JPS61124959A - Electrophotographic developer - Google Patents

Abstract

PURPOSE:To obtain a developer prevented from offset and fixable at lower temp. by using a binder resin composed essentially of a polymer prepared by using an alcohol having >=2 OH groups and a tertiary amino group and/or an epoxy group having a tertiary amino group as reactants. CONSTITUTION:The essential component of the binder resin is prepared by allowing (c) the alcohol having >=2 OH groups and a tertiary amino group and/or an epoxy group having a tertiary amino group to react in polymerizing (a) styrene and/or its deriv. and (b) one selected from methacrylic acid, acrylic acid, and their ester. The component of (c) of the alcohol is represented by formula [I]-[IV] and it is used in an amt. of 0.05-50wt% of the total weight of the monomers and not above the amt. of (c) by molar basis.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a developer composition for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The present invention relates to a developer composition.

[Conventional technology and problems]

As a conventional electrophotographic method, as described in U.S. Patent Nos. 2,297,691 and 2,357,809, etc.
A photoconductive insulating layer is uniformly charged, the layer is then exposed to light, and the charge on the exposed portions is dissipated to form an electrical latent image, which is then coated with a colored pigment called toner. After the visible image is transferred to a transfer material such as transfer paper (transfer process), it is heated,
It consists of a step of permanently fixing (fixing step) by pressure or other suitable fixing method.

In this way, toner is used not only in the development process but also in the transfer process.
It must have the functions required in each step of the fixing process.

Generally, toner is subjected to mechanical frictional force due to shearing force and impact force during mechanical operation in a developing device, and deteriorates while copying several thousand to tens of thousands of sheets. To prevent such toner deterioration, it is best to use a strong resin with a large molecular weight that can withstand mechanical friction, but these resins generally have a high softening point and are suitable for non-contact fixing methods such as oven fixing and infrared fixing. With radiant fixing, the thermal efficiency is poor, so fixing is not sufficient.Also, since the contact fixing method has good thermal efficiency, even in the widely used heat roller constant fixing method, it is necessary to use the heat roller to achieve sufficient fixing. It becomes necessary to raise the temperature, which not only causes adverse effects such as deterioration of the fixing device, curling of paper, and increased energy consumption, but also causes a significant drop in production efficiency when producing toner by pulverizing such resins. descend. Therefore, it is not possible to use a binder resin whose polymerization degree and even softening point are too high.

On the other hand, in the heat roller fixed fixing method, the heating roller surface and the toner image surface of the fixing sheet come into pressure contact, so the thermal efficiency is extremely high, and it is widely used from low speeds to high speeds.
When the heating roller surface and the toner image surface come into contact, a so-called offset phenomenon tends to occur, in which the toner adheres to the heating roller surface and is transferred to a subsequent transfer paper or the like. To prevent this phenomenon, the surface of the heating roller is treated with a material with excellent mold release properties such as fluorine-based resin, and in addition, a mold release agent such as silicone oil is applied to the surface of the heating roller to completely prevent the offset phenomenon. are doing.

However, the method of applying silicone oil etc.
This is not preferable because the fixing device becomes large, which not only increases cost but also makes it complicated, which tends to cause trouble.

In addition, as described in Japanese Patent Publication No. 55-6895 and Japanese Patent Application Laid-open No. 56-98202, there is a method to improve the offset phenomenon by widening the molecular weight distribution width of the binder resin, but the degree of polymerization of the resin increases and the fixation The temperature also needs to be high.

As a further improved method, as described in Japanese Patent Publication No. 57-493, Japanese Patent Application Laid-open No. 50-44836, and Japanese Patent Application Publication No. 57-37353, there is a method of improving the offset phenomenon by making the resin asymmetrical and crosslinking it. However, the retention point has not improved.

-a, since the minimum fusing temperature is between cold offset and hot offset, the usable temperature range is between the minimum fusing temperature and hot offset. By raising the hot offset temperature as much as possible, the fixing temperature used can be lowered and the usable temperature range can be expanded, resulting in energy savings, faster fixing, and prevention of paper curl. In addition, since double-sided copying can be performed without trouble, there are many advantages such as making the copying machine more intelligent, controlling the temperature of the fixing device more accurately, and relaxing the tolerance range.

Therefore, resins and toners with good fixing properties and offset resistance are always desired.

In addition, when using a styrene-based binder resin to achieve such requirements, Japanese Patent Application Laid-Open Nos. 49-65232 and 1972
As described in No. 0-28840 and JP-A-50-81342, methods of adding paraffin wax, low molecular weight polyolefin, etc. as anti-offset agents are known; It has also been confirmed that in the case of polyester resin, even if the above-mentioned offset preventing agent is applied, it has little effect, and that the more the amount used, the faster the developer deteriorates.

Polyester resin inherently has good fixing properties, and can be sufficiently fixed even in a non-contact fixing method, as described in U.S. Pat. It was difficult to use.

As described in JP-A-50-44836, JP-A-57-37353, and JP-A-57-409,875, polyester resins with improved offset resistance using polyhydric carboxylic acids have sufficient properties for use. Those that do not have anti-offset properties, or those that do, not only sacrifice the low-temperature fixing properties inherent to polyester resins, but also
Even in the toner production process, the crushability was extremely poor, and there were also problems in developer production.

Generally, a toner is composed of a binder resin, a colorant, and other additives, with the binder resin being the main component. As toner binder resin, coumarone indene resin,
Terpene resin, styrene resin or their copolymer resin,
Polyester resins, epoxy resins, etc. are generally used, but there are few binder resins that are strongly triboelectrically charged to positive polarity.To make the toner positive polarity, it is recommended to add additives such as nigrosine dye as a charge control agent. It is generally known that toner particles have poor compatibility with the binder resin that constitutes the main component of the toner, and if toner particles are mixed for a long time in the developing device, the particles will break and nigrosine etc. will simply be dispersed. If this is the case, particles of opposite (negative) polarity that do not contain nigrosine or the like are generated, and a so-called smearing phenomenon occurs in which toner adheres to areas where there is no image signal. Furthermore, when nigrosine dye or the like is used, since it has hydrophilic properties, the amount of charge changes depending on the humidity of the environment, resulting in a decrease in image quality. In addition, nigrosine dyes generally have strong coloring and have disadvantages such as being incompatible with color toners. In view of the above, it is desired to develop toner binder resins and toners that are strongly positively charged, unaffected by environmental humidity, and have excellent durability.

The present invention was made to meet these demands, and its purpose is to prevent offset prevention liquid from being applied in a heat roller constant fixing method (a developing method that prevents offset and allows fixing at a lower fixing temperature). The goal is to provide medicine.

Another object of the present invention is to provide a developer which can prevent offset without adding an offset preventive agent in a heat roller constant fixing method and which can be fixed at a lower fixing temperature.

Another object of the present invention is to provide a developer that has good fluidity, does not cause profking, and has a long life (hard to deteriorate).

Another object of the present invention is to provide a developer that exhibits good crosstalk and pulverizability during developer production.

Another object of the present invention is to provide a dry developer for electrophotography,
The object of the present invention is to provide a toner that forms clear and fog-free images by using a toner binder resin that inherently has a strong (electrostatic) property, and more specifically, to improve the effects of environmental humidity on the above-mentioned drawbacks. It is an object of the present invention to provide a toner in which the binder resin essentially has positive triboelectric charging properties, which is extremely small and has excellent durability.

Another object of the present invention is to provide a clear color developer with good transparency.

[Means for solving problems]

The present inventors have arrived at the present invention as a result of intensive research to achieve the above object.

That is, the present invention provides an electrophotographic developer containing a binder resin and a colorant as main components, in which the main components of the binder resin are (a) styrene and/or a styrene derivative, and (b) methacrylic acid, acrylic acid. When producing a polymer from an acid and one or more monomers selected from these esters, ()1
) Dihydric or higher alcohol having a tertiary amino group and/
Alternatively, the present invention relates to an electrophotographic developer characterized by being a resin reacted with an epoxy compound having a tertiary amino group.

In a preferable electrophotographic developer composition of the present invention, the compound (c) used in the production of the binder resin has the following components:
A dihydric or higher alcohol having a tertiary amino group represented by the following general formulas ('I) to [■], the amount of which is 0.05 to 50% by weight based on the total amount of monomers, and its use The number of moles does not exceed the number of moles of the component (b).

-=T1* -Rh old) -Rs-N-Rq-OB ・・・・・・
・(II) R8 (in formula (I) to (I!/), RI+ Rtr R5I
R61R? IR□Rq+ R1O+ RII+ R1!
+ RI31 RI#+ RI6 has 1 to 15 carbon atoms
is an alkylene group, Rat R4 is an alkyl group having 1 to 10 carbon atoms, RI? + RIM represents an alkyl group having 1 to 4 carbon atoms, and R17 and R11+ may form a heterocyclic ring of the same nitrogen atom. RI5 is shown, and X represents a hydrogen atom or a hydroxyl group. ) More preferably, the resin has a softening temperature of 100 to 160 using a Koka type flow tester.
℃, and the glass transition temperature is 50°C or higher.

Examples of the styrene or styrene derivative (a) in the present invention include styrene, 0-methylstyrene, m
-Methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-7'thylstyrene, p-tart-butylstyrene, p-n-hexylstyrene, p -n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene,
3,4-dichlorostyrene and others may be mentioned.

Examples of (b) methacrylic acid, acrylic acid, or esters thereof include acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and tert-acrylate. Butyl, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate,
lauryl acrylate, 2-ethylhexyl acrylate,
Stearyl acrylate, methoxyethyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methacrylic acid, methyl methacrylate, methacrylate Ethyl acid, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, methacrylic acid Decyl, lauryl methacrylate, methacrylic acid 2
-Ethylhexyl, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and others.

Further, as the dihydric or higher alcohol having a tertiary amino group represented by the general formulas (I) to (IV) (c) in the present invention, the following may be mentioned.

(1) Alcohol represented by general formula CI) N,N"-bis(hydroxymethyl)piperazine, N,N'-bis(
hydroxymethyl)methylpiperazine, N,N'-bis(2-hydroxyethyl)piperazine, N,N'-bis(2-hydroxypropyl)piperazine, N,N'-bis(2-hydroxypropyl")-2, 5-dimethylpiperazine, N,N'-bis(2-hydroxyethyl)-
2,5-dimethylpiperazine, N, N'-bis(2-
Hydroxy-2-methylpropyl)piperazine, N,
N'-bis(2-methyl-2-hydroxynonyl)piperazine, N,N'-bis, (2-hydroxy-3-
methoxylpropyl)piperazine, N,N'-bis(
3-phenyl-2-hydroxypropyl)piperazine, etc.

(2) Alcohol represented by the general formula (nl) N, N-bis(2-hydroxyethyl)methylamine, N, N-bis(2-hydroxyethyl)cyclohexylamine, N
, N-bis(2-hydroxypropyl)methylamine,
N,N-bis(2-hydroxypropyl)isopropylamine, triethanolamine, etc.

(3) Alcohol N represented by general formula (III), N
'-dimethyl-N, N'-bis(2-hydroxyethyl)ethylenediamine, N,N'-dicyclohexyl-
N,N'-bis(2-hydroxyethyl)hexamethylenediamine, N,N'-diethyl-N,N'-bis(
2-hydroxypropyl)ethylenediamine, N, N'
-dibutyl-N.

N''-bis(2-hydroxypropyl)pentamethylenediamine, etc.

(4) Alcohol represented by general formula (IV) 2-methyl-2-N, N-dimethylaminomethyl-1,3-propanediol, 2-methyl-2-N, N-diethylaminomethyl-1,3- Propanediol, 2-ethyl-2-
N,N-di-n-propylaminomethyl-1,3-propanediol, 2-methyl-2-N,N-di-n-butylaminomethyl-1,3-propanediol, 2-methyl-2- N,N-dimethylaminoethyl-1,3-propanediol, 2-methy/1z-2-piperidinomethyl-1,3-propanediol, bis(2-N,N-dimethylaminomethyl)-1,3-propane Diol, bis(2-N,N-di-isopropylaminomethyl) = 1,
3-propanediol, 3-methyl-3-N, N-dimethylaminomethyl-1,5-bentanediol, 3-methyl-3-N, N-diethylaminomethyl-1,5-bentanediol, 4-ethyl- 4-N,N-diisopropylaminomethyl-1,6-hexanediol and the like.

Examples of the epoxy compound having a tertiary amino group include the following.

Among the components constituting the binder resin according to the present invention, (a) styrene or styrene derivative forms the main skeleton of the resin,
(b) (Meth)acrylic acid or its ester adjusts the thermal properties such as the softening point of the resin, and the component (c) determines the charge and band.

It is a component that adjusts the amount of electricity, lowers the fixing temperature, and improves offset resistance, but if the content of component (c) is less than 0.05% by weight based on the total amount of monomers, it will not have any effect, and will not be effective at 50% by weight.
If it exceeds this, the moisture resistance of the toner will deteriorate.

Further, the softening point of the resin used in the developer composition of the present invention is preferably 100 to 160°C using a Koka type flow tester; if it is too low, the offset resistance will be insufficient, and if it is too high, the fixing property will be insufficient. Become.

The method for producing the binder resin of the present invention is carried out by a well-known addition polymerization reaction.

Colorants used in the present invention include carbon black, acetylene black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base,
Examples include Solvent Red 49, Tulben Trend 146, Solvent Blue 35, and mixtures thereof, and are usually used in an amount of about 1 to 15 parts by weight per 100 parts by weight of the binder resin.

When making a magnetic toner using the binder resin according to the present invention,
Examples of magnetic materials include alloys or compounds containing elements exhibiting ferromagnetism, such as ferrite and magnetite.
The magnetic material can be used in the form of a fine powder with an average particle size of 0.1 to 1 μm and dispersed in a binder resin in an amount of 40 to 70% by weight.

Known property improving agents contained in toner include charge control agents, anti-offset agents, fluidizing agents, etc., but since the resin of the present invention has good properties by itself, these agents may not be used during toner preparation. It becomes unnecessary to add a property improver, or even if it is added, only a small amount is required.

〔Example〕

Examples of the invention will be described below, but the invention is not limited to these examples. It should be noted that all composition ratios shown in Examples are expressed in parts by weight.

Example 1 500 parts of xylene, N,
N'-bis(2-hydroxypropyl)piperazine 50
1 part and 2 parts of dibutyltin oxide, and the temperature was adjusted to 80°C. A mixed solution of 820 parts of styrene, 130 parts of n-butyl acrylate, and 10 parts of α,αゝ-azobisisobutyronitrile was dropwise polymerized over 4 hours under a nitrogen stream. After aging at the same temperature for 10 hours after completion of the dropwise addition, the temperature was gradually raised to 210°C while reducing the pressure to 2 mmHg, xylene was distilled off, the molten resin was taken out into a stainless steel vat, allowed to cool, and pulverized. Powdered resin (Koka type flow tester softening point 126.0℃, Tg 62.0℃
) was obtained. This softening point was determined by heating a 1 cm3 sample at a heating rate of 6°C/min using a Koka-type flow tester (manufactured by Shimadzu Corporation) and applying a pressure of 20 kg/co+" using a plunger.
By applying a load of The corresponding temperature is taken as the softening point.

After mixing 93 parts of the resin and 7 parts of carbon black (SU-GAL 400R, manufactured by CABOFT) in a ball mill, coarsely pulverize with a hammer mill, finely pulverize with a jet mill, and classify, a toner having an average particle size of 13.5 μm was obtained. Obtained. The obtained toner was mixed with carrier iron powder (iBFV-20 manufactured by Nippon Tetsuko Co., Ltd.).
0/300) and measured the charge amount with a blow-off measuring device, it was +19 μc/g. 91 g of the toner was mixed with 1209 g of carrier iron powder to prepare a developer, and a commercially available electrophotographic copying machine ( The photoreceptor is an organic photoconductor, the fixing roller has a diameter of 60 mm, and a rotation speed of 2
55 m+m/sec, the temperature of the heat roller in the fixing device was made variable and the oil coating device was removed), and the image was produced clearly without background smudges, smudges, or black solid areas. Obtained.

When the fixing temperature was controlled at 140° C. to 220° C. and the image fixability and offset property were evaluated, the image was sufficiently fixed at 150° C. and no hot offset occurred. 5
When images were printed up to 10,000 sheets, clear images were obtained without any visible blurring or missing solid black areas.

The minimum fixing temperature here is 15++ua x 7 for the bottom surface.
．． Place a 500g load on a 5m+s sand eraser, rub it back and forth 5 times over the fixed image through the fixing device, measure the optical reflection density with a Macbeth reflection densitometer before and after rubbing, and determine the fixing rate as defined below. This refers to the temperature of the fixing roller when the temperature exceeds 70%.

Example 2 500 parts of xylene and 20 parts of triethanolamine are charged into the reactor of Example 1, and the temperature is adjusted to 80°C. Under a nitrogen stream, 790 parts of α-methylstyrene, 10 parts of acrylic acid, 180 parts of 2-ethylhexyl acrylate and α
A mixture of 20 parts of α゛-azobisdimethylvalerotril was dropwise polymerized over 4 hours. After aging at the same temperature for 10 hours after the dropwise addition, the temperature was gradually raised to 210°C while the pressure was reduced to 2 mmHg, xylene was distilled off, and the molten resin was taken out into a stainless steel vat, left to cool, pulverized, and powdered. type of resin (Koka type flow tester softening point 12
4°C, Tg 65.0°C).

After mixing 93 parts of the resin and 7 parts of carbon black (SU-GAL 400R manufactured by CABOFT) in a ball mill, kneading,
It was crushed and classified to obtain a toner with an average particle size of 13.2 μm. The amount of charge of the obtained toner was +15 μc/g.

A developer was prepared by mixing 91 g of the toner with 1209 g of carrier iron powder, and an image was produced using the same evaluation machine as in Example 1. A clear image was obtained without background smudges, bleeding, or missing solid black areas. It was done. When the fixing temperature of the fixing device was controlled and the image fixing and offset properties were evaluated, the result was 1.
It was fixed at 48°C and no hot offset occurred.

When images were printed up to 50,000 sheets, clear images were obtained without any visible blurring or missing solid black areas.

Example 3 In the reactor of Example 1, 500 parts of xylene, 15 parts of N,N'-dimethyl-N,N'-bis(2-hydroxyethyl)ethylenediamine, 840 parts of styrene, 10 parts of methacrylic acid, and 135 parts of butyl acrylate were added. Part and α.

In the same manner as in Example 1 using 10 parts of α'-azobisdimethylwareconitrile, a powdered resin (softening point of Koka flow tester: 123.0°C, 7 g, 63.2°C) was obtained.

After mixing 93 parts of the resin and 7 parts of carbon black (Su-Gal 400R manufactured by Cabot) in a ball mill, kneading,
Grind and classify, average particle size: 13. A toner of Oμ was obtained. The amount of charge of the obtained toner was +14 μc/g.

Mixing 91 g of the toner with 1209 g of carrier iron powder,
When a developer was prepared and an image was produced using the same evaluation machine as in Example 1, a clear image was obtained without background smudges, bleeding, or missing solid black areas.

Controls the fixing temperature of the fixing device to improve image fixability,
When evaluating the offset property, it was fixed at 145℃,
No hot offset occurred. When images were printed up to 50,000 sheets, clear images were obtained with no visible blurring or black solid areas.

Example 4 In the reactor of Example 1, 500 parts of xylene, 2-methyl-2
- Using 15 parts of N,N-dimethylaminomethyl-1,3-propanediol, 855 parts of styrene, 10 parts of methacrylic acid, 120 parts of uryl methacrylate, and 10 parts of α,α°-azobisdimethylvalerotrile. So, Example 1
A powdered resin (softening point of Koka type flow tester: 123.6°C, Tg: 62.3°C) was obtained in the same manner as above.

After mixing 93 parts of the resin and 7 parts of carbon blank (Su-Gal 400R manufactured by Cabot) in a ball mill, kneading,
It was crushed and classified to obtain a toner with an average particle size of 13.2 μm. The amount of charge of the obtained toner was +16 μc/g.

Mixing 91 g of the toner with 1209 g of carrier iron powder,
When a developer was prepared and an image was produced using the same evaluation machine as in Example 1, a clear image was obtained without background smudges, bleeding, or missing solid black areas.

Controls the fixing temperature of the fixing device to improve image fixability,
When evaluating the offset property, it was fixed at 144℃,
No hot offset occurred. When images were printed up to 50,000 sheets, clear images were obtained without any visible blurring or missing solid black areas.

Example 5 In the reactor of Example 1, 500 parts of xylene, 13 parts of the following epoxy compound, 837 parts of styrene, 10 parts of acrylic acid, 140 parts of butyl acrylate, and 20 parts of α,α''-azobisdimethylwareconitrile were used. Then, in the same manner as in Example 1, a powdered resin (softening point 125.4°C using Koka type flow tester) was prepared.
, Tg 65.2°C).

After mixing 93 parts of the resin and 7 parts of carbon black (SU-GAL 400R manufactured by CABOSOTO) in a ball mill, kneading,
It was crushed and classified to obtain a toner with an average particle size of 13.7 μm. The amount of charge of the obtained toner was +16 μc/g.

Mixing 91 g of the toner with 1209 g of carrier iron powder,
When a developer was prepared and an image was produced using the same evaluation machine as in Example 1, a clear image was obtained without background smudges, bleeding, or missing solid black areas.

Controls the fixing temperature of the fixing device to improve image fixability,
When evaluating the offset property, it was fixed at 146℃,
No hot offset occurred. When images were printed up to 50,000 sheets, clear images were obtained without any visible blurring or missing solid black areas.

Comparative Example I A resin (Koka flow tester, softening point 128.4°C, Tg
66.0°C) was obtained.

After mixing 93 parts of the resin and 7 parts of carbon black (SU-GAL 400R manufactured by CABOSOTO) in a ball mill,
It was crushed and classified to obtain a toner with an average particle size of 13.0 μm. When the obtained toner was mixed with carrier iron powder and the amount of charge was measured using a blow-off measuring device, it was found to be -7 μc/g.

Claims (1)

[Scope of Claims] 1. An electrophotographic developer containing a binder resin and a colorant as main components, in which the main components of the binder resin are (a) styrene and/or a styrene derivative, and (b) methacrylic acid. , acrylic acid, and one or more monomers selected from these esters, (c) a dihydric or higher alcohol having a tertiary amino group and/or a tertiary amino group. An electrophotographic developer characterized by being a resin reacted with an epoxy compound. The component 2 (c) is a dihydric or higher alcohol having a tertiary amino group represented by the following general formulas [I] to [IV], and the amount used is 0.05 based on the total amount of monomers. 50% by weight, and the number of moles used does not exceed the number of moles of component (b). ▲There are mathematical formulas, chemical formulas, tables, etc.▼……[I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼……[II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼……[III] ▲Mathematical formulas, chemical formulas, There are tables, etc.▼...[IV] (In formulas [I] to [IV], R_1, R_2, R_3, R
_4, R_5, R_6, R_7, R_8, R_9,
R_1_0, R_1_1, R_1_2, R_1_3, R
_1_4, R_1_5, R_1_6 are alkylene groups having 1 to 15 carbon atoms, R_3 and R_4 are alkyl groups having 1 to 10 carbon atoms, R_1_7 and R_1_8 are alkyl groups having 1 to 4 carbon atoms, and R_1_7 and R_1
_8 may form a different ring of the same nitrogen atom. R_1_5 represents an alkyl group having 1 to 3 carbon atoms or ▲Numerical formula, chemical formula, table, etc. are available▼. X represents a hydrogen atom or a hydroxyl group. ) 3 The softening temperature of the resin using a high-performance flow tester is 10.
The electrophotographic developer according to claim 1, which has a glass transition temperature of 0 to 160°C and a glass transition temperature of 50°C or higher.