JP2806367B2 - Electrostatic image developing toner and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developing toner used for developing an electrostatic latent image in an electrophotographic method and an electrostatic recording method, and an image forming method using the same.

[0002]

2. Description of the Related Art In electrophotography, as a method for fixing a toner image, a heating and melting method is most often used, but this method is roughly classified into a contact type and a non-contact type. In particular, the contact type heat roll fixing method has been widely used in commercial copying machines, printers and the like in recent years because it has good thermal efficiency and can perform high-speed fixing. However,
This heating roll fixing method also has some disadvantages.
As a particularly serious disadvantage, it is pointed out that the amount of energy, that is, the amount of electric power used is considerably larger than that of the pressure roll fixing system. Of course, the fixed image strength of the transfer material such as paper is much better in the heated roll fixing method than in the pressure roll fixing method, and it is also superior in terms of deformation of paper due to pressure, generation of wrinkles, etc. Therefore, it has been studied how to reduce the power consumption in the heat fixing method, in other words, how to lower the minimum temperature required for fixing the toner.

In order to achieve this object, the most effective means include those having a Tg (glass transition temperature) several tens of degrees lower than those commonly used in toner binder resins, those having a low molecular weight, and the like. There is a method using
Many of such toners have a fatal disadvantage that they tend to cause caking and aggregation during storage or in a copying machine. As a measure for solving this drawback, there is an attempt to improve the blocking resistance and fluidity of the toner by adhering very fine particles of colloidal silica, alumina, titania and the like to the toner surface.
This measure does not raise the minimum fixing temperature appreciably and also achieves some improvement in blocking resistance and flowability, which seems to be a seemingly effective means. However, even if these fine particles are subjected to a heat treatment or the like in order to fuse them to the toner surface, they are easily released from the toner surface, and the photoreceptor, particularly, the one whose surface is coated with an organic polymer, etc. It was found to have an adverse effect on this. That is, after many uses, these fine particles are semi-permanently fixed to the surface of the photoreceptor, resulting in an inconvenience of causing image defects. Therefore, this measure cannot be a drastic solution. Furthermore, when the above-described binder resin is used, due to its thermal characteristics, when applied to a heating roll fixing method, toner adheres to the heating roll, causing an offset phenomenon that stains the next copy. There is also a problem of doing so.

In the heating roll fixing method, a peeling claw is provided on the fixing roll to prevent the transfer material, generally paper, from winding around the roll after passing through the fixing roll.
However, in recent years, as the speed of the copying machine has been increased, the stress applied to this portion has increased, and thus troubles such as defective peeling and image defects at the leading end of the transfer material due to the peeling claw when peeled have occurred. Further, there is a case where a copy image is further copied using a document as an original. When the copy image is put into an automatic document feeder of a copying machine, the copy image as the original is rubbed by a paper feed roller of the device, and the image is copied. Bleeding and dirt occur. Further, in the case of a two-sided document or a multicolor document, after the first copy image is fixed, the image surface is rubbed by the paper feed roller for the second copy, and the image is blurred or stained. Further, a plurality of originals stacked and temporarily stored in a copying machine are taken out one by one by a paper feed roller for a second copy. Rubs the image surface of the original, causing rubbing stains and bleeding on both surfaces, and as a result, lowering the image quality.

As a method for solving these problems, a method of grafting a polyolefin to a resin and making the resin compatible with the resin (Japanese Patent Application Laid-Open Nos. 60-457 and 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
No. 14508, JP-A-63-191817, etc.) are known. However, the above-mentioned method can improve the dispersibility of polyolefin and suppress the deterioration of powder fluidity, cohesiveness, and the like to some extent, but impair the originally required effect of improving the releasing ability.

On the other hand, there has been proposed a method of using a binder resin having a molecular weight of two peaks composed of a low molecular weight polymer component and a high molecular weight polymer component of a resin having the same composition ratio (Japanese Patent Application Laid-Open No. 56-56). -27156, etc.). in this way,
The low-molecular-weight polymer component in the binder resin is intended to lower the minimum fixing temperature, and the high-molecular-weight polymer component is intended to suppress the offset phenomenon.However, there is a case where each function adversely affects each other. The offset suppressing effect may be impaired by the influence of the molecular weight polymer component.
That is, although the offset phenomenon is suppressed to some extent by the high molecular weight polymer component, since the low molecular weight polymer component contained also exists on the toner surface, when applied to the heating roll fixing method, the offset phenomenon is large. The toner may adhere to the heating roll, which may also cause an offset phenomenon.

[0007]

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, an object of the present invention is to develop an electrostatic image with less power consumption, in other words, fixing at a lower temperature, good offset resistance, excellent powder fluidity, and no blocking phenomenon. To provide a toner for use. Another object of the present invention is to provide a toner for developing an electrostatic charge image having excellent rubbed image strength without being damaged by a peeling nail of a fixing roll portion. Another object of the present invention is to provide an image forming method using the above toner.

[0008]

The present inventors have conducted intensive studies and have found that a specific styrene-acrylic copolymer is used as a binder resin, and a styrene monomer and / or an unsaturated carboxylic acid is used as a lubricant. The present inventors have found that the above problems can be solved by adding a modified polyethylene-based wax having specific physical properties, which has been graft-modified with a monomer, and have completed the present invention.

The electrostatic image developing toner of the present invention contains a binder resin, a colorant and a lubricant, and the binder resin has a weight average molecular weight in the range of 1,000 to 50,000 and in the range of 100,000 to 1,000,000. And a styrene-acrylic copolymer having at least one molecular weight peak each, and an ethylene homopolymer obtained by polymerizing the lubricant in the presence of a metallocene-based catalyst, ethylene and ethylene having 3 to 3 carbon atoms. A styrene-based monomer and / or a polyethylene-based polymer selected from copolymers with α-olefins of No. 10
Alternatively, it is a modified polyethylene wax obtained by graft modification with an unsaturated carboxylic acid monomer and extracting 65% by weight or less of hexane.

In addition to the above, the binder resin of the present invention has a molecular weight distribution, Mw (weight average molecular weight) / Mn (number average molecular weight) in the range of 20 to 90, and further has a styrene-acrylic monomer copolymer. When the polymerization ratio is 60: 4
It is preferably in the range of 0 to 90:10.

In the present invention, the lubricant has a density of 0.95 g.
/ Cm ³ or more. In particular, a density of 0.95
g / cm ³ or more, viscosity average molecular weight 800 to 300
0, 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, a styrene monomer and / or an unsaturated carboxylic acid monomer Graft modified with 5 to 30 parts by weight, melt viscosity at 160 ° C. is 15 cps to 250 cps, and penetration is 2 dm.
It is preferably a graft-modified polyethylene wax having a molecular weight of m or less.

An image forming method according to the present invention comprises a latent image forming step of forming a latent image on a latent image carrier, a developing step of developing the latent image using a developer, and a step of transferring the developed toner image onto a transfer member. And a fixing step of heating and fixing the toner image on the transfer member.
A toner containing a toner for developing an electrostatic image according to any one of (1) to (3).

In this specification, the molecular weight distribution Mw / Mn of the polyethylene wax is determined by using GPC150C manufactured by Waters Co., at a temperature of 140 ° C. and a solvent o-
Dichlorobenzene was measured at a measurement flow rate of 1.0 ml / min at a concentration of 0.1% by weight, and the molecular weight was a value calculated using a viscosity formula of polyethylene. As a column, GMH manufactured by Tosoh Corporation was used. -HT (60cm) and GM
What connected H-HTL (60 cm) was used. The penetration is JIS K2207 and the density is JIS K676.
According to 0, the melt viscosity was measured by a Brookfields viscometer by heating and melting the sample at 160 ° C.

[0014]

Embodiments of the present invention will be described below in detail. The lubricant used in the present invention is obtained by converting a polyethylene polymer selected from an ethylene homopolymer and a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms with a styrene monomer and / or an unsaturated carboxylic acid monomer. Although it is obtained by graft modification, it is necessary that the ethylene homopolymer or copolymer used is obtained by polymerizing in the presence of a metallocene catalyst.

The metallocene catalyst can obtain a polymer having a narrow molecular weight distribution as compared with a conventional catalyst system. For this reason,
A method of degassing under vacuum at a temperature equal to or higher than the melting point, a method of dissolving in a solvent such as hexane-acetone to remove a low molecular weight part, dissolving the entire amount in a solvent, and then precipitating at a specific temperature to form a high molecular weight part By a method based on molecular weight distribution (Mw / Mn) control only by the removal method, it is not necessary to narrow the molecular weight distribution for the present invention, or even if it becomes necessary, this can be carried out efficiently. Also, unlike the molecular weight distribution control by the method as described above, since the molecular structure / molecular chain length can be controlled regularly from the time of wax polymerization, it is possible to synthesize a polyethylene wax having a higher density even in a low molecular weight region. . Further, from the advantages related to the molecular weight distribution control and the like as described above, the details of the modified polyethylene-based wax according to the present method are unknown, but not only can the defects of the extremely low molecular weight component possessed by ordinary lubricants be reduced, but also the desired Even in the viscosity average molecular weight range, there is an advantage that it is easier to control the wax so as to exhibit a desired melt viscosity while maintaining a balance with other physical properties of the wax, as compared with a usual method.

In the present invention, the metallocene-based catalyst can be used without any particular limitation.
For example, (A) IVb. Vb. Examples include a metallocene catalyst comprising a combination of a transition metal compound selected from the group consisting of Group VIb and (B) a cocatalyst. As such a compound of a transition metal, a compound represented by the following general formula (1) ML _x ... (1) can be exemplified.

In the formula, M represents a transition metal atom selected from group IV transition metal atoms, and examples thereof include zirconium, titanium, and hafnium. x is the valence of the transition metal;
Indicates the number of L represents a ligand or a group coordinated to a transition metal, and at least one L is a ligand having a cyclopentadienyl skeleton such as cyclopentadienyl or indenyl; A hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group, SO ₃ R ¹ (where R ¹ is a carbon group having 1 to 8 carbon atoms which may have a substituent such as halogen); A hydrogen group), 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, two of the ligands having a cyclopentadienyl skeleton are ethylene, It may be bonded via an alkylene group such as propylene, a substituted alkylene group such as isopropylidene or diphenylmethylene, a silylene group, or a substituted silylene group such as a dimethylsilylene group or 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 ethoxycyclolide, bis (n-butylcyclopentadienyl) zirconium butoxycyclolide, bis (n-butylcyclopentadienyl) zirconium diethoxide,
Bis (n-butylcyclopentadienyl) zirconium methyl chloride, bis (n-butylcyclopentadienyl) zirconium dimethyl, bis (n-butylcyclopentadienyl) zirconium benzyl chloride, bis (n-butylcyclopentadienyl) ) Dibenzyl zirconium, bis (n-butylcyclopentadienyl) zirconium phenyl chloride, bis (n-butylcyclopentadienyl) zirconium hydride chloride,

Ethylene bis (indenyl) dimethyl zirconium, ethylene bis (indenyl) diethyl zirconium, ethylene bis (indenyl) diphenyl zirconium, ethylene bis (indenyl) methyl zirconium monochloride, ethylene bis (indenyl) ethyl zirconium monochloride, ethylene bis ( Indenyl)
Methyl zirconium monobromide, ethylene bis (indenyl) zirconium dichloride, ethylene bis (indenyl) zirconium dibromide, ethylene bis ｛1-
(4,5,6,7-tetrahydroindenyl)｝ dimethylzirconium, ethylenebis ｛1- (4,5,6,7
-Tetrahydroindenyl)｝ methylzirconium monochloride, ethylenebis ｛1- (4,5,6,7-tetrahydroindenyl)｝ zirconium dichloride, ethylenebis ｛1- (4,5,6,7-tetrahydroindenyl) )｝ Zirconium dibromide, ethylenebis ｛1-
(4-methylindenyl) zirconium dichloride,
Ethylene bis {1- (5-methylindenyl)} zirconium dichloride, ethylene bis {1- (6-methylindenyl)} zirconium dichloride, ethylene bis {1- (7-methylindenyl)} zirconium dichloride, ethylene bis {1- (5-methoxyindenyl)} zirconium dichloride, ethylenebis {1-
(2,3-dimethylindenyl) {zirconium dichloride, ethylene bis} 1- (4,7-dimethylindenyl)} zirconium dichloride, ethylene bis {1-
(4,7-dimethoxyindenyl) zirconium dichloride,

Isopropylidene (cyclopentadienyl-fluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-2,7-di-t-butylfluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-methylcyclo) Pentadienyl) zirconium dichloride, dimethylsilylenebis (cyclopentadienyl) zirconium dichloride,
Dimethylsilylenebis (methylcyclopentadienyl)
Zirconium dichloride, dimethylsilylene bis (dimethylcyclopentadienyl) zirconium dichloride,
Examples include dimethylsilylenebis (trimethylcyclopentadienyl) zirconium dichloride, dimethylsilylenebis (indenyl) zirconium dichloride, diphenylsilylenebis (indenyl) zirconium dichloride, and the like. In the above example, disubstituted cyclopentadienyl ring includes 1,2- and 1,3-substituted, and tri-substituted includes 1,2,3- and 1,2,4-substituted. Including. 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 cocatalyst (B), conventionally known ones can be used without any 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 exemplified. As the aluminoxane (B-1), specifically, the following general formula (2) or (3)

Embedded image (Wherein, R ² represents a hydrocarbon group and m represents an integer of 2 or more). In the above aluminoxane, R ² represents a methyl group, an ethyl group, a propyl group, an n-butyl group, is
Examples thereof include an o-butyl group, a phenyl group, a phenylmethyl group and the like, and preferred are a methyl group, an ethyl group, and an iso-butyl group. m is an integer of 2 or more, preferably 3 to 5
0, particularly preferably an integer of 3 to 40.

The method for obtaining aluminoxane includes, for example, (1) a method for suspending a compound containing adsorbed water or a salt containing water of crystallization, for example, a hydrocarbon catalyst such as hydrated magnesium or copper sulfate. A method in which an organic aluminum compound such as a trialkylaluminum is reacted with the suspension to recover as a hydrocarbon solution; (2) water or ice is directly applied to the organic aluminum compound such as a trialkylaluminum in a catalyst such as benzene or toluene; There is a method of recovering a hydrocarbon solution by applying steam. Examples of the organoaluminum compound used include trimethylaluminum, triethylaluminum, tripropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-sec-butylaluminum, tri-tert-butylaluminum, triisopentylaluminum and the like. Is done.

The compound (B-2) which reacts with the transition metal compound (A) to form an ionic complex is, for example, a compound comprising a cation and an anion having a plurality of groups bonded to an element, especially Preference is given to coordination complex compounds. Such compounds include trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, triphenylammonium tetraphenylborate (n-
Butyl) ammonium, trimethylammonium tetra (pentafluorophenyl) borate, triethylammonium tetra (pentafluorophenyl) borate, tri (n-butyl) ammonium tetra (pentafluorophenyl) borate, triethylammonium hexafluoroarsenate, ferrocenium tetraphenylborate , Trityl tetraphenylborate, tetra (pentafluorophenyl)
Ferrocenium borate, methyl ferrocenium tetra (pentafluorophenyl) borate, 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 trifluorometasulfonic acid, tetra (pentafluorophenyl) borate (N-benzyl-2)
-Cyanopyridium), tetra (pentafluorophenyl) borate (N-benzyl-3-cyanopyridium), tetra (pentafluorophenyl) borate (N-benzyl-)
4-cyanopyridium), tetra (pentafluorophenyl) borate (N-methyl-2-cyanopyridium), tetra (pentafluorophenyl) borate (N-methyl-3)
-Cyanopyridium), tetra (pentafluorophenyl) borate (N-methyl-4-cyanopyridium), trimethylanilinium tetra (pentafluorophenyl) borate, trimethyltetra (pentafluorophenyl) borate (m-trifluoromethyl) Phenyl) ammonium,
Benzylpyridium tetra (pentafluorophenyl) borate; and the like.

An organoaluminum compound (C) may be used together with the cocatalyst (B), if necessary.
As such an organoaluminum compound of (C),
The compound represented by the following general formula (4) can be exemplified. R ³ _n AlX _3-n (4) (wherein, R ³ represents a hydrocarbon having 1 to 12 carbons, X represents a halogen atom or a hydrogen atom, and n is an integer of 1 to 3) Means.)

In the above formula (4), R ³ represents a hydrocarbon group having 1 to 12 carbon atoms, for example, an alkyl group, a cycloalkyl group or an aryl group. -Propyl group, iso-propyl group,
iso-butyl, pentyl, hexyl, octyl, cyclopentyl, cyclohexyl, phenyl, tolyl and the like. Examples of such organoaluminum compounds include trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, tri2-ethylhexylaluminum; alkenylaluminums such as isoprenylaluminum; dimethylaluminum Dialkylaluminum halides such as chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, dimethylaluminum bromide; methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide Alkylaluminum sesqui halides; methyl aluminum dichloride, ethyl aluminum dichloride, alkyl aluminum dihalides such as isopropyl aluminum dichloride, ethyl aluminum dibromide; alkylaluminum hydrides such as diethylaluminum hydride, diisobutylaluminum hydride;
And the like.

In the present invention, a metallocene catalyst comprising the above-mentioned transition metal compound (A), co-catalyst (B) and, if necessary, organoaluminum compound (C) represented by the above-mentioned general formula (4) is used. You. The polymerization reaction performed using these metallocene catalysts is carried out in a hydrocarbon medium. Specific examples of the hydrocarbon medium include aliphatic hydrocarbons such as butane, isobutane, pentane, hexane, octane, decane, dodecane, hexadecane, and octadecane; and oils such as cyclopentane, methylcyclopentane, cyclohexane, and cyclooctane. Examples thereof include aromatic hydrocarbons, aromatic hydrocarbons such as benzene, toluene, and xylene, and petroleum fractions such as gasoline, kerosene, and light oil. In addition, olefins as raw materials also serve as hydrocarbon media. Among these hydrocarbon media, aromatic hydrocarbons are preferred.

When an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms is produced, the ratio of the transition metal compound used in the metallocene catalyst in the liquid phase polymerization method is as follows: The concentration of the transition metal atom in the polymerization reaction system is usually in the range of 10 ^-8 to 10 ^-2 gram atom / liter, preferably 10 ^-7 to 10 ^-3 gram atom / liter. The ratio of aluminoxane used 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. And the ratio of aluminum atom to transition metal atom in the polymerization reaction system is usually 4 to 1
0 ⁷ , preferably in the range of 10 to 10 ⁶ .

In the above polymerization, the molecular weight of the ethylene homopolymer or copolymer can be adjusted by controlling the hydrogen and / or the polymerization temperature. The temperature at the time of the polymerization reaction is usually at least 20 ° C, particularly preferably 50 ° C to 2 ° C.
It is in the range of 30 ° C. The amount of hydrogen supplied to the polymerization reaction is usually in the range of 0.01 to 4, preferably 0.05 to 2, as a molar ratio of hydrogen to ethylene.

In the present invention, a homopolymer of ethylene or a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms obtained by polymerization in the presence of the above-mentioned metallocene catalyst can be obtained by heating the copolymer in decalin at 135 ° C. Those having a measured intrinsic viscosity [η] of preferably 0.4 dl / g or less, particularly preferably in the range of 0.005 to 0.35 dl / g, are preferably used. 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%.

Further, the ethylene homopolymer or ethylene copolymer thus obtained has a viscosity average molecular weight of 800 to 3000, a density of 0.95 g / c.
m ³ or more, and the penetration is 2 dm or less, further 1 dm
m is more preferable. Polyethylene in this range has a self-lubricating property due to its high density and linearity of molecules, thereby reducing the damage due to abrasion of the fixed image surface,
It is possible to prevent rubbing stains, bleeding, and the like from occurring 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 lubricating effect is sufficiently exhibited. In addition, the molecular weight distribution (Mw / Mw / Mn / g) of the homopolymer or ethylene copolymer of the present ethylene (hereinafter simply referred to as polyethylene wax) determined by gel permeation chromatography (hereinafter simply referred to as GPC).
Mn) is usually preferably from 1.05 to 1.8, more preferably from 1.05 to 1.5, even more preferably from 1.05 to 1.3.

When the molecular weight distribution Mw / Mn is in this range,
Within the above-mentioned range of the viscosity average molecular weight, it is possible to reduce a component having a high molecular weight and a component having a low molecular weight in the polyethylene wax. 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

This also has a significant effect on the melting behavior of the polyethylene wax itself. The wax is required to maintain a completely solid state in a normal state, and to completely dissolve at a temperature close to the set temperature of the fixing roll during an extremely short passage time when passing through the fixing roll. ing. When the molecular weight distribution is controlled within the above range, the melting temperature range which the wax has until the melting is completed can be narrowed as compared with the usual case. As a result, the amount of wax contributing to the release (the amount of wax dissolved at the set temperature of the fixing roll) increases, and the efficiency is improved from the viewpoint of the manifestation effect. About the polyethylene wax produced by the above method, further deaeration under vacuum at a temperature equal to or higher than the melting point, a method of removing the low molecular weight part by dissolving in a solvent such as hexane / acetone, or after dissolving the entire amount in the solvent, A technique of removing the high molecular weight part by precipitating at a specific temperature may be used in combination.

The polyethylene polymer is graft-modified with a styrene monomer and / or an unsaturated carboxylic acid monomer, but the styrene monomer and the unsaturated carboxylic acid monomer are not particularly limited. Styrene-based monomers 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-n-butylstyrene, 4-sec-butylstyrene, 4-tert-butylstyrene, 4-hexylstyrene, 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 and the like.

Examples of unsaturated carboxylic acid monomers 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, diethylene glycol ethoxy acrylate, Acrylates such as 2,2,2-trifluoroethyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate;
Propyl methacrylate, isopropyl methacrylate, 2-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, hexyl methacrylate, decyl methacrylate, phenyl methacrylate, 2-methacrylic acid
Chlorohexyl, diethylaminoethyl methacrylate,
2-hexylethyl methacrylate, methacrylic acid 2,
Methacrylic esters such as 2,2-trifluoroethyl, and other maleic esters such as ethyl maleate, propyl maleate, butyl maleate, diethyl maleate, dipropyl maleate, dibutyl maleate, and ethyl fumarate And fumaric acid esters such as butyl fumarate and dibutyl fumarate; and itaconic acid esters such as ethyl itaconate, diethyl itaconate and butyl itaconate.

Further, the above-mentioned polyethylene wax is
When the graft modification ratio of the styrene monomer or the unsaturated carboxylic acid monomer is 100 parts by weight in total,
It is preferably from 5 to 30 parts by weight. If the graft-modified component is controlled in this range, adverse effects on powder fluidity, blocking properties, caking resistance, and the like due to large domains, a releasing effect due to too much dispersion of the lubricant in the toner, and rubbing-resistant images Good performance can be exhibited without a decrease in strength or the like.

As a method for modifying the above-mentioned monomer into a polyethylene polymer, various known methods can be used. For example, there is a method in which a polyethylene-based polymer and a styrene-based monomer or an acrylic-based monomer are heated and melt-mixed in the presence of a radical initiator to cause a reaction, and the like. In this case, the reaction temperature is preferably 125 to 325 ° C., and the radical initiator used is a peroxide such as benzoyl peroxide, lauroyl peroxide, dicumyl peroxide, di-t-butyl peroxide, or azobisisobutyric acid. Examples include azo compounds such as lonitrile.

It is necessary that the hexane extraction amount of the modified polyethylene wax be 65% or less. Within this range, the wax itself has high blocking resistance, and when added to the toner, exhibits good fluidity without causing aggregation or the like even under stress conditions such as temperature or humidity than usual. It is possible. The amount of hexane extraction is a value obtained by placing 2 g of wax in a cylindrical filter paper and performing boiling point extraction with normal hexane for 5 hours using a Soxhlet apparatus, and then calculating the amount of the wax remaining on the filter paper in% by weight. .

The melt viscosity of the modified polyethylene wax is 15 to 250 cps at 160 ° C.
Further, the penetration is preferably 2 dmm or less, more preferably 1 dmm or less. Within 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, and image peeling by the peeling nail, defective release, and occurrence of peeling nail scratches due to excessive stress at the time of releasing. It is possible to hold down.

In the toner of the present invention, the amount of the modified polyethylene wax to be added to the toner is suitably 2 to 30% by weight of the toner weight, and more preferably 4 to 10% by weight.

On the other hand, the binder resin used in the present invention is:
It is a styrene-acrylic copolymer having at least one molecular weight peak in the weight average molecular weight of 1,000 to 50,000 and 100,000 to 1,000,000, respectively. Further, its molecular weight distribution, Mw (weight average molecular weight)
/ Mn (number average molecular weight) is preferably in the range of 20 to 90, and the copolymerization ratio of styrene-acrylic monomer is preferably in the range of 60:40 to 90:10.

First, in the case of the binder resin (1), the ranges of the weight average molecular weight and the number average molecular weight are preferably as follows. High molecular weight component: Mw = 1 × 10 ⁵ -5 × 10 ⁵ Mn = 1 × 10 ⁵ -5 × 10 ⁶ Low molecular weight component: Mw = 2 × 10 ³ -5 × 10 ⁴ Mn = 2 × 10 ^{3 -3} × 10 ⁴ The molecular weight distribution M of the styrene-acrylic copolymer
w / Mn needs to be in the range of 20 to 90, and particularly preferably in the range of 40 to 70. The measurement of the molecular weight and the molecular weight distribution of the binder resin is performed by using HL
C-802A (Toyoda) column GMH6x
After preparing a calibration curve using 10 kinds of TSK standard polystyrene, the binder resin was changed to tetrahydrofuran (THF).
And measured by HLC-802A. When the above-mentioned binder resin and the modified polyethylene wax are used in combination, the details are unknown, but the modified polyethylene wax is a rheologically similar low molecular weight resin component as compared with the resin component on the high molecular weight side. As a result, when the toner is melted, it does not hinder the low-temperature fixability of the resin component on the low molecular weight side, and after passing through the heat fixing roll, the resin on the toner surface (including inside) has a low molecular weight. By suppressing the adverse effect of the components on the releasability, it becomes possible to exhibit the offset resistance of the resin component on the high molecular weight side.

Further, the styrene-acrylic monomer copolymerization ratio of the binder resin is in the range of 60:40 to 90:10, and more preferably in the range of 70:30 to 85:15. When the proportion of styrene in the copolymer is less than 60% by weight, the Tg of the entire resin is reduced, and the blocking property and the like are significantly reduced. If the styrene content is 90% by weight or more, viscoelasticity cannot be obtained so that the toner can exhibit desired fixability to paper or the like.

The monomers to be applied to the above-mentioned styrene-acrylic copolymer include styrene-based monomers such as styrene, α-methylstyrene, chlorostyrene and vinylstyrene, and the like.
Use α-methylene aliphatic monocarboxylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, etc. However, the present invention is not limited to these.

Further, the toner for developing an electrostatic image of the present invention comprises:
Contains a colorant as one of the main components, as the colorant component, carbon black, dyes and pigments,
For example, nigrosine dye, aniline blue, calcoil blue, chrome yellow, 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. I. Pigment Red 122, C.I. I. Pigment Red 57:
1, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 12, C.I. I. Pigment Blue 1
5: 1, C.I. I. Pigment Blue 15: 3 and the like can be exemplified as typical examples. The colorant is not limited to those exemplified above, and the compounding amount thereof is 1 to 20 parts by weight, more preferably 3 to 20 parts by weight, based on the toner.
To 12 parts by weight.

The toner may contain a known additive such as a charge control agent, if necessary. Further, other inorganic compound fine particles such as a fluidity improver including colloidal silica fine particles may be externally added.

Next, an image forming method of the present invention using the above toner will be described. The image forming method of the present invention includes a latent image forming step of forming a latent image on an electrostatic latent image carrier,
A developing step of developing the latent image using a developer; a transferring step of transferring the developed toner image onto a transfer body; and a fixing step of heating and fixing the toner image on the transfer body. In particular,
An electrostatic latent image is formed on an electrostatic latent image carrier such as a photoreceptor or an electrostatic recording medium by electrophotography or by a needle-like electrode. As the electrostatic latent image carrier, a Se-based photoreceptor, an organic-based photoreceptor, an amorphous silicon-based photoreceptor, a surface of which is coated as necessary, or a dielectric such as polyethylene terephthalate Conventionally known ones such as an electrostatic recording medium having the following can be used. The formed electrostatic latent image is then developed using the toner described above, and any one of a one-component developing method and a two-component developing method can be used. When used as a two-component developer, known carriers such as ferrite, iron oxide powder, magnetite, a resin-coated carrier obtained by coating these with a resin, and a magnetic powder-dispersed carrier can be used. The toner image formed by the development is then transferred onto a transfer member. The transferred toner image is heated and fixed by pressing a heating roll having an elastic layer on the surface thereof onto the transfer body. The toner remaining on the electrostatic latent image carrier is then cleaned by known cleaning means.

FIG. 1 is a side sectional view showing a schematic configuration of an example of a fixing device used in the present invention. The main part of the fixing device includes a heating roll 1 and a pressure roll 2, and the transfer member carrying the toner image 8 passes between the two rolls. The heating roll includes a heating source 7 therein, and has a structure in which a metal core 3 is covered with an elastic layer 4. The pressure roll has a structure in which a heating source 7 is provided inside the pressure roll and an elastic layer 6 is provided on the metal core 5. Reference numeral 9 denotes an isolation claw.

In the present invention, as the constituent material of the elastic layer on the surface of the heating roll, a fluoroelastomer and a silicone elastomer are preferable. Specifically, as the fluoroelastomer, a copolymer of vinylidene fluoride and hexafluoropropylene is used as a viton (vito).
n) A, a terpolymer of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene, viton B, viton GH, viton EGO
C, Viton E430 (above, manufactured by EI DuPont), Fluorel 2170, Fluorel 2174, Fluoryl 2176, Fluoryl 217
7, Fluorel IVS76 (all manufactured by 3M) and the like. Examples of the silicone elastomer include a high temperature curing type (HTV), a room temperature curing type (RTV), and a low temperature curing type (LTV). Still other constituent materials include a mixture of a fluoroelastomer based on vinylidene fluoride and another material, for example, a mixture of tetrafluoroethylene, silicone rubber, fluorosilicone rubber and the like.

When a material having relatively high hardness such as the aforementioned viton is used for the roll surface portion, a second elastic layer is provided between the surface layer portion and the substrate roll in order to further impart sufficient elasticity to the surface layer. May be provided, as a constituent material of the second elastic layer, fluorosilicone elastomer, silicone elastomer, various other silicone rubber,
Examples include various organic rubbers such as fluorocarbon elastomers and ethylene / propylene / diene rubbers. The second elastic layer and the surface elastic layer may be appropriately added with a metal-containing filler in order to impart high heat conductivity.Specifically, copper, tin, silver, zinc, aluminum,
Examples include metals such as iron, molybdenum, platinum, gold, beryllium, nickel, chromium, iridium, ruthenium, tungsten, and vanadium, alloys of these metals, metal oxides and metal salts.

When the toner for electrostatic development containing the binder resin and the modified polyethylene wax as essential components is used for the fixing device as described above, details of the modified polyethylene wax are unknown. Evenly dispersed on the toner surface, the wax does not have a very high molecular weight component that seems to viscoelastically inhibit the stress reduction effect at the time of release, and also does not damage the roll surface by controlling each physical property value, Details are unknown, but by relaxing stress applied to the elastic layer on the roll surface (non-image area of the transfer body passing through the fixing roll, etc.), it is possible to extend the life of the roll and achieve high mold release. Becomes possible. Furthermore, by controlling the components compatible with the binder resin possessed by the modified polyethylene wax, the powder fluidity of the toner can be improved without impairing the rubbed image strength and the peeling nail scratch suppression effect possessed by the modified polyethylene wax itself. In addition, the blocking property and the anti-cakeing property can be reduced.

[0051]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited to these Examples. In the following description, “parts” means “parts by weight”. (Example of Production of Polyethylene Polymer Using Metallocene Catalyst) Production Example A Using a continuous polymerization reactor, purified hexane was supplied at 200 L / h.
r, 0.4 mol / hr of methylaluminoxane (manufactured by Tosoh Akzo) in terms of aluminum atom, 0.2 mol / hr of trimethylaluminum, and zirconium atom of bis (n-butylcyclopentadienyl) zirconium dichloride continuously fed at a rate of 2 mmol / hr in terms of hydrogen to ethylene ratio in the gas phase in the polymerization reactor _{(H 2 / C 2 H 4} ) is 0.40, total pressure 30kg / cm
Ethylene and hydrogen were continuously supplied so as to obtain ² G, and polymerization was carried out under the conditions of a polymerization temperature of 140 ° C., normal pressure, a residence time of 0.5 hour, and a polymer concentration of 90 g / L. 5 L of methanol was added to 1 L of the obtained polymer solution,
After precipitating the polymer, the polymer was recovered by filtration and dried to obtain a polyethylene wax having the following physical properties. [Η] 0.08 dl / g Molecular weight distribution Mw / Mn 1.3 Viscosity average molecular weight 1130 Density 0.96 g / cm ³ Melt viscosity at 160 ° C. 12.0 cps

Production Example B In the same manner as in Production Example A, except that the ratio of hydrogen to ethylene (H ₂ / C ₂ H ₄ ) in the gas phase in the polymerization vessel was changed to 0.50 in the polymerization reaction of Production Example A, A polymerization reaction was performed. The physical properties of the obtained polyethylene wax were as follows. [Η] 0.06 dl / g Molecular weight distribution Mw / Mn 1.2 Viscosity average molecular weight 890 Density 0.96 g / cm ³ Melt viscosity at 160 ° C. 7.7 cps

Production Example C 1200 g of the polyethylene wax obtained in Production Example A was dissolved in 2000 ml of hexane at 60 ° C. and left at 50 ° C. for 1 hour. After the precipitate was removed by filtration, the filtrate was cooled to 25 ° C. The obtained precipitate was filtered and then dried. The physical properties of the obtained polyethylene wax were as follows. [Η] 0.06 dl / g Molecular weight distribution Mw / Mn 1.12 Viscosity average molecular weight 1400 Density 0.96 g / cm ³ Melt viscosity at 160 ° C. 12.0 cps

Production Example D A polymerization reaction was carried out in the same manner as in Production Example A, except that the polymerization temperature was changed to 145 ° C. The physical properties of the obtained polyethylene wax were as follows. [Η] 0.06 dl / g Molecular weight distribution Mw / Mn 1.37 Viscosity average molecular weight 1070 Density 0.96 g / cm ³ Melt viscosity at 160 ° C. 10.0 cps

(Production Examples of Various Graft-Modified Polyethylene Waxes) Production Example 1 The polyethylene wax obtained in the above Production Example A ([η]: 0.08 dl / g, molecular weight distribution Mw / Mn:
1.3, viscosity average molecular weight: 1130, density: 0.96 /
cm ³ , melt viscosity at 160 ° C .: 12.0 cps) 10
00g was melted at 160 ° C, 250 g of styrene,
21 g of tert-butyl peroxide was separately added dropwise from a conduit over 4 hours. After the dropping is completed,
After continuing the reaction for 30 hours, 30 mm
Degassed under Hg vacuum for 1 hour, modified polyethylene wax (penetration: 1 dmm or less, melt viscosity at 160 ° C .: 2)
8.5 cps, hexane extraction: 62.5%).

Production Example 2 The polyethylene wax obtained in Production Example B above ([η]: 0.06 dl / g, molecular weight distribution Mw / Mn:
1.2, viscosity average molecular weight: 890, density: 0.96 g /
Melt viscosity at 160 ° C., cm ³ : 7.7 cps) 100
A modified polyethylene wax (penetration: 1 dmm or less, melt viscosity at 160 ° C .: 17.0 cps, hexane extraction: 63.0) was used in the same manner as in Production Example 1 except that 0 g was used.
%). Production Example 3 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.
Modified polyethylene wax in the same manner as described above (penetration: 1d
mm, melt viscosity at 160 ° C .: 20.5 cps, hexane extraction: 58.5%). Production Example 4 Modified polyethylene wax (penetration: 1) except that a mixture of 125 g of styrene and 125 g of butyl methacrylate was used instead of 250 g of styrene.
dmm or less, melt viscosity at 160 ° C .: 20.0 cps,
Hexane extraction: 55.0%). Production Example 5 Modified polyethylene wax (penetration: 1 dmm or less, melt viscosity at 160 ° C .: 2) in the same manner as in Production Example 1 except that 1000 g of the polyethylene wax of Production Example C was used.
3.7 cps, hexane extraction: 61.5%).

Production Example 6 Polyethylene wax polymerized using a Ziegler catalyst (viscosity average molecular weight: 900, molecular weight distribution Mw / Mn: 2.20, density: 0.95 g / cm ³ , 1)
Modified polyethylene wax (penetration: 1 dmm or less, melt viscosity at 160 ° C: 22.0 cps, hexane extraction amount) in the same manner as in Production Example 1 except that 1000 g of a melt viscosity at 60 ° C: 10.0 cps was used. : 70.0%). Production Example 7 Polyethylene wax polymerized using a Ziegler catalyst (viscosity average molecular weight: 1070, molecular weight distribution Mw / M)
n: 1.30, density: 0.96 g / cm ³ , melt viscosity at 160 ° C .: 12.0 cps), except that 1000 g, 20 g of styrene and 1.7 g of di-t-butyl peroxide were used. A modified polyethylene wax (penetration: 1 dmm or less, melt viscosity at 160 ° C .: 12.0 cps, hexane extraction: 58.0%) was obtained in the same manner as in Example 1. Production Example 8 Production Example 7 was repeated except that a mixture of 125 g of styrene and 540 g of dibutyl fumarate was used instead of 250 g of styrene.
Modified polyethylene wax (penetration: 2d)
mm, melt viscosity at 160 ° C .: 130.0 cps, hexane extraction: 65.0%).

Production Example 9 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) 10
A modified polypropylene wax (penetration: 1 dmm, melt viscosity at 160 ° C: 250.0 cps, hexane extraction: 75.
0%). Production Example 10 Modified polyethylene wax (penetration: 1 dmm, melt viscosity at 160 ° C .: 22.0) in the same manner as in Production Example 1 except that 1000 g of the polyethylene wax of Production Example D was used.
cps, hexane extraction: 67.0%). Production Example 11 Production Example 1 was repeated except that a mixture of 125 g of styrene and 125 g of dibutyl fumarate was used instead of 250 g of styrene.
Modified polyethylene wax (penetration: 1)
dmm, melt viscosity at 160 ° C .: 16.0 cps, hexane extraction amount: 71.5%).

Next, examples and comparative examples of the present invention will be described. Example 1 (Preparation of Toner) Low Molecular Weight Polymer Component Styrene-butyl methacrylate copolymer [90/10] 60 parts Mw = 7.0 × 10 ³ , Mn = 4.0 × 10 ³ High molecular weight polymer component Styrene-butyl methacrylate copolymer [60/40] 40 parts Mw = 7.0 × 10 ⁵ , Mn = 2.2 × 10 ⁵ Binder resin obtained by mixing the above components 100 parts Mw / Mn = 69 .2 Styrene-butyl methacrylate ratio = 78: 22 Carbon black (R330: manufactured by Cabot) 10 parts Charge control agent (P-51: manufactured by Orient Chemical Industries) 2 parts Modified polyethylene wax shown in Production Example 1 5 parts The components were melt-kneaded with a Banbury mixer, cooled, finely pulverized by a jet mill, and classified by a classifier to obtain toner particles having an average particle diameter of 10 μm. The average primary particle size is 0.015 μm with respect to 100 parts of the toner particles.
Was added and dispersed and mixed with a Henschel mixer to prepare a toner. (Preparation of Carrier) An 85 μm ferrite core was obtained by coating a silicone resin. (Preparation of Developer) A developer composition was prepared by mixing 3 parts of the toner and 97 parts of the carrier.

Example 2 A developer composition was obtained in the same manner as in Example 1 except that the modified polyethylene wax shown in Production Example 2 was used as a lubricant. Example 3 A developer composition was obtained in the same manner as in Example 1, except that the modified polyethylene wax shown in Production Example 3 was used as a lubricant. Example 4 A developer composition was obtained in the same manner as in Example 1, except that the modified polyethylene wax shown in Production Example 4 was used as a lubricant. Example 5 A developer composition was obtained in the same manner as in Example 1, except that the modified polyethylene wax shown in Production Example 5 was used as a lubricant.

Example 6 A developer composition was obtained in the same manner as in Example 1 except that the following binder resin was used. Low molecular weight polymer component Styrene-butyl acrylate copolymer [90/10] 70 parts Mw = 7.6 × 10 ³ , Mn = 4.5 × 10 ³ High molecular weight polymer component Styrene-butyl acrylate copolymer [70/30] 30 parts Mw = 7.3 × 10 ⁵ , Mn = 3.8 × 10 ⁵ Binder resin obtained by mixing the above components 100 parts Mw / Mn = 51.6 Styrene-butyl acrylate ratio = 84: 16 Example 7 A developer composition was obtained in the same manner as in Example 6, except that the modified polyethylene wax shown in Production Example 3 was used as a lubricant.

Example 8 A developer composition was obtained in the same manner as in Example 2 except that the following binder resin was used. Low molecular weight polymer component Styrene-methyl acrylate copolymer [85/15] 60 parts Mw = 6.2 × 10 ³ , Mn = 3.8 × 10 ³ High molecular weight polymer component Styrene-methyl acrylate copolymer [75/25] 40 parts Mw = 3.6 × 10 ⁵ , Mn = 2.1 × 10 ⁵ Binder resin obtained by mixing the above components 100 parts Mw / Mn = 58.7 Styrene-methyl acrylate ratio = 81: 19 Example 9 A developer composition was obtained in the same manner as in Example 8, except that the modified polyethylene wax shown in Production Example 4 was used as a lubricant.

Comparative Example 1 As a lubricant, polyethylene wax polymerized using a Ziegler-type catalyst (viscosity average molecular weight: 2000, molecular weight distribution Mw / Mn: 2.60, density: 0.97 g / cm ³ ,
A developer composition was obtained in the same manner as in Example 1 except that the melt viscosity at 160 ° C .: 85.0 cps, and the amount of hexane extracted was 45.0%). Comparative Example 2 As a lubricant, a polypropylene wax (viscosity average molecular weight: 3000, molecular weight distribution Mw / Mn: 2.80, density: 0.89 g / cm ³ , melt viscosity at 160 ° C .: 7)
A developer composition was obtained in the same manner as in Example 1, except that 0.0 cps and a hexane extraction amount of 48.0%) were used. Comparative Example 3 A developer composition was obtained in the same manner as in Comparative Example 1, except that the modified polyethylene wax shown in Production Example 6 was used as a lubricant. Comparative Example 4 A developer composition was obtained in the same manner as in Comparative Example 1, except that the modified polyethylene wax shown in Production Example 7 was used as a lubricant. Comparative Example 5 A developer composition was obtained in the same manner as in Comparative Example 1, except that the modified polyethylene wax shown in Production Example 8 was used as a lubricant.

Comparative Example 6 A developer composition was obtained in the same manner as in Comparative Example 1, except that the modified polypropylene wax shown in Production Example 9 was used as a lubricant. Comparative Example 7 A developer composition was obtained in the same manner as in Example 1, except that a styrene-butyl methacrylate copolymer having a peak of one molecular weight and the following molecular weight was used as a binder resin. Mw = 1.9 × 10 ⁵ , Mn = 3.9 × 10 ³ Mw / Mn = 48.71 Styrene-butyl methacrylate ratio = 76: 24 Comparative Example 8 Except that the lubricant of Production Example 6 was used. In the same manner as in Comparative Example 7, a developer composition was obtained. Comparative Example 9 A developer composition was obtained in the same manner as in Example 1, except that a styrene-butyl acrylate copolymer having one molecular peak and the following molecular weight was used as the binder resin. Mw = 1.4 × 10 ⁵ , Mn = 8.4 × 10 ³ Mw / Mn = 16.67 Styrene-butyl acrylate ratio = 68: 32 Comparative Example 10 Except that the one of Production Example 6 was used as a lubricant. In the same manner as in Comparative Example 9, a developer composition was obtained.

Comparative Example 11 A developer composition was prepared in the same manner as in Example 1 except that a styrene-butyl acrylate copolymer having a peak of one molecular weight and the following molecular weight was used as a binder resin. Obtained. Mw = 1.9 × 10 ⁵ , Mn = 1.4 × 10 ³ Mw / Mn = 135.72 Styrene-butyl acrylate ratio = 84: 16 Comparative Example 12 Except that the thing of Production Example 6 was used as a lubricant. Comparative Example 11
In the same manner as in the above, a developer composition was obtained. Comparative Example 13 A developer composition was obtained in the same manner as in Example 1, except that a styrene-methyl acrylate copolymer having a peak of one molecular weight and the following molecular weight was used as a binder resin. Mw = 2.1 × 10 ⁵ , Mn = 3.4 × 10 ³ Mw / Mn = 61.76 Styrene-methyl acrylate ratio = 98: 2 Comparative Example 14 Except that the one of Production Example 6 was used as a lubricant, Comparative Example 13
In the same manner as in the above, a developer composition was obtained.

Comparative Example 15 A developer composition was prepared in the same manner as in Example 1 except that a styrene-methyl acrylate copolymer having a peak of one molecular weight and the following molecular weight was used as a binder resin. Obtained. Mw = 1.1 × 10 ⁵ , Mn = 1.6 × 10 ³ Mw / Mn = 68.75 Styrene-methyl acrylate ratio = 50: 50 Comparative Example 16 Except that the one of Production Example 6 was used as a lubricant, Comparative Example 15
In the same manner as in the above, a developer composition was obtained. Comparative Example 17 A developer composition was obtained in the same manner as in Example 1, except that the modified polyethylene wax shown in Production Example 10 was used as a lubricant. Comparative Example 18 A developer composition was obtained in the same manner as in Example 1, except that the modified polyethylene wax shown in Production Example 11 was used as a lubricant.

Test methods and evaluation criteria performed using the developer compositions of Examples 1 to 9 and Comparative Examples 1 to 18 are as follows. (1) Offset temperature Measured using an A-color (manufactured by Fuji Xerox) modified fixing device. Heat roll temperature from 160 ° C to 22
The temperature was raised to 0 ° C. in increments of 5 ° C., and the temperature at which offset occurred was visually checked. (Note that no occurrence means that no occurrence of offset is observed at 220 ° C.) (2) Peeling nail flaw disappearance temperature Measured using an A-color (manufactured by Fuji Xerox) fixing device. This indicates the heat roll temperature at which the peeling nail scratches generated in the solid black image at the leading end of the image reach a level that does not pose a problem in practical use. (It should be noted that "not generated" means that no peeled nail scratches are generated even at the measurement lower limit temperature of 120 ° C.)

(3) Peeling maintainability Measured using an A-color (manufactured by Fuji Xerox) fixing device. An unfixed solid image of 5 cm × 10 cm was repeatedly subjected to a fixing test at 160 ° C.
The releasability (winding resistance) after fixing 0 sheets was evaluated. G1: There is no winding or offset around the fixing roller even after fixing 10000 sheets, and there is no problem in the releasability. G2: A very slight offset phenomenon was observed from about 7000 sheets, and winding occurred up to 10,000 sheets. G3: A remarkable offset phenomenon began to be seen from about 5000 sheets, and thereafter winding occurred constantly. G4: A remarkable offset phenomenon began to be seen from about 2500 sheets, and thereafter winding occurred constantly. G5: The offset phenomenon began to be seen before 2500 sheets, and thereafter winding occurred constantly.

(4) Fixing Temperature The fixing temperature was measured using a modified fixing device of A-Color (manufactured by Fuji Xerox Co., Ltd.), and then evaluated by the ironing test method.
(This indicates the heat roll temperature at which an afterimage of a certain area can be exhibited even when ironing stress is applied.) (5) Rubbing Image Intensity Measured using a modified automatic document feeder, Vivece 550 (manufactured by Fuji Xerox Co., Ltd.). 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 levels that do not cause a problem in actual use.) G0: No back-face dirt is generated G1: Some dirt that is difficult to confirm visually is generated G2: Dirt that can be confirmed visually is generated G3: Dirt is visually detected Significant dirt that can be checked enough

(6) Storage stability A standing test was performed at 50 ° C./50% RH for 17 hours.
Thereafter, the mixture was sieved with a 63 μm sieve for 5 minutes to confirm the blocking property. G1: 63 μm sieve passing rate of 70% or more G2: 63 μm sieve passing rate of 40% or more and less than 70% G3: 63 μm sieve passing rate of less than 70% (7) Toner transport amount In each of the examples and comparative examples, hydrophobic colloidal silica was externally used. The toner particles before the addition were added at 40 ° C. and 50% RH.
After holding for 8 hours under the above environment, the toner transport amount per hour was measured by using a modified toner box of a Vivece 800 (manufactured by Fuji Xerox Co., Ltd.).

Tables 1 to 4 show the results of characteristic evaluations performed using the developer compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 18.

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

[Table 4]

[0075]

The electrostatic image developer of the present invention comprises a binder resin, a colorant and a lubricant as essential components, the binder resin being a specific styrene-acrylic copolymer, and a metallocene as a lubricant. Homopolymer obtained by polymerization in the presence of a system catalyst and ethylene and α- having 3 to 10 carbon atoms
A styrene-based monomer and / or an unsaturated carboxylic acid-based monomer graft-modified to a polyethylene-based polymer selected from copolymers with olefins, using a modified polyethylene-based wax with an extraction amount of hexane of 65% by weight or less. Therefore, it can be fixed with lower power consumption, in other words, at a lower temperature, has good offset resistance, and has excellent powder flowability,
Does not cause blocking even in high temperature and high humidity environments.
Furthermore, an image having excellent rubbed image strength can be obtained without being damaged by the peeling nail of the fixing roll portion, and a long life of the fixing roll can be achieved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of a fixing device used in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heating roll, 2 ... Pressure roll, 3 ... Metal core, 4 ...
Elastic layer, 5: metal core, 6: elastic layer, 7: heating source,
8: toner image, 9: peeling nail.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kaori Oishi 1600 Takematsu, Minamiashigara, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Takayoshi Aoki 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Toshiyuki Yano 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (56) References JP-A-6-110249 (JP, A) JP-A-7-104500 (JP, A) JP-A-3-200157 (JP, A) JP-A-5-188640 (JP, A) JP-A-60-3644 (JP, A) JP-A-4-356057 (JP, A) (58) Fields investigated (Int. Cl. ⁶⁾ G03G 9/087 G03G 9/08 G03G 15/20 102 G03G 15/08 507

Claims (7)

(57) [Claims] 1. A toner for developing an electrostatic image containing a binder resin, a colorant and a lubricant, wherein the binder resin has a weight average molecular weight in the range of 1,000 to 50,000 and 100,000 to 100,000.
Styrene-acrylic copolymers each having at least one molecular weight peak in the range of 10,000 and the lubricant is polymerized in the presence of a metallocene-based catalyst to obtain an ethylene homopolymer and ethylene and carbon. Number 3-10
Is a modified polyethylene wax obtained by subjecting a polyethylene polymer selected from copolymers of α-olefins to a styrene monomer and / or an unsaturated carboxylic acid monomer to a hexane extraction of 65% or less. A toner for developing electrostatic images, characterized in that: 2. An electrostatic image developing toner containing a binder resin, a colorant and a lubricant, wherein the binder resin has a molecular weight distribution Mw.
2. The toner for developing an electrostatic image according to claim 1, comprising a styrene-acrylic copolymer having a weight-average molecular weight / Mn (number-average molecular weight) in the range of 20 to 90. 3. An electrostatic image developing toner containing a binder resin, a colorant and a lubricant, wherein the binder resin has a copolymerization ratio of 6
3. The electrostatic image developing toner according to claim 2, comprising a styrene-acrylic copolymer of 0:40 to 90:10. 4. The toner for developing an electrostatic image according to claim 1, wherein the lubricant has a density of 0.95 g / cm ³ or more. 5. The lubricant has a density of 0.95 g / cm ³ or more,
Viscosity average molecular weight 800-3000, molecular weight distribution Mw
(Weight average molecular weight) / Methylene (number average molecular weight) polyethylene polymer 70 to 95 having 1.1 to 1.8
A modified polyethylene wax having a melt viscosity at 160 ° C. of 15 cps to 250 cps and a penetration of 2 dmm or less, obtained by graft-modifying 5 parts by weight of a styrene monomer and / or an unsaturated carboxylic acid monomer at 5 parts by weight. The toner for developing an electrostatic image according to claim 1, wherein: 6. A latent image forming step of forming a latent image on a latent image carrier, a developing step of developing the latent image using a developer, a transfer step of transferring the developed toner image onto a transfer body, 4. An image forming method comprising a fixing step of heating and fixing a toner image on a transfer body, wherein the developer containing the toner for developing an electrostatic image according to claim 1 is used as the developer. Characteristic image forming method. 7. The image forming method according to claim 6, wherein the fixing step uses a fixing device in which an elastic body is provided on the surface of the heat roll.