JP4259629B2 - Toner for electrophotography and toner image fixing method for electrophotography - Google Patents

Description

【００７８】
表１から明らかなように、本発明のトナー及びトナー画像定着方法をもちいた場合比較トナーに比して優れていることが分かる。
【００７９】
【発明の効果】
実施例で実証した如く本発明による電子写真用トナー及び電子写真用トナー画像定着方法は、定着性能に優れ、かつ連続両面コピー時に融着を生じない優れた効果を有する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic toner and an electrophotographic toner image fixing method.
[0002]
[Prior art]
The electrophotographic process forms an electrostatic latent image on the surface of the photoconductor, attaches toner to the latent image with a developing means such as a magnetic brush, transfers the visible image to a transfer material, and finally uses a hot roll or the like. The developer is fused to the transfer material surface to form a permanent image.
[0003]
Toners used for electrophotography are required to have various characteristics, and among them, many inventions have been made so far for the purpose of improving fixing performance.
[0004]
Japanese Patent Publication No. 55-6895 proposes a binder having a molecular weight distribution wide with Mw / Mn = 3.5-40. According to the present invention, both the fixing performance and the hot offset resistance performance can be achieved to some extent with respect to the conventional toner. However, it is still inadequate in terms of fixing performance, and cannot be applied to recent high-speed copying machines.
[0005]
On the other hand, Japanese Patent Laid-Open No. 4-190244 discloses a toner binder comprising a high molecular weight body having a molecular weight of 300,000 or more, a low molecular weight body having a molecular weight of 1000 to 30,000, and an intermediate molecular weight body having a molecular weight of 50,000 to 200,000. Japanese Patent No. 1-2221758 proposes a toner comprising a binder having a molecular weight of 103 to 107 and having at least three maximum values. Certainly, according to these inventions, a toner having excellent fixing performance can be obtained. However, since the molecular weight distribution of the binder resin component in the toner is wide, the dispersion state of the binder resin component cannot be controlled.
[0006]
This distributed state causes a problem that the paper on the paper discharge tray is fused when continuous duplex copying is performed. Further, fixing performance is deteriorated if this fusion is to be eliminated.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide an electrophotographic toner and an electrophotographic toner image fixing method which have excellent fixing performance and do not cause fusing during continuous double-sided copying.
[0008]
[Means for Solving the Problems]
The above object of the present invention is achieved by the following configurations.
[0009]
1. In an electrophotographic toner containing a binder resin, the maximum molecular weight of the binder resin is in the region of 20,000 or less in the molecular weight distribution measured by gel permeation chromatography (GPC).valueComponent A having the molecular weight distribution2B component having a maximum molecular weight in a region exceeding 200,000 and less than 200,000, and C component having a maximum molecular weight in a region having a molecular weight of 200,000 or more in the molecular weight distribution,
A component is a polymer containing 90% by weight or more of styrene and acrylic acid as a monomer component,
B component is a polymer containing styrene, n-butyl acrylate, acrylic acid as a monomer component,
C component is a polymer containing styrene and n-butyl acrylate as monomer components,
When the glass transition point of the A component is TgA, the glass transition point of the B component is TgB, and the glass transition point of the C component is TgC, the following formulas (1) and (2) are satisfied.AndAn electrophotographic toner using a binder resin in which the domain diameter of each of the B component and the C component is dispersed in the A component in a size of 0.2 to 3.0 μm.
  80 (° C.) ≧ TgA> TgC ≧ TgB ≧ 40 (° C.)-(1)
              TgA ≧ 60 (° C.)-(2)
[0010]
2. Said2. The resin component forming a domain contains resin components B and C, and TgA, TgB, and TgC of each resin component satisfy the following formula (2A):Toner for electrophotography.
    TgA> TgC ≧ TgB ≧ 40 (° C.)                              -Formula (2A)
3. 3. Said 1 or 2 characterized by including said resin component A, B, C, and the acid value of binder resin which is comprised of these resin being 0.1-10 (KOHmg / g) Toner for electrophotography.
[0011]
4).In the heat roller fixing device having the heating roller and the pressure roller, the above 1Any one of ~ 3A method for fixing an electrophotographic toner image, comprising: transporting a visible image obtained by the electrophotographic toner described in 1) under a narrow pressure, bringing the toner image into contact with a heat roller, and fixing the recording material under pressure and heat.
[0012]
Hereinafter, the present invention will be described in more detail.
[0013]
The electrophotographic toner of the present invention is an electrophotographic toner containing a binder resin. The binder resin contains a low molecular weight component (A component), a medium molecular weight component (B component), and a high molecular weight component (C component). To do.
[0014]
In the present invention, the low molecular weight component (hereinafter referred to as component A) is a component having a maximum molecular weight in a region of 20,000 or less in the molecular weight distribution measured by gel permeation chromatography (hereinafter referred to as GPC).
[0015]
In the present invention, the medium molecular weight component (hereinafter referred to as “B component”) is a component having a maximum molecular weight in the region of molecular weight exceeding 20,000 and less than 200,000 in the molecular weight distribution measured by GPC.
[0016]
In the present invention, the high molecular weight component (hereinafter referred to as C component) is a component having a maximum molecular weight in a region having a molecular weight of 200,000 or more in a molecular weight distribution measured by GPC.
[0017]
In the electrophotographic toner of the present invention, the A component, the B component, and the C component have different configurations. This is because if the components A, B and C are identical in structure, it is impossible to obtain an appropriate dispersion state of each component. The components A, B, and C of the electrophotographic toner of the present invention are different from each other in that the components A, B, and C are different from each other in the monomer composition. The ratio of is different.
[0018]
In the present invention, the polymer refers to a polymer composed of a single monomer component and a copolymer composed of two or more monomer components.
[0019]
The toner for electrophotography of the present invention satisfies the following formulas (1) and (2) when the glass transition point of the A component is TgA, the glass transition point of the B component is TgB, and the glass transition point of the C component is TgC. To do.
[0020]
80 (° C.) ≧ TgA> TgC ≧ TgB ≧ 40 (° C.)-(1)
TgA ≧ 60 (° C.)-(2)
Since component A is a thermally unstable component, if TgA is less than 60 ° C., fusion cannot be prevented. If the temperature exceeds 80 ° C., the fixing performance cannot be satisfied.
[0021]
Since component B is thermally stable and contributes to improvement in fixing performance,
TgA> TgC ≧ TgB
Must. Further, if TgB is less than 40 ° C., fusion during continuous duplex copying cannot be prevented.
[0022]
The C component is a component that mainly contributes to prevention of offset. However, when TgC is TgA or more, the fixing performance is deteriorated. If TgC is less than TgB, fusion during continuous duplex copying cannot be prevented.
[0023]
The electrophotographic toner of the present invention is formed by dispersing each domain diameter of the B component and the C component in the A component so as to have a size of 0.2 to 3 μm.
[0024]
As a result of intensive studies, the present inventors have found that B component and C component, which are highly viscous components, are not completely compatible with A component, which is a low viscosity component, and the domain diameters of B component and C component are It has been found that excellent fixing performance can be obtained by dispersing in a size of 0.2 μm or more. Further, when the domain diameter is 3 μm or less, fusion during continuous double-sided copying can be prevented.
[0025]
In the present invention, the domain diameter of the binder resin is measured by the following method.
[0026]
A thin slice having a thickness of 20 nm was cut out from the synthesized binder resin solid. The thin slice was observed at a magnification of 5,000 using a transmission electron microscope. The obtained image was analyzed and the domain diameter was measured.
[0027]
In the present invention, the component A is preferably contained in the binder resin in an amount of 50 wt% to 60 wt%. If it is less than 50 wt%, the fixing performance deteriorates. When it exceeds 60 wt%, an offset is generated.
[0028]
In the present invention, the B component is preferably contained in the binder resin in an amount of 10 wt% to 25 wt%. If it is less than 10 wt%, fusion occurs during continuous duplex copying. If it exceeds 25 wt%, an offset occurs.
[0029]
In the present invention, the C component is preferably contained in the binder resin at 15 wt% or more and 30 wt% or less. If it is less than 15 wt%, an offset occurs. If it exceeds 30 wt%, the fixing performance deteriorates.
[0030]
The glass transition point of the binder resin in the electrophotographic toner of the present invention is measured by the following method. 5 mg of the binder resin component is weighed into an aluminum pan and sealed. The sample is heated from 0 ° C. to 200 ° C. at a rate of temperature increase of 10 ° C./min, left at that temperature for 3 minutes, and then cooled to 0 ° C. at a temperature decrease rate of 10 ° C./min. Then, the temperature is raised to 200 ° C. at a temperature raising rate of 10 ° C./min. The glass transition point is the intersection of the extension line of the base line of the caloric change curve at the second temperature rise and the extension line of the close contact point where the caloric change curve shows the maximum slope between the rising part and the peak of the endothermic peak. To do. A differential scanning calorimeter DSC-7 manufactured by Perkin Elmer was used as a measuring machine.
[0031]
The binder resin of the present invention is preferably selected from the following resins.
[0032]
As vinyl resin, styrene monomer and / or acrylic acid or methacrylic acid ester monomer, and acrylic acid or methacrylic acid monomer as a component having a carboxyl group in the side chain Combines can be used.
[0033]
Examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,3-dimethylstyrene, and 2,4-dimethylstyrene. , Pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, Examples thereof include p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene and the like. Of these, styrene is preferred.
[0034]
Examples of the acrylic ester or methacrylic ester monomers include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic acid-n-octyl, acrylic acid dodecyl, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylic acid-n-butyl, isobutyl methacrylate, methacrylic acid-n-octyl, dodecyl methacrylate, methacrylic acid-2- Acrylic acid such as ethylhexyl and stearyl methacrylate or alkyl esters of methacrylic acid, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, phenyl methacrylate, dimethylamino methacrylate Alkenyl, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate. Among these, acrylic acid or alkyl esters of methacrylic acid such as ethyl acrylate, propyl acrylate-n-butyl, ethyl methacrylate, propyl methacrylate, and methacrylic acid-n-butyl are preferable, and acrylic acid-n- Butyl, methyl methacrylate, methacrylic acid-n-butyl and the like are preferable.
[0035]
As acrylic acid and methacrylic acid monomers, acrylic acid and methacrylic acid are preferred.
[0036]
Further, solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization are used for the polymerization of the styrene-acryl component. Among these, solution polymerization and suspension polymerization are most preferably used.
[0037]
The binder resin used in the electrophotographic toner of the present invention preferably contains an acrylic acid monomer as a constituent unit in the B component or the A component and the B component. This is because when B component or A component and B component contain an acrylic acid monomer as a constituent unit, fixing performance is improved.
[0038]
The content of the acrylic acid monomer in the component A is preferably 2 wt% or less.
[0039]
The content of the acrylic monomer in the component B is preferably 3 wt% or less.
[0040]
The acid value of the binder resin used in the electrophotographic toner of the present invention is preferably from 0.1 to 10. If it is less than 0.1, the effect of improving the fixing performance is not exhibited. When the acid value of the binder resin exceeds 10, the charging performance of the toner becomes unstable.
[0041]
In the present invention, the acid value is the amount of potassium hydroxide required to neutralize the free acid and fatty acid contained in 1 g of the binder resin.
[0042]
In the present invention, the acid value is measured as follows. 2 g of the measurement sample is dissolved in 75 ml of toluene, and 25 ml of a neutralized methanol: acetone = 1: 1 mixture is added thereto. The resulting solution is subjected to potentiometric titration with a 0.1N alcoholic KOH solution having a titer = F.
[0043]
The titration amount up to the inflection point of the potential difference is obtained and calculated by the following formula.
[0044]
Acid value (KOHmg / g) = 5.61 × titer × (titrate to inflection point; ml) / 2
The binder resin used in the electrophotographic toner of the present invention is a mixture of a high molecular weight body, a medium molecular weight body and a low molecular weight body in a solvent in which these resins are soluble, and then the solvent is removed. Can be obtained.
[0045]
Examples of the solvent in which the above resin is soluble include benzene, toluene, xylene, cumene and the like. Among these, toluene and xylene are particularly preferably used.
[0046]
It is presumed that the domain diameter is determined by the viscosity difference between the high molecular weight body, the medium molecular weight body, and the low molecular weight body during heating and mixing in a solvent.
[0047]
The electrophotographic toner of the present invention is produced as follows.
[0048]
After dry blending the binder resin component, colorant, wax, and magnetic powder as required, melt knead so that each composition in the toner becomes uniform using an extruder, kneader, kneading roll machine, closed mixer, etc. Then, after cooling, the mixture is finely pulverized by a jet mill, a turbo mill or the like, and obtained by dry blending a classified toner having a predetermined particle size after classification, an external additive such as silica, and a cleaning aid if necessary.
[0049]
A wax may be used for the electrophotographic toner of the present invention, and the wax may be a low molecular weight polyolefin such as polypropylene or polyethylene and derivatives thereof, an alkylene bis fatty acid amide compound, paraffin wax, or a combination of two or more thereof. Etc. are preferably used. The wax content is usually 1 to 20 parts by weight, particularly 2 to 15 parts by weight, based on 100 parts of the binder resin.
[0050]
When the electrophotographic toner of the present invention is used as a magnetic toner, iron oxides such as magnetite, hematite, ferrite, etc., metals such as iron, nickel, cobalt or these metals and aluminum, cobalt, copper, lead, magnesium, A magnetic material selected from alloys with metals such as tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium can be used.
[0051]
The magnetic material preferably has a volume average particle size of 0.1 to 2 [mu] m, more preferably 0.1 to 0.5 [mu] m. The amount contained in the electrophotographic toner of the present invention is preferably 40 to 150 parts by weight per 100 parts by weight of the binder resin component.
[0052]
The electrophotographic toner of the present invention may contain a colorant as appropriate. This colorant includes carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, dupont oil red, orient oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, Examples include rose bengal.
[0053]
The fixing device used in the electrophotographic toner image fixing method of the present invention is a heat roller fixing device having a heat roller and a pressure roller. Furthermore, the electrophotographic toner image fixing method of the present invention uses the above-mentioned heat roller fixing device, and conveys the visible image obtained by the electrophotographic toner of the present invention with a narrow pressure, and presses the recording material by contacting with the heat roller. This is a heat fixing method.
[0054]
The heat roller fixing device includes an upper roller having a heat source inside a metal cylinder composed of iron, aluminum, or the like whose surface is coated with tetrafluoroethylene or polytetrafluoroethylene-perfluoroalkoxy vinyl ether copolymers, and silicon. It is preferably formed from a lower roller made of rubber or the like. Specifically, it is preferable to have a linear heater as a heat source and to heat the surface temperature of the upper roller to about 120 to 200 ° C., and in the fixing part, a pressure is applied between the upper roller and the lower roller. In addition, the lower roller is deformed to form a so-called nip. The nip width is preferably 1 to 10 mm, more preferably 1.5 to 7 mm. The fixing linear velocity is preferably 40 mm / sec to 400 mm / sec. When the nip is narrow, the visible image obtained by the electrophotographic toner of the present invention is uniformly transported with heat, and it becomes impossible to press and heat-fix the recording material in contact with the heat roller. Unevenness occurs. On the other hand, when the nip width is wide, the melting of the binder resin is promoted, which causes a problem of excessive fixing offset.
[0055]
If necessary, the heat roller fixing device may be provided with a fixing cleaning mechanism. In this case, a method of supplying silicon oil to the upper roller or film of the fixing device or a method of cleaning with a pad, roller, web, etc. impregnated with silicon oil can be used. As the silicon oil, those having high heat resistance are preferably used. For example, polydimethylsilicon, polyphenylmethylsilicon, or the like is preferably used. Since silicon oil having a low viscosity has a large outflow during use, one having a viscosity of 1000 to 100,000 cps at 20 ° C. is preferably used.
[0056]
【Example】
Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto.
[0057]
Binder resin production example 1 of the present invention
Consisting of 99 parts by weight of styrene and 1 part by weight of acrylic acid, 55 parts by weight of component A having a maximum molecular weight of 3,800 and a glass transition point of 64 ° C., 71 parts by weight of styrene, 27 parts by weight of n-butyl acrylate and 2 parts by weight of acrylic acid It consists of 20 parts by weight of B component, 80 parts by weight of styrene and 20 parts by weight of n-butyl acrylate having a maximum molecular weight of 110,000 and a glass transition point of 50 ° C., and a maximum molecular weight of 650,000 and a glass transition point of 60 ° C. 25 parts by weight of a certain C component was mixed in xylene under reflux. The binder resin solution was dried under reduced pressure to obtain a binder resin 1. When the obtained binder resin was observed with a transmission electron microscope, the domain diameter of each of the B component and the C component was dispersed in the A component in a size of 0.25 to 2.8 μm. The acid value was measured and found to be 7.1 KOHmg / g.
[0058]
Binder resin production example 2 of the present invention
It consists of 55 parts by weight of component A having a maximum molecular weight of 4,400 and a glass transition point of 67 ° C. made of styrene, 71 parts by weight of styrene, 27 parts by weight of n-butyl acrylate and 2 parts by weight of acrylic acid, and a maximum molecular weight of 100,000. And 25 parts by weight of the B component having a glass transition point of 50 ° C., 70 parts by weight of styrene and 30 parts by weight of n-butyl acrylate, and having a maximum molecular weight of 750,000 and 20 parts by weight of the C component having a glass transition point of 50 ° C. Mixed under reflux in xylene. The binder resin solution was dried under reduced pressure to obtain a binder resin 2. When the obtained binder resin was observed with a transmission electron microscope, the domain diameters of the B component and the C component were dispersed in the A component in a size of 0.22 to 2.5 μm. The acid value measured was 2.9 KOHmg / g.
[0059]
Binder resin production example 3 of the present invention
Consists of 60 parts by weight of component A having a maximum molecular weight of 4,100 and a glass transition point of 65 ° C. made of styrene, 65 parts by weight of styrene, 33 parts by weight of n-butyl acrylate, and 2 parts by weight of acrylic acid, and a maximum molecular weight of 100,000. And 15 parts by weight of B component having a glass transition point of 50 ° C., 70 parts by weight of styrene and 30 parts by weight of n-butyl acrylate, and having a maximum molecular weight of 750,000 and 25 parts by weight of C component having a glass transition point of 50 ° C. The mixture was mixed under reflux. The binder resin solution was dried under reduced pressure to obtain a binder resin 3. When the obtained binder resin was observed with a transmission electron microscope, the domain diameters of the B component and the C component were dispersed in the A component in a size of 0.22 to 2.5 μm. The acid value was measured and found to be 3.1 KOHmg / g.
[0060]
Comparative binder resin production example 1
Consisting of 99 parts by weight of styrene and 1 part by weight of acrylic acid, 55 parts by weight of component A having a maximum molecular weight of 2,900 and a glass transition point of 55 ° C., 71 parts by weight of styrene, 27 parts by weight of n-butyl acrylate, 2 parts by weight of acrylic acid It consists of 20 parts by weight of B component, 80 parts by weight of styrene and 20 parts by weight of n-butyl acrylate having a maximum molecular weight of 110,000 and a glass transition point of 50 ° C., and a maximum molecular weight of 650,000 and a glass transition point of 60 ° C. 25 parts by weight of a certain C component was mixed in xylene under reflux. The binder resin solution was dried under reduced pressure to obtain comparative binder resin 1. When the obtained binder resin was observed with a transmission electron microscope, the domain diameter of each of the B component and the C component was dispersed in the A component in a size of 0.25 to 2.8 μm. The acid value was measured and found to be 4.1 KOHmg / g.
[0061]
Comparative binder resin production example 2
The maximum molecular weight is 110,000 consisting of 60 parts by weight of component A having a maximum molecular weight of 3,000 and a glass transition point of 57 ° C., 68 parts by weight of styrene, 30 parts by weight of n-butyl acrylate and 2 parts by weight of acrylic acid. And 15 parts by weight of B component having a glass transition point of 48 ° C., 80 parts by weight of styrene and 20 parts by weight of n-butyl acrylate, and 25 parts by weight of C component having a maximum molecular weight of 650,000 and a glass transition point of 60 ° C. The mixture was mixed under reflux. The binder resin solution was dried under reduced pressure to obtain a comparative binder resin 2. When the obtained binder resin was observed with a transmission electron microscope, the domain diameters of the B component and the C component were dispersed in the A component in a size of 0.22 to 2.2 μm. The acid value was measured and found to be 2.2 KOHmg / g.
[0062]
Comparative binder resin production example 3
Consisting of 85 parts by weight of styrene and 15 parts by weight of butyl acrylate, maximum molecular weight of 10,000, 70 parts by weight of component A having a glass transition point of 55 ° C., 80 parts by weight of styrene and 20 parts by weight of n-butyl acrylate 30 parts by weight of component C having a glass transition point of 60 ° C. and 1,000, were mixed in xylene under reflux. The binder resin solution was dried under reduced pressure to obtain comparative binder resin 3. When the obtained binder resin was observed with a transmission electron microscope, dispersion was not confirmed. The acid value was measured and found to be 2.2 KOHmg / g.
[0063]
Comparative binder resin production example 4
It consists of 99 parts by weight of styrene and 1 part by weight of acrylic acid and has a maximum molecular weight of 3,600, 70 parts by weight of component A having a glass transition point of 61 ° C., 80 parts by weight of styrene and 20 parts by weight of n-butyl acrylate, and a maximum molecular weight of 650. 30 parts by weight of component C having a glass transition point of 60 ° C. and 1,000, were mixed in xylene under reflux. The binder resin solution was dried under reduced pressure to obtain comparative binder resin 4. When the obtained binder resin was observed with a transmission electron microscope, the domain diameter of each C component was dispersed in the A component in a size of 0.4 to 6.0 μm. The acid value measured was 5.2 KOHmg / g.
[0064]
(Example of toner production for electrophotography)
Production example 1 of electrophotographic toner of the present invention
100 parts by weight of the binder resin 1 of the present invention, 10 parts by weight of carbon black, and 4 parts by weight of polypropylene wax were melt-kneaded with a biaxial roll kneader and then pulverized with a jet mill. A toner composition having a volume average particle size of 8.5 μm was obtained using an air classifier. To 100 parts by weight of this toner composition, 1 part by weight of hydrophobic silica was added and mixed with a dry mixer to obtain toner 1 for electrophotography of the present invention (hereinafter also simply referred to as toner 1).
[0065]
Production Examples 2-3 of Toner for Electrophotography of the Present Invention
Except for the binder resin 1 of the electrophotographic toner production example 1 of the present invention, the binder resins 2 to 3 of the present invention were used in the same manner, and the electrophotographic toners 2 to 3 of the present invention (hereinafter simply referred to as toner 2 and toner). 3).
[0066]
Comparative electrophotographic toner production examples 1 to 4
Comparative electrophotographic toners 1 to 4 (hereinafter, also simply referred to as comparative toners 1 to 4) were obtained in the same manner except that the binder resin 1 of the electrophotographic toner production example 1 was used.
[0067]
(Evaluation of toner for electrophotography)
6 parts by weight of the electrophotographic toners 1 to 3 and comparative electrophotographic toners 1 to 4 of the present invention and 100 parts by weight of a fluorinated carrier (volume average particle size 65 μm) were mixed and used for evaluation of actual images.
[0068]
The following evaluations (1) to (3) were performed, and the results are summarized in Table 1.
[0069]
(1) Fixing performance
The fixing machine set temperature was set to an arbitrary temperature and images were taken out. The image was rubbed with an exposed cotton cloth, and the change in reflection density before and after rubbing was measured as the fixing rate. The fixing ratio was calculated as (reflection density after rubbing / reflection density after rubbing). In the evaluation, a fixing rate of 70 or more was evaluated as ◯ (good), and less than 70% was evaluated as x (problem).
[0070]
In the fixing test, a 3135 copier manufactured by Konica Corporation was used by modifying it so as to have the configuration of the electrophotographic toner image fixing method of the present invention.
[0071]
The fixing machine has a heater at the center, an iron cylindrical upper roller having a diameter of 40 mm whose surface is coated with a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer on the surface. And a lower roller having a diameter of 40 mm and coated with silicon rubber coated with. The linear pressure was 1.0 kg / cm and the nip width was 5.0 mm. The linear velocity was 270 mm / sec and the upper roller temperature was 160 ° C. No cleaning mechanism was installed.
[0072]
(2) Hot offset resistance
The fixing device satisfying the configuration of the electrophotographic toner image fixing method of the present invention was set at an arbitrary temperature, and 100 continuous copies were made to visually determine the presence or absence of hot offset. The evaluation was “◯” when no occurrence of hot offset was observed, and “×” when occurrence of hot offset was observed.
[0073]
In the offset test, a 3135 copier manufactured by Konica Corp. was modified so as to have the configuration of the electrophotographic toner image fixing method of the present invention.
[0074]
The fixing machine has a heater at the center, an iron cylindrical upper roller having a diameter of 40 mm whose surface is coated with a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer on the surface. And a lower roller having a diameter of 40 mm and coated with silicon rubber coated with. The linear pressure was 1.0 kg / cm and the nip width was 5.0 mm. The linear velocity was 180 mm / sec and the upper roller temperature was 200 ° C. No cleaning mechanism was installed.
[0075]
(3) Fusion
A 3135 copier manufactured by Konica Co., Ltd. was remodeled and used so as to have the configuration of the electrophotographic toner image fixing method of the present invention. The evaluation was “◯” when no fusion was observed, and “X” when it was observed.
[0076]
A fixing device satisfying the configuration of the electrophotographic toner image fixing method of the present invention has a heater in the center, and an iron cylindrical upper roller having a diameter of 40 mm and having a surface coated with a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer. And a lower roller having a diameter of 40 mm coated with silicon rubber coated with a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer on the surface. The linear pressure was 1.0 kg / cm and the nip width was 5.0 mm. The linear velocity was 230 mm / sec and the upper roller temperature was 200 ° C.
[0077]
[Table 1]

[0078]
As can be seen from Table 1, when the toner of the present invention and the toner image fixing method are used, the toner is superior to the comparative toner.
[0079]
【The invention's effect】
As demonstrated in the examples, the electrophotographic toner and the electrophotographic toner image fixing method according to the present invention are excellent in fixing performance and have an excellent effect of not causing fusion during continuous double-sided copying.

Claims (2)

In an electrophotographic toner containing a binder resin, A component having a maximum value of molecular weight of 20,000 or less in the region in the molecular weight distribution measured by the binder resin is a gel permeation chromatography (GPC), the molecular weight distribution 20,000, greater in the B component and the molecular weight distribution has a maximum value of the molecular weight region of less than 200,000, containing C component having the maximum value of the molecular weight on the molecular weight of 200,000 or more areas,
A component is a polymer containing 90% by weight or more of styrene and acrylic acid as a monomer component,
B component is a polymer containing styrene, n-butyl acrylate, acrylic acid as a monomer component,
C component is a polymer containing styrene and n-butyl acrylate as monomer components,
The glass transition temperature of component A TgA, TgB a glass transition point of the B component, when the TgC the glass transition point of the component C, and satisfies the following formula (1) and (2), one 且, in component A An electrophotographic toner using a binder resin in which the domain diameter of each of the B component and the C component is dispersed in a size of 0.2 to 3.0 μm.
80 (° C.) ≧ TgA> TgC ≧ TgB ≧ 40 (° C.)-(1)
TgA ≧ 60 (° C.)-(2)   A visible image obtained by the electrophotographic toner according to claim 1 is conveyed in a narrow pressure to a heat roller fixing device having a heat roller and a pressure roller, and the recording material is heated under pressure by contacting the heat roller. A toner image fixing method for electrophotography, comprising fixing.