JPH03214167A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To improve humidity dependency of electric charging characterisitcs, fluidity, insulation property, and the like, and to enhance fixability, sharp meltability, and offset resistance by incorporating a resin base composed essentially of polyester specified in softening point and glass transition point and specifying the size distribution of the toner >=70 number average % of particle distribution in the specified range. CONSTITUTION:The polyester resin A to be used for the main component of the resin base has a softening point of 80-150 deg.C and a glass transition point of >=40 deg.C, and it has an average particle diameter D of 1-30 mum and the particles in the particle diameter of 0.5-2.0D are contained in >=70 number average % of the total particles. The electrophotographic toner is manufactured by dyeing these particles with a dye, thus permitting the obtained electrophotographic toner to be improved in the humidity dependency of charging characteristics, fluidity characteristics, insulation property, and the like and to be enhanced infixability, sharp meltability, and offset resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to toner. More specifically, the present invention relates to a toner used as a developer in electrophotographic copying machines, laser printers, and the like.

(Prior art) In general, electrophotography is a photoconductive material that uses a carrier system such as selenium, amorphous silicon, or zinc oxide, or an organic system (often processed into a drum shape) such as a diazo compound or dye. First, the substance (photosensitive drum) is charged in a negative manner,
Next, an electrostatic latent image is formed by irradiating image-modulated light, and developed by attaching powder to the electrostatic latent image using electrostatic force. After the powder is transferred onto the paper, it is fixed by applying pressure, heating, or other methods. Electrophotographic methods are currently widely used in copying machines, laser printers, and the like.

In electrophotography, a powder that develops an electrostatic latent image on a photosensitive drum and is ultimately transferred to a base material such as paper or film to form an image is called a toner. These toners are usually mixed with carrier particles (carrier) such as glass beads, iron powder, ferrite, etc., and used as a so-called developer.

Conventionally, toners used in electrophotographic developers include:
Particles are produced by the so-called pulverization method, which involves adding colorants, charge control agents, fluidity modifiers, pulverization aids, etc. to thermoplastic resins, kneading them, pulverizing them, and then classifying them. Ta. Or in 4th year, some emulsion polymerization method,
Research on toners using suspension polymerization methods, seed methods, etc. is being conducted.

These toners require various physical or chemical "properties."

As described above, the process of copying one image in electrophotography is a series of electrostatic transfers of charged toner. Therefore, there are many requirements for the charging characteristics of toner. Various methods have been proposed and put into practical use for imparting charge to toner, but in most cases friction with carrier particles (carrier), which are mixed together to form a developer, is used. A common method is to charge the battery with electricity. In this case, it is desirable that the amount of charge on the toner be constant regardless of the degree of friction or time. This is because when the amount of charge on the toner changes, the amount of toner that adheres to the electrostatic latent image on the photosensitive drum changes.
This is because variations in the density of the copied image occur.

In order to quickly perform frictional charging with carrier particles (carrier), it is also necessary to quickly transfer the electrostatic latent image on the photosensitive drum 1- or onto a substrate such as paper or film from the photosensitive drum ↓. In order for this to occur, the toner naturally needs to exhibit good fluidity.

The electrostatic latent image on the photosensitive drum-L and the toner are combined by electrostatic force. Therefore, when transferring to a substrate such as a photosensitive drum, paper, or film, a bias voltage may be applied to the substrate (II).The substrate and toner must have sufficient insulation to withstand this voltage. Due to the nature of paper, which is often used as a base material, humidity greatly reduces its insulation properties.Therefore, this insulation property is actually -
Only the L toner will be responsible.

The toner transferred onto the base material is fixed by heating, applying, or the like. The heated or pressurized toner needs to quickly melt or plastically deform and adhere to the base material. At this time, the quality of the image must not be degraded by lowering the viscosity more than necessary. At the same time, it must not adhere to the fixing roll side.

Of course, the characteristics required of these toners mentioned above must not change even during long-term storage or repeated use.
The image quality must be maintained for a long period of time even after the image is copied. Also, there must be no transfer or transfer to other locations.

When copying a color image, the three primary colors of subtractive color mixing,
You need to have toner for each color: cyan, magenta, and yellow. Similar to process inks for printing, these color toners are required to have predetermined reflection spectral characteristics and color reproducibility when overlapping colors. Also, these color toners.

It is also necessary to have excellent spectral transmission characteristics in case the image is to be observed by copying it onto a transparent film and projecting it onto a screen using an overhead projector.

In recent years, there has been a trend for toners to have smaller particle sizes and sharper particle size distributions in order to improve the quality of copied images.

Furthermore, it is out of the question that these toners, which form the copied images themselves, contain toxic and deleterious ingredients that may be harmful to the human body or impair health; it is needless to say that these toners must have the highest level of safety and hygiene. Not even.

(Problems to be Solved by the Invention) The characteristics required of toner have been described above, but toners conventionally used do not completely satisfy them.

With many toners, during repeated development due to continuous use, the density of the resulting image may change or change due to mutual deterioration of the toner, carrier particles, and photosensitive drum surface due to collisions between the toner and carrier particles and the mutual deterioration of the toner, carrier particles, and photosensitive drum surface. The background 1 degree increases and the image quality becomes low F.

Attempting to increase the 1 degree of the reproduced image by increasing the number of toner bottles adhering to the electrostatic latent image on the photosensitive drum usually results in an increase of 1 degree of the background. Cow the so-called Kabuli.

+18 When transferring toner from the electrostatic latent image on optical drum L to a base material such as paper by applying a bias voltage, especially in a situation where the insulation properties of the base material have decreased due to the influence of iW degree,
Because the toner does not have sufficient insulation, discharge occurs between the toner and the photosensitive drum, and the charge on the photosensitive drum L is neutralized, destroying the electrostatic latent image and causing it to stick to the electrostatic latent image. The toner that was being used may be scattered, and as a result, the quality of the copied image may be extremely poor (so-called self-dropping).

Regarding the fixing of toner transferred onto a base material such as paper or film, it is necessary to control the softening temperature of the toner, and more specifically, to strictly control the relationship between temperature and melt viscosity. More specifically, it functions as a solid up to the fixing temperature,
In addition, it is required to have so-called sharp melt characteristics, which means that the material melts quickly at a predetermined fixing temperature, but it is difficult to achieve this, and in reality, fixing is performed at a considerable temperature. is the current situation.

Furthermore, because the fixation to the base material is given too much priority, the adhesion to the fixing roll is hardly perfect.

In many cases, in order to solve this problem, measures are taken such as applying a release aid such as silicone oil to the fixing roll. In that case, adhesion of the release aid to the base material becomes a problem. Furthermore, maintenance of the device becomes troublesome, such as the need to periodically replenish the mold release aid.

Toners with low softening temperatures tend to aggregate during handling or storage due to their tendency to melt easily with heat, especially during long-term storage.
Liquidity will deteriorate significantly.

Furthermore, the triboelectric charging properties and flow characteristics of many toners deteriorate due to the influence of environmental temperature and humidity.

Toners intended for the reproduction of color images are often colored with pigments.

In this case, it is relatively easy to obtain predetermined reflection spectral characteristics in each of the three subtractive primary colors, cyan, magenta, and yellow. However, in many cases, poor transparency causes problems in transmission spectral characteristics, resulting in unacceptably low color reproducibility when overlapping colors. This effect is most severe in the reproduction of intermediate colors. Furthermore, when an image copied onto a transparent film L using color toners with poor transmission spectral characteristics is observed by projecting it onto a screen L using an overhead projector, etc., the color tone becomes dim, muddy, and poor in clarity. . Regarding the transmission spectral characteristics of color toners, if the transparency of the resin itself, which is one of the components of the toner, is good, a certain degree of improvement can be expected by reducing the particle size of the pigment. However, with this method, it is not possible to avoid a significant increase in toner manufacturing cost tJ+'.

In order to improve the quality of reproduced images, toners with smaller particle sizes have been strongly sought after in recent years, and the issue of production cannot be left out of the discussion. That is, in the pulverization method that has been used as a toner production method in many cases, it is difficult to industrially obtain particles with an average particle size of about 10 or less. If the resin itself is simply pulverized, it is not difficult to obtain more than 10 mills using the current pulverizers.

However, since not all of the pulverized particles have the desired particle size, a classification operation is naturally required. This means that the retention rate will drop significantly. Furthermore, when producing toner with a fine particle size using the pulverization method, coloring agents, charge control agents, fluidity modifiers, pulverization aids, etc. added to the thermoplastic resin, which is the main component, are required in advance. It must be ground to a size smaller than the particle size, which inevitably increases production costs. These reasons make it difficult to industrially produce toner having a fine particle size by the pulverization method.

The shape of the toner obtained by the pulverization method is naturally amorphous and only exhibits a broad particle size distribution.

Research on toners using emulsion polymerization, suspension polymerization, and/or depolymerization methods, which has been carried out in some areas in recent years, is aimed at addressing the problems of the pulverization methods mentioned above. It is.

Particles obtained by the polymerization method have excellent fluidity because they are spherical in shape, and can therefore be expected to have uniform triboelectrification.Furthermore, by appropriately controlling polymerization, it is possible to control thermal melting characteristics, etc. It can be expected to have similar characteristics.

In the emulsion polymerization method, polymerizable monomers are fused in micelles stabilized with a surfactant in water to obtain fine powder particles.

In the emulsion polymerization method, particles having a sharp particle size distribution can be obtained. However, since the particle size is determined by the size of micelles that can exist stably, the particle size is limited to a range of about 0.01 to 0.5 mm, and particles with a particle size of about 111 M or more are created. That is difficult. Since the number of particles required for a toner is limited to approximately several particles to a dozen particles, particles obtained by the emulsion polymerization method cannot be used as they are in an electrophotographic toner.

Furthermore, if a surfactant essential for stabilizing micelles remains on the particle surface, it may affect the fluidity or charging characteristics of the particles.

In the suspension polymerization method and the suspension system obtained by stirring water and a polymerizable monomer, polymerizable! This is a method of obtaining particles by polymerizing a li-mer. In suspension polymerization, polymerization in a stable system is not easy, and it is technically difficult to obtain fine polymer particles with a uniform particle size distribution through polymerization. The reason for this is that coalescence of particles occurs during granulation. For example, to prevent particle coalescence and stabilize polymerization! ! ! In turbid polymerization, when polymerizable monomers are polymerized in an aqueous dispersion system, in order to prevent particles from coalescing as the polymerization progresses! ! ! Use turbidity stabilizer.

Suspension stabilizers generally include sparingly soluble inorganic compounds such as sparingly soluble salts such as barium sulfate, calcium sulfate, magnesium carbonate, barium carbonate, calicylum carbonate, potassium phosphate, silica, calcia, magnesia, titanium oxide, etc. metal oxides, minerals such as diatoms, talc, clay, kaolin, and mixtures thereof, or water-soluble mixtures such as polyvinyl alcohol, gelatin, starch, etc. are used. these! ! ! It is known that turbidity stabilizers have a negative effect on the charging characteristics of particles if they remain on the particle surface, so it is essential to wash the polymer particles after soaking them, but it is impossible to completely remove them. Very difficult. In reality, even when these suspension stabilizers are used, the particle size range of the particles obtained by suspension polymerization is approximately several 10 mm or more, and the particle size distribution is also broad, so electrophotography It is difficult to obtain particle sizes in the range of several tens to hundreds of thousands, which is required for toners for commercial use.

The seed polymerization method is a polymerization method proposed to solve these problems. In the seed polymerization method, for example, particles obtained by other methods such as emulsicon polymerization are used as seed particles, the seed particles are swollen with a solvent and a polymerizable monomer, and polymerization is carried out within the swollen seed particles. This is a method of growing seed particles to make them thicker. In the seed polymerization method, by selecting appropriate seed particles, particles with a sharp particle size distribution can be obtained. It is possible to control the swelling rate of the seed particles'f-heptapolymerizable body.

However, the swelling rate of seed particles cannot be increased unnecessarily. For example, increasing the particle diameter by 1 corresponds to increasing the volume. When the seed particles are swollen to a certain extent by the polymer during polymerization, the seed particles are no longer able to maintain their particle shape and may even break. In other words, the swelling rate cannot be increased extremely, and there is a natural limit to the particle size range that can be grown at a rate of 2 to 3 degrees.
It's about double that. If it is desired to grow larger particles, it is necessary to repeat seed polymerization.

In seed polymerization, it is technically possible to obtain particles with a sharp particle size distribution in the particle size range of several to several dozen particles. However, it is not easy to find suitable particles as seed particles, and the manufacturing cost is enormous due to the complexity of the process.
It cannot be used as a method of supplying toner for electrophotography on an industrial level.

In other words, the number of toners required for electrophotography is
It is very difficult to industrially produce particles with a sharp particle size distribution in the particle size range of one to several sizes at a low cost using conventional polymerization methods.

Further, resin particles obtained by conventional polymerization methods are limited to so-called vinyl resin particles, typified by styrene/acrylic resins and the like.

Moreover, for the resin particles obtained by these polymerization methods, 1
Charge control agents, colorants, offset inhibitors,
It is not easy to add fluidity improvers and the like. That is, the present situation is that even resin particles obtained by conventional polymerization methods have not yet solved many of the problems required of toners.

As mentioned above, conventional toners have various characteristics such as humidity resistance, that is, humidity dependence such as charging characteristics, flow characteristics, and insulation, as well as fixing characteristics, sharp melt characteristics, offset resistance, particle size distribution, transparency, and color. This method has many problems in terms of reproducibility, manufacturing cost, etc.

In view of this situation, the inventors of the present invention have conducted extensive research in order to obtain a toner that comprehensively satisfies many of these required characteristics and can be produced industrially, and as a result, they have arrived at the following invention.

(Means for Solving the Problems) That is, the present inventor has discovered that the present invention contains as a base material a resin (A) whose main component is a polyester having a softening point of 80 to 150°C and a glass transition point of 40°C or higher, and Particle size is 1~30u
and the average particle size is 0.5D to 2.0D when D-pickled.
An electrophotographic toner characterized in that particles having a particle size falling within the range of 70% or more on the number average exist, and further characterized in that the toner is dyed with a dye. .

The toner of the present invention is made of a polyester resin, especially a softening point of 4.
It is a toner obtained by dyeing particles of a polyester resin having a temperature of 0°C or higher and a glass transition point of 80 to 150°C, and the particles as a base material have an average particle size of 1 to 301 JJa, and an average particle size of I ), particles having a particle size falling within the range of 0.5D to 2.0D account for 70% or more on the number average. The particles are preferably substantially spherical particles with a number average of 70% or more having a sphericity of 0.7 or more.

In the present invention, substantially spherical particles having a number average of 70% or more of particles having a sphericity (ratio of major axis to minor axis) of 0.7 or more,
When the average particle size is D, the diameter is from 0.5D to 2.0D.
As a method for obtaining polyester resin particles having a sharp particle size distribution in which particles with a particle size falling within the range of 70% or more of the total number are In the dispersion, the equivalent ratio of the vinyl monomer containing the counterion group of the resin is 0.8.
An example of a method for manufacturing by polymerizing 2.0 from

Here, the polyester resin is not limited to any particular polyester, but it is preferably one whose main component is a polyester consisting of a dicarboxylic acid resin and a glycol component.

Examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and 1,5-naphthalic acid, and aromatic oxycarboxylic acids such as p-oxybenzoic acid and p-(hydroxyethoxy)benzoic acid. acids, succinic acid, adipic acid, azelaic acid, sebacic acid,
Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, unsaturated aliphatic acids such as fumaric acid, maleic acid, itaconic acid, hexahydrophthalic acid, tetrahydrophthalic acid, and
Examples include alicyclic dicarboxylic acids.

If necessary, a small amount of tri- and tetracarboxylic acids such as trimellitic acid, trimesic acid, and pyromellitic acid may be included.

Glycol components include, for example, ethylene glycol, propylene gellicol, 1.3-propanediol, 1.
4-butanediol, 1.5-bentanediol, 1.
8-hexanedio-7, neohentyl glycol, diethylene glycol, dipropylene glycol, 2,2
．． 4-trimethyl-1,3-bentanediol, ■, 4
-cyclohexanenomethanol, spiroglycol, 1
4-Phenylene glycol, ethylene oxide adducts of 1,4-phenylene glycol, diols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide adducts and propylene oxide adducts of bisphenol A,
Examples include ethylene oxide adducts and propylene oxide adducts of hydrogenated bisphenol A.

If necessary, a small amount of triol and tetraol such as trimethylolethane, trimethylolpropane, glycerin, and pentanylthritol may be included.

Other examples of polyester polyols include lactone-based polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone.

The ionic groups contained in the polyester resin include carboxyl groups, sulfonic acid groups, sulfuric acid groups, phosphoric acid groups, anionic groups of their bases, or cationic groups such as primary to tertiary amine groups. and preferably,
Sulfonic acids and their metal bases.

Examples of sulfonic acids and their metal base-containing aromatic dicarboxylic acids that can be copolymerized with polyester include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid,
Examples include -sulfonaphthalene-2,7 dicarboxylic acid, 5(4-sulfophenoxy]isophthalic acid, etc., and their metal salts. Examples of the metal salts include Lis Na1K
s Mg.

Examples include salts such as Ca1CusFe. Particularly preferred is 5-sodium sulfoisophthalic acid.

The amount of the aromatic dicarboxylic acid containing a sulfonic acid metal group is not particularly limited as long as a dispersion, particularly an aqueous dispersion, can be obtained, but it is suitably within the range of approximately 20 to 500 equivalents/1,000,000 g.

In the present invention, the polyester resins can be used alone or in combination of two or more if necessary.

Further, it can be mixed with amino resins, epoxy resin incyanate compounds, etc. in a molten state or a solution state, and furthermore, it can be partially reacted with these compounds. The obtained partial reaction product can also be used as a raw material for an aqueous dispersion.

The aqueous dispersion containing the ionic group-containing polyester of the present invention as a main component can be produced by any known method. That is, by mixing polyester and a water-soluble organic compound in advance at 50 to 200°C and adding water to this, or by adding a mixture of polyester and a water-soluble organic compound to water and stirring at 40 to 120°C. Manufactured.

Alternatively, it can also be produced by adding polyester to a mixed solution of water and a water-soluble organic compound and dispersing it at 40 to 100°C.

In the present invention, the "vinyl monomer containing a counterionic group" refers to an ionic group opposite to the ionic group contained in the polyester (a counterionic group when the ionic group contained in the polyester is an anionic group). means a vinyl monomer having a cationic group (or, when the ionic group contained in the polyester is a cationic group, the counterionic group is an anionic group). Such ionic groups are essential for shaping a stable aqueous dispersion of polyester.

The amount of counterionic groups in the polymer obtained by polymerizing vinyl polymerizable monomers is 0.8 to 260 in equivalent ratio to the amount of ionic groups in polyester.
, preferably in the range of 0.85 to 1°5. If the lower limit of this range is not reached, coalescence and growth of the fine particles will not occur, and even if the upper limit is exceeded, it will not only not contribute to the growth of the fine particles, but may also cause problems such as a decrease in the water resistance of the resin particles. .

As the cationic group-containing vinyl monomer, for example, 2
-Aminoethyl (meth)acrylate, 2-N,N-dimethylamineethyl (meth)acrylate, 2-N,N
-diethylaminoethyl (meth)acrylate, 2-N
, N-dipropylamino (meth)acrylate, 2-N
, t-butylaminoethyl (meth)acrylate, 2-
(4-morpholino)-ethyl (meth)acrylate, 2
-vinylpyridine, 4-vinylpyridine, aminostyrene, etc.

In addition, examples of anionic group-containing vinyl monomers include (meth)acrylic acid, itaconic acid, furotic acid, maleic acid,
Monomers containing carboxyl groups or their salts such as fumaric acid, styrenesulfonic acid, vinyltoluenesulfonic acid, vinylethylbenzenesulfonic acid, isopropenylbenzenesulfonic acid, 2-chlorostyrenesulfonic acid, 2-methyl-4-chlorostyrene Sulfonic acid groups, such as sulfonic acid, vinyloxybenzenesulfonic acid, vinylsulfonic acid, (meth)allylsulfonic acid, sulfoethyl or sulfopropyl ester of (meth)acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, or Monomers containing its salts Phosphoric acids such as azidophosphoxyethyl (meth)acrylate, andphosphoxy/propyl (meth)acrylate, 3-chloro-2-andphosphoxyprobyl methacrylate, bis(meth)acryloxyethyl phosphate, vinyl phosphate, etc. Examples include monomers containing groups or salts thereof.

In order to achieve the object of the present invention, a combination of an anionic group-containing polyester and a cationic group-containing vinyl monomer is more desirable. In addition, there is no problem in appropriately using known nonionic monomers.

There are no particular restrictions on the polymerization initiator used when polymerizing vinyl monomers, and examples include organic peroxides such as benzoyl peroxide and acetyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'- Azo compounds such as azobis(2,4-dimethylvaleronitrile), inorganic peroxides such as persulfates, hydrogen peroxide, permanganates, and the above inorganic peroxides and sulfuric acid, bisulfite, meth Examples include water-soluble redox initiators with reducing agents such as sulfite, hydrosulfite, thiosulfite, iron salts, and oxalic acid, but from a safety and general point of view, water-soluble redox initiators are recommended. Agents are preferred. The usage ratio of the compound initiator is approximately 0.1 to the vinyl monomer.
-3% by weight.

Although it is difficult to define the coalescence temperature unambiguously, polyester particles dispersed in an aqueous medium are coalesced and grown into a spherical shape as the vinyl monomer polymerizes.
1-, it is desirable to adopt a temperature condition higher than the glass transition point (Tg) of the polyester; under such temperature conditions, irregularly shaped particles are likely to be produced. By using a solvent and plasticity of the polyester in combination, the apparent glass transition point (or minimum film forming temperature) of the polyester can be lowered, and polymerization can be carried out under such temperature conditions.

There are no limitations on the type of solvent or plasticity, and they are appropriately selected from known solvents depending on the type of polyester as long as they do not inhibit polymerization.

Other polymerization conditions are carried out according to conventional methods, but the method of charging the vinyl monomer in advance into an aqueous dispersion of polyester fine particles and then dropping the polymerization initiator prevents rapid coalescence and aggregation of the polyester fine particles. This is preferable because there are no problems.

The obtained aqueous dispersion of polyester particles is taken out as a dry powder by a conventional method such as filtration, freeze drying, spray drying or the like.

Thus, the toner of the present invention is a substantially spherical particle with a ratio of the major axis to the minor axis of 0.7 or more, and has a diameter of 0.5D to 2.0D, where D is the average particle size. It is possible to industrially produce polyester resin particles having a relatively sharp distribution in which particles having a particle size falling within this range account for 70% or more of the total number on average.

The glass transition point of the polyester resin in the present invention is 4
The temperature is 0°C or higher. When the glass transition point is lower than this, there is a tendency to aggregate during handling or storage, which may cause problems in storage stability.

The softening point of the polyester resin in the present invention is 80 to 1
The temperature range is 50°C. Toners in which the softening temperature of the resin is kept lower than this tend to aggregate during handling or storage, and fluidity may deteriorate significantly, especially during long-term storage. If the softening point is higher than this, fixing performance will be impaired. Further, since it is necessary to heat the fixing roll to a high temperature, the material of the fixing roll and the material of the base material to be copied are limited.

One of the features of the electrophotographic toner of the present invention is that it contains a polyester resin "colored with a dye" as a main component. The dye used for coloring is a disperse dye, a basic dye, a cationic dye, or a dispersed cationic dye.

Further, when obtaining a black toner, carbon black or the like may be used in combination.

In the electrophotographic toner of the present invention, a charge control agent may be used to provide stable charge.

As a charge control agent that positively charges the toner through friction with carrier particles (carrier), for example, Cax Ba
Titanates such as carbonates, alkoxylated amines, polyamides such as nylon WML, phthalocyanine blue, pigments with positive zeta potential such as quinacridone, do, azo metal complex green, azine compounds, stearic acid-modified azines, etc. Compound,
Examples include azine pigments such as the oleic acid-modified azine compound nigrosine, and quaternary ammonium salt compounds.

Examples of the charge control agent that imparts a negative charge to the toner through friction with carrier particles (carrier) include pigments with a negative potential such as carbon black, halogenated phthalocyanine green, flavanstone yellow, and perylene red;
Examples include metal-containing azo compounds such as copper, zinc, lead, and iron.

In the toner of the present invention, a fluidity modifier such as fine alumina particles or fine silica particles may be added.

The amount added is not particularly limited, but from the viewpoint of imparting appropriate fluidity, it is preferably 0.00 to the toner.
The amount is about 0.01 to 5% by weight, more preferably about 0.1 to 2% by weight.

Toner used without being mixed with carrier particles (carrier): In the case of a component-based developer, the toner must have magnetism. In such cases, iron, cobalt, nickel, or alloys based on these, may be used as necessary.
Alternatively, oxides such as ferrite may be included.

The method of treating particles with the colorant, charge control agent, fluidity modifier, etc. described above is not particularly limited, and any known existing treatment method can be used. These may, for example, be dispersed in the particles, adsorbed onto the particles, coated on the particles, or implanted into the particle surfaces by, for example, a dry process such as mechanofusion.

The polyester resin used in the toner of the present invention exhibits good fixing properties because it does not cause fusion or aggregation at room temperature, and its viscosity quickly decreases during fixing.

The polyester resin used in the toner of the present invention has excellent color development in dyeing and also has excellent stability against dyes, and therefore exhibits good light emitting properties.

Since the toner in the present invention has excellent transparency, it not only produces a single color, but also has good color mixing properties when layered with other colors, so it has excellent reproducibility of intermediate colors. Furthermore, when an image is formed on a transparent film used in an overhead projector or the like, the image projected onto a screen also exhibits good color tone.

(Example) The present invention will be explained in more detail by referring to Examples below, but the present invention is not limited to these in any way. In addition, physical properties of resins and the like in Examples and Comparative Examples were measured by the following methods.

・Melting point, glass transition point Temperature increase rate 1
Measurement was performed at 0°C/min.

・Softening point Measured according to JIS K2351.

・Number average molecular weight (M atmospheric pressure method) It was measured using a molecular weight measuring device (newly manufactured by Hitachi Seisakusho).

...Measured using an automatic particle size distribution analyzer CAPA700 manufactured by Shima 7P Seisakusho.

・Sphericity Measure the major axis and minor axis from the projected image of the sphere measured by an optical microscope, and measure the sphericity by the ratio of the minor axis to the major axis. If it is 1.0, it is a perfect sphere, and if it is less than 1.0, it is spherical. It was determined to be a deformed ball.

[Example 1] In an autoclave equipped with a thermometer and a stirrer, 94 parts by weight of dimethyl terephthalate, 95 parts by weight of dimethyl isophthalate, 83 parts by weight of ethylene glycol,
120 parts by weight of neopentyl glycol and 1 g of tetraphthoxyl danate
The transesterification reaction was carried out by heating at ~230°C for 120 minutes. Next, 6.7 parts by weight of 5-sodium sulfoisophthalic acid was added, and the reaction was continued at 220 to 230°C for 60 minutes.
Furthermore, after raising the temperature to 250℃, the system pressure was 1 to 10W.
As a result of continuing the reaction for 60 minutes as dg, copolymerized polyester (A1) was obtained.

The molecular weight of the obtained copolymerized polyester (A1) is 270
0, sulfonic acid metal base is 118 equivalents 71,000,000
It was g. The amount of sulfonic acid metal base was determined by measuring the sulfur concentration in the copolyester. Further, as a result of NMR analysis, the composition of the copolymerized polyester (A1) was found to be as follows: 48.5% terephthalic acid, 49.0% isophthalic acid, 2.5J% 5-sodium sulfoisophthalic acid, and 2.5J% 5-sodium sulfoisophthalic acid as the alcohol component. Glycol: 6■, 0-% neopentyl glycol: 39.07%.

In a four-necked 1-liter separable flask equipped with a thermometer, condenser, and stirring blade, 34 parts by weight of the obtained copolymerized polyester (AI) and 10 parts by weight of butyl cellosolve were dissolved at 110°C. Aqueous dispersion of copolyester (Bl) by adding 56 overlapping parts of water at ℃
I got it.

In a four-necked 1-liter separable flask equipped with a thermometer, condenser, and stirring blade, 834 parts by weight of copolyester aqueous dispersion (Bl), 35 parts by weight of deionized water,
Then, 5.6 parts by weight of dimethylaminoethyl methacrylate was added, and the temperature was raised to 70°C. Next, 100 parts by weight of an aqueous solution containing 0.2 parts by weight of ammonium persulfate was added dropwise over 40 minutes, and the reaction was continued at 70° C. for an additional 60 minutes. As a result, the submicron-order particle diameter copolymer present in the copolyester aqueous dispersion grew to a particle size in the range of 0.5D to 2.0D, where D is the average particle diameter of 8.7-1. Polyester particles (C1) having a particle size of 92% (number) were obtained.

Adding water to the obtained polyester particles (C1)
An aqueous dispersion (Dl) of polyester particles having a weight of 0% and 1% was obtained.

Sumitomo Chemical Disperse Dye Sumikalon Yellow 5E-5G (
C, 1, Disperse Yellow 5) 10 parts by weight of water 1
00 parts by weight of polyester particle dispersion (DI
) 500 parts by weight, heated to 50°C while stirring,
It was held for 60 minutes.

Thereafter, it was cooled, filtered, washed, and dried in vacuum to obtain a yellow toner (EIY).

Similarly, Sumikaron Red E-FB, a disperse dye manufactured by Jumin Chemical.
L (C, 1, Disperse Red 60), Sumikalon Blue E-FBL (C, I.

A magenta toner (EIM) and a cyan toner (E I C) were obtained from the polyester particle dispersion (Dl) using Disperse Blue 56).

5 parts by weight of each of the obtained colored toners were mixed with 95 parts by weight of a carrier (spherical reduced iron powder with an average particle size of 80III) to obtain a two-component electrophotographic developer. The charge amount of the toner after mixing with the carrier was (EIY) −75 μC/g (EIM) −88 μC/g (Etc) −80 μC7g. Using these developers, 5,000 copies were continuously made on paper using an electrophotographic color copying machine using amorphous silicon as a photoreceptor. The obtained copy showed a clear and good image without fogging or fading.

Using this developer, copies were similarly made onto a transparent film for an Overherad projector. The obtained copy had excellent spectral transmission characteristics, and the image projected onto the screen by the Overherad projector showed a clear color tone without turbidity.

Further, no particular problems were observed in the humidity dependence of charging properties, flow properties, insulation properties, etc., as well as fixing properties, sharp melt properties, offset resistance, etc.

[Example 2] 94 parts by weight of dimethyl terephthalate, 95 parts by weight of dimethyl isophthalate, ethylene glycol soxig, 100 parts by weight of neopentyl glycol
Parts by weight, and 0.1 weight 11 of tetraphthoxypro9nate
ti5-sodium sulfoisophthalic acid 1
．． A copolymerized polyester (A2) was obtained in the same manner as in Example 1 using a double placement section. The molecular weight of the obtained copolymerized polyester (A2) was 2,800, and the amount of sulfonic acid metal base was 24 equivalents/1,000,000 g. In addition, the composition of the copolymerized polyester (A2) was determined by NMR analysis: as an acid component, terephthalic acid: 43.5% isophthalic acid: 50.0EQ% 5-sodium sulfoisophthalic acid: 0.51oQ%; as an alcohol component: ethylene glycol It was 53.0-% neopentyl glycol.

Next, a copolymerized polyester aqueous dispersion (B2) was obtained in the same manner as in Example 1, and polyester particles (C2) were obtained in the same manner. The average particle size of the obtained polyester particles (C2) was 7.

The coverage ratio (number of particles) of particles having particle diameters in the range of 5-5 and 0.5D to 2.0D was 88%.

The obtained polyester diameter particles (C2) were made into a polyester particle dispersion (B2) in the same manner as in Example 1,
Furthermore, colored toner (E) was dyed in the same manner as in Example 1.
2Y)(E2R)(E2B) was obtained.

5 parts by weight of each of the obtained colored toners were mixed with 95 parts by weight of a carrier (spherical reduced iron powder with an average particle size of 80/All) to obtain a two-component electrophotographic developer. The charge amount of the toner after mixing with the carrier was (E2Y) −88 μC7g (E2M) −75 μC7g (E2G) −89 μC7g. Using these developers, 5,000 copies were continuously made on paper using an electrophotographic color copying machine using an amorphous silicon photoreceptor as in Example 1. The resulting copy was free from fog and fading, and showed a clear and good image.

Using this developer, copies were made in the same manner onto transparent film E for Overherad projector. The obtained copy had excellent spectral transmission characteristics, and the image projected onto the screen by the Overherad projector showed a clear color tone without turbidity.

Further, no particular problems were observed in the humidity dependence of charging properties, flow properties, insulation properties, etc., as well as fixing properties, sharp melt properties, anti-offset properties, etc.

[Example 3] Cationic dye Maxilon Yellow 2 manufactured by Ciba Geigy
RL (C.1. Paysic Yellow 19), Maxilon Red GRL (C.1. Paysic Red-4
8) 10 parts by weight of each of Maxilon Blue GRL (C.1. Paysic Blue 41) were dissolved in 100 parts by weight of water and added to 500 parts by weight of the polyester particle aqueous dispersion CD2) obtained in Example 2. The mixture was heated to 50° C. with stirring and held for 60 minutes. Then cooling,
Filter, wash, dry in vacuum, and use colored toner (E3Y).
) (E3R) (E3B) were obtained.

5 parts by weight of each of the obtained colored toners, 95 parts by weight of carrier (spherical reduced iron powder with an average particle size of 80 ps),! : Mixed to obtain a two-component electrophotographic developer. The charge amount of the toner after carrier mixing was (E3Y) −82 μC/g (E3M) −76 μC/g (E3C) −84 μC/g. Using these developers, 5,000 copies were continuously made on paper using an electrophotographic color copying machine using amorphous silicon as a photoreceptor in the same manner as in Example 1. The resulting copy was free from fog and fading, and showed a clear and good image.

Using this developer, copies were similarly made onto a transparent film for an Overherad projector. The obtained copy had excellent spectral transmission characteristics, and the image projected onto the screen by the over-nod projector showed a clear color tone without turbidity.

Furthermore, no particular problems were observed in the humidity dependence of charging properties, flow properties, and insulation properties, as well as in fixing properties, sharp melt properties, offset resistance, and the like.

[Comparative Example 1] Copolymerized polyester (AI) 9 obtained in Example 1
Sumikalon Yellow 5E-50 (C, 1, Disperse Yellow 5), a disperse dye manufactured by Sumika Chemical Co., Ltd. used in Example 1 and Sumikalon Red E-FBL (C, 1, Disperse Yellow 5), a disperse dye manufactured by Sumika Chemical Co., Ltd.・Red 6
0), Sumikalon Blue E-FBL (C,!, Disperse Blue 56) and 10 parts H are each premixed in a ball mill, melted and mixed in a roll mill, pulverized and classified in a pulverizer, and averaged. Colored toners (E4Y) (E4M) (E4C) having a particle size of 12/jj were obtained.

5 parts by weight of each of the obtained colored toners were mixed with 95 parts by weight of a carrier (spherical reduced iron powder with an average particle size of 80 tua) in the same manner as in the example to obtain a two-component electrophotographic developer. The charge amount of the toner after mixing with the carrier was (E1\) -45 μC/g (EIM) -42 μC/g (Etc) -39 μC/g. As in Example 1, using these developers, 5,000 copies were continuously made on paper using an electrophotographic color copying machine using amorphous silicon as a photoreceptor. Although no fogging or fading was observed in the obtained copies, the color tone was low and the reproducibility of intermediate colors was also poor.

Also, using this developer, copies were made on a transparent film-L for an Overherad projector. The copies obtained likewise exhibited a low color tone. These are the results of discoloration of the disperse dye during dispersion of the dye in the polyester resin.

[Comparative Example 2] Copolymerized polyester (AI) 9 obtained in Example 1
0 parts by weight, an azo yellow pigment, a rhodamine red pigment,
10 crushed portions of phthalocyanine-based youth pigment are premixed in a ball mill, melted and mixed in a roll mill, and crushed and classified in a fine grinder to obtain a colored toner (with an average particle size of LIP).
E5Y) (E5M) (E5C) was obtained.

5 parts by weight of each of the obtained colored toners were mixed with 1 part of carrier (spherical reduced iron powder having an average particle size of 80 mm) in the same manner as in the example to obtain a two-component electrophotographic developer. Band of toner after mixing with carrier';! Ell was (EIY) -38μC/g (ELM) -41μC/g (Etc) -34μC/g. As in Example 1, using these developers, 5,000 copies were continuously made on paper using an electrophotographic color copying machine using amorphous silicon as a photoreceptor. The obtained copies showed good images without fogging or fading. However, when this developer was used to make a copy on a transparent film for an Overherad projector, the resulting copy exhibited a clear color tone as long as it was observed by reflected light. The image projected onto the screen by the Overherad projector, that is, the image observed using transmitted light, had a dim (muddy) color tone with significantly poor clarity.

(Effects of the Invention) As described above, the toner according to the present invention has excellent humidity dependence such as charging properties, fluidity properties, and insulation properties, as well as fixing properties,
It has excellent sharp melt properties, anti-offset properties, etc., and also exhibits good spectral transmission characteristics, so it provides images with clear and good color tone, especially in reproduced images observed by transmitted light from an overhead projector, etc. .

Claims (2)

[Claims] (1) Softening point is 80-150℃, glass transition point is 40℃
Contains the resin (A) whose main component is the above polyester, and has an average particle size of 1 to 30 μm, and has a particle size in the range of 0.5D to 2.0D, where D is the average particle size. An electrophotographic toner characterized in that particles of 70% or more are present on average. (2) The electrophotographic toner according to claim (1), which is dyed with a dye.