JPH1091028A - Image forming method - Google Patents

Abstract

(57) [Problem] To provide an image forming method which is excellent in fixing property to a recording material and anti-offset property over a long period of time and can realize a high-quality full-color image excellent in transparency. SOLUTION: An image forming method for fixing an unfixed toner (T) image carried on a recording material P to the recording material by a fixing device which heats and / or presses with pressure members 101 and 102 is provided. At least the pressure contact member 1
01 is provided, and the toner is a toner containing at least a binder resin, a colorant and a wax.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method using an electrostatic image developing toner suitable for heat fixing, which is used in electrophotography, electrostatic recording, and magnetic recording.

[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. As a transfer material for fixing a toner image by 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, unlike OHP, unlike paper, since the oil absorption capacity is low, the currently obtained copy OHP is inevitably greasy due to oil application, and a large problem remains in the quality of the obtained image. In addition, there is a large possibility that silicone oil and the like will evaporate due to heat and contaminate the inside of the machine, and problems such as processing of collected oil will occur. Therefore, instead of using a silicone oil supply device, instead of supplying the anti-offset liquid during heating from the toner, a method of adding a release agent such as low molecular weight polyethylene or low molecular weight polypropylene to the toner is proposed. Have been. 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 so as not to deteriorate the image,
It has been practiced to use a device that uses a releasable oil or a device that uses a member such as a web of a take-up type, or a device that cleans the offset toner by using a cleaning pad.

However, especially 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.

Further, 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 properties of toner at low and high temperatures and to improve the fixability at low temperatures, but, on the other hand, deteriorate the anti-blocking properties and prevent the use of 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.

No conventional toner satisfies all of these aspects, causing some problems. For example, high-temperature offset 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 decreases when the temperature rises in the machine. Or the offset resistance at low and high temperatures cannot be compatible.
The transparency was extremely poor.

In particular, regarding the transparency of OHP, a proposal is made to add a crystallization nucleating agent or the like to the wax in order to reduce the crystallization of the wax itself (JP-A-4-149559 and JP-A-4-107467). Proposal of using wax having low crystallinity (Japanese Unexamined Patent Publication (Kokai) No. 3-09110)
No. 8, JP-A-3-242397) and a substance having good compatibility with a binder and having a lower melt viscosity than the binder is added to the binder to improve the surface smoothness of the toner layer after fixing. Japanese Patent Application Laid-Open No. Hei 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 a montan wax:

[0020]

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, it has been proposed to use an ester wax in which the structure of the release agent itself is broken in symmetry (Japanese Patent Laid-Open No. 5-11851).
7, JP-A-5-126180, JP-A-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 demanded, and the improvement of the binder resin and the release agent of the toner alone without the improvement of the fixing device reduces the image area from a high image area to a low image. 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.

When a toner which does not need to be coated with a release oil is used, only the portion where the toner is present is supplied to the pressing member with the wax which functions as a release agent, so that the paper powder easily adheres. The recording material is transported along the recording material transport path from the paper supply section to the transfer section and then to the fixing section.The friction between the surface of the recording material and the paper supply roller and the recording material transport roller in the recording material transport path Paper dust is generated on the recording material due to contact or frictional contact with a guide member forming a recording material conveyance path. In particular, a large amount of paper dust is generated due to the frictional contact between the recording material surface and the paper feed roller with a large friction.

Therefore, a large amount of paper dust adheres to the pressing member, and the apparent releasability of the pressing member is reduced. First, it has been confirmed that the use of a device using a member such as a web or a device using a cleaning pad for feeding a small amount of release oil or taking up offset toner is performed in combination. As described above, paper dust can be removed by this method, but paper dust accumulates at a corresponding portion of the press-contact member and acts as an abrasive to damage the press-contact member. In order to avoid this, it is conceivable to send the web before the paper dust accumulates and always maintain a new surface.However, the accumulation amount of the paper dust is not effective, and the web feed amount is increased. This leads to a significant increase in running costs.

If the paper dust cannot be removed, the paper dust accumulates on the surface of the press-contact member, and the apparent releasability remarkably deteriorates, so that a so-called offset phenomenon that causes the adhesion of the toner is caused.

A method has been proposed in which the surface of the press-contact member is made robust and the polishing is positively performed. However, it is difficult to perform the polishing uniformly, and the press-contact member may be damaged unevenly.

[0028]

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

Another object of the present invention is to provide an image forming method which is excellent in 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 method capable of fixing without applying a large amount of oil or without applying any oil.

Another object of the present invention is to provide an image forming method capable of obtaining a high-quality full-color OHP having excellent transparency.

[0032]

According to the present invention, there is provided an image forming method 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. The present invention also relates to an image forming method, comprising: at least a paper dust removing means abutting on the pressing member, wherein the toner is a toner containing at least a binder resin, a colorant and a wax.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the wax used in the present invention, any of them can be used.
It is preferable to use a low-crystalline material having a suitable affinity for the binder resin, a high hydrophobicity and a low melting point in order to develop offset resistance. Further, it is preferable that the molecular weight distribution of the wax has at least two peaks and / or shoulders, the weight average molecular weight (Mw) is 400 or more and 4000 or less, and the number average molecular weight (Mn) is 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.

[0035] (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 a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used in calculating the molecular weight of the 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 450 or more and 3500 or less, and still more preferably 50 or more.
0 or more and 3000 or less, Mn is 200 or more and 3500 or less,
More preferably, it is desired to be 250 or more and 3000 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 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 the toner production method, a generally used release agent is lower in polarity than the binder resin, so that in the polymerization method in an aqueous medium, a large amount of the release agent is encapsulated inside the 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, and drum fusion and sleeve fusion are easily caused. 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 below in detail.

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 a 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 in refractive index between the binder resin and the wax is 0.18 or less at a temperature of 25 ° C., 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, and also in the production method of the toner by the polymerization method, 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 additivity of atomic groups [Polym.
Eng. Sci. , 14 (2) 147 (1974)].

The SP value of the wax used in the present invention is as follows:
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 a method 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 the 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 degree of crystallinity of the wax is preferably from 10 to 50%, more preferably from 20 to 35%. When the degree of 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.

[0057]

(Equation 1)

As a measuring device, for example, Rotorflex RU300 (Cu target, point focus, output 50 KV / 250 mA) manufactured by Rigaku Denki Co., Ltd. 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 the wax preferably used in the present invention, for example, a synthesis method by an oxidation reaction, a synthesis from a carboxylic acid or 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.

[0060]

(Equation 2)

In order to transfer the above-mentioned 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, and polyvinyltoluene and 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 comonomers 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 cross-linked, 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.

Further, 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, carbon black, a magnetic substance, and a black color tone using a yellow / magenta / cyan colorant shown below are 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 coloring agent 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 method toner, the magnetic material is 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 40 to 150 parts by weight based on 100 parts by weight of the resin component.

The magnetic properties when a 10K Oersted is applied include a coercive force (Hc) of 20 to 300 Oersted, a saturation magnetization (σs) of 50 to 200 emu / g, and a remanent 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 not more than 1/5 of the volume average diameter of the toner particles from the viewpoint of 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 fluorine resin powder (vinylidene fluoride, polytetrafluoroethylene, etc.) and fatty acid metal salt (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 material is contained in a toner as a one-component developer, there is a method of using a magnet built in a developing sleeve to convey 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 triboelectric charging properties 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. Then usually good results are obtained. 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 toner for developing an electrostatic image according to the present invention.

The method for producing the polymerized toner used in the present invention includes a method of atomizing a molten mixture into air using a disk or a multi-fluid nozzle described in Japanese Patent Publication No. 56-13945 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 is difficult from the viewpoint of treatment of waste solvent and flammability of the solvent. The manufacturing equipment is complicated and easily 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 encapsulated in an outer resin layer by a method of measuring a tomographic plane of the toner 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 addition, in the freeze-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.

In the present invention, a specific method for measuring the tomographic plane of the toner is as follows. A toner obtained by sufficiently dispersing a 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 product is stained with ruthenium tetroxide and, if necessary, osmium tetroxide, and then sliced using a microtome equipped with diamond teeth. The morphology of the toner is measured using a transmission electron microscope (TEM). did. 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.

In the case where the 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 colorant, 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.

As the polymerization initiator, 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, a known crosslinking agent or chain transfer agent may be added to control the molecular weight, and the 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 its salts, 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 heteroaggregation 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, as the colorant used in the polymerization method toner, it is necessary to pay attention to the polymerization inhibitory property and the water phase migration property of the colorant. 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 is a schematic view showing an example of a heating roller type fixing device.

The apparatus of this embodiment has a cylindrical heating roller 101 having a heating means such as a heater 101a inside, and rotates clockwise for fixing.

Reference numeral 102 denotes a cylindrical pressing roller as a pressing rotary member, which is pressed against the heating roller 101 and rotates counterclockwise during fixing.

The recording material P, which is transported from the right by the transport belt 103 and has the unfixed toner T adhered as a toner image, is pressed and heated by the heating roller 101 and the pressure roller 102 to be fixed. It is discharged to the left.

Reference numerals 104a and 104b denote separation claws used for separation in order to prevent the recording material P from being wound around the heating roller 101 or the pressure roller 102 and causing a conveyance failure.

Above the upper roller 106, a frictional charging member 107 made of a substance that frictionally charges the highly insulating surface of the upper roller 106 by frictional contact, for example, nylon, rayon, polyurethane foam, or the like, is provided on the upper roller 106. It is provided in pressure contact with the surface.

That is, the upper roller 106 is a metal roller whose surface is coated with PTFE, which is a fluororesin, and has a smooth surface. On the surface of the upper roller 106, a frictional charging member 107 made of a fluorine rubber foam as a foamable elastic body is provided in a pressed state. The upper roller 106 is driven to rotate in the direction of the arrow in FIG.
Is transported in the direction of the arrow. Therefore, the upper roller 106
The highly insulating surface of the upper roller 106 is frictionally charged by the frictional contact with the frictional charging member 107 along with the rotation in the direction of the arrow, and as a result, the recording material P is placed on the highly insulating surface of the upper roller 106 frictionally charged. Dust such as paper dust attached to the upper surface is electrostatically or physically adsorbed. The dust such as paper dust adsorbed on the surface of the upper roller 106 is separated from the surface of the upper roller 106 by the end of the frictional charging member 107 and is collected near the end. Dust such as paper dust collected near this end can be easily cleaned,
It may be stored in a tub (not shown) according to the accumulated amount.

Further, a bias can be applied to the upper roller 106 by a high-voltage power supply (not shown), and it is also possible to positively take in dust such as paper dust which is mainly positively charged. At this time, it is desirable to apply a bias only when the recording material passes through the fixing nip in consideration of scraping by a member such as the frictional charging member 107.

Further, since paper dust is not generated when OHP is passed, there is no need to operate the paper dust removing means 108, and even if a small amount is provided by attaching / detaching means or urging means (not shown),
It is preferable to remove the pressure contact member or release the pressure so as not to damage the pressure contact member.

For example, the heating roller 101 has a thickness of 2 to 5 mm.
mm pipe is used as the core metal, and 200 to 50
One coated with 0 μm thick silicone rubber or Teflon is used.

The pressure roller 102 is, for example, about 10 m
A SUS core metal having a diameter of mφ and a peripheral surface thereof coated with silicone rubber with a thickness of about 3 mm is used.

On the other hand, the heating device of the film heating system is compared with other known heating devices such as a heat roller system, a hot plate system, a belt heating system, a flash heating system and an open heating system or an image heating fixing device. In this case, a linear heating element having a low heat capacity can be used as a heating element, and a film having a low heat capacity of a thin film can be used as a film.
It is possible to shorten the wait time (quick start property), suppress the temperature rise in this machine, and in the image heating fixing device, the fixing point and the separation point can be set separately, so that the offset can be prevented. It has advantages such as solving various drawbacks of other system devices and is effective.

The present invention can be used not only as a fixing device but also as a device and a device for heating a material to be heated, such as a device for heating a recording material carrying an image to improve the surface property, a device for temporarily attaching the material, and the like.

FIG. 2 schematically shows a film heating type apparatus (image heating fixing apparatus).

Reference numeral 6 denotes a heating element (ceramic heater) fixedly supported on the support 3, and the heat-resistant film (fixing film) 1 is brought into close contact with the heating element 6 by a pressure roller 102 as a pressure rotating body. Slide and convey the heat-resistant film 1
A recording medium to be image-fixed as a material to be heated is interposed between the heat-resistant film 1 and the pressure roller 102 in the pressure-contact nip portion (fixing nip portion) N formed by the heating element 6 and the pressure roller 102 with the interposition therebetween. By introducing the material P and nipping and conveying the press-contact nip portion N together with the heat-resistant film 1, the heat of the heating body 6 is applied to the recording material P via the heat-resistant film 1, and Of the unfixed visible image (toner image) T of the recording material P
This is to fix by heating on the surface. The recording material P that has passed through the pressure nip N is separated from the surface of the film 1 and transported.

The heating element 6 is an elongated heat-resistant, insulating and high-heat-conductive substrate 7 whose longitudinal direction is perpendicular to the transport direction a of the heat-resistant film 1 or the recording material P as the material to be heated. A resistance heating element 5 formed along the longitudinal direction of the substrate at a central portion in the lateral direction on the front side of the substrate, power supply electrodes 5a and 5b at both longitudinal ends of the resistance heating element 5, and heating in which the resistance heating element is regulated. It is a linear heating element having a low heat capacity as a whole, including a heat-resistant overcoat layer 8 that protects the body surface, and a temperature detecting element 4 such as a thermistor for detecting the temperature of the heating element provided on the back side of the substrate.

The heating element 6 is fixedly arranged so that the surface on which the resistance heating element 5 is formed is exposed downward and is adhered and held to the rigid and heat insulating heater support 3.

The heating element 6 is composed of the electrodes 5 at both ends of the resistance heating element 5.
When the resistance heating element 5 generates heat over its entire length by power supply to the a and 5b, the temperature rises, and the temperature rise is detected by the temperature detecting element 4, and the detected temperature is a temperature control circuit (not shown).
The power supply to the resistance heating element 5 is controlled so that the heating element is maintained at a predetermined temperature by field back.
That is, the power supply to the resistance heating element 5 is controlled so that the detection output of the temperature detecting element (thermistor) 4 becomes constant during fixing.
It should be noted that a heating device using an alternating magnetic field injection may be used instead of the ceramic heater.

The heat-resistant film 1 is formed in an endless belt shape, and one of the rollers around which the heat-resistant film 1 is stretched is used as a driving roller, and is rotated and conveyed by a frictional force between the driving roller and the inner peripheral surface of the film. Alternatively, there is also a configuration in which the pressure roller 102 is used as a drive roller, or in addition to the pressure roller 102, is rotatably conveyed by a frictional force between a drive roller provided on the outer surface of the film and the outer peripheral surface of the film. There is also a configuration in which a long film is wound and fed out.

The pressure roller 102 as the pressure rotating body is the same as the pressure roller 102 of the apparatus shown in FIG. 1, and includes a metal cored bar 102a and a heat-resistant rubber layer 102b of silicone rubber or the like having good releasability. (Solid wall) elastic roller (hereinafter referred to as a solid roller), which is disposed by pressing the film 1 with a predetermined pressing force by a bearing means and a biasing means (not shown) and pressing the film 1 against the surface of the heating element 6. I have. When the pressure roller 102 is a film drive roller, a rotational force is transmitted to the roller 102 from a drive unit (not shown), and the roller 102 is driven to rotate in a counterclockwise direction indicated by an arrow.

In a preferred embodiment of the present invention, the base layer has an elastic layer and the outermost layer is a fluororesin layer having a specific contact angle with the wax in the toner, and the base layer is provided between the base layer and the surface layer. This is an elastic roller provided with a fluorine rubber layer having a hardness higher than that of the elastic layer having a thickness of 5 to 10 μm. Further, it is more preferable that the outermost layer of the fluorine resin is mainly composed of FEP.

As another preferred embodiment, as shown in FIG. 2, the above-mentioned elastic roller is used as a pressure rotating body, and a heat-resistant film or a belt member is sandwiched between the pressure rotating body and the heating body. The heating target is introduced between the heat-resistant member of the pressure-contact nip portion formed by the body and the pressure-rotating member and the pressure-rotating member, and the pressure-contact nip portion is transported together with the heat-resistant member. This is a heating device that applies the heat of the material to the material to be heated via a heat-resistant member.

As still another preferred embodiment, a heat-resistant film or a 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.

With the above configuration, the elastic roller has excellent releasability over a long period of time and good adhesion between the layers, so that the elastic roller can have excellent durability and low roller hardness.

Further, a heating device (fixing device) of a film heating system or a heating roller system using the elastic roller as a pressure rotating body.
As a result, good heating and fixing properties can be obtained even at low pressure and low temperature, so that the apparatus can be inexpensive.

The layer structure of the pressure roller will be described in detail below.

The elastic layer serving as a base layer plays a role of making a sufficient nip under a low pressure, and is, for example, silicone rubber.

The elastic layer has a material hardness of 30 ° or less (J
IS-A). If the thickness of the elastic layer is increased and the hardness is reduced, the change in the outer diameter due to heat increases, and particularly when the pressure roller is driven, the image is extended. Also, applying high pressure increases the torque of the apparatus, which leads to an increase in the cost of the motor and the like.

The fluororubber layer provided between the base layer and the surface layer serves as an adhesive for coating the fluororesin, and has a higher hardness than the elastic layer of the base layer. The reason for this is that fluorine is in close contact with each other, so that the coating properties are excellent.

The fluororubber layer has a thickness of 5 to 10 μm.
And When the thickness is less than 5 μm, cracks are formed on the surface, and the surface fluororesin does not form a film. If the thickness is more than 10 μm, the roller hardness increases, and a sufficient nip may not be obtained at a low pressure, which is not preferable.

The fluororesin of the outermost layer plays a role of securing the toner releasability for a long period of time.
FA, PTFE and the like.

The thickness of the fluororesin layer is 5 to 30 μm.
m. If the thickness is less than 5 μm, the releasability may be lost when printing 100,000 or more sheets. If the thickness is more than 30 μm, the roller hardness may increase, and a sufficient nip may not be obtained at a low pressure, which is not preferable. .

[0152]

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 formulation was heated to 60 ° C., and was uniformly dissolved and dispersed at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). 10 g of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved therein,
A polymerizable monomer composition was prepared. The polymerizable monomer composition is charged into the aqueous medium, and the mixture is heated at 10,000 rpm under a TK homomixer at 60 ° C. in an N ₂ atmosphere.
After stirring for 0 minutes, the polymerizable monomer composition was granulated. Then, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C.
Allowed to react for hours.

After 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 the 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 fixing device of a commercially available full-color copying machine CLC800 (manufactured by Canon Inc.) uses a roller whose surface layer is coated with 10 μm of FEP as a heating / pressing roller, as shown in FIG. Was removed. Instead, the upper roller 106 has an outer diameter of 20 m.
m PTFE on the surface of a metal roller
Is coated by 50 μm, and the surface is formed to be smooth. On the surface of the upper roller 106, a frictional charging member 107 made of a fluorine rubber foam as a foamable elastic body is provided in a pressed state. 2 of resolution image area 20%, 50%
Using original paper of the kind, plain paper (80 g / m ²
Paper), a paper passing test was performed on each of 10,000 sheets. In addition, an OHP image was formed at the beginning and after the endurance. The paper dust was reliably removed and no offset phenomenon occurred.

Comparative Example 1 In Example 1, a paraffin wax (Mw 470,
Mn 380, viscosity 6.8 mPa · s, SP value 8.3) except that developer No. 2 and the same evaluation was conducted except that the upper roller 106 was not provided.

It is presumed that satisfactory OHP images were not achieved due to offset due to residual paper dust and improper use of wax.

[0159]Example 2 In the first embodiment, the bias is applied to the surface of the upper roller 106 by D.
C-800V, AC2kHz z, 2KVpp only when passing paper
Applied. Two types of originals with 20% and 50% resolution image area
Using a null manuscript, conduct a paper passing test for each 10,000 sheets
Was. Paper dust is reliably removed and offset phenomenon does not occur
Was.

Example 3 A diester wax (Mw 480,
Mn410, viscosity 10.5 mPa · s, SP value 9.1)
Developer No. As a result, good results were obtained.

Example 4 In Example 1, a tetraester wax (Mw 43
0, Mn380 and Mw850 with shoulders,
A developer No. 1 was prepared in the same manner except that a viscosity of 11.6 mPa · s and an SP value of 8.5) were used. As a result, good results were obtained.

Example 5 The fixing device was modified to that shown in FIG. 2 and the surface material was FEP.
A good result was obtained when the same procedure was carried out except for the above.

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 in the same manner except that carbon black was used, and image formation was performed. As a result, excellent color reproducibility of pale colors was obtained, 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. Using this magnetic toner, a commercially available copying machine NP8582
When the surface layer of the fixing unit (manufactured by Canon) was remodeled to FEP, and images were formed, good results were obtained.

[0165]

According to the present invention, by setting the wax contained in the toner to a specific range, a clear full-color O having excellent low-temperature fixability, anti-offset property and excellent transparency is provided.
In addition to providing an image forming method applicable to HP,
Since a large amount of paper dust can be removed without polishing the pressing member, a long life can be achieved.

Needless to say, since paper dust is not generated during OHP sheet passing, it is not necessary to operate the paper dust removing means, and it is important that the pressing member is not damaged even if it is a little.

[Brief description of the drawings]

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

FIG. 2 is a schematic view showing an example of a film heating type apparatus.

[Explanation of symbols]

 Reference Signs List 101 heating roller 2, 102 pressure roller 106 upper roller 107 frictional charging member 108 paper dust removing means T toner P recording material (paper)

Claims (5)

[Claims] 1. An image forming method for fixing an unfixed toner image carried on a recording material to a recording material by a fixing device that heats and / or presses the recording material with a pressure contact member. An image forming method comprising: a paper dust removing unit in contact with the toner; wherein the toner is a toner containing at least a binder resin, a colorant, and a wax. 2. A weight average molecular weight (Mw) of the wax.
Is 400 or more and 4000 or less, and the number average molecular weight (Mn) is 2
2. The structure according to claim 1, wherein the number is not less than 00 and not more than 4000.
2. The image forming method according to 1., 3. The paper dust removing means includes a roller having an insulating surface, and a frictionally charging member provided in pressure contact with the roller and frictionally charging the roller surface by frictionally contacting the roller surface. The image forming method according to claim 1, wherein: 4. The image forming method according to claim 3, wherein the paper dust removing unit applies a bias to the roller surface. 5. An apparatus according to claim 1, wherein said paper dust removing means is not used when OHP is used as a recording material.
The image forming method according to any one of the above.