JPS6368854A - Electrophotographic developer composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition capable of preventing offset, without applying any offset preventing solution by using a specific polyester resin contg. a vinyl type resin to a main component of a binding resin of the titled composition, and by incorporating at least two kinds of electric charge controlling agents to the titled composition. CONSTITUTION:The main component of the binding resin obtd. in the titled composition is composed of the polyester resin contg. the vinyl type resin which has <=11,000 a number average molecular weight and a glass transition temp. of 50-100 deg.C, and contains 5-42wt% of the vinyl type resin in 100wt% of the polyester resin. The polyester resin part is composed of the polyester resin obtd. by effecting a condensation polymerization of a diol component shown by formula I, a bivalent carboxylic acid or its acid anhydride or its lower alkylester, and a trivalent or more polyvalent carboxylic acid, its acid anhydride, or its lower alkylester, or/and a trivalent or more polyhydric alcohol. The polyester resin contg. the vinyl type resin has >=1.2 OHV/AV (wherein, AV is the acid value and OHV is the hydroxyl value). The titled composition contains at least two kinds of the electric charge controlling agents.

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, and the like.

[Conventional technology and problems]

Conventional electrophotographic methods include uniformly charging a photoconductive insulating layer, then exposing the layer to light, as described in U.S. Pat. An electrical latent image is formed by dissipating the electric charge on the part, and is made visible by attaching a colored, electrically charged fine powder called toner to the latent image (development process). After the visible image is transferred to a transfer material such as transfer paper (transfer process), heating,
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 during copying of tens 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 difficult to achieve sufficient fixation. 1 - It is necessary to raise the temperature of the roller, which not only causes problems such as deterioration of the fixing device, curling of paper, and increased energy consumption, but also has poor pulverization properties when using such resins, so toner When manufacturing, the manufacturing efficiency is significantly reduced. 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 constant fixing method, the JJtl heat roller surface and the toner image surface of the fixing sheet 1- are in pressure contact, so the thermal efficiency is extremely high and it is widely used from low speeds to high speeds. When the image planes come into contact,
The toner adheres to the heating roller surface (&'li
The so-called offset phenomenon is likely to occur when the image is transferred to a transfer paper or the like. In order to prevent this phenomenon, the surface of the heating roller is treated with a material with excellent mold release properties such as a fluorine-based resin, and in addition, a mold release agent such as silicone oil is coated on the surface of the heating roller.

However, the method of applying silicone oil or the like is not preferable because the fixing device becomes large and not only expensive but also complicated, which tends to cause trouble.

Also, Japanese Patent Publication No. 55-6895, Japanese Patent Publication No. 56-98202
As described in the above publication, there is a method of improving the offset phenomenon by widening the molecular weight distribution width of the binder resin, but generally the degree of polymerization of the resin increases and the fixing temperature used also needs to be set high.

A further improved method is a method of improving the offset phenomenon by making the resin asymmetrical and crosslinking, as described in Japanese Patent Publication No. 57-193, Japanese Patent Application Publication No. 50-44836, and Japanese Patent Application Publication No. 57-37353. However, the retention point has not improved.

Generally, the minimum fusing temperature is between the low temperature offset and the high temperature offset, so the usable temperature range is between the minimum fusing temperature and the high temperature offset. ”
By increasing the temperature, the fixing temperature used can be lowered and the usable temperature range can be expanded, resulting in energy savings and
Fast fixing and can prevent paper from curling.

In addition, in order to be able to make double-sided copies without any trouble, the copiers have become more intelligent, the temperature control of the fixing device has become more accurate, and
There are many advantages such as relaxing the tolerance range.

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

When using a styrene-based binder resin to meet such requirements, Japanese Patent Application Laid-Open Nos. 49-65232 and 1977-
As described in No. 28840 and JP-A No. 50-81342, a method of adding paraffin wax, low molecular weight polyolefin, etc. as an offset preventing agent is known, but if the amount added is small, there is no effect, and if there is a large amount, the developer It has also been confirmed that the deterioration of

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-57-109875, polyester resins with improved anti-offset properties using polyhydric carboxylic acids have sufficient properties for use. There is a problem in that either they do not have anti-offset properties, or those that do do so at the expense of the low-temperature fixing properties that polyester resins inherently have. On the other hand, toners using polyester resins may have poor fluidity compared to styrene-based toners, and tend to aggregate, resulting in poor toner transportability within the developing device.
The developability deteriorated, and visible images with poor image quality, such as image unevenness and ground smearing, were sometimes formed.

In order to improve the fluidity of toner, a large amount of fluidity improver such as hydrophobic silica fine powder is added, but as a result, the surface of the electrostatic image support cannot be cleaned with a urethane rubber blade or the like. If this is done, toner particles may become trapped between the blade and the electrostatic image support, resulting in poor cleaning and smearing of the visible image.
In addition, when the developed but untransferred toner is returned to the developing device for reuse or when an image forming apparatus having a cycle system is used, fine particles of hydrophobic silica are embedded in the surface of the toner particles. Toner fluidity was reduced and visible images of poor quality were sometimes formed.

Further, the polyester resin itself has appropriate triboelectric charging properties, and therefore it is possible to impart charging ability to the toner without adding a charge control agent. However, since the entire resin is charged, its frictional charging properties gradually increase.For example, as more than 50,000 copies are made continuously, the amount of charge of the toner using polyester resin changes, and the image density decreases. This may have a negative effect on the visible image, such as making it thinner.

The present invention was made to meet these demands, and its purpose is to prevent offset without applying an anti-offset liquid in a heat roller fixed fixing method.
Another object of the present invention is to provide a developer that 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 blocking, and has a long life (hard to deteriorate).

A further object of the present invention is to provide a resin and a toner with good crushability.

[Means for solving problems]

That is, in the present invention, the main component of the binder resin has a number average molecular weight of 1.
1,000 or less and a glass transition temperature of 50 to 10
A vinyl resin-containing polyester resin containing 5 to 42% by weight of a vinyl resin having a temperature of 0°C based on 100% by weight of the polyester resin, the polyester resin portion having the following formula (in which R is ethylene). or a propylene group, X.

Each y is an integer of 1 or more, and the average value of x and y is 2 to 7. ) a diol component represented by (b) a divalent carboxylic acid or its acid anhydride or its lower alkyl ester; (c) a trivalent or higher polyhydric carboxylic acid or its acid anhydride or its lower alkyl ester; or (and) a polyester resin cocondensed with a trihydric or higher polyhydric alcohol, wherein the vinyl resin-containing polyester resin has an acid value of AV and a hydroxyl value of 0I.
An electrophotographic developer comprising a vinyl resin-containing polyester resin having an OHV/AV (7) value of 1.2 or more when expressed as IV, and containing at least two types of charge control agents. The invention relates to a drug composition.

In the present invention, in particular, the softening point of the binder resin is 106 to 16.
At 0°C, the glass transition temperature is preferably 50 to 80°C, and as for the charge control agent, at least one type of positively chargeable charge control agent and at least one type of negatively chargeable charge control agent are used. It is preferable that the amount of the positively chargeable charge control agent be used is 172 or less of the amount of the negatively chargeable charge control agent used.

When producing polyester resin, carboxyl groups and/or hydroxyl groups remain at the molecular ends of polyester unless a transesterification reaction or a monovalent carboxylic acid and/or alcohol reaction are carried out, but depending on the amount of these terminal groups, It has been confirmed that the amount of triboelectric charge of the polyester resin itself changes. If the amount of terminal groups, especially the acid value, is reduced too much, the amount of F71 triboelectric charge of the polyester resin will decrease,
Furthermore, if the amount of terminal groups, especially the acid value, is increased too much, the amount of triboelectric charge of the polyester resin will increase to a certain level, but on the other hand, the environmental dependence after forming into a toner will become significant, making it difficult to use it as a developer composition. . Acid value: 5-60 (KOt1m
g/g) is often used for toners. Now, the acid value of polyester resin is AV
Although the reason is not strictly elucidated, toners made of polyester resins with a value of 0IIV/AV of 1.2 or more, when hydroxylization is defined as OHV, have good fluidity. By using toner, it has become possible to lower the minimum fixing temperature.

Further, in the present invention, a vinyl resin is contained in the binder resin in order to improve the pulverizability of the binder resin and thus the toner, but ultimately the value of 0) IV/AV of the binder resin is 1. 2
It has also been found that the above conditions do not adversely affect the fluidity of the toner.

The polyester moiety in the resin used as the main component of the binder resin in the present invention is obtained by condensation polymerization of alcohol and carboxylic acid, carboxylic acid ester, or carboxylic acid anhydride. As a diol component, 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, polyoxypropylene(2,0)-polyoxyethylene(2,0)-2,2-bis(4-hydroxyphenyl)propane, polyoxy Propylene (6)-2,2
-bis(4-hydroxyphenyl)propane and the like.

In addition, other diols such as ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, L4-butanediol, neopentyl glycol, 1,4-butynediol, 1.5-bentanediol, ■.

Diols such as 6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A1 hydrogenated bisphenol A, and other dihydric alcohols are included in the alcohol component. It can be added in an amount of about 10 mol% or less.

In addition, the (oral) carboxylic acid component in the present invention is as follows:
For example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, cepatic acid, azelaic acid, malonic acid, or n-dodecenylsuccinic acid. , alkenylsuccinic acids such as n-dodecylsuccinic acid, or alkylsuccinic acids, anhydrides and lower alkyl esters of these acids, and other divalent carboxylic acids.

In addition, the trivalent or higher valence polyfunctional lipid monomer (c) in the present invention is a preferable component that improves the offset phenomenon, but
If it is too little, the effect will be weak, and if it is too much, it will be difficult to control the reaction, and not only will it be difficult to obtain a polyester resin with stable performance, but the resin will also become hard and difficult to crush, resulting in a marked drop in toner production efficiency, and the minimum fixing temperature will be high. Undesirable phenomena such as Therefore, the amount of the trivalent or higher valent polyfunctional monomer (c) to be used is preferably 5 to 60 mol% of the total components. Specifically, among the trivalent or higher polyfunctional monomers in (c), alcohol components include sorbitol, 1,2
, 3.6-hexanetetrol, 1.4-sorbitan,
Pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, L2,5-henthanetriol, glycerol, 2-
Examples include methylpropanetriol, 2-methyl-L2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3.5-trihydroxymethylbenzene, and other trihydric or higher polyhydric alcohols. As the carboxylic acid component having a value higher than that of L2,4-
Benzenetricarboxylic acid, 1,2.5-benzenetricarboxylic acid, 2,5.7-naphthalenetricarboxylic acid, L
2,4-naphthalenetricarboxylic acid, 1゜2.4-butanetricarboxylic acid, L2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1.2.4-cyclohexane tricarboxylic acid, tetra(methylenecarboxyl)methane,
L2,7.8 = octane tetracarboxylic acid, pyronoliso 1-acid, empol trimer acid, anhydrides of these acids, lower alkyl esters, and other trivalent or higher carboxylic acids can be mentioned.

Further, the acid value and hydroxyl value of the resin are measured by the method specified in JIS K 0070, but when the ethyl acetate insoluble content is 3% by weight or more, it is desirable to use dioxane as the acid value measurement solvent.

In the present invention, when the acid value is AV and the hydroxyl value is 011v, a vinyl resin-containing polyester resin having an OHV/AV value of 1.2 or more is used as the main component of the binder resin.
Toner obtained using a resin with an HV/AV value of less than 1.2 has a higher minimum fixing temperature than a toner obtained using a resin with an HV/AV value of 1.2 or more, and in addition, has poor fluidity (and insufficient fluidity). In order to obtain good fluidity, it is necessary to add a large amount of a fluidity improver such as hydrophobic silica fine powder, and in this case, as described above, visible images with poor image quality are often formed.

The vinyl-based resin-containing polyester resin having an OHV/AV value of 1.2 or more as described above can be easily obtained by using the alcohol component in a larger number of functional groups than the carboxylic acid component in the polycondensation reaction described above. .

Further, in the present invention, if the vinyl resin contained in the binder resin has a number average molecular weight of 11,000 or less, the binder resin,
Therefore, it becomes possible to improve the crushability of the toner.

To mix polyester resin and vinyl resin, for example, there is a method of dissolving them in a common solvent, mixing them, and then distilling off the solvent. It is preferable to add the polyester raw material monomers below and proceed with the reaction because the vinyl resin can be dispersed well. However, if the two resin powders are mixed together to form a toner, the image quality may be adversely affected, such as a decrease in image density or the occurrence of background smudges, so the temperature of the powders is unfavorable.

Furthermore, even if a vinyl resin with a number average molecular weight exceeding 11,000 is used, it is not effective in improving the crushability of the binder resin, and even if the number average molecular weight is 11,000 or less, the content is less than 100% of the polyester resin. If it is less than 5% by weight, it will not be effective in improving the crushability, and if it exceeds 42% by weight, it will cause a decrease in image quality after forming into a toner, which is not preferable.

Typical monomers used to form vinyl resins include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, alpha-methylstyrene, p-ethylstyrene, 2,4- Ethylenically unsaturated monoolefins such as dimethylstyrene, p-chlorostyrene, vinylnaphthalene, such as ethylene, propylene, butylene, isobutylene, etc., such as vinyl chloride, vinyl bromide,
Vinyl esters such as vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, etc., such as acrylic acid, methyl acrylate, ethyl acrylate, ln-propyl acrylate, isopropyl acrylate, n-butyl acrylate , isobutyl acrylate, tert-butyl acrylate, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxy acrylate Ethyl, 2-hydroxyethyl acrylate, glycidyl acrylate, 2-acrylate
Chlorethyl, phenyl acrylate, methyl α-chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, Amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, methacrylic acid Ethylenic monocarboxylic acids and their esters such as glycidyl, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc., substituted ethylenic monocarboxylic acids such as acrylonitrile, methacrylonitrile, acrylamide, etc., dimethyl maleate etc., vinyl ketones such as vinyl methyl ketone, vinyl ethers such as vinyl methyl ether, vinylidene halides such as vinylidene chloride, e.g. N-vinylpyrol, N-vinyl There are N-vinyl compounds such as pyrrolidone and the like.

Further, known crosslinking agents such as divinylbenzene can also be used.

A vinyl resin is obtained by addition polymerizing the above monomers, but preferably a radical polymerization method is used, and in order to reduce the number average molecular weight to 11,000 or less, a large amount of polymerization initiator is used, This can be easily achieved by using a chain transfer agent.

Furthermore, the glass transition temperature of the vinyl resin in the present invention is 5
The temperature is preferably 0 to 100°C, and if it is less than 50°C, it will adversely affect the storage stability of the toner, and if it exceeds 100°C, it will adversely affect the fixing properties.

The binder resin whose main component is the vinyl resin-containing polyester resin used in the present invention is as follows:
Softening point is 106-160℃, glass transition temperature is 50-8
A softening point of 0° C. is preferable, but if the softening point is less than 106° C., it is not effective in obtaining a sufficient non-offset region, and if it exceeds 160° C., undesirable phenomena such as an increase in the minimum fixing temperature occur. On the other hand, if the glass transition temperature is less than 50°C, the storage stability after forming a toner will be poor, and if it exceeds 80'C, it will adversely affect the fixing performance, which is not preferable.

The developer composition of the present invention contains the above-mentioned vinyl resin-containing polyester resin and at least two types of charge control agents, preferably one or more of each of positively chargeable and negatively chargeable, and has a positive chargeability. By keeping the amount of control agent used at 172 or less of the amount of negatively chargeable charge control agent used, good visible images can be obtained without loss of density even when 50,000 or more copies are made continuously. became possible.

Specific examples of positively chargeable charge control agents include nigrosine dyes, such as "Nigrosine Base IEXJ,""Oil Black BSJ,""Oil Black Sol,""BontronN-01J,""BontronN-11J" (Orient Chemical Co., Ltd.) triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salt compounds such as "Bontron P-51" (manufactured by Orient Chemical Co., Ltd.), cetyltrimethylammonium bromide, polyamine resins, e.g. Other examples include rAFP-B J (manufactured by Orient Chemical Co., Ltd.).

Specific examples of negatively chargeable charge control agents include metal-containing azo dyes, such as [Pari Fast Black 3804 J, "
Bontron S-31J, [Bontron S-32J, [Bontron S-34J, "Bontron 5-36" (above,
(manufactured by Orient Chemical Co., Ltd.), “Eisenspiron Black T
V) Copper phthalocyanine dyes, metal complexes of alkyl derivatives of salicylic acid such as IJ (manufactured by Odugaya Kagaku Co., Ltd.), e.g.
Bontron E-82", "Bontron E-84J, [Bontron E-85J (manufactured by Orient Chemical Co., Ltd.), etc.]
Others can be mentioned.

The above charge control agent has a charge control agent of 0.1 to 8.0 with respect to the binder resin.
It is contained in an amount of 0.2 to 5.0% by weight, preferably 0.2 to 5.0% by weight.

The polyester portion in the binder resin used in the present invention can be produced by condensation polymerization of a polyhydric carboxylic acid component and a polyol component at a temperature of 180 to 250° C. in an inert gas atmosphere. At this time, commonly used esterification catalysts such as zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate, etc. can be used to accelerate the reaction. It can also be produced under reduced pressure for the same purpose.

A toner is obtained by using the vinyl resin-containing polyester resin according to the present invention as the main component of the binder resin, but in addition to adding a colorant and a magnetic substance during toner preparation, wax is added as an anti-offset agent, and as a fluidity improver. A property improver such as hydrophobic silica is added, but when the vinyl resin-containing polyester resin according to the present invention is used as a binder resin, it is not necessary to add the property improver, and even if it is added, The amount added can be small.

Colorants used in the present invention include various carbon blanks manufactured by thermal black method, acetylene black method, channel blank method, lamp black method, etc., phthalocyanine blue, permanent brown F.
C, Brilliant First Scarle Soto, Pigment Green B10-Damine-B Base, Truben 1-Red 49, Solvent Red 146, Solvent Blue 3
5, etc., and mixtures thereof, etc., and are usually used in an amount of 1 to 15 parts by weight per 100 parts by weight of the binder resin.

In the present invention, after uniformly dispersing the above-mentioned vinyl resin-containing polyester resin and at least two types of charge control agents as essential components, and a coloring agent and optionally a property improving agent,
After melting, kneading, cooling, pulverizing, and classifying by a known method, a toner having an average particle size of 5 to 15 μm is obtained. It can be used as a dry two-component developer by mixing with a type carrier or the above carrier coated with a resin or the like.

When making a magnetic toner using the binder resin according to the present invention,
Examples of the magnetic material include powders of ferromagnetic metals such as iron, cobalt, and nickel, and alloys or compounds containing ferromagnetic elements such as ferrite, hematite, and magnetite, and the magnetic material has an average particle size of 0.1 It can be used in the form of a fine powder of ~1 .mu.m, by scattering about 40 to 70 parts by weight on 100 parts by weight of the binder resin.

〔Example〕

Examples of manufacturing the binder resin and examples of the present invention will be described below, but the present invention is not limited to these examples.

It should be noted that all composition ratios shown in the production examples and examples are expressed in parts by weight.

Production Example 1 Consisting of 84 parts of styrene and 16 parts of 2-ethylhexyl acrylate, glass transition temperature 62°C, number average molecular weight 8.0
00 styrene-acrylic resin, 840 g of polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene (2
)-2,2-bis(4-hydroxyphenyl)propane 195 g, terephthalic acid 249 g.

7? -132 g of 1,2,5-benzenetricarboxylic acid, 29 g of diptyltin oxide, and 1.5 g
of hydroquinone was placed in a 2-piece glass four-necked flask, equipped with a thermometer, a stainless steel stirring bar, a flowing-down condenser, and a nitrogen inlet tube, and placed in a mantle heater.
The reaction was carried out at 200° C. with stirring under a nitrogen stream.

The degree of polymerization was monitored from the softening point according to IIsTM E28-51T, and the reaction was terminated when the softening point reached 122°C. The resulting resin was a pale yellow solid, ll5c
The glass transition temperature measured by a differential calorimeter was 65°C. The resin had an acid value of 12 KOl (mg/g) and a hydroxyl value of 24 KOl (mg/g). This resin is referred to as a binder resin (1).

Production Example 2 75 parts of styrene, 25 parts of 2-ethylhexyl methacrylate
glass transition temperature 64°C, number average molecular weight 10
, 500 styrene-acrylic resin, 1050 g of polyoxypropylene (2,2)-2,2-bis(4-hydroxyphenyl)propane.

Using the same equipment and procedure as in Production Example 1, using 339 g of azelaic acid and 157 g of 1,2.4-benzenetricarboxylic acid, the softening point was 122°C, the glass transition temperature was 61°C,
Acid value 16KOHmg/g, hydroxyl value 27KOHmg/
A vinyl resin-containing polyester resin of g was obtained. This resin is referred to as a binder resin (2).

Production Example 3 In the same manner as Production Example 1 except that the styrene-acrylic resin was removed, the softening point was 122°C and the glass transition temperature was 6.
6℃, acid value 14KO+Img/g, hydroxyl value 28KO
t (mg/g) of polyester resin is 11. This resin is referred to as a binder resin (3).

Production Example 4 In the same manner as Production Example 1, except that the amount of terephthalic acid was changed to 280g, the softening point was 122°C, the glass transition temperature was 67°C, the acid value was 22KOl 1mg/g, and the hydroxyl value was 20K.
A vinyl resin-containing polyester resin containing OHmg/g was obtained. This resin is referred to as a binder resin (4).

Production Example 5 In Production Example 1, the reaction was terminated when the softening point reached 105'C, and the glass transition temperature was 63°C and the acid value was 17KOHm.
A vinyl resin-containing polyester resin having a 1-hydroxyl value of 30 KOHmg/g was obtained. The resin is bonded with a binder resin (5
).

Production Example 6 In Production Example 1, except that the styrene-acrylic resin was changed to a styrene-acrylic resin with the same composition and number average molecular weight of 13,000, a softening point of 122°C, a glass transition temperature of 63°C, Acid value 13KOHmg/g, hydroxyl value 26KO)! A polyester resin containing mg/g of vinyl resin was obtained. This resin is referred to as a binder resin (6).

Regarding the binder resins obtained in Production Examples 1 to 6 above, the crushability of the resins was evaluated using the following method, and the results are shown in Table 1.

<Simple Grinding Test> The resin that has undergone the normal grinding process is passed through a sieve to obtain a resin powder that passes through 16 sieves but does not pass through 20 sieves. Precisely weigh 30.00g of the above classified resin powder, grind it for 15 seconds with a coffee mill (PITLrPS +1R-2170 type), pass it through a 32-mesh sieve, and weight (A)'g of the resin that does not pass through. Weigh accurately. The remaining rate is calculated using the following formula % formula % (). The above operation is performed three times and averaged, and the average remaining rate is 0 to 15.0% [◎], 15.1 to 3
0.0% [○], 30.1-45.0% [△],
45.1 to 100% is indicated as [x].

Examples 1 to 3, Comparative Examples 1 to 7 Materials having the following compositions were mixed in a ball mill, then melted and kneaded in a pressure kneader, cooled, and then subjected to the usual crushing and classification process to produce toner with an average particle size of 11μ. Prepared.

<Composition> Example 1 Binder resin (1190 parts) Example 2 Binder resin (2190 parts Carbon black "Regal 400R" 47 parts Example 3 Binder resin +11 90 parts Carbon blank "Regal 400Rj 7 parts Comparative example 1 Binder resin +11 90 parts Carbon black [Regal 400RJ 7 parts Comparative example 2 Binder resin (1) 90 parts Carbon blank "Regal 400Rj 7 parts Comparative example 3 Binder resin +1] 90 parts Carbon blank [Regal 400RJ 7 parts Comparative example 4 Binder resin (3) 90 parts Carbon blank "Regal 400RJ 7 parts Comparative example 5 Binder resin (4190 parts Carbon black [Regal 400Rj 7 parts Comparative example 6) Binder resin (5190 parts Carbon black "Regal 400RJ 7 parts Comparative example 7 Binder resin (6190 parts of carbon black [Regal 400Rj 7 parts or more of the toners obtained in Examples 1 to 3, respectively)
~Toner 3, and the toners obtained in Comparative Examples 1 to 7 are referred to as Comparative Toner 1 to Comparative Toner 7, respectively.

39g each of the above toners and 1261g of resin-coated iron powder
A commercially available electrophotographic copying machine (the photoreceptor is amorphous selenium, the rotation speed of the fixing roller is 255 mm/sec, the temperature of the heat roller in the fixing device is variable, and the oil coating device is 3).

The fixing temperature was controlled at 120° C. to 220° C., and the image fixing properties and offset properties were evaluated, and the results are shown in Table 1.

The minimum fixing temperature here is 15 mm x 7.5 mm on the bottom.
A load of 500 g was placed on a 500 g sand eraser, and the image fixed through the fixing machine was rubbed back and forth 5 times. The optical reflection density was measured using a Macbeth reflection densitometer before and after rubbing, and the fixing rate was determined as defined below. This refers to the temperature of the fixing roller when the temperature exceeds 70%.

However, Comparative Toner 5 has poor toner fluidity and poor toner transportability within the developing device, and as a result, from the initial image,
Image unevenness and background stains occurred.

Comparative toner 6 had a low minimum fixing temperature, but a narrow non-offset area. For comparative toners 1 and 2, the image density began to decrease when the number of continuous copies exceeded 53,000 sheets, and the image density remained low even after 70,000 sheets were printed. Comparison toner 3
Staining occurred from the beginning. Comparative toners 4 and 7 had good fixing properties and toner transport properties, and the visible image quality was good from the initial stage up to 120,000 sheets.
Not only the binder resin used in Comparative Toner 4.7 but also the toner had poor crushability.

On the other hand, Toners 1 to 3 of the present invention had good fixing properties, good pulverization properties, and good toner conveyance properties, and the image quality of visible images was good from the initial stage up to 120,000 sheets.

Procedural amendment band (spontaneous) August 19, 1985 1, Indication of the case Japanese Patent Application No. 1983-213516 2, Name of the invention Electrophotographic developer composition 3, Person making the amendment Relationship to the case Patent applicant (091) Kao Co., Ltd. Company 4, Agent 5, Nakai Building, 1-3 Nihonbashi Yokoyama-cho, Chuo-ku, Tokyo, Column 6 for detailed explanation of the invention in the specification to be amended, Contents of the amendment (1) Description Page 17, lines 9 and 10, "In the condensation polymerization reaction," the next line is "Although it is necessary to take into account the flow of raw material monomers out of the reaction system due to evaporation, sublimation, etc. of monomers, basically... ,
(1) Add 3 lines from the bottom of page 27 r157gJ to “141g”
and corrected

Claims (1)

[Claims] 1. The main component of the binder resin has a number average molecular weight of 11,000.
5% by weight of a vinyl resin with a glass transition temperature of 50 to 100°C based on 100% by weight of the polyester resin.
It is a polyester resin containing vinyl resin containing ~42% by weight, and the polyester resin portion is expressed by the following formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R is an ethylene or propylene group, x, y are each an integer of 1 or more, and the average value of x+y is 2 to 7.) A diol component represented by (b) a divalent carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof; c) A polyester resin obtained by co-condensation polymerization with a trivalent or higher polyhydric carboxylic acid, its acid anhydride, or its lower alkyl ester, or (and) a trivalent or higher polyhydric alcohol, the vinyl resin-containing polyester The acid value of the resin is AV, and the hydroxyl value is OH.
Consisting of a vinyl resin-containing polyester resin whose OHV/AV value is 1.2 or more, where V is
An electrophotographic developer composition comprising at least two types of charge control agents. 2. The softening point of the binder resin is 106 to 160°C,
The electrophotographic developer composition according to claim 1, having a glass transition temperature of 50 to 80°C. 3. The electrophotographic developer composition according to claim 1, wherein the charge control agent comprises at least one positively chargeable charge control agent and at least one negatively chargeable charge control agent. 4. The electrophotographic developer according to claim 3, wherein of the charge control agents, the amount of the positively chargeable charge control agent used is 1/2 or less of the amount of the negatively chargeable charge control agent used. agent composition.