JPH09160285A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image forming method excellent in offset resistance, powder fluidity and resistance against blocking by which an image excellent in strength against scratching can be stably formed without damages by peeling paws in a fixing roll part. SOLUTION: In this method, an electric printing master plate comprising a photoreceptor having a toner fixed image is uniformly electrified and wholly exposed to light, developed, transferred and fixed. In this case, the toner used consists of a binder resin, a coloring agent and a lubricant as the essential components. The binder resin is a styrene-acryl resin containing 25-35wt.% tetrahydrofuran-insoluble component. The lubricant is a modified polyethylene wax produced by graft polymn. of styrene monomers and/or unsatd. carboxylic acid monomers to an ethylene single polymer obtd. by polymn. in the presence of a metallocene catalyst or to an ethylene-based copolymer of ethylene and 3-10C α-olefins.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method by an electronic printing method using a dry toner.

[0002]

2. Description of the Related Art In electrophotography, a toner is attached to an electrostatic latent image formed on a photoconductor made of a photoconductive material by a magnetic brush developing method to develop a photosensitized image. The toner image on the body is transferred onto a transfer material such as paper or sheet and then fixed using heat, solvent, pressure or the like to obtain a permanent image. To form an image with good image quality, the toner is naturally required to function without any problem in all processes such as development and transfer, and in the fixing process, the transferred toner image is defective. It is required that the toner be quickly fixed on the transfer body without causing troubles such as dripping and offsetting. In this way, when copying, each process is fully functional and is completed as a system with stable repeating characteristics.

Conventionally, there has been proposed an electrophotographic method, particularly a method of performing printing by utilizing the above-mentioned steps of development, transfer and the like. For example, the zero printing method described in U.S. Pat. No. 2,560,047 and Japanese Patent Publication No. 43-155.
An electronic printing device described in Japanese Patent No. 4 is known. These electronic printing methods form a powder image on a photoconductive plate, fuse or fix it to form a non-photosensitive insulating image pattern, i.e., a print master, and then uniformly charge it to make it uniform. Irradiate light to hold the charge on the non-photosensitive image area, discharge in the photosensitive non-image area to attach the charged powder to the charged portion of the photoconductive plate to form a powder image, This is a method of transferring this powder image onto an appropriate support, and the above steps are repeated.

As described above, the electronic printing method requires two development steps, that is, development at the time of master production and development at the time of copy printing, and these two development steps are performed by the same developing device. It is desirable to carry out, and it is desirable to develop the master making and copy print making with one type of toner.

In the fixing step, the heat fusion method is most often used as a method for fixing a toner image, but this method is roughly classified into two types, a contact type and a non-contact type. In particular, the contact-type heating roll fixing method has been widely used in commercial copying machines, printers, and the like in recent years because it has high thermal efficiency and enables high-speed fixing. However, in the heating roll fixing method, there is a possibility that toner adheres to the heating roll and an offset phenomenon occurs that stains the next copy. Particularly in high-speed copying, since the amount of heating heat per unit time is increased in order to cope with the increase in fixing speed, the offset phenomenon is more likely to occur. Further, in the heating roll fixing method, a peeling claw is provided in the fixing roll portion to prevent the transfer material, generally paper, from being wound around the roll after passing through the fixing roll. However, when the speed of the copying machine is increased, the stress applied to this part increases, so that peeling failure or
When peeled off, troubles such as an image loss occurring at the tip of the transfer material due to the nail may occur.

Further, when the copied image is re-copied as a document, when the copied image is put into the automatic document feeder of the copying machine, the document is rubbed by the paper feed roller of this device, so that the image is not smeared or soiled. Occur. Further, in the case of a double-sided original or a multicolor original, the first copy image is fixed and then the second copy is performed, but at this time, the image surface is rubbed by the paper feed roller, and bleeding or stains occur on the image. Further, a plurality of originals that have been stacked and temporarily stored in the copying machine are taken out one by one by the paper feed roller for the second copying. Even in this transfer, the back surface of the original and the image surface of the lower original are There is also a problem in that both are rubbed to generate rubbing stains and bleeding on both, which causes deterioration of image quality.

In order to improve these problems, a method of adding low molecular weight polypropylene or polyethylene as a lubricant into the toner has been proposed (Japanese Patent Publication No. 52-3).
304, Japanese Patent Publication No. 52-3305, Japanese Patent Publication No. 5
7-52574, JP-B-58-58664, JP-A-58-59455 and JP-A-60-
151650, etc.). In the toner containing the lubricant disclosed in these publications, although it is effective to some extent in improving the offset resistance due to poor releasability from the heating roll, suppressing peeling nail scratches, improving the rubbing strength of the fixed image, etc.
The effect is not enough. Furthermore, since the compatibility of these polyolefin-based lubricants with the resin component is low, the lubricant forms large domains in the toner, and as a result, the powder fluidity and cohesiveness of the toner are greatly deteriorated.

As a method for solving these problems, a method in which a polyolefin is grafted to a resin so as to be compatible with the resin (JP-A-60-457 and JP-A-60-93).
456, JP-A-60-93457, etc., and a method of dispersing the resin in a resin using a modified polyolefin (JP-A-58-63947, JP-A-59-17775).
No. 0, JP-A-60-3644, JP-A-62-264
14508, JP-A-63-191817, etc.) are known. However, these methods
Although it is possible to improve the dispersibility of the polyolefin and suppress deterioration of powder fluidity, cohesiveness, etc. to some extent, there is a problem in that the originally required effect of improving the mold release ability is lost. Further, in the electronic printing method as well, various problems have conventionally occurred due to the special image forming method.

In the electronic printing method, the chargeability of the print master having a toner image has a great influence on the image quality of the final copy printed matter, particularly the image density. That is, if the charge retention of the toner image on the print master is low, the image density of the copy print is reduced, and thus the high charge retention of the toner image is required. In the production of a print master, the conventional toner for electronic printing is that light generated by uniform light irradiation passes through the fixed image portion and reaches the photosensitive layer, which makes the photosensitive layer conductive.
There is a problem that the charge on the image decreases and the image density decreases.

In order to ensure high charge retention in electronic printing toners, use toners that are sufficiently colored to prevent light from reaching the photosensitive layer of the printing master during uniform exposure. However, it is necessary to add a large amount of carbon black for that purpose. However, if the content of carbon black is increased, electric charges are easily injected into the interface between the toner image and the photosensitive layer, and sufficient charging properties cannot be obtained.

As a solution to the above problems, Japanese Patent Laid-Open No. 4-306663 discloses that the amount of toluene insoluble matter in the binder resin is 25% by weight or more, so that the toner fixed in the image area at the time of producing the print master is fixed. A method has been proposed in which the light-scattering property of the image surface is enhanced, the incident light into the photosensitive layer is reduced, and the insulating property of the image portion is enhanced. According to this method, it is possible to improve the charge retention of the toner in the initial stage and obtain a high-density image free from fog. However, the unevenness of the surface of the printing master exhibiting a high light scattering property is abraded by scavenging (in this case, rubbing by the magnetic brush of the developer) over time, resulting in a decrease in image density. There is. Further, the printing master is required to have sufficient strength to withstand many times of development / transfer, but if the toluene insoluble content of the binder resin is too high, the adhesion of the printing master itself to the carrier becomes poor, A large number of times of printing causes a dropout / image disturbance, which naturally affects the image quality of the duplicate document.

Further, when the above-mentioned polyolefin-based lubricant is used, it may adversely affect the charge retention of the electronic printing system, especially the printing master. Such a lubricant has a component having an extremely low molecular weight, which oozes out on the surface of the toner particles at the time of fixing the printing master, and the property of having an extremely low viscosity makes it possible to smooth the surface undulation that exhibits a high light scattering property. That is the reason. Therefore, the high light scattering property of the resin is suppressed, and as a result, the image density is reduced due to the decrease in the charge retention property.

[0013]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned circumstances in the prior art, and has an object to improve the disadvantages thereof. That is, it is an object of the present invention to provide an image forming method capable of obtaining a stable image over time by producing a print master that has good charge retention and does not deteriorate due to rubbing. .

Another object of the present invention is to rub at a lower temperature, with excellent offset resistance, powder flowability and blocking resistance, and without being damaged by the peeling claw of the fixing roll portion. An object of the present invention is to provide an image forming method capable of forming an image having excellent image strength.

[0015]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that in an electronic printing toner containing a binder resin, a colorant and a lubricant as essential components, the binder resin has a tetrahydrofuran insoluble content of 25 to 35% by weight. % Styrene-acrylic resin, by using a specific polymer polymerized in the presence of a metallocene catalyst as a lubricant modified by graft polymerization, found that the above problems can be solved, The invention was completed.

That is, according to the image forming method of the present invention, an electronic printing master having a toner-fixed image formed on a photoconductor is uniformly charged and exposed on the entire surface, and then developed, transferred and fixed to obtain a copy. As a toner, a binder resin, a colorant, and a lubricant are essential components, and the binder resin is a styrene-acrylic resin containing 25 to 35% by weight of tetrahydrofuran-insoluble matter, and the lubricant is a metallocene-based resin. An ethylene homopolymer obtained by polymerization in the presence of a catalyst or an ethylene copolymer composed of ethylene and an α-olefin having 3 to 10 carbon atoms is added to a styrene monomer and / or an unsaturated carboxylic acid homopolymer. It is characterized by using a toner which is a modified polyethylene wax formed by graft-polymerizing a monomer.

In contrast to the electronic printing method in which the same toner is used for the production of the print master and the production of the copy printed matter as described above, the printing toner containing the binder resin, the colorant and the modified polyethylene wax as essential components. When using, although the details are unknown, powder fluidity in the toner particles,
Even if the modified polyethylene wax is highly dispersed so as not to impair the cohesiveness and chargeability, it can be controlled so as to obtain a sufficient releasing ability. Furthermore, the modified polyethylene wax itself is uniformly distributed on the toner particle surface. Since it is dispersed and does not contain an extremely low molecular weight component, even if it is exposed on the toner particle surface, it does not smooth the undulations of the printing master surface that exhibits high light scattering properties, and the abrasion resistance of the lubricant itself is maintained. Can be fully and uniformly exerted, therefore
It is believed that the high charge retention of the print master can be secured for a long period of time, and as a result, stable and uniform toner image formation can be maintained.

Although the details are not clear, when an ethylene homopolymer or a copolymer is produced by using a metallocene catalyst as in the present invention, degassing is performed under vacuum at a temperature equal to or higher than the melting point. The molecular weight distribution (Mw) can be measured by a method, a method of removing a low molecular weight part by dissolving it in a solvent such as hexane or acetone, or a method of removing the high molecular weight part by precipitating at a specific temperature after completely dissolving in a solvent. / Mn) is controlled, the molecular structure / chain length can be regularly controlled from the time of wax polymerization. Therefore, even in the low molecular weight polyethylene wax as described above, one having a higher density can be used. It can be synthesized, and as a result, the aforementioned effects can be exerted at a higher level, and for the same reason, the molecular weight / distribution and viscosity characteristics can be On to control while balancing each equal easier, it is possible to perform modification also efficiently by graft polymerization as described later.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
First, the toner particles used in the present invention will be described. The toner particles in the present invention have a binder resin, a colorant and a lubricant as essential components, and the binder resin used in the present invention is a styrene-acrylic resin containing a gel component which is a tetrahydrofuran (THF) insoluble component. And the content of tetrahydrofuran insoluble matter is 25 to
It is necessary to use one in the range of 35% by weight, and preferably one in the range of 28 to 30% by weight.
When the tetrahydrofuran insoluble content is higher than 35% by weight, the fixing property of the print master to the carrier by a technique such as flash fixing is markedly impaired, resulting in many defects and image defects. On the other hand, if it is less than 25% by weight, when the printing master is fixed, the surface which imparts a high light scattering property is not undulated and the surface becomes smooth, and the charge retention property is deteriorated.

As the monomer constituting the component of the styrene-acrylic resin in the present invention, examples of the styrene monomer include alkylstyrene such as styrene, α-methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, chlorostyrene and vinylstyrene. And the like. Examples of the acrylic monomer include acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, and acrylic. Acid 2-ethylhexyl, acrylic acid n-
Octyl, phenyl acrylate, methyl methacrylate,
Α-, such as ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, etc.
Examples thereof include methylene aliphatic monocarboxylic acid esters, acrylonitrile, methacrylonitrile, acrylamide, etc., but are not limited thereto.

Particularly preferably used in the present invention are styrene-acrylic acid ester copolymers and styrene-methacrylic acid ester copolymers. Also,
The solution polymerization method or suspension polymerization method can be applied to the synthesis of these copolymers, but the suspension polymerization method is preferably used.

In order to control the tetrahydrofuran insoluble content of the styrene-acrylic resin, it is possible to use a crosslinkable monomer during the polymerization reaction. Examples of the crosslinkable monomer include divinylbenzene, allyl methacrylate, 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate and the like. The total amount of these crosslinkable monomers is 100
It is preferably added in an amount of 0.1 to 1 part by weight, more preferably 0.2 to 0.8 part by weight, based on parts by weight.

In the present invention, the tetrahydrofuran insoluble matter means that the sample is dissolved in tetrahydrofuran (THF) and the insoluble matter is separated by a centrifuge, and the dry weight is expressed as a ratio with respect to the weight of the original resin in% by weight. It represents what is shown and can be obtained as follows.

(1) 25 ml of 200 to 300 mg of sample
Weigh it directly into an Erlenmeyer flask, add 20 ml of THF, and leave it overnight. (2) The content of (1) above is put into a centrifuge tube made of polytetrafluoroethylene. (3) In the Erlenmeyer flask of (1) above, 20 ml of TH was added again.
Wash with F, put in the tube of (2) and total 40 ml
And seal with a film. (4) Rotation speed of the tube of (3) above is 18,000 rp
Spin at 20 ° C. for 10 minutes and perform centrifugation for 20 minutes. (5) Take out the tube of (4) and leave it until it returns to room temperature. (6) Weigh 5 ml of the supernatant of the contents of (5) above,
Take out into a weighed aluminum pan, then TH
Evaporate F on a hot plate. (7) The product obtained in (6) above was placed in a vacuum dryer at 50 ° C. and left overnight to dry, and TH was added to 5 ml of TH.
The F-soluble matter is weighed together with the weight of the aluminum dish. (8) The THF insoluble content is calculated by the following formula. [(Sample amount)-{[(THF soluble content + weight of aluminum dish)-(weight of aluminum dish)] x (40 /
5)}] ÷ (sample amount) × 100 = THF insoluble matter (%)

Next, the lubricant which is an essential component of the toner particles in the present invention will be described. The lubricant used in the present invention is an ethylene homopolymer obtained by polymerization in the presence of a metallocene catalyst or ethylene and C3.
A modified polyethylene wax obtained by graft-modifying an ethylene copolymer comprising α-olefin of 10 to 10, wherein the ethylene homopolymer or ethylene copolymer is a styrene monomer and / or an unsaturated carboxylic acid. It is formed by graft-polymerizing a system monomer.

The metallocene catalyst used for synthesizing ethylene homopolymer or ethylene copolymer is
It can be used without any particular limitation. For example, (A) a compound of a transition metal selected from the group consisting of groups IVb, Vb and VIb of the periodic table (hereinafter,
It is called "transition metal compound". ) And (B) a cocatalyst in combination are exemplified. Examples of the above-mentioned transition metal compound include compounds represented by the following general formula (1). ML _x (1) In the general formula (1), M represents a transition metal atom selected from the group consisting of IVb, Vb and VIb groups, and examples thereof include zirconium, titanium and hafnium. x is the valence of the transition metal and represents the number of L. L represents a ligand or group that coordinates to a transition metal, at least one L is a ligand having a cyclopentadienyl skeleton such as cyclopentadienyl, indenyl, and other L is Aliphatic, araliphatic or aromatic hydrocarbon groups having 1 to 12 carbon atoms, alkoxy groups, aryloxy groups, trialkylsilyl groups, SO ₃ R ¹ (provided that R ¹ has a substituent such as halogen. And a hydrocarbon group having 1 to 8 carbon atoms), a halogen atom, and a hydrogen atom. Further, when the compound represented by the general formula (1) contains two or more ligands having a cyclopentadienyl skeleton, the two ligands having a cyclopentadienyl skeleton among them are ethylene and propylene. Alkylene groups such as isopropylidene,
They may be bonded via a substituted alkylene group such as diphenylmethylene, a silylene group, or a substituted silylene group such as a dimethylsilylene group and a diphenylsilylene group.

Examples of such compounds include bis (cyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (ethylcyclopentadienyl) zirconium dichloride, bis (n-propylcyclo). Pentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride, bis (n-
Hexylcyclopentadienyl) zirconium dichloride, bis (methyl-n-propylcyclopentadienyl) zirconium dichloride, bis (methyl-n-butylcyclopentadienyl) zirconium dichloride, bis (dimethyl-n-butylcyclopentadienyl) ) Zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dibromide, bis (n-butylcyclopentadienyl) zirconium methoxychloride,
Bis (n-butylcyclopentadienyl) zirconium ethoxy chloride, bis (n-butylcyclopentadienyl) zirconium butoxycyclolide, bis (n-butylcyclopentadienyl) zirconium ethoxide, bis (n-butylcyclopentadiene) (Enyl) zirconium methyl chloride, bis (n-butylcyclopentadienyl) dimethyl zirconium, bis (n-butylcyclopentadienyl) zirconium benzyl chloride, bis (n-butylcyclopentadienyl) dibenzyl zirconium, bis (n -Butylcyclopentadienyl) zirconium phenyl chloride, bis (n-butylcyclopentadienyl) zirconium hydride chloride, ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) Diethylzirconium, ethylenebis (indenyl) diphenylzirconium, ethylenebis (indenyl) methylzirconium monochloride, ethylenebis (indenyl) ethylzirconium monochloride, ethylenebis (indenyl) methylzirconium monobromide, ethylenebis (indenyl) zirconium dichloride, ethylene Bis (indenyl) zirconium dibromide,

Ethylenebis {1- (4,5,6,7-tetrahydroindenyl)} dimethylzirconium, ethylenebis {1- (4,5,6,7-tetrahydroindenyl)} methylzirconium monochloride, ethylene Bis {1- (4,5,6,7-tetrahydroindenyl)} zirconium dichloride, ethylene bis {1-
(4,5,6,7-Tetrahydroindenyl)} zirconium dibromide, ethylene bis {1- (4-methylindenyl)} zirconium dichloride, ethylenebis {1- (5-methylindenyl)} zirconium dichloride, Ethylene bis {1- (6-methylindenyl)}
Zirconium dichloride, ethylenebis {1- (7-methylindenyl)} zirconium dichloride, ethylenebis {1- (5-methoxyindenyl)} zirconium dichloride, ethylenebis {1- (2,3-dimethylindenyl)} Zirconium dichloride, ethylenebis {1- (4,7-dimethylindenyl)} zirconium dichloride, ethylenebis {1- (4,7-dimethoxyindenyl)} zirconium dichloride, isopropylidene (cyclopentadienyl-fluorenyl) zirconium Dichloride, isopropylidene (cyclopentadienyl-2,7-di-t-butylfluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-methylcyclopentadienyl) zirconium dichloride, dimethylcyclodiene Renbis (cyclopentadienyl) zirconium dichloride, dimethylsilylenebis (methylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (dimethylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (trimethylcyclopentadienyl) zirconium dichloride, dimethyl Examples thereof include silylene bis (indenyl) zirconium dichloride, diphenylsilylene bis (indenyl) zirconium dichloride, and the like. In addition,
In the above examples, the di-substituted cyclopentadienyl ring includes 1,2- and 1,3-substituted compounds, and the tri-substituted compound is 1,2,3- and 1,2,4-substituted compounds. Including the body. In the present invention, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal in the zirconium compound as described above can be used.

As the co-catalyst (B), conventionally known ones can be used without particular limitation. For example, the compound (B-2) which reacts with the aluminoxane (B-1) or the transition metal compound (A) to form an ionic complex can be mentioned.

Specific examples of the aluminoxane (B-1) include organic aluminum compounds represented by the following general formula (2) or (3).

Embedded image (In the formula, R ² represents a hydrocarbon group, and m represents an integer of 2 or more.)

In the above aluminoxane, R ² is methyl group, ethyl group, propyl group, n-butyl group, iso
-Butyl group, phenyl group, phenylmethyl group and the like are exemplified, and methyl group, ethyl group and iso-butyl group are preferable. m is an integer of 2 or more, preferably 3 to 50,
Particularly, it is an integer of 3 to 40.

The aluminoxane can be obtained by, for example, (1) adding a compound containing adsorbed water or a salt containing water of crystallization, for example, to a hydrocarbon medium suspension such as magnesium hydrate and copper sulfate hydrate. A method of reacting an organoaluminum compound such as alkylaluminum to recover it as a hydrocarbon solution, (2) by directly acting water, ice, or steam on the organoaluminum compound such as trialkylaluminum in a medium such as benzene or toluene. There is a method of recovering as a hydrocarbon solution, and the organic aluminum compound used is trimethylaluminum, triethylaluminum, tripropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-aluminum.
Examples include sec-butylaluminum, tri-tert-butylaluminum, triisopentylaluminum and the like.

As the compound (B-2) which reacts with the transition metal compound (A) to form an ionic complex, for example, a compound consisting of a cation and an anion in which a plurality of groups are bound to an element, particularly, Coordination complex compounds can be mentioned as preferable ones. Specific compounds include trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tri (n-butyl) ammonium tetraphenylborate, trimethylammonium tetra (pentafluorophenyl) borate, triethylammonium tetra (pentafluorophenyl) borate,
Tri (n-butyl) ammonium tetra (pentafluorophenyl) borate, Triethylammonium hexafluoroarsenate, Ferrocenium tetraphenylborate, Trityl tetraphenylborate, Ferrocenium tetra (pentafluorophenyl) borate, Methylferrotetra (pentafluorophenyl) borate Cenium, decamethylferrocenium tetra (pentafluorophenyl) borate, silver tetra (pentafluorophenyl) borate, trityl tetra (pentafluorophenyl) borate, silver tetrafluoroborate, silver hexafluorophosphate, silver hexafluoroarsenate , Silver perchlorate, silver hexafluoroantimonate, silver trifluoroacetate, silver trifluorometasulfonate, tetra (pentafluorophenyl) borate (N-benzyl-2
-Cyanopyridinium), tetra (pentafluorophenyl) borate (N-benzyl-3-cyanopyridinium), tetra (pentafluorophenyl) borate (N-benzyl-4-cyanopyridinium), tetra (pentafluorophenyl) borate (N -Methyl-2-cyanopyridinium), tetra (pentafluorophenyl) boric acid (N
-Methyl-3-cyanopyridinium), tetra (pentafluorophenyl) borate (N-methyl-4-cyanopyridinium), trimethylammonium tetra (pentafluorophenyl) borate, trimethyl tetra (pentafluorophenyl) borate (m-trifluoro) Methylphenyl) ammonium, tetra (pentafluorophenyl)
Examples thereof include benzylpyridinium borate.

If necessary, an organoaluminum compound (C) may be used together with these promoters (B). As such an organoaluminum compound, a compound represented by the following general formula (4) can be exemplified. R ¹ _n AlX _3-n (4) (In the formula, R ¹ represents a hydrocarbon group having 1 to 12 carbon atoms;
Represents a halogen atom or a hydrogen atom, and n is an integer of 1 to 3. )

In the above general formula (4), R ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, for example, an alkyl group, a cycloalkyl group or an aryl group. Specifically, a methyl group, an ethyl group, Examples thereof include n-propyl group, iso-propyl group, iso-butyl group, pentyl group, hexyl group, octyl group, cyclopentyl group, cyclohexyl group, phenyl group and tolyl group. As such an organoaluminum compound, trimethylaluminum,
Trialkylaluminums such as triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, tri-2-ethylhexylaluminum; alkenylaluminums such as isoprenylaluminum; dimethylaluminum chloride, diethylaluminium chloride, diisopropylaluminum chloride, diisobutyl. Dialkyl aluminum halides such as aluminum chloride and dimethyl aluminum bromide; alkyl aluminum sesquihalides such as methyl aluminum sesquichloride, ethyl aluminum sesquichloride, isopropyl aluminum sesquichloride, butyl aluminum sesquichloride and ethyl aluminum sesquibromide; methyl aluminum dichloride De, ethylaluminum dichloride, isopropyl aluminum dichloride, alkyl aluminum dihalides such as ethyl aluminum dibromide; diethylaluminum hydride, compounds such as alkyl aluminum hydride such as diisobutyl aluminum hydride are used.

The polymerization reaction of ethylene in the present invention is
A metallocene-based catalyst comprising the above transition metal compound (A) and the co-catalyst (B) and, if necessary, the organoaluminum compound (C) represented by the above general formula (4) is used. The polymerization reaction is carried out in a hydrocarbon medium.
Specific examples of the hydrocarbon medium include butane, isobutane, pentane, hexane, octane, decane, dodecane, hexadecane, octadecane and other aliphatic hydrocarbons, cyclopentane, methylcyclopentane, cyclohexane, cyclooctane and other alicyclic rings. In addition to group hydrocarbons, aromatic hydrocarbons such as benzene, toluene, and xylene, petroleum fractions such as gasoline, kerosene, and light oil, olefin as a raw material also serves as a hydrocarbon medium. Of these hydrocarbon media, aromatic hydrocarbons are preferred.

The ratio of the above-mentioned transition metal compound used when the polymerization reaction is carried out by the liquid phase polymerization method is usually 10 ^-8 to 10 ^-2 gram atom / liter as the concentration of the transition metal atom in the polymerization reaction system. It is preferably in the range of 10 ⁻⁷ to 10 ⁻³ gram atom / liter. The aluminoxane content is usually in the range of 10 ^-4 to 10 ^-1 gram atom / liter, preferably 10 ^-3 to 10 ^-2 gram atom / liter, as the concentration of aluminum atom in the polymerization reaction system. Is. The ratio of aluminum atom to transition metal atom in the polymerization reaction system is usually 4 to 10 ⁷ ,
It is preferably in the range of 10 to 10 ⁶ .

In the present invention, the molecular weight of the ethylene wax can be adjusted by hydrogen and / or the polymerization temperature. The temperature during the polymerization reaction is usually 20 ° C or higher, particularly preferably 50 ° C to 230 ° C. The amount of hydrogen supplied to the polymerization reaction is usually 0.01 to 4, preferably 0.05 to 2, as a molar ratio of hydrogen to ethylene.

In the present invention, an ethylene homopolymer obtained by polymerization in the presence of these metallocene catalysts or an ethylene copolymer comprising ethylene and an α-olefin having 3 to 10 carbon atoms is used. The intrinsic viscosity [η] measured in decalin at 135 ° C is preferably 0.4d.
1 / g or less, particularly preferably 0.005 without 0.35d
1 / g. In the case of a copolymer, the proportion of ethylene in the constituent monomer is usually at least 80 mol%, preferably at least 85 mol%.

Furthermore, the ethylene homopolymer or ethylene copolymer thus obtained has a viscosity average molecular weight of 800 to 3000 and a density of 0.95 g / c.
m ³ or more and penetration of 2 dmm or less, further 1 dmm
It is more preferable that: Polyethylene in this range has self-lubricating properties, and therefore reduces damage due to abrasion of the fixed image surface, and can prevent rubbing stains, bleeding, etc. on the fixed image. That is, after passing through the heating roll, a film having lubricity is formed on the surface of the fixed image, and the lubrication effect is sufficiently exhibited.

The molecular weight distribution (Mw) determined by gel permeation chromatography (hereinafter simply referred to as GPC) of the above ethylene homopolymer or ethylene copolymer (hereinafter simply referred to as polyethylene wax).
/ Mn) is usually preferably 1.1 to 1.8, more preferably 1.5 or less.

When the molecular weight distribution Mw / Mn is in the above range, it is possible to reduce the high molecular weight component and the low molecular weight component in the polyethylene wax within the above-mentioned viscosity average molecular weight range. This eliminates the blocking effect of low molecular weight components that start melting at low temperatures, the deterioration of powder fluidity at room temperature, and the reduction of peel nail damage suppression effect due to the partial increase in melt viscosity of high molecular weight components. It is possible to Further, the molecular weight distribution has a great influence on the melting behavior of the polyethylene wax itself. Generally for polyethylene wax,
In a normal state, it is required to maintain a completely solid state, and when passing through the fixing roll, it is required to completely melt in the vicinity of the set temperature of the fixing roll during the extremely short passage time to exert the effect. When the molecular weight distribution is controlled within the above range, the melting temperature range for finishing the melting can be narrowed as compared with the wax which is usually used. As a result, the amount of wax that contributes to release (the amount of wax that dissolves at the set temperature of the fixing roll) increases, and efficiency is improved from the viewpoint of the effect of manifestation.

Metallocene catalysts produce polymers with a narrower molecular weight distribution than conventional catalyst systems. Therefore, it is not necessary to narrow the molecular weight distribution by the method of distillation, crystallization, and solvent washing, or even if it is necessary, it can be efficiently carried out.

The molecular weight distribution (Mw / Mn) of the polyethylene wax used in the present invention is G as manufactured by Waters Corporation.
It is a value measured using PC150C at a temperature of 140 ° C., solvent o-dichlorobenzene, and a measurement flow rate of 1.0 ml / min at a concentration of 0.1 wt%. In calculating the molecular weight of the sample, the viscosity equation of polyethylene was used. As a column
Tosoh GMH-HT (60 cm) and GMH-HTL
(60 cm) connected was used. The penetration was measured according to JIS K2207, the density was measured according to JIS K6760, and the melt viscosity was measured by heating and melting the sample at 160 ° C. and using a Brookfields viscometer.

The polyethylene wax produced by the above method is further degassed under vacuum at a temperature equal to or higher than the melting point, or dissolved in a solvent such as hexane or acetone to remove the low molecular weight portion, or completely dissolved in the solvent. After that, a method of removing the high molecular weight portion by precipitating at a specific temperature may be used together.

In addition, to the above polyethylene wax,
The graft modification ratio of the styrene-based monomer or unsaturated carboxylic acid-based monomer is preferably 5 to 30 parts by weight when the total weight is 100 parts. Within this range,
There is no adverse effect on powder fluidity, blocking property, caking resistance, etc. due to large domains, release effect due to excessive dispersion of lubricant in toner, reduction in rubbing resistance, etc. Can be shown.

Examples of the styrenic monomer used for graft modification in the present invention include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene,
4-methylstyrene, 2,5-dimethylstyrene, 3,
4-dimethylstyrene, 2,4,6-trimethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4--
Butyl styrene, 4-sec-butyl styrene, 4-t
ert-butyl styrene, 4-hexyl styrene, 4-
Nonylstyrene, 4-octylstyrene, 4-phenylstyrene, 4-decylstyrene, 4-dodecylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 2,4-dichlorostyrene, 3,4-dichlorostyrene, 2-methoxystyrene, 4-methoxystyrene, 4-ethoxystyrene, etc. can be mentioned.

Examples of the unsaturated carboxylic acid type monomer used for graft modification include methyl acrylate, ethyl acrylate, butyl acrylate, sec-butyl acrylate, isobutyl acrylate, propyl acrylate, Isopropyl acrylate, 2-octyl acrylate, dodecyl acrylate, stearyl acrylate, hexyl acrylate, isohexyl acrylate, phenyl acrylate, 2-chlorophenyl acrylate, diethylaminoethyl acrylate, 3-methoxybutyl acrylate, acrylic acid Diethylene glycol ethoxylate,
Acrylic esters such as 2,2,2-trifluoroethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, propyl methacrylate,
Isopropyl methacrylate, 2-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate,
Methacrylic acid esters such as hexyl methacrylate, decyl methacrylate, phenyl methacrylate, 2-chlorophenyl methacrylate, diethylaminoethyl methacrylate, 2-ethylhexyl methacrylate, 2,2,2-trifluoroethyl methacrylate, ethyl maleate. ,
Maleic acid esters such as propyl maleate, butyl maleate, diethyl maleate, dipropyl maleate and dibutyl maleate, ethyl fumarate, butyl fumarate, fumarate esters such as dibutyl fumarate, ethyl itaconate, itaconic acid Examples thereof include itaconic acid esters such as diethyl and butyl itaconate. The styrene-based monomer or unsaturated carboxylic acid-based monomer graft-modified with polyethylene wax has been exemplified above, but the present invention is not limited thereto.

As a method of modifying the above-mentioned monomer into polyethylene wax, various known methods can be adopted. For example, a method in which a polyethylene wax and a styrene-based monomer or an unsaturated carboxylic acid-based monomer are heated and melt-mixed in the presence of a radical initiator and reacted, can be used. In that case, the reaction temperature is 125 to 32.
The range of 5 ° C. is preferable, and as the radical initiator to be used, peroxides such as benzoyl peroxide, lauroyl peroxide, dicumyl peroxide, di-t-butyl peroxide, and azo compounds such as azobisisobutyronitrile are used. Etc.

The melt viscosity of the modified polyethylene wax is preferably 15 to 250 cps at 160 ° C. In this range, the cohesive strength of the fixed image immediately after passing through the heating roll and the melt viscosity of the image surface are appropriately controlled, image scraping by the peeling nail, defective release, and peeling nail scratches due to excessive stress during releasing are generated. Can be suppressed. In particular, when the modified polyethylene wax by the above method has the above viscosity average molecular weight range, the polyethylene wax using the metallocene catalyst as described above has a balance with other wax physical properties due to the advantages of the polyethylene wax. However, there is an advantage that it is easy to control so as to exhibit a desired melt viscosity.

The modified polyethylene wax preferably has a penetration of 2 dmm or less, particularly 1 dmm or less. The modified polyethylene wax having the melt viscosity and the penetration in the above range has self-lubricating property, and therefore reduces damage due to abrasion of the surface of the fixed image and prevents rubbing stains and bleeding on the fixed image. be able to. That is, after passing through the heating roll, a film having lubricity is formed on the surface of the fixed image, and the lubrication effect is sufficiently exhibited.

The amount of the modified polyethylene wax added to the toner is preferably in the range of 1 to 20% by weight, more preferably 3 to 10% by weight, based on the weight of the toner.

Dyes and pigments are used as the colorant which is another one of the main constituents of the toner particles, and examples thereof include carbon black, nigrosine dye, aniline blue, calcyl blue, chrome yellow and ultramarine. Blue, DuPont Oil Red, Quinoline Yellow, Methylene Blue Chloride, Phthalocyanine Blue,
Malachite Green Oxalate, Lamp Black, Rose Bengal, C.I. I. Pigment Red 48: 1,
C. I. Pigment Red 122, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Yellow 97,
C. I. Pigment Yellow 12, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 3 and the like can be illustrated as a typical example. The colorant is not limited to those described above, and may include a known additive such as a charge control agent, if necessary.

The toner particles in the present invention can be obtained by melt-kneading the above-mentioned components by a conventional method, pulverizing and classifying them, but also known methods such as a spray drying method and a suspension polymerization granulation method. Can also be obtained by The average particle size is preferably in the range of 6 to 16 μm.
Further, other inorganic compound fine particles such as a fluidity improver including colloidal silica fine particles may be externally added to the toner particles.

The toner obtained as described above is mixed with a carrier composed of magnetic sensitive particles having a particle size of 50 to 1000 μm in an appropriate ratio to obtain a developer. Iron powder, ferrite powder, nickel powder, etc. are generally used as the magnetically sensitive particles, and an organic polymer layer may be provided on the surface of these particles.

Next, the image forming method of the present invention using the developer containing the above toner will be described. The image forming method in the present invention comprises the steps of forming a fixed toner image on a photoconductor to prepare an electronic printing master, performing uniform charging and overall exposure, and then developing and transferring and fixing. FIG. 1 is a schematic configuration diagram of an electronic printing apparatus for carrying out the image forming method of the present invention. In the figure,
Reference numeral 1 denotes a rotating drum, and a charging device 4, a uniform exposure lamp 13, a developing device 5, a transfer corotron 6, a fixing device 7, a cleaner lamp 15, and a cleaning device 8 are arranged around the rotating drum. The rotating drum 1 has a photosensitive paper 10 around it.
It is designed to be supported by the presser claw. In the production of the electronic printing master, the photosensitive paper 10 is wound around the rotating drum 1 and supported, and then the original on the original table 3 charged by the charger 4 and irradiated by the original illumination lamp 14 is projected by the projection lens 2. It is projected onto the photosensitive paper 10 via the above to form an electrostatic latent image.
Next, the formed electrostatic latent image is developed and visualized by the developing device 5, and the powder toner image formed by the fixing device 7 is fused and fixed on the photosensitive paper 10 to form an electronic printing master. To be done.

The electrostatic printing of a large number of sheets using the electronic printing master formed as described above is performed as follows. An electronic printing master that has a toner image on photosensitive paper is
It is charged by the charger 4 and is further exposed by the uniform exposure lamp 13. The charge on the photosensitive paper 10 that is uniformly charged is
The toner is discharged by uniform exposure, leaving only the insensitive and non-photoconductive toner image portion. Therefore, a print master having an electric charge only in the toner image portion is formed and visualized by the developing machine 5. Next, the transfer paper 11 is the rotating drum 1.
The toner image on the electronic printing master is transferred to the transfer paper by the transfer corotron 6 in synchronism with the rotation of the paper, and becomes a fixed image by the fixing device 9, and the discharge tray 1
A copy is obtained by being guided to 2. On the other hand, the residual toner on the electronic printing master after transfer is cleaned by the cleaner lamp 15 and the cleaning device 8 as necessary, and the first printing cycle is completed. Thereafter, the above printing cycle is repeated depending on the number of copies required.

In the present invention, zinc oxide coated paper is advantageously used as the photosensitive paper 10 because it is inexpensive, but it is not particularly limited thereto. A flash fixing device can be effectively used as the fixing device 7.

[0059]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following description, "part" means "part by weight". (Production of Polyethylene Wax Using Metallocene Catalyst) Production Example A Using a continuous polymerization reactor, 200 liters / hr of purified hexane and 0.4 mol / mol of methylaluminoxane (manufactured by Tosoh Akzo) in terms of aluminum atom / hr, trimethylaluminum 0.2 mol / hr and bis (n
-Butylcyclopentadienyl) zirconium dichloride was continuously supplied at a rate of 2 mmol / hr in terms of zirconium atom, and hydrogen and ethylene ratio (H ₂ / C ₂ H ₄ ) was 0 in the gas phase in the polymerization reactor. .40, total pressure 30
Ethylene and hydrogen were continuously supplied so as to obtain kg / cm ² G, polymerization temperature 140 ° C., atmospheric pressure, residence time 0.5
Polymerization was carried out under conditions such that the polymer concentration was 90 g / liter for an hour. To 1 liter of the obtained polymer solution,
After adding 5 liters of methanol to precipitate the polymer, the polymer was recovered by filtration and dried to obtain a polymer having the following physical properties. [Η]: 0.08 dl / g,
Molecular weight distribution Mw / Mn: 1.3, viscosity average molecular weight: 11
30, density: 0.96 g / cm ³ , melt viscosity at 160 ° C .: 12.0 cps.

Production Example B Same as Production Example A except that in the polymerization reaction of Production Example A, the hydrogen and ethylene ratio (H ₂ / C ₂ H ₄ ) in the gas phase in the polymerization reactor was changed to 0.50. The polymerization reaction was carried out. The physical properties of the obtained polymer were as follows. [Η]: 0.0
6 dl / g, molecular weight distribution Mw / Mn: 1.2, viscosity average molecular weight: 890, density: 0.96 g / cm ³ , 160 ° C.
Melt viscosity at: 7.7 cps.

(Production Examples of Various Graft-Modified Polyethylene Waxes) Production Example 1 Polyethylene Wax Production Example A Using Metatheron Catalyst
Polyethylene wax ([η]: 0.08 dl / g,
Molecular weight distribution Mw / Mn: 1.3, viscosity average molecular weight: 11
30, density: 0.96 g / cm ³ , melt viscosity at 160 ° C .: 12.0 cps) 1000 g were melted at 160 ° C., 250 g of styrene, 21 g of di-tert-butyl peroxide were taken from separate conduits for 4 hours. Was dropped. After the dropping was completed, the reaction was further continued at 160 ° C for 1 hour, and then degassed under a vacuum of 30 mmHg for 1 hour to remove volatile matter, and a modified polyethylene wax (penetration: 1 dmm or less, melting at 160 ° C) was performed. Viscosity: 23.7 cps) was obtained. Production Example 2 Polyethylene Wax Production Example B Using Metacelone Catalyst
Polyethylene wax ([η]: 0.06 dl / g,
Molecular weight distribution Mw / Mn: 1.2, viscosity average molecular weight: 89
0, density: 0.96 g / cm ³ , melt viscosity at 160 ° C .: 7,000 cps) were used in the same manner as in Production Example 1 except that 1000 g of modified polyethylene wax (penetration:
Melt viscosity at 160 ° C. of 1 dmm or less: 17.0 cp
s) was obtained.

Production Example 3 A modified polyethylene wax (penetration: was obtained in the same manner as in Production Example 1 except that a mixture of 125 g of styrene and 125 g of dibutyl fumarate was used instead of 250 g of styrene.
Melt viscosity at 160 ° C. under 1 dmm: 18.0 cp
s) was obtained. Production Example 4 Modified polyethylene wax (penetration: 1 dmm or less, melt viscosity at 160 ° C .: 20) was conducted in the same manner as in Production Example 1 except that a mixture of 125 g of styrene and 125 g of butyl methacrylate was used instead of 250 g of styrene. .0c
ps) was obtained. Production Example 5 Polyethylene wax (viscosity average molecular weight: 1070, molecular weight distribution: Mw / Mn: 2.61, density: 0.97 g /
cm ³ , melt viscosity at 160 ° C .: 85.0 cps) 10
Modified polyethylene wax (penetration: 1 dmm or less, 160 ° C.) in the same manner as in Production Example 1 except that 100 g was used.
Melt viscosity at 210.0 cps) was obtained.

Production Example 6 Instead of 250 g of styrene, 20 g of styrene, di-t
except that 1.7 g of ert-butyl peroxide was used,
In the same manner as in Production Example 1, modified polyethylene wax (penetration: 1 dmm or less, melt viscosity at 160 ° C .: 12.0)
cps). Production Example 7 In the same manner as in Production Example 1 except that a mixture of 125 g of styrene and 540 g of dibutyl fumarate was used instead of 250 g of styrene, a modified polyethylene wax (penetration:
2dmm, melt viscosity at 160 ° C: 130.0 cps)
I got Production Example 8 Polypropylene wax (viscosity average molecular weight: 3000,
Molecular weight distribution: Mw / Mn: 2.75, density: 0.89 g
/ Cm ³ , melt viscosity at 160 ° C .: 70.0 cps) 1
Modified polypropylene wax (penetration: 1 dmm, 180 ° C.) in the same manner as in Production Example 1 except that 000 g was used.
Melt viscosity at 250.0 cps) was obtained.

(Preparation Example of Developer for Electronic Printing) Example 1 (Preparation of Toner) 100 parts of styrene-butyl methacrylate copolymer (80/20) (THF insoluble matter: 25% by weight, Mw = 1.8 ×) 10 ⁵ ) Carbon black (BP1300, manufactured by Cabot Corporation) 10 parts Charge control agent (P-51, manufactured by Orient Chemical Industry Co., Ltd.) 2 parts Modified polyethylene wax shown in Production Example 1 5 parts The above components are melt-kneaded with a Banbury mixer, After cooling, the mixture was finely pulverized by a jet mill and classified by a classifier to obtain toner particles having an average particle diameter of 10 μm. (Preparation of Carrier) Steel shot having a particle diameter of 80 μm was used. (Preparation of Developer) 4 parts of the above toner and 100 parts of carrier were mixed to prepare a developer for electronic printing.

Example 2 An electronic printing developer was obtained in the same manner as in Example 1 except that the modified polyethylene wax shown in Production Example 2 was used as the lubricant. Example 3 An electronic printing developer was obtained in the same manner as in Example 1 except that the modified polyethylene wax shown in Production Example 3 was used as the lubricant. Example 4 A developer for electronic printing was obtained in the same manner as in Example 1 except that the modified polyethylene wax shown in Production Example 4 was used as the lubricant. Example 5 An electronic printing developer was obtained in the same manner as in Example 1 except that the styrene-acrylic resin shown below was used as the binder resin. Styrene-butyl methacrylate copolymer (80/20) 100 parts (THF insoluble matter: 32% by weight, Mw = 2.0 × 10 ⁵ ).

Example 6 (Comparative Example) The following styrene-acrylic resin was used as the binder resin, and polyethylene wax ([η]: 0.13 dl / g, molecular weight distribution Mw / Mn:
2.61, viscosity average molecular weight: 2000, density: 0.97
g / cm ³ , melt viscosity at 160 ° C .: 55.0 cps)
A developer for electronic printing was obtained in the same manner as in Example 1 except that was used. Styrene-butyl methacrylate copolymer (80/20) 100 parts (THF insoluble matter: 0% by weight, Mw = 1.2 × 10 ⁵ ).

Example 7 (Comparative Example) Polypropylene wax as a lubricant (viscosity average molecular weight:
3000, molecular weight distribution Mw / Mn: 2.75, density:
0.89 g / cm ³ , melt viscosity at 160 ° C .: 70.0
A developer for electronic printing was obtained in the same manner as in Example 6 except that cps) was used. Example 8 (Comparative Example) An electronic printing developer was obtained in the same manner as in Example 6 except that the modified polyethylene wax shown in Production Example 5 was used as the lubricant. Example 9 (Comparative Example) An electronic printing developer was obtained in the same manner as in Example 6 except that the modified polyethylene wax shown in Production Example 6 was used as the lubricant. Example 10 (Comparative Example) An electronic printing developer was obtained in the same manner as in Example 6 except that the modified polyethylene wax shown in Production Example 7 was used as the lubricant. Example 11 (Comparative Example) An electronic printing developer was obtained in the same manner as in Example 6 except that the modified polypropylene wax shown in Production Example 8 was used as the lubricant. Example 12 (Comparative Example) Polyethylene wax ([η]: 0.13d as a lubricant)
1 / g, molecular weight distribution Mw / Mn: 2.61, viscosity average molecular weight: 2000, density: 0.97 g / cm ³ , 160 ° C.
Example 1 except that the melt viscosity at 55.0 cps) was used.
A developer for electronic printing was obtained in the same manner as in.

The test methods and evaluation criteria when images were formed using the developers for electronic printing of Examples 1 to 12 are as follows. (1) Offset temperature Measured using a Vivace 550 (manufactured by Fuji Xerox Co., Ltd.) (modified) fixing device. Heat roll temperature 180 ℃
Further, the temperature at which the offset occurred was visually checked by raising the temperature to 250 ° C in 5 ° C increments. (Note that "not generated" is 250 ℃
Indicates that the occurrence of offset is not confirmed. (2) Removal temperature of peeled nail scratches Measured using a Vivace 550 (manufactured by Fuji Xerox Co., Ltd.) (modified) fixing device. It shows the heat roll temperature at which the peeling claw scratches that occur in the solid black image at the tip of the image reach a level where they do not pose a problem in actual use. (It should be noted that "not generated" means that no peeling nail scratches were generated even at the measurement lower limit temperature of 140 ° C.)

(3) Rubbed image intensity: Measured using a Vivace 550 (manufactured by Fuji Xerox Co., Ltd.) (modified). Five originals were set in the apparatus and fed, and the backside dirt of the second and subsequent originals was visually checked and graded. (Note that G0 to G1 are
It means a level that does not pose a problem in actual use. ) G0: No stain on the back G1: Slight stains that are difficult to visually confirm G2: Stain that can be visually confirmed G3: Severe stains that can be sufficiently visually confirmed (4) Storage Stability A standing test was performed for 17 hours in an atmosphere of 50 ° C. and 50% RH. Then, it was subjected to a vibration sieving for 5 minutes with a 63 μm sieve to confirm the blocking property. G1: 63 μm sieve passage rate 70% or more G2: 63 μm sieve passage rate 40% or more, less than 70% G3: 63 μm sieve passage rate less than 40%

(5) Toner Transport Amount The toner particles of each example are used, and Vi is used as an index of powder fluidity.
Vace 800 (manufactured by Fuji Xerox Co., Ltd.) (modified) toner box was used to measure the amount of toner conveyed per hour. (6) Solid Image Density The image densities of the solid image areas collected with a modified XP-100 (manufactured by Fuji Xerox Co., Ltd.) were measured using an X-Rite densitometer. (7) Charge retention property Using a modified XP-100 (manufactured by Fuji Xerox Co., Ltd.),
The potential on the surface of the photoconductor during electronic printing was measured.

Table 1 shows the properties of the lubricant used in the developers for electronic printing of Examples 1 to 12 and Table 2 shows the properties of the binder resin.
Table 3 and Table 4 show the results of the characteristic evaluation.

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

[Table 4]

[0075]

INDUSTRIAL APPLICABILITY In the present invention, a styrene-acrylic resin having a tetrahydrofuran insoluble content of 25 to 35% by weight is used as the binder resin in the toner, and it is obtained by polymerization in the presence of a methaceron catalyst as a lubricant. Ethylene homopolymer or ethylene and α having 3 to 10 carbon atoms
-A toner containing a modified polyethylene wax formed by graft-polymerizing a styrene-based monomer and / or an unsaturated carboxylic acid-based monomer to an ethylene-based copolymer composed of an olefin is used, and thus a high charge is obtained. It becomes possible to secure the holding property, and the offset resistance is good, and the powder fluidity and the blocking resistance are excellent. Therefore, by using it, an image is formed by an electronic printing method. A copy printed matter having excellent image density can be obtained, and the copy printed matter is excellent in rubbing image strength without being damaged by the peeling claw of the fixing roll portion.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electronic printing apparatus used in an image forming method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating drum, 2 ... Projection lens, 3 ... Original platen, 4 ... Charger, 5 ... Developing machine, 6 ... Transfer corotron, 7 ... Fixing machine,
8 ... Cleaning device, 9 ... Fixing device, 10 ... Photosensitive paper,
11 ... Transfer paper, 12 ... Paper discharge tray, 13 ... Uniform exposure lamp, 14 ... Original illumination lamp, 15 ... Cleaner lamp.

Claims (2)

[Claims] 1. An electronic printing master on which a toner-fixed image is formed on a photoreceptor is subjected to uniform charging and overall exposure,
In an image forming method in which a copy is obtained by performing development, transfer, and fixing, a binder resin, a colorant, and a lubricant are essential components as a toner, and the binder resin has a tetrahydrofuran insoluble content of 25%.
To 35% by weight of styrene-acrylic resin, wherein the lubricant is an ethylene homopolymer obtained by polymerization in the presence of a metallocene catalyst or ethylene consisting of ethylene and an α-olefin having 3 to 10 carbon atoms. An image forming method comprising using a toner which is a modified polyethylene wax formed by graft-polymerizing a styrene-based monomer and / or an unsaturated carboxylic acid-based monomer to a resin-based copolymer. 2. The modified polyethylene wax has a density of 0.95 g / cm ³ or more and an average molecular weight of 800 to 3
000, 70 to 95 parts by weight of a polyethylene polymer having a molecular weight distribution Mw (weight average molecular weight) / Mn (number average molecular weight) of 1.1 to 1.8 and a styrene monomer and /
Alternatively, the melt viscosity at 160 ° C. formed by graft-polymerizing 5 to 30 parts by weight of an acrylic monomer is 1
The image forming method according to claim 1, which is a graft-modified polyethylene wax having a penetration of 2 dmm or less at 5 cps to 250 cps.