JP3000516B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which is used in an image forming method such as an electrophotographic method and an electrostatic recording method and which heats and fixes an unfixed image on a transfer material.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
As described in Japanese Patent Application Publication No. JP-B-43-24748 and Japanese Patent Publication No. 43-24748, generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. Forming and then developing the latent image with toner,
Using a direct or indirect means as necessary, after transferring the toner image to a transfer material such as paper, fixing by heating, pressure, heating and pressurizing or solvent vapor, etc. to obtain a copy, and The toner remaining on the photoreceptor without being transferred is cleaned by various methods, and the above steps are repeated.

Further, a general method of forming a full-color image will be described. The photosensitive member of a photosensitive drum is uniformly charged by a primary charger, and image exposure is performed by a laser beam modulated by a magenta image signal of a document. To form an electrostatic latent image on the photosensitive drum, and develop the electrostatic latent image by a magenta developing device having magenta toner to form a magenta toner image. Next, the magenta toner image developed on the photosensitive drum by the transfer charger is transferred to the conveyed transfer material using direct or indirect means.

On the other hand, the photosensitive drum after the development of the electrostatic latent image is neutralized by a static eliminator, cleaned by a cleaning unit, and charged again by a primary charger. A cyan toner image is formed and the cyan toner image is transferred to a transfer material on which the magenta toner image has been transferred.
The same procedure is performed in the same manner as for the black color to transfer the four color toner images to the transfer material. The transfer material having the four color toner images is fixed by the action of heat and pressure by a fixing roller to form a full color image.

[0005] In recent years, such devices have begun to be used not only as office work copiers for copying original manuscripts, but also as printers as personal computer outputs or personal copies for individuals.

[0006] In addition to such fields represented by laser beam printers, the development of plain paper faxes using a basic engine has been rapidly developing.

For this reason, smaller, lighter, faster, higher image quality, and higher reliability have been strictly pursued, and machines have been constructed with simpler elements in various respects. . As a result, the performance required of the toner has become higher, and if the performance of the toner cannot be improved, a better machine cannot be realized. Further, in recent years, demands for color copying have been rapidly increasing along with various copying needs, and further higher image quality, higher resolution, etc. are desired in order to more faithfully copy original color images. From these viewpoints, the toner used in the color image forming method needs to have good meltability and color mixing when heat is applied thereto, and has a low softening point and a low melt viscosity. It is preferable to use a toner having a high melting property.

That is, by using such a sharp melt toner, the color reproduction range of a copy can be widened and a color copy faithful to the original image can be obtained.

However, such a color toner having a high sharp melt property generally has a high affinity with a fixing roller, and tends to be easily offset to the fixing roller during fixing.

Particularly, in the case of a fixing device in a color image forming apparatus, since a plurality of toner layers of magenta, cyan, yellow, and black are formed on a transfer material, offset tends to occur particularly due to an increase in toner layer thickness. It is in.

Conventionally, for the purpose of preventing toner from adhering to the surface of the fixing roller, for example, the roller surface is formed of a material having excellent releasability from the toner, such as silicone rubber or fluorine-based resin. In order to prevent surface fatigue, the roller surface is coated with a thin film of a highly releasable liquid such as silicone oil or fluorine oil. However, this method is extremely effective in preventing toner offset, but has a problem that a fixing device is complicated because a device for supplying an anti-offset liquid is required. Needless to say, this oil application causes delamination between the layers constituting the fixing roller, and consequently shortens the life of the fixing roller.

Further, Japanese Patent Application Laid-Open No. 63-313182 proposes a heating apparatus of a film heating system. Since a heating element with a fast temperature rise and a thin fixing film having a small heat capacity are used, the thermal efficiency is good and the wait time can be reduced (quick start). It has the advantages of energy saving, no problem with toner offset for black toner images, and a simple device configuration. However, even with such a film heating type apparatus, when a full-color image is formed, it is easy to offset the fixing film, and a long cooling step after heating to separate the fixing film, or a means such as providing a separate cooling means such as a fan, is required. Indispensable, the equipment cost was high.

As a transfer material for fixing a toner image using these fixing devices, various papers, coated papers, plastic films and the like are generally used. In particular, the necessity of a transparency film (OHP) using an overhead projector for presentation has recently attracted attention. In particular, OHP differs from paper in that the oil absorption capacity is low, so the copy OHP that can be obtained at present
However, the greasy feeling due to oil application is inevitable, and a great problem remains in the quality of the obtained image. In addition, silicone oil etc. evaporates due to heat, contaminating the inside of the machine,
There is a high possibility that problems such as the treatment of the recovered oil will occur.
So without using a silicone oil supply device,
Instead, a method of adding a release agent such as low-molecular-weight polyethylene or low-molecular-weight polypropylene to the toner has been proposed in view of supplying the anti-offset liquid from the toner during heating. However, if such an additive is added in a large amount in order to obtain a sufficient effect, filming on the photoreceptor and contamination of the surface of the toner carrier such as a carrier or a sleeve are deteriorated, and the image is deteriorated, which is a practical problem. Become. Therefore, a small amount of release agent is added to the toner to the extent that the image is not deteriorated, and a small amount of release oil is supplied or the offset toner is taken up using a device such as a web-type member or a cleaning pad. It is common to use a cleaning device together.

However, particularly in the field of full color, the means for containing a release agent as in the prior art, when using OHP as a transfer material, causes high crystallization of the release agent and a difference in refractive index from the resin. Therefore, there arises a problem that the transparency and haze of the image after fixing are slightly reduced.

It is known that a wax is contained in a toner as a release agent. For example, Japanese Patent Publication No. 52-3304
JP, JP-B-52-3305, JP-A-57-5-5
The technology is disclosed in 2574 and the like.

Also, JP-A-3-50559, JP-A-2-79860, JP-A-1-109359, JP-A-62-14166, and JP-A-61-27
3554, JP-A-61-94062, JP-A-61-138259, JP-A-60-25236
No. 1, Japanese Unexamined Patent Publication No. 60-252360, Japanese Unexamined Patent Publication No.
Japanese Patent Application Laid-Open No. 0-217366 discloses a technique for containing waxes.

Waxes are used to improve the anti-offset property of toner at low and high temperatures and to improve the fixability at low temperature, but on the other hand, it deteriorates anti-blocking properties, and is used in copiers and the like. If the toner is exposed to heat due to a rise in temperature or the like, the developability deteriorates, and when the toner is left for a long period of time, the wax migrates to the toner surface to deteriorate the developability.

None of the conventional toners satisfies all of these aspects, causing some problems. For example, high-temperature offset resistance and developability are excellent, but low-temperature fixability is just one step away, or low-temperature offset and low-temperature fixability are excellent, but blocking resistance is slightly inferior, and developability at elevated temperatures in the machine And the offset resistance at low and high temperatures cannot be compatible.
P transparency was extremely bad.

In particular, regarding the transparency of OHP, a proposal has been made to add a crystallization nucleating agent or the like to wax in order to reduce crystallization of the wax itself (JP-A-4-149559 and JP-A-4-107467). Proposes to use wax having a low crystallinity (Japanese Patent Application No. 3-09110).
No. 8, JP-A-3-242397) and a substance having good compatibility with a binder and a lower melt viscosity than the binder are added to the binder, so that the surface smoothness of the toner layer after fixing is improved. Is proposed in Japanese Patent Application No. 3-21.
2652.

One of the release agents having relatively good transparency and low-temperature fixing performance is montan wax, which is a mineral wax.

The following structural formula is used as the montan wax.

[0022]

Embedded image

Wherein R represents a hydrocarbon group having 28 to 32 carbon atoms, and n represents an integer.
JP-A-1-185660.
JP, JP-A-1-185661, JP-A-1-1-1
No. 85662, Japanese Patent Application Laid-Open No. 1-185663, and Japanese Patent Application Laid-Open No. 1-238672 have been proposed. However, none of these is fully satisfactory in terms of transparency and haze (cloudiness) of OHP.

On the other hand, in order to inhibit the crystallinity of the release agent itself, Japanese Patent Application No. 5-11851 discloses the use of an ester wax in which the structure of the release agent itself is broken.
7, Japanese Patent Application No. 5-126180, Japanese Patent Application No. 5-126180.
No. 126181, and fairly good results have been obtained.

However, even in recent full-color fixing devices, high durability and high reliability have been required, and improvement of the toner binder resin, release agent and the like alone without improvement of the fixing device reduces the image area from high image area to low image quality. Image area image,
Furthermore, it is difficult to stably realize an image forming method applicable to a full-color OHP over a long period of time, and further improvement is desired.

[0026]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus which solves the above-mentioned problems.

Another object of the present invention is to provide an image forming apparatus having excellent low-temperature fixability to a recording material and anti-offset properties over a long period of time.

Still another object of the present invention is to provide an image forming apparatus which can fix without applying a large amount of oil or without applying any oil.

Still another object of the present invention is to provide an image forming apparatus capable of obtaining a high-quality full-color OHP excellent in transparency.

Still another object of the present invention is to form a full-color image in a film heating type apparatus by taking a long cooling step after heating in order to separate the fixing film without offsetting the fixing film, or separately using a fan or the like. An object of the present invention is to provide an image forming apparatus which requires no means such as providing a cooling means and has a low apparatus cost.

[0031]

According to the present invention, there is provided an image forming apparatus for fixing an unfixed toner image carried on a recording material to the recording material by a fixing device which heats and / or presses with a pressing member. Wherein the toner is a toner containing at least a binder resin, a colorant, and a wax, and has a pressure roller that is pressed into contact with the pressure member so as to form a nip. An elastic layer having heat resistance and a flexural modulus A (kgf / cm ² ) of a surface resin of the pressure-contact member at 23 ° C. around the base sheet made of polyimide are 4000 ≦ A ≦ 10,000 The pressure roller is provided with a heat-resistant elastic layer around a cored bar and a flexural modulus B (kgf / kg) of the surface resin at 23 ° C. of the pressure roller.
cm ² ), when a surface layer having a releasability of 4000 ≦ B ≦ 10000 is provided and the surface hardness (Hs) of the pressing member and the pressure roller is C degree, 1 ≦ C ≦ 90; The elastic layer of the press-contact member has a thermal conductivity D (ca
l / cm · sec · ° C.) is 0.2 × 10 ⁻³ ≦ D ≦ 2 × 10 ⁻³ , and the thickness T (mm) is 0.1 ≦ T ≦ 3. The present invention relates to an image forming apparatus, wherein a linear pressure E (kg / cm) at the time of pressing a member against a pressure roller is 0.8 ≦ E ≦ 2.0, and the nip is formed substantially flat.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of diligent research, the present inventor has found that, by satisfying the above-mentioned conditions for the pressing member and the pressing roller, a part or all of the wax forms an appropriate coating and the toner It has been found that a full-color OHP having excellent transparency can be produced without offset, good offset resistance can be maintained, and the life of the press-contact member can be extended.

The measurement of the flexural modulus in the present invention was performed on the surface material of the press-contact member according to ASTM test method D790. As the surface hardness (A-type spring hardness: JIS K6301), a value measured by a commercially available polymer meter was used.

The pressure contact member is preferably made of polyimide as a base sheet, and the thickness of the base sheet is preferably 10 to 120 μm.

The flexural modulus A and B is 4000 kgf
/ Cm ² , the wax finely dispersed in the unfixed toner at the time of fixing or compatible with the binder is re-aggregated,
The color reproducibility may decrease, or the transparency of full-color OHP may decrease. On the other hand, 10,000 kgf / cm ²
If it is larger, it cannot be homogenized on the pressing member, and as a result, fixing unevenness, partial offset and the like will occur, and the paper cannot be discharged.

The surface hardness Hs (degree C) of the pressing member and the pressure roller, the thermal conductivity (D) of the elastic layer of the pressing member
cal / cm · sec · ° C.) and thickness (Tmm), and when the linear pressure (Ekg / cm) at the time of press-contacting the press-contact member and the press roller is out of the above-mentioned range, the base and the core metal are not subjected to the above-mentioned ranges. Reflecting the rigidity, minute gloss unevenness occurs due to unevenness of the paper surface, or the elasticity is insufficient, and similarly, minute gloss unevenness occurs. Of course, since a substantially flat nip cannot be formed, paper transportability becomes unstable and paper wrinkles occur. The thickness of the surface layer of the pressing member is preferably 5 to 50 μm, and the thickness of the surface layer of the pressure roller is preferably 5 to 120 μm.

As the wax of the toner used in the present invention, a low crystal having a suitable affinity for the binder resin, a high hydrophobicity and a low melting point for exhibiting good low-temperature fixability and offset resistance. Are preferred. Furthermore, the molecular weight distribution of the wax has at least two peaks and / or shoulders, and the weight average molecular weight (M
w) is 400 or more and 4000 or less, number average molecular weight (Mn)
Is preferably 200 or more and 4000 or less. It has been found that the above-mentioned molecular weight distribution may be achieved by a single compound or a plurality of compounds, and as a result, the crystallinity can be inhibited and the transparency is further improved. The method of blending two or more waxes is not particularly limited. For example, a media-type dispersing machine (ball mill, sand mill, attritor, apex mill, co-ball mill, handy mill) or the like having a melting point equal to or higher than the melting point of the wax to be blended is used. It is also possible to use them for melt blending, or to dissolve wax to be blended in a polymerizable monomer and blend them with a media type disperser or the like. At this time, pigments, charge control agents, polymerization initiators, etc. may be used as additives.

In the present invention, the molecular weight distribution of the wax is G
It is measured by a PC under the following conditions.

[0039] (GPC Measurement Condition) Device: GPC-150C (manufactured by Waters Corporation) Column: GMH-HT30cm ² consecutive (Tosoh Corporation) Temperature: 135 ° C. The solvent: o-dichlorobenzene (0.1% Aionoru added) Flow rate: 1.0 ml / min sample: 0.4 ml of 0.15% sample is injected

Measurement is performed under the above conditions, and the molecular weight of the sample is calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample. In addition, Mark-Hou
It is calculated by converting to polyethylene using a conversion formula derived from the wink viscosity formula.

The weight average molecular weight (Mw) of the wax is 40
The number average molecular weight (Mn) is preferably from 0 to 4000 and from 200 to 4000. More preferably, Mw is 400 or more and 3000 or less, and still more preferably 40 or more.
0 or more and 2000 or less, Mn is 200 or more and 3000 or less,
More preferably, it is desired to be 200 or more and 2000 or less. When Mw is less than 400 and Mn is less than 200, the blocking resistance of the toner is significantly deteriorated. When Mw exceeds 4000 and Mn exceeds 4000, the crystallinity of the wax itself is developed, and the transparency is significantly deteriorated.

The wax is preferably used in an amount of 1 to 40 parts by weight (preferably 2 to 30 parts by weight) based on 100 parts by weight of the binder resin of the toner.

In a dry toner production method in which a mixture containing a binder resin, a colorant and a wax is melt-kneaded, cooled, pulverized, and classified to obtain toner particles,
It is preferable to use 1 to 10 parts by weight, more preferably 2 to 7 parts by weight, based on 100 parts by weight of the binder resin.

In a polymerization method in which toner particles are directly obtained by polymerizing a mixture containing a polymerizable monomer, a colorant and a wax, the polymerizable monomer 1
2 to 40 parts by weight, more preferably 5 to 100 parts by weight
It is preferable to use 30 parts by weight, more preferably 10 to 20 parts by weight.

Polymerization method compared to dry toner production method In a toner production method, a generally used release agent is lower in polarity than a binder resin. Therefore, in a polymerization method in an aqueous medium, a large amount of a release agent is encapsulated inside toner particles. In general, a large amount of a release agent can be used as compared with a dry toner production method, which is particularly effective in preventing an offset during fixing.

If the addition amount is less than the lower limit, the offset prevention effect tends to decrease, and if it exceeds the upper limit, the anti-blocking effect is reduced and the anti-offset effect is liable to be adversely affected. Further, in the case of a polymerization toner, a toner having a wide particle size distribution tends to be generated.

In order to obtain a sufficiently transparent OHP image with a low heat capacity of the fixing device, it is most important to lower the crystallinity of the release agent usually contained in the toner. However, in order to impart more sufficient transparency as a secondary effect, there are some undissolved toner grain boundaries that were not dissolved even after fixing, or the crystallinity of the release agent layer is caused by irregular reflection of light. In addition, the effective light transmittance is reduced, resulting in a reduction in haze. Further, even if the components mixed in the toner are sufficiently dissolved at the time of fixing, if the difference in the refractive index between the dissolved toner layer and the release agent layer formed between the fixing members is large, this is also the case of light. It is not preferable because it causes irregular reflection.

An increase in the irregular reflection of light leads to a decrease in the brightness of the projected image and a decrease in the sharpness of the color. In particular, when a transmission type overhead projector is used, this problem is further increased than when a reflection type overhead projector is used.

That is, in order to lower the crystallinity of the release agent, it is important to lower the crystallinity of the release agent alone. Further, in order to prevent unmelted toner grain boundaries from being present in the toner fixing layer, the glass transition temperature (T
A material having a small melting enthalpy (ΔH), which is the latent heat of the release agent, is particularly preferable in order to make g) and the melting point (mp) of the release agent as close as possible and to quickly dissolve it with a low energy amount. In addition, it is preferable to appropriately adjust the difference in solubility parameter (SP) between the binder resin and the release agent in order that the molten release layer quickly moves between the binder resin layer and the fixing member to form an anti-offset layer. .

Preferred examples of the present invention from such a viewpoint will be described in detail below.

In the wax used in the present invention, a polyester resin, a styrene-acrylic resin, an epoxy resin, or a styrene-butadiene resin is often used as a binder resin for the toner. Those having similar rates are preferred. As a method of measuring the refractive index, first, a solid sample having a size of vertical (20 to 30) × horizontal (8) × thickness (3 to 10) is prepared, and then the adhesion to the prism surface is improved. For this purpose, a method of measuring a refractive index by placing a small amount of bromonaphthalene on a prism surface and placing a solid sample on the prism surface is exemplified. Further, as the measuring instrument, for example, an Appe refractometer 2T manufactured by Atago Co., Ltd. may be mentioned.

The difference between the refractive indices of the binder resin and the wax at a temperature of 25 ° C. is 0.18 or less, more preferably 0.18 or less.
A value of 10 or less is particularly effective. If the difference in refractive index exceeds 0.18, the transparency of the OHP image is likely to be reduced, and a halftone projected image is not preferable because the brightness becomes low.

The melting point of the wax used in the present invention is 3
The temperature is preferably 0 to 150 ° C, more preferably 5 to 150 ° C.
0-120 ° C is particularly preferred. When the melting point is lower than 30 ° C., the blocking resistance of the toner, the suppression of sleeve contamination and the prevention of contamination of the photoreceptor during copying of a large number of sheets are apt to be reduced.
When the melting point is higher than 150 ° C., excessive energy is required for uniform mixing with the binder resin in the production method of the toner by the pulverization method. On the other hand, in the production method of the toner by the polymerization method, the homogenization into the binder resin is required. However, since the size of the apparatus is increased due to an increase in viscosity or the amount of compatibility is limited, it is not preferable because it is difficult to incorporate a large amount of the apparatus.

The solubility parameter (SP) value is determined by the method of Fedors using the additive properties of atomic groups [Polym.
Eng. Sci. , 14 (2) 147 (1974)].

The SP value of the wax used in the present invention is:
It is preferably in the range of 7.5 to 9.7. A wax having an SP value of less than 7.5 has poor compatibility with the binder resin to be used, and as a result, it is difficult to obtain a good dispersion in the binder resin. Adhesion tends to occur, and the charge amount of the toner tends to change. Further, the density fluctuates easily at the time of ground fog and toner supply. When a wax having an SP value exceeding 9.7 is used, blocking between toners is likely to occur when the toner is stored for a long period of time. Further, since the compatibility with the binder resin is too good, it is difficult to form a sufficient releasable layer between the fixing member and the toner binder resin layer at the time of fixing, and the offset phenomenon is easily caused.

The melt viscosity of the wax used in the present invention can be measured by using a cone plate type rotor (PK-1) with VT-500 manufactured by HAAKE. Melt viscosity at 100 ° C is 1 to 50 mPas · s
ec, more preferably 3 to 30 m
A wax compound having Pas · sec is particularly preferred. When the melt viscosity is lower than 1 mPas · sec, when a thin layer of the toner layer is coated on the sleeve with a blade or the like in a non-magnetic one-component developing system, the sleeve is easily contaminated by mechanical shearing force. Further, in the two-component developing method, when a toner is developed using a carrier, damage is apt to occur due to a shear force between the toner and the carrier, and burying of an external additive and crushing of the toner are likely to occur. 50
When having a melt viscosity exceeding mPas · sec,
When producing a toner using a polymerization method, the viscosity of the dispersoid is too high, and it is not easy to obtain a toner having a fine particle diameter having a uniform particle diameter, and the toner tends to have a wide particle size distribution.

The measurement of the hardness of the wax includes, for example, a measuring method using a Shimadzu Dynamic Ultra Micro Hardness Tester (DUH-200). The measurement was performed using a Vickers indenter.
10 μm at a load speed of 9.67 mg / sec under a load of 5 g
After displacing, the sample is held for 15 seconds, and a Vickers hardness is determined by analyzing a dent made on the sample. As a sample, a sample previously melted using a mold having a diameter of 20 mmφ is molded into a column having a thickness of 5 mm. The hardness of the release agent used in the present invention is preferably in the range of 0.3 to 5.0,
More preferably, the Vickers hardness is particularly preferably 0.5 to 3.0.

A toner containing a wax having a Vickers hardness lower than 0.3 is liable to be crushed at a cleaning portion of a copying machine in copying a large number of sheets, easily causing toner fusion on a drum surface, and consequently causing black streaks on an image. Is easy to occur. Further, when multiple image samples are stored while being stacked, toner is transferred to the back surface, so-called show-through tends to occur, which is not preferable. A toner containing a wax having a Vickers hardness of more than 5.0 requires an unnecessarily high pressurizing force for a fixing device used at the time of heat fixing, and requires an unnecessarily high strength design for the fixing device. If a fixing device with a normal pressing force is used, the offset resistance tends to decrease, which is not preferable.

The crystallinity of the wax is preferably 10 to 50%, more preferably 20 to 35%.

When the crystallinity is less than 10%, the toner storability and fluidity tend to deteriorate, and when it exceeds 50%, the transparency of the OHP image tends to deteriorate.

The crystallinity in the present invention is measured by the following formula from the area ratio between the amorphous scattering peak and the crystal scattering peak without using a calibration curve.

[0062]

(Equation 1)

As a measuring device, for example, Rotorflex RU300 (Cu target, point focus, output 50 KV / 250 mA) manufactured by Rigaku Corporation can be mentioned. The measurement method used the transmission method-rotation method, and the measurement angle was 2θ.
= 5 to 35 °.

As a method for producing a wax preferably used in the present invention, for example, a synthesis method by an oxidation reaction, a synthesis from a carboxylic acid and a derivative thereof, an ester group introduction reaction represented by a Michael addition reaction, and the like are used. A particularly preferred method for producing the wax used in the present invention is a method using a dehydration condensation reaction from a carboxylic acid compound and an alcohol compound or a reaction from an acid halide and an alcohol compound from the variety of raw materials and ease of reaction. preferable.

[0065]

(Equation 2)

In order to transfer the above ester equilibrium reaction to the production system, the reaction is carried out using a large excess of alcohol or in a Dean-Stark water separator in an aromatic organic solvent capable of azeotropic distillation with water. . Further, a method of synthesizing polyester by adding a base as an acceptor of an acid produced as a by-product in an aromatic organic solvent using an acid halide compound can also be used.

As the binder resin used in the toner of the present invention, the following binder resins can be used.

For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the substituted products thereof; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene Copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer; polyvinyl chloride, phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin , Xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin and the like can be used. Preferred binders include styrene copolymers or polyester resins.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Double such as dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a bond or a substituted product thereof;
For example, dicarboxylic acids having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like;
Vinyl esters such as vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene, butylene; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl methyl ether and vinyl Vinyl monomers such as ethyl ether, vinyl isobutyl ether and the like; and vinyl monomers such as one or two or more are used.

The number average molecular weight of the THF-soluble component of the binder resin of the present invention is preferably from 3,000 to 1,000,000.

The styrene-based polymer or styrene-based copolymer may be crosslinked, or may be a resin mixture thereof.

As the crosslinking agent for the binder resin, a compound having mainly two or more polymerizable double bonds may be used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butadiol dimethacrylate; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and 3
Compounds having at least two vinyl groups are used alone or as a mixture. The amount of the polymerizable monomer 1
0.001 to 10 parts by weight based on 00 parts by weight is preferred.

The toner of the present invention may contain a charge control agent.

The following substances control the toner to be negatively charged.

For example, organic metal compounds and chelate compounds are effective, and examples thereof include monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid-based metal compounds. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

Also, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarenes, silicon compounds,
A styrene-acrylic acid copolymer, a styrene-methacrylic acid copolymer, a styrene-acryl-sulfonic acid copolymer, a non-metal carboxylic acid compound, and the like can be given.

The following substances control the toner to be positively charged.

Modified products such as nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like; Onium salts such as phosphonium salts, which are analogs, and their lake pigments, triphenylmethane dyes and these lake pigments (phosphor tungstic acid,
Phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide,
Ferrocyanide), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate and dicyclohexyltin borate; Alternatively, two or more kinds can be used in combination. Among these, nigrosine,
A charge control agent such as a quaternary ammonium salt is particularly preferably used.

These charge control agents are preferably used in an amount of 0.01 to 20 parts by weight (more preferably 0.5 to 10 parts by weight) based on 100 parts by weight of the resin component.

As the colorant used in the present invention, a black colorant prepared by using carbon black, a magnetic substance, and a yellow / magenta / cyan colorant shown below is used.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168, 180 and the like are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8; 2, 48; 3, 48; 4, 57; 1, 81; 1, 1
44, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221, 254 are particularly preferred.

As the cyan colorant used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used.
Specifically, C.I. I. Pigment Blue 1, 7, 15,
15: 1, 15: 2, 15: 3, 15: 4, 60, 6
2, 66 and the like can be particularly preferably used. These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in toner. The amount of the coloring agent is 1 to 100 parts by weight of the resin.
Used in an amount of up to 20 parts by weight.

Further, the toner of the present invention can be used as a magnetic toner by further containing a magnetic material. In this case, the magnetic material can also serve as a colorant. In the present invention, the magnetic material contained in the magnetic toner includes iron oxides such as magnetite, hematite, and ferrite;
Metals such as cobalt and nickel or metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium Alloys and mixtures thereof.

The magnetic material used in the present invention is more preferably a surface-modified magnetic material. When the magnetic material is used in a polymerization toner, the magnetic material is hydrophobically treated with a surface modifier which is a substance having no polymerization inhibition. Any surface modifier may be used as long as it is subjected to a chemical conversion treatment. Examples of such a surface modifier include a silane coupling agent and a titanium coupling agent.

These ferromagnetic materials preferably have an average particle size of 2 μm or less, preferably about 0.1 to 0.5 μm. The amount contained in the toner is preferably about 20 to 200 parts by weight, particularly preferably 40 to 150 parts by weight, per 100 parts by weight of the resin component.

The magnetic characteristics at 10 K Oe applied are as follows: the coercive force (Hc) is 20 to 300 Oe, the saturation magnetization (σs) is 50 to 200 emu / g, and the residual magnetization (σ)
r) Those having 2 to 20 emu / g are preferred.

The additive for imparting various toner properties should have a particle diameter of 1/5 or less of the volume average diameter of the toner particles in view of the durability when added to the toner or when added to the toner. Is preferred. The particle size of the additive means an average particle size obtained by observing the surface of the toner particles with an electron microscope. As additives for imparting these properties, for example, the following are used.

Examples of the fluidity-imparting agent include metal oxides (such as silicon oxide, aluminum oxide, and titanium oxide), carbon black, and carbon fluoride. Those subjected to a hydrophobic treatment are more preferable.

Examples of the abrasive include metal oxides (such as strontium titanate, cerium oxide, aluminum oxide, magnesium oxide and chromium oxide), nitrides (such as silicon nitride), carbides (such as silicon carbide), and metal salts (calcium sulfate). , Barium sulfate, calcium carbonate, etc.).

Examples of the lubricant include fluororesin powder (vinylidene fluoride, polytetrafluoroethylene, etc.) and fatty acid metal salts (zinc stearate, calcium stearate, etc.).

Examples of the charge control particles include metal oxides (such as tin oxide, titanium oxide, zinc oxide, silicon oxide, and aluminum oxide) and carbon black.

These additives are used in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of the toner particles.
1 to 5 parts by weight are used. These additives may be used alone or in combination of two or more.

The toner of the present invention can be used as a one-component or two-component developer in any developer.

For example, in the case of a magnetic toner in which a magnetic substance is contained in a toner as a one-component developer, there is a method of using a magnet built in a developing sleeve to transport and charge the magnetic toner. . When a non-magnetic toner containing no magnetic substance is used, there is a method in which the toner is conveyed by forcibly frictionally charging the developing sleeve with a blade and a fur brush and causing the toner to adhere to the sleeve.

On the other hand, when used as a generally used two-component developer, a carrier is used as a developer together with the toner of the present invention. The carrier used in the present invention is not particularly limited, but is mainly composed of a single ferrite and a composite ferrite composed of iron, copper, zinc, nickel, cobalt, manganese, and chromium. The carrier shape is also important because saturation magnetization and electric resistance can be controlled in a wide range. For example, it is preferable to select a spherical shape, a flat shape, an irregular shape, and the like, and to further control the fine structure of the carrier surface state, for example, the surface unevenness. . Generally, the above inorganic oxide is calcined,
A method of coating the resin after forming carrier core particles in advance by granulation is used.However, from the viewpoint of reducing the load on the toner of the carrier, the inorganic oxide and the resin are kneaded and then pulverized. , A method of obtaining a low-density dispersion carrier by classification, and a method of directly obtaining a polymerized carrier for obtaining a spherical dispersion carrier by suspension-polymerizing a kneaded product of an inorganic oxide and a monomer in an aqueous medium are also used. It is possible to

A system in which the surface of the carrier is coated with a resin or the like is particularly preferable. As the method, any conventionally known method such as a method of dissolving or suspending a coating material such as a resin in a solvent, coating and adhering to a carrier, and a method of simply mixing with a powder can be applied.

The substance to be fixed to the carrier surface varies depending on the toner material. Examples thereof include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, metal compound of ditersharry butylsalicylic acid, and styrene-based compounds. It is appropriate to use resin, acrylic resin, polyamide, polyvinyl butyral, nigrosine, aminoacrylate resin, basic dye and its lake, silica fine powder, alumina fine powder, etc. alone or in combination, but it is not necessarily limited to this. Not done.

The treatment amount of the above compound is generally preferably 0.1 to 30% by weight (preferably 0.5 to 20% by weight) based on the total amount of the carrier of the present invention.

The average particle size of these carriers is 10 to 100.
μm, preferably 20 to 50 μm.

A particularly preferred embodiment is ferrite, whose surface is a combination of a resin such as a fluorine resin and a styrene resin, for example, polyvinylidene fluoride and styrene-methyl methacrylate resin; polytetrafluoroethylene and styrene-methyl methacrylate resin. 90: 1 acrylate resin, fluorine-based copolymer and styrene-based copolymer;
A mixture having a ratio of 0 to 20:80, preferably 70:30 to 30:70, or a silicone resin or the like, 0.01 to 5% by weight, preferably 0.1 to 3% by weight.
Coated and coated ferrite carriers. As the fluorine-based copolymer, a vinylidene fluoride-tetrafluoroethylene copolymer (10:90
To 90:10), and styrene-based copolymers such as styrene-2-ethylhexyl acrylate (20: 8
0-80: 20), styrene-2-ethylhexyl acrylate-methyl methacrylate (20-60: 5-30:
10 to 50).

The coated ferrite carrier has a sharp particle size distribution, provides favorable triboelectrification to the toner of the present invention, and has the effect of improving electrophotographic properties.

When a two-component developer is prepared by mixing with the toner of the present invention, the mixing ratio is 2 to 15% by weight, preferably 4 to 13% by weight, as the toner concentration in the developer. % Usually gives good results. If the toner density is less than 2%, the image density is low, making it impractical. If the toner density is more than 15%, fog and scattering inside the machine are increased, and the useful life of the developer is shortened.

Further, the magnetic properties of the carrier are preferably as follows. The saturation magnetization needs to be ^{20 to} 90 Am2 / kg. To achieve higher image quality,
Preferably, it is 30 to 70 Am ² / kg. If it is larger than 90 Am ² / kg, it becomes difficult to obtain a high quality toner image. If it is less than 20 Am ² / kg, carrier adhesion is likely to occur because the magnetic binding force is reduced.

The method for producing the pulverized toner in the present invention includes a binder resin, the above-mentioned ester wax of the present invention, a pigment or dye as a colorant, a magnetic substance, a charge control agent if necessary,
While the other additives, etc. are thoroughly mixed by a mixer such as a Henschel mixer, a ball mill, and then melt-kneaded using a heat kneader such as a heating roll, a kneader, or an extruder to make the resins compatible with each other. The toner according to the present invention can be obtained by dispersing or dissolving a metal compound, a pigment, a dye, and a magnetic substance, and performing cooling and solidification followed by pulverization and classification.

Further, if necessary, desired additives are sufficiently mixed by a mixer such as a Henschel mixer to obtain the electrostatic image developing toner according to the present invention.

The method for producing the polymerized toner used in the present invention includes a method described in JP-B-56-13945 and the like, in which a molten mixture is atomized into air using a disk or a multi-fluid nozzle to obtain a spherical toner. JP-B-36-10231, JP-A-59-53856, and JP-A-59-6.
No. 1842, a method of directly producing a toner by using a suspension polymerization method, and a method of dispersing by directly producing a toner by using an aqueous organic solvent which is soluble in a monomer and insoluble in a polymer obtained. Emulsion polymerization method represented by soap-free polymerization method, which produces a toner by directly polymerizing in the presence of a legal or water-soluble polar polymerization initiator, or after preparing primary polar emulsion polymerization particles in advance,
It is possible to produce a toner using a heteroaggregation method or the like in which polar particles having opposite charges are added and associated.

However, in the dispersion polymerization method, the obtained toner shows an extremely sharp particle size distribution, but the selection of materials to be used is narrow, and the use of an organic solvent has an effect on waste solvent treatment and solvent flammability. From the viewpoint, the manufacturing apparatus is complicated and complicated. The emulsion polymerization method represented by soap-free polymerization is effective because the particle size distribution of the toner is relatively uniform, but when the used emulsifier and initiator terminal are present on the surface of the toner particles, the environmental characteristics are likely to deteriorate.

In the present invention, a suspension polymerization method under normal pressure or under pressure, which can easily obtain a fine particle toner having a sharp particle size distribution, is particularly preferable. A so-called seed polymerization method in which a monomer is further adsorbed on the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention.

A more preferable toner used in the present invention is produced by a direct polymerization method in which a wax is particularly encapsulated in a shell resin layer by a tomographic plane measurement method using a transmission electron microscope (TEM). It is a thing. From the viewpoint of fixing property, it is necessary to incorporate a large amount of wax into the toner, so that it is necessary to incorporate necessary wax into the outer shell resin. Unless the toner is not encapsulated, the toner cannot be sufficiently pulverized unless a special freeze-pulverization is used in the pulverization process, resulting in only a toner having a wide particle size distribution. This is extremely undesirable. In the freezing and pulverization, the device becomes complicated to prevent dew condensation on the device, and if the toner absorbs moisture, the workability of the toner is reduced, and it is necessary to further add a drying process. Become. As a specific method of encapsulating the wax, the polarity of the material in the aqueous medium is set to be smaller for the wax than for the main monomer, and a small amount of a polar resin or monomer is further added. A toner having a so-called core-shell structure in which wax is coated with an outer shell resin can be obtained. To control the particle size distribution and the particle size of the toner, methods such as changing the type and amount of the dispersant that acts as a poorly water-soluble inorganic salt or protective colloid, and mechanical device conditions such as the peripheral speed of the rotor, the number of passes, and the stirring blades The predetermined toner of the present invention can be obtained by controlling the stirring conditions such as the shape, the shape of the container, and the solid content concentration in the aqueous solution.

As a specific method for measuring the tomographic plane of the toner in the present invention, the toner can be obtained by sufficiently dispersing the toner in an epoxy resin which is curable at room temperature and then curing it in an atmosphere at a temperature of 40 ° C. for 2 days. The cured product is stained with ruthenium tetroxide and, if necessary, osmium tetroxide, and then sliced using a microtome with diamond teeth, and cut out using a transmission electron microscope (TEM). Was measured. In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to give a contrast between materials by utilizing a slight difference in crystallinity between the wax used and the resin constituting the outer shell.

When a direct polymerization method is used in the toner production method of the present invention, the toner can be specifically produced by the following production method. A wax, a coloring agent, a charge control agent, a polymerization initiator and other additives are added to the monomer, and a monomer system uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser or the like, and a dispersion stabilizer is contained. Disperse in the aqueous phase using a conventional stirrer, homomixer, homogenizer or the like. Preferably, the stirring speed and time are adjusted so that the monomer droplets have the desired size of the toner particles, and the granulation is performed. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. Further, the temperature may be increased in the latter half of the polymerization reaction, and further, unreacted polymerizable monomers that cause odor at the time of fixing the toner,
In order to remove by-products and the like, a part of the aqueous medium may be distilled off in the latter half of the reaction or after completion of the reaction. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried.
In the suspension polymerization method, it is generally preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer system.

When a toner is directly obtained by a polymerization method, styrene, o (m-, p-
Styrene-based monomers such as-)-methylstyrene, m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dimethyl (meth) acrylate (Meth) acrylate monomers such as aminoethyl and diethylaminoethyl (meth) acrylate; and ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide are preferably used.

In the present invention, in order to form a core-shell structure, it is essential to use a polar resin in combination. Polar polymers and copolymers usable in the present invention are exemplified below.

Polymers of nitrogen-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, copolymers with styrene-unsaturated carboxylic acid esters and the like, nitrile monomers such as acrylonitrile, and vinyl chloride and the like Halogen-containing monomers, acrylic acid, unsaturated carboxylic acids such as methacrylic acid, and other unsaturated dibasic acids,
Unsaturated dibasic acid anhydrides, polymers such as nitro monomers or copolymers with styrene monomers, polyesters,
Epoxy resins and the like can be mentioned. More preferred are a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin.

Examples of the polymerization initiator include, for example, 2,2′-
Azobis- (2,4-dimethylvaleronitrile), 2,
2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2 ′
Azo or diazo polymerization initiators such as azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butylhydro Peroxide, di-t-butyl peroxide, dixyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis (4,
4-tert-butylperoxycyclohexyl) propane,
A peroxide initiator such as tris- (t-butylperoxy) triazine, a polymer initiator having a peroxide in a side chain, a persulfate such as potassium persulfate and ammonium persulfate, and hydrogen peroxide are used. You.

The polymerization initiator is 0.5 to 20 of the polymerizable monomer.
The addition amount by weight is preferable, and it may be used alone or in combination.

In the present invention, in order to control the molecular weight, a known crosslinking agent or chain transfer agent may be added, and a preferable addition amount is 0.001 to 15 parts by weight.

In the present invention, any suitable stable medium may be used as a dispersion medium for producing a polymerization toner by emulsion polymerization, dispersion polymerization, suspension polymerization, seed polymerization, polymerization using a heteroaggregation method, or the like. Use agent. For example, as inorganic compounds, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like. As organic compounds, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and salts thereof, starch, polyacrylamide, polyethylene oxide, poly (hydroxystearic acid-g-methacrylic acid) A methyl-eu-methacrylic acid) copolymer or a nonionic or ionic surfactant is used.

When the emulsion polymerization method and the hetero-aggregation method are used, an anionic surfactant, a cationic surfactant, an amphoteric surfactant and a nonionic surfactant are used. It is preferable to use 0.2 to 30 parts by weight of these stabilizers based on 100 parts by weight of the polymerizable monomer.

When an inorganic compound is used among these stabilizers, a commercially available one may be used as it is, but in order to obtain fine particles, the inorganic compound may be formed in a dispersion medium.

For finely dispersing these stabilizers, 0.001 to 0.1 parts by weight of a surfactant may be used. This is to promote the intended action of the dispersion stabilizer, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate,
Examples include sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like.

In the present invention, it is necessary to pay attention to the polymerization inhibitory property and the water phase migration property of the colorant used in the polymerization toner in the present invention. It is better to perform a hydrophobic treatment without inhibiting polymerization. In particular, many dyes and carbon blacks have polymerization inhibitory properties, so care must be taken when using them. As a preferable method for surface-treating the dye system, a method in which a polymerizable monomer is previously polymerized in the presence of these dyes is mentioned, and the obtained colored polymer is added to the monomer system. The carbon black may be treated with a substance that reacts with the surface functional group of the carbon black, for example, a polyorganosiloxane, in addition to the same treatment as the above dye.

Next, a fixing device suitable for the present invention will be described.

FIG. 1 schematically shows a film heating type apparatus (image heating fixing apparatus). Numeral 11 is a general code. 2
Reference numeral 4 denotes a heat-resistant fixing film in the form of an endless belt as a pressure contact member, which is a low driving roller 25 on the left side, a driven roller 26 on the right side, and a low heating element disposed between the driving roller 25 and the driven roller 26. The calorimetric linear heating element 20 is suspended between the three parallel members 25, 26, 20. Reference numeral 10 denotes a cleaning pad for removing residual toner on the fixing film 24.

The driven roller 26 also serves as a tension roller for the endless belt-shaped fixing film 24. The fixing film 24 is rotated at a predetermined peripheral speed in the clockwise direction by the clockwise rotation of the driving roller 25, that is, not shown. Wrinkles, meanders, and speed delays at the same peripheral speed as the transfer speed (105 mm / sec in this example) of the transfer material sheet P as a recording material carrying the unfixed toner image Ta conveyed from the image forming unit on the upper surface. It rotates without being driven.

Reference numeral 28 denotes a pressure roller having a rubber elastic body having good releasability, such as silicone rubber, as a pressure member. The pressure roller 28 is opposed to the endless belt-shaped fixing film 24, and is pressed, for example, at a linear pressure of 1 kg / cm by an urging means (not shown) on the lower surface of the heating body 20.
And the transfer material sheet P
Rotates counterclockwise in the forward direction in the transport direction. The pressure roller 28 has an outer diameter of 30 mm, which is formed concentrically and integrally with the outer periphery of the cored bar by die molding, has an elastic layer in the base layer, and has a specific flexural modulus in the outermost layer. FE with
There is a resin layer such as P, PFA, etc., and a fluorine rubber layer having a hardness higher than that of the elastic layer of the base layer is formed between the base layer and the surface layer.
It is an elastic roller provided at 10 μm.

The heating element 20 is a low-heat-capacity linear heating element whose longitudinal direction is the direction intersecting with the plane movement direction of the fixing film 24 (the width direction of the film). , A temperature measuring element 23, etc., which are attached to and held by the heater support 27 and fixedly supported.

The heater support 27 thermally supports the heater 20 with respect to the fixing device 11 and the entire image forming apparatus in which the fixing device is incorporated.

The heater substrate 21 is a member having heat resistance, insulation, low heat capacity, and high heat conductivity.
It is an alumina substrate having a length of 10 mm and a width of 310 mm.

In the case of the heating element 20 of this example, the heating element 22 having a linear or a band shape is energized from both ends in the longitudinal direction to generate heat over substantially the entire length.
The energization is AC100V, and the energization power is controlled by controlling the phase angle by an unillustrated energization control circuit including a triac according to the temperature detected by the temperature detecting element 23.
The fixing temperature is controlled to be 180 ° C.

The surface resistance of the fixing film 24 is preferably 10 ¹⁰ Ω or less. The surface resistance can be reduced by kneading a conductive material such as carbon black, graphite, and conductive whiskers.

As still another preferred embodiment, a heat-resistant film or belt member having a conductive layer and a pressing member having a conductive layer, and an eddy current generated by applying a magnetic field to these conductive layers to generate heat. And a heating device for heating the material to be heated by sandwiching and conveying the material to be heated in the nip portion between the heat-resistant member and the pressing member.

[0134]

Example 1 450 g of a 0.1 M Na ₃ PO ₄ aqueous solution was charged into 710 g of ion-exchanged water, heated to 60 ° C., and then, using a TK homomixer (manufactured by Tokushu Kika Kogyo). The mixture was stirred at 1300 rpm. 68 g of 1.0 M CaCl ₂ aqueous solution
Was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ . On the other hand, styrene 166 g n-butyl acrylate 34 g copper phthalocyanine pigment 15 g ditertiary-butyl salicylic acid metal compound 3 g saturated polyester 10 g (acid value 11, peak molecular weight 8500) monoester wax 40 g (Mw 500, Mn 400, viscosity 6.5 mPa · s, SP value) 8.6)

The above-mentioned formulation was heated to 60 ° C., and was subjected to 12000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
To dissolve and disperse uniformly. In addition, polymerization initiator 2,
2'-azobis (2,4-dimethylvaleronitrile) 1
0 g was dissolved to prepare a polymerizable monomer composition. The polymerizable monomer composition was charged into the aqueous medium,
Under N ₂ atmosphere, use a TK homomixer for 100
The mixture was stirred at 00 rpm for 20 minutes to granulate the polymerizable monomer composition. Thereafter, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C., and the reaction was performed for 10 hours.

After the completion of the polymerization reaction, the mixture was cooled, hydrochloric acid was added to dissolve calcium phosphate, and then filtered, washed with water and dried to obtain polymer particles.

With respect to 100 parts by weight of the obtained particles, BE
2.0 parts by weight of hydrophobic titanium oxide having a specific surface area of 100 m ² / g by the T method was externally added to obtain a toner having an average particle diameter of 6.2 μm.

To 7 parts by weight of this toner, 93 parts by weight of a 35 μm silicone-coated ferrite carrier were mixed, and developer No. 1 was added. It was set to 1.

Using this developer, a commercially available full-color copying machine CLC800 (manufactured by Canon Inc.) was modified and a film heating system was installed as shown in FIG.

Here, the following were used as the fixing film and the pressure roller.

(1) Fixing film Base sheet: polyimide resin, thickness 20 μm Elastic layer: silicone rubber, thermal conductivity D = 2 × 10 ⁻³
cal / cm · sec · ° C., thickness T = 2 mm · Surface layer: FEP resin, flexural modulus A = 6000 kgf
/ Cm ² , surface hardness (Hs) C = 70 degrees, thickness = 20μ (2) Pressure roller ・ Core metal: Al (40 mmφ) ・ Elastic layer: silicone rubber, thickness = 1 mm ・ Surface layer: FEP resin , Flexural modulus B = 6000 kgf
/ Cm ² , surface hardness (Hs) C = 70 degrees, thickness = 20 μ The linear pressure E at the time of pressing the fixing film and the pressure roller is 1.0 kg / cm, and the nip (width 5 mm) is approximately It is formed flat.

As the FEP resin of the surface layer, NEOFLON ND1 manufactured by Daikin Industries, Ltd. was used.
It was baked at 0 ° C. for 30 minutes. Between the surface layer and the base layer, a fluorine rubber layer having a hardness higher than that of the elastic layer
-10 μm was used.

Using two types of original manuscripts having a resolution image area of 20% and 50%, a pass-through test of 10,000 sheets was performed. Table 1 shows the results together with the transparency of OHP.

Comparative Example 1 In Example 1, a paraffin wax (Mw 470, Mn 380, viscosity: 6.8) was used in place of the monoester wax.
mPa · s, SP value 8.3), except that developer No. 2 was produced.

The surface hardness of the fixing film (H
The evaluation was performed using the same apparatus as in Example 1 except that s) was 95 degrees and the surface hardness of the pressure roller was 70 degrees. The results are shown in Table 1. It is presumed that the surface hardness at this time was large and minute gloss unevenness occurred.

Comparative Example 2 Evaluation was made in the same manner as in Example 1 except that the linear pressure E was 0.5 kg / cm, but no satisfactory result was obtained. This is presumably because the linear pressure was inappropriate.

Comparative Example 3 In Example 1, ETFE resin (tetrafluoroethylene-ethylene copolymer) was used as the surface resin, and the flexural modulus of the surface resin at 23 ° C. was 11,000 kgf / cm.
Except a ^2, it was evaluated in the same manner as in Example 1, satisfactory results were not obtained. This is presumably because the flexural modulus of the surface resin at 23 ° C. was inappropriate.

Example 2 The following were used as the fixing film and the pressure roller.

(1) Fixing film Base sheet: polyimide resin, thickness 20 μm Elastic layer: silicone rubber, thermal conductivity D = 1.5 × 1
0 ⁻³ cal / cm · sec · ° C., thickness T = 0.5 mm Surface layer: PFA resin, flexural modulus A = 6800 kgf
/ Cm ² , surface hardness (Hs) C = 60 degrees, thickness = 15μ (2) Pressure roller ・ Core metal: Al (40 mmφ) ・ Elastic layer: silicone rubber, thickness = 3 mm ・ Surface layer: PFA resin , Flexural modulus B = 6800kgf
/ Cm ² , surface hardness (Hs) C = 80 degrees, thickness = 10 μ The linear pressure E when pressing the fixing film and the pressure roller is 2.0 kg / cm, and the nip (width 6 mm) is substantially It is formed flat.

For the PFA resin of the surface layer, NEOFLON AD-2CR manufactured by Daikin Industries, Ltd. was used.
It baked for 30 minutes at -400 degreeC. Between the surface layer and the base layer, a fluororubber layer having a hardness higher than that of the elastic layer was used as a primer. When image formation was performed in the same manner as in Example 1, good results were obtained.

Example 3 In Example 1, diester wax (Mw 480, Mn 410, viscosity: 10) was used in place of the monoester wax.
5 mPa · s, SP value 9.1) except that developer No. 3 was produced.

Here, the following were used as the fixing film and the pressure roller.

(1) Fixing film Base sheet: polyimide resin, thickness 20 μm Elastic layer: silicone rubber, thermal conductivity D = 2 × 10 ⁻³
cal / cm · sec · ° C., thickness T = 0.5 mm Surface layer: FEP resin + PFA resin (weight ratio 8: 2),
Flexural modulus A = 4000 kgf / cm ² , surface hardness (H
s) C = 65 degrees, thickness = 20μ (2) Pressure roller ・ Core metal: Al (40 mmφ) ・ Elastic layer: silicone rubber, thickness = 1 mm ・ Surface layer: FEP resin + PFA resin (weight ratio: 8: 2),
Flexural modulus B = 4000 kgf / cm ² , surface hardness (H
s) C = 80 degrees, thickness = 20 μ The linear pressure E at the time of pressing the fixing film and the pressure roller is 1.5 kg / cm, and the nip (width) is formed substantially flat.

The FEP resin and PFA resin of the surface layer were mixed with the resins of Examples 1 and 2 and used at 380 ° C. to 40 ° C.
It was baked at 0 ° C. for 30 minutes. Between the surface layer and the base layer, a fluorine rubber layer having a hardness higher than that of the elastic layer
-10 μm was used.

When image formation was performed in the same manner as in Example 1,
Good results were obtained.

Example 4 In Example 1, a tetraester wax (Mw430, Mn380, Mw8) was used instead of the monoester wax.
50 with shoulder, viscosity 11.6mPa · s, SP
Value 8.5), except that developer No. 8.5) was used. 4
Was prepared.

The following were used as the fixing film and the pressure roller.

(1) Fixing film Base sheet: polyimide resin, thickness 20 μm Elastic layer: silicone rubber, thermal conductivity D = 1 × 10 ⁻³
cal / cm · sec · ° C., thickness T = 0.5 mm Surface layer: FEP resin + PFA resin (weight ratio 6: 4),
Flexural modulus A = 5000 kgf / cm ² , surface hardness (H
s) C = 40 degrees, thickness = 15μ (2) Pressure roller ・ Core metal: Al (40 mmφ) ・ Elastic layer: silicone rubber, thickness = 0.5 mm ・ Surface layer: FEP resin + PFA resin (weight ratio) 6: 4),
Flexural modulus B = 5000 kgf / cm ² , surface hardness (H
s) C = 40 degrees, thickness = 20 μ The linear pressure E at the time of pressing the fixing film and the pressure roller was 0.8 kg / cm, and the nip (width 4.5 m) was used.
m) is formed substantially flat.

The FEP resin and PFA resin of the surface layer were mixed with the resins of Examples 1 and 2 and used at 380 ° C. to 40 ° C.
It was baked at 0 ° C. for 30 minutes. Between the surface layer and the base layer, a fluorine rubber layer having a hardness higher than that of the elastic layer
-10 μm was used.

When image formation was performed in the same manner as in Example 1,
Good results were obtained.

Example 5 The following were used as the fixing film and the pressure roller.

(1) Fixing film Base sheet: polyimide resin, thickness 20 μm Elastic layer: silicone rubber, thermal conductivity D = 2 × 10 ⁻³
cal / cm · sec · ° C., thickness T = 3 mm · Surface layer: FEP resin, flexural modulus A = 6000 kgf
/ Cm ² , surface hardness (Hs) C = 40 degrees, thickness = 20μ (2) Pressure roller ・ Core metal: Al (40 mmφ) ・ Elastic layer: silicone rubber, thickness = 2 mm ・ Surface layer: FEP resin , Flexural modulus B = 6000 kgf
/ Cm ² , surface hardness (Hs) C = 40 degrees, thickness = 20 μ The linear pressure E at the time of pressing the fixing film and the pressure roller is 2.0 kg / cm, and the nip (width 5 mm) is approximately It is formed flat.

For the surface FEP resin, NEOFLON ND1 manufactured by Daikin Industries, Ltd. was used.
It was baked at 0 ° C. for 30 minutes. Between the surface layer and the base layer, a fluorine rubber layer having a hardness higher than that of the elastic layer
-10 μm was used.

When image formation was performed in the same manner as in Example 1,
Good results were obtained.

[0165]

[Table 1]

Example 6 In Example 1, a quinacridone pigment was used instead of the copper phthalocyanine pigment. I. Pigment Yellow 180,
Magenta, yellow, and black developers were prepared and imaged in the same manner except that carbon black was used. Light color reproduction was excellent and good results were obtained.

Example 7 A magnetic toner was obtained in the same manner as in Example 1, except that 200 g of magnetic iron oxide treated with a silane coupling agent (average particle size: 0.25 μm) was used and hydrophobic silica was used. When an image was formed using this magnetic toner, good results were obtained.

In addition to the above examples, the surface resin does not need to use the same resin for the fixing film and the pressure roller.
Of course, any combination can be selected.

[0169]

According to the present invention, when the flexural modulus of the surface resin of the pressing member and the pressing roller of the fixing device is within the above range, a part or all of the wax forms an appropriate film,
It is possible to provide an image forming apparatus which is applicable to a clear full-color OHP having excellent offset resistance and excellent transparency without causing toner offset.

Furthermore, in a film heating type apparatus,
When a full-color image is formed, there is no need to take a long cooling step after heating or separate cooling means such as a fan to separate the fixing film without offsetting the fixing film. can do.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of a film heating type fixing device.

[Explanation of symbols]

 Reference Signs List 20 heating element 24 fixing film (pressure contact member) 28 pressure roller P recording material (paper)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-34287 (JP, A) JP-A-6-295091 (JP, A) JP-A-3-54426 (JP, A) JP-A-3-34426 25478 (JP, A) JP-A-7-219365 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08-9/097 G03G 13/20 G03G 15/20

Claims (6)

(57) [Claims] An image forming apparatus in which an unfixed toner image carried on a recording material is fixed to the recording material by a fixing device that heats and / or presses with a pressure contact member, wherein the toner is formed by fixing at least the toner image. A toner containing a resin, a colorant, and a wax; and a pressure roller pressed against the pressure member so as to form a nip, wherein the pressure member surrounds a base sheet made of polyimide. An elastic body layer having heat resistance and a surface layer having releasability where the flexural modulus A (kgf / cm ² ) of the surface resin at 23 ° C. of the pressing member is 4000 ≦ A ≦ 10000. pressure roller, around the core metal, an elastic layer having heat resistance, flexural modulus of the surface layer resin in 23 ° C. of pressurizing roller B (kgf / cm ²⁾ is, 4000 ≦ B ≦ 10000 A surface layer having releasability provided, the surface hardness (Hs) of the pressing member and the pressure roller C
1 ≦ C ≦ 90, and the elastic layer of the press-contact member has a thermal conductivity D (cal / cm
.Sec. ° C.) is 0.2 × 10 ⁻³ ≦ D ≦ 2 × 10 ⁻³ , and the thickness T (mm) is 0.1 ≦ T ≦ 3. Linear pressure E when pressing against pressure roller
(Kg / cm): 0.8 ≦ E ≦ 2.0, and the nip is formed substantially flat. 2. A weight average molecular weight (Mw) of the wax.
2. The image forming apparatus according to claim 1, wherein the number is from 400 to 4000 and the number average molecular weight (Mn) is from 200 to 4000. 3. The image forming apparatus according to claim 1, wherein the pressing member has at least a repeating unit of tetrafluoroethylene in a main chain. 4. The press-contact member according to claim 1, wherein the main chain has at least a tetrafluoroethylene repeating unit in a main chain, and has a fluoroalkoxy group and / or a fluoroalkyl group in a side chain. Image forming apparatus. 5. The image forming apparatus according to claim 1, wherein the pressing member has at least a tetrafluoroethylene repeating unit in a main chain and a fluoroalkyl group in a side chain. 6. The image forming apparatus according to claim 4, wherein the fluoroalkyl group is a methyl trifluoride group.