition, the adhesion of the release agent to the transfer-receiving material may become conspicuous in some cases, which may cause stickiness. Furthermore, the larger the amount of the release agent to be supplied, the larger the size of the tank storing the release agent must be, resulting in an increase in the size of the fixing device itself.

The release agent is not particularly limited, and examples thereof include liquid release agents such as simethicone oil, fluorinated oil, fluorosilicone oil, and modified oils such as amino-modified silicone oil. Among them, in view of adhering to the surface of the fixing member and forming a uniform release layer, modified oils such as amino-modified silicone oils are preferable because of their excellent wettability to the fixing member.

In addition, fluorinated oils and fluorosilicone oils are preferable in view of the performance of forming a uniform release layer.

In view of cost, it is impractical to use fluorinated oil or fluorosilicone oil in conventionally known image forming methods that do not use the electrophotographic toner of the present invention because the amount of the release agent to be supplied cannot be reduced in those methods . However, in consideration of cost, there is no practical problem in using fluorinated oil or fluorosilicone oil in the case of using the electrophotographic toner of the present invention, because the amount of the release agent to be supplied can be significantly reduced in this case.

The method of supplying the release agent on the surface of a roller or a belt used as a fixing member and used for heat pressing is not particularly limited. Examples of the method include a pad method using a pad in which a release agent is impregnated, a web method, a roll method, a non-contact spray method (spray method), and the like. Among them, the web method and the roll method are preferable.

When these methods are used, there are advantages in that the release agent can be supplied uniformly and the supply amount can be easily controlled. In order to uniformly supply the release agent over the entire fixing member by the spray method, it is necessary to use a doctor blade or the like separately.

The amount of release agent supplied can be measured as follows. That is, when plain paper (a typical example is copy paper with a trade name of J PAPER, which is produced by Fuji Xerox Co., Ltd.) for general copiers passes through a fixing member supplied with a release agent on its surface, the release agent adheres to The plain paper. Use a Soxhlet extractor to extract the adhered detackifier. Here, hexane was used as a solvent. The amount of the release agent contained in the hexane was quantitatively measured with an atomic absorption analyzer, whereby the amount of the release agent adhered to plain paper could be quantitatively measured. This amount is defined as the supply amount of the release agent supplied to the fixing member.

Examples of the transfer-receiving material (recording material) on which the toner image is transferred include, for example, plain paper and OHP sheets used in electrophotographic copiers, electrophotographic printers, and the like. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer-receiving material is also as smooth as possible. For example, coated paper in which the surface of plain paper is coated with a resin or the like, art paper for printing, or the like can be preferably used.

When the image forming method using the electrophotographic toner of the present invention is used, aggregation of the toner does not occur. Therefore, an image with excellent image quality can be formed, low-temperature fixing is possible, and image storability is excellent. In addition, when the binder resin has a crosslinked structure, adhesion of the release agent to the transfer-receiving material hardly occurs. As a result, when an image is formed using a transfer-receiving material such as a seal and a tape whose backside is given an adhesiveness, an image with high image quality and high density can be formed on a seal, a self-adhesive label, or the like.

Production method of electrophotographic toner

As a production method of the electrophotographic toner of the present invention, a kneading pulverization method and a wet granulation method can be used; however, a wet granulation method is more desirable. As the wet granulation method, known methods such as melt-suspension method, emulsion coagulation method, and dissolution-suspension method can be preferably used. As the production method of the electrophotographic toner of the present invention, an emulsion aggregation method is preferable in view of easy control of the particle diameter and shape of the toner. Hereinafter, the emulsion coagulation method will be described as an example. The emulsion coagulation method includes: a dispersion (or emulsification) step in which a binder resin is dispersed (or emulsification) to form dispersed particles (or emulsified particles (droplets)); an aggregation step in which a binder resin containing the Agglomerates of the dispersed particles (or emulsified particles (droplets)); and a fusing step, in which the agglomerates are thermally fused.

As an example of producing an electrophotographic toner comprising a binder resin and a colorant by using an emulsion aggregation method, the following method can be used: mixing a dispersion of binder resin particles (including emulsion) and a dispersion of colorant particles, The binder resin particles and the colorant particles are thereby aggregated, followed by heating to a temperature equal to or higher than the glass transition temperature or melting point of the binder resin to fuse the binder resin particles and the colorant particles. When dispersing or emulsifying the particle dispersion (including emulsified solution) of the binder resin, a colorant may also be contained. If a coloring agent is included in the dispersion (emulsification) (hereinafter simply referred to as dispersion), the polymer and coloring can be carried out by mixing the coloring agent or an organic solvent dispersion of the coloring agent into the organic solvent solution of the polymer. Mixture of agents.

Hereinafter, the case of separately preparing a particle dispersion of a binder resin (which includes an emulsified solution; hereinafter collectively referred to as "particle dispersion") and a particle dispersion of a colorant will be described.

Preparation of Polyester Resin Particle Dispersion

The particle dispersion of the polyester resin can be formed by applying a shear force to a liquid in which an aqueous medium and a sulfonated polyester resin are mixed.

At that time, when the polyester resin is heated or dissolved in an organic solvent, the viscosity of the polymer solution can be reduced, whereby emulsified particles can be formed. Furthermore, in order to stabilize the emulsified particles and increase the viscosity of the aqueous medium, a dispersant may be used.

Examples of dispersants include: water-soluble polymers such as polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium polyacrylate or sodium polymethacrylate; surface active agents such as anionic surfactants such as sodium dodecylbenzenesulfonate, sodium stearyl sulfate, sodium oleate, sodium laurate or potassium stearate; cationic surfactants such as laurylamine acetate, hard Tallamine acetate or lauryltrimethylammonium chloride; amphoteric surfactants such as lauryldimethylamine oxide; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylbenzenes base ethers or polyoxyethylene alkylamines; inorganic compounds such as tripotassium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate or barium carbonate.

In the case of using an inorganic compound as a dispersant, a commercially available inorganic compound can be used as it is. Alternatively, to obtain particles, a method of producing particles of an inorganic compound in a dispersant may be employed. The amount of the dispersant used is preferably about 0.01 to 20 parts by mass based on 100 parts by mass of the polyester resin (binder resin).

During the above dispersion, when a dicarboxylic acid having a sulfonic acid group is copolymerized in the polyester resin (that is, when an appropriate amount of a component derived from a dicarboxylic acid having a sulfonic acid group is contained in the acid-derived component ), can reduce the addition amount of dispersion liquid stabilizer such as surfactant, or can omit the addition of dispersion liquid stabilizer.

Examples of the organic solvent include ethyl acetate and toluene, and the kind of the organic solvent can be appropriately selected according to the properties of the polyester resin.

Based on the total amount of 100 parts by mass of polyester resin and other monomers added as needed (hereinafter, polyester resin and other monomers added as needed are sometimes referred to simply as "polymer"), the amount of organic solvent used Preferably it is about 50-5000 mass parts, More preferably, it is about 120-1000 mass parts. Before forming emulsified particles, a coloring agent may be mixed therein. The colorant used is the colorant described above in the paragraph "Colorant" in the specification of the present invention.

Examples of dispersing (or emulsifying) machines for forming emulsified particles include homogenizers, homomixers, press kneaders, extruders, and media dispersers. Regarding the size of dispersed particles (droplets) of polyester resin, the average particle diameter (volume average particle diameter) thereof is preferably about 0.01 μm to 1 μm, more preferably about 0.03 μm to 0.4 μm, still more preferably about 0.03 μm to 0.3 μm.

Preparation of Colorant Particle Dispersion

The dispersion method of the colorant is not particularly limited, and examples thereof include arbitrary methods such as general dispersion using devices such as a rotary shear homogenizer and a mill (such as a ball mill with a medium, a sand mill, or a bead mill (dynomill)) method. According to necessity, a surfactant may be used to prepare an aqueous dispersion of the colorant, or a dispersant may be used to prepare an organic solvent dispersion of the colorant. As the surfactant or dispersant used for dispersion, a dispersant similar to that which can be used for dispersing the polyester resin can be used.

The amount of the coloring agent added is preferably about 1% by mass to 20% by mass, more preferably about 1% by mass to 10% by mass, still more preferably about 2% by mass to 10% by mass, relative to the total amount of the polymer, Particularly preferably about 2% by mass to 7% by mass. If a colorant is added at the time of emulsification, the polymer can be mixed with the colorant by mixing the colorant or an organic solvent dispersion of the colorant with an organic solvent solution of the polymer.

Agglutination

At the time of aggregation, the binder resin particle dispersion and the colorant particle dispersion are mixed, and the mixture is preferably heated at a temperature close to the melting point of the polyester resin contained as the binder resin and equal to or lower than the melting point. Heat is applied to form agglomerates. When the pH of the dispersion is made acidic with stirring, aggregates are generated. The pH value is preferably about 2-6, more preferably about 2.5-5, even more preferably about 2.5-4. At this time, a coagulant can be effectively used.

As the coagulant to be used, in addition to a surfactant having a polarity opposite to that of the surfactant used as the dispersant and an inorganic metal salt, a complex of a divalent or higher than divalent metal can be preferably used. things. The case where the metal complex is used is particularly preferable because the amount of the surfactant used can be reduced and charging characteristics can be improved.

Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride or aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide or calcium polysulfide; etc. Among them, specifically, aluminum salts and polymers thereof are preferably used. In order to obtain a sharper (narrower) particle size distribution, in terms of the valence state of the inorganic metal salt, divalent is more preferred than monovalent, trivalent is more preferred than divalent, and tetravalent is more preferred than trivalent. Furthermore, among inorganic metal salts having the same valence state, polymeric inorganic metal salts are more preferable.

fusion

In fusion, the pH of the aggregate suspension is controlled to be about 3 to 7 under stirring similar to that in agglutination to stop aggregation, followed by heating to a temperature equal to or higher than the melting point of polyester resin to fuse the agglutination thing. As long as the heating temperature is equal to or higher than the melting point of the polyester resin, there is no problem regarding the heating temperature. The heating is continued for a period of time sufficient for sufficient fusion to occur, ie, for a period of about 0.5 hours to 10 hours.

The fused particles resulting from the fusion are subjected to a solid-liquid separation process such as filtration, and, if necessary, subjected to a washing process and a drying process to become toner particles. In this case, in order to ensure sufficient charging characteristics and reliability for the toner, it is preferable to sufficiently perform cleaning in the cleaning step. In the drying process, any method such as an ordinary vibration type fluidized drying method, a spray drying method, a freeze drying method or a flash spray method may be employed. The toner particles are preferably adjusted so that the water content after drying is about 1.0% by mass or less, more preferably about 0.5% by mass or less.

In the fusing step, a crosslinking reaction may proceed while the polyester resin is heated at a temperature equal to or higher than the melting point of the polyester resin or after fusing is completed. The crosslinking reaction can also be carried out simultaneously with the agglutination. In the case of performing a crosslinking reaction, for example, an unsaturated sulfonated crystalline polyester resin copolymerized with a double bond component is used as the binder resin, and the resin is subjected to a radical reaction to introduce a crosslinked structure . At this time, the polymerization initiators shown below can be used.

Examples of the polymerization initiator include tert-butyl peroxy-2-ethylhexanoate, cumyl peroxypivalate, tert-butyl peroxylaurate, benzoyl peroxide, lauroyl peroxide, Octanoyl peroxide, di-tert-butyl peroxide, tert-butyl cumene peroxide, dicumyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2- Methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) ), 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 1,4- Bis(tert-butylperoxycarbonyl)cyclohexane, 2,2-bis(tert-butylperoxy)octane, n-butyl-4,4-bis(tert-butylperoxy)valerate, 2,2-bis(tert-butylperoxy)butane, 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(tert-butyl peroxy)hexane, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, di-tert-butyl diperoxyisophthalate, 2,2- Bis(4,4-di-tert-butylperoxycyclohexyl)propane, di-tert-butylperoxy-α-methyl succinate, di-tert-butylperoxydimethyl glutarate, di-tert-butyl Hexahydroterephthalate peroxide, di-tert-butylperoxyzelate, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, diethylene glycol -Bis(tert-butylperoxycarbonate), di-tert-butylperoxytrimethyl adipate, tris(tert-butylperoxy)triazine, vinyltris(tert-butylperoxy)silane , 2,2'-Azobis(2-methylpropionamide dihydrochloride), 2,2'-Azobis[N-(2-carboxyethyl)-2-methylpropionamide] and 4,4'-azobis(4-cyanovaleric acid).

These polymerization initiators may be used alone or in combination of two or more. The type and amount of the polymerization initiator are selected according to the amount of unsaturated moiety in the polymer and the type and amount of the colorant to coexist. The polymerization initiator may be mixed with the polymer before dispersion, or may be incorporated into the aggregate at the time of aggregation. Furthermore, it can be introduced at the time of fusion or after fusion. In the case of introduction at the time of aggregation, at the time of fusion, or after fusion, a liquid obtained by dissolving or dispersing a polymerization initiator therein is added to a particle dispersion (for example, a resin particle dispersion). The polymerization initiator may contain known additives, such as a crosslinking agent, a chain transfer agent, or a polymerization inhibitor, for controlling the degree of polymerization.

Hereinafter, particularly preferred modes of the present invention are listed. However, the present invention is not limited to these modes.

[1] A binder resin comprising about 1 ppm to 10000 ppm of a rare earth element.

[2] The binder resin described in the preferred aspect [1], comprising a polyester resin containing about 1 ppm to 10000 ppm of a rare earth element.

[3] The binder resin according to the preferred aspect [1], wherein the rare earth element is Sc, Y, Yb or Sm.

[4] The binder resin of the preferred mode [1], wherein the binder resin is synthesized using a catalyst represented by the following general formula (1):

General formula (1)X(OSO ₂ CF ₃ ) ₃ ,

In the general formula (1), X represents Sc, Y, Yb or Sm.

[5] The binder resin of the preferred mode [1], wherein the binder resin is synthesized using a catalyst represented by the following general formula (2):

General formula (2)X(N(SO ₂ CF ₃ ) ₂ ) ₃

In the general formula (2), X represents Sc, Y, Yb or Sm.

[6] An electrophotographic toner comprising a binder resin and a colorant, wherein the binder resin is any one of the binder resins described in the preferred aspects [1] to [5].

[7] A method for producing an electrophotographic toner, the method comprising:

emulsifying a binder resin to prepare emulsified particles of the binder resin;

agglomerating to form an aggregate comprising emulsified particles of the binder resin; and

fuse the agglutinates,

Wherein, the binder resin is any one of the binder resins described in the preferred forms [1] to [5].

[8] An electrophotographic developer comprising an electrophotographic toner and a carrier, wherein the electrophotographic toner is the electrophotographic toner described in the preferred aspect [6].

[9] An image forming method comprising:

forming an electrostatic latent image on the surface of the latent image holder;

developing the electrostatic latent image formed on the surface of the latent image holder using a developer carried on the developer carrier to form a toner image;

transferring the toner image formed on the surface of the latent image holder to the surface of the transfer-receiving material; and

heat-fixing the transferred toner image on the surface of the transfer-receiving material,

Wherein, the developer is the electrophotographic toner described in the preferred mode [6] or the electrophotographic developer described in the preferred mode [8].

[10] An electrophotographic toner comprising a binder resin and a colorant, wherein the binder resin comprises a polyester resin synthesized by a heterogeneous catalyst in which rare earth metal trifluoro Methanesulfonate or rare earth metal trifluoromethanesulfonimide salt is loaded on the carrier.

[11] A polyester resin for electrophotographic toner, which is synthesized from acid units having dicarboxylic acid groups and alcohol units having diol groups, wherein the polyester The resin is synthesized by adopting a heterogeneous catalyst, and in the heterogeneous catalyst, a rare earth metal trifluoromethanesulfonate or a rare earth metal trifluoromethanesulfonyl imide is supported on a carrier.

[12] The polyester resin for electrophotographic toner described in the preferred aspect [11], wherein the polyester resin is crystalline.

[13] The polyester resin for electrophotographic toner described in the preferred mode [11], wherein the rare earth metal triflate is composed of X(OSO ₂ CF ₃ ) ₃ (wherein X represents a rare earth element )express.

[14] The polyester resin for electrophotographic toner described in the preferred aspect [11], wherein the rare earth metal trifluoromethanesulfonimide salt is composed of X(N(SO ₂ CF ₃ ) ₂ ) ₃ (where X represents a rare earth element).

[15] A method of producing a polyester resin for electrophotographic toner, the method comprising synthesizing the polyester resin from acid units having dicarboxylic acid groups and alcohol units having diol groups, wherein the In the above synthesis, a heterogeneous catalyst is used as a synthesis catalyst. In the heterogeneous catalyst, a rare earth metal trifluoromethanesulfonate or a rare earth metal trifluoromethanesulfonyl imide is supported on a carrier.

[16] The method for producing a polyester resin for electrophotographic toner described in the preferred mode [15], further comprising: after the synthesis, dissolving the polyester resin in a solvent for dissolving the polyester resin The polyester resin is dissolved, and the heterogeneous catalyst in which a rare earth metal trifluoromethanesulfonate or a rare earth metal trifluoromethanesulfonimide salt is supported on a carrier is recovered from the obtained solution.

[17] A method of producing an electrophotographic toner, the method comprising:

mixing the binder resin particle dispersion and the colorant particle dispersion to aggregate the binder resin particles and colorant particles; and

heating the aggregated particles to a temperature equal to or higher than the glass transition temperature or melting point of the binder resin to fuse the aggregated particles,

Wherein, the binder resin comprises a polyester resin for electrophotographic toner, and the polyester resin is synthesized by using a heterogeneous catalyst, and in the heterogeneous catalyst, a rare earth metal triflate or a rare earth metal The trifluoromethanesulfonimide salt is supported on the carrier.

[18] An electrophotographic developer comprising a carrier and a toner for an electrophotographic toner, wherein the toner comprises at least a binder resin and a colorant, and the binder resin comprises The polyester resin synthesized by the catalyst, in the heterogeneous catalyst, the rare earth metal trifluoromethanesulfonate or the rare earth metal trifluoromethanesulfonimide salt is supported on the carrier.

[19] An image forming method, the method comprising:

forming an electrostatic latent image on the surface of the latent image holder;

developing the electrostatic latent image formed on the surface of the latent image holder using a developer carried on the developer carrier to form a toner image;

transferring the toner image formed on the surface of the latent image holder to the surface of the transfer-receiving material; and

heat-fixing the transferred toner image on the surface of the transfer-receiving material,

Wherein, the developer includes a carrier and a toner; the toner includes at least a binder resin and a colorant; the binder resin includes a polyester resin synthesized by a heterogeneous catalyst, in which , rare earth metal trifluoromethanesulfonate or rare earth metal trifluoromethanesulfonimide salt loaded on the support.

Example

Hereinafter, embodiments of the present invention will be explained. However, the present invention is not limited to these Examples. Hereinafter, "part" means "part by mass", and "%" means "% by mass". The average particle diameter of the toner particles is measured using a Coulter counter (trade name: Model TA-II, manufactured by Beckman Coulter Co., Ltd.). The average particle diameters of the resin particles, colorant and release agent were measured using a laser diffraction type particle size distribution analyzer (trade name: LA-700, manufactured by Horiba).

The weight average molecular weight (Mw) of the resin in the resin particles and toner particles was measured with a gel permeation chromatography apparatus (trade name: HLC-8120GPC, manufactured by Tosoh Corporation).

Fluorescence intensity of the toner is obtained by measuring rare earth elements (scandium and yttrium) using fluorescent X-rays. The amount of the rare earth element contained in the toner is calculated from a calibration curve separately prepared.

Chargeability was evaluated according to the method described below. To the electrophotographic toner was added and mixed: 0.8% by mass of silica particles (hydrophobic silica, trade name: RX50, manufactured by Nippon Aerosil Co. , Ltd.) and 1.0% by mass of metatitanate particles (obtained by treating 100 parts by mass of metatitanic acid and 50 parts by mass of isobutyltrimethoxysilane), the particles being metatitanic acid and isobutyltrimethoxy An electrophotographic toner for external addition was prepared as a reaction product of a base silane and had a primary average particle diameter of 20 nm. 8 parts by mass of electrophotographic toner for external addition and 92 parts by mass of a carrier coated with methyl methacrylate resin were introduced into the V-shaped mixer, and stirred for 20 minutes, then loaded into a full-color copier (trade name: A COLOR 935, manufactured by Fuji Xerox Co., Ltd.), after assembly, was measured with a blow-off charge amount measuring device (manufactured by Toshiba Corp.) (using a 20 μm mesh). When the charge amount was about 10 to 40 μC/g, it was judged as acceptable, and when it was out of this range, it was judged as unacceptable.

The charge amount was measured under two conditions of 30° C. and RH 80% (relative humidity 80%) (A-zone), 10° C. and RH 15% (C-zone).

Example 1-1

Synthetic Crystalline Polyester Resin 1-(1)

In a flask mix 200 parts of 1,9-nonanediol, 260 parts of 1,12-dodecanedicarboxylic acid, 7.4 parts of dimethyl 5-sulfoisophthalate, 21 parts of 5-tert-butylisophthalic acid Diformic acid and 12.6 parts of scandium trifluoromethanesulfonate as a catalyst were subjected to nitrogen substitution, and the temperature was raised to 100° C. to dissolve these substances. The temperature was maintained at 100°C and the flask was depressurized to 20 mm Hg pressure over 1 hour with stirring. Further, the pressure was further lowered to 10 mmHg or less, followed by continuing the reaction in this state for 7 hours, whereby a resin was obtained. The weight average molecular weight (Mw) was 20000.

Production of electrophotographic toner 1-(1)

由Junke and Kunkel IKALabortechnic生产)中，在95℃搅拌10质量份得到的结晶性聚酯树脂1-(1)和90质量份蒸馏水，并以10000rpm(转/分钟)离心3分钟进行乳化，从而得到乳液。向100质量份该乳液加入4质量份铜酞菁颜料(C.I.(染料索引)颜料蓝15:3)分散液(固体含量为0.4质量份)，并在搅拌下缓慢加入10g 1质量％硫酸铝水溶液以进行凝集。在60℃搅拌溶液2小时后，控制其pH为4.5，随后逐渐加热，并在95℃加热并进行搅拌20分钟。此后，在空气中冷却溶液，并用离子交换水清洗，随后冷冻干燥，从而制得电子照相调色剂1-(1)。In the emulsification device (trade name: ULTRA-

Produced by Junke and Kunkel IKA Labortechnic), 10 parts by mass of the obtained crystalline polyester resin 1-(1) and 90 parts by mass of distilled water were stirred at 95° C., and centrifuged at 10000 rpm (rotation/minute) for 3 minutes to emulsify, thereby obtaining lotion. To 100 parts by mass of this emulsion, add 4 parts by mass of copper phthalocyanine pigment (CI (Dye Index) Pigment Blue 15:3) dispersion (solid content: 0.4 parts by mass), and slowly add 10 g of 1 mass % aluminum sulfate aqueous solution under stirring for agglutination. After the solution was stirred at 60°C for 2 hours, its pH was controlled to 4.5, and then gradually heated, and heated at 95°C with stirring for 20 minutes. Thereafter, the solution was cooled in air, washed with ion-exchanged water, and then freeze-dried to prepare Electrophotographic Toner 1-(1).

The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain the average particle diameter is 5.8 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Example 1-2

Synthetic Crystalline Polyester Resin 1-(2)

Crystalline polyester resin 1-(2) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the catalyst was changed to 0.126 parts of scandium trifluoromethanesulfonate , making the resin constitution similar to that of Example 1-1. Its weight average molecular weight (Mw) was 21000.

Production of electrophotographic toner 1-(2)

Electrophotographic toner 1-(2) was prepared in a similar manner to "Production of electrophotographic toner 1-(1)" in Example 1-1, except that the polyester resin was replaced by crystalline polyester Resin 1-(2).

The average particle diameter of the electrophotographic toner thus obtained was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain the average particle diameter The diameter is 5.7 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Example 1-3

Synthesis of Crystalline Polyester Resin 1-(3)

Crystalline polyester resin 1-(3) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the catalyst was changed to 5.6 parts scandium trifluoromethanesulfonate . Its weight average molecular weight (Mw) was 19,000.

Production of electrophotographic toner 1-(3)

Electrophotographic toner 1-(3) was prepared in a similar manner to "Production of electrophotographic toner 1-(1)" in Example 1-1, except that the polyester resin was replaced by crystalline polyester Resins 1-(3).

The average particle diameter of the electrophotographic toner thus obtained was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain the average particle diameter The diameter is 6.5 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Example 1-4

Synthesis of Crystalline Polyester Resin 1-(4)

Crystalline polyester resin 1-(4) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the resin composition was changed to 301 parts by mass of terephthalic acid Dimethyl ester and 248 parts by mass of 1,9-nonanediol, and the catalyst is changed to 12.6 parts of scandium trifluoromethanesulfonate. Its weight average molecular weight (Mw) was 19,000.

Production of electrophotographic toner 1-(4) (dissolution-suspension method)

由Junke and Kunkel IKA Labortechnic生产)通过在50℃以10000rpm搅拌3分钟使其悬浮，从而得到悬浮溶液。28 parts by mass of crystalline polyester resin 1-(4), 5 parts by mass of copper phthalocyanine pigment (CI Pigment Blue 15:3), and 60 parts by mass of toluene were dispersed with a sand mill to prepare a dispersion liquid. To 36 parts by mass of a 3.0% by mass aqueous solution of carboxymethylcellulose, 45 parts by mass of a 40% by mass calcium carbonate suspension solution and 45 parts by mass of water were added. Add the entire dispersion liquid to the resulting solution at 50°C, and then use an emulsifying device (trade name: ULTRA-

produced by Junke and Kunkel IKA Labortechnic) was suspended by stirring at 50° C. at 10000 rpm for 3 minutes to obtain a suspension solution.

Subsequently, under a nitrogen stream, toluene and water were evaporated as much as possible to obtain a dispersion of crosslinked particles. To the obtained cross-linked particle dispersion, add about 5 times the amount of water in the cross-linked particle dispersion, dissolve calcium carbonate with hydrochloric acid, wash with water repeatedly, and finally depressurize and freeze-dry to obtain an electrophotographic toner 1-(4).

The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 6.3 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Example 1-5

Synthesis of Crystalline Polyester Resin 1-(5)

Crystalline polyester resin 1-(5) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the catalyst was changed to 12.6 parts of trifluoromethanesulfonyl Amine scandium salt. Its weight average molecular weight (Mw) was 18,000.

Production of electrophotographic toner 1-(5)

Electrophotographic toner 1-(5) was prepared in a similar manner to "Production of electrophotographic toner 1-(1)" in Example 1-1, except that the polyester resin was replaced by crystalline polyester Resins 1-(5).

The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 6.5 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Examples 1-6

Synthetic Crystalline Polyester Resin 1-(6)

Crystalline polyester resin 1-(6) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the catalyst was changed to 12.6 parts of yttrium trifluoromethanesulfonate , making the resin constitution similar to that of Example 1-1. Its weight average molecular weight (Mw) was 19,000.

Production of electrophotographic toner 1-(6)

Electrophotographic toner 1-(6) was prepared in a similar manner to "Production of electrophotographic toner 1-(1)" in Example 1-1, except that the polyester resin was replaced by crystalline polyester Resins 1-(6).

The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 6.5 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Example 1-7

Synthesis of Crystalline Polyester Resin 1-(7)

Crystalline polyester resin 1-(7) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the resin composition was changed to 200 parts of 1,6-hexyl Diol, 260 parts of 1,9-nonanedicarboxylic acid and 7.4 parts of dimethyl 5-sulfoisophthalate. Its weight average molecular weight (Mw) was 19,000.

Production of electrophotographic toner 1-(7)

Electrophotographic toner 1-(7) was prepared in a similar manner to "Production of electrophotographic toner 1-(1)" in Example 1-1, except that the polyester resin was replaced by crystalline polyester Resins 1-(7).

The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 6.5 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Comparative example 1-1

Synthetic Crystalline Polyester Resin 1-(8)

Crystalline polyester resin 1-(8) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the catalyst was changed to 0.03 parts of scandium trifluoromethanesulfonate . Its weight average molecular weight (Mw) was 15,000.

Production of electrophotographic toner 1-(8)

Electrophotographic toner 1-(8) was prepared in a similar manner to "Production of electrophotographic toner 1-(1)" in Example 1-1, except that the polyester resin was replaced by crystalline polyester Resins 1-(8).

The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 5.7 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Comparative example 1-2

Synthesis of Crystalline Polyester Resin 1-(9)

Crystalline polyester resin 1-(9) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the catalyst was changed to 50 parts of scandium trifluoromethanesulfonate . Its weight average molecular weight (Mw) was 20,000.

Production of electrophotographic toner 1-(9)

Electrophotographic toner 1-(9) was prepared in a similar manner to "Production of electrophotographic toner 1-(1)" in Example 1-1, except that the polyester resin was replaced by crystalline polyester Resins 1-(9).

The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 5.8 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Comparative example 1-3

Synthetic Crystalline Polyester Resin 1-(10)

Crystalline polyester resin 1-(10) was prepared in a manner similar to the synthesis of crystalline polyester resin 1-(1) in Example 1-1, except that the catalyst was changed to 0.2 parts of tetra-n-butyl titanic acid ester. After nitrogen substitution, stirring was performed at a reaction temperature of 180° C. for 3 hours, followed by polymerization under reduced pressure for 5 hours. Thereafter, over 4 hours, the temperature was finally raised to 220° C., and the reaction was finally performed for a total of 12 hours to synthesize a resin. Its weight average molecular weight (Mw) was 25,000.

Production of electrophotographic toner 1-(10)

Electrophotographic toner 1-(10) was prepared in a similar manner to "Production of electrophotographic toner 1-(1)" in Example 1-1, except that the polyester resin was replaced by crystalline polyester Resin 1-(10).

The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 6.5 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Electrophotographic developers were evaluated as described below. That is, image formation was performed by externally adding electrophotographic toner and using a modified digital color copier (trade name: DOCUCENTRE COLOR 500CP, manufactured by Fuji Xerox Co., Ltd.), and the initial image (10th image) and Image quality stability (melting irregularities) and background contamination for each image of the 50,000th image.

Image quality and background contamination were evaluated according to the following evaluation criteria.

-A: There is no problem with the image.

-B: Although a little contamination was observed, there was no real problem.

-C: The image cannot be used practically because obvious contamination was observed.

In addition, comprehensive evaluation of the electrophotographic toner was performed according to the following evaluation criteria.

-A: no problem;

-B: Although a little contamination was observed, there was no real problem.

-C: The image cannot be used practically because obvious contamination was observed.

These assessments are summarized in Table 1.

Table 1

As is clear from Table 1, the electrophotographic toner of the present invention has weak environmental dependence in charge amount.

Example 2-1

Synthesis of Crystalline Polyester Resin 2-(1)

In a flask mix 200 parts of 1,9-nonanediol, 260 parts of 1,12-dodecanedicarboxylic acid, 7.4 parts of dimethyl 5-sulfoisophthalate, 21 parts of 5-tert-butylisophthalic acid Diformic acid and 20 parts of microencapsulated scandium trifluoromethanesulfonate (scandium trifluoromethane sulfonate) as a heterogeneous catalyst (trade name: SCANDIUM TRIFLUOROMETHANESULFONATE; microencapsulation; carrier: polystyrene; manufactured by Wako Pure Chemical Industries, Ltd. ) production), after nitrogen replacement, the temperature was raised to 100° C. to dissolve it. The temperature was maintained at 100°C and the flask was depressurized to 20 mmHg pressure over 1 hour with stirring. Then, the reaction was continued for 7 hours in this state to obtain crystalline polyester resin 2-(1). The melting point is 68°C.

Recycling Catalysts and Polyester Resins

The crystalline polyester resin 2-(1) obtained above was dissolved in chloroform. The dissolved material was centrifuged to perform filtration, thereby separating the crystalline polyester 2-(1) and the catalyst. The chloroform filtrate was dropped into hexane to recover crystalline polyester resin 2-(1). Furthermore, after washing with chloroform and filtering, the catalyst was dried in vacuo and recovered.

Production of electrophotographic toner

由Junke and Kunkel IKALabortechnic生产)中，在95℃以10000rpm将10份结晶性聚酯树脂2-(1)和90份蒸馏水搅拌3分钟进行乳化，从而得到乳液。向100份该乳液中加入4份铜酞菁颜料(C.I.颜料蓝15:3)分散液(固体含量为0.4份)，并在搅拌下缓慢加入10g 1％硫酸铝水溶液以进行凝集。在60℃搅拌该溶液2小时，控制其pH为4.5，随后逐渐加热，并在95℃加热并搅拌20分钟。此后，在空气中冷却溶液，并用离子交换水清洗，随后冷冻干燥，从而制得电子照相调色剂2-(1)。对于得到的电子照相调色剂，使用库尔特颗粒计数仪(商品名：TA-II型，光圈直径：50μm，由Beckman Coulter Co.，Ltd.生产)测量其平均粒径，得知所得的电子照相调色剂的平均粒径为5.7μm。当用光学显微镜观察调色剂时，证实为球状颗粒形状。In the emulsification device (trade name: ULTRA-

Produced by Junke and Kunkel IKA Labortechnic), 10 parts of crystalline polyester resin 2-(1) and 90 parts of distilled water were stirred at 95° C. for 3 minutes at 10000 rpm for emulsification to obtain an emulsion. To 100 parts of this emulsion was added 4 parts of copper phthalocyanine pigment (CI Pigment Blue 15:3) dispersion (solid content: 0.4 parts), and 10 g of 1% aluminum sulfate aqueous solution was slowly added under stirring for coagulation. The solution was stirred at 60°C for 2 hours to control its pH to 4.5, then gradually heated, and heated and stirred at 95°C for 20 minutes. Thereafter, the solution was cooled in the air, washed with ion-exchanged water, and then freeze-dried to prepare Electrophotographic Toner 2-(1). For the obtained electrophotographic toner, its average particle diameter was measured using a Coulter counter (trade name: TA-II type, aperture diameter: 50 μm, manufactured by Beckman Coulter Co., Ltd.), and the obtained The average particle diameter of the electrophotographic toner is 5.7 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Example 2-2

Synthesis of Crystalline Polyester Resin 2-(2)

Crystalline polyester resin 2-(2) was prepared in a manner similar to the synthesis of crystalline polyester resin 2-(1) in Example 2-1, except that three The consumption of scandium fluoromethanesulfonate is changed to 10 parts. Carboxylic acids and alcohols similar to those of Example 2-1 were used. After nitrogen substitution, the temperature was raised to 100° C. to dissolve. The temperature was maintained at 100°C and the flask was depressurized to 20 mmHg pressure over 1 hour with stirring. The reaction was continued for 7 hours in this state. Its melting point is 66°C.

Recycling Catalysts and Polyester Resins

According to the method similar to Example 2-1, the catalyst and polyester resin were recovered.

Production of electrophotographic toner 2-(2)

Electrophotographic toner 2-(2) was prepared in a similar manner to "Production of electrophotographic toner 2-(1)" in Example 2-1, except that crystalline polyester resin 2-(1 ) was replaced by crystalline polyester resin 2-(2). The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 6.5 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Comparative example 2-1

Synthesis and comparison of crystalline polyester resin 2-(1)

Comparative polyester resin 2-(1) was prepared in a manner similar to that of synthesizing crystalline polyester resin 2-(1) in Example 2-1, except that, as a raw material component, 12.6 parts of non-supported three Scandium fluoromethanesulfonate was used as a catalyst. Carboxylic acids and alcohols similar to those in Example 1 were used. After nitrogen substitution, the temperature was raised to 100° C. to dissolve. The temperature was maintained at 100°C and the flask was depressurized to 20 mmHg pressure over 1 hour with stirring. The reaction was continued in this state for 7 hours to obtain Comparative Polyester Resin 2-(1). Its melting point is 67°C.

Production of electrophotographic toner 2-(3)

Electrophotographic toner 2-(3) was prepared in a similar manner to "Production of electrophotographic toner 2-(1)" in Example 2-1, except that the crystalline polyester resin was replaced with a comparative polymer Ester Resins 2-(1). The average particle diameter of the obtained electrophotographic toner was measured using a Coulter Particle Counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 5.9 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

Comparative example 2-2

Synthesis and comparison of polyester resins 2-(2)

Comparative polyester resin 2-(2) was prepared in a manner similar to that of synthesizing crystalline polyester resin 2-(1) in Example 2-1, except that the catalyst was changed to 10 parts of yttrium trifluoromethanesulfonate as raw material components. Carboxylic acids and alcohols similar to those in Example 2-1 were used. After nitrogen substitution, stirring was carried out at a reaction temperature of 180° C. for 3 hours while mixing and stirring, and polymerization was carried out under reduced pressure for 5 hours. During the 4 hours thereafter, the temperature was finally raised to 220° C., and the final reaction was carried out for a total of 12 hours, thereby synthesizing Comparative Polyester Resin 2-(2). Its melting point is 65°C.

Production of electrophotographic toner 2-(4)

Electrophotographic toner 2-(4) was prepared in a similar manner to "Production of electrophotographic toner 2-(1)" in Example 2-1, except that crystalline polyester resin 2-(1 ) was replaced by comparative polyester resin 2-(2). The average particle diameter of the obtained electrophotographic toner was measured using a Coulter particle counter (trade name: TA-II type, aperture diameter: 50 μm, produced by Beckman Coulter Co., Ltd.) to obtain an average particle diameter of 6.9 μm. When the toner was observed with an optical microscope, a spherical particle shape was confirmed.

The thus-obtained electrophotographic toners 2-(1) to 2-(4) were evaluated for fixing strength, developer performance and image storage property. The evaluations of fixing strength, developer performance and image storability were carried out in accordance with the methods described below.

Assess crease fixation strength

Unfixed solid samples were prepared using a modified digital color copier (trade name: DOCU CENTER COLOR500CP, manufactured by Fuji Xerox Corporation). The mass of toner per unit area in each solid sample is controlled so as to be about 0.7 mg/cm ² to 0.8 mg/cm ² .

The paper used was E COLOR 081 A4 paper (trade name; produced by Fuji Xerox OfficeSupply Co., Ltd.).

The fixing method is as follows. That is, the fixing unit was taken out of the converted machine, and a temperature-controllable fixing station was independently produced and used in an experimental manner. Fixing conditions were controlled so that the image gloss (glossiness) after fixing (measured at 75 to 75 degrees with a device manufactured by Murakami Color Laboratories under the trade name 3GM-260TYPE) was 30%, thereby obtaining a fixed image.

The resulting fixed sample was folded in half, then rolled over the folded portion at a constant speed with a roller (600 mm in outer diameter, and made of brass) weighing about 500 g, and then gently scraped off scraps along the crease , and observe the defect state of the image.

Evaluation was performed by sensory evaluation based on the following criteria.

Evaluation Criteria

A: Creases are generated, but the image has no defect or less image defect.

B: Fine white creases are observed, and cause partial loss of the image.

C: A white band-shaped crease is clearly visible, and a defect is observed in a region on the image whose area is equal to or greater than half of the image.

Evaluating Electrostatic Charge Image Developers

In addition, for the evaluation of the electrostatic charge image developer, image formation was performed using a modified digital color copier (trade name: DOCU CENTER COLOR 500CP, manufactured by Fuji Xerox Corporation), and the initial image (the 10th image) and the 1st image were visually observed. Image quality (fusion irregularities) and background contamination for each of the 50,000 images.

Image quality and background contamination were evaluated according to the following evaluation criteria.

-A: There is no problem with the image.

-B: Although a little contamination was observed, there was no real problem.

-C: The image cannot be used practically because obvious contamination is observed.

Evaluate image storage

Image storability was evaluated as described below. Two sheets of recording paper on which a fixed image was formed at the minimum fixing temperature (MFT (°C)) were stacked with their image sides facing each other, and kept under an environment of a temperature of 60°C and a humidity of 85% with a weight of 100 g/ ^cm2 applied thereon 7 days. The superimposed images were peeled off, and the presence or absence of fusion of the images between the recording sheets and the presence or absence of transfer in the non-image portion were visually observed, followed by evaluation according to the following evaluation criteria.

A: There is no problem with image storage.

B: Although a little change was observed, there was no real problem.

C: The image was practically impossible to use because significant changes were observed.

These results are summarized in Table 2.

Table 2

From the results shown in Table 2, the following are apparent. That is, compared with the electrostatic charge image developers of Comparative Examples 2-1 and 2-2, the image quality of the electrostatic charge image developers of Examples 2-1 and 2-2 showed less solid image portions. Melting irregularity, uniformity is excellent, and shows less background contamination, and image storage and fixing strength are excellent, the developer of the embodiment uses a polyester resin synthesized using a specific heterogeneous catalyst Electrophotographic toner.

Example 2-3

A polyester resin for electrophotographic toner was synthesized in a manner similar to that of Example 2-1, except that the heterogeneous catalyst used in Example 2-1 was changed to trifluoromethanesulfonimide scandium salt . The polyester resin had a melting point of 66°C. Similar to Example 2-2, using the polyester resin, an electrophotographic toner and an electrostatic charge image developer were prepared and evaluated in a manner similar to Example 2-1. The obtained results were similar to those of Example 2-1.

Claims (7)

1. electrofax tinter that comprises adhesive resin and colorant, wherein, described adhesive resin comprises scandium or the yttrium of about 1ppm to 10000ppm, and wherein said adhesive resin comprises the synthetic vibrin of different-phase catalyst of the fluoroform sulfimide salt of the fluoroform sulphonate of employing load scandium or yttrium on carrier or scandium or yttrium.

2. electrofax tinter as claimed in claim 1, wherein, described vibrin is synthetic from acid unit with dicarboxylic acid group and the pure unit with glycol group.

3. electrofax tinter as claimed in claim 2, wherein, described vibrin is crystalline.

4. method of producing electrofax tinter, this method comprises:

Mixed adhesive resin particle dispersion and coloring agent particle dispersion liquid are so that described adhesive resin particle and coloring agent particle aggegation; With

This agglutinating particle is heated to the glass transition temperature that is equal to or higher than described adhesive resin or the temperature of fusing point, so that this agglutinating particle merges,

Wherein, described adhesive resin comprises the scandium of about 1ppm to 10000ppm or yttrium and is used for the vibrin of electrofax tinter, and described vibrin is to adopt the different-phase catalyst of fluoroform sulfimide salt of the fluoroform sulphonate of on carrier load scandium or yttrium or scandium or yttrium synthetic.

5. the method for production electrofax tinter as claimed in claim 4, wherein, described vibrin is synthetic from acid unit with dicarboxylic acid group and the pure unit with glycol group.

6. image forming method, this method comprises:

Keep forming electrostatic latent image on the surface at sub-image;

The developer that use is carried on the developer carrier makes the latent electrostatic image developing that forms on this sub-image maintenance surface to form toner image;

The toner image that forms on this sub-image maintenance surface is transferred to transfer printing to be accepted on the surface of material; And

The toner image of described transfer printing being accepted transfer printing on the material surface carries out hot photographic fixing, wherein,

Described developer comprises carrier and electrofax tinter;

Described electrofax tinter comprises adhesive resin and colorant; And

Described adhesive resin comprises the scandium of about 1ppm to 10000ppm or yttrium and is used for the vibrin of electrofax tinter, and this vibrin is to adopt the different-phase catalyst of fluoroform sulfimide salt of the fluoroform sulphonate of on carrier load scandium or yttrium or scandium or yttrium synthetic.

7. image forming method as claimed in claim 6, wherein, described vibrin is synthetic from acid unit with dicarboxylic acid group and the pure unit with glycol group.