JP2000066447A - Polyester resin for toner and the toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve blocking resistance, melt flowability, low temp. fixability and electrostatic charge characteristics even at high humidity by using a specified polyester resin having a specified content of a polyhydric alcohol. SOLUTION: This polyester resin contains 50-100 mol.% aliphatic diol and 10-60 mol.% arom. diol of the formula, based on the amt. of all the acid components. In the formula, R is >=3C alkylene and (x) and (y) are numbers satisfying 2.0<=x+y<=7.0. The content of a polyhydric alcohol in the polyester resin is 3-15 mol.% in the case of a trihydric alcohol and 0.5-2.5 mol.% in the base of a tetrahydric alcohol, based on the amt. of all the acid components. The polyester resin has 120-160 deg.C softening temp., 0.5-10 mgKOH/g acid value and 55-70 deg.C glass transition temp. The toner for developing an electrostatic charge image contains the polyester resin as a binder.

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 or the like, and a polyester resin as a binder. More specifically, the toner used is excellent in blocking resistance, melt fluidity, low-temperature fixability and charging characteristics even under high humidity, and is particularly useful for high-speed copying machines and high-speed printers that require high printing durability. The present invention relates to a polyester resin for a toner and a toner.

[0002]

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

The toner used in the dry development system includes a one-component toner and a two-component toner. The two-component toner is first melt-kneaded with a resin, a colorant, a charge control agent and other necessary additives and sufficiently dispersed, then coarsely pulverized, then finely pulverized and classified into a predetermined particle size range. Manufactured. The one-component toner is similarly manufactured by adding magnetic iron powder in addition to the components of the two-component toner.

[0004] The resin used as the binder is the main component in the compounding of the toner and therefore controls most of the performance required for the toner. For this reason, the resin for the toner is required to have good dispersibility of the colorant in the melt-kneading step in the production of the toner, good pulverizability in the pulverizing step, and the like. Versatile performance such as good blocking resistance and good electrical properties is required. Epoxy resins, polyester resins, polystyrene resins, methacrylic resins, and the like are known as resins used in the production of toners, but a copolymer of styrene and (meth) acrylic acid ester is mainly used for the pressure fixing method. I have been. However, polyester resins have attracted attention in recent years because of their ability to be fixed at lower temperatures and the excellent PVC resistance of the fixed toner images.

[0005] In polyester resin for toner, Japanese Patent Publication No.
As proposed in JP-A-31886, co-condensation of a trivalent or higher polyhydric alcohol with a trivalent or higher polyhydric carboxylic acid to have a crosslinked structure imparts offset resistance in a fixing step, This is effective from the viewpoint that good electrical characteristics can be obtained. However, a conventional polyester resin obtained by co-condensation of a trihydric or higher alcohol has a problem in that the image quality changes depending on humidity due to insufficient moisture resistance, and the strength of the toner is insufficient. Therefore, there is a disadvantage that the toner is pulverized due to long-term running and the electrical characteristics are changed, and improvement thereof has been strongly desired.

[0006]

Accordingly, in order to improve the moisture resistance and fixing performance of the polyester resin, a long-chain aliphatic dicarboxylic acid or a dicarboxylic acid having a long-chain aliphatic side chain is used together with a trihydric or higher polyhydric alcohol. To introduce a long-chain aliphatic hydrocarbon unit into the main chain or side chain, as disclosed in JP-A-62-78568 and JP-A-62-78568.
-178278, JP-A-63-128358, JP-A-63-128359, and JP-A-1-11
3761 publication. However, in these polyester resins, sebacic acid or the like is used as a long-chain aliphatic dicarboxylic acid, and dodecenylsuccinic acid or the like is used as a dicarboxylic acid having a long-chain aliphatic side chain. Although the carbon number of becomes large, the moisture resistance and fixing performance of the toner are improved,
Glass transition temperature of polyester resin (hereinafter abbreviated as Tg)
And the toner has poor blocking resistance and resin strength.

Japanese Patent Application Laid-Open No. Hei 7-160045 discloses a technique for improving the fixing performance of a polyester resin.
It has been proposed that adipic acid be co-condensed as an aliphatic dicarboxylic acid together with a trihydric or higher polyhydric alcohol to introduce an aliphatic dicarboxylic acid into the main chain. However, such polyesters have a large co-condensation amount of trihydric or higher polyhydric alcohols, so that the Tg of the polyester resin is lowered and the resin strength is insufficient, and the printing durability of the toner is insufficient. Had.

Accordingly, an object of the present invention is to provide a high-speed copier and a high-speed copying machine which are required to have excellent blocking resistance, melt fluidity, low-temperature fixability and charging characteristics even under high humidity, and particularly require high printing durability. An object of the present invention is to provide a polyester resin for a toner and a toner useful for a printer.

[0009]

The present inventors have conducted intensive studies to overcome the above-mentioned problems of the prior art, and as a result, have found that a specific amount of a linear aliphatic dicarboxylic acid having a specific carbon number is used. In addition, the inventors have found that a polyester resin obtained by using a specific amount of a trihydric or higher polyhydric alcohol can achieve the object as a binder resin for a toner, and have reached the present invention.

That is, the polyester resin for a toner of the present invention comprises (a) 90 to 99.5 mol% based on all acid components.
A terephthalic acid component or a lower alkyl ester thereof and / or an isophthalic acid component or a lower alkyl ester thereof; Component or lower alkyl ester or acid anhydride thereof,
(C) a trihydric or tetrahydric polyhydric alcohol component, (d) 50 to 100 mol% of an aliphatic diol component relative to the total acid component, and (e) 10 to 60 mol% of a total acid component. A polyester resin composed of an aromatic diol component represented by (I), wherein the content of the polyhydric alcohol component (c) is 3 to 3 with respect to the total acid component in the case of a trihydric alcohol component. 15 mol%, 0.5 to 2.5 mol% with respect to the total acid component in the case of a tetrahydric alcohol component,
Softening temperature 120-160 ° C, acid value 0.5-10mg
KOH / g and a glass transition temperature (Tg) of 55 to 70 ° C.

[0011]

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(In the formula, R represents an alkylene group having 3 or less carbon atoms, and X and Y are numbers satisfying the following formula: 2.0 ≦ X + Y ≦ 7.0.) The developing toner is characterized by containing the polyester resin as described above as a binder.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester resin of the present invention comprises
(A) a terephthalic acid component and / or an isophthalic acid component, (b) a linear aliphatic dicarboxylic acid component having 8 or less carbon atoms, (c) a trihydric or higher polyhydric alcohol component, (d) an aliphatic diol component, (D) It comprises an aromatic diol component represented by the formula (I).

[0014]

Embedded image

(In the formula, R represents an alkylene group having 3 or less carbon atoms, and X and Y are numbers satisfying the formula: 2.0 ≦ X + Y ≦ 7.0.) In the present invention, the polyester resin is constituted. The terephthalic acid component and / or isophthalic acid component (a) used for this purpose is composed of terephthalic acid, isophthalic acid and lower alkyl esters thereof. Examples of lower alkyl esters of terephthalic acid and isophthalic acid include, for example, dimethyl terephthalate, dimethyl isophthalate, diethyl terephthalate, diethyl isophthalate, dibutyl terephthalate, dibutyl isophthalate, and the like. Dimethyl acid and dimethyl isophthalate are preferred. These dicarboxylic acids or lower alkyl esters thereof can be used alone or in combination of two or more. These components (a) have the effect of increasing the Tg of the obtained polyester resin and improving the blocking resistance of the toner. Therefore, 90 to 99.5 mol%, preferably 93 to 99. 5 mol%, more preferably 95 to
It is contained in the range of 99.5 mol%.

The component (b), which is a straight-chain aliphatic dicarboxylic acid component having 8 or less carbon atoms, includes, for example, suberic acid, pimelic acid, adipic acid, glutaric acid, succinic acid, etc .; , Dimethyl, diethyl ester and the like, and these acid anhydrides can be used, and these can be used alone or in combination of two or more. By setting the carbon number to 8 or less, it is possible to improve the fixing performance and impact resistance of the toner, suppress the decrease in Tg and toughness of the polyester resin, and improve the blocking resistance and printing durability of the toner. it can. In the case of malonic acid or the like having 3 or less carbon atoms, decomposition may occur during esterification or transesterification, and a straight-chain aliphatic dicarboxylic acid having 4 to 6 carbon atoms is preferable. The component (b) accounts for 0.5 to 10 mol%, preferably 1 to 9 mol%, more preferably 2 to 6 mol%, based on the total acid components.
It is contained in the range of mol%. 0.5 mol% of the component (b)
By doing so, the fixing performance of the toner can be improved, and when the content is 10 mol% or less, a decrease in Tg of the polyester resin can be suppressed and the blocking resistance of the toner can be improved.

As the trihydric or tetrahydric alcohol component (c) used in the present invention, for example, trihydric alcohols such as glycerol, trimethylolpropane, trimethylolethane, 1,2,4-butanetriol, 2-methyl-1,2,3-propanetriol,
2-methyl-1,2,4-butanetriol, 1,2,2
5-pentanetriol, 1,3,5-trihydroxymethylbenzene and the like, and tetrahydric alcohols such as 1,2,3,6-hexatetralol, pentaerythritol, ditrimethylolpropane and the like, Among these, pentaerythritol and trimethylolpropane are particularly preferred. These can be used alone or in combination of two or more. These components (c) have the effect of increasing the non-offset properties of the toner by crosslinking or branching the polyester resin.

It is necessary that the content of the component (c) be in an appropriate content range depending on its valence. That is, the trivalent alcohol has a range of 3 to 15 mol%, preferably 5 to 14 mol%, and the tetrahydric alcohol has a range of 0.5 to 2.5 mol%, preferably 0.7 to 2.3 mol%. % Range. By making the trihydric alcohol 3 mol% or more or the tetrahydric alcohol 0.5 mol% or more, the polyester resin can be crosslinked or branched within an appropriate viscosity range, and the non-offset property of the toner is improved. can do. In addition, 15 alcohols
By controlling the mol% or less or the content of the tetrahydric alcohol to 2.5 mol% or less, the polyester resin is prevented from being crosslinked in an appropriate viscosity range or less, the decrease in Tg of the polyester resin is suppressed, and the toner resistance is improved. Good blocking properties can be obtained. In the polyester resin containing the trihydric or tetrahydric polyhydric alcohol component (c), since the molecular chains are not concentrated at the crosslinking points or branch points, the crosslinking points or branch points may be reduced by kneading when forming the toner. The polyester resin containing a polyhydric alcohol having a valency of 5 or more has a large number of molecular chains concentrated at the crosslink points or branch points. The physical properties of the subsequent polyester resin will change greatly.

In the present invention, examples of the aliphatic diol used as the component (d) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, neopentyl glycol, 2-ethyl-2-methylpropane-1,3-diol, 2-butyl-2-ethylpropane-1,3-diol, 1,6-hexanediol , 1,4-cyclohexanedimethanol, hydrogenated bisphenol A and the like,
These can be used alone or in combination of two or more. Among these, ethylene glycol, neopentyl glycol,
1,4-cyclohexanedimethanol is preferred. These components (d) have the effect of lowering the melt viscosity of the polyester resin, and therefore improve the fixing performance of the toner. Its content is in the range of 50 to 100 mol%, preferably 60 to 90 mol%, based on the total acid components. When the content of the component (d) is 50 mol% or more, the fixing performance of the toner can be improved. When the content is 100 mol% or less, a decrease in the Tg and moisture resistance of the resin can be suppressed, and the resistance of the toner can be improved. The blocking property and the charging performance can be improved.

In the present invention, the aromatic diol component (e) represented by the general formula (I) is a polyester resin having a Tg of
To increase the blocking resistance of the toner. For example, 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, polyoxypropylene (6.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxy Propylene (2.2)-
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-
Aromatic polyether glycols such as bis (4-hydroxyphenyl) propane and polyoxypropylene (5.0) -2,2-bis (4-hydroxyphenyl) propane may be mentioned. These may be used alone or in combination of two or more. It can be used in combination. Above all, in the aromatic diol represented by polyoxypropylene (n) -2,2-bis (4-hydroxyphenyl) propane, n is 2.1 to
4.0, and aromatic diols represented by polyoxyethylene (n) -2,2-bis (4-hydroxyphenyl) propane, wherein n is 2.0 to 2.0.
Those having a range of 3.0 are preferred.

The content of the component (e) is in the range of 10 to 60 mol%, preferably 15 to 55 mol%, based on all the acid components. By setting the content of the component (e) to 10 mol% or more, it is possible to suppress a decrease in Tg and moisture resistance of the polyester resin, and to improve the blocking resistance and the charging performance of the toner. By setting the content in the range described below, a polyester resin having a favorable softening temperature range can be obtained, and the fixing performance of the toner can be improved.

In the present invention, other monomers such as maleic acid, phthalic acid and isodecyl amber may be used in an amount of 10 mol% or less based on the total acid components, as long as the properties of the polyester resin are not impaired. Acid, dodecenyl succinic acid and the like and dicarboxylic acids such as monomethyl, monoethyl, dimethyl, diethyl ester and the like, and acid anhydrides thereof, benzoic acid, p-substituted benzoic acid, o-substituted benzoic acid, acetic acid, propionic acid, butyric acid And the following alcohols such as monocarboxylic acids such as methyl, ethyl ester and the like and acid anhydrides thereof, benzyl alcohol, p-substituted benzyl alcohol, o-substituted benzyl alcohol, lauryl alcohol, mystyl alcohol, stearyl alcohol; Polyethylene glycol, polypropylene glycol Polyalkylene glycols,
Hydroxycarboxylic acid derivatives such as ε-caprolactone, methylvalerolactone and the like and ring-opening polymers thereof can also be used.

In the production of the polyester resin for toner of the present invention, an esterification reaction or a transesterification reaction is carried out by charging a predetermined amount of the above-mentioned polymerization components into a reaction vessel and heating and raising the temperature. Or remove the alcohol out of the system. Next, the reaction is continued until the melt viscosity of the reaction mixture reaches a predetermined value. At this time, polycondensation is carried out under a pressure of 500 mmHg or less while distilling and removing a part of the aliphatic diol component out of the system. The reaction temperature is not particularly limited, and may be arbitrarily set as necessary. It is preferable that the reaction is finally performed at 180 to 260 ° C.

In the present invention, at least one metal compound selected from antimony, titanium, tin, zinc and manganese is used as the esterification catalyst or transesterification catalyst and the polycondensation catalyst in the above series of reactions. Examples of the metal compound used include titanium tetrabutoxide, dibutyltin oxide, manganese acetate, zinc acetate, and antimony trioxide.
The amount used is not particularly limited, but is preferably in the range of 10 to 2000 ppm based on all acid components.

The polyester resin of the present invention having the above constitution has a softening temperature of 120 to 160 ° C., preferably 13 to 160 ° C.
0 to 150 ° C, acid value is 0.5 to 10 mgKOH / g, preferably 0.5 to 8 mgKOH / g, more preferably 1 to 5 mgKOH / g, and Tg is 55 to 70 ° C, preferably 60 to 70 ° C. It is necessary.

This is because the toughness of the polyester resin is improved by setting the softening temperature to 120 ° C. or higher.
By setting the temperature to 160 ° C. or lower, the melt fluidity and the low-temperature fixability of the toner can be improved. Further, by setting the acid value to 0.5 mgKOH / g or more, even when a negatively charged toner is used, generation of a reversely charged toner can be suppressed. The occurrence of fog can be prevented. When the Tg is 55 ° C. or higher, the blocking resistance of the toner is good, and when the Tg is 70 ° C. or lower, the fixing performance of the toner is good.

The toner of the present invention contains the above polyester resin as a main component of the binder resin, and includes a styrene polymer, a styrene-acrylic copolymer, a styrene-butadiene copolymer, and an epoxy resin. A binder resin can be used in combination with another resin such as a system resin. Further, the toner of the present invention contains not less than 60% by weight of the binder resin as described above, and coloring agents such as carbon black, inorganic pigments, chromatic dyes and organic pigments, waxes such as polyolefin wax, Teflon, Lubricants such as zinc stearate and polyvinylidene fluoride, negatively or positively chargeable charge control agents, release agents, magnetic materials, flow modifiers such as silica, and the like can be added as necessary.

The charge control agent is used for the purpose of the charge amount and charge stability of the toner, and a charge control agent that makes the toner have a positive polarity or a negative polarity can be used. Examples of the charge control agent having a negative polarity for the toner include a metal-containing monoazo dye, a copper phthalocyanine dye, a metal complex of an alkyl derivative of salicylic acid, a quaternary ammonium salt, and a nitroimidazole derivative. The amount of the charge control agent having a negative polarity is preferably in the range of 0.1 to 3% by weight, more preferably in the range of 0.4 to 2.5% by weight, based on the total toner. Examples of the charge control agent in which the toner exhibits a positive polarity include a nigrosine dye, a phenylmethane dye containing a tertiary amine as a side chain, a quaternary ammonium salt compound, cetyltrimethylammonium bromide,
Examples thereof include polyamine resins and imidazole derivatives. The amount of the charge control agent having a positive polarity is preferably in the range of 0.1 to 5% by weight, more preferably in the range of 0.4 to 4.5% by weight, based on the whole toner. Further, two or more of the above-described positive and negative charge control agents may be used in combination.

In the toner of the present invention, a releasing agent can be used for the purpose of improving the releasability from the heat roller and improving the non-offset property. Examples of such a release agent include polyolefin, fatty acid metal salt, fatty acid ester, partially saponified fatty acid ester, higher fatty acid, higher alcohol, paraffin wax, amide wax, polyhydric alcohol ester, silicone varnish, aliphatic fluorocarbon, Silicone oil and the like. These release agents are preferably used in the toner in a range of 8% by weight or less, more preferably in a range of 6% by weight or less.

As the colorant used in the toner of the present invention,
For example, C.I. I. Solvent Yellow 21, C.I. I. Solvent Yellow 77, C.I. I. Solvent Yellow 1
14, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 1
7, C.I. I. Pigment yellow 83, C.I. I. Solvent Red 19, C.I. I. Solvent Red 49, C.I.
I. Solvent Red 128, C.I. I. Pigment Red 5, C.I. I. Pigment Red 13, C.I. I. Pigment Red 22, C.I. I. Pigment Red 48.2,
C. I. Disperse thread 11, C.I. I. Solvent Blue 25, C.I. I. Solvent Blue 94, C.I. I.
Pigment Blue 60, C.I. I. Pigment Blue 15
-Any known dyes or pigments such as chromatic dyes or pigments such as 3, carbon black, and pigments such as grafted carbon black in which the surface of carbon black is coated with a resin can be used. is not. The amount of the colorant used is preferably in the range of 0.1 to 10% by weight in the toner, and more preferably in the range of 0.5 to 8% by weight.

In the toner of the present invention, a fluidity improver or the like is used as needed. Examples of the fluidity improver include silica, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite,
Diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon oxide, silicon nitride, and the like are preferable, and silica fine powder is particularly preferable. The use amount of these fluidity improvers is preferably in the range of 0.05 to 0.7% by weight, more preferably in the range of 0.1 to 0.6% by weight in the obtained toner.

The toner of the present invention is preliminarily mixed with the above-mentioned colorant such as polyester resin and carbon black, a charge controlling agent, a release agent, etc., melted and kneaded by an extruder or the like, and cooled to obtain a crude product. It can be produced by pulverizing, finely pulverizing, classifying, and externally adding a fluid modifier such as silica. The volume average particle size of the toner is 5 to 1
The range of 5 μm is preferable, and particularly preferably 6 to 13 μm
Range. By setting the volume average particle diameter of the toner in this range, a toner having excellent image characteristics can be obtained.

[0033]

The present invention will be described below in detail with reference to examples. The physical properties and performance evaluations of the polyester resin and the toner in Examples and Comparative Examples were performed using the following methods. Softening temperature Flow tester (CFT-50, manufactured by Shimadzu Corporation)
0), using a nozzle of 1.0 mmφ × 10 mmL, a load of 294 N (30 Kgf), and measuring at a heating rate of 3 ° C./min under heating, 1/2 of 1.0 g of the sample flowed out. The temperature at this time was taken as the softening temperature (° C.).

Glass transition temperature (Tg) Differential scanning calorimeter (DSC-60) manufactured by Shimadzu Corporation
And the temperature at the intersection of the base line of the chart and the tangent to the endothermic curve near Tg when measured at a heating rate of 5 ° C./min was defined as Tg (° C.). The acid value was titrated with a potassium hydroxide solution in benzyl alcohol. Resin composition analysis The resin was hydrolyzed with hydrazine and quantified using liquid chromatography and gas chromatography.

A developer was prepared by placing 100 parts by weight of an iron carrier (EFV-200 / 300, manufactured by Powder Tech) in a polyethylene container with respect to 4 parts by weight of the fixing toner, and stirring the mixture with a roll mill for 30 minutes. Commercial copy machine (SF-78 manufactured by Sharp Corporation)
The test chart was copied by the modified machine of 50), and the test paper on which the toner was loaded was taken out without passing through the fixing section. The test paper is passed through a temperature-variable fixing roller set at a roller speed of 300 mm / sec and a nip width of 8.0 mm, and the toner is fixed only on the test paper, and the minimum temperature at which the toner does not transfer to the fixing roller is the minimum fixing. The fixing property was determined using the following criteria. A: The minimum fixing temperature is lower than 141 ° C. ：: The minimum fixing temperature is 141 to 150 ° C. Δ: Minimum fixing temperature is 151 to 160 ° C. X: The minimum fixing temperature exceeds 160 ° C.

The same operation as in the evaluation of the non-offset fixing property was performed, the temperature of the fixing roller was raised from the minimum fixing temperature, and the temperature at which toner began to adhere to the fixing roller again was defined as the hot offset start temperature. Non-offset properties were determined using the following criteria. A: Hot offset start temperature exceeds 220 ° C. ：: Hot offset start temperature is 200 to 220 ° C. X The hot offset start temperature is less than 200 ° C.

About 5 g of the anti-blocking toner was weighed and placed in a sample bottle.
Was allowed to stand for 24 hours, and the degree of aggregation of the toner was evaluated as an index of blocking resistance. The blocking resistance was determined according to the following criteria. A: Disperse by simply turning the sample bottle upside down. ：: Disperse by inverting the sample bottle and hitting it 2-3 times. X: Disperse by inverting the sample bottle and hitting it 4 to 5 times.

Printing durability A developer was prepared in the same manner as in the evaluation of the fixing property. The mixture was stirred with a roll mill for 14 days, and then, using the tester used for the evaluation of the fixing property, image drawing was performed, and the image stability was evaluated on the basis of the charge amount of the toner according to the following criteria. A: The charge amount (image density) is stable. ：: The charge amount slightly changed, but the image density was little affected. X: The image density greatly changes, and fogging and blurring occur.

The abbreviations used in Examples and Comparative Examples represent the following monomers. Diol A: polyoxypropylene- (2.3) -bis (4-hydroxyphenyl) propane Diol B: polyoxyethylene- (2.1) -bis (4-hydroxyphenyl) propane.

Example 1 3488 parts by weight of terephthalic acid, 415 parts by weight of isophthalic acid, 219 parts by weight of adipic acid, 335 parts by weight of trimethylolpropane, 1087 parts by weight of ethylene glycol, 2714 parts by weight of diol A, 1.24 parts by weight of antimony trioxide And 0.82 parts by weight of zinc acetate dihydrate were charged into a reaction vessel having a distillation column. After maintaining the internal temperature at 260 ° C. and the stirring rotation speed of 120 rpm, and performing the esterification reaction under normal pressure for 6 hours, the pressure in the reaction system was reduced to 1.0 mmHg over 30 minutes, and the internal temperature was maintained at 230 ° C. to remove ethylene glycol. The polycondensation reaction was carried out for 4 hours while distilling off to obtain a pale yellow transparent polyester resin R-1. Table 1 shows the results of the composition analysis and the resin physical properties of the obtained polyester resin R-1.

Further, 92 parts by weight of the obtained resin R-1 was used.
5 parts by weight of carbon black (# 44 manufactured by Mitsubishi Chemical Corporation), polypropylene wax (Viscole 6 manufactured by Sanyo Chemical Industries, Ltd.)
60P) and 1 part by weight of a positively chargeable charge control agent (P-51 manufactured by Orient Chemical Industries) were mixed with a Henschel mixer for 30 minutes. Next, the obtained mixture was melt-kneaded with an internal mixer (manufactured by Kurimoto Tekko). The melt-kneaded product was cooled to room temperature, roughly pulverized by a hammer mill, and then finely pulverized by a jet mill (manufactured by Nippon Pneumatic). Thereafter, classification was performed using an air classifier (manufactured by Nippon Pneumatic Co., Ltd.) to obtain a toner T-1 with a volume average particle size of 11 μm. Table 2 shows the performance evaluation results of the obtained toner T-1.

Example 2 The same operation as in Example 1 was carried out except that the charged amounts of the respective monomers were changed to the amounts shown in Table 1 and the esterification time was changed to 7 hours, to prepare a pale yellow transparent polyester resin R-2. Obtained. Table 1 shows the composition analysis result and the resin physical properties of the obtained polyester resin R-2. Using the above resin R-2, the same operation as in Example 1 was performed to obtain a toner T-2. Table 2 shows the characteristic values of the obtained toner T-2. Toner T-
Sample No. 2 had good fixing properties, non-offset properties, blocking resistance and durability.

Example 3 A light yellow transparent polyester resin R-3 was obtained in the same manner as in Example 1, except that the charged amounts of the respective monomers were changed to the amounts shown in Table 1. Table 1 shows the composition analysis result and the resin physical properties of the obtained polyester resin R-3. Using the above resin R-3, the same operation as in Example 1 was performed to obtain a toner T-3. Table 2 shows the characteristic values of the obtained toner T-3.
It was shown to. The toner T-3 has a fixing property, a non-offset property,
The blocking resistance and the image stability were good.

Example 4 The same operation as in Example 1 was carried out except that the charged amounts of the respective monomers were changed to the amounts shown in Table 1, the esterification time was changed to 7 hours, and the polycondensation time was changed to 3 hours. A transparent polyester resin R-4 was obtained. Table 1 shows the composition analysis result and the resin physical property values of the obtained polyester resin R-4. Using the above resin R-4, the same operation as in Example 1 was performed to obtain a toner T-4. Table 2 shows the characteristic values of the obtained toner T-4. Toner T-4 was excellent in fixing property, non-offset property, blocking resistance and image stability.

Example 5 The same operation as in Example 1 was carried out except that the charged amounts of the respective monomers were changed to the amounts shown in Table 1 and the esterification time was changed to 5 hours, to prepare a pale yellow transparent polyester resin R-5. Obtained. Table 1 shows the composition analysis result and the resin physical properties of the obtained polyester resin R-5. Using the above resin R-5, the same operation as in Example 1 was performed to obtain a toner T-5. Table 2 shows the characteristic values of the obtained toner T-5. Toner T-
In No. 5, the fixing property, the non-offset property, the blocking resistance and the image stability were good.

Example 6 A pale yellow transparent polyester resin R-6 was prepared in the same manner as in Example 1 except that the charged amounts of the respective monomers were set to the amounts shown in Table 1 and the esterification time was changed to 7 hours. Obtained. Table 1 shows the results of the composition analysis and the resin physical properties of the obtained polyester resin R-6. Using the above resin R-6, the same operation as in Example 1 was performed to obtain a toner T-6. Table 2 shows the characteristic values of the obtained toner T-6. Toner T-
Sample No. 6 had good fixing properties, non-offset properties, blocking resistance and image stability.

[0047]

[Table 1]

[0048]

[Table 2]

Comparative Example 1 The same operation as in Example 1 was carried out except that the charged amounts of the respective monomers were as shown in Table 3, the esterification time was 9 hours, and the polycondensation temperature was 220 ° C. A yellow transparent polyester resin R-7 was obtained. The obtained polyester resin R-
Table 3 shows the results of the composition analysis and the physical properties of the resin No. 7.
Using the above-mentioned resin R-7, the same operation as in Example 1 was performed to obtain a toner T-7. Table 4 shows the characteristic values of the obtained toner T-7. The toner T-7 is the same as the resin R-
In No. 7, the linear aliphatic dicarboxylic acid component was not present, the content of the trihydric alcohol component was large, and the acid value was high, so that the durability of the toner T-7 was poor.

Comparative Example 2 A pale yellow transparent polyester resin R-8 was prepared in the same manner as in Example 1 except that the charged amounts of the respective monomers were changed to the amounts shown in Table 3 and the esterification time was changed to 5 hours. Obtained. Table 3 shows the results of the composition analysis and the resin physical properties of the obtained polyester resin R-8. Using the above resin R-8, the same operation as in Example 1 was performed to obtain a toner T-8. Table 4 shows the characteristic values of the obtained toner T-8. Toner T-
In No. 8, the blocking resistance was poor because the amount of the aromatic dicarboxylic acid component in the resin R-8 was small, the amount of the linear aliphatic dicarboxylic acid component was too large, and the Tg was low.

Comparative Example 3 Example 1 was repeated except that the charged amounts of the respective monomers were as shown in Table 3, the esterification time was 11 hours, the polycondensation temperature was 220 ° C., and the polycondensation time was 6 hours. The same operation as described above was performed to obtain a pale yellow transparent polyester resin R-9. Table 3 shows the composition analysis result and the resin physical properties of the obtained polyester resin R-9. Using the above resin R-9,
By performing the same operation as in Example 1, a toner T-9 was obtained. Table 4 shows the characteristic values of the obtained toner T-9. Toner T
-9, the aliphatic diol component in the resin R-9 is small,
The amount of the aromatic diol component was too large, the softening temperature was low, and the non-offset properties and durability were poor.

Comparative Example 4 The same operation as in Example 1 was carried out except that the charged amounts of the respective monomers were as shown in Table 3, the esterification time was 4 hours, and the polycondensation temperature was 220 ° C. A yellow transparent polyester resin R-10 was obtained. Obtained polyester resin R
Table 3 shows the results of the composition analysis of -10 and the physical properties of the resin. Using the above resin R-10, the same operation as in Example 1 was performed to obtain a toner T-10. Obtained toner T-1
Table 4 shows characteristic values of 0. Toner T-10 is made of resin R
The fixing property and durability were poor because the aromatic diol component in -10 was not present, the softening temperature was high, and the acid value was low.

Comparative Example 5 The same operation as in Example 1 was carried out except that the charged amounts of the respective monomers were changed to the amounts shown in Table 3, the esterification time was changed to 4 hours, and the polycondensation time was changed to 3 hours. A transparent polyester resin R-11 was obtained. Obtained polyester resin R-1
Table 3 shows the composition analysis result and resin physical properties of Sample No. 1.
The same operation as in Example 1 was performed using Resin R-11 to obtain Toner T-11. Table 4 shows the characteristic values of the obtained toner T-11. Toner T-11 is resin R-1
All the evaluation items were bad because the tetrahydric alcohol component in 1 was too small and the softening temperature and Tg were low.

Comparative Example 6 A pale yellow transparent polyester resin R-12 was prepared in the same manner as in Example 1 except that the charged amounts of the respective monomers were changed to the amounts shown in Table 3 and the esterification time was changed to 11 hours. Obtained. Table 3 shows the composition analysis result and the resin physical properties of the obtained polyester resin R-12. The same operation as in Example 1 was performed using Resin R-12 to obtain Toner T-12. Table 4 shows the characteristic values of the obtained toner T-12.
Toner T-12 was low in fixability and durability because the linear aliphatic dicarboxylic acid component in resin R-12 was small and the softening temperature, Tg and acid value were high.

[0055]

[Table 3]

[0056]

[Table 4]

[0057]

The polyester resin for a toner of the present invention and the toner using the same are characterized in that a specific amount of a linear aliphatic carboxylic acid component and a trivalent or tetravalent polyhydric alcohol component is used to obtain blocking resistance, It is excellent in melt fluidity and charging performance, and is particularly useful as a binder resin and toner for high-speed copying machines and high-speed printers requiring high durability.

Claims (2)

[Claims] (A) 90 to 99.5 with respect to all acid components.
Mole% terephthalic acid component or its lower alkyl ester and / or isophthalic acid component or its lower alkyl ester;
10 mol% of a linear aliphatic dicarboxylic acid component having 8 or less carbon atoms or a lower alkyl ester or an acid anhydride thereof, (c) a trihydric or tetrahydric polyhydric alcohol component,
(D) 50 to 100 mol% of the aliphatic diol component with respect to the total acid component, and (e) 10 to 60 mol% of the aromatic diol component represented by the formula (I) with respect to the total acid component. A polyester resin, wherein the content of the polyhydric alcohol component (c) is 3 to 15% by mole based on the total acid component when the content of the polyhydric alcohol component (c) is a trihydric alcohol component, 0.5 to 2.5 mol%, a softening temperature of 120 to 160 ° C and an acid value of 0.5 to 10
mgKOH / g, glass transition temperature (Tg) 55-70
A polyester resin for a toner, which has a temperature of ℃. Embedded image (Wherein, R represents an alkylene group having 3 or less carbon atoms;
And Y are numbers that satisfy the expression 2.0 ≦ X + Y ≦ 7.0. ) 2. A toner for developing an electrostatic image, comprising the polyester resin for a toner according to claim 1 as a binder.