JPH1083097A - Heat fixable electrophotographic developer and wax - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure superior blocking resistance and releasability at the time of fixation at a low temp., to prevent offsetting phenomenon and to suppress the contamination of a carrier, a photoreceptor, etc., by using a propylene copolymer wax having a specified mol.wt., a specified m.p. and a specified compsn. distribution. SOLUTION: This heat fixable electrophotographic developer contains propylene copolymer wax, a binder and a colorant. The propylene copolymer wax has a wt. average mol.wt. of 3,000-50,000, 120-140 deg.C m.p. and a compsn. distribution (CMn /CMW) of 1.0-2.0, where CMn is ethylene content (mol%) expressed by number - averaged molecular weight and CMW is ethylene content (mol%) expressed by weight - averaged molecular weight. It consists of low and high mol.wt. parts and the ratio of the average ethylene content of the low mol.wt. part to that of the high mol.wt. part is 1.0-1.5. The wax is made of a propylene.ethylene copolymer or a propylene.ethylene.4-12C α-olefin copolymer. The wax is contained by 1-20 pts.wt. based on 100 pts.wt. of thermoplastic resins including the binder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing type electrophotographic developer, and more particularly, to a heat fixing type electrophotographic developer which is used as a main component of electrostatic toner.
This is a heat-fixing type electrophotographic developer that does not cause offset development and does not contaminate the carrier, photoreceptor, heating roller, etc., as a toner having excellent releasability and blocking resistance during heat fixing is obtained. is there.

[0002]

2. Description of the Related Art Electrophotographic developing materials, so-called electrostatic toners, are used in electrostatic electrophotography to develop a latent image formed by charge exposure to form a visible image. This electrostatic toner is a charged fine powder obtained by dispersing a colorant such as carbon black and a pigment in a resin. The electrostatic toner is a dry two-component toner used together with carriers such as iron powder and glass particles, a wet toner dispersed using an organic solvent such as isoparaffin, and a dry toner in which magnetic fine powder is dispersed. They are roughly classified into one-component toners.

By the way, an image obtained by developing on a photoreceptor with an electrostatic toner is transferred to paper, and an image obtained by direct development on a paper having a photosensitive layer formed thereon is not subjected to heat. Or by solvent vapor. Above all, fixing by a heating roller is a contact-type fixing method, and therefore has the advantages of high thermal efficiency, the ability to reliably fix an image even with a relatively low-temperature heat source, and the suitability for high-speed copying. doing.

However, when an image is fixed by bringing a heating element such as a heating roller into contact, the conventional electrostatic toner has a phenomenon that a part of the electrostatic toner adheres to the heating element and is transferred to a subsequent image portion, a so-called offset phenomenon. May occur. In particular, when copying at high speed, it is necessary to raise the temperature of the heating element in order to increase the fixing effect and the fixing speed, and this causes a problem that the offset phenomenon is easily caused. Therefore, for example, when fixing an image formed by one-component electrostatic toner with a heating roller,
The roller surface is impregnated with silicone oil or the silicone oil is supplied to the roller surface to eliminate the offset phenomenon. However, in this case, problems such as contaminated rolls may occur. In order to solve the offset phenomenon, in the invention described in WO 93/16416, while the fixing property (strength) of a toner image to paper is increased by using a high molecular weight component, the softening point becomes higher as the molecular weight becomes higher, and the low temperature fixing property becomes higher. X _R = 1.8
An electrostatic toner which uses a wax having a high molecular weight and a low softening point by suppressing the rise of the softening point while maintaining a high molecular weight by generating a large amount of comonomer-rich low-melting point component by defining it as high as 0 to 2.50. Is disclosed. However, in this case, although the fixing property of the image due to the high molecular weight is relatively excellent,
Since the melting point and softening point tend to be relatively high, there is a problem that the low-temperature offset extinction temperature is also high. X _R = 1.
Since it is as high as 80 to 2.50, the α-olefin (comonomer) content is high in the low molecular weight region, which acts as a solid component, and the toner has poor blocking resistance.

On the other hand, various thermoplastic resins are used as a binder which is a main material of the electrostatic toner.
Low molecular weight styrene- (meth) acrylic acid ester copolymer has good chargeability and suitable softening point (around 100 ° C)
It has good fixing properties, easy cleaning of the photoreceptor and low contamination, low hygroscopicity, good mixing with carbon black as a coloring agent, and easy pulverization. However, the conventional electrostatic toner using a low molecular weight styrene / (meth) acrylic acid ester copolymer or the like also has a problem that an offset phenomenon easily occurs in high-speed copying. In order to solve such a problem, it has been proposed to add a polyolefin wax as a release agent to the electrostatic toner. (JP-B-52-3304, JP-B-52-3305, JP-A-57-52574, JP-A-58-58664, and JP-A-58-59455)

[0006]

However, the aforementioned Japanese Patent Publication No. Sho 5
In the case where the technique described in JP-A 2-3304 is used, a problem different from the offset phenomenon may occur.
That is, the toner to which the polyolefin wax has been added has reduced blocking resistance, and the toner may be blocked in the toner cartridge, and the toner may not be supplied from the toner cartridge onto the photosensitive member. Further, a so-called filming phenomenon in which the low-crystalline substance contained in the wax adheres to the surface of the carrier, the photoconductor, the heating roller, and the like occurs, which causes formation of an electrostatic latent image on the photoconductor and charging of the toner. The image may be adversely affected and the image may be significantly disturbed.

Accordingly, an object of the present invention is to provide a toner which is excellent in releasability at the time of heat fixing, particularly at releasability at low temperature fixing and blocking resistance by using as a main component of the electrostatic toner.
An object of the present invention is to provide a heat fixing type electrophotographic developer which does not cause an offset phenomenon and does not contaminate a carrier, a photoreceptor, a heating roller and the like.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, by using a propylene-based copolymer wax having a specific molecular weight, melting point and composition distribution, The inventors have found that the problem is solved, and have reached the present invention.

That is, the present invention provides a weight average molecular weight (M
w) is from 3,000 to 50,000, and the melting point is from 120 ° C to
140 ° C. and the composition distribution CMn / CMw is 1.0 to
The average ethylene content of 2.0 or lower molecular weight part and (X _L), the average ethylene content of the remaining high molecular weight portion (X _H) and the ratio of _{(X R = X L / X} H) is 1.0 ~ 1.
(5) a heat-fixable electrophotographic developer comprising a propylene copolymer wax (A), a binder (B), and a colorant (C). The present invention also relates to a propylene copolymer wax (A) suitable as a component of the heat fixing type electrophotographic developer. Hereinafter, the heat-fixable electrophotographic developer of the present invention (hereinafter, referred to as
The “developing material of the present invention”) will be described in detail.

Examples of the propylene copolymer wax (A) of the present invention include a propylene / ethylene copolymer and a propylene / ethylene / α-olefin copolymer having 4 to 12 carbon atoms. The α-olefin having 4 or more carbon atoms is preferably an α-olefin having 4 to 12 carbon atoms, and specific examples thereof include butene-1, pentene-1,2
-Methylbutene-1,3-methylbutene-1, hexene-1,3-methylpentene-1,4-methylpentene-
1,3,3-dimethylbutene-1, heptene-1, methylhexene-1, dimethylpentene-1, trimethylbutene-1, ethylpentene-1, octene-1, methylpentene-1, dimethylhexene-1, trimethyl Pentene-1, ethylhexene-1, methylethylpentene-1, diethylbutene-1, propylpentene-1, decene-1, methylnonene-1, dimethyloctene-1,
Trimethylheptene-1, ethyloctene-1, methylethylheptene-1, diethylhexene-1, dodecene-1, hexadodecene-1 and the like.

As the propylene copolymer wax (A), propylene / ethylene copolymer,
A propylene / ethylene / butene copolymer is preferred. The propylene content is usually at least 90 mol%, preferably 91 to
97 mol%.

The propylene copolymer wax (A) of the present invention has a weight average molecular weight (Mw) of 300 measured by gel permeation chromatography (GPC).
It is 0-50000, preferably 5000-40000. In addition, GPC-FTIR is advantageous in that a heat-fixable electrophotographic developer excellent in low-temperature fixability and toner fluidity can be obtained.
The composition distribution (CMn / CMw) measured by
The ratio of the average ethylene content (X _L ) of the low molecular weight part to the average ethylene content (X _H ) of the remaining high molecular weight part (X _H ), preferably from 1.0 to 1.8 or (X _H ) _R
= X _L / X _H) is preferably in the range of 1.0 to 1.5 are those in the range of 1.0 to 1.4.

Here, the composition distribution (CMn / CMw) is obtained by separating the molecular weight of the propylene-based copolymer by high-temperature gel permeation chromatography (GPC) and continuously flowing the obtained molecular weight-fractionated sample into the flow cell. Measure the Fourier transform infrared spectroscopy (FTIR) spectrum,
The ethylene content by molecular weight is measured continuously. From the chromatogram of GPC obtained by this measurement, the point corresponding to the number average molecular weight was determined as the average ethylene content (CMn), and the point corresponding to the weight average molecular weight was determined as the average ethylene content (CMw). CMw).

On the other hand, X_R= X_L/ X_HIs the low molecular weight part
Average ethylene content (X_L) And the remaining high molecular weight fraction
Average ethylene content (X_H), Which is described above.
Echi obtained by chromatogram of GPC
According to the measurement result of the molecular weight of the len content,
Occupies 30% of the total area of the chromatogram
And the average ethylene content of this low molecular weight portion (X_L)
And occupy 70% of the remaining area
Is the high molecular weight part, and the average ethylene of this high molecular weight part
Content (X_H) And X_L/ X_HRatio X_RAsk for
Can be. CMn / CMw and X_L/ X_HThe relationship between
Although not necessarily the same, the propylene-based
If it is limited to a polymer, CMn / CMw × 0.50 + 0.50
≒ X _L/ X_HThere is a relationship. Therefore CMn / CMw =
1.0-2.0 is X_L/ X_H= 1.0 to 1.5
You.

The density of the propylene copolymer wax (measured according to JIS K6760) is 0.88 to 0.88.
0.92, and the softening point (measured according to JIS K2207) is preferably from 125 to 160 ° C. These propylene copolymer waxes may be used alone or
More than one kind may be mixed and used.

The propylene copolymer wax (A) of the present invention can be produced by, for example, a method of producing by copolymerizing propylene / ethylene or propylene / ethylene / α-olefin having 4 to 12 carbon atoms, or a method of producing high molecular weight propylene It can be carried out by any method of heating and degrading the copolymer. In particular, a method using heat degradation is preferable because it can be efficiently produced at a high yield.

As a method for copolymerizing propylene / ethylene and propylene / ethylene / α-olefin having 4 to 12 carbon atoms, a known method is used. For example, a medium / low pressure polymerization method carried out in the presence of various transition metal compound catalysts such as a Ziegler catalyst and a metallocene catalyst can be exemplified.

As a method for heating and degrading a high-molecular-weight propylene-based copolymer, for example, a method for thermally decomposing a high-molecular-weight propylene-based copolymer can be mentioned. The heating temperature at the time of performing thermal decomposition is 300 to 460 ° C, preferably 350 to 450 ° C. The apparatus for performing such thermal decomposition may be any apparatus and is not particularly limited.
For example, an apparatus such as a tubular reactor, a tank reactor, a single-screw or twin-screw extruder may be mentioned, but a tubular reactor is preferably used because heating at a high temperature is easy. Examples of the high-molecular-weight propylene copolymer subjected to heat degradation include propylene / ethylene and propylene / ethylene / carbon number 4
To 12 α-olefin copolymers.

The binder as the component (B) of the heat fixing type electrophotographic developer of the present invention may be any binder as long as it is made of a thermoplastic resin blended in this type of developer. , Is not particularly limited. For example, styrene polymers, ketone resins, maleic acid resins, polyester aliphatic resins, polyester aromatic resins, coumarone resins, phenolic resins, epoxy resins, terpene resins, polyvinyl butyral, polybutyl methacrylate, polyvinyl chloride, polyethylene, polypropylene , Polybutadiene,
Those composed of an ethylene-vinyl acetate copolymer and the like can be mentioned. Among them, a suitable softening point (around 100 ° C)
And a styrene-based polymer having good fixability is preferable.

As the styrene polymer, for example,
A polymer composed of only a styrene-based monomer, a copolymer of a styrene-based monomer and another vinyl-based monomer, and the like can be given. As the styrene monomer, styrene, p-
Chlorstyrene, vinyl naphthalene and the like can be mentioned. Further, as other vinyl monomers, for example, ethylene,
Ethylenically unsaturated monoolefins such as propylene, 1-butene and isobutene; vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride; vinyls such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl acetate Esters: methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-acrylate
Esters of α-methylene aliphatic monocarboxylic acids such as chloro-ethyl, phenyl acrylate, α-methyl methacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate; nitriles such as acrylonitrile, methacrylonitrile, acrylamide Or amides; vinyl methyl ether, vinyl ethyl ether,
Vinyl ethers such as vinyl propyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone and the like N-vinyl compounds and the like can be mentioned. Among these styrene polymers, the number average molecular weight (Mn) is 2000
The above is preferable, and particularly, the number average molecular weight (Mn) is 3
000 to 30,000 are preferred. Further, the styrene-based polymer preferably has a styrene content of 25% by weight or more.

The colorant which is the component (C) of the developing material of the present invention may be any one as long as it is blended in this type of developing material, and is not particularly limited. For example, carbon black, phthalocyanine blue, aniline blue, alcohol oil blue, chrome yellow, ultramarine blue, quinoline yellow, lamp black, rose bengal, diazo yellow, rhodamine B lake, carmine 6
Pigments or dyes such as B and quinacridone derivatives are used, and these can be used alone or in combination of two or more. The colorant (C) may include oil-soluble dyes such as azine-based nigrosine, indulin, azo-based dyes, anthraquinone-based dyes, triphenylmethane-based dyes, xanthene-based dyes, and phthalocyanine-based dyes for the purpose of complementary colors and charge control. May be blended. In the developer of the present invention, the propylene-based copolymer wax (A) and the binder (B)
The mixing ratio of the colorant (C) and the propylene copolymer wax (A) / binder (B) / colorant (C)
Is about 1 to 20/100/1 to 20 by weight, preferably about 1 to 10/100/1 to 10.

The developing material of the present invention contains, besides the propylene copolymer wax (A), the binder (B) and the colorant (C), other components as long as the effects of the present invention are not impaired. May be blended. For example, a charge control material, a plasticizer, and the like may be appropriately compounded.

The developer of the present invention comprises a two-component electrostatic toner,
It is used as a main component of any electrostatic toner such as a one-component electrostatic toner. When the developing material of the present invention is used as a main component of the two-component electrostatic toner, the two-component electrostatic toner contains the propylene-based copolymer wax (A), the binder (B), and the colorant (C). ) And, if necessary, other components are mixed by a known method using a ball mill, an attritor, or the like, and then kneaded using a heated two-roll mill, a heating kneader, an extruder, or the like, and cooled and solidified. Further, the obtained solidified product is roughly crushed using a hammer mill, a crusher, or the like, and then finely pulverized using a jet mill, a vibration mill, or a water-added ball mill, an attritor, or the like.
It can be prepared by adding a carrier to those having a size of μm. The carrier used may be a known carrier and is not particularly limited. Examples thereof include silica sand, glass beads, iron balls, and magnetic material powders of iron, nickel, cobalt, etc., having a particle size of 200 to 700 μm.

The amount of the propylene copolymer wax (A) in the two-component electrostatic toner is determined by the amount of the binder (B)
The amount is 1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin including the above.

When the developer of the present invention is used as a one-component electrostatic toner, the one-component electrostatic toner contains a propylene copolymer wax (A), a binder (B), and a colorant ( C), other additives to be blended as required,
It can be prepared by treating other thermoplastic resin and magnetic material powder in accordance with the same method as in the preparation of the two-component electrostatic toner.

The amount of the propylene copolymer wax (A) in this one-component electrostatic toner is determined by the amount of the binder (B)
1 to 20 parts by weight, preferably 1 to 100 parts by weight
It is an amount that results in a blending of 10 to 10 parts by weight.

As the magnetic material powder to be blended with the one-component electrostatic toner, a fine powder of magnetite having a particle diameter of 1 μm or less is usually used, but metals such as cobalt, iron and nickel, alloys thereof, Powders such as oxides, ferrites, and mixtures thereof can also be used. The compounding amount of the magnetic material powder in this one-component electrostatic toner is good, the electrostatic toner obtained has good electric charge retention without lowering the electrical resistance, and the image does not blur,
In addition, since the softening point is maintained in an appropriate range, fixing can be suitably performed, a required charge value is obtained, and scattering is difficult. Therefore, the sum of the binder (B) and the magnetic material powder is usually used. The amount is such that the ratio of the magnetic material powder is 40 to 120 parts by weight with respect to 100 parts by weight. A known charge control agent may be added to the two-component electrostatic toner or the one-component electrostatic toner as needed.

[0028]

EXAMPLES Examples and comparative examples of the present invention will be described below.
The present invention will be described specifically, but these examples do not limit the scope of the present invention in any way.

(Example 1) [Production of propylene copolymer wax] High molecular weight propylene / ethylene / butene copolymer (using propylene, ethylene and butene as monomers, titanium and electron donor on magnesium chloride) A propylene / ethylene / butene copolymer obtained by copolymerization in the presence of a solid titanium catalyst supporting a polymer having a melt index of 5, a propylene content of 93 mol%, a melting point of 130 ° C., and a CMn / CMw = 1.40.
Abbreviated as -1. ) With a twin screw extruder (screw diameter 30 mm)
φ), and heated and degraded at 400 ° C. while extruding at a screw rotation speed of 25 rpm to produce a propylene / ethylene / butene copolymer wax (hereinafter PW-1).
Abbreviated). Table 1 shows the properties of the obtained propylene / ethylene / butene copolymer wax.

The weight average molecular weight, melting point and composition
Cloth (CMn / CMw), X_R= X_L/ X _HThe measurement of
Performed by law.Weight average molecular weight Waters GPC150C, temperature 140
° C, solvent o-dichlorobenzene, measurement flow rate 1.0 ml /
It was measured at a concentration of 0.1 wt% in min. Sample molecular weight calculation
The sample was prepared using a monodispersed polystyrene standard sample.
The resulting calibration curve was used. As a column, Tosoh Corporation
GMH-HT (60cm) and GMH-HTL (60c
m) were used.Melting point Using a differential scanning calorimeter (DSC), sample at 200 ° C
Up to 10 ° C / min.
The temperature was lowered to 30 ° C. and kept for 5 minutes. After that, the heating rate is 10 ° C / min.
And the endothermic peak observed at this time was taken as the melting point.

Composition distribution (CMn / CMw) Using o-dichlorobenzene as a solvent, a concentration of 0.1
A wt% sample was prepared. Using this sample as a column, GPC using GMH-HT (60 cm) manufactured by Tosoh Corporation
The temperature was 140 ° C. and the measured flow rate was 1.0 ml / m by using an apparatus (using an oven of a temperature rising and eluting fractionation apparatus manufactured by Tosoh Corporation).
The molecular weight fractionation was performed under the conditions of “in”, and the ethylene content (mol%) was continuously measured by a Fourier transform infrared spectrophotometer (FTIR) while continuously flowing the obtained molecular weight fractionated sample into a flow cell. The ethylene content was measured from the shape of the peak that appeared at a wavelength of infrared absorption of 3400 to 2500 cm ^-1 . GP obtained by this measurement
From the C chromatogram, the points corresponding to the number average molecular weight (Mn) were determined by the average ethylene content (CMn) and the weight average molecular weight (Mn).
The point corresponding to w) is determined as the average ethylene content (CMw), and the ratio of CMn / CMw can be obtained. In calculating the molecular weight, a calibration curve prepared from a monodisperse polystyrene standard sample was used. By X _R = X _L / X _H above CMn / CMw of the molecular weight by measurement of the resulting ethylene content when finding, the portion occupied 30% of the area of the total area of the chromatogram of low molecular weight fraction, the low molecular weight The average ethylene content (X _L ) of the portion was determined, and the portion occupying 70% of the remaining area was defined as a high molecular weight portion.
Seeking _H), determining the ratio X _R of X _L / X _H.

[Preparation of Two-Component Electrostatic Toner]
n-butyl methacrylate copolymer (manufactured by Sanyo Chemical Industries,
Hymer SEM-73F) 85 parts by weight, PW-1 4 parts by weight, carbon black (manufactured by Mitsubishi Kasei Kogyo Co., Ltd., Diamond Black SH) 9 parts by weight and gold-containing dye (BASF Corporation, Pomelo Fast Black B) 2 parts by weight, The mixture was supplied to a ball mill and mixed for 24 hours. Next, knead with a hot roll,
After cooling, it was pulverized and classified to prepare a developer having an average particle size of 13 to 15 μm.

A two-component electrostatic toner was prepared by mixing 100 parts by weight of iron powder having an average particle diameter of 50 to 80 μm as a carrier with 120 parts by weight of this developer. Using this two-component electrostatic toner, a copy test was performed by the following method. Table 2 shows the results.

Fixability of Fixed Image Using two-component electrostatic toner manufactured according to the manufacturing example,
Copy test image on selenium photoreceptor by electrophotography,
After developing, the obtained image is transferred to transfer paper, and a fixing roller having a surface formed of polytetrafluoroethylene (manufactured by DuPont) and a silicone rubber KE-1300RTV having a surface formed of
The image was fixed by setting the temperature of the fixing roller to 200 ° C. using a pressure roller formed by Shin-Etsu Chemical Co., Ltd. Then, on the obtained fixed image, the bottom surface on which a load of 500 g was placed was rubbed 5 times with a 15 mm × 7.5 mm sand eraser, and before and after the optical reflection density was measured with a Macbeth reflection densitometer. The fixability of the fixed image was calculated according to the definition of the equation. Fixability (%) = (image density after test) / (image density before test) × 100

Blocking Resistance of Toner 100 g of the two-component electrostatic toner produced according to the production example was placed in a polybin, left standing at 60 ° C. for 50 hours after tapping, returned to room temperature, and the state of blocking was examined. The state of blocking was visually determined according to the following evaluation criteria. ◎ No blocking at all. ○ There is a little blocking that can be easily unraveled. △ There are quite a few blockings that can be easily unraveled by hand. × Many lumps cannot be completely loosened by hand.

A test image is copied and developed on a selenium photoreceptor by electrophotography using a two-component electrostatic toner having a low offset disappearance temperature , and the obtained image is transferred to a transfer paper. A fixing roller made of ethylene (manufactured by DuPont) and a silicone rubber surface (manufactured by Shin-Etsu Chemical Co., Ltd., KE-1300RT)
Using the pressure roller formed in V), the image was fixed by changing the temperature of the fixing roller in various ways. Next, the transfer paper having no toner image was pressed against the fixing roller under the same conditions as described above, and the temperature of the fixing roller at which the low-temperature offset phenomenon disappeared was defined as the low-temperature offset disappearance temperature.

Offset phenomenon, image disorder, and photosensitivity
Body, using a two-component electrostatic toner manufactured according to the heating roller contamination production example,
Copy test image on selenium photoreceptor by electrophotography,
After developing, the obtained image was transferred to a transfer paper, and the surface was formed with polytetrafluoroethylene (manufactured by DuPont).
Fixing roller at 00 ° C and silicone rubber KE-13 on the surface
A copying step of fixing an image using a pressure roller formed of 00RTV (manufactured by Shin-Etsu Chemical Co., Ltd.) was repeated. After repeating the copying process 5000 times, the presence or absence of the offset phenomenon, the presence or absence of image disorder, and the contamination of the photoreceptor / fixing roller surface were examined. The presence / absence of the offset phenomenon and the presence / absence of image disorder were visually determined based on the following surface criteria. ○ There is no problem at all. Δ: Offset phenomenon or image disturbance is very slight. × Offset phenomenon or image disturbance is quite severe.

The contamination of the photoreceptor and the fixing roller was visually determined according to the following evaluation criteria. ◎ It is not dirty at all. ○ Very little dirt is seen. × It is very dirty.

Example 2 A high-molecular-weight propylene / ethylene / butene copolymer (PO-1) was heated and degraded at 425 ° C. in the same manner as in Example 1 to obtain a propylene / ethylene copolymer wax ( PW-2) was produced. PW-
Table 1 shows the properties of No. 2. Next, instead of PW-1, P
An electrostatic toner was prepared and a copy test was performed in the same manner as in Example 1 except that W-2 was used. Table 2 shows the results.

Example 3 A propylene / ethylene / butene copolymer was prepared in the same manner as in Example 1 except that the high molecular weight propylene / ethylene / butene copolymer (PO-1) was thermally degraded at 390 ° C. Wax (PW-3) was produced. Table 1 shows the properties of PW-3. Next, an electrostatic toner was prepared and a copy test was performed in the same manner as in Example 1 except that PW-3 was used instead of PW-1. Table 2 shows the results.

Example 4 Instead of the high molecular weight propylene / ethylene / butene copolymer (PO-1), a high molecular weight propylene / ethylene copolymer (melt index 2) was used.
0, melting point 139 ° C., CMn / CMw = 1.47. Hereafter PO-
Abbreviated as 2. ) Was used in the same manner as in Example 1 to produce a polypropylene wax (PW-4). PW-
Table 1 shows the properties of No. 4. Next, instead of PW-1, P
An electrostatic toner was prepared and a copy test was performed in the same manner as in Example 1 except that W-4 was used. Table 2 shows the results.

Embodiment 5 Instead of PO-1, PO-
A polypropylene wax (PW-5) was produced in the same manner as in Example 2 except that No.2 was used. Table 1 shows the properties of PW-5. Next, an electrostatic toner was prepared and a copy test was performed in the same manner as in Example 1 except that PW-5 was used instead of PW-1. Table 2 shows the results.

Embodiment 6 Instead of PO-1, PO-
A polypropylene wax (PW-6) was produced in the same manner as in Example 3 except that No. 2 was used. Table 1 shows the properties of PW-6. Next, an electrostatic toner was prepared and a copy test was performed in the same manner as in Example 1 except that PW-6 was used instead of PW-1. Table 2 shows the results.

Comparative Example 1 Instead of PO-1, a propylene / ethylene / butene copolymer (melt index: 5, propylene content: 90%, melting point: 120 ° C., CMn / CMw)
= 2.20. Hereinafter, it is abbreviated as PO-3. A propylene / ethylene / butene copolymer wax (PW-7) was produced in the same manner as in Example 1 except that (1) was used. Table 1 shows the properties of PW-7. Next, instead of PW-1, PW-7
The toner was prepared in the same manner as in Example 1 except that the toner was used, and a copy test was performed. Table 2 shows the results.

Comparative Example 2 Instead of PO-1, a propylene / ethylene copolymer (melt index 20, propylene content 93%, melting point 125 ° C., CMn / CMw = 2.
25. Hereinafter, it is abbreviated as PO-4. Example 1 except that) was used.
In the same manner as in the above, a propylene / ethylene copolymer wax (PW-8) was produced. Table 1 shows the properties of PW-8. Next, an electrostatic toner was prepared and a copy test was performed in the same manner as in Example 1 except that PW-8 was used instead of PW-1. Table 2 shows the results.

Comparative Example 3 A propylene / ethylene / butene copolymer wax (PW-9) was produced in the same manner as in Example 1 except that PO-1 was heated and degraded at 440 ° C. Table 1 shows the properties of PW-9. Next, an electrostatic toner was prepared and a copy test was performed in the same manner as in Example 1 except that PW-9 was used instead of PW-1. Table 2 shows the results.

Comparative Example 4 A propylene / ethylene / butene copolymer wax (PW-10) was produced in the same manner as in Example 1 except that PO-1 was heated and degraded at 370 ° C. Table 1 shows the properties of PW-10. Next, an electrostatic toner was prepared in the same manner as in Example 1 except that PW-10 was used instead of PW-1, and a copy test was performed. Table 2 shows the results.

(Comparative Examples 5 to 10)
Examples 1 to 3 and Comparative Examples 1 to 3 of O93 / 16416
Was adjusted and evaluated according to the evaluation criteria described above. Table 2 shows the results.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

The heat-fixing type electrophotographic developer of the present invention comprises:
It is excellent as a main component of the electrostatic toner because it has excellent releasability at low-temperature heat fixing and blocking resistance, has no offset phenomenon, and does not contaminate the carrier, the photoreceptor and the heating roller. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location G03G 9/09 G03G 9/08 321 361

Claims (4)

[Claims] A weight average molecular weight (Mw) of 30 determined by gel permeation chromatography (GPC).
The melting point is from 120 ° C. to 140 ° C. as measured by a differential scanning calorimeter (DSC), and the composition distribution determined by gel permeation chromatography / Fourier transform infrared spectrophotometer (GPC-FTIR). CMn / CMw = 1.0 to 2.0 or low molecular weight partial average ethylene content of the (X _L), the ratio between the average ethylene content of the remaining high molecular weight portion _{(X H) (X R =} X L / _XH )
Contains a propylene-based copolymer wax (A) of 1.0 to 1.5, a binder (B), and a colorant (C). 〔here,
CMn represents the ethylene content (mol%) in the number average molecular weight measured by GPC-FTIR, and CMw represents the ethylene content (mol%) in the weight average molecular weight measured by GPC-FTIR. ] 2. The propylene copolymer wax (A)
Is a propylene / ethylene copolymer or a copolymer of propylene / ethylene and an α-olefin having 4 to 12 carbon atoms, wherein the heat-fixable electrophotographic developer according to claim 1 is used. 3. The propylene copolymer wax (A)
3. The heat fixing type electrophotographic developer according to claim 2, wherein the propylene content of the toner is 90 mol% or more. 4. A weight average molecular weight (Mw) of 30 determined by gel permeation chromatography (GPC).
The melting point is from 120 ° C. to 140 ° C. as measured by a differential scanning calorimeter (DSC), and the composition distribution determined by gel permeation chromatography / Fourier transform infrared spectrophotometer (GPC-FTIR). CMn / CMw = 1.0 to 2.0 or low molecular weight partial average ethylene content of the (X _L), the ratio between the average ethylene content of the remaining high molecular weight portion _{(X H) (X R =} X L / _XH )
Is a propylene-based copolymer wax (A) of 1.0 to 1.5.