JPH11258935A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method by which waiting time is substantially eliminated or extremely reduced and a toner image having high quality is obtained without causing an offset and soiling of a pressing member. SOLUTION: As for the image forming method to thermally fix the toner image on a recording material by positioning the recording material 19 between a heating member and the pressing member 18 by using a thermally fixing device having a heating body 11 and the pressing member 18 opposed to and brought into press-contact with the heating body 11, the surface roughness Rz of the pressing member 18 is set to be <=10 μm, and toner has at least toner particles incorporating a binding resin, a colorant and wax and inorganic fine powder, and the wax incorporates hydrocarbon base wax A whose DSC maximum endothermic peak is 130-160 deg.C, acid modified polyolefine wax B whose DSC maximum endothermic peak is 130-160 deg.C and which has the acid number of 1-15 mg KOH/g and the hydrocarbon base wax C whose DSC maximum endothermic peak is 60-120 deg.C.

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 for fixing a visible image formed by toner on a recording material in electrophotography, electrostatic printing, and magnetic recording.

[0002]

2. Description of the Related Art An electrophotographic method is disclosed in U.S. Pat.
A large number of devices are known as described in Japanese Patent Publication No. 7,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748, but generally a photoconductive substance is used. An electric latent image is formed on the photoreceptor by various means, and then the latent image is developed using toner. If necessary, a toner image is transferred to a transfer material (recording material) such as paper, and then heated. The toner is fixed by heat, pressure, heat or pressure, or a solvent vapor to obtain a copy, and the remaining toner not transferred onto the photoreceptor is cleaned by various devices.
The above steps are repeated.

In recent years, such copying apparatuses have been used not only as office work copying machines for simply copying original documents, but also for copying high-definition images such as printers or graphic designs as computer outputs. We have begun.

As for printer devices, LED and LBP printers have become the mainstream in the recent market, and higher resolution, that is, those which have been conventionally 240,300 dpi, have become 600,
800 and 1200 dpi. Accordingly, higher definition has been required for the developing system. In addition, the functions of the copying machine have been advanced, and the digital copying machine is moving toward digitalization. This direction is
Since the method of forming an electrostatic charge image with a laser is mainly used, the method is also proceeding in the direction of high resolution, and here, similarly to a printer, a high-resolution and high-definition developing method has been required. -112253 and JP-A-2-284
No. 158 proposes a toner having a small particle size. As a result, higher reliability has been strictly pursued, and the required performance has become more sophisticated.
Unless the performance of the image forming apparatus including the toner can be improved, a better machine cannot be realized. Further, as an apparatus for fixing a visible toner image to a recording material, an unfixed toner visible image is fixed by a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and pressing against the heating roller. A heat roller fixing system in which a recording material holding a sheet is heated while being nipped and conveyed is often used.
Alternatively, a belt fixing system described in U.S. Pat. No. 3,578,797 is known.

However, in the above-described conventional heat roller fixing, (1) there is a so-called wait time during which the image forming operation is prohibited until the heat roller reaches a predetermined temperature. (2) Optimal temperature of the heating roller to prevent fixing failure due to fluctuation of the temperature of the heating roller due to passage of the recording material or other external factors, transfer of the developer to the heating roller, so-called offset phenomenon. In order to achieve this, the heat capacity of the heating roller or the heating element must be increased, which requires a large amount of electric power. (3) When the recording material is discharged through the heating roller because the temperature of the roller is low, the recording material and the developer on the recording material are slowly cooled, so that the adhesiveness of the developer is high. Also, in combination with the curvature of the roller, a paper jam may occur due to offset or entanglement of the recording material. (4) The configuration is such that the high-temperature heating roller is directly in contact with the hand, and there is a problem in safety or a protective member is required.

Also, in the belt fixing system described in US Pat. No. 3,578,797, the above-mentioned problems (1) and (2) of the heat roller fixing have not been fundamentally solved.

JP-A-63-313182 by the present applicant
In Japanese Patent Application Publication No. 2 (1995) -207, an image forming method in which a toner-visible image is heated via a heat-resistant sheet moved by a low-heat-capacity heating element heated in a pulsed manner and fixed on a recording material has a short wait time and low power consumption. Has been proposed.

In the heating method using a heating roller or a film, the toner image surface of a sheet to be fixed is passed through the surface of a heat roller or a film formed of a material having a releasable property with respect to toner while the surface is in contact therewith. The fixing is performed by the following. In this method, since the surface of the heat roller or the film comes into contact with the toner image of the sheet to be fixed, the thermal efficiency at the time of fusing the toner image onto the sheet to be fixed is extremely good, and the fixing can be performed quickly. It is very effective in an electrophotographic copying machine. However, in the above method, since the toner image is in contact with the surface of the heat roller or the film in a molten state, a part of the toner image adheres and transfers to the fixing roller or the surface of the film, and is transferred again to the next sheet to be fixed. This may cause a so-called offset phenomenon, and may stain the sheet to be fixed. Preventing toner from adhering to the heat fixing roller or the film surface is one of the essential conditions of the heat fixing method.

In recent years, the use of recycled paper has been increasing year by year from the viewpoints of environmental problems and resource protection. Among these recycled papers, a large amount of additives such as calcium carbonate is used for the purpose of improving the whiteness of the paper. There is a thing contained in. When these sheets are used, there has been a problem that the additive and the toner separated from the sheets accumulate on the pressing member of the image forming method and appear as image stains.

Conventionally, in order to prevent the toner from adhering to the surface of the fixing roller, a wax such as low molecular weight polyethylene or polypropylene which can be sufficiently melted when heated in order to increase the releasability of the toner has been used. ,
Although effective for preventing offset, it was still insufficient for preventing contamination of the pressure member. Further, when a large amount of wax such as low molecular weight polyethylene or polypropylene is added to prevent contamination, the charging characteristics of the toner become unstable, which tends to cause problems such as a decrease in image density and an increase in fog. Was urgently needed.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to obtain a high-quality and high-definition image even for a variety of transfer materials, and to substantially reduce the wait time. It is an object of the present invention to provide an image forming method in which a high quality toner image is obtained without causing an offset phenomenon or a pressing member stain even when used for a long time with low power consumption or low power consumption. .

[0012]

The present invention provides i)
Forming an electrostatic latent image on the electrostatic latent image holding member, and (ii) developing the electrostatic latent image with a toner carried on a toner carrier to form a toner image; and (iii) forming the toner image. Is transferred onto a recording material, and (iv) a heating and fixing device having a heating member and a pressing member that is in pressure contact with the heating member, and the recording material is positioned between the heating member and the pressing member. And an image forming method for heating and fixing the toner image on a recording material, wherein the pressing member has a surface roughness Rz of 10 μm or less, and the toner contains at least a binder resin, a colorant, and a wax. The wax has a DSC maximum endothermic peak of 130 to 160 ° C. and a DSC maximum endothermic peak of 130 to 1
An image forming method comprising: an acid-modified polyolefin wax B having an acid value of 1 to 15 mgKOH / g at 60 ° C .; and a hydrocarbon wax C having a DSC maximum endothermic peak of 60 to 120 ° C. .

According to the present invention, the above-mentioned object is achieved by using a wax having a different melting property and an acid-modified wax (particularly, at a specific ratio) so that the wax can be uniformly dispersed in the toner particles. In addition, the releasability of the toner from the pressing member can be particularly exhibited in a wide temperature range, and the surface roughness of the pressing member can be set to a certain value or less, so that the heating member having no direct heating element can be used. It is considered that excellent releasability is maintained in the temperature change region of the pressure member (the surface temperature randomly changes from a state close to room temperature to a vicinity of the fixing temperature depending on the environment and use conditions).

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Surface roughness Rz of a pressing member of the present invention
Regarding the above, by setting the Rz to 10 μm or less, embedding of additives such as calcium carbonate and talc and minute paper fibers contained in the printing paper into the pressure member can be prevented well.
Preferably, Rz is 0.1 to 10 μm, more preferably 0.1 to 7 μm, and still more preferably 0.1 to 5 μm.

If Rz exceeds 10 μm, additives such as calcium carbonate and talc and fine paper fibers contained in the printing paper are liable to accumulate, which is not preferable. The measurement of the surface roughness Rz of the pressing member of the present invention is based on JIS B060.
1 based on the surface roughness
Measurements were made at H3500 at a total of 6 points, 3 points in the axial direction and 2 points in the circumferential direction, and the average value was determined.

The wax of the present invention is used when the amount X of the wax in the toner is in the range of 1 to 10% by weight. Preferably 1.5 to 8% by weight, 2 to 6% by weight
Is particularly preferred.

When X is less than 1% by weight, the effect of preventing the pressure member from being stained is insufficient. When X exceeds 10% by weight, the wax dispersion in the toner particles is deteriorated, and the developing property is apt to be lowered.

The ratio of waxes A, B and C used in the present invention in the toner particles is defined as Xc ≦ Xa and Xc ≦ Xb.
It is preferred that

When Xc exceeds Xa or Xb, the dispersibility of the wax similarly deteriorates, and the desired releasability and developability tend to decrease.

The wax A satisfactorily prevents the pressing member from being stained mainly when the surface temperature of the pressing member is in a temperature range of about 130 to 250 ° C. Further, the wax C satisfactorily prevents the pressing member from being contaminated when the surface temperature of the pressing member is 130 ° C. or lower. Further, the wax B has the same effect of preventing the press member from being stained as the wax A, and improves the dispersibility of each wax when three different waxes are used. The temperature range of the DSC endothermic peak of waxes A and B is preferably in the range of 130 to 160 ° C, more preferably 130 to 150 ° C. When the DSC maximum endothermic peak temperature of waxes A and B exceeds 160 ° C., the fixability tends to deteriorate. Wax A and B
If the DSC maximum endothermic peak temperature is less than 130 ° C., the developability tends to deteriorate. The acid value of wax B is 1 to 15
The range of mgKOH / g is good. If it is less than 1 mgKOH / g, the effect of improving the wax dispersibility is small, and
If it exceeds g, the developability tends to deteriorate. The temperature range of the maximum DSC endothermic peak of wax C is 60-12.
The temperature range is preferably 0 ° C, more preferably 90 to 120 ° C. If the temperature is lower than 60 ° C., the storability and developability tend to be deteriorated.

In order to faithfully develop finer latent image dots for higher image quality, the toner has a weight average diameter of 4 μm.
It is preferably about 8 μm. In the case of a toner having a weight average diameter of less than 4 μm, image unevenness due to fog and poor transfer is likely to occur. When the weight average diameter of the toner exceeds 8 μm, reproducibility of one dot and image quality of a line image tend to deteriorate.

The average particle size and particle size distribution of the toner can be measured by various methods such as Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter). Is connected to an interface (manufactured by Nikkaki) that outputs the number distribution and volume distribution and a PC9801 personal computer (manufactured by NEC).
A 1% NaCl aqueous solution is prepared using graded sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte in which the sample is suspended is subjected to dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the volume and number of toner particles having a size of 2 μm or more are measured using the Coulter Multisizer with an aperture of 100 μm. (D ₄ ) was determined.

Hydrocarbon wax A used in the present invention
Examples thereof include a homopolymer of propylene and a copolymer of propylene and another olefin, and a copolymer of propylene and ethylene is particularly preferable.

The acid value used in the present invention is 1 to 15 m.
Examples of the acid-modified polyolefin wax B having gKOH / g include acid-modified polyethylene and acid-modified ethylene-propylene copolymer. In particular, the above-mentioned polyolefin wax whose molecular terminal has been modified by an acid monomer selected from at least one of maleic acid, maleic acid half ester and maleic anhydride is preferable.

The hydrocarbon wax C used in the present invention includes paraffin wax and derivatives thereof,
Examples include microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, linear polyolefin wax and its derivatives, carnauba wax and its derivatives, and the like. Derivatives also include block copolymers with oxides and vinyl monomers, modified grafts, modified alcohols, and the like.

Among them, low-molecular-weight polyethylene, Fischer-Tropsch wax and aliphatic alcohol have a ratio Mw / Mn of weight-average molecular weight Mw to number-average molecular weight Mn of 1.
Those in the range of 0 to 2.0 are particularly preferred.

In the present invention, the molecular weight distribution of the wax is measured by GPC (gel permeation chromatography) under the following conditions.

<GPC Measurement Conditions for Wax> Apparatus: GPC-150C (manufactured by Waters) Column: Duplex of GMH-HT (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (added with 0.1% ionol) ) Flow rate: 1.0 ml / min. Sample: 0.4 ml of 0.15% by weight 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. Further, the molecular weight of the wax is calculated by conversion using a conversion formula derived from the Mark-Houwink viscosity formula.

In the present invention, the DSC measurement of the wax is
From the measurement principle, it is preferable to measure with a highly accurate differential scanning calorimeter of the internal heating type input compensation type. For example, DSC-7 manufactured by PerkinElmer can be used. The measurement method is AST
Performed according to MD3418-82. The DSC curve used in the present invention was obtained by raising the temperature once and taking a pre-history, and then calculating the temperature 3
A DSC curve measured when the temperature is lowered and raised at a rate of 10 ° C./min in the range of 0 to 180 ° C. is used.

The binder resin of the toner according to the present invention includes:
Styrene such as polystyrene and polyvinyltoluene and its substituted homopolymer; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene- Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate Copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer , Styrene-pig Styrene copolymers such as ene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, Polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin, rosin, modified rosin, tempel resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, paraffin Wax, carnauba wax and the like can be used alone or in combination. Among them, styrene-based copolymers, particularly styrene-acrylic-based copolymers, polyester resins, and mixtures thereof are preferable in terms of developing characteristics and fixing characteristics.

In the toner of the present invention, it is preferable that a charge control agent is blended (internally added) to the toner particles or mixed (externally added) with the toner particles. The charge control agent enables optimal charge control according to the development system.
In particular, in the present invention, it is possible to further stabilize the balance between the particle size distribution and the charge amount. The following substances control the toner to be negatively charged.

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

The following substances are controlled to be positively charged.

Modified products such as nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate, and phosphonium salts which are analogs thereof Onium salts such as, for example, these lake pigments, triphenylmethane dyes and these lake pigments (as the lacking agent, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanic acid) , Ferrocyanide, etc.), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyl Diorgano tin borate such as Suzuboreto; can be used in combination singly or two or more kinds.

The above charge control agents are preferably used in the form of fine particles. In this case, the number average particle size of these charge control agents is particularly preferably 4 μm or less, more preferably 3 μm or less. When these charge control agents are internally added to the toner, it is preferable to use 0.1 to 20 parts by weight, particularly 0.2 to 10 parts by weight, based on 100 parts by weight of the binder resin.

As the coloring agent used in the present invention, carbon black, a magnetic substance, and a black / toned colorant using the following yellow / magenta / cyan coloring agents 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, 97, 109, 1
10, 111, 120, 127, 128, 129, 14
7, 168, 174, 176, 180, 181, 191
Etc. 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, 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, 62, 66, etc. 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 colorant is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the resin.

When a magnetic material is used as a black colorant, unlike other colorants, 30 parts per 100 parts by weight of resin is used.
Used in an amount of up to 200 parts by weight.

Examples of the magnetic material include metal oxides containing elements such as iron, cobalt, nickel, copper, magnesium, manganese, aluminum and silicon. Among them, those containing iron oxide as a main component, such as ferric oxide and γ-iron oxide, are preferable. Further, other metal elements such as a silicon element or an aluminum element may be contained from the viewpoint of controlling the chargeability of the toner. These magnetic particles are made of B by the nitrogen adsorption method.
ET specific surface area is preferably 2-3 m ² / g, especially 3-28
Magnetic powder having m ² / g and Mohs hardness of 5 to 7 is preferred.

As the shape of the magnetic material, octahedron, hexahedron,
There are spheres, needles, scales, etc., but octahedrons, hexahedrons, spheres, irregular shapes and the like with little anisotropy are preferred in order to increase the image density. The average particle size of the magnetic material is 0.05 to
1.0 μm is preferred, and more preferably 0.1 to 0.1 μm.
6 μm, and more preferably 0.1 to 0.4 μm.

The amount of the magnetic material is 3 with respect to 100 parts by weight of the binder resin.
0 to 200 parts by weight, preferably 40 to 200 parts by weight, more preferably 50 to 150 parts by weight. If the amount is less than 30 parts by weight, in a developing device that uses a magnetic force to transport the toner, the transportability is insufficient, and the developer layer on the developer carrier tends to be uneven, resulting in image unevenness. , The image density tends to decrease. On the other hand, if it exceeds 200 parts by weight, a problem tends to occur in the fixing property.

In some cases, the magnetic iron oxide used in the toner of the present invention may be treated with a silane coupling agent, a titanium coupling agent, titanate, aminosilane, an organosilicon compound, or the like.

Examples of the silane coupling agent used for the surface treatment of the magnetic iron oxide include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, trimethylchlorosilane, and allyldimethylchlorosilane. , Allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilylmercaptan, triorganosilyl acrylate , Vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxy San, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane and the like.

Examples of the titanium coupling agent include isopropoxytitanium triisostearate, isopropoxytitanium dimethacrylate / isostearate,
Isopropoxy titanium tridodecyl benzene sulfonate, isopropoxy titanium tris dioctyl phosphate, isopropoxy titanium tri N-ethylaminoethyl aminato, titanium bis dioctyl pyrophosphate oxy acetate, bis dioctyl phosphate ethylene dioctyl phosphite, di-n-butoxy -Bis triethanol aminato titanium etc. are mentioned.

Examples of the organosilicon compound include silicone oil. Preferred silicone oils are those having a viscosity of about 30 to 10,000 centistokes at 25 ° C., such as dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil. Are preferred.

As the inorganic fine powder contained in the toner of the present invention, known ones may be used, but silica, alumina, and silica are used for improving the charge stability, developability, fluidity, and storage stability.
It is preferable to be selected from titania or a composite oxide thereof. Furthermore, silica is more preferable. For example, as the silica, both a so-called dry method produced by vapor phase oxidation of a silicon halide and an alkoxide, and a so-called wet silica produced from an alkoxide, a water glass and the like, and a dry silica called a fumed silica can be used. However, there are few silanol groups on the surface and inside the silica fine powder, and Na ₂ O, SO ₃
Dry silica having a small production residue such as ^2- is more preferable.
In the case of fumed silica, for example, in the manufacturing process,
By using other metal halides such as aluminum chloride and titanium chloride together with the silicon halides, it is possible to obtain composite fine powders of silica and other metal oxides, and these are also included.

The inorganic fine powder used in the present invention is the specific surface area by nitrogen adsorption measured by BET method is 30 m ² / g or more, give good results, especially in the range of 50 to 400 m ² / g, the toner 100 weight It is particularly preferable to use 0.1 to 8 parts by weight, preferably 0.5 to 5 parts by weight, more preferably more than 1.0 to 3.0 parts by weight of silica fine powder with respect to parts by weight.

The inorganic fine powder used in the present invention comprises:
The primary particle size is preferably 30 nm or less.

The inorganic fine powder used in the present invention comprises:
Silicon varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, other organosilicon compounds, organic It is possible and preferable to use a treating agent such as a titanium compound or a combination of various treating agents.

For example, as the silane coupling agent,
For example, typically, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyl Examples include triacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane and the like. The silane coupling agent treatment of the inorganic fine powder is performed by a dry process in which a vaporized silane coupling agent is reacted with a cloud of the inorganic fine powder by stirring or the like, or a silane cup in which the inorganic fine powder is dispersed in a solvent. The treatment can be performed by a generally known apparatus such as a wet method in which a ring agent is dropped and reacted.

It is particularly preferable that the inorganic fine powder used in the present invention is further treated with at least silicone oil.

The average particle size of the inorganic fine powder treated with silicone oil is preferably 0.1 μm or less, more preferably 0.002 to 0.05 μm. The oil treatment amount of the silicone oil-treated inorganic fine powder is preferably from 1 to 30% by weight, particularly preferably from 1 to 20% by weight, based on the treated inorganic fine powder. The preferred range of the amount of the silicone oil-treated inorganic fine powder added to the toner is from 0.3 to
It is 3.0% by weight, particularly preferably 0.5 to 2% by weight. Further, the oil viscosity of the silicone oil is preferably 1 to 10000 cSt, and 50 to 1000 cSt.
Is more preferable.

The silicone oil used in the present invention is:
Examples thereof include dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil. A known technique is used for the apparatus for treating the silicone oil. For example, the silica fine powder and the silicone oil may be directly mixed by using a mixer such as a Henschel mixer, or a device for spraying the silicone oil onto the base silica may be used. good. Alternatively, it may be prepared by dissolving or dispersing silicone oil in an appropriate solvent, mixing with a base silica fine powder, and removing the solvent.

In the toner of the present invention, other additives such as lubricant powders such as Teflon powder, zinc stearate powder and polyvinylidene fluoride powder; cerium oxide powder, silicon carbide Powder,
Abrasives such as strontium titanate powder; fluidity imparting agents such as titanium oxide powder and aluminum oxide powder; anti-caking agents; or conductivity imparting agents such as carbon black powder, zinc oxide powder and tin oxide powder, Organic and inorganic fine particles of opposite polarity can also be used in small amounts as a developer improver.

In preparing the toner according to the present invention, a binder resin, a pigment, a dye or a magnetic material as a colorant, a charge controlling agent, and other additives are sufficiently mixed by a mixer such as a ball mill. Using a hot kneader such as a heating roll, kneader or extruder, melt or knead and knead the resin to make the resins compatible with each other, disperse or dissolve the pigments or dyes. After classification, the toner according to the present invention can be obtained.

Further, as another apparatus for obtaining the toner according to the present invention, the toner can be manufactured by a polymerization method. This suspension polymerization method toner contains a polymerizable monomer and the charge control agent of the present invention, a pigment or dye, a magnetic iron oxide, a polymerization initiator (and, if necessary, a crosslinking agent and other additives).
Is uniformly dissolved or dispersed into a monomer composition, and then the monomer composition or a prepolymerized version of the monomer composition is added to a continuous layer containing a dispersion stabilizer (eg, water). The toner particles having a desired particle size are dispersed by using an appropriate stirrer and simultaneously subjected to a polymerization reaction.

Next, the heat fixing structure of the present invention applicable to the image forming method of the present invention will be specifically described.

In the present invention, a heating roll, which will be described later, can be used as the heating element, but has a smaller heat capacity than the heating roll and has a linear heating section. Preferably it is 300 ° C.

The film located between the heating element and the pressing member is preferably a heat-resistant sheet having a thickness of 1 to 100 μm, and these heat-resistant sheets include polyester, PET and the like. (Polyethylene terephthalate), PEA (tetrafluoroethylene-perfluoroalkylvinyl ether copolymer), PTFE (polytetrafluoroethylene), polyimide, polyamide, etc., as well as metal sheets such as aluminum and metal sheets and polymer sheets The configured laminated sheet is used. As a more preferable structure of the film, these heat-resistant sheets have a release layer and / or a low-resistance layer.

FIG. 1 shows a structural diagram of an example of a fixing device for carrying out the method of the present invention.

Reference numeral 11 denotes a low-heat-capacity linear heating element fixedly supported by the apparatus, and has a thickness of 1.0 mm and a width of 10 m as an example.
m, an alumina substrate 12 having a longitudinal length of 240 mm
3 is applied to a width of 1.0 mm, and is energized from both ends in the longitudinal direction. The energization is performed by applying a pulse corresponding to a desired temperature and energy release amount controlled by the temperature detecting element 14 by changing the pulse width in a pulse-like waveform of DC 100 V and a cycle of 20 msec. Approximate pulse width is 0.5 ms
c to 5 msec.

The fixing film 15 moves in the direction of the arrow in FIG. As an example of this fixing film, a thickness of 20 μm
Heat-resistant film, for example, polyimide, polyetherimide, PES, PFA
This is an endless film in which a release layer obtained by adding a conductive agent to a fluororesin such as FE or PAF is coated by 10 μm. Generally, the total thickness is 100 μm, more preferably less than 40 μm. The film is driven by the driving roller 16 and the driven roller 1
7 moves without wrinkles in the direction of the arrow due to the drive tension by 7.

Reference numeral 18 denotes a pressing member, which is provided with a rubber elastic layer such as silicone rubber on a metal or heat-resistant resin core, and further has a surface roughness R via a primer layer having a thickness of 1 to 3 μm.
z has a release layer of a fluororesin of 10 μm or less. The pressing member presses the heating body through the film with a total pressure of 4 to 20 kg and rotates by pressing against the film. The unfixed developer 20 on the transfer material 19 is guided to a fixing section by an entrance guide 21 and obtains a fixed image by the above-described heating.

The endless belt has been described above. However, as shown in FIG. 2, a sheet feed shaft 24 and a take-up shaft 27 may be used, and the fixing film may be an endless film.

FIG. 3 is a structural view of another fixing device for carrying out the method of the present invention. Reference numeral 50 denotes a heating roller base material, which internally includes a heating body 52 fixed and supported. A release layer 51 of a fluororesin is formed on the heating roller base via a primer layer or the like.

Reference numerals 53, 54, and 55 denote pressing members, which are provided with a rubber elastic layer 54 of silicone rubber or the like on a metal or heat-resistant resin core 53, and further with a surface roughness of 1 to 3 μm through a primer layer. It has a release layer 55 of fluororesin having a thickness Rz of 10 μm or less. The pressing member presses the heating roller with a total pressure of 4 to 50 kg and rotates by pressing. The unfixed developer 20 on the transfer material 19 obtains a fixed image by the above-described heating.

The image forming apparatus is applicable to all fixing devices such as a copying machine, a printer, a facsimile and the like which use a developer.

In the low heat capacity linear heating element 11, when the temperature detected by the temperature detecting element 14 is T ₁ , the surface temperature T ₂ of the film 15 facing the resistance material 13 is substantially equal to T ₁ . Further, the film surface temperature T ₃ at a portion where the film 15 is peeled from the developer fixing surface is substantially equal to the temperature and the temperatures T ₁ and T _2.

[0073]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.
“Parts” means “parts by weight”.

(Toner Production Example 1) 100 parts of magnetic material (spherical magnetite) 100 parts of styrene-n-butyl acrylate-n-butyl maleate half-ester copolymer (copolymerization ratio 7: 3, Mw = 350,000) Parts-Iron complex of monoazo dye (negative charge control agent) 2 parts-Ethylene-propylene copolymer (DSC endothermic peak temperature 146 ° C) 4 parts-Maleic anhydride-modified ethylene propylene copolymer (acid value 3.5, 1 part of low molecular weight polyethylene (Mw / Mn = 1.35, DSC endothermic peak temperature of 105 ° C) 3 parts

The above materials were mixed in a blender,
Melted and kneaded with a twin-screw extruder heated to ℃, the cooled kneaded material is roughly pulverized by a hammer mill, the coarsely pulverized material is finely pulverized by a jet mill, and the obtained finely pulverized material is classified by an air classifier. Thus, a black fine powder was obtained. Obtained black fine powder 10
To 0 part, 1.2 parts of hydrophobic silica fine powder (silicone oil and hexamethyldisilazane-treated BET specific surface area: 120 m ² / g) were added, stirred and mixed by a Henschel mixer, and then sieved with a 150 mesh sieve. The coarse particles were removed to obtain Magnetic Toner 1. The weight average particle diameter of the obtained magnetic toner 1 was 6.8 μm. Table 1 shows the physical properties of Magnetic Toner 1.

(Toner Production Example 2) 80 parts of magnetic material (spherical magnetite) 100 parts of styrene-n-butyl acrylate-n-butyl maleate half ester copolymer (copolymerization ratio 8: 2, Mw = 260,000) 100 Part-Iron complex of monoazo dye (negative charge control agent) 2 parts-Ethylene-propylene copolymer (DSC endothermic peak temperature 146 ° C) 4 parts-Maleic anhydride-modified ethylene propylene copolymer (acid value 7, DSC endotherm) 1 part of Fischer-Tropsch wax (Mw / Mn = 1.7, DSC endothermic peak temperature of 110 ° C.)

Using the above components, a fine black powder was obtained in the same manner as in Production Example 1. For 100 parts of the obtained black fine powder,
1.0 part of hydrophobic silica fine powder (silicone oil and hexamethyldisilazane treated BET specific surface area 120 m ² /
g) was added to obtain Magnetic Toner 2. Table 1 shows the physical properties of the obtained magnetic toner 2.

(Toner Production Examples 3 to 7) Production Example 1 except that the amount of the magnetic material, the wax, and the particle size of the toner were changed respectively.
In the same manner as in the above, magnetic toner 3 was obtained. Table 1 shows the physical properties of the obtained magnetic toners 3 to 7.

(Toner Comparative Production Examples 1 to 3) Magnetic toners 8, 9, and 10 were obtained in the same manner as in Production Example 1 except that the amount of wax, the particle size, and the particle size distribution were changed. Table 1 shows the physical properties of the obtained magnetic toners 8, 9, and 10.

[0080]

[Table 1]

<Example 1> An image forming method of a commercially available laser beam printer LBP-430 (manufactured by Canon) was modified to the following configuration, and performed under the following conditions.

In the fixing device shown in FIG.
The surface temperature of the temperature measuring element 14 was 150 ° C., the total pressure between the heating body 11 and the pressure roller 18 was 6 kg, the nip between the pressure roller and the film was 3 mm, and the rotation speed of the pressure roller 18 was 38 mm / sec. . As the pressure roller, a roller coated with a tetrafluoroethylene-hexafluoropropylene copolymer and having a surface roughness Rz of 0.8 μm was used.

As the heat-resistant sheet, a polyimide film having a thickness of 50 μm and having a low-resistance release layer in which a conductive material was dispersed in PTFE on a contact surface with the transfer material was used.

Using the magnetic toner 1 of Toner Production Example 1 under the above setting conditions, a print test was performed at 23 ° C. and a relative humidity of 60% at a print speed of 2 sheets / 10 minutes (A4 vertical feed). The degree of dirt on the pressure roller and the dirt on the image were evaluated. The printing paper used was a paper having a calcium carbonate content of about 48% and a weighing of 90 g / m ² .

Further, continuous printing was performed on 4000 sheets in an environment of 23 ° C. and a relative humidity of 60%, and the image density was evaluated at the beginning (100th sheet) and at the end of printing (4000th sheet). Table 2 shows the evaluation results.

<Examples 2 to 10> Evaluations were performed in the same manner as in Example 1 except that the toner and the pressure roller were changed. Table 2 shows the evaluation results.

<Embodiment 11> A fixing device of a commercially available laser beam printer LBP-830 (manufactured by Canon) is shown in FIG.
The fixing device was modified in the same manner as in Example 1 except that a roller having a surface roughness Rz = 2.5 μm coated with a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer as a surface layer was used as a pressing member. When the evaluation was performed, similarly good results were obtained. Table 2 shows the evaluation results.

Comparative Examples 1 to 3 Evaluations were performed in the same manner as in Example 1 except that the toner and the pressure roller were changed. Table 2 shows the evaluation results.

[0089]

[Table 2]

Evaluation of Printout Image (1) Pressure Roller Staining The pressure roller stainability was evaluated by printing out a sample image having an image area ratio of about 5% and measuring the degree of the pressure roller stain after 4000 sheets. ：: There is no stain on both the image and the pressure roller. ：: Slight stain is generated on the pressure roller, but there is no problem on the image. X: Significant stain is generated on the pressure roller, and stain is also generated on the image. 2) Image Density The image density was measured using a “Macbeth reflection densitometer” (manufactured by Macbeth) at five locations of a solid black portion of 5 mm in length and width on a printed image, and the average value was calculated. ： １: 1.30 or more, extremely good Δ: less than 1.30, 1.00 or more, good without practical problems ×: less than 1.00, insufficient image density

[0091]

According to the present invention, in an image forming method having substantially no or very short wait time and low power consumption, resistance to pressure roller contamination and offset resistance are achieved. Further, it is possible to obtain a high-quality image.

[Brief description of the drawings]

FIG. 1 is a structural diagram of an example of a fixing device for implementing a method of the present invention.

FIG. 2 is a structural diagram of another example of a fixing device for implementing the method of the present invention.

FIG. 3 is a structural diagram of another fixing device for carrying out the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Low-heat-capacity linear heating element 12 Alumina substrate 13 Resistance material 14 Temperature measuring element 15 Fixing film 16 Driving roller 17 Follower roller 18 Rubber elastic layer (Pressing member) 19 Transfer material (Recording material) 20 Unfixed developer (Developer 21 entrance guide 24 sheet feed shaft 27 take-up shaft 50, 53 core metal 51, 55 release layer 52 heater (heating body) 54 elastic layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 9/08 365

Claims (8)

[Claims] (I) forming an electrostatic latent image on an electrostatic latent image holding member, and (ii) developing the electrostatic latent image with toner carried on a toner carrier to form a toner image And (ii
i) transferring the toner image onto a recording material, and (iv) using a heating and fixing device having a heating member and a pressing member which is in pressure contact with the heating member, and applying the recording material to the heating member and the pressing member. And an image forming method for heating and fixing the toner image on a recording material, wherein the surface roughness Rz of the pressure member is 10 μm or less, and the toner includes at least a binder resin, a colorant, It has toner particles containing a wax and inorganic fine powder, and the wax has a DSC maximum endothermic peak of 130 to 160.
C., a hydrocarbon wax A having a DSC maximum endothermic peak of 130 to 160 ° C., an acid-modified polyolefin wax B having an acid value of 1 to 15 mg KOH / g, and a DSC maximum endothermic peak having a hydrocarbon endothermic peak of 60 to 120 ° C. C. and an image forming method. 2. The heating and fixing device has a fixedly supported heating element, and a pressure member which is in opposition and pressure contact with the heating element and is in close contact with the heating element via a film, and the toner image is The image forming method according to claim 1, wherein the recording material is positioned between the film and the pressing member so as to be in contact with the film, and the toner image is heated and fixed to the recording material. 3. The acid-modified polyolefin wax B,
3. The image forming method according to claim 1, wherein the polyolefin wax is a polyolefin wax whose molecular terminal is modified by at least one acid monomer selected from maleic acid, maleic acid half ester or maleic anhydride. 4. The hydrocarbon wax C has a weight average molecular weight Mw in a molecular weight distribution measured by GPC.
And the number average molecular weight Mn (Mw / Mn) is 1.0 to
The image forming method according to claim 1, wherein the range is 2.0. 5. The toner according to claim 1, wherein the total wax content X is 1
And a weight ratio Xa of the hydrocarbon wax A, a weight ratio Xb of the acid-modified polyolefin wax B, and a weight ratio Xc of the hydrocarbon wax C.
5. The image forming method according to claim 1, wherein the following relationship is satisfied: Xc ≦ Xa, Xc ≦ Xb. 6. The image forming method according to claim 1, wherein the inorganic fine powder has a silica fine powder at least treated with silicone oil. 7. The toner has a weight average particle size D _{4 of 4} to 8 μm.
The image forming method according to claim 1, wherein m is m. 8. The image forming method according to claim 1, wherein the toner is a magnetic toner containing a magnetic material.