JPH107775A - Crosslinked polyester resin, method for producing the same, and toner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crosslinked polyester resin having an appropriate degree of crosslinking and suitable for use as a binder for toner and the like. A crosslinked polyester resin comprising a dicarboxylic acid component having a mole number a, at least one trihydric or higher polyhydric alcohol component having a total mole number b, and a diol component having a mole number c. Wherein Z defined by the following formula (1) is copolymerized in an amount satisfying the following formula (2). Z = f (f−1) b / {(fb + 2c) ² / 2a−2c} (1) 0.8 ≦ Z ≦ 1.3 (2) where f is defined by the following equation (3). Value. _{^{f = Σf i 2 n i /}} Σf i n i (3) However, f _i is the valence of the i-th trihydric or higher polyhydric alcohol component, n _i is the i-th trivalent or more in the total resin Is the number of moles of the polyhydric alcohol component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinked polyester resin suitable for applications such as toner for developing electrostatic images used in the fields of electrophotography, electrostatic recording and electrostatic printing, and a method for producing the same. , And a toner using the same.

[0002]

2. Description of the Related Art Conventional electrophotography is disclosed in US Pat.
As described in US Pat. No. 7691 and US Pat. No. 2,357,809, an electrostatic image is formed on the surface of a roller made of a photoconductive insulator, and this is formed into a toner by a dry developer made of a colored fine powder. The image forming apparatus includes a developing step of developing an image as an image, a transfer step of transferring the obtained toner image to a transfer sheet such as paper, and a fixing step of performing permanent fixing by heating, pressing, or the like.

In recent years, there has been an increasing demand for speeding up, miniaturization, and energy saving in copiers. As a fixing step to meet such demands, a heat roller fixing method which has high heat efficiency, has a compact mechanism, and can operate at high speed. The system is preferably used.

However, in the heating roller fixing method, since the surface of the heating roller and the toner image surface come into contact with each other, the toner is transferred to the surface of the heating roller, and this is transferred to the next paper to be stained. This causes a so-called offset phenomenon.

In order to prevent such an offset phenomenon, Japanese Patent Publication No. 51-23354 proposes using a styrene-based crosslinked resin as a resin for toner. Since then, in the heat roller fixing method, a styrene-acrylic acid ester copolymer has been mainly used as a resin for toner while undergoing various improvements.

On the other hand, recently, a polyester resin can be fixed at a lower temperature, and a fixed toner image has excellent durability against a vinyl chloride plasticizer.
They have been found to be superior to conventional styrene-acrylic acid ester copolymers and the like in that they have excellent transparency and can cope with colorization, and are attracting attention as resins for toner binders.

In general, a polyester resin is produced by a condensation reaction between a dihydric carboxylic acid and / or a lower ester thereof and a dihydric alcohol. When used as a resin for toner, the offset resistance is extremely poor, and a good transferred image cannot be obtained.

In order to improve this point, a polyester resin is provided with a branched or cross-linked structure, and polyester resins obtained by copolymerizing a polyfunctional component are widely known.

[0009]

However, if the amount of the polyfunctional component is increased, the viscosity of the resin becomes remarkably high, so-called gelation is easily caused, and the processability of the resin such as solvent solubility is lost. In the first place, solidification occurs in the polymerization apparatus, which may result in inability to pay out or damage to the apparatus. On the other hand, if gelation is to be avoided, it is necessary to reduce the amount of the polyfunctional component or to dispense the resin at an early stage of the reaction process. But does not function sufficiently as a binder for toner. As described above, conventionally, if the performance of the resin is to be improved, the risk of gelation must be borne, and it has been difficult to stably produce a crosslinked polyester resin.

As a countermeasure, Japanese Patent Application Laid-Open No. 3-54574 discloses a method for controlling a rapid gelling reaction by controlling a reaction temperature and a degree of vacuum. However, in this method, there is a problem that the viscosity of the polymer is excessively increased due to the distillation of a low-boiling component generated by a transesterification reaction, and a resin having a desired degree of crosslinking cannot be obtained.

On the other hand, JP-A-2-225520 discloses that a low-molecular-weight linear polyester having a number average molecular weight (Mn) of 300 or more and 1400 or less or having a side chain is copolymerized with a trivalent or higher valent component. Although a method for forming crosslinks is disclosed, it is still unavoidable that the viscosity of the polymer sharply increases.

Further, JP-A-62-45622 discloses that a polyester resin contains a monocarboxylic acid,
Although a method of controlling the degree of crosslinking of the polyester resin has been proposed, it has not yet achieved sufficient production stability.

An object of the present invention is to provide a crosslinked polyester resin having an appropriate degree of crosslinking and suitable for uses such as a binder for toner, and a polymerization method for stably producing the same.

[0014]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by controlling the parameters calculated from the composition within a specific range, the polyester resin has an appropriate degree. The present inventors have found that a degree of branching can be imparted and that polymerization can be stably performed, and the present invention has been accomplished.

That is, the present invention relates to a crosslinked polyester resin comprising a dicarboxylic acid component, at least one trihydric or higher polyhydric alcohol component, and a diol component, which is defined by the following formula (1). Z is the following equation (2)
Is a crosslinked polyester resin characterized by being made of a polyester copolymerized in an amount satisfying the following.

Z = f (f−1) b / {(fb + 2c) ² / 2a−2c} (1) 0.8 ≦ Z ≦ 1.3 (2) where a is the number of moles of the dicarboxylic acid component, b is the total number of moles of the trihydric or higher polyhydric alcohol component, c is the number of moles of the diol component, and f is a value defined by the following formula (3).

[0017] ^{_{f = Σf i 2 n i /}} Σf i n i (3) However, f _i is the valence of the i-th trihydric or higher polyhydric alcohol component, n _i is the i-th in the total resin It is the number of moles of the trihydric or higher polyhydric alcohol component.

The above equation (1) is an empirical equation based on the expected value of polymer chain branching defined by PJ Flory, and Z is a parameter for quantifying the branching state of the resin. Further, f defined by the formula (3) is a weight average functional group number of the alcohol component having a valence of 3 or more.

The present invention also relates to a crosslinked polyester resin comprising a dicarboxylic acid component and at least one trihydric or higher polyhydric alcohol component, wherein Z defined by the following formula (4) is represented by the following formula: It is a crosslinked polyester resin characterized by being made of a polyester copolymerized in an amount satisfying (2).

Z = f (f−1) b / (fb ² / 2a) (4) 0.8 ≦ Z ≦ 1.3 (2) where a is the number of moles of the dicarboxylic acid component, and b is trivalent. The sum of the number of moles of the polyhydric alcohol component, f, is a value defined by the following equation (3).

[0021] ^{_{f = Σf i 2 n i /}} Σf i n i (3) However, f _i is the valence of the i-th trihydric or higher polyhydric alcohol component, n _i is the i-th in the total resin It is the number of moles of the trihydric or higher polyhydric alcohol component.

Further, the present invention is characterized in that when producing the above-mentioned crosslinked polyester resin, except for the water produced by the esterification reaction or the lower alcohol produced by the transesterification reaction, it is not substantially diffused out of the system.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The most important point in the present invention is to control polymerization conditions based on the composition. As a result of extensive studies by the present inventors, a composition capable of stably producing a polyester resin having an appropriate degree of cross-linking has a Z value calculated by equation (1) as shown in equation (2) above. Is 0.8 or more and 1.3
It is to become. A polyester resin satisfying this condition not only has a gel amount that can be suitably used for various applications, but also increases viscosity to some extent in the manufacturing process, but is within a level that can be stirred and discharged. There are features. When the Z value exceeds 1.3, a remarkable gel component is formed as in the prior art, and it becomes impossible not only to discharge the reactant from the polymerization apparatus, but also to cause the solidified resin to react with the reaction apparatus. This causes problems such as damaging the device. In addition, such highly crosslinked polyester resin has an extremely high melt viscosity, is insoluble in general-purpose solvents,
This causes problems with workability such as difficulty in pulverization, and makes it impossible to use for general applications. When the Z value is less than 0.8, the resin does not have a sufficient molecular weight and a crosslinked structure, and when used for an application such as a binder for a toner, various properties such as heat resistance, strength, and adhesiveness. Is significantly inferior.

In order to keep the Z value within a certain range throughout the polyester polymerization step according to the present invention, water other than water produced by the esterification reaction or a lower alcohol derived from a lower alkyl ester of dicarboxylic acid is substantially charged. Conditions such as temperature and pressure must be selected so that the monomer does not escape out of the system. To do this,
It is desirable that the monomer used has a boiling point as high as possible or does not boil under actual reaction conditions. Alternatively, the monomers may be determined first, and a polycondensation temperature lower than their boiling points may be selected and used.
Also, if there is a facility such as a condenser that can select and control substances to be distilled out of the system, these limitations will be reduced, and the range of choice between monomers and reaction conditions will be expanded. Needless to say. In practice, use a monomer with a higher boiling point than the one to be distilled, such as water or a lower alcohol,
An esterification reaction apparatus equipped with a falling condenser capable of controlling the temperature may be used. It is convenient to set the condenser to a temperature higher than the boiling point of the distillate and to use a normal esterification reaction temperature at normal pressure.

The dicarboxylic acid component used in the present invention includes, as aliphatic dicarboxylic acids, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n
-Octenyl succinic acid, n-octyl succinic acid, and anhydrides or lower alkyl esters of these acids. As the alicyclic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, hydrogenated 2,2
Examples thereof include 6-naphthalenedicarboxylic acid and anhydrides or lower alkyl esters of these acids. Examples of the aromatic dicarboxylic acid further include phthalic acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-methylenedibenzoic acid, and anhydrides or lower alkyl esters of these acids. Can be. As the lower alkyl group constituting the lower alkyl ester, a methyl group having 1 to 4 carbon atoms, an ethyl group, an n-propyl group, an isopropyl group, an n-
Butyl group, isobutyl group, sec-butyl group, tert
-Butyl group and the like.

As the polyhydric alcohol component having a valency of 3 or more, which gives a crosslinked portion to the resin, trihydric to hexahydric alcohols are preferable. For example, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan Pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol , Trimethylolethane, trimethylolpropane,
Examples include 1,3,5-trihydroxymethylbenzene, and one or more components can be used.

Examples of the diol component include ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 2-butene-1,
4-diol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, pentaethylene glycol, 1,2-
Propanediol, 1,2-butanediol, 1,3-
Butanediol, 2,3-butanediol, neopentyl glycol, 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 1,4-cyclohexanedimethanol, 1,4-dihydroxycyclohexane, hydrogenated bisphenol A, cyclohexylethylene glycol, 1,2-dicyclohexylethylene glycol, p-xylylene glycol, m -Xylylene glycol, various etherified bisphenol A, etc., and any of them can be suitably used.

If the above formula (4) is satisfied, the diol component may not be used in some cases.

In the polymerization method of the present invention, all ordinary polymerization conditions for polyester can be used as long as the monomer does not escape out of the system as described above. The polymerization temperature, the degree of pressure reduction, the type and amount of the catalyst, the use of additives and the like are not particularly limited. As a production apparatus, any general-purpose ester polymerization apparatus can be suitably used, but it is more preferable that the above-mentioned condenser is provided.

The toner of the present invention is obtained by using the above-mentioned crosslinked polyester resin of the present invention. Specifically, the toner is obtained by mixing a colorant with the crosslinked polyester resin. In order to produce the toner of the present invention, a coloring agent and various additives as necessary are blended into a resin for a toner containing the crosslinked polyester resin of the present invention as a main component, mixed by a ball mill or the like, and kneaded. The respective steps of pulverization and classification may be performed.

The particle size of the toner of the present invention is 1 to 50 μm,
Preferably, the thickness is 5 to 30 μm. As the colorant contained in the toner of the present invention, all known colorants can be used, and carbon black, nigrosine dye, benzidine yellow, quinacridone, rhodamine B, phthalocyanine blue, aniline blue, calco oil blue, chrome yellow, ultramarine blue , Methylene blue, rose bengal and the like, or a mixture thereof.

The additives to be added as required include:
Examples include a charge control agent and a magnetic substance. Examples of the charge control agent include a positive charge control agent such as a nigrosine dye, a triphenylmethane dye containing a tertiary amine as a side chain, a quaternary ammonium salt compound, and a polyamine resin. As the negative charge control agent,
Examples thereof include metal-containing azo dyes, copper phthalocyanine dyes, and metal complexes of alkyl derivatives of salicylic acid. These charge control agents are used in an amount of 0.1 to 8.0% by weight, preferably 0.2 to 8.0% by weight based on the toner binder resin.
5.0% by weight is blended.

In addition to the charge control agent and the like, an anti-offset agent such as wax and a fluidity improver such as hydrophobic silica can be considered as a property improver. However, when the crosslinked polyester resin of the present invention is used, The effect of property improvement can be obtained without adding these property improvers, and even when added, the amount of addition may be smaller than usual.

The toner of the present invention is usually made into a two-component developer by mixing with a carrier such as iron powder.
The mixing ratio is 0.3 to 2 with respect to 100 parts by weight of the carrier.
0 parts by weight is preferred. When the toner of the present invention contains a magnetic material, it is used as a one-component developer as it is, and when it does not contain a magnetic material, it is used as a non-magnetic one-component developer for developing an electrostatic image.

[0035]

Embodiments of the present invention will be described below. The evaluation of the physical properties of the resin and the properties of the toner obtained using the same were performed by various measuring methods and evaluation methods described below.

Solvent solubility: The obtained polyester is
Acetone, 1,4-dioxane, chloroform, phenol / 1,1,2,2-tetrachloroethane (1/1 weight ratio)
A test was conducted in which the solvent was dissolved at a concentration of 1 g / 100 ml in four kinds of solvents including a mixed solvent (hereinafter, referred to as a “mixed solvent”).
That is, the state of the solution after charging the resin into the solvent and stirring at room temperature for 2 hours was visually evaluated.

When dissolved in 1,4-dioxane,
Using this as a solvent, the acid value was measured by a method according to JIS0070 (however, Examples 7 and 8 and Comparative Example 6 were excluded). When dissolved in a mixed solvent, the relative viscosity was measured under the conditions of 20 ° C. and 0.5 g / 100 ml using this as a solvent.

Then, the case of complete dissolution was evaluated as 場合, and the case of insoluble matter was evaluated as x.

Composition analysis: ¹ H-NMR method and gas chromatography were used. In the former method, the resin was dissolved in deuterated chloroform, and the composition ratio was determined from the integral value ratio of protons. For resins that have gelled and become insoluble,
The measurement was carried out after previously solubilizing by glycolysis with a known amount of triethylene glycol. In the latter method, after the resin was subjected to methanolysis or saponification, the resin was subjected to gas chromatography, and each component was quantified from a calibration curve prepared using known data to determine the composition ratio. -Pulverizability of resin: Resin which passed the usual pulverization process was sieved to obtain a resin powder which passed 16 mesh but not 20 mesh. This classified resin powder is
0.0g precisely weighed (W1), coffee mill (PHI)
After grinding for 15 seconds by HR-2170 type (manufactured by LIPS), the mixture was sieved through a 32 mesh sieve, and the weight W2 (g) of the resin that did not pass was precisely weighed, and the residual ratio (%) was determined according to the following equation.

Residual rate (%) = W 2 (g) / W 1 (g) × 100 The above operation was performed three times, and 場合, 15.1 to 30.0 when the average residual rate was 0 to 15.0%. % For 3%
The case of ４５45.0% was evaluated as Δ, and the case of 45.1% to 100% was evaluated as ×. -Blocking resistance: toner at 50 ° C, relative humidity 40%
Was observed for 48 hours when left under the above conditions. Then, a case where no aggregate was observed was evaluated as ○, a case where some aggregate was generated was evaluated as Δ, and a case where an aggregate was significantly observed was evaluated as ×. Offset occurrence temperature (° C.): 4 parts by weight of each electrophotographic toner obtained in each of the following Examples and Comparative Examples, and 96 parts by weight of a ferrite carrier without a resin coating (FL-1530 manufactured by Powder Tech). Was mixed to prepare a two-component developer. Next, using this developer, a plurality of unfixed belt-shaped images of 2 cm long and 5 cm wide were formed on A4 size transfer paper using a commercially available copying machine (BD-9110 manufactured by Toshiba Corporation). Next, a fixing device in which a heat fixing roller having a surface layer formed of Teflon (trade name of polytetrafluoroethylene: registered trademark) and a pressure fixing roller having a surface layer formed of silicone rubber are rotated in pairs is used as a roller. Pressure 1kg / cm ² and roller speed 200m
m / sec., and the surface temperature of the heat fixing roller is increased step by step.
A strip image of 5 cm in width and 5 cm in width was copied. Then, an observation is made as to whether or not an offset stain occurs in the margin of the transfer paper, and the minimum surface temperature of the heat-fixing roll when the stain occurs is defined as an offset occurrence temperature (° C.), and the anti-offset evaluation is performed. And Minimum fixing temperature (° C.): A fixed image formed by the above-mentioned fixing machine was rubbed with an edge of a sand eraser rubber having a width of 15 mm on which a load of 1 kg was applied, and a fixing rate was calculated according to the following equation. . Then, the temperature (° C.) of the fixing roller when the fixing rate exceeded 70% was defined as the minimum fixing temperature. In addition,
The image density was measured using a reflection densitometer (RD-91 manufactured by Macbeth).
It measured using 4). Fixing rate (%) = [image density of fixed image after rubbing / image density of fixed image before rubbing] × 100

Transfer resistance of transfer paper: A copy test was performed with each of the above-mentioned developers and a fixing machine (the surface temperature of the heat fixing roller was set at 170 ° C.), and the transfer paper was wrapped around the heat fixing roller. Sex evaluation was performed. When 50 sheets of the transfer paper were continuously inserted into the transfer machine, the case where the winding around the heat fixing roller did not occur was evaluated as ○, and the case where the winding occurred on one or more sheets of transfer paper was evaluated as ×. Example 1 100 moles of terephthalic acid and trimethylolpropane 2
0 mol and 90 mol of triethylene glycol were placed in a glass reactor equipped with a thermometer, a stainless steel stirrer, and a falling condenser (temperature setting: 120 ° C.). 250 ° C, stirring speed 200r.
The reaction was performed at pm. Then, esterification starts,
Distillation of water started from the reaction system. At this time, the stirring torque value was 0 kg-cm. After about 4 hours, the stirring torque increased to 3.5 kg-cm. The reaction was continued for about 1 hour until the distillation of water was completed, but the stirring torque value remained constant. In the ¹ H-NMR analysis of the distillate, components other than water were not detected. When a solubility test was performed on the obtained polyester resin, insolubles were found in acetone, but all were dissolved in the other three solvents. The acid value was 0.45 mgKOH / g and the relative viscosity was 1.30. When the composition of the obtained resin was analyzed, the molar ratio of the terephthalic acid component, the trimethylolpropane component, and the triethylene glycol component did not deviate from the charged composition. Examples 2 to 8 Further, a polyester having another composition was produced in the same manner as in Example 1. However, in Example 8, no diol component was blended. In each case, the stirring torque showed a constant value when the reaction water almost distilled out of the system. Tables 1 and 2 show these results together with the results of Example 1. Since all were dissolved in three solvents other than acetone, the acid value and the relative viscosity were measured. The resin composition was examined in the same manner as in Example 1.
There was no discrepancy with the preparation composition.

[0042]

[Table 1]

[0043]

[Table 2]

Example 9 100 mol of dimethyl terephthalate and trimethylol
20 moles of lopan and 90 moles of triethylene glycol
In the same manner as in Example 1, a thermometer and a stainless steel stirrer
And a falling condenser (temperature setting 100 ° C)
Placed in a glass reactor, and heated to an internal temperature of 2 in a nitrogen gas atmosphere.
The reaction was carried out at 50 ° C. and a stirring rotation speed of 200 rpm. Do
And transesterification is started, and methanol
Distillation has begun. At this time, the stirring torque value is 0 kg-cm.
Indicated. After about 4 hours, the stirring torque was 3.4.
kg-cm. Further distillation of methanol ends
The reaction was continued for about 1 hour until the stirring torque was constant.
Up to. Also the distillate ¹In H-NMR analysis, meta
No components other than knol were detected. Total distilling methanow
199 moles of dimethyl terephthalate.
99.5 percent of the theoretical distillate calculated from
Was. A solubility test was performed on the obtained polyester resin.
When I went, I found insolubles in acetone, but other
All were dissolved in the three solvents. The relative viscosity was 1.29.
Was. No deviation from the preparation was observed in the composition analysis. Example 10 A polyester having another composition was produced in the same manner as in Example 9.
went. When methanol distillation is completed (theoretical distillation amount
At the time when 99.3% of the
Indicates a constant value. The results of Examples 7 and 8 are also shown in Table 1.
And Table 2. This embodiment 8 also uses acetone or less.
Since it was dissolved in the other three solvents, the relative viscosity was measured. this
The resin composition was the same as in the preparation. Comparative Example 1 100 moles of terephthalic acid and trimethylolpropane 2
0 mol and 75 mol of triethylene glycol
The same reactor as in Example 1 was charged, and under a nitrogen gas atmosphere,
The reaction was carried out at a temperature of 250 ° C. and a stirring rotation speed of 200 rpm.
At this time, the stirring torque value was 0 kg-cm. Where Z
The value was 1.70, which was outside the range of Expression (2). So
And esterification starts, and water distilling starts from the reaction system
Was. Then, the reaction was carried out for about 3 hours. Continued reaction
However, after about one hour, the polymerized polymer gels.
It awakened and became unable to stir. Normal payout is not possible
Therefore, the glass container was destroyed and the resin was discharged.
The resin was insoluble in all four solvents. Composition analysis
No deviation from the preparation was observed. Comparative Example 2 100 moles of terephthalic acid and trimethylolpropane 5
0 mol and 45 mol of triethylene glycol
The same reactor as in Example 1 was charged, and under a nitrogen gas atmosphere,
The reaction was carried out at a temperature of 250 ° C. and a stirring rotation speed of 200 rpm.
At this time, the stirring torque value was 0 kg-cm. Where Z
The value was 1.52, which was outside the range of Expression (2). So
And esterification starts, and water distilling starts from the reaction system
Was. Then, the reaction was carried out for about 3 hours. Continued reaction
However, after about 2 hours, the polymerized polymer gels.
It awakened and became unable to stir. Normal payout is not possible
Therefore, the glass container was destroyed and the resin was discharged.
The resin was insoluble in all four solvents. Composition analysis
No deviation from the preparation was observed. Comparative Example 3 100 mol of terephthalic acid and trimethylolpropane 2
0 moles and 110 moles of triethylene glycol
As in Example 1, a thermometer, a stainless steel stirrer,
Into a reactor equipped with a condenser
The reaction was carried out at an internal temperature of 250 ° C and a stirring rotation speed of 200 rpm.
Was. At this time, the stirring torque value was 0 kg-cm. Was
However, the Z value was 0.70, which was less than the range of Expression (2).
Was. Then esterification starts, and water distills out of the reaction system.
Start and then react for about 4 hours
went. The reaction continued further, but after about 5 hours
Even though the stirring torque value remains at 0 kg-cm,
The degree did not rise. This resin dissolves in all four solvents
did. The acid value is 0.10mgKOH / g and the relative viscosity is 1.07
there were. No deviation from the preparation was found in the composition analysis
Was. Comparative Example 4 100 moles of isophthalic acid and pentaerythritol 30
With 2 moles of bisphenol A ethylene oxide
In the same manner as in Example 1, a thermometer and a stainless steel
Reactor equipped with loess stirrer and falling condenser
In a nitrogen gas atmosphere, the internal temperature is 250 ° C,
The reaction was performed at 200 rpm. At this time, the stirring torque value
Showed 0 kg-cm. However, the Z value is 0.62, and the equation
It was less than the range of (2). And esterification begins
Distilling off water from the reaction system, and then
The reaction was carried out for about 4 hours until completion. Continued reaction
However, even after about 5 hours, the stirring torque value is 0kg-cm
As it was, the melt viscosity of the reaction system did not increase. This tree
The fat was dissolved in all four solvents. Acid value is 0.10mgKOH /
g and the relative viscosity were 1.05. In composition analysis,
No deviation was found. Comparative Example 5 100 mol of dimethyl terephthalate and trimethylol
20 moles of lopan and 75 moles of triethylene glycol
Was charged into the same reactor as in Example 1, and a nitrogen gas atmosphere
The reaction was carried out at an internal temperature of 250 ° C. and a stirring rotation speed of 200 rpm.
went. At this time, the stirring torque value was 0 kg-cm.
However, the Z value is 1.70, which exceeds the range of Expression (2).
Was. Then esterification started, and methanol
Then, the reaction was carried out for about 3 hours. Sa
When the reaction was continued for about 1 hour,
The limer gelled and became unable to stir. Normal payment
Since it was impossible to go out, the glass container was destroyed
The fat was dispensed. This resin is insoluble in all four solvents
occured. Comparative Example 6 100 mol of dimethyl terephthalate and trimethylol
Lopan 20 mol and triethylene glycol 110 mol
Was charged into the same reactor as in Example 1, and the nitrogen gas atmosphere was
Reaction at 250 ° C internal temperature and stirring speed of 200 rpm
Was done. However, the Z value is 0.70, which is the range of the equation (2).
It was less than surrounding. At this time, the stirring torque value is 0 kg-cm.
Indicated. Then esterification begins, and methano
Distillation of methanol starts, and then distillation of methanol ends.
The reaction was continued for about 4 hours until Methanol distillate is theoretical
99.3% of the amount. He continued the reaction,
After about 5 hours, the stirring torque value remains at 0kg-cm
As a result, the melt viscosity of the reaction system did not increase. This resin is 4
Dissolved in all seed solvents. The relative viscosity is 1.08
Was.

The results of Comparative Examples 1 to 6 are shown in Tables 1 and 2. As shown in Tables 1 and 2, when the Z value is within the range of the present invention, the stirring torque becomes stable at a certain constant value and the relative viscosity is relatively high within a range not causing gelation. Was obtained, and a resin having good toner characteristics was obtained. On the other hand, when the Z value is out of the range of the present invention, gelation that cannot be performed in a normal dispensing mode occurs, and a toner that cannot be used as a toner binder is generated, or a torque increase is detected in a reaction process. Only a resin having such low viscosity as to be impossible and having low performance for the above-mentioned applications was obtained.

Next, toners were produced using the resins of Examples 1 to 10 and Comparative Examples 1 to 6, respectively. That is, 100 parts by weight of each polyester resin and carbon black (trade name: MA-100, manufactured by Mitsubishi Chemical Industry Co., Ltd.)
5 parts by weight, 2 parts by weight of a chromium-containing metal dye (trade name: S-34, manufactured by Orient Chemical Industry Co., Ltd.) and polypropylene (trade name, manufactured by Sanyo Chemical Industry Co., Ltd .; Viscol 33)
OP) and 2 parts by weight were mixed with a super mixer. And this is melt-kneaded by a twin screw extruder, and after cooling,
The particles were roughly pulverized by a hammer mill, finely pulverized by a jet mill, and then adjusted in particle diameter by a classifier to obtain a toner having an average particle diameter of 11 μm.

Next, 96 parts by weight of a ferrite carrier was added to 4 parts by weight of the obtained toner to prepare a developer, and the toner characteristics were evaluated using the developer. Table 3 shows the evaluation results of the pulverizability of the resin and the characteristics of the toner during the production of the toner.

[0048]

[Table 3]

As can be seen from the results in Table 3, all of the resins obtained in Examples 1 to 10 had good pulverizability. Further, the toners using the resins of Examples 1 to 10 are:
All of them exhibit particularly excellent toner characteristics in terms of blocking resistance, low-temperature fixing property, offset resistance, and winding resistance, and can form a high-speed good image stably regardless of environmental conditions. Was.

On the other hand, each of the resins obtained in Comparative Examples 1 to 6 and each of the toners using the resins were inferior in at least one of the above characteristics.

[0051]

As described above, according to the present invention, a crosslinked polyester resin suitable as a toner binder can be obtained without gelation, and a toner using this crosslinked polyester resin can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naomi Sasaki 23, Uji Kozakura, Uji-city, Kyoto Unitika Co., Ltd. Central Research Institute, Inc. In the Tomagawa Paper Mill Technical Research Laboratory

Claims (7)

[Claims] 1. A crosslinked polyester resin comprising a dicarboxylic acid component, at least one trihydric or higher polyhydric alcohol component, and a diol component, wherein Z defined by the following formula (1) is A crosslinked polyester resin comprising a polyester copolymerized in an amount satisfying the formula (2). Z = f (f−1) b / {(fb + 2c) ² / 2a−2c} (1) 0.8 ≦ Z ≦ 1.3 (2) where a is the number of moles of the dicarboxylic acid component, and b is three The total number of moles of the polyhydric alcohol component having a valency or higher, c is the number of moles of the diol component, and f is a value defined by the following formula (3). _{^{f = Σf i 2 n i /}} Σf i n i (3) However, f _i is the valence of the i-th trihydric or higher polyhydric alcohol component, n _i is the i-th trivalent or more in the total resin Is the number of moles of the polyhydric alcohol component. 2. The crosslinked polyester resin according to claim 1, wherein the crosslinked polyester resin does not substantially contain a dioxane-insoluble component or a chloroform-insoluble component. 3. A crosslinked polyester resin comprising a dicarboxylic acid component and at least one trihydric or higher polyhydric alcohol component, wherein Z defined by the following formula (4) is represented by the following formula (2): A crosslinked polyester resin comprising a polyester copolymerized in an amount satisfying the following. Z = f (f-1) b / (fb ² / 2a) (4) 0.8 ≦ Z ≦ 1.3 (2) where a is the number of moles of the dicarboxylic acid component, and b is polyvalent or higher. The total number of moles of the dihydric alcohol component, f, is a value defined by the following equation (3). _{^{f = Σf i 2 n i /}} Σf i n i (3) However, f _i is the valence of the i-th trihydric or higher polyhydric alcohol component, n _i is the i-th trivalent or more in the total resin Is the number of moles of the polyhydric alcohol component. 4. The crosslinked polyester resin according to claim 3, which is substantially free of dioxane-insoluble components or chloroform-insoluble components. 5. In producing a crosslinked polyester resin comprising a dicarboxylic acid component, at least one trihydric or higher polyhydric alcohol component and a diol component, Z defined by the following formula (1) is as follows: A crosslinked polyester resin which is copolymerized in an amount that satisfies the formula (2) and does not substantially dissipate out of the system except for water produced by an esterification reaction or lower alcohol produced by a transesterification reaction. Manufacturing method. Z = f (f−1) b / {(fb + 2c) ² / 2a−2c} (1) 0.8 ≦ Z ≦ 1.3 (2) where a is the number of moles of the dicarboxylic acid component, and b is three The total number of moles of the polyhydric alcohol component having a valency or higher, c is the number of moles of the diol component, and f is a value defined by the following formula (3). _{^{f = Σf i 2 n i /}} Σf i n i (3) However, f _i is the valence of the i-th trihydric or higher polyhydric alcohol component, n _i is the i-th trivalent or more in the total resin Is the number of moles of the polyhydric alcohol component. 6. When producing a crosslinked polyester resin comprising a dicarboxylic acid component and at least one trihydric or higher polyhydric alcohol component, Z defined by the following formula (4) is replaced by the following formula (2) A) producing a crosslinked polyester resin, characterized in that, except for the water produced by the esterification reaction or the lower alcohol produced by the transesterification reaction, it is not substantially dissipated to the outside of the system, while copolymerizing in an amount satisfying the above. Z = f (f-1) b / (fb ² / 2a) (4) 0.8 ≦ Z ≦ 1.3 (2) where a is the number of moles of the dicarboxylic acid component, and b is polyvalent or higher. The total number of moles of the dihydric alcohol component, f, is a value defined by the following equation (3). _{^{f = Σf i 2 n i /}} Σf i n i (3) However, f _i is the valence of the i-th trihydric or higher polyhydric alcohol component, n _i is the i-th trivalent or more in the total resin Is the number of moles of the polyhydric alcohol component. 7. A toner comprising the crosslinked polyester resin according to claim 1. Description: