JPH1010777A - Binder resin and toner for toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder resin from which a toner excellent in image stability can be obtained without impairing the fixability, blocking resistance and non-offset property as a toner. SOLUTION: An acid component containing a dicarboxylic acid as a main component,
A diol component containing an aromatic diol and / or an aliphatic diol as a main component, and having a work function of 3.4.
A polyester resin in which the compound consisting of a metal element having eV or more is 300 ppm or less based on all acid components, having a glass transition temperature of 50 to 75 ° C and a softening temperature of 80 to
A binder resin for toner having an acid value of not more than 25 mgKOH / g at 170 ° C. and a toner containing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin useful as a binder resin for a dry toner used for developing an electrostatic image or a magnetic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like. . More specifically, the present invention relates to a binder resin for a toner having excellent fixing properties, blocking resistance, non-offset properties, and image stability.

[0002]

2. Description of the Related Art In a method for obtaining a permanent visual image from an electrostatic image, a method is used in which an electrostatic image formed on a photoconductive photoreceptor or an electrostatic recording medium is developed by a toner previously charged by friction. Is established. For a magnetic latent image,
After the latent image on the magnetic drum is developed with toner containing a magnetic material, it is fixed. Fixing is performed by directly fusing a toner image obtained by development on a photoconductive photoreceptor or an electrostatic recording medium, or by transferring a toner image onto paper or a film and then fusing it on a transfer sheet. This is done by:
The fusing of the toner image is performed by contact with solvent vapor, pressurization and heating. There are two types of heating method: non-contact heating method using an electric oven and pressure heating method using a pressure roller. Recently, the latter is mainly used.

[0003] Toner used in the dry development system includes 1
There are two-component toners and two-component toners. The two-component toner is first melt-kneaded with a binder resin, a colorant, a charge control agent and other necessary additives and sufficiently dispersed,
It is manufactured by coarsely pulverizing, then finely pulverizing and classifying into a predetermined particle size range. The one-component toner is similarly manufactured by adding magnetic powder in addition to the components of the two-component toner. In particular, the binder resin is the main component in the compounding of the toner, and thus controls most of the performance required for the toner. For this reason, the binder resin for the toner is required to have a dispersibility of the colorant in the melt-kneading step in the production of the toner, a pulverizability in the pulverization step, and the like. Versatile performance such as performance and charging stability is required.

[0004]

Recently, there has been an increasing application to mass demand applications such as continuous printing for a long time, and there is a need for a toner capable of obtaining a stable image even for a long time printing. It is becoming increasingly important that a toner can maintain a stable charge amount. In response to such demands, conventionally, a method of using a fixed amount of a charge control agent to secure a charge amount required for a developing system has been generally performed. However, in the adjustment of the charge amount by such a charge control agent, even if a large amount of the charge control agent is used, the obtained charge amount and its stability are limited, and particularly, a stable charge amount is maintained for a long time. It was difficult. In addition, the use amount and type of such charge control agents are becoming limited from the viewpoint of environmental problems and the like.

Generally, epoxy resins, polyester resins, polystyrene resins, methacrylic resins, and the like are used as binder resins for toners. The charge amount of the toner can be increased by adjusting the monomer composition and functional groups. Attempts have been made to improve the charging stability, but no satisfactory charging characteristics have yet been obtained. Among these binder resins, in particular, polyester resins have been attracting attention as being capable of obtaining toner having a high charge amount, and a metal catalyst used at the time of polymerization of the polyester resin is one factor for increasing the charge amount of the toner. It has been. However, the metal catalyst used at the time of polymerization of the polyester resin interacts with additives of the toner and the like, so that satisfactory charging characteristics could not be obtained. Accordingly, an object of the present invention is to provide a polyester resin toner as a toner binder resin having excellent image stability without impairing the fixability, blocking resistance, and non-offset property of the toner. .

[0006]

That is, the binder resin for toner of the present invention comprises an acid component containing dicarboxylic acid as a main component and a diol component containing aromatic diol and / or aliphatic diol as a main component. A polyester resin in which the compound comprising a metal element having a work function of 3.4 eV or more is 300 ppm or less based on the total acid components, the glass transition temperature is 50 to 75 ° C, the softening temperature is 80 to 170 ° C, The acid value is 25 mgKOH / g or less. Also, according to the present invention,
It is characterized by containing a binder resin containing such a polyester resin as a main component and a coloring agent.

According to the present invention, a metal compound comprising a specific metal element capable of increasing the charge amount of a toner is used as a polymerization catalyst for polymerizing a polyester resin as a binder resin for a toner. By using it in a range where there is no interaction with additives and the like, a binder resin for a toner containing a specific metal compound in a specific range is produced, and stable charging as a toner is performed over a long period of time. Thus, a toner having excellent image stability can be obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyester resin as a binder resin for a toner of the present invention has a work function (φ) of 3.4.
A metal compound comprising a metal element having eV or more is contained in a range of 300 ppm or less based on all acid components. Such a metal compound is mainly caused by a polymerization catalyst when polymerizing the polyester resin, and by using a specific type of polymerization catalyst in a specific usage amount, the polyester resin of the present invention is obtained. be able to.

In the present invention, the work function (φ) is the minimum energy required to extract electrons in a solid bound similarly to electrons in atoms from a solid through a surface into a vacuum, A value measured by a photoelectron emission method for measuring electrons emitted when a metal element is irradiated with light in a high vacuum. Such a work function (φ) is 3.4 eV
The charge amount of the toner can be increased by incorporating a metal compound composed of the above metal elements into the polyester resin. Preferably, the work function (φ)
Is a metal compound comprising a metal element of 3.5 eV or more.

Examples of the metal element having a work function (φ) of 3.4 eV or more include aluminum, cobalt, chromium, germanium, molybdenum, nickel, antimony, selenium, tin, tellurium, titanium, panadium, zinc, and the like. Preferred are germanium, antimony, tin, titanium, and zinc, and particularly preferred are germanium, antimony, tin, and titanium, which are elements of Group IV or Group V in the periodic table with 4 or 5 periods. Examples of the metal compound composed of such a metal element include manganese acetate tetrahydrate and cobalt acetate 1
Hydrate, zinc acetate dihydrate, germanium dioxide, antimony trioxide, titanium tetrabutoxide, titanium tetramethoxide, titanium tetraethoxide, titanium tetra2
-Ethylhexoxide, dibutyltin oxide, dibutyltin acetoxide, dibutyltin dimethoxide, dibutyltin diurarate, dibutyltin sulfide, dibutyltin maleate, and the like, and any of them can be used as a polymerization catalyst for polyester resins, alone or Two or more can be used in combination. Among them, germanium dioxide, antimony trioxide, dibutyltin oxide, and titanium tetraethoxide are preferable, and antimony trioxide and titanium tetraethoxide are more preferable.

It is important that these metal compounds are contained in the polyester resin in a range of 300 ppm or less, preferably in a range of 200 ppm or less, more preferably in a range of 100 ppm or less. When this content is 30
If the content exceeds 0 ppm, an interaction occurs such as reaction with an additive of the toner or cancellation of electric charges, and the charge stability of the toner decreases.

The dicarboxylic acids constituting the polyester resin of the present invention include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and aliphatic acids such as phthalic acid, sebacic acid, isodecyl succinic acid, maleic acid, fumaric acid and adipic acid. Examples include dicarboxylic acids and their lower alkyl esters or acid anhydrides. Examples of the lower alkyl esters of these dicarboxylic acids include monomethyl ester, monoethyl ester, dimethyl ester, diethyl ester and the like. Among them, terephthalic acid, isophthalic acid, adipic acid and lower alkyl esters thereof are preferred. These dicarboxylic acids can be used alone or in combination of two or more. In the present invention, the dicarboxylic acid adjusts the glass transition temperature of the polyester resin to improve the blocking resistance and the fixing property of the toner, and is preferably contained in the range of 70 to 100 mol% in all the acid components. , More preferably 90
-100 mol%, more preferably 95-100 mol%.

In particular, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid increase the glass transition temperature of the polyester resin and contribute to the improvement of the blocking resistance of the toner.
Due to its hydrophobicity, it is also effective in improving the moisture resistance of the toner. Therefore, the amount of the aromatic dicarboxylic acid needs to be 50 mol% or more, preferably 60 mol% or more, based on all the acid components. Among them, terephthalic acid-based ones are effective in increasing the glass transition temperature of the binder resin, and isophthalic acid-based ones are effective in increasing the reactivity, so that it is preferable to use them by changing the use balance depending on the purpose. . On the other hand, an aliphatic dicarboxylic acid such as adipic acid greatly affects the fixing property and the blocking resistance of the toner. Therefore, it is necessary to use these properties in consideration of these properties. Is preferably used.

In the present invention, as a component constituting the polyester resin, a trivalent or higher polycarboxylic acid or a trivalent or higher polyhydric alcohol can be used as necessary. Trivalent or higher polycarboxylic acid or 3
The polyhydric alcohol having a valency or higher promotes the reaction of the polyester resin and adjusts the molecular weight and the molecular weight distribution, and can improve the fusing property and filming property of the toner. As a trivalent or higher polycarboxylic acid,
Trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid,
1,2,5-hexanetricarboxylic acid, 1,2,7,8
-Octanetetracarboxylic acid and acid anhydrides thereof. Among them, trimellitic acid and trimellitic anhydride are preferred. Examples of the trihydric or higher polyhydric alcohol include sorbitol, 1,2,3,6-hexanetetralol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, and 1,2,4-butane. Triol, 1,2,5-pentatriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol,
Trimethylolethane, trimethylolpropane, 1,
3,5-trihydroxymethylbenzene and the like. Among them, trimellitic acid and its acid anhydride, pentaerythritol, and trimethylolpropane are preferred. These tri- or higher polycarboxylic acids or tri- or higher polyhydric alcohols can be used alone or in combination of two or more.

In the present invention, the amount of the trivalent or higher polyhydric carboxylic acid and / or the trivalent or higher polyhydric alcohol used may be selected in consideration of the degree of polymerization or the balance between the molecular weight and the glass transition temperature. Although it can be used, it is preferably used in a range of 30 mol% or less, more preferably in a range of 27 mol% or less based on all acid components. this is,
If the content of the trivalent or higher polycarboxylic acid and / or the trivalent or higher polyhydric alcohol exceeds 30 mol%, the melt viscosity of the polyester resin becomes high, and the fixing property of the toner tends to decrease.

Further, the aromatic diol constituting the polyester resin of the present invention increases the glass transition temperature of the polyester resin, imparts resin strength, and reduces low molecular weight components of the polyester resin. And a component for controlling the reactivity of the resin, and an aromatic diol represented by the general formula (1) can be used.

[0017]

Embedded image

(In the formula, R1 is an alkylene group having 3 or less carbon atoms, and m and n are natural numbers.) As the aromatic diol, for example, polyoxyethylene- (2.0) -2,2- Bis (4-hydroxyphenyl) propane, polyoxyethylene- (2.3) -2,
2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (2.8) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (3.
0) bisphenol A derivatives to which ethylene oxide is added, such as 2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, Polyoxypropylene- (2.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.
8) Bisphenol A derivatives to which propylene oxide is added such as -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene- (3.0) -2,2-bis (4-hydroxyphenyl) propane These can be used alone or in combination of two or more.

In particular, bisphenol A derivatives to which propylene oxide has been added are preferred in order to increase the glass low temperature of the polyester resin and to impart resin strength. In order to reduce the low molecular weight components of the polyester resin, ethylene oxide is preferred. An added bisphenol A derivative is preferred. Among them, polyoxypropylene (n) -2,2-bis (4-hydroxyphenyl) propane satisfying 2.1 ≦ n ≦ 2.5, and 2.0 ≦ n ≦ 3.
Polyoxyethylene- (n) -2,2-bis (4-hydroxyphenyl) propane, which is 0, is preferred.

Since these aromatic diols are liable to undergo thermal decomposition at high temperatures, when used in combination with a dicarboxylic acid requiring high reactivity, 20 to 110 parts by weight of the total acid component is used.
It is preferably used in the range of mol%, more preferably in the range of 25 to 105 mol%. This is because when the aromatic diol is less than 20 mol%, the glass transition temperature of the polyester resin tends to decrease, and the blocking resistance of the toner tends to decrease. On the other hand, when the amount of the aromatic diol exceeds 110 mol%, the reactivity is remarkably reduced, and the reaction does not proceed to a desired degree of polymerization.

The aliphatic diol constituting the polyester resin of the present invention improves the polycondensation reaction rate of the resin. For example, ethylene glycol, neopentyl glycol, propylene glycol, butanediol, polyethylene glycol, 1,2, -Propanediol,
Examples thereof include 1,4-butanediol, diethylene glycol, triethylene glycol, 1,4-cyclohexanedimethanol, and hydrogenated bisphenol A, and these can be used alone or in combination of two or more. Among them, ethylene glycol, neopentyl glycol, and butanediol are preferable from the viewpoint of fixing property as a toner. Aliphatic diols are 5 to 110 relative to the total acid component.
It is preferably used in the range of mol%, more preferably in the range of 10 to 105 mol%. When the aliphatic diol is less than 5 mol%, the reactivity tends to be remarkably reduced and the reaction does not proceed to a desired degree of polymerization.
If it exceeds 10 mol%, the glass transition temperature and the resin strength of the polyester resin are liable to decrease, and the blocking resistance of the toner tends to decrease.

The polyester resin for a toner of the present invention having the above-described structure must have a glass transition temperature of 50 to 75 ° C., a softening temperature of 80 to 170 ° C., and an acid value of 25 mg KOH / g or less. This is because the glass transition temperature is 5
If the temperature is lower than 0 ° C., the blocking resistance as a toner is inferior,
Conversely, when the temperature exceeds 75 ° C., the blocking resistance is good, but the fixing performance as a toner is remarkably reduced, and the temperature is preferably in the range of 52 to 73 ° C. When the softening temperature is lower than 80 ° C., the fixing performance as a toner is improved, but the cohesive force of the polyester resin is extremely reduced and sufficient non-offset property cannot be obtained.
When the temperature exceeds 70 ° C., the non-offset property is improved, but the fixing performance as a toner is extremely lowered, and the temperature is preferably in the range of 85 to 165 ° C. Furthermore, the acid value is 2m
If the amount exceeds gKOH / g, the charge amount of the toner tends to change depending on the environment, and the charge stability is reduced. The amount is preferably 20 mgKOH / g or less.

The polyester resin of the present invention has a peak molecular weight in the range of 1500 to 20,000 in a molecular weight distribution determined by gel permeation chromatography, a weight average molecular weight (Mw) of 60,000 or more, and a weight average molecular weight of The ratio (Mw / Mn) of (Mw) to the number average molecular weight (Mn) is preferably in the range of 20 or more. If the molecular weight of the peak in the molecular weight distribution by gel permeation chromatography is less than 1500, the glass transition temperature of the polyester resin tends to decrease, and the blocking resistance as a toner tends to decrease. If it exceeds 300, the fixability as a toner tends to be impaired, and
00 range. Further, the weight average molecular weight (Mw) is 6
If the ratio is less than 0000 or Mw / Mn is less than 20, the non-offset property of the toner tends to decrease.

Further, when the polyester resin of the present invention is used as a binder resin for a full-color toner, the weight average molecular weight (Mw) is 2,000 to 60,000.
The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably in the range of 1.5 to 20. This means that the molecular weight of the peak in the molecular weight distribution by gel permeation chromatography is 150.
If it is less than 0, the glass transition temperature of the polyester resin tends to decrease, and the blocking resistance as a toner tends to decrease. If it exceeds 20,000, the fixability as a toner tends to be impaired. ~ 1
The range is 5000. Also, weight average molecular weight (Mw)
If it is less than 2,000, the glass transition temperature of the polyester resin tends to decrease and the blocking resistance as a toner tends to decrease. Conversely, if it exceeds 60,000, the viscosity of the polyester resin increases and the fixability as a toner decreases. And preferably in the range of 3000-58,000. Further, when Mw / Mn is less than 1.5, the blocking resistance as a toner tends to decrease, and when it exceeds 20, the color developability and fixability as a toner tend to decrease.

In the production of the polyester resin of the present invention, the above-mentioned polymerization components are charged into a reactor, and heated to raise the temperature.
Perform an esterification or transesterification reaction. At this time, a metal compound composed of a metal element having a work function (φ) of 3.4 eV or more as described above is used as a polymerization catalyst. Next, water or alcohol generated by the reaction is removed according to a conventional method. Thereafter, a polymerization reaction is subsequently performed. At this time, polycondensation is performed while distilling and removing the diol component under a vacuum of 150 mmHg or less. Also in this polycondensation, a metal compound composed of a metal element having a work function (φ) of 3.4 eV or more as described above can be used as a polymerization catalyst, if necessary. On this occasion,
It is necessary that the total amount of the polymerization catalyst used is in the range of 300 ppm or less. This is because when the amount of the polymerization catalyst exceeds 300 ppm, the content of the metal compound contained in the polyester resin increases, and the interaction such as the reaction with the additive of the toner or the cancellation of the charge occurs. This causes the charging stability of the toner to decrease.

In the method for producing a polyester resin of the present invention, when condensation polymerization is carried out after the esterification reaction, the reaction temperature of the condensation polymerization at the time when the polymerization is finally completed is lower than the reaction temperature of the esterification. It is also preferable to set the polymerization conditions so as to lower the temperature by 10 ° C. or more. In the case where condensation polymerization is carried out after the transesterification reaction, polymerization conditions such that the reaction temperature of the condensation polymerization at the time when the polymerization is finally completed is 5 ° C. or more lower than the reaction temperature of the transesterification are used. Is preferred. Further, when performing the condensation polymerization reaction while cooling after the esterification or transesterification reaction is completed, the cooling time to the target condensation polymerization reaction temperature is set to 3 hours.
It is preferably within an hour, more preferably 2.
Within 5 hours. If this cooling time exceeds 3 hours,
This is because the reaction rate of the polycondensation increases, and the reaction tends to proceed too much, so that it is difficult to control the physical properties of the obtained polyester resin.

The toner of the present invention contains the above polyester resin as a main component of the binder resin, and includes a styrene polymer, a styrene-acrylic copolymer, a styrene-butadiene copolymer, and an epoxy resin. A binder resin can be used in combination with another resin such as a system resin. Further, the toner of the present invention contains not less than 60% by weight of the binder resin as described above, a coloring agent such as an inorganic pigment, a chromatic dye and an organic pigment, a wax such as a polyolefin wax, Teflon, and zinc stearate. A lubricant such as polyvinylidene fluoride, a negatively or positively chargeable charge control agent, a release agent, a magnetic material, a flow modifier and the like are blended as necessary, and the resulting blend is, for example,
It can be manufactured by melt-kneading using a hot roll, a kneader, an extruder or the like, and then pulverizing and classifying using a jet mill, an air classifier or the like to obtain a predetermined average particle size.

As the colorant that can be used in the toner of the present invention, known colorants can be used, for example, carbon black, iron black, nigrosine, benzene yellow,
Quinacdrine, rhodamine B, phthalocyanine blue and the like. As the charge control agent, a known charge control agent having a negative charge or a positive charge can be used. For example, Al, Ba, Ca, Cd, Co, Cu, Fe, H
g, Mg, Mn, Ni, Pb, Sn, Sr, Zn, etc.
Organic metal compounds such as organic salts and complexes containing a metal having a valency or higher can be given. As the organometallic compound, a carboxylate, an alkoxylate, an organometallic complex of the above metal,
Chelate compounds and the like. These charge control agents are
It can be used in the range of about 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

[0029]

The present invention will be described below in detail with reference to examples. The performance evaluation in Examples and Comparative Examples was performed using the following method. Glass transition temperature (° C) Using a differential scanning calorimeter manufactured by Shimadzu Corporation, heating rate 5 ° C /
The contact point between the tangent of the endothermic curve near the glass transition temperature measured in minutes and the baseline was taken as the glass transition temperature. Softening temperature (° C) Using a flow tester (CFT-500) manufactured by Shimadzu Corporation, nozzle 1.0 mmφ × 10 mmL, load 30 kg
f, Measured at a constant heating rate of 3 ° C./min, and the temperature at which half of the 1.0 g sample flowed out was taken as the softening temperature (° C.).

Composition analysis The resin was hydrolyzed with hydrazine and quantified by liquid gas chromatography. Molecular weight distribution, weight average molecular weight, number average molecular weight
The measurement was carried out using gel permeation chromatography (HCL-8200) manufactured by Tosoh Corporation. The acid value was measured by a titration method using a KOH solution. Composition analysis
The resin was hydrolyzed with hydrazine and quantified by liquid chromatography.

The fixability (1) full-color toner temperature can be changed freely by using the full-color copying machine having a blade, the fixability to paper upon printing by the printing speed of 10 sheets / min, the following Evaluation was based on criteria. ：: Fixable at 120 ° C. or less. ：: Fixing is possible at 121 to 135 ° C. X: Fixable at 135 ° C or higher.

(2) The temperature of the toner other than full color can be freely changed, and the roller speed can be adjusted to 1
The minimum temperature (minimum fixing temperature) at which the toner did not transfer to the fixing roller was measured using a copying machine set to 50 mm / sec, and evaluated according to the following criteria. A: The minimum fixing temperature is 140 ° C. or lower. ：: The minimum fixing temperature is 141 to 150 ° C. Δ: Minimum fixing temperature is 151 to 160 ° C. X: The minimum fixing temperature exceeds 160 ° C.

The non-offset temperature can be freely changed, and the roller speed can be adjusted to 1
Using a copier set at 50 mm / sec, the temperature at which the toner transferred to the fixing roller was measured and evaluated according to the following criteria. A: 220 ° C. or higher. ：: 200 to 219 ° C. Δ: 180 to 199 ° C. X: It is less than 180 degreeC.

5 g of toner is placed in a 50 ml glass sample bottle having blocking resistance .
After standing in a constant temperature bath at 50 ° C. for 24 hours, the mixture was cooled to room temperature, the degree of aggregation was observed, and evaluated according to the following criteria. In the case of evaluations A and B, it was determined that the blocking resistance was good. A: The toner is dispersed only by turning the sample bottle upside down. ：: The toner is dispersed when the sample bottle is turned upside down and hit twice or three times. ×: The toner is dispersed when the sample bottle is inverted and hit four or more times.

The image stability temperature can be freely changed and the roller speed can be adjusted to 1
10,000 copies were printed using a copying machine set at 50 mm / sec, and the initial charge amount and image density and the final charge amount and image density were evaluated based on the following criteria. A: The charge amount and image density are stable. ：: The charge amount slightly changed, but the image density did not change much. Δ: There is a change in the charge amount and image density, but it is within the range that can be improved by the additive. X: The change in the charge amount and image density is remarkable.

Examples 1-4 Each raw material having the composition shown in Table 1 was charged into a reaction vessel equipped with a distillation column. Further, antimony trioxide (work function of antimony (φ) = 4.31 eV) was added as a polymerization catalyst in an amount shown in Table 1 with respect to all the acid components, and stirring speed was 12
At 0 rpm, the temperature in the reaction system was raised to 265 ° C., and the esterification reaction was carried out for about 8 hours after water began to distill from the reaction system under normal pressure, and water distilling was stopped. At that time, the esterification reaction was terminated. Thereafter, the temperature in the reaction system was cooled to 250 ° C. (cooled to 230 ° C. in Example 4), and the degree of vacuum in the reaction system was further reduced to about 1.0 mmHg over about 40 minutes. The condensation reaction was performed while distilling out the diol component. In the condensation reaction, the degree of vacuum was increased along with the increase in the viscosity of the reaction system, and when the desired softening temperature was reached, the pressure of the reaction system was returned to normal pressure to obtain a transparent polyester resin. The results of the composition analysis of the obtained resin are shown in Table 1, and the measurement results of glass transition temperature, softening temperature, acid value, molecular weight distribution, weight average molecular weight (Mw) and weight average molecular weight (Mw) / number average molecular weight (Mn) are shown. Are shown in Table 2.

92 parts by weight of the obtained polyester resin,
5 parts by weight of carbon black (# 44, manufactured by Mitsubishi Chemical Corporation), 2 parts by weight of wax (660P, manufactured by Sanyo Kasei) and 1 part by weight of a charge control agent (S-34, manufactured by Orient) were mixed for 30 minutes using a mixer. Thereafter, using an internal mixer, melt kneading was performed for 30 minutes while setting the internal temperature to the softening temperature of the polyester resin. Next, the cooled toner mass was finely pulverized using a jet mill fine pulverizer, and the particle size of the toner particles was adjusted by a classifier to obtain a toner having an average particle size of 7 μm. The fixing property, non-offset property, blocking resistance and image stability of the obtained toner were evaluated, and the results are shown in Table 2.

Examples 5 to 9 Using the raw materials having the composition shown in Table 1, antimony trioxide (work function of antimony (φ) = 4.31 eV), tetratitanium oxide (work function of titanium) (Φ) = 4.2 eV) and under the same conditions as in Example 1 except that dibutyltin oxide (the work function of tin (φ) = 3.62 eV) was added to all the acid components in the amounts shown in Table 1. Polymerization was performed to obtain a transparent polyester resin. The results of the composition analysis of the obtained resin are shown in Table 1, and the measurement results of glass transition temperature, softening temperature, acid value, molecular weight distribution, weight average molecular weight (Mw) and weight average molecular weight (Mw) / number average molecular weight (Mn) are shown. Are shown in Table 2. Using the obtained polyester resin, a toner was formed under the same conditions as in Example 1,
The fixing property, non-offset property, blocking resistance and image stability of the obtained toner were evaluated, and the results are shown in Table 2.
It was shown to.

Examples 10 to 13 Each raw material having the composition shown in Table 1 was charged into a reaction vessel equipped with a distillation column. Further, as a polymerization catalyst, antimony trioxide (work function of antimony (φ) = 4.31 eV), tetratitanium oxide (work function of titanium (φ) =
4.2 eV) was added in the amount shown in Table 1 with respect to all the acid components, the stirring speed was kept at 120 rpm, the temperature in the reaction system was raised to 265 ° C., and water was removed from the reaction system under normal pressure. The esterification reaction was performed for about 8 hours after the distillation started, and the esterification reaction was terminated when the distillation of water stopped. Thereafter, the temperature in the reaction system was cooled to 250 ° C. (cooled to 230 ° C. in Example 4), and the degree of vacuum in the reaction system was further reduced to about 1.0 mmHg in about 40 minutes. The condensation reaction was performed while distilling out the diol component. Thereafter, when the desired softening temperature was reached, the pressure of the reaction system was returned to normal pressure, and a transparent polyester resin was obtained. The results of the composition analysis of the obtained resin are shown in Table 1, and the measurement results of glass transition temperature, softening temperature, acid value, molecular weight distribution, weight average molecular weight (Mw) and weight average molecular weight (Mw) / number average molecular weight (Mn) are shown. Are shown in Table 2. Using 94 parts by weight of the obtained polyester resin, 2 parts by weight of phthalodianine blue, and 5 parts by weight of a charge control agent, a full-color cyan toner was obtained in the same manner as in Example 1. The resulting toner was evaluated for fixability, blocking resistance, and image stability. The results are shown in Table 2.

[0040]

[Table 1]

[0041]

[Table 2]

Comparative Examples 1 to 6 Using the raw materials having the composition shown in Table 3, antimony trioxide (work function of antimony (φ) = 4.31 eV) and dibutyl tin oxide (work function of tin ( φ) = 3.62 eV), tetratitanium oxide (titanium work function (φ) = 4.2 eV), calcium acetate monohydrate (calcium work function (φ) =
Polymerization was carried out under the same conditions as in Example 1 except that 2.82 eV) was added in the amount shown in Table 3 with respect to all the acid components, to obtain a transparent polyester resin. Table 3 shows the results of the composition analysis of the obtained resin. The glass transition temperature, the softening temperature, the acid value, the molecular weight distribution, the weight average molecular weight (Mw), and the weight average molecular weight (M
Table 4 shows the measurement results of w) / number average molecular weight (Mn). Using the obtained polyester resin, a toner was formed under the same conditions as in Example 1, and the obtained toner was evaluated for fixing property, non-offset property, blocking resistance, and image stability. The results are shown in Table 4. Was.

Comparative Examples 7 to 8 Using the raw materials having the charge compositions shown in Table 3, antimony trioxide (work function of antimony (φ) = 4.31 eV) and tetratitanium oxide (work function of titanium) were used as polymerization catalysts. Polymerization was performed under the same conditions as in Example 10 except that (φ) = 4.2 eV) was added in the amount shown in Table 3 with respect to all the acid components, to obtain a transparent polyester resin. Table 3 shows the results of the composition analysis of the obtained resin. The glass transition temperature, the softening temperature, the acid value, the molecular weight distribution, and the weight average molecular weight (M
w) and weight average molecular weight (Mw) / number average molecular weight (M
Table 4 shows the measurement results of n). Using the obtained polyester resin, a toner was formed under the same conditions as in Example 10, and the obtained toner was evaluated for fixability, blocking resistance, and image stability. The results are shown in Table 4.

[0044]

[Table 3]

[0045]

[Table 4]

The compounds used in the table represent the following: TPA: terephthalic acid TMA: trimellitic anhydride NDCA: naphthalenedicarboxylic acid EG: ethylene glycol diol A: polyoxypropylene- (2.3) -2,
2-bis (4-hydroxyphenyl) propane CHDM: cyclohexanedimethanol Sb: antimony trioxide Ti: tetratitanium ethoxide Sn: dibutyltin oxide Ca: calcium acetate monohydrate

[0047]

According to the present invention, the use of a polyester resin in which the content of a metal compound composed of a specific metal element defined by a work function (φ) is equal to or less than a specific amount as a binder resin of the toner is achieved. It is intended to provide a toner having excellent image stability without impairing the fixing property, blocking resistance and non-offset property of the toner.

Claims (3)

[Claims] An acid component comprising a dicarboxylic acid as a main component,
A diol component containing an aromatic diol and / or an aliphatic diol as a main component, and having a work function of 3.4.
A polyester resin in which the compound consisting of a metal element having eV or more is 300 ppm or less based on all acid components, having a glass transition temperature of 50 to 75 ° C and a softening temperature of 80 to
A binder resin for toner, which has an acid value of not more than 25 mgKOH / g at 170 ° C. 2. The method according to claim 1, wherein the metal element is a group IV or V of the periodic table.
2. The binder resin for toner according to claim 1, wherein the binder resin is an element having 4 or 5 periods. 3. A toner comprising a binder resin comprising the polyester resin according to claim 1 or 2 as a main component and a colorant.