JP3464695B2 - Polyester resin for toner and method for producing the same - Google Patents

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 dry toner used for developing an electrostatic image or a magnetic latent image in an electrophotographic method, an electrostatic recording method, an electrostatic printing method and the like, and a method for producing the same. More specifically, regarding the polyester resin for a toner having a relatively high glass transition point, a high toughness, excellent printing durability and fixing property as a toner, and particularly effective for a non-magnetic-component type developing system, and the production thereof. Regarding the method.

[0002]

2. Description of the Related Art In a method of obtaining a permanent visible image from an antistatic image, an electrostatic image formed on a photoconductive photosensitive member or an electrostatic recording material is developed with a toner charged in advance by friction. Is fixed. In the case of a magnetic latent image,
The latent image on the magnetic drum is developed with toner containing a magnetic material and then fixed. For fixing, the toner image obtained by development is directly fused on the photoconductive photoreceptor or the electrostatic recording body, or the toner image is transferred onto paper or film and then fused onto the transfer sheet. Done by.
Toner image fusion is performed by contact with solvent vapor, pressurization and heating, and 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.

Toner used in the dry developing system is 1
There are two-component toners and two-component toners. The two-component toner is prepared by first melt-kneading a resin, a colorant, a charge control agent and other necessary additives to sufficiently disperse them, then coarsely pulverizing them and then finely pulverizing them to classify them into a predetermined particle size range. Manufactured. The one-component toner is manufactured in the same manner by adding magnetic iron powder in addition to the respective components of the above two-component toner.

Since the resin is the main component in the toner formulation, it controls most of the performance required for the toner. For this reason, the toner resin is required to have good dispersibility of the colorant in the melt-kneading step and good pulverizability in the pulverizing step in the toner production.
Various performances such as good offset property, blocking property, and good electrical property are required. Resins used in the production of toner include epoxy resins, polyester resins,
Polystyrene resins, methacrylic resins and the like are known, but copolymers of styrene and (meth) acrylic acid ester have been mainly used for the pressure-bonding heat fixing system. But,
Polyester resins have been attracting attention because they can be fixed at lower temperatures and the toner images on which they are fixed have excellent PVC plasticizer resistance.

However, as the performance of copying machines has increased, the points of performance required for the resin for toner have also changed depending on the type of copying machine. Among them, the small-sized copiers (portable type), which have recently become extremely popular, are often used for home use, etc., so the printing rate is relatively low and the toner is used in the developing process inside the copier. Mixing takes a long time due to charging. During that time, the toner is crushed, the particle size becomes smaller, and the charge amount changes. Therefore, the density of the copy machine changes.
Further, in such household copying machines and plain paper facsimiles, a non-magnetic-component type developing system has been used for the purpose of machine downsizing and maintenance-free, and the toner is strongly pressed against the developing roll. The method of charging is adopted. In such a development system,
Since the toner is easily pulverized by rubbing the toner on the developing roll in the charging step, the charge amount of the toner is likely to change, and the frictional heat generated during rubbing causes the toner to be fused or the toner to the roll. It has problems such as adhesion.

When a styrene resin is used as the toner resin in the developing system as described above, the toner is easily crushed due to insufficient strength of the resin, causing fog on the subject or lowering the density. There is a problem. In order to improve it, a method of making it ultra-high polymer or raising the glass transition point Tg is adopted, but the viscosity increases sharply and the fixability decreases.

Polyester resins, which are said to be stronger than styrene resins, are also used for toners, but because of the importance of fixability, many of them have a high crosslinking agent concentration and a number average molecular weight Mn. However, the developing system as described above does not have sufficient strength.

In order to satisfy both fixability and non-offset property at the same time, it has been proposed to use a polyfunctional monomer at a high concentration to extend the molecular weight distribution, but the number average molecular weight Mn is lowered and the toughness is lowered. Is a problem.
It has also been proposed to use a propylene oxide adduct of bisphenol A to improve this brittleness. However, this monomer has very poor reactivity, and when a large amount of this monomer is used, the reaction does not proceed to a predetermined degree of polymerization.

In order to solve these problems, it has been proposed to use an ethylene oxide adduct having relatively high reactivity even in a bisphenol A derivative, but the ethylene oxide adduct of bisphenol A has a glass transition point Tg. It is not possible to use much because it causes a decrease in In addition, since the ethylene oxide adduct of bisphenol A is a solid, it is necessary to pulverize it when it is used as a monomer, so that the cost is high, and the resin using the resin is widely used in copying machines. Not suitable for use in printers. Further, when polymerizing a polymer, there is a problem that the ethylene oxide adduct of bisphenol A, which is a block, is difficult to make into a slurry and the amount used is limited.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above drawbacks, and its object is to have a relatively high glass transition point and a high toughness. It is an object of the present invention to provide a polyester resin suitable as a non-magnetic component toner having excellent fixability and printing durability as a toner, and a method for producing the same.

[0011]

Means for Solving the Problems As a result of intensive investigations aimed at achieving the above object, the present inventors have used a specific amount of a specific component as an acid component and a diol component and have a polyhydric alcohol having a valence of 3 or more. The present invention has been completed by finding that a polyester resin containing a polymer as a polymer component and having specific physical properties can achieve the object. That is, the present invention is
(A) 60 based on terephthalic acid as a main component based on all acid components
An acid component containing at least mol% of an aromatic dicarboxylic acid,
(B) A diol component containing 10 to 60 mol% of an aromatic diol represented by the following formula (I) based on the aliphatic diol and the total acid component, and (c) 1 to 13 mol% based on the total acid component.
And a glass transition point Tg of 60 to 85 ° C. and a toughness index of 350 to 600 μm.

[Chemical 3]

The present invention further comprises an acid component containing terephthalic acid as a main component and 60 mol% or more of an aromatic dicarboxylic acid with respect to the total acid component, and 10 to 60 mol with respect to the aliphatic diol and the total acid component. % Of the diol component containing 100% of the aromatic diol represented by the following formula (I) and 1 to 1 with respect to the total acid component.
3 mol% of a trifunctional or higher polyhydric alcohol was mixed so that the molar ratio of the alcohol component to the acid component was 1.3 or less, and the esterification reaction or transesterification reaction was performed at a temperature of 250 ° C. or higher. After that, a polymerization reaction is performed, and a toughness index is 350 to 600 μm and a glass transition point Tg is 6
A method for producing a polyester resin for toner, which comprises producing a polyester resin having a temperature of 0 to 85 ° C.

[Chemical 4]

The present invention will be described in detail below. The acid component (a) used in the present invention contains terephthalic acid as a main component, and contains 60 mol% or more of an aromatic dicarboxylic acid composed of an aromatic dicarboxylic acid or a lower alkyl ester thereof, with respect to the total acid component. Consists of including. The aromatic dicarboxylic acid used as the acid component (a) is useful for increasing the moisture resistance of the toner because it has a highly hydrophobic benzene ring.

Examples of lower alkyl esters such as terephthalic acid and isophthalic acid used as the acid component (a) include, for example, dimethyl terephthalic acid, dimethyl isophthalic acid, diethyl terephthalic acid, diethyl isophthalic acid,
Examples thereof include dibutyl terephthalic acid and dibutyl isophthalic acid, and dimethyl terephthalic acid and dimethyl isophthalic acid are preferable in terms of cost and handling. The above aromatic dicarboxylic acid or lower alkyl ester thereof,
They may be used alone or in combination of two or more.

The aromatic dicarboxylic acid has an effect of increasing the glass transition point Tg (hereinafter simply referred to as Tg) of the obtained resin and contributing to the improvement of blocking resistance. Therefore,
The aromatic dicarboxylic acid must be contained in an amount of 60 mol% or more, preferably 70 mol% or more, based on all acid components.
Among them, the terephthalic acid type is effective in increasing the toughness and Tg of the resin, and is contained in an amount of 50 mol% or more, preferably 60 mol% or more based on the total acid components. Further, since the isophthalic acid type has the effect of increasing the reactivity, it is necessary to change the use balance depending on the purpose.

In the present invention, examples of other dicarboxylic acids which can be optionally used as the acid component (a) include phthalic acid, sebacic acid, isodecyl succinic acid,
Maleic acid, fumaric acid, adipic acid, and their monomethyl, monoethyl, dimethyl, diethyl ester, etc.,
And these acid anhydrides. These divalent carboxylic acid components have a great influence on the fixing property and blocking resistance of the toner. Therefore, depending on the required performance of the resin, the range of not impairing the object of the present invention, 30 mol% or less based on the total acid components. It can be contained in a certain degree.

The diol component (b) used in the present invention comprises an aromatic diol and an aliphatic diol. In the present invention, a specific amount of the aromatic diol represented by the above formula (I) is used as an essential component as the diol component (b). Use of the aromatic diol represented by the above formula (I) is effective for imparting toughness to the polyester resin and controlling the crosslinking reaction which proceeds rapidly in the polyester due to its low reactivity. Therefore, the content of the aromatic diol of the formula (I) in the diol component (b) is in the range of 10 to 60 mol% with respect to the fatty acid diol and the total acid component, preferably 20.
Is about 60 mol%. When the amount of the aromatic diol of the formula (I) used is less than 10 mol% with respect to the aliphatic diol and the total acid components, there is no effect of improving the toughness and it is difficult to control the crosslinking reaction. On the other hand, when the amount of the aromatic diol of the formula (I) used exceeds 60 mol%, the reactivity of the entire system decreases, and the reaction may not reach the gel point within the above composition range. Further, since the aromatic diol has an effect of increasing the Tg of the resin, the blocking resistance becomes good.

As an example of the aromatic diol represented by the formula (I) used in the present invention, polyoxyethylene-
(2.0) -2,2-bis (4-hydroxyphenyl)
Propane, polyoxypropylene- (2.0) -2,2
-Bis (4-hydroxyphenyl) propane, polyoxypropylene (2.2) -polyoxyethylene- (2.
0) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (2.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (6) -2,2 -Bis (4-hydroxyphenyl) propane, polyoxypropylene (2.3) -2,
2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.4) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4 -Hydroxyphenyl)
Propane and the like can be mentioned, and these can be used alone or in admixture of two or more.

Further, examples of the aliphatic diol used as the diol component (b) include ethylene glycol and
Commonly known monomers such as neopentyl glycol and 1.4-butanediol are included. The aliphatic diol not only enhances the reactivity, but also imparts flexibility to the resin and contributes to the fixing property of the toner, but on the other hand, if a large amount is contained, Tg is increased.
To lower the blocking resistance. Therefore, it is possible to obtain a desired toner resin by changing the content of the aliphatic diol according to the purpose, but in order to improve the toughness, the reactivity is increased to obtain a high molecular weight polyester resin. The amount of the aliphatic diol is preferably 20 to 80 mol%, more preferably 40 to 80 mol%, based on the total acid components for the purpose of maintaining the fixability of the toner. .

The trihydric or higher polyhydric alcohol component (c) used in the present invention is a component that crosslinks the polyester to impart toughness. Examples of the trihydric or higher polyhydric alcohol component (c) used include sorbitol,
1,2,3,6-hexanetetralol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentatriol, glycerol , 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like, which may be used alone or in combination. . Since such a polyfunctional monomer has the effect of increasing the toughness and Tg of the resin, and the effect of imparting cohesiveness to the resin and increasing the offset resistance, the content thereof is the fixing temperature of the copying machine used and the copying temperature. It may be freely set according to the speed, but from the viewpoint of toughness, it is 1 to 13 mol%, preferably 1 to 10 mol%.

This is because if the polyhydric alcohol having a valence of 3 or more is less than 1 mol%, a sufficient crosslinked structure cannot be imparted to the polyester resin. On the other hand, when the content exceeds 13 mol%, the reaction of the three-dimensional structure portion becomes preferential and it becomes difficult to impart sufficient strength to the polymer. Specifically, while the main chain of the polymer does not grow sufficiently, it reaches the gel point and begins to form a network structure,
The melt viscosity of the polymer itself increases, but the toughness of the resin decreases.

When the trifunctional polycarboxylic acid is used, the content of the trifunctional or higher polycarboxylic acid is preferably 5 to 13 mol%, more preferably 5% by mole based on the total acid components. It is in the range of 10 to 10 mol%, and when a polyfunctional carboxylic acid having a functionality of 4 or more is used,
10 mol% is preferable, and 1 to 7 mol% is more preferable.
Is the range.

Further, in the present invention, by using a polyhydric alcohol as the polyfunctional monomer, the reactivity is improved and the productivity is excellent and the polyhydric carboxylic acid is comparatively used as compared with the case where the polycarboxylic acid is used. Even when the Tg is low, a polyester resin having high toughness can be obtained, and when used as a toner, the fixing property can be improved while maintaining good printing durability.

It is important that the polyester resin for toner of the present invention having the above constitution has a Tg of 60 to 85 ° C. and a toughness index of 350 to 600 μm.

This is because if the Tg is less than 60 ° C., the toner is fused and the image is deteriorated in the charging step, or the toner adheres to the developing roll to contaminate the roll.
This is because if the temperature exceeds 5 ° C., the fixability will decrease. The Tg is preferably in the range of 65 to 80 ° C.

The toughness index in the present invention is obtained by the resin toughness evaluation method described below.

Resin toughness evaluation method: pulverized polyester resin is sieved to obtain a particle size of 1400 to 1400.
Prepare 50 g of a 2000 μm sample. 30g of the classified sample of blender TR made by Trio Science
-Pulverize with BL. (Scale 10:30 seconds) A sieve whose mass was weighed had a mesh size of 100 μm, 1
50 μm, 250 μm, 500 μm, 710 μm and 1
Assemble from below in the order of 000 μm. 20 g of the finely pulverized product obtained by the above operation is weighed. The finely pulverized product is put on the uppermost part of the sieve assembled with, and vibrated for 30 minutes with a micro electromagnetic vibrating sieve M-2 type manufactured by Tsutsui Rikiki.
(Scale 10) Weigh the resin on each sieve.
The resin weight on each sieve is plotted on a semi-logarithmic graph (cumulative weight of each mesh pass), and the particle size at which 50% by weight of the whole passes is read from the graph.

In the present invention, the particle size is 3 according to the above evaluation method.
When a toner using a resin of less than 50 μm is used, the toughness of the toner is weak, the toner is crushed during development in the copying machine, the charge amount of the toner is changed, and the image density is affected. In addition, according to the above evaluation method, the particle size is 600
When a toner containing a resin of more than μm is used, the toughness of the resin is good, and it is possible to suppress crushing in the copying machine and generation of spent toner, but the strength of the toner is high, so fixing is an important factor as a toner. Reduce sex. Therefore, in the above evaluation method, the pulverized particle size is 350 to
It needs to be 600 μm, preferably 400 to 550 μm.

Further, the toughness and T of the polyester resin are
In order to increase g, it is preferable that the charged molar ratio of the alcohol component to the acid component is 1.3 or less, more preferably 1.2 or less when the monomer is charged into the reaction kettle. Furthermore, if the charged molar ratio of the alcohol component is reduced, the reactivity of the polyester is lowered. Therefore, the esterification reaction or transesterification reaction should be performed at a high temperature of 250 ° C. or higher and under a high pressure of about ^{2 to 4} kg / cm ² G. Is preferred, and more preferably 260
Is in the range of to 275 ° C.

The polyester resin of the present invention preferably has a softening temperature of 80 to 180 ° C, more preferably 95 to 170 ° C. It has a softening temperature of 9
When the temperature is lower than 0 ° C, the fixability is improved, but the cohesive force of the resin is extremely reduced, and sufficient anti-offset property tends not to be obtained. Conversely, when the softening temperature is higher than 180 ° C. This is because the non-offset property is improved, but the fixability tends to be extremely lowered.

In the production of the polyester resin for toner of the present invention, the above-mentioned polymerization components (a) to (c) are charged into a reaction kettle and heated to heat to carry out an esterification reaction or a transesterification reaction. At this time, if necessary, an esterification catalyst or a transesterification catalyst used in a usual esterification reaction or transesterification reaction such as sulfuric acid, titanium butoxide, dibutyltin oxide, magnesium acetate, manganese acetate can be used. . Then, water or alcohol generated in the reaction is removed according to a conventional method. After that, the polymerization reaction is continued, but at this time, 150 m
Polymerization is performed while distilling off the diol component under a vacuum of mHg or less.

In the polymerization, generally known polymerization catalysts such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide and germanium dioxide can be used. Further, the polymerization temperature and the catalyst amount are not particularly limited, and may be arbitrarily set as needed.

In the polyester resin for toner of the present invention, if necessary, an inorganic powder such as silica may be added to improve the blocking resistance. The effect of adding the silica powder is particularly remarkable when the Tg of the binder resin is low.

[0034]

EXAMPLES The present invention will be specifically described below with reference to examples. The performance evaluation in Examples and Comparative Examples was performed using the following methods.

(1) Softening temperature (° C.) Flow tester (CFT-50, manufactured by Shimadzu Corporation)
No. 0), the softening temperature (° C.) was the temperature at which half the sample flowed out under the conditions of a nozzle of 1.0 mmφ × 10 mmL, a load of 30 kg, a temperature increase of 3 ° C./min, and a sample amount of 1.0 g.

(2) Tg (glass transition point) (° C.) Using a differential scanning calorimeter manufactured by Shimadzu Corporation, a temperature rise of 5 ° C.
The contact point between the base line and the tangent line of the endothermic curve in the vicinity of Tg when measured in / min was defined as Tg.

(3) Composition analysis The resin was hydrolyzed with hydrazine and quantified by liquid chromatography.

(4) Toughness index It was determined by the toughness evaluation method of the above resin.

(5) Fixing temperature (° C.) With a non-magnetic-component printer modified to a variable temperature type,
After forming the test image, the portion having the initial density ID = 1.0 ± 0.3 is passed through a temperature-variable fixing roller. Next, the tape is peeled off from the fixed portion to obtain the density attenuation rate. Further, when the temperature of the roller was increased, the temperature at which the fixing rate exceeded 90% was defined as the fixing temperature. Fusing roller speed is 1
It was set to 00 mm / min and the nip width was set to 8.0 mm for evaluation. A resin having a fixing temperature of 160 ° C. or lower was used as a resin having good fixing properties.

(6) Printing durability A printing durability test was conducted using a copying machine having an actual non-magnetic-component system, and the image change after copying 5000 sheets was visually evaluated. The evaluation was performed by the following method. A: A clear image was obtained from the beginning to the end. B: There was a slight change in the image density on the way, but it was judged to be good throughout. C: Good images were obtained up to the printing durability of 1000 sheets. D: The image deteriorated from the initial stage of the printing durability test.

Example 1 The amounts of terephthalic acid, diol A (polyoxypropylene (2.3) -2,2-bis (4-hydroxyphenyl) propane), pentaerythritol, and ethylene glycol shown in Table 1 were distilled in a distillation column. Was charged into a reaction vessel equipped with. 0.08 parts by weight of dibutyltin oxide as a catalyst was added to all acid components, the internal temperature was 260 ° C., and the stirring rotation speed was 200 r.p.m. p. m. Then, the esterification reaction was carried out under normal pressure for 5 hours. After that, the inside of the reaction system is 1.0 over 30 minutes.
The pressure was reduced to mmHg, the internal temperature was maintained at 240 ° C., and the condensation reaction was carried out for 2 hours while distilling ethylene glycol to obtain a pale yellow transparent resin R-1. Table 2 shows the compositional analysis results and physical properties of the obtained resin.

[0042]

[Table 1]

[0043]

[Table 2]

Next, with respect to 94% by weight of the resin R-1 obtained, carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.) was used.
5% by weight, charge control agent (manufactured by Orient Chemical Industry Co., Ltd.,
1% by weight of Bontron S-34) was premixed with a Henschel mixer, and then using an internal mixer manufactured by Kurimoto Iron Works Co., Ltd. at 150 ° C., 65 r.p.m. p. Melt kneading was performed under the condition of m. After the melt-kneaded product is cooled to room temperature, it is roughly pulverized with a hammer mill and then 20 μm using a jet mill.
Crushed to the following. Then, using a pneumatic classifier manufactured by Nippon Pneumatic Co., Ltd., the particle size is adjusted to 5 to 20 μm, and toner T-
Got 1. The fixing test and the printing durability test of this toner T-1 were carried out using a non-magnetic-component printer modified to a variable temperature type. The test results are shown in Table 3.

[0045]

[Table 3]

From Table 3, it can be seen that when the resin R-1 is used as the toner, the fixing behavior is good and the printing durability is also excellent.

Examples 2 to 3 Resins R-2 to R-3 were obtained in the same manner as in Example 1 except that the composition for polymerization was changed as shown in Table 4. Resin R
Table 5 shows the composition analysis results and physical properties of −2 to R-3.

[0048]

[Table 4]

[0049]

[Table 5]

Next, using the above resins R-2 to R-3,
The same operations as in Example 1 were performed to obtain toners T-2 to T-3. Table 6 shows the fixing test results and printing durability test results of the obtained toners T-2 to T-3.

[0051]

[Table 6]

From Table 6, it is understood that the toners T-2 to T-3 have good fixing property and printing durability.

Examples 4 to 6 Resins R-4 to R-6 were obtained in the same manner as in Example 1 except that the composition for polymerization was as shown in Table 7. Resin R
Table 8 shows the composition analysis results and physical properties of -4 to R-6.

Next, using the above resins R-4 to R-6,
The same operation as in Example 1 was performed to obtain a toner. Table 8 shows the fixing test of the obtained toner and the evaluation result of printing durability.
From Table 8, the toners obtained from the resins R-4 to R-6 are
It can be seen that the fixability and printing durability are good.

[0055]

[Table 7]

[0056]

[Table 8]

Comparative Examples 1 to 4 Resin R-8 was obtained in the same manner as in Example 1 except that the composition for polymerization was as shown in Table 9. Table 10 shows the composition analysis results and the physical properties of the resin R-8. The resin R-
In No. 7, since the amount of diol A used was small, the reaction after reaching the gel point was extremely fast and the reaction could not be controlled. In the resin R-9, the amount of pentaerythritol, which is a polyfunctional alcohol used, was as high as 25 mol% with respect to the total acid components, and therefore the reaction after the gel point could not be controlled. Since the amount of diol A used in Resin R-10 was as large as 80 mol% with respect to the total acid components, the reaction did not proceed to the gel point.

Next, using the above resin R-8, Example 1
The same operation as the above was performed to obtain a toner. Table 10 shows the fixing test of the obtained toner and the evaluation result of printing durability. The amount of aromatic dicarboxylic acid used in the toner is 50 mol% in the acid component.
Since it was as small as the following, Tg and toughness were remarkably lowered, and printing durability was lowered.

[0059]

[Table 9]

[0060]

[Table 10]

Comparative Examples 5 to 6 Resin R- was prepared in the same manner as in Example 1 except that the composition for polymerization and the reaction temperature for esterification were as shown in Table 11.
11 to R-12 were obtained. Table 12 shows the composition analysis results and physical properties of the resins R-11 to R-12.

Next, the same operations as in Example 1 were carried out using the resins R-11 to R-12 to obtain toner. Table 12 shows the fixing test results and the evaluation results of printing durability of the obtained toner.

Since the resin R-11 has a high softening temperature and a high toughness index, the printing durability is very good, but the fixability is extremely lowered. On the contrary, when the softening temperature of resin R-12 is as low as 88 ° C., the fixing property is very good, but the toughness is extremely decreased and the printing durability is decreased.
Further, the cohesive force was drastically reduced, and the non-offset width could not be confirmed.

[0064]

[Table 11]

[0065]

[Table 12]

Comparative Examples 7 to 11 Resin R-1 was prepared in the same manner as in Example 1, except that the composition for polymerization and the reaction temperature for esterification were as shown in Table 13.
3 to R-17 were obtained. Table 14 shows the composition analysis and physical property values of the resins R-13 to R-17.

Next, the same operations as in Example 1 were carried out using the resins R-13 to R-17 to obtain a toner. Table 14 shows the fixing test results and the evaluation results of printing durability of the obtained toner.

Resin R-13 had a low content of terephthalic acid, so that the Tg was lowered and fusion occurred, resulting in poor printing durability. The resin R-14 has a low esterification reaction temperature and is 10
The esterification reaction did not proceed sufficiently even after the reaction for a long time. The resin R-15 had a high molar ratio of the alcohol component charged, so that Tg was lowered, and fusion occurred, resulting in poor printing durability. Resin R-16 had a high Tg and toughness and good printing durability, but the softening temperature increased and the fixability deteriorated. Since the amount of the polyhydric alcohol having a valence of 3 or more used was small, the resin R-17 could not be provided with a sufficient crosslinked structure, and the toughness was lowered and the printing durability was poor.

[0069]

[Table 13]

[0070]

[Table 14]

[0071]

EFFECT OF THE INVENTION The polyester resin for toner of the present invention having the constitution as described above has good fixability, printing durability, non-offset property, blocking resistance, and excellent resin toughness, and particularly high low temperature fixing. It is extremely useful as a toner resin for high-speed copying machines, high-speed printers, and non-magnetic component printers, which require high strength.

Front Page Continuation (72) Inventor Yoichi Nagai 2-1, Ushikawa-dori, Toyohashi City, Aichi Mitsubishi Rayon Co., Ltd. Toyohashi Plant (56) Reference JP-A-4-70670 (JP, A) JP-A-1 -307767 (JP, A) JP 4-70765 (JP, A) JP 2-225520 (JP, A) JP 5-107805 (JP, A) (58) Fields investigated (Int.Cl) . ⁷ , DB name) G03G 9/08-9/087

Claims (2)

(57) [Claims] 1. An (a) acid component containing terephthalic acid as a main component and 60 mol% or more of an aromatic dicarboxylic acid based on the total acid component, and (b) an aliphatic diol and 1 based on the total acid component.
1 to the diol component containing 0 to 60 mol% of the aromatic diol represented by the following formula (I) and (c) the total acid component
A polyester resin composed of 13 mol% of a polyhydric alcohol component having a valence of 3 or more and having a glass transition point Tg of 60 to 60.
A polyester resin for toner, which has a toughness index of 350 to 600 μm at 85 ° C. [Chemical 1] 2. An acid component containing terephthalic acid as a main component and 60 mol% or more of an aromatic dicarboxylic acid based on the total acid component, and 10 to 60 mol% of the following formula based on the aliphatic diol and the total acid component. A diol component containing an aromatic diol represented by (I) and a polyfunctional polyhydric alcohol having a functionality of 1 to 13 mol% based on the total acid component are used, and the molar ratio of the alcohol component to the acid component is 1.3. Mix until 25
After the esterification reaction or transesterification reaction at a temperature of 0 ° C. or higher, the polymerization reaction is performed, and the toughness index is 35.
A method for producing a polyester resin for a toner, which comprises producing a polyester resin having a glass transition point Tg of 0 to 600 μm and a glass transition point Tg of 60 to 85 ° C. [Chemical 2]