JPH0354574A - Polyester resin for toner and production thereof - Google Patents

Abstract

PURPOSE:To enhance the moisture resistance, non-offsettability and blocking resistance of toner by using specific polyester for a toner used for electrostatic charge images of an electrostatic printing method, etc. CONSTITUTION:This polyester for toner consists of respectively prescribed ratios of tervalent and higher valency carboxylic acid and/or tervalent and higher valency alcohol, bivalent carboxylic acid, secondary or ternary diol and primary diol and is formed by effecting an esterification reaction or ester exchange reaction at >=240 deg.C, then condensation polymerization at <=230 deg.C. The crosslinking reaction is preferably controlled by changing the vacuum degree according to the viscosity of the polymer at the time of condensation. The resin is used by specifying the softening temp. to 100 to 170 deg.C, the glass transition temp. to 40 to 70 deg.C, the acid value to 0.5 to 30mgKOH/g and the gel fraction to 0.3 to 20%.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a low-odor Boriesdeμ resin that is ideal for toners used in electrostatic printing methods, electrophotography methods, electrostatic recording methods, etc. and its manufacturing method.

[Conventional technology and problems]

A typical imaging process for electrostatic printing, electrophotography, and electrostatic recording involves uniformly charging a photoconductive insulating layer, then exposing the layer to light, and dissipating the charge on the exposed areas. A developing process in which the electrical latent image is made visible by attaching electrically charged fine powder toner to the #@, and the resulting visible image is transferred to a transfer material such as transfer paper. It consists of a transfer step in which the image is transferred, and a fixing step in which it is permanently fixed by heat or pressure.

The performance required for toner resin that goes through the above process is as follows:
In order to impart an electric charge to the toner, it is important that the electric charge of the resin remains unchanged with respect to the operating temperature and humidity (humidity resistance). Also, in order to fix the toner on the paper during the fixing process,
The resin must have good fixing properties (fixing performance) with paper.

Furthermore, when a heat-low μ fixing method is used in a copying machine in the fixing process, it is important that the toner does not adhere to the heat roller (non-offset property).

In addition, in the fixing process, when fixing toner under high temperature conditions associated with increased copying speed, and when converting resin into toner at high temperatures, it is important that no pungent odor (odor) is generated due to the resin. .

Furthermore, when storing toner in a copy machine or printer other than the above process, toner does not block (
Blocking resistance) is required.

Conventionally, epoxy resins, styrene-acrylic resins, polyester p resins, and the like have been used as toner resins.

Among these resins, Bolieste P resin has recently attracted attention because of its good fixing performance and because it does not require or only requires a small amount of a charge control agent to control the charge.

A lot of research has been done regarding Borieste/I/resin. For example, a polyester resin has been developed in which the resin has a crosslinked structure in order to improve non-offset performance, and a polyester resin using bisphenopA-type aromatic di-fi/recipient has been developed in order to improve proton resistance. Showa 5
7-37353). The polyester resin has excellent fixing properties, anti-blocking properties, and non-offset properties, but is not good in terms of moisture resistance. Therefore, the present inventors previously developed a polyester resin with improved moisture resistance as described in Japanese Patent Application Laid-open No. S2-265227. However, recently, in order to increase the copying speed, a method of fixing at a higher temperature than before has been considered. For this reason, conventional toners have the problem of producing an irritating odor.

[Problem to be solved by the invention]

An object of the present invention is to provide a polyester/L' resin for toners that has excellent moisture resistance, non-offset properties, blocking resistance, and fixing properties and has little odor, and a method for producing the same.

[Means used to solve the problem]

The gist of the present invention is as follows: a) Trivalent or higher polyhydric carboxylic acid component of 1 to 30 μ4 based on the total carboxylic acid component and/or trivalent or higher polyhydric alcohol/I'precipitate; b) ) 70 to total carboxylic acid components
100 mo/L/4 dihydric carboxylic acid component, c) 0 to 30 mo/L'4 secondary or tertiary diol/l/part relative to the total p-boxylic acid fraction, and d) total carboxylic acid component. 7 for acid components
0 to 100 mol % of primary diol μ, and 2
After performing an esterification reaction or transesterification reaction at a reaction temperature of 40°C or higher, a condensation reaction is performed at a reaction temperature of 230°C or lower, resulting in a softening temperature of 100 to 170°C and a glass transition temperature (Tg). is 40-70℃, acid value is 0.5
The first invention is a polyester resin for toner having a polyester resin of ~30j9KOH/f and a gel μ fraction of 3 to 20'l, a) a polyvalent resin of trivalent or higher valence of 1 to 30 mol% based on the total carboxylic acid component. Carboxylic acid component and/or trivalent or higher polyvalent apco μ
b) 70 to 100 mol % divalent μ-bonic acid component based on the total carboxylic acid component, C) Secondary or tertiary or less diol of 30 moN4 or less based on the total p-bonic acid component /L' part and d) primary diol/l/part are subjected to an esterification reaction or transesterification reaction at 240°C or higher, and then 2
Maintain the reaction temperature below 30°C and 150 mHg.
Geo/I/e at the following vacuum degree. A method for producing a polyester resin for toner is provided, which comprises substantially controlling the crosslinking reaction rate by increasing the pressure of the reaction system according to the viscosity of the polymer when forming a crosslinked state while removing components. 2
invention.

Examples of the trivalent or higher polyhydric carboxylic acid component used in the present invention include 1, 2. 4-benzenetricabonic acid, 1
, 2.5-benzenetricaponic acid, 1.2.4-cyclohexanedicaponic acid, 2.5.7-naphthalenetricaponic acid, 1,2.4-naphthalenetricaponic acid,
Examples include 1,2,7.8-octanetetofukaboxylic acid and acid anhydrides thereof. Among these, particularly preferred are 1 and 2, which are easy to obtain industrially. 4-benzenetricaboxylic acid and its acid anhydride (trimellitic anhydride) are good. Examples of trivalent or higher polyvalent alcohols used in the present invention include glycerin, betaerythritol, trimethylo-propane, and nrubido-p. or,
These polyhydric carboxylic acid components and polyhydric alcohol lv may be used in combination. Further, the above trivalent or higher polyvalent μ-bonic acid component and/or trivalent or higher polyvalent ρ alcohol lv
It is preferable to use 1 to 30% of the total acid content. If it is less than 1 m/l/1, it will be difficult to obtain non-offset properties that will deteriorate the physical properties of the toner, and if it exceeds 30 m/l, the Tg of the resin will be low, blocking resistance will be poor, and crosslinking reaction will occur during manufacturing. This is not desirable because it becomes difficult to control.

Examples of the dicarboxylic acid component used in the present invention include Eha 1.
．． 2-propanedicabonic acid, 1,3-butanedicabonic acid, 2.3-butanedicabonic acid, 3-methymu-glutaric acid, 2.2-dimethy/'l'-1.3-propanedicabonic acid Acid, 1-2-1,000 μ-1.5-propanedicabonic acid, isophthalic acid, dimethic isophthalic acid, terephthalic acid, dimethic terephthalic acid, maleic acid, cyclohexane dicaponic acid, adivic acid, Examples include sepacic acid, naphthalene dicarboxylic acid, and/or acid anhydrides thereof. Among these, particularly preferred are isophthalic acid, dimethic isophthalic acid, dimethic isophthalic acid, dimethic isophthalic acid,
It is preferable to use one or more types of cyclohexane dicarboxylic acid. Resin using terephthalic acid component has high Tg,
The blocking resistance of the toner is improved. Further, the resin using a certain amount of isophthalic acid has a low softening temperature, and the low-temperature fixability of the toner is improved. Furthermore, a resin using cyclohexanedicapboxylic acid is good because it has a high Tg and a low softening temperature. For example, when terephthalic acid and isophthalic acid are used in combination, the mixing ratio is ao ~ 100 μm of terephthalic acid, 0 to 100 μm of terephthalic acid, and
Preferably, the isophtha/I' acid component is 60 moA/4. When terephthalic acid component and cyclohexanedicarboxylic acid component are used together, the mixing ratio is 40 to 100 motv4 to terephthalic acid component,
Preferably, the amount of cyclohexane dicarboxylic acid is 0 to 40 mol %.

Next, examples of the secondary or tertiary diol μ according to the present invention include hydrogenated bisphenol μA, polyoxypropylene bis(4'-hydroxyphenylene 71%/) globan, 1,4-benzenedio μ, Bisphenol/L'
A, bisphenol/l'AIF, bisphenol/I/S
etc. Among them, hydrogenated bisphenol/l/A, polyoxypropylene-bis(4'-hydroxyphenylene A/)propane, and the like are preferred from the viewpoint of reactivity. The above georho
In some cases, 0 to 50 mo/I/% based on the total carboxylic acid component
Good to use. The above geo/%/e. minute to 30 μ
If an amount exceeding 100% is used, an irritating odor will be generated after the toner is formed, which is not desirable.

Examples of the first-class geo/l' classification according to the present invention include:
t ethylene glycol μ, diethylene glyco/L'1
}! J ethylene glycol/L', 1,2-brobylene glycol ~, 1,3-probi V glycol p11.6-
Hexanediol ρ, 2.5-hexanediol, Neobenchμ Crico μ, Cyclohexane dimethanol μ, 1.
2-butanedioh μ, 1,3-butanedioh μ, 1,4
-Ptanedioμ, boroxyethylene-vinu(4'-
Examples include hydroxyphenylene/V) propane, ethyl p-propylene glycol μ, buty-μ ethyl propylene glycol. Among them, polyoxyethylene-bis(at-hydroxyphenylene/%/)propane and ethylene crico μ are used to improve reactivity and increase the Tg of the resin.
It is preferable to use one or more of , neobenchi p-glycol, cyclohexanedimethanol μ, and the like.

The softening temperature of the resin used in the present invention is 100 to 170°C, preferably 120 to 150°C. Softening temperature is 1
In the region below 00℃, the 'rg of the resin is low.
This is not preferred because the blocking resistance becomes poor. On the other hand, if the softening temperature exceeds 170° C., the low-temperature fixability of the toner will be poor, which is undesirable.

The Tg of the resin according to the present invention is 40°C to 70°C. If the rg of the resin is less than 40°C, it is not preferred because it is easily affected by room temperature and the blocking resistance is poor. vice versa,
If Tg exceeds 70°C, the crushability of the resin becomes poor, which is not preferable.

Acid value of resin used in the present invention CL 5 xg xoH/
y~s O*KoIII/t. Preferably it is 5 to 2519 KOH/f. A resin having an acid value outside this range is not preferred because it is difficult to maintain the most suitable charge amount as a toner.

The resin used in the present invention has a Ge fraction of 0.31 to 20. If the gel μ fraction is less than cL5'6, the offset resistance will be poor, and if it exceeds 20%, the low temperature fixing property will be poor.

The method for producing the polyester/L' resin for toner according to the present invention includes the above-mentioned trivalent or higher polyvalent carboxylic acid component and/or trivalent or higher polyvalent acid component Iv, divalent strength μ
Preference is given to using dioxylic acid, secondary or tertiary diol/L/diamine, primary diio/L/diamine. The ratio of these total carboxylic acid components to the total diol μ precipitate can be set in the same way as in the case of the usual polyester production method, but in terms of reactivity (the mo μ number of the total diol μ precipitate) /(total carboxylic acid fraction/%/number): (19 to 2.5 is preferred.

The most important thing in this production method is the reaction temperature conditions during the esterification reaction, transesterification reaction, and condensation reaction. Concerning the reaction temperature conditions for the usual polyester production method, the condensation reaction is carried out at a reaction temperature that is about 20°C higher than the reaction temperature during the esterification reaction and the transesterification reaction. The temperature conditions related to this manufacturing method are
2 in terms of reactivity in chemical reaction and transesterification reaction.
The temperature is preferably 40 to 270°C, and the condensation reaction is preferably carried out at 160 to 230°C from the viewpoint of reactivity. If the esterification reaction temperature is below 240° C., the reaction rate will not increase, the esterification reaction will proceed during the condensation reaction and even after the reaction is stopped (removal of the reduced pressure), and the gep-formation reaction will not be stopped, which is not preferable. On the other hand, when the condensation reaction temperature is as high as 230°C, secondary or tertiary diol IvIli! ! This is undesirable because the components decompose and the resulting resin produces a pungent odor, and the crosslinking reaction speed is slow, making it difficult to control the crosslinking reaction.

What is important in this production method is to maintain the above condensation reaction temperature and conduct the diode/
When forming a crosslinked state while gradually removing the L' component, the pressure of the reaction system is increased depending on the viscosity of the polymer to substantially control the crosslinking reaction rate. Vacuum degree is 150mm
If the amount exceeds Hg, the amount of distillation of the 1 μm fraction of dioxic acid will be small and the crosslinking reaction will be difficult to occur, which is not preferable. If the pressure in the reaction system is not increased according to the viscosity of the polymer, the crosslinking reaction of the polymer will proceed rapidly, making it impossible to control the crosslinking reaction rate, and the resin will eventually become rubbery in the reaction vessel. To take it out
<It is not good for industry because it meets the other people.

As the polymerization catalyst in the wood production method, a polymerization catalyst normally used in the polyester production method can be used. For example, antimony dioxide, tetrafluorocarbonate, zinc acetate, germanium dioxide, magnesium dioxide, manganese dioxide, etc. can be mentioned.

The acid value of the resin used in the present invention is determined by the titration method using KOIII, and the acid value is D and Tg is DE.
The softening temperature was determined by the IO method (heating rate 5/min) using a flow tester with a nozzle μ of 1.0 φ x 10 μ.
OIFT-500, manufactured by Shimadzu Corporation), a load of 30
The temperature is determined by measuring the temperature when κ flows out of a 1F sande using a method of measurement under constant temperature increase at a temperature increase rate of 3° C./min. Furthermore, the gel fraction is calculated by putting sump/L'l5F into Tetowohydrofufun50+d,
The value is the weight obtained by heating and dissolving at 70°C for 3 hours, filtering through a gaff filter lined with Celite ◆545, and thoroughly drying at 80°C in a vacuum dryer, dividing the weight by the initial weight.

The present invention will be explained below using examples. The present invention is not limited to the embodiments described below.

[Example 1] Terephtha-μ acid, inphtha-μ acid, V-chlorohexane dicarboxylic acid, hydrogenated bisphenol 4-Hydroxypheny A/) globan, ethylene glycol μ, neobentyl glycol μ
, chlorohexanedimethanol, and trimellitic anhydride were charged into a reaction vessel according to the set shown in Table 1-1. Next, antimony dioxide, which is a polymerization catalyst, was added at 500 ppm based on the total amount of acid, and the internal temperature was 260°C and the stirring rotation speed was 200 r, p, m. The ester p-formation reaction was carried out while maintaining the temperature. The esterification reaction was carried out for about 4 hours in the casing where the esterification reaction started, the distillation of water from the reaction system began, and the distillation of water was completed. At that point, no Gep conversion reaction occurs,
The stirring torque meter is OK! - cm was shown.

Next, the internal temperature of the reactor was lowered to 200° C. by air cooling, and the condensation reaction was carried out under this temperature while maintaining the stirring rotation speed at 20 Or, p, m. Reduce the pressure of the reaction system to about 150 mmH.
Distillation of the Geo-μ component started at about 100 g. Then, about 40 minutes after the start of pressure reduction, the pressure of the reaction system decreased to about 11 Hg.
It became. The stirring torque meter at this point was 0-1. Furthermore, after approximately 4 hours had passed since the start of decompression,
The melt viscosity of the reaction system increased gradually. Sweeping torque is approximately 3
kl? Since the viscosity began to rise rapidly at the point of collapse, the pressure of the reaction system was increased to about 251 kg. For a while, the stirring torque showed 5-1°. Approximately 10 minutes after changing the pressure, the viscosity of the reaction system began to increase, and when the stirring torque reached approximately 4.5 m, the viscosity of the reaction system began to increase rapidly. pressure of 50mmH
It was set as g. After the pressure of the reaction system was set to 50 wIg, the stirring torque was set to about 4.5 mm for about 10 minutes. 5 k9-e
xa, but after that the viscosity of the reaction system started to increase gradually. Approximately 5 hours after the pressure in the reaction system started to be reduced, the viscosity of the reaction system increased and the desired stirring torque was reached.
The reaction system was returned to normal pressure.

Thereafter, the stirring rotation speed was increased to 20 O r, p. m. As a result of observing the stirring torque for about 1 hour, the stirring torque was about &Ok9-country and was constant. The relationship between the reduction time required for the above manufacturing process, the pressure of the reaction system, and the stirring torque is shown below.

Resin A-L was obtained by the above production method. These specifications and physical property values are shown in Table 1-2. Next, each of the resins ▲ to L was kneaded using a twin-screw extruder at a mixing ratio of 95 parts by weight of the resin and 5 parts by weight of the car pump hook. After that, it is finely pulverized with a jet mill, the particle size is adjusted with a classifier, and the toner A-L
I got it.

Next, using a thermal heatloaf one-type fusing tester that can freely change the temperature, roller speed, and roller pressure, the roller pressure was adjusted to a nip width of 5, and the roller speed was adjusted to 2.
A fixing test was carried out for toners ▲ to L under the condition of 00 cm/sec. The fixing temperature range is shown by the roller temperature when the fixing rate of paper and toner exceeds 90, and the low-fu temperature when hot offset occurs. The fixing rate was measured using a Macbeth reflection densitometer, and the ratio of the density of the toner fixed on the paper to the density after peeling off with a tape was taken as the fixing rate. The results obtained are shown in Table 1-3. As is clear from Tables 1-3, toner A-T. + means fixability;
It had excellent offset properties.

Next, put 1F each of toner A-L into the sump μ bottle, and
It was placed in a hot air dryer kept at ℃ and left for 50 hours to evaluate blocking resistance.

The results are shown in Table 1-3. As is clear from Table 1-3, Toner A-L had good blocking resistance.

Next, toners A to L are finely pulverized to a particle size of 5 to 20 μm.
1. I put Of into a sample bottle and checked the odor. The results are shown in Table 1-3. All of the toners had almost no odor, and no odor was generated even when a fixing test was conducted at 200°C.

Table 1 3 *1 Blocking resistance evaluation criteria ▲: Toner disperses just by turning the Sande μ bottle upside down.

B: Tap once at l to disperse the toner.

0: # Tap 2 to 4 times to get D
: # 5-6 times Mail abuse:
l It does not disperse even if you tap it several dozen times.

Usable level/v C or higher. *2 Inauthenticity evaluation criteria ▲: 1 out of 10 people answered that the smell was bad.

B: Up to 3 out of 10 people answered that it smells bad.

C: 5 out of 10 people answered that it smells bad.

D: Up to 7 out of 10 people answered that they could smell it.

m: 8 or more people out of 1o answered that they could smell it. Usable rep/%/ O or more.

[Example 2] Dimethylene terephthalate, dimethylene inphthalate, polyoxypropylene bis(4-hydroxypropylene/L/)
Globan, Horioki V ethylene-bis(4-hydroxyphenyμ)propane, ethylene glycol μ, and trimellitic anhydride were charged into a reaction vessel according to the set in Table 2-1. Next, as a polymerization catalyst, 500 ppm of tetofuptititanate based on the total carboxylic acid components was added.

The relationship between transesterification, condensation thread pressure, and stirring torque is shown under the same conditions as in Example 1.

Next, each resin was converted into toner under the same conditions as in Example 1.
Toner M-0 was obtained. Next, the fixing properties, blocking resistance, and odor properties were evaluated. The results are shown in Table 2-3. From Table 2-3, toner M-0 was excellent in fixing properties, anti-blocking properties, and odorless properties.

Table 2-1 Monomer symbol (Table 2-1, Table 2-2) DMT: Dimethylphate terephthalic acid p DMI: Dimethyphic acid μ ? M▲Trimellitic dianhydride BP: rtt lyoxypropylene bis(4-hydroxyphene A/) broban BIli: pholyoxyethylene bis(4-hydroxy V
Phenyl lv) Propane angle G: Ethylene glycol ρ Table 2-3 [Comparative example 1] Terephtha μ acid, isophtha μ acid, polyoxyethylene-bis(4-hydroxypheny/I/) 7” loban, trimellitic anhydride, Ethylene glycol was charged into the reaction vessel according to Table 3-10. Next, antimony trioxide, which is a polymerization catalyst, was added at a rate of 500 to 500% of the total carboxylic acid.
ppm was added, and the esterification reaction and condensation reaction were carried out under the same conditions as in Example 1. As a result, resins P and Q were obtained in which both the condensation reaction and the crosslinking reaction rate were controllable. The physical properties of resin P%q are shown in Table 3-2.

Next, resins P and ctt were pressed under the same conditions as in Example 1 to obtain toners N and O, and the fixing test, anti-blocking properties, and odorless properties were evaluated. The results are shown in Table 3-5.

Toner P had good blocking resistance and fixing properties, but in the odor test it produced a pungent odor that stung the nose.

Furthermore, since the toner Qp/Tg was low, the blocking resistance was poor.

Table 3-1 Table 3-3 [Comparative Example 2] Table 3-1 Table 3-3 [Comparative Example 2] Te V7 taic acid, iso7 taic acid, polyoxyderopi V-bis(4-hydroxyphenylene/I/)propane, ethylene glycol μ, trimellitic anhydride. According to the set of 4-1, antimony trioxide 400p which is a polymerization catalyst
pm was charged into the reaction vessel. The internal temperature was 260°C, and the stirring rotation speed was 20 Or, p. The SDE μ-ization reaction was carried out while maintaining the temperature at m.

About 4 hours after the start of water distillation, water distillation stopped and the esterification reaction was completed. Next, the internal temperature was set to 285°C, and the stirring rotation speed was set to 200 r, p. The condensation reaction was carried out while maintaining the temperature at m.

Approximately 2 hours after the start of depressurization of the reaction system, the viscosity of the reaction system rapidly increased, and the stirring torque meter changed from 8kg-α to 4kg-α in just a few seconds. At this time, the pressure in the reaction system was increased to 100 mmHg, but the crosslinking reaction rate did not slow down, and the stirring torque was 6.5 mm per second. 0 kg-e
It rose to M1.

At this point, the reaction system was returned to normal pressure, but the agitation valve still turned up and reached the unmeasurable region.

Then, I stopped stirring and tried to take out the resin, but the resin was in the shape of rubber and was removed from the reaction vessel. Polyoxy V propylene bis (4-hydroxyphene A/) 7' loban, ethylene glycol, cyclohexanedimethanol, pentaerythritol μ, trimethylo μ propane, glycerin,
Sopbido μ was charged into a reaction vessel according to Tables 5-10, and then antimony trioxide and zinc acetate, which were polymerization catalysts, were each added at 500 ppm based on the total acid content. Set the internal temperature to 265℃ and the stirring rotation speed to 20Or, p.
, m, and the esterification reaction was carried out.

Approximately 5 hours after the reaction system water was distilled off, no more water was distilled out, and the esterification reaction was completed. At this point, stir
The meter showed Ok9-51. Then, the temperature of the reaction system was lowered to 200°C by air cooling, and when the internal temperature was maintained at 200°C, the stirring rotation speed was increased to 20°C.
, p, m. and started depressurization. Approximately 4 hours after the start of pressure reduction, the viscosity of the polymer in the reaction system began to increase, and the stirring torque began to increase. At this point, the pressure in the reaction system was changed to control the crosslinking reaction rate under the same conditions as in Example 1. As a result, resin 8-Y was obtained.

The physical properties of Resins 8 to Y are shown in Table 5-2.

Next, under the same conditions as in Example 1, toner El was mixed with resin S-Y.
-Y was obtained. Further, toner sy was evaluated under the same conditions as in Example 1 for blocking resistance, fixing properties, and odorlessness. The results are shown in Table 5-3. As is clear from Table 5-3, Toners 8 to Y were excellent in fixing properties, non-offset properties, blocking resistance, and odorlessness.

Table 5-1 *Monomer symbols in Tables 5-1 and 5-2 TPA: Terephthalic acid iPA: Isophthalic acid BP: Voriquine propylene bis(al-hydroxyphenylene/%/)Derovan OHDM: Cyclohexane di Methanol μPI! ! N
: Bentaerythritol μ TMP : } Rimethylo μ Propane GR : Glycerin 8B : Sorbitol Table 5-3 [Comparative Example 5] Derephtha μ acid, isophtha p acid, borioquine derovyrene bis(4'-hydroxy Vpheni/I) /) 7' Loban, Ethyl V glycol μ, trimellitic anhydride, and pentaerythritol were charged into a reaction vessel according to Tables 6-10. Next, after adding a polymerization catalyst according to Examples 1 and 5, the internal temperature of the reaction system was set to 255°C, and the stirring rotation speed was set to 200 r.
, p, m. The SDP conversion reaction was carried out by maintaining the temperature at Approximately 4 hours after the start of distillation of water from the reaction system, no more water was distilled out, and the Siemete p-formation reaction was completed. Next, increase the stirring speed to 2.
0 o r. p. m. The reaction temperature was set according to Table 6-1, and pressure reduction was started. Approximately 4 minutes after starting decompression
After some time, the viscosity of the polymer in the reaction system began to increase, and the stirring torque began to increase. At this point, as in Example 1, the pressure in the reaction system was changed to control the crosslinking reaction rate. As a result, in all cases, the viscosity of the resin increased during removal, and removal could not be completed.

Table 6-1 *Symbols of monomers in Table 6-1 TPA: TeV phthalic acid iPA: Isophthalic acid BP: Borioxypropylene-bi x (a'-hydroxypheni/I/)propane EG: Ethyl V glycol p PEN: Pentaerythritol [Effects of the Invention] As detailed above, the production method of the present invention makes it possible to stably obtain a polyester resin with a desired degree of crosslinking, and also makes it possible to stably obtain a polyester resin with a desired degree of crosslinking. By using the resin as a toner binder, it is possible to obtain a toner that is excellent in blocking resistance, non-offset property, low-temperature fixing property, and odorless, and its effects are extremely large.

The condensation times used during the actual condensation reaction and those of 2 in the reaction system are shown respectively.

In the figure, the horizontal axis is the condensation reaction time (hr), the right vertical axis is the degree of vacuum (mmHg), and the left vertical axis is the stirring torque (μ・5m).
), the solid line in the figure represents the stirring torque curve, and the broken line represents the degree of vacuum.

Claims (1)

[Claims] 1. a) 1 to 30 mol% of 3 based on the total carboxylic acid component
a polyhydric carboxylic acid component having a valence of 70 to 100 mol% based on the total carboxylic acid component;
c) a secondary or tertiary diol component of 0 to 30 mol% based on the total carboxylic acid component, and d) a primary diol component of 70 to 100 mol% based on the total carboxylic acid component. After carrying out the esterification reaction or transesterification reaction at a reaction temperature of 240°C or higher,
The softening temperature obtained by performing the condensation reaction at a reaction temperature of 230°C or lower is 100 to 170°C, and the glass transition temperature is 40 to 40°C.
A polyester resin for toner having an acid value of 0.5 to 30 mgKOH/g and a gel fraction of 0.3 to 20% at 70°C. 2, a) 1 to 30 mol% of 3 based on the total carboxylic acid component
a polyhydric carboxylic acid component having a valence of 70 to 100 mol% based on the total carboxylic acid component;
Carboxylic acid component, c) 0 to 30 mol% of secondary or tertiary diol component based on the total carboxylic acid component, and d) primary diol component are subjected to an esterification reaction or transesterification reaction at 240°C or higher. Then, when forming a crosslinked state while maintaining the reaction temperature at 230°C or lower and removing the diol component under a vacuum level of 150mmHg or lower, the pressure of the reaction system is increased depending on the viscosity of the polymer to substantially crosslink. A method for producing a polyester resin for toner, characterized by controlling the reaction rate.