JP6020906B2 - Polyester resin composition for electrophotographic toner and toner for electrophotography - Google Patents

Description

The present invention relates to a polyester resin composition for an electrophotographic toner containing a polymerized rosin condensate derived from a rosin that is a plant-based natural product as a main component, and an electrophotographic toner comprising the resin composition.

  In recent years, demands for energy saving, high speed, environmental considerations, and the like have become stronger for image forming apparatuses such as printers, copiers, and facsimiles. Accordingly, the electrophotographic toner satisfies various characteristics such as low-temperature fixability, offset resistance, and blocking resistance, and the demand for using biomass is further increased.

  Development of resins for electrophotographic toner using rosins, which are plant-based natural product materials, has already been carried out. For example, in addition to attempts to improve fixability by blending rosin and rosin esters as additives into electrophotographic toner compositions, attempts have been made to introduce various rosins as constituents of polyester resins for electrophotographic toners. (For example, see Patent Documents 1 to 5).

However, the rosin-based polyester resins described in these patent documents generally exhibit low-temperature fixability when the introduction ratio of the rosin skeleton is small, and a hard and brittle property appears when the introduction ratio is relatively large. Although it was excellent in grindability, there were problems such as insufficient fixing strength (abrasion resistance) of the transferred image.

  Therefore, even when a rosin skeleton is introduced into a polyester resin at a relatively high rate from the viewpoint of environmental consideration, the hard and brittle properties are improved, and the low-temperature fixability, offset resistance, blocking resistance, and abrasion resistance are improved. Development of a new polyester resin for electrophotographic toner that can satisfy various characteristics such as the above is eagerly desired.

Japanese Patent Laid-Open No. 04-70765 JP 2007-137910 A JP 2007-292815 A JP 2008-122509 A JP 2012-181241 A

From the viewpoint of environmental considerations, the present invention provides a novel polyester resin for electrophotographic toner that uses a specific polymerized rosin derived from a rosin that is a plant-based natural product in a relatively high proportion and that satisfies the above-mentioned characteristics. It is an object of the present invention to provide, and to apply the polyester resin to an electrophotographic toner composition.

In order to solve the above-described problems of the prior art, the present inventor is particularly concerned with the types of constituent carboxylic acid components of polyester resins for electrophotographic toners, types of constituent alcohol components, and physical properties of the resulting polyester resins, as well as target products. Paying close attention to the correlation with various performances of electrophotographic toners, we made extensive studies. As a result, it has been found that a polyester resin obtained by using a specific purity of a polymerized rosin as the carboxylic acid component and a specific ether compound as the alcohol component in a specific ratio can solve the above problems. The invention has been completed.

That is, the present invention relates to a polymerized rosin having a dimer content of 60% by weight or more and / or a total carboxylic acid containing 25 to 60 mol% of the polymerized rosin lower ester, and 30 to 80 mol of etherified diphenols. %, A condensate (A) having a softening point of 90 to 150 ° C. and a glass transition point of 45 to 75 ° C. obtained as a reaction with all alcohol components contained The present invention relates to a polyester resin composition for photographic toner. The present invention also relates to an electrophotographic toner comprising the polyester resin composition for electrophotographic toner.

According to the present invention, a polyester resin composition for electrophotographic toner that is environmentally friendly and can impart excellent toner properties can be provided. The resin composition obtained in the present invention is an environmentally friendly compound that essentially uses a relatively high proportion of a specific polymerized rosin, and various properties such as low-temperature fixability, offset resistance, blocking resistance, and abrasion resistance. It is a functional compound that can satisfy the characteristics. According to the present invention, in addition to contributing to environmental protection and the like, the disadvantages in terms of physical properties of being hard and brittle compared to conventional rosin-based polyester resins for electrophotographic toners are eliminated, and the various performances are excellent. A polyester resin composition for electrophotographic toner can be provided.

The polyester resin composition for an electrophotographic toner of the present invention is characterized by containing a condensate (A) as described below as a main component, and the condensate (A) has the following requirements (1) to (5). ) Must be satisfied.

That is, the condensate (A) contains (1) a polymerized rosin and / or polymerized rosin lower ester (hereinafter referred to as polymerized rosins) containing a dimer of 60% by weight or more, preferably 80% by weight or more. (Hereinafter referred to as specific polymerized rosins) (hereinafter referred to as requirement (1)), (2) 25 to 60 mol%, preferably 30 to 50 mol% of the specific polymerized rosin in the total carboxylic acid component. It is contained (hereinafter referred to as requirement (2)), and (3) etherified diphenols are contained in 30 to 80 mol%, preferably 40 to 70 mol%, in all alcohol components (hereinafter referred to as , Requirement (3)), (4) the softening point of the condensate (A) is 90 to 150 ° C., preferably 100 to 140 ° C. (hereinafter referred to as requirement (4)), (5) condensate ( A) Glass transition point 45 to 75 ° C., more preferably at 50-65 ° C., are those comprising all the requirements made of (hereinafter referred to as requirements (5)). In the polymerized rosin lower ester, “lower” means a methyl, ethyl, or propyl group. Hereinafter, the expression “lower” described separately also has the same meaning.

As the specific polymerized rosin used in the present invention, it is more preferable to use a polymerized rosin starting from distilled rosin or the hydride when the color tone is important in the intended use. It does not specifically limit as a manufacturing method of the said polymerized rosins, A well-known various method is employable. The use ratio of the specific polymerized rosins is in the range shown in the requirement (2). If the use ratio is less than 25 mol%, the softening point of the resulting condensate (A) is likely to be lowered. There is a tendency that the anti-blocking property or offset resistance of the toner for electrophotography does not reach a desired level. On the other hand, when the use ratio exceeds 60 mol%, the softening point of the resulting condensate (A) tends to be high, and the low-temperature fixability of the electrophotographic toner using the same tends to decrease.

Examples of the divalent carboxylic acids used for obtaining the condensate (A) include the following compounds in addition to the specific polymerized rosins which are characteristic portions in the present invention. Examples of the compound include aliphatic dibasic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid; maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic Unsaturated dibasic acids such as acids; aromatic dibasic acids such as phthalic acid, isophthalic acid and terephthalic acid; alkyl groups or alkenyls having 1 to 20 carbon atoms such as dodecenyl succinic acid, dodecyl succinic acid, octenyl succinic acid, octyl succinic acid, etc. Succinic acid substituted with a group; (meth) acrylic acid addition rosin and the like, and anhydrides and lower esters which are derivatives thereof. Any of these may be used alone or in appropriate combination.

The amount of the other divalent carboxylic acids used is reasonably determined in consideration of the amount of the specific polymerized rosin used, and is usually about 40 to 75 mol% of the total carboxylic acid component (100 mol%). Preferably it is 50-70 mol%. If the use ratio is less than 40 mol%, the amount of the specific polymerized rosin used may exceed the upper limit of the requirement (2), and the softening point of the resulting condensate (A) tends to be high. There is a tendency that the low-temperature fixability of the resin for an electrophotographic toner obtained by using the toner decreases. In addition, if the use ratio exceeds 75 mol%, the amount of the specific polymerized rosin used may be lower than the lower limit of the requirement (2), so that the softening point of the resulting condensate (A) tends to be low. There is a tendency that the anti-blocking property or anti-offset property of the resin for electrophotographic toner obtained by using the toner does not reach a desired level. In addition, when (meth) acrylic acid addition rosin is used, the usage-amount is 20 mol% or less among all the carboxylic acid components, Preferably it is 15 mol%. When the use ratio exceeds 20 mol%, the resulting condensate (A) is hard and easily brittle.

As the carboxylic acid component used to obtain the condensate (A), in addition to the above divalent carboxylic acids, a monovalent carboxylic acid or a trivalent or higher carboxylic acid (the carboxylic acid anhydride, the lower Including esters). These compounds can be used within the range in which the resin for electrophotographic toner using the obtained condensate (A) can express desired performances in the present invention. By using these compounds, the condensate obtained ( The degree of crosslinking in A) can be adjusted as appropriate.

Examples of the monovalent carboxylic acid include fatty acids, monofunctional rosins, and t-butylbenzoic acid. The amount of monovalent carboxylic acid used is usually 10 mol% or less, preferably 5 mol% or less of the total carboxylic acid component. If the use ratio exceeds 10 mol%, the degree of cross-linking of the resulting condensate (A) tends to be low, so that the electrophotographic toner resin obtained using this has a desired level of blocking resistance or offset resistance. There is a tendency not to reach.

Examples of the trivalent or higher carboxylic acids include 1,2,4-butanetricarboxylic acid, trimellitic acid, naphthalenetricarboxylic acid, pyromellitic acid, maleated rosin, fumarated rosin, and acid anhydrides thereof. And lower esters. Among these, trimellitic acid or the anhydride can be preferably used because it is inexpensive and easy to control the reaction.

The amount of trivalent or higher carboxylic acids used is usually 10 mol% or less, preferably 5 mol% or less of the total carboxylic acid component. If the use ratio exceeds 10 mol%, the degree of crosslinking of the resulting condensate (A) tends to be high, and the low-temperature fixability of the resin for electrophotographic toners obtained using this tends to not reach a desired level. There is.

As the alcohol component used for obtaining the condensate (A), etherified diphenols which are characteristic parts in the present invention are essential. Examples of the etherified diphenols include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4- Hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, poly Oxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, etc. And an alkylene oxide adduct of bisphenol A. The average number of moles of alkylene oxide added is about 1 to 16, preferably 2 to 8.

The amount of etherified diphenols used is in the range shown in the above requirement (3), and if the use ratio is less than 30 mol%, the softening point of the resulting condensate (A) is likely to be lowered. The anti-blocking property or the anti-offset property of the electrophotographic toner using this tends to not reach a desired level. On the other hand, when the use ratio exceeds 80 mol%, the softening point of the resulting condensate (A) tends to be high, so that the low-temperature fixability of the electrophotographic toner using the same tends to decrease.

Other dihydric alcohols used to obtain the condensate (A) include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neo Pentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, Examples thereof include hydrogenated bisphenol A, and these compounds are used alone or in appropriate combination.

The amount of the other dihydric alcohol used is reasonably determined in consideration of the amount of the etherified diphenol used, and is usually about 20 to 70 mol% of the total alcohol acid component (100 mol%). Preferably it is 30-60 mol%. If the use ratio is less than 20 mol%, the use amount of etherified diphenols may exceed the upper limit of requirement (3), and the softening point of the resulting condensate (A) tends to be high. There is a tendency that the low-temperature fixability of the resin for an electrophotographic toner obtained by using this is lowered. Moreover, since the usage-amount of etherified diphenols may fall below the lower limit of a requirement (3) when this usage rate exceeds 70 mol%, the softening point of the condensate (A) obtained tends to become low. There is a tendency that the blocking resistance or offset resistance of the resin for electrophotographic toner obtained by using this does not reach a desired level.

Moreover, trihydric or more alcohols can also be used for an alcohol component. Examples of the trivalent or higher alcohols include glycerin, trimethylolpropane, 2-methylpropanetriol, pentaerythritol, dipentaerythritol, sorbitol, etc., and these compounds may be used alone or in appropriate combination. Used.

The amount of the trihydric or higher alcohol used is not particularly limited, but is usually 10 mol% or less, preferably 5 mol% or less of the total alcohol acid component. When the use ratio exceeds 10 mol%, the degree of crosslinking of the resulting condensate (A) becomes too high, and the low-temperature fixability of the resin for electrophotographic toner obtained using this tends to not reach a desired level. is there.

The manufacturing method of a condensate (A) is not specifically limited, Well-known various esterification reaction and transesterification can be selected suitably. For example, if all the carboxylic acid components and all alcohol components are charged into a predetermined reaction vessel, and dehydration condensation proceeds at about 180 to 260 ° C. while blowing an inert gas in the presence or absence of an esterification catalyst. Good. The charging ratio of the total carboxylic acid component and the total alcohol component is not particularly limited, but usually the OH / COOH (equivalent ratio) is about 1.2 to 0.8, preferably 0.9 to 1.1. What is necessary is just to determine each preparation amount. The reaction can be traced by measuring the acid value, viscosity or softening point. Examples of the esterification catalyst include zinc acetate, zinc oxide, stannous oxide, monobutyltin oxide, dibutyltin oxide, dibutyltin dilaurate, tetraalkylorthotitanate, and zirconium alkoxide. As the tetraalkyl orthotitanate, tetraethyl orthotitanate and tetrabutyl orthotitanate are preferably used. As the zirconium alkoxide, tetraethyl orthozirconate, tetraisopropyl orthozirconate and the like are preferably used.

The softening point of the condensate (A) is determined as described in the above requirement (4) in consideration of various properties such as low-temperature fixability, offset resistance, and blocking resistance.

The glass transition point of the condensate (A) is determined as in the requirement (5) in consideration of the above characteristics.

The polyester resin composition for an electrophotographic toner of the present invention contains the condensate (A) as a main component. The resin composition of the present invention may contain various additives in advance as required, but a method of adding these additives when preparing a toner is more general. Examples of the additive include a coloring agent, a charge control agent, a fluidity improver, a cleaning improver, a conductive filler, an extender, a reinforcing filler such as a fibrous substance, an antioxidant, an antiaging agent, and an offset preventing agent. These may be used alone or in combination of two or more.

  By using the polyester resin composition for electrophotographic toner of the present invention as a binder resin for toner, it is possible to provide an electrophotographic toner excellent in various properties such as low-temperature fixability, offset resistance, blocking resistance and abrasion resistance. . In the polyester resin composition for electrophotographic toner and the toner for electrophotography of the present invention, a known binder resin, for example, a vinyl resin such as styrene-acrylic resin, an epoxy resin, and the like, as long as the effects of the present invention are not impaired. Although other resins such as polycarbonate and polyurethane may be added, the content of the polyester resin for electrophotographic toner of the present invention (condensate (A)) is usually 70% by weight or more in the total binder resin, Preferably it is 80 weight% or more, and it is still more preferable that it is 100 weight% substantially.

  As the colorant, known various dyes and pigments used as toner colorants can be used without particular limitation. For example, carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B , Rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, disazo yellow and the like. The toner of the present invention may be either black toner or color toner. The content of the colorant is usually 1 to 40 parts by weight, preferably 2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  As the charge control agent, various substances from low molecular weight compounds to high molecular weight compounds can be used. For example, a high molecular weight compound obtained by homopolymerizing or copolymerizing a nigrosine dye, a quaternary ammonium salt compound, and a monomer having an amino group. And organometallic complexes and chelate compounds.

  The flow modifier is added to improve the fluidity of the toner, and examples thereof include vinylidene fluoride fine powder, polytetrafluoroethylene fine powder, and wet or dry silica fine powder.

  The method for producing the electrophotographic toner of the present invention is not particularly limited. For example, a pulverized toner can be prepared by a melt-kneading method. When the pulverized toner is produced, the polyester resin composition for electrophotographic toner of the present invention and the additives are premixed with a mixer such as a Henschel mixer and then melted using a known kneader such as a closed kneader. A kneaded material is prepared. Next, the kneaded product is cooled and coarsely pulverized, and then toner particles having a desired predetermined particle diameter are prepared by a mechanical pulverization method or an air pulverization method. Further, if necessary, the toner particles are usually classified by an air classifier or the like so that the volume average particle diameter is adjusted to 5 to 15 μm.

  The electrophotographic toner composition of the present invention can be used as a one-component developing toner or as a two-component developer mixed with a carrier.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. Parts and% are based on weight unless otherwise specified.

Measurements performed in each example and comparative example are as follows.
Acid value: Conforms to the method of JIS K0070.
Softening point: A flow tester (manufactured by Shimadzu Corporation, trade name “CFT-500D”) was used, and the temperature at the time of 4 mm penetration was defined as the softening point.
Glass transition point: Measured using a differential scanning calorimeter (trade name “DSC220C”) manufactured by Seiko Electronics Co., Ltd., and the obtained shoulder value was defined as a glass transition point.

Production Example 1 (Synthesis of condensate (A) by esterification reaction)
In a reactor equipped with a cooling pipe, thermometer, water separator, stirrer and nitrogen introduction pipe, 162 parts of polymerized rosin (dimer content: 80%), 100 parts of isophthalic acid, 14.6 parts of adipic acid, poly 338 parts of oxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 29.5 parts of neopentyl glycol, 2.9 parts of glycerin and 0.5 parts of n-butyltin oxide as an esterification catalyst Then, the temperature is gradually raised while stirring under a nitrogen stream, and the reaction product water is removed from the system with a water separator and kept at 180 to 250 ° C. for about 10 hours for esterification reaction, A condensate (A) was obtained (hereinafter referred to as condensate (A1)). The condensate (A1) had an acid value of 15 mgKOH / g, a softening point of 130 ° C, and a glass transition point of 63 ° C.

Production Example 2 (Synthesis of condensate (A) by transesterification reaction)
In a reaction apparatus equipped with a cooling pipe, a thermometer, a stirrer, a nitrogen introducing pipe and a distillation column, 270 parts of polymerized rosin (dimer content: 80%), 38.8 parts of dimethyl terephthalate, 43.8 parts of adipic acid , 241.5 parts of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 30.6 parts of ethylene glycol, 4.2 parts of trimethylolpropane, and 0.5 mg of zinc acetate as a transesterification catalyst. After 5 parts were charged, the ester exchange reaction was carried out at 170-230 ° C. while removing the generated methanol outside the system while stirring under a nitrogen stream. Subsequently, the condensate (A) was obtained by carrying out esterification reaction at 180-250 degreeC for about 10 hours (henceforth a condensate (A2)). The condensate (A2) had an acid value of 12 mgKOH / g, a softening point of 125 ° C, and a glass transition point of 60 ° C.

Production Examples 3 and 4 (synthesis of condensate (A))
In Production Example 1 or 2, an esterification reaction or a transesterification reaction was carried out in the same manner except that the kind and amount of raw materials used were changed as shown in Table 1 to obtain various condensates (A) ( Hereinafter, the condensates (A3) and (A4) are referred to in order). Table 3 shows the acid value, softening point and glass transition point of these condensates.

Comparative production examples 1 to 5 (synthesis of condensates for comparison)
In Production Example 1 or 2, an esterification reaction or a transesterification reaction was performed in the same manner as described in Table 2 except that the type and amount of the raw materials used were changed, and various comparative condensates were obtained (hereinafter referred to as “the following”). , In order, condensates (C1) to (C5)). Table 3 shows the acid value, softening point and glass transition point of these condensates.

In Tables 1 and 2, the specific polymer rosin 1 is a polymer rosin having a dimer content of 80%, the specific polymer rosin 2 is a polymer rosin having a dimer content of 60%, and the comparative polymer rosin is a dimer. 40% polymerized rosin, IPhA is isophthalic acid, AdPA is adipic acid, DMT is dimethyl terephthalate, TPhA is terephthalic acid, SBA is sebacic acid, TMAn is trimellitic anhydride, BPE Is polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, BEE is polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, and EG is Ethylene glycol, NPG is neopentyl glycol, 1,2-PG is 1,2-propanediol, 1,3-PG is 1,3-propanediol, GLY is group Serine, TMP is trimethylol propane, means respectively.

Examples 1-4 and Comparative Examples 1-5
(Preparation of polyester resin for electrophotographic toner and toner for electrophotography)
For 92 parts of each condensate obtained in Production Examples 1 to 4 and Comparative Production Examples 1 to 5, 4 parts of carbon black (manufactured by Mitsubishi Chemical Corporation, “MA-11”) and polypropylene wax (Sanyo Kasei) 4 parts of Kogyo Co., Ltd., “Viscol 550P”) were mixed with a super mixer and then kneaded with a twin screw extruder. The obtained kneaded product is cooled and coarsely pulverized, then finely pulverized with a jet mill (manufactured by Nippon Pneumatic Industry Co., Ltd.), and then classified with a powder airflow classifier to obtain an average particle size of 10 to 13 μm. No toner was obtained. A developer was prepared by mixing 5 parts of the toner and 95 parts of a ferrite carrier (the obtained developers were sequentially referred to as T1 to T4 and CT1 to CT3).

Each developer was developed using an electrophotographic copying machine, and then the image was transferred onto plain paper to obtain unfixed paper. Subsequently, the low-temperature fixability, offset resistance, offset resistance and wear resistance were evaluated according to the following evaluation methods.

(Low temperature fixability)
Solid printing was performed by changing the surface temperature of a fixing roller (rotation speed: 300 mm / sec) formed of Teflon (registered trademark) on the surface from 100 ° C. to 250 ° C. Using a dyeing wear tester, the fixed image was rubbed with a PPC pad under a load of 300 g, and the image density before and after the friction was measured using a reflection densitometer manufactured by Macbeth. The surface temperature of the fixing roller when the density after friction reaches 70% with respect to the density before friction is defined as the minimum fixing temperature, and the lower the temperature, the better the low-temperature fixing property. The results are shown in Table 4.

[Offset resistance]
In the same manner as the measurement of the low temperature fixability, the fixing process was performed, and the surface temperature of the fixing roller when the white background portion of the paper began to become dirty was defined as the hot offset occurrence temperature. It shows that offset resistance is so favorable that this temperature is high. The results are shown in Table 4.

[Blocking resistance]
The developer was allowed to stand for 48 hours in an incubator at a temperature of 50 ° C. and a relative humidity of 50%, allowed to cool at room temperature, and then visually observed for the degree of occurrence of aggregation, and evaluated according to the following evaluation criteria. The results are shown in Table 4.

〔Evaluation criteria〕
○: Aggregation is not recognized at all.
Δ: Slight aggregation is observed.
X: Aggregation is clearly observed.

(Abrasion resistance)
Solid printing was performed with the fixing roller having a surface temperature of 150 ° C. Using a dyeing wear tester, the fixed image was rubbed with a PPC pad under a load of 300 g, and the image density before and after the friction was measured using a reflection densitometer manufactured by Macbeth. The abrasion resistance was evaluated by the ratio of the concentration after friction to the concentration before friction. The surface temperature of the fixing roller is set to the minimum fixing temperature, and the lower the temperature is, the better the low temperature fixing property is. The results are shown in Table 4.

〔Evaluation criteria〕
○: The ratio is more than 95%.
Δ: The ratio is 90% or more and 95% or less.
X: The ratio is less than 90%.

From Table 4, the electrophotographic toner using the electrophotographic polyester resin composition of the present invention is superior to the comparative electrophotographic toner, and has low-temperature fixability, offset resistance, blocking resistance, It is clear that various properties such as wear resistance can be satisfied at the same time.

Claims (6)

All carboxylic acids containing 25-60 mol% of polymerized rosin and / or the polymerized rosin lower ester having a dimer content of 60% by weight or more, and all alcohols containing 30-80 mol% of etherified diphenols A polyester resin for an electrophotographic toner, comprising as a main component a condensate (A) having a softening point of 90 to 150 ° C. and a glass transition point of 45 to 75 ° C., obtained by reacting with components. Composition. 2. The polyester resin composition for electrophotographic toner according to claim 1, wherein a dimer content of the polymerized rosin and / or polymerized rosin lower ester is 80% by weight or more. The polyester resin composition for electrophotographic toner according to claim 1 or 2, wherein the etherified diphenol is an alkylene oxide adduct of bisphenol A. The polyester resin composition for electrophotographic toner according to any one of claims 1 to 3, wherein the polymerized rosin and / or the polymerized rosin lower ester is contained in an amount of 30 to 50 mol% in all carboxylic acid components. The polyester resin composition for electrophotographic toner according to any one of claims 1 to 4, wherein the etherified diphenol is contained in an amount of 40 to 70 mol% in all alcoholic acid components. An electrophotographic toner comprising the polyester resin composition for an electrophotographic toner according to claim 1.