JP2000137348A - Electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner superior in fixability and offset resistance and uniform and stable in chargeability and to obtain a good picture small in fog by using a cross-linked polyester resin as a binder resin having a monocarboxylic ester in the terminal of the molecule. SOLUTION: The binder resin to be used is a cross-linked poly-ester resin having a monocarboxylic acid ester at the terminal of the molecule and the polyester resin comprises a dicarboxylic acid component and a diol component, and further, a monocarboxylic component, a >=3-valent polybasic carboxylic acid and/or a >=3-valent polyol, and it has a chemical molecular structure in accordance with the above components. It is preferred that the binder resin has a glass transition point (Tg) of 50-85 deg.C in order to render blocking resistance and durability at the time of development and it has a softening point of 90-170 deg.C measured by a standard ring and ball method, thus permitting the obtained toner to be superior in fixability and offset resistance and to be charged stably and uniformly and to obtain a good picture small in fog.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-magnetic one-component electrostatic charge developing toner used for electrophotographic development.

[0002]

2. Description of the Related Art Powder toners used in electrophotography are:
In electrical properties such as triboelectric charging and electrical resistance related to development and transfer performance, thermal properties related to fixing performance and heat resistance (storage stability), and powder properties such as fluidity and hardness, An appropriate level according to the use conditions is required.

Conventionally, resin materials used in powder toners include polystyrene, styrene-acrylate copolymer, styrene-butadiene copolymer, polyester, epoxy resin, butyral resin, xylene resin, and cumarone indene. Various proposals have been made for the detailed design of the resin depending on the application.

In particular, resins for heat roll fixing are required to have improved fixing performance to transfer paper and anti-offset performance. In the heat roll fixing, the toner passes between heated and heated heat rollers, and the toner is melted and fixed on paper. At this time, if the roller surface temperature is too low, the toner is not sufficiently heated, an adhesive force is generated only on the surface in contact with the heating roller, and the toner moves to the heating roller side. This is called a cold offset. Conversely, if the temperature of the roller surface is too high, fixing failure occurs if the cohesive force of the toner is lower than the adhesive force to the transfer paper. This is called a hot offset.

The term "offset resistance" means that the toner has a fixing temperature range in which cold offset and hot offset do not occur. A resin having a wide fixing temperature range, that is, a resin having excellent offset resistance is required. .

[0006] Numerous design examples have been proposed to achieve these objects. Among them, in order to maintain viscoelasticity at the time of heating and melting, or to suppress a change in viscosity due to a temperature change,
Techniques such as expanding the molecular weight distribution, providing a crosslinked structure, and applying rubber elastic materials have been studied.

As for electrophotography, US Pat.
297, 691, JP-B-42-23910 and JP-B-43-24748, etc., describe various methods. In general, a photoconductive substance is used and photosensitive is performed by various means. Form an electrostatic latent image on the body,
Next, the latent image is developed with a developer (toner for electrostatic charge development) to form a visible image, and, if necessary, after the visible image is transferred to paper or the like, is fixed by pressing, heating, or solvent vapor, This is to obtain a fixed image.

Although many methods are known as a developing method in electrophotography, they can be roughly classified into fine particles (20 to 500 μm) such as iron powder, ferrite, nickel, and glass.
m), a two-component development method using a mixture of a carrier and a toner as a developer, and a one-component development method using a developer consisting of only a toner. In either method, generally, charge is injected into the toner in a triboelectric manner.

Representative examples of the two-component developing method include a cascade method described in US Pat. No. 2,618,552 and a magnetic brush method described in US Pat. No. 2,874,063. According to these methods, a good image can be obtained stably, but on the other hand, the image quality is deteriorated due to a change in the triboelectrification due to the contamination of the carrier surface by the toner or the like and a change in the mixing ratio of the carrier and the toner. This is likely to occur, and various measures must be taken in terms of equipment and materials in order to prevent this.

The one-component developing method avoids such a problem of the two-component developing method. For example, US Pat. No. 4,336,318 discloses a method using an electrically insulating magnetic toner. A method for developing is described. In these methods, the charge is injected into the toner by frictional charging between the toner particles and the toner carrier and the toner thinning member, or by the frictional charging between the toner particles, so that the electrostatic latent image on the photosensitive member is Electrostatically adheres to

This developing method does not use a carrier and does not require a device for controlling the mixing ratio between the carrier and the toner. Therefore, the problems of the two-component developing method can be avoided and the developing device can be reduced in size. Has the advantage of becoming

On the other hand, in this method, in order to form a magnetic brush layer of a toner on a metal sleeve, it is necessary to impart appropriate magnetic characteristics to the toner itself.
A magnetic material such as ferrite is an essential material in the toner components. The necessary content of these magnetic materials is slightly different depending on the developing conditions and the kind of the materials, but it can be generally said that the required content is 30 to 60% by weight.

However, the inclusion of such a magnetic material, which generally has a low electric resistance and easily absorbs moisture, causes a decrease in the electric resistance and moisture resistance of the toner itself, and as a result, a stable developing performance against environmental changes. It is difficult to obtain, and the image density or the background contamination level greatly varies in various use environments.

The fact that the proportion of the resin material as a binder contained in the toner is smaller than that of the two-component toner is disadvantageous in terms of fixing performance in terms of design. And recently,
In consideration of the increasing use of color images, since many magnetic materials are colored, there arises a problem that colors that can be supported are limited or clear color image quality is difficult to obtain.

In order to solve the problems of the one-component developing method using the magnetic toner, a non-magnetic one-component electrostatic charge developing method that does not require magnetic properties of the toner has been proposed. Various devices have been studied as such a method, but most of the methods use electrostatic force to attach toner to a developing sleeve or the like, transport the toner to a latent image surface, and perform development. The electrostatic charge developing method is greatly different from the electrostatic charge developing method in that the magnetic material is not an essential component in the structure of the toner to be used, and it is expected that various problems caused by the inclusion of the magnetic material can be avoided.

As a non-magnetic one-component electrostatic charge developing method, an electrophotographic powder toner containing a binder resin, a colorant and a charge control agent as essential components is used.

At this time, a polyester resin is used as the binder resin because it is necessary to ensure the stability of charging and the durability during continuous printing. Further, a crosslinked polyester resin is used as a binder resin for a non-magnetic one-component electrostatic charge developing toner used in a heat roll fixing system.

However, when a conventional cross-linked polyester resin, a colorant, and a charge controlling agent are melt-kneaded using a kneader such as a twin screw extruder to produce a toner, a cross-linking reaction of the polyester resin occurs during kneading. In addition, it is necessary to control the number of revolutions of the kneading screw, the torque, the input amount of the raw material, and the like, and it becomes difficult to grind the meat under certain conditions. As a result, the dispersion of the colorant and the charge control agent becomes non-uniform, and when the kneaded material thus obtained is used as a non-magnetic one-component developing type toner and developed, the image density becomes low or fog tends to increase. Problems were easy to arise.

[0019]

DISCLOSURE OF THE INVENTION The present invention is excellent in fixability and offset resistance, and is stably and uniformly charged.
It is an object of the present invention to provide a non-magnetic one-component electrostatic charge developing toner having excellent durability and capable of obtaining a good image with little fog.

[0020]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the terminal of the conventional cross-linked polyester resin is blocked with a monocarboxylic acid, and the terminal monocarboxylic acid ester It was found that the above problems could be solved by making the crosslinked polyester resin
The present invention has been reached.

That is, the present invention relates to a toner for electrostatic charge development comprising at least a binder resin, a colorant, a charge control agent and an external additive, wherein the binder resin has a monocarboxylic acid ester having a molecular terminal. The present invention provides a non-magnetic one-component electrostatic charge developing toner, characterized in that it is a crosslinked polyester resin obtained as follows.

The binder resin used in the present invention is a crosslinked polyester resin in which the molecular terminal is a monocarboxylic acid ester. The polyester resin has, in addition to the dicarboxylic acid component and the diol component, a monocarboxylic acid component and a chemical structure derived from a trivalent or higher polycarboxylic acid and / or a trivalent or higher polyhydric alcohol in a molecular structure. It is characterized by containing.

The crosslinked polyester resin in which the molecular terminal is a monocarboxylic acid ester can be produced by any known and commonly used method, but is usually a trivalent or higher polyvalent carboxylic acid together with a dicarboxylic acid component and a diol component. It is obtained by further reacting an acid and / or a polyhydric alcohol having a valency of 3 or more as a reaction component, followed by further reacting a monocarboxylic acid.

By reacting the monocarboxylic acid component in this manner, a functional group such as a carboxyl group does not exist at the polyester terminal, and even if there is an environmental change during the production of the toner or the use of the toner, the production conditions and Toner characteristics can be stabilized. Specifically, at the time of toner production, for example, a cross-linking reaction that occurs when melt-kneaded together with a colorant and a charge control agent can be suppressed. As a result, in the continuous kneading for a long time, the dispersion of the coloring agent and the charge control agent at the beginning of the meat mixing, the intermediate period, and the latter period becomes uniform, and as a result, a non-magnetic one-component electrostatic charge developing toner with less fog can be obtained. Can be.

The glass transition temperature (Tg) of the binder resin used in the present invention may be appropriately selected, but is preferably 50 to 85 ° C. in order to improve blocking resistance and durability during development. Is preferred. If the temperature is lower than 50 ° C., the blocking resistance deteriorates. For example, in producing the toner, the resin cannot be smoothly supplied to the melt kneading machine, or the toner aggregates during long-term storage, which is not preferable.

The softening point of the binder resin in the present invention may be appropriately selected, but is usually 90 ° C. by a ring and ball method.
As mentioned above, specifically, it is 90-170 degreeC, especially 110-15.
The temperature is preferably set to 0 ° C. If the temperature is lower than 90 ° C., the offset occurrence temperature becomes extremely low, and the fixing temperature range becomes narrow. If the temperature exceeds 180 ° C., it is necessary to fix at a high temperature, which is not preferable from the viewpoint of energy consumption.

In addition, when the temperature is lower than 90 ° C., the toner is liable to cause agglomeration, and when storing or printing, trouble tends to occur. When the temperature exceeds 180 ° C., the fixability often deteriorates.

From these viewpoints, the binder resin in the present invention has a glass transition temperature of 50 to 85 ° C. and a softening point of 9%.
It is preferably a cross-linked polyester resin at 0 to 170 ° C., the molecular end of which is a monocarboxylic acid ester.

The polyester resin as the binder resin used in the present invention is preferably constituted by a combination of the following components, for example. A) Dicarboxylic acid (hereinafter referred to as component A) B) Diol (hereinafter referred to as component B) C) Trivalent or higher polycarboxylic acid (hereinafter referred to as component C) D) Trivalent or higher polyhydric alcohol (hereinafter referred to as component D) E) Monocarboxylic acid (hereinafter referred to as E component)

The components A to E include not only those having a hydroxyl group or a carboxyl group at the terminal but also derivatives such as anhydrides and lower alkyl esters which can form an ester bond as a result. C, D, with respect to the amount of A component and B component
The amount of the E component can be appropriately determined as appropriate.

A of the polyester resin used in the present invention
As the dicarboxylic acid of the component, for example, maleic acid, fumaric acid, mesaconic acid, itaconic acid, glutaconic acid,
Phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid,
Examples include malonic acid, naphthalenedicarboxylic acid, acid anhydrides thereof, a dimer of a lower alkyl ester and linoleic acid, and other divalent organic acid monomers.

B of the polyester resin used in the present invention
As the diol of the component, for example, ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,4-butadiol, neopentyl glycol, 1,4-
Diols such as butenediol, 1,4-bis (hydroxymethyl) cyclohexane, and etherified bisphenols such as bisphenol A, hydrogenated bisphenol A, and polyoxyethylenated bisphenol A;
And a monovalent alcohol monomer.

The tri- or higher valent polycarboxylic acid of component C includes trimellitic acid, trimesic acid, pyromellitic acid, 1,2,4-cyclohexanoic acid tricarboxylic acid, 2,5,7-
Examples include naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, and acid anhydrides thereof.

Examples of the trihydric or higher polyhydric alcohol as the component D include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, Sucrose, 1,2,4-butanetriol, 1,2,5 pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane,
Trimethylolpropane and the like can be mentioned.

As the monocarboxylic acid of the component E,
For example, benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, salicylic acid, thiosalicylic acid,
Examples include phenylacetic acid and lower alkyl esters thereof. The lower alkyl ester referred to here is preferably a non-volatile one, and examples thereof include esters of the above-mentioned monocarboxylic acid and an alcohol having a boiling point of 180 ° C. or less at 1 atm. For example, methyl, ethyl, propyl , N-butyl, isopropyl, tert-butyl and the like. Further, aromatic monocarboxylic acids such as monoammonium sulfobenzoate, monosodium sulfobenzoate, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid, and various fatty acids such as palmitic acid, stearic acid, and oleic acid. Can be mentioned.

Each of the above-mentioned monomers constituting the components A, B, C, D and E can be used alone or in combination of two or more.

The polyester resin used in the present invention is:
For example, it can be produced by reacting the monomers of the components A, B, C, D and E. Specifically, for example, under a nitrogen stream, A, B, C, and D components are polycondensed at 130 to 300 ° C., and then the E component is added, and the softening point of the resin is further increased to 90 to 170 ° C. Or polycondensation to
Component dicarboxylic acid ester, B component and C component, D
After transesterification with the components at 160 to 180 ° C,
Polycondensation at 260-300 ° C., then add E component,
Further, a method of performing polycondensation so that the softening point of the resin is 90 to 170 ° C. may, for example, be mentioned.

In this reaction, oxidized -n
-Butyltin, zinc acetate, cobalt acetate, magnesium acetate, manganese (II) acetate, calcium acetate, antimony trioxide, tetra-n-butoxytitanium and the like can be used.

The monocarboxylic acid as the component E is added to the reaction system when the reaction rate of the reaction mixture comprising A, B, C and D reaches 50% or more, and further when the reaction rate becomes 80% or more. In addition, it is preferable to react.

The non-magnetic one-component electrostatic charge developing toner of the present invention uses the polyester resin obtained as described above as a binder resin.

As the coloring agent used in the present invention, various non-magnetic organic pigments and inorganic pigments can be used. Specifically, for example, carbon black, aniline blue, calcoyl blue, chrome yellow, ultra Marine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue,
Malachite green oxalate, lamp black, rose vengara, disazo yellow, quinacridone red, pigment red 122, C.I. I. Pigment Yellow 97, C.I. I. Pigment Blue 15, C.I. I. Pigment Yellow 180 and the like, and one kind or a combination of two or more kinds can be used.

Examples of the carbon black include Mogal L, ELFTEX 8 (above, manufactured by Cabot Corporation, USA), and MA100 (manufactured by Mitsubishi Chemical Corporation).

In the toner of the present invention, the weight ratio between the binder resin and the colorant is not particularly limited, but is usually 1 to 60 parts by weight, preferably 3 to 30 parts by weight, per 100 parts by weight of the binder resin. .

As the charge control agent used in the present invention,
For example, known and commonly used charge control agents such as nigrosine dyes, quaternary ammonium salts, trimethylethane dyes, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex salt azo dyes, and heavy metal-containing acid dyes such as azochrome complexes. However, in order to achieve the object of the present invention, it is preferable to use the charge control agent of Formula 1 as an essential component, and it is particularly preferable to use two types of charge control agents of Formula 1 and Formula 2 below.

Chemical formula 1

[0046]

Embedded image

Chemical formula 2

[0048]

Embedded image

[NH ₄ , Na, H] ^{+ in} Chemical Formula 2 is N
H ₄ , Na, or H.

The weight ratio of each charge control agent is not particularly limited, but preferably, when the total weight of the two charge control agents represented by the above chemical formulas 1 and 2 is 100, the ratio is 40/40. It is desirable to use at 60-60 / 40 (weight ratio).

Further, it is desirable to use 0.5 to 3 parts by weight of these in total per 100 parts by weight of the solid content of the binder resin.

In obtaining the toner of the present invention, various auxiliary agents such as a charge controlling agent, a releasing agent, and a fluidity improving agent can be added in any step of the production. It is effective to attach the fluidity improver to the toner surface.

Further, in the application for heat roll fixing, various waxes are used as necessary as an auxiliary agent for enhancing the releasing effect in order to prevent troubles due to toner adhesion to the heat roll (offset). Natural waxes such as ester waxes, polyolefin-based waxes such as high-pressure polyethylene and polypropylene, silicone-based waxes, and fluorine-based waxes can be used.

Suitable waxes include, for example, Viscol 660P, Viscol 550P, Viscol 330
P, TP-32 (manufactured by Sanyo Chemical Industries, Ltd.), Mitsui High Wax NP505, P200, P300, P4
00 etc.

The wax used in the present invention has a viscosity of 50 to 50.
00 mPa · s is preferred. When the viscosity of the wax is 50 mPa · s or less, the wax easily adheres to a developing roller or a blade, and a defective image such as a black streak tends to occur. Also, the viscosity of the wax
If it is 5000 mPa · s or more, the dispersion in the binder resin becomes poor, the offset resistance becomes poor, and the effect of the present invention cannot be sufficiently obtained.

Examples of the lubricant include metal soap and zinc stearate, and examples of the abrasive include cerium oxide,
Silicon carbide and the like can also be used.

The toner of the present invention can be obtained by any known and commonly used manufacturing method. For example, the binder resin, the colorant and the charge controlling agent are mixed at a temperature higher than the melting point (softening point) and lower than the decomposition point of the binder resin. , And then pulverized and classified. Of course, it may be manufactured by other methods.

Specifically, for example, the binder resin, the colorant, and the charge control agent are mixed as essential components by a kneading means such as a two-roll, three-roll, pressure kneader, or a twin-screw extruder. . At this time, the colorant may be uniformly dispersed in the binder resin, and the conditions for the melt-kneading are not particularly limited. However, the entire raw material mixture that needs to be kneaded is at least the softening point of the resin component or more, usually 80 or more.
To 190 ° C. and kneading until uniform, but the temperature immediately before taking out the kneaded material should be 150 to 180 ° C., and 10 minutes to 50 hours from the start to the end of kneading. preferable.

A conventional crosslinked polyester resin having a functional group capable of reacting at the molecular terminal, if it is kept in a uniformly kneaded state, assuming continuous production overnight, etc.
In about 4 to 7 hours from the start of kneading, a cross-linking reaction such as a gelling phenomenon of a resin often occurs in many cases. Often not obtained. On the other hand, the specific resin used in the present invention suppresses such a crosslinking reaction. As a result, once the resin is stably dispersed, even if the heat load (heat history) is further applied for a long time. There is an advantage that a stable dispersion state is maintained and the above-mentioned inconvenience hardly occurs even under the same conditions from the beginning to the end.

When a release agent is included, kneading is performed, for example, by mixing the binder resin, the colorant, and the release agent with 1 to 10% by weight of the colorant, 0.5 to 5% by weight of the release agent, What is necessary is just to prepare beforehand so that the remainder may become a binder resin and a charge control agent.

Then, after cooling, the mixture is finely pulverized by a pulverizer such as a jet mill and classified by an air classifier or the like. The average particle diameter of the toner particles is 1
~ 15 µm is preferred.

The toner powder of the present invention can be used as it is as a powder toner for electrophotography. However, the powder fluidity can be further improved by externally adding an external additive so that the toner powder can be used practically. The above is preferable.

As the external additive used in the present invention, any known and commonly used external additives include silicon dioxide (silica), titanium dioxide and the like. Preferably, the external additive is hydrophobic among silicon dioxide. Examples thereof include hydrophobic silica fine particles obtained by surface-treating silicon dioxide with various polyorganosiloxanes, silane coupling agents, or the like. For example, there is one that is commercially available under the following trade names.

AEROSIL R972, R974, R
202, R805, R812, RX200, RY20
0, R809, RX50 [Nippon Aerosil Co., Ltd.]

WACKER HDK H2000, H2
050EP [Wacker Chemicals East Asia Co., Ltd.] Nipsil SS-10, SS-15, SS-20,
SS-50, SS-60, SS-100, SS-50
B, SS-50F, SS-10F, SS-40, SS-
70, SS-72F [Nippon Silica Industry Co., Ltd.]

As typical silicas as the above-mentioned external additives, there are silica having a relatively large average particle diameter and silica having a relatively small average particle diameter. These may be used alone or in combination. Good. In the present invention, it is preferable to use hydrophobic silica fine particles having a primary particle average particle diameter of 5 nm to 50 nm, and those having a relatively large average particle diameter and those having a relatively small average particle diameter. Particularly preferred is the combined use with. As the amount of external addition of silica, a charge amount is necessary and sufficient, and there is no possibility of damaging the photosensitive drum or deteriorating the environmental characteristics of the toner. 1-5.0
Parts by weight are practically preferred.

As a method for externally adding the silica to the toner particles, for example, a conventional powder mixer such as a Henschel mixer or a so-called surface modifier such as a hybridizer can be used. The external addition may be such that silica adheres to the surface of the toner particles, or a part of the silica may be embedded in the toner particles.

As a one-component developing method using a non-magnetic toner, there is a contact-type non-magnetic one-component developing method in which a developing sleeve carrying a developer is brought into contact with a photosensitive drum having an electrostatic latent image to perform development. .

The toner obtained by the present invention allows the toner to pass between the developing sleeve and the charging member pressed against the developing sleeve, and frictionally charges the toner to form an electrostatic latent image formed on the surface of the photoreceptor. Can be particularly effectively used in a contact-type non-magnetic one-component developing method for developing a toner.

[0070]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention includes the following embodiments. 1. At least, a toner for electrostatic charge development containing a binder resin, a colorant, a charge control agent, and an external additive, wherein the binder resin is a cross-linked polyester resin in which a molecular terminal is a monocarboxylic acid ester. A non-magnetic one-component electrostatic charge developing toner.

2. A polyester obtained by further reacting a monocarboxylic acid after the binder resin has reacted as a reaction component a trivalent or higher polycarboxylic acid and / or a trivalent or higher polyhydric alcohol together with a dicarboxylic acid component and a diol component. 2. The non-magnetic one-component electrostatic charge developing toner according to 1 above, which is a resin.

3. 3. The non-magnetic one-component electrostatic charge developing toner according to 1 or 2, wherein the binder resin is a polyester resin having a Tg of 50 ° C. or more and a softening point of 90 to 170 ° C.

4. As the charge control agent, the above chemical formula 1
4. The toner for negatively charged non-magnetic one-component electrostatic charge development according to the above 1, 2 or 3, which contains the compound represented by the formula:

5. As the charge control agent, the above chemical formula 1
4. The toner for negatively charged non-magnetic one-component electrostatic charge development according to the above 1, 2 or 3, wherein the compound represented by the formula (2) or (2) is used in combination.

6. The external additive has a primary particle average particle size of 5n.
The above 1, 2, which are hydrophobic silica fine particles having a diameter of m to 50 nm.
6. The non-magnetic one-component electrostatic charge developing toner according to 3, 4 or 5.

7. At least, a crosslinked polyester resin in which the molecular end is a monocarboxylic acid ester, a colorant, and a charge control agent are pulverized and classified at 150 to 180 ° C. for 10 minutes to 50 hours, and then optionally classified. 3. A method for producing a non-magnetic one-component electrostatic charge developing toner, comprising adding an external additive in the step (a).

8. The crosslinked polyester resin in which the molecular terminal has become a monocarboxylic acid ester has reacted a tricarboxylic or higher polycarboxylic acid and / or a trihydric or higher polyhydric alcohol as a reaction component together with a dicarboxylic acid component and a diol component. 8. The method according to the above 7, wherein the polyester resin is obtained by further reacting a monocarboxylic acid.

9. 9. The method according to the above item 7 or 8, wherein the binder resin is a polyester resin having a Tg of 50 ° C. or more and a softening point of 90 to 170 ° C.

10. 10. The production method according to the above 7, 8 or 9, comprising a compound represented by the above chemical formula 1 as the charge control agent.

11. The above 7, 8 or 9 wherein the compounds represented by the above formulas 1 and 2 are used in combination as the charge control agent.
The manufacturing method as described.

12. The external additive has a primary particle average particle diameter.
The above 7, which is a hydrophobic silica fine particle having a diameter of 5 nm to 50 nm,
The production method according to 8, 9, 10 or 11.

13. At least, a cross-linked polyester resin having a molecular carboxylate ester, a colorant and a charge control agent, at 150 to 180 ° C. for 10 minutes to 50 hours, pulverizing and classifying the melted and kneaded colored resin composition, A method for producing a non-magnetic one-component electrostatic charge developing toner, comprising adding an external additive.

14. The external additive has a primary particle average particle diameter.
14. The production method according to the above 13, wherein the silica fine particles have a diameter of 5 nm to 50 nm.

[0084]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. In the following, numerical values in the composition table represent "parts by weight" and "% by weight", respectively. An example of the synthesis of the binder resin used for preparing the toner first is shown below.

(Resin Synthesis Example 1) Polyoxyethylene
(2,0) -2,2-bis (4-hydroxyphenyl)
4.8 mol of propane, 2.4 mol of isophthalic acid, 2.4 mol of terephthalic acid, and 0.07 wt% of dibutyltin oxide were gradually heated under a nitrogen stream, and reacted at 220 ° C. for 3 hours. To this is added 0.1 mol of trimellitic anhydride, and then 220 ° C.
For 1 hour. After confirming that 80% or more of these raw material components have reacted and that a hydroxyl group is present,
0.05 mol of benzoic acid was charged and reacted at 220 ° C. for 1 hour to obtain a polyester resin.

The obtained polyester resin had a crosslinked structure based on trimellitic anhydride, and it was confirmed that a benzoic acid ester was present at the molecular terminal.

The polyester resin thus obtained is referred to as “resin A”. Resin A was a solid at room temperature, and had a glass transition temperature of 62 ° C by DSC measurement and a softening point (ring and ball method) of 137 ° C.

(Resin Synthesis Example 2)
A polyester resin was synthesized in the same manner as in Resin Synthesis Example 1 except that 0.1 mol of oleic acid was used instead of 0.05 mol of benzoic acid. The obtained polyester resin had a crosslinked structure based on trimellitic anhydride, and the presence of a portion having an oleic ester at the molecular terminal was confirmed.

The polyester resin thus obtained is referred to as “resin B”. Resin B was a solid at room temperature and had a glass transition temperature of 63 ° C and a softening point of 138 ° C.

(Example 1) 92 parts by weight of resin of Resin Synthesis Example 1 5 parts by weight of carbon black Mogal L (manufactured by Cabot Chemicals Chemicals, Inc.) Charge control agent 1 part by weight of charge control agent of the above chemical formula 1 Wax Biscol 550P (manufactured by Sanyo Chemical Industries, Ltd.) 2 parts by weight

Are mixed in a Henschel mixer, and kneaded in a twin-screw kneader so that the temperature of the kneaded material immediately before taking out is 160 ° C. The kneaded material thus obtained is pulverized and classified to obtain toner powder A.

100 parts by weight of toner powder 1 part by weight of silica NAX50 2 parts by weight of silica R972 were mixed with a Henschel mixer and then sieved to obtain a toner A.

(Example 2)

Toner B was obtained in the same manner as in Example 1 except that the resin of Resin Synthesis Example 2 was used as the binder resin instead of Resin Synthesis Example 1.

(Example 3) Except that in Example 1, 0.6 parts by weight of the charge control agent of the above formula 2 (the counter cation is H ⁺ ) was used as a charge control agent, and 0.6 parts by weight of the charge control agent of the above formula 1 was used. In the same manner as in Example 1, a toner C was obtained.

Comparative Example 1 A resin for comparison was synthesized in the same manner as in Resin Synthesis Example 1 except that benzoic acid was not used.
This is designated as Comparative Resin 1. Comparative Example 1 A toner was produced in the same manner as in Example 1 except that Comparative Resin 1 was used instead of the resin of Resin Synthesis Example 1 as the binder resin. In addition, when the temperature of the kneaded material immediately before taking out was set to 160 ° C., a gelling phenomenon was observed in 6 hours.

Comparative Example 2 A toner was produced in the same manner as in Example 3, except that Comparative Resin 1 was used as a binder resin, to obtain Comparative Toner 2.

The kneaded material 2 hours and 30 hours after the start of kneading of the above-mentioned Examples and Comparative Examples was pulverized, classified, and externally added. The fog density and the degree of dispersion of the charge control agent were evaluated. Table 1 shows the evaluation results.

Next, the image density and the fog density were measured with a Macbeth image densitometer RD-918. The degree of dispersion of the charge control agent was determined by visual observation with a microscope.

[0100]

[Table 1] Table 1

As can be seen from a comparison between the Examples and Comparative Examples, the toner of the present invention suppresses the crosslinking reaction of the resin even during long-term continuous kneading during production, and as a result, the carbon and the charge controlling agent lose their thermal aging characteristics over time. The stable dispersed state is maintained irrespective of the toner, so when developed as a non-magnetic one-component electrostatic charge developing toner, stable image density and fog density are exhibited.

[0102]

According to the present invention, since the binder resin is a cross-linked polyester resin having a monocarboxylic acid ester at the molecular terminal, unlike the conventional cross-linked polyester resin having a reactive functional group at the molecular terminal, Excellent environmental stability can be obtained, and furthermore, the crosslinking reaction of the resin is suppressed even during the long-term continuous kneading during the production of the toner, and as a result, the carbon and the charge control agent are stably dispersed. Therefore, when the toner is developed as a non-magnetic one-component electrostatic charge developing toner, a particularly remarkable effect of exhibiting stable image density and fog density is exhibited.

Claims (6)

[Claims] 1. An electrostatic charge developing toner comprising at least a binder resin, a colorant, a charge control agent, and an external additive, wherein the binder resin has a monocarboxylic acid ester at a molecular end. A non-magnetic one-component electrostatic charge developing toner, which is a cross-linked polyester resin. 2. After the binder resin reacts with a dicarboxylic acid component and a diol component as well as a trivalent or higher polyvalent carboxylic acid and / or a trivalent or higher polyhydric alcohol as a reaction component, the monocarboxylic acid is further reacted. The non-magnetic one-component electrostatic charge developing toner according to claim 1, which is a polyester resin reacted. 3. The non-magnetic one-component electrostatic charge developing toner according to claim 1, wherein the binder resin is a polyester resin having a Tg of 50 to 85 ° C. and a softening point of 90 to 170 ° C. 4. The negatively charged non-magnetic one-component electrostatic charge developing toner according to claim 1, wherein the charge control agent comprises a compound represented by the following chemical formula 1. Chemical formula 1 5. The charge control agent according to the following chemical formulas 1 and 2
4. The toner for negatively charged non-magnetic one-component electrostatic charge development according to claim 1, wherein the compound represented by the formula (1) is used in combination. Chemical formula 1 Chemical formula 2 [NH ₄ , Na, H] ^{+ in} Chemical Formula 2 is NH ₄ , Na,
H. 6. The external additive has a primary particle average particle diameter of 5 nm to 5 nm.
The hydrophobic silica fine particles having a particle diameter of 0 nm,
6. The non-magnetic one-component electrostatic charge developing toner according to 3, 4 or 5.