JP2002040708A - Image forming toner and image forming method - Google Patents

Abstract

(57) [Problem] To provide an image forming toner which maintains good fixability and does not cause contamination of a pressure roller. SOLUTION: A heating and fixing device for holding and heating a member to be heated P on which a toner visible image T is formed and applying heat energy and pressure to the member to be heated is provided. Thermal conductivity 0.20 W / mk on gold
An image forming toner used in an image forming method in which a pressure is applied to the heated member by a pressing member 6 having a heat-resistant elastic layer, and the toner visible image is heated and fixed to the heated member. The toner contains a binder resin, a colorant and a wax, and contains a hydrophobic metal oxide fine powder as an external additive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming toner for fixing a visible image formed by a toner to a recording material in electrophotography, electrostatic printing, and magnetic recording, and an image forming method.

[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 a 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 a high-resolution and high-definition developing method is required similarly to a printer. -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 image of toner on a recording material, an unfixed image is formed by a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and pressing against the heating roller. 2. Description of the Related Art A heat roller fixing method in which a recording material holding a toner visible image 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 method, there are (1) a time period during which the image forming operation is prohibited until the heat roller reaches a predetermined temperature, that is, a so-called wait time; It is necessary to maintain the heating roller at an optimum temperature in order to prevent fixing defects due to fluctuations in the temperature of the heating roller due to other external factors and transfer of the developer to the heating roller, so-called offset phenomenon. Therefore, the heat capacity of the heating roller or the heating element must be increased, which requires a large amount of electric power. (3) Since the temperature of the roller is low, when the recording material is discharged through the heating roller, Since the recording material and the developer on the recording material are slowly cooled, the adhesiveness of the developer becomes high,
In combination with the curvature of the roller, a paper jam may occur due to offset or entanglement of the recording material; (4) a configuration in which the high-temperature heating roller directly touches the hand,
There is a problem with safety or a need for a protective member;

Also, in the belt fixing method 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.

[0008] 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 the 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 on 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 surface of the heat roller or the film contacts the toner image in a molten state,
A part of the toner image adheres and transfers to the fixing roller or the film surface, and re-transfers to the next sheet to be fixed, causing a so-called offset phenomenon, which may stain the sheet to be fixed. Preventing the 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 viewpoint 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 are those contained in. When these papers are used, there has been a problem that the additive and toner separated from the paper accumulate on the pressurizing member of the image forming method and appear as image stains, thereby achieving miniaturization of the printer device. As a result, the problem of image contamination has become more and more serious, along with the reduction in size and power consumption of the fixing device and the speeding up of the printer device, and it has been urgently necessary to overcome these problems.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to achieve a shorter heating start-up time and a lower power consumption than a conventional on-demand type heat fixing apparatus using a low heat capacity film, and a process speed. In addition to solving the above-mentioned problems even in an image forming apparatus that has become faster, a high-quality and high-definition image can be obtained even for a wide variety of transfer materials, and the offset phenomenon occurs even when used for a long time. In addition, the present invention provides an image forming toner and an image forming method capable of obtaining a high quality toner image.

[0013]

According to the present invention, there is provided a heating and fixing device for holding and conveying a heated member on which a toner-visible image is formed and applying heat energy and pressure to the heated member. A pressure member having a heat-resistant elastic layer having a thermal conductivity of 0.20 W / m · k or less on a metal core of the heat fixing device to apply pressure to the member to be heated; An image forming toner used in an image forming method of heating and fixing a visible image to a member to be heated, wherein the toner contains a binder resin, a colorant and a wax, and has a hydrophobic metal oxide fine powder as an external additive. The present invention relates to an image forming toner characterized by containing a body.

Further, according to the present invention, there is provided a heat fixing device for nipping and conveying a heated member on which a toner-visible image is formed and applying heat energy and pressure to the heated member. Has a thermal conductivity of 0.2 on the core metal
An image forming method for applying pressure to the member to be heated by a pressing member having a heat-resistant elastic layer of 0 W / m · k or less to heat and fix the toner visible image to the member to be heated.
The toner contains a binder resin, a colorant and a wax,
The present invention relates to an image forming method characterized by containing a hydrophobic metal oxide fine powder as an external additive.

According to the present invention, the above-mentioned object is achieved by using the hydrophobic metal oxide fine particles as an external additive and covering the toner surface with the particles so that a good release of the toner from the pressing member can be achieved. It is considered that sex is particularly expressed. In other words, it has no direct heating element, and is superior to a pressure member used in a temperature change from a state close to room temperature to a temperature close to the fixing temperature (more rapid due to a shortened heating start-up time) depending on the environment and use conditions. It is considered that the releasability was maintained. Further, it is considered that by suppressing the amount of the free external additive, the free external additive attached to the pressure member can be used as a nucleus and the growth of dirt can be suppressed therefrom.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat fixing apparatus according to the present invention has a structure in which a heated member is sandwiched and conveyed between a heating member and a pressing member to apply thermal energy to the heated member. A configuration in which a member to be heated is sandwiched and conveyed between a heat-resistant film and a pressing member arranged so as to be in pressure contact with a heating body via the heat-resistant film to apply thermal energy to the heating member. What has a configuration in which a member to be heated is nipped and conveyed by a fixing roller including a heating element and a pressure roller that is in pressure contact with the fixing roller, and thermal energy is applied to the member to be heated is used.

FIG. 1 is a schematic cross-sectional view of an example of a tensionless film heating type heat fixing apparatus for carrying out the present invention.

Reference numeral 1 denotes a resin-made horizontally long stay, which serves as an inner surface guide member of a film described later. Reference numeral 2 denotes an endless heat-resistant film which is circumscribed to a stay 1 including a heating element 3. The inner peripheral length of the endless heat-resistant film 2 and the outer peripheral length of the stay 1 including the heating element 3 are larger than that of the film 2 by, for example, about 3 mm.
The outer circumference loosely circumscribes the stay 1 including the heating element 3 with a margin.

The film 2 has a thickness of about 100 μm or less in order to reduce the heat capacity and improve the quick start property, and the PTFE has heat resistance, release property, strength, durability and the like. , PFA, FEP monolayer,
Alternatively, polyimide, polyamide, PEEK, PE
An all-layer film in which the outer peripheral surface of S, PPS, or the like is coated with PTFE, PFA, FEP, or the like can be used.

In this embodiment, the heat-resistant film 2
As a result, 1 μm
A layer coated with 0 μm PTFE and having a layer thickness of 60 μm was used.

Reference numeral 3 denotes a heating element, which is formed of, for example, Ag / Pd as a heating element along a substantially central portion of a base made of alumina or the like.
(Silver-palladium) etc. about 10μ thick
m, a width of 1 to 3 mm is formed by screen printing or the like, and a protective layer such as glass or fluororesin is coated thereon. A thermistor for the heating element is provided on the side of the heating element opposite to the fixing film, and the temperature of the heating element 3 is controlled by the temperature detected by the thermistor.

The pressure roller 6 is a rotating body that forms a fixing nip portion with the film interposed between the heating roller 3 and the film and drives the film. The pressure roller 6 is connected to a driving device by a core metal such as iron, stainless steel, or aluminum. Have been. The pressure roller 6 is adapted to rotate by transmitting a driving force from a driving motor of a driving device.

The recording material P as a member to be heated is conveyed and passed through a fixing nip formed between the pressure roller and the heating member with a film interposed therebetween, so that the toner image T is heated and pressed to record. It is designed to be fixed on the material P

Next, the pressure roller according to the present embodiment will be described in detail.

The pressure roller 6 is provided as a heat-resistant elastic layer on an aluminum core bar having an outer diameter of 13 mm connected to a driving device.
Length 240mm, thickness 3mm, thermal conductivity 0.20W / m
-K silicone foam is coated. The measurement of the thermal conductivity is performed by a rapid thermal conductivity meter QMT-5 manufactured by Kyoto Electronics Industry Co., Ltd.
00 was used.

By using the pressure roller having the structure of this embodiment, the heat is not taken away by the pressure roller itself, so that the heating start-up time does not increase. In addition, excessive power consumption associated with it is eliminated.

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-based copolymers such as ene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; 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.

Next, the wax component used in the present invention will be described.

The content of the wax component used in the present invention in the toner is preferably from 0.2 to 100 parts by mass of the binder resin component.
It is preferably 20 parts by mass.

The wax used in the present invention includes the following. For example, examples of the hydrocarbon wax include low-molecular-weight polyethylene, low-molecular-weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, and aliphatic hydrocarbon-based wax such as Fischer-Tropsch wax.

As the wax having a functional group, an oxide of an aliphatic hydrocarbon wax such as an oxidized polyethylene wax; or a block copolymer thereof; a plant such as candelilla wax, carnauba wax, wood wax, jojoba wax; Animal waxes such as beeswax, lanolin, and whale wax; mineral waxes such as ozokerite, ceresin, and petrolactam; waxes mainly containing aliphatic esters such as montanic acid ester wax and caster wax; deoxidized carnauba Examples thereof include those obtained by partially or entirely deoxidizing an aliphatic ester such as a wax. Furthermore, palmitic acid, stearic acid, montanic acid,
Or a saturated straight-chain fatty acid such as a long-chain alkyl carboxylic acid having a longer-chain alkyl group; an unsaturated fatty acid such as brassic acid, eleostearic acid, and vinaric acid; stearyl alcohol, eicosyl alcohol, behenyl alcohol, kaunavir alcohol; Seryl alcohol,
Saturated alcohols such as melisyl alcohol or alkyl alcohols having a longer chain alkyl group; polyhydric alcohols such as sorbitol; aliphatic amides such as linoleic acid amide, oleic acid amide and lauric acid amide;
Saturated aliphatic bisamides such as methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, hexamethylenebisstearic acid amide; ethylenebisoleic acid amide, hexamethylenebisoleic acid amide, N, N'-dithioamide Unsaturated fatty acid amides such as amide adipic acid amide and N, N'-dioleyl sebacic acid amide; aromatic bisamides such as m-xylene bisstearic acid amide and N, N'-distearyl isophthalic acid amide; calcium stearate Aliphatic metal salts such as calcium laurate, zinc stearate and magnesium stearate (commonly referred to as metal soaps); partial esterified products of fatty acids such as behenic acid monoglyceride and polyhydric alcohols; hydrogenating vegetable oils and fats And methyl ester compounds having hydroxyl groups obtained by the the like.

Examples of the wax grafted with a vinyl monomer include a wax obtained by grafting an aliphatic hydrocarbon wax with a vinyl monomer such as styrene or acrylic acid.

The wax preferably used is a polyolefin obtained by radical polymerization of an olefin under high pressure;
Polyolefin obtained by purifying low-molecular-weight by-product obtained during polymerization of high-molecular-weight polyolefin; polyolefin polymerized under low pressure using a catalyst such as Ziegler catalyst or metallocene catalyst; polyolefin polymerized by using radiation, electromagnetic wave or light; paraffin wax , Microcrystalline wax, Fischer-Tropsch wax; synthetic hydrocarbon wax synthesized by the Zintall method, hydrocoll method, Aage method, etc .; synthetic wax using a compound having one carbon atom as a monomer, such as a hydroxyl group, a carboxyl group or an ester group. A hydrocarbon wax having a functional group; a mixture of a hydrocarbon wax and a hydrocarbon wax having a functional group;
Maleate, acrylate, methacrylate,
A wax graft-modified with a vinyl monomer such as maleic anhydride may be used.

These waxes may be obtained by sharpening the molecular weight distribution using a press sweating method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method or a liquid crystal precipitation method, or a low molecular weight solid fatty acid. Also, those from which low-molecular-weight solid alcohols, low-molecular-weight solid compounds, and other impurities have been removed are preferably used.

The wax used in the present invention can be arbitrarily selected from one or more of the above.

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

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 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 coloring agent 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 mass per 100 parts by mass of the resin.

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

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.

The shape of the magnetic material may be an octahedron, a 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, more preferably 0.1 to 0.4 μm.

The amount of the magnetic substance is 3 with respect to 100 parts by mass of the binder resin.
0 to 200 parts by mass, preferably 40 to 200 parts by mass, more preferably 50 to 150 parts by mass. If the amount is less than 30 parts by mass, 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 mass, 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.

As the titanium coupling agent, for example, 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.

In the toner of the present invention, it is preferable to use a charge control agent mixed (internally added) with toner particles or mixed (externally added) with 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.

Further, the following substances are controlled to be positively charged.

Modified products of nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, 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-mentioned 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 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.

The inorganic fine powder used in the present invention may be, for example, a silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, a silane coupling agent, a silane coupling agent having a functional group, for the purpose of hydrophobization. In the present invention, those treated with a treating agent such as an organic silicon compound or an organic titanium compound or a combination of these various treating agents are used.

For example, typical silane coupling agents that can be used at this time are dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzyldimethylchlorosilane. Examples thereof include silane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, and dimethylvinylchlorosilane. The silane coupling agent treatment for the inorganic fine powder is, for example, a dry processing method of reacting a vaporized silane coupling agent to a cloud-like inorganic fine powder by stirring or the like, or dispersing the inorganic fine powder in a solvent. It can be performed by a generally known treatment such as a wet treatment method in which a silane coupling agent is dropped and reacted therein.

In particular, the inorganic fine powder to be contained in the toner of the present invention is preferably further treated at least with silicone oil. The preferred average particle size of the inorganic fine powder after the silicone oil treatment is 0.1 mm.
1 μm or less, more preferably 0.002 to 0.05 μm
(2 to 50 nm). The amount of oil treatment in the silicone oil-treated inorganic fine powder is preferably from 1 to 30% by mass, and particularly preferably from 1 to 20% by mass, based on the inorganic fine powder. A preferable range of the amount of the inorganic fine powder treated with the silicone oil with respect to the toner is 0.3 to 3.0% by mass, and particularly preferably 0.5 to 2% by mass. Further, the oil viscosity of the silicone oil is preferably 1
〜１０10,000 cSt, 50５０1,000 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. Known techniques are used for the method of treating silicone oil. For example, silica fine powder and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or an apparatus for spraying silicone oil on base silica. It may be. Alternatively, it may be prepared by dissolving or dispersing a silicone oil in an appropriate solvent, mixing with a base silica fine powder, and removing the solvent.

Further, the above inorganic fine powder is preferably silica, and in particular, 0.06 g of hydrophobic silica fine powder is placed in a container holding 70 ml of a hydrated methanol solution (60% by volume of methanol and 40% by volume of water). Weighed and added
In a methanol drop transmittance curve prepared by measuring the transmittance of a water-containing methanol solution with light having a wavelength of 780 nm while methanol is dropped into the container at a drop rate of 1.3 ml / min, hydrophobic silica fine powder is added. The hydrated methanol solution has a transmittance of 90% or more at a methanol content of 60 to 72% by volume, and the hydrated methanol solution to which the hydrophobic silica fine powder is added has a transmittance of 90% at a methanol content of 74% by volume.
% Silica (hereinafter referred to as highly hydrophobic silica).

As described above, the highly hydrophobic silica used in the present invention is a fine powder whose surface is uniformly and highly hydrophobicized, and is obtained by externally adding the highly hydrophobic silica to the toner. As a result, it is recognized that the hydrophobicity on the toner surface is also improved, and the charging stability, uniformity, and developability are improved. Hereinafter, the hydrophobic treatment agent for highly hydrophobic silica according to the present invention will be described.

As the hydrophobizing agent for hydrophobizing the raw silica mentioned above, organosilicon compounds are preferably used. As the organosilicon compound used at this time, for example, silicone oil and / or a silane coupling agent can be suitably used.

As the silane coupling agent, for example,
Hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloro Ethyltrichlorosilane, β-
Chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1 ,
3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and 2 per molecule
Examples thereof include dimethylpolysiloxane having up to 12 siloxane units, each of which has a hydroxyl group bonded to one silicon atom in the terminal unit.

In the present invention, silicone oil or silicone varnish can also be suitably used as a hydrophobizing agent for the raw silica. As the silicone oil, those represented by the following general formula (I) are preferable.

[0063]

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Specific examples of the general formula (I) include, for example, dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil,
Chlorophenyl silicone oil, fluorine-modified silicone oil and the like can be mentioned.

In the present invention, a modified silicone oil having a structure represented by the following general formula (II) can be used as the silicone oil.

[0066]

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In the above general formula (II), R ₁ and R ₆ represent a hydrogen atom, an alkyl group, an aryl group or an alkoxy group, R ₂ represents an alkylene group or a phenylene group,
R ₃ represents a compound having a nitrogen-containing heterocyclic ring in its structure, and R ₄ and R ₅ represent a hydrogen atom, an alkyl group, or an aryl group. Also, R ₂ need not be present. However, the above-mentioned alkyl group, aryl group, alkylene group and phenylene group may have an amine, or may have a substituent such as halogen as long as the chargeability is not impaired. m is a number of 1 or more, and n and k are positive numbers including 0. However,
n + k is a positive number of 1 or more.

Among the above structures, the most preferred structure is one in which the number of nitrogen atoms in the side chain containing a nitrogen atom is one or two. Examples of the structure of the nitrogen-containing unsaturated heterocycle are shown below.

[0069]

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Examples of the structure of the nitrogen-containing saturated heterocycle are shown below.

[0071]

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However, the present invention is not limited to the above compound examples, but preferably has a 5-membered or 6-membered heterocyclic ring.

Examples of the derivative include derivatives obtained by introducing a hydrocarbon group, a halogen group, an amino group, a vinyl group, a mercapto group, a methacryl group, a glycidoxy group, a ureido group, and the like into the above compound group. These may be used alone or in combination of two or more.

Examples of the silicone varnish used in the present invention include methyl silicone varnish and phenylmethyl silicone varnish. In the present invention, it is preferable to use methyl silicone varnish. Methyl silicone varnish, a T ³¹ unit, D ³¹ unit, a polymer consisting of M ³¹ units represented by the following structure, and is a three-dimensional polymer containing a T ³¹ units in a large amount.

[0075]

Embedded image

Methyl silicone varnish or phenylmethyl silicone varnish is a substance having a chemical structure represented by the following structural formula (A).

[0077]

Embedded image (In the above formula, R ³¹ represents a methyl group or a phenyl group.)

In the above silicone varnish, in particular, T³¹
The unit provides good thermosetting properties and has a three-dimensional network structure.
Is a valid unit for In the silicone varnish, on
Note T ³¹The unit is 10 to 90 mol%, particularly 30 to 80 mol.
% Is preferably used.

Such a silicone varnish has a hydroxyl group at a terminal or a side chain of a molecular chain, and is cured by a dehydration condensation reaction of the hydroxyl group. Examples of the curing accelerator that can be used to accelerate the curing reaction include fatty acid salts such as zinc, lead, cobalt, and tin; and amines such as triethanolamine and butylamine. Of these, amines can be particularly preferably used.

In order to make the above-mentioned silicone varnish into an amino-modified silicone varnish, the above-mentioned T ³¹ unit, D ³¹
Units, some of the methyl group or a phenyl group present in the M ³¹ units, may be replaced with a group having an amino group. Examples of the group having an amino group include, but are not limited to, those represented by the following structural formula.

[0081]

Embedded image

Known techniques can be used as a method for hydrophobizing the raw silica with these silicone oils or silicone varnishes. For example, a method of mixing silica fine powder and silicone oil or silicone varnish using a mixer, a method of spraying silicone oil or silicone varnish into fine silica powder using a sprayer, or dissolving silicone oil or silicone varnish in a solvent After letting
A method of mixing fine silica powder and the like can be mentioned.

The silicone oil or silicone varnish preferably has a viscosity at 25 ° C. of 10 to 2,000 centistokes, more preferably 30 to 1,500 centistokes. That is, the viscosity is 5
If less than 0 centistokes are used, the level of fusion will decrease. On the other hand, if it exceeds 2,000 centistokes, the level of fusion will decrease.

The viscosity of the silicone oil or silicone varnish was measured using a Visco Tester VT500 (manufactured by Haake).
This was performed using One of several viscosity sensors for VT500 is selected (arbitrary), and a measurement sample is put in a measurement cell for the sensor to measure. The viscosity (pas) indicated on the device was converted to cSt (centistokes).

The form of treatment of the highly hydrophobic silica fine powder used in the present invention may be a treatment with a silane coupling agent or the like, or a silicone oil or silicone varnish alone, or a combination of both treatments. There are cases. As a preferred treatment form among them, a treatment with a silane coupling treatment agent followed by a treatment with a silicone oil or a silicone varnish may be mentioned. Among them, particularly preferred is a form in which after treatment with hexamethylsilazane, treatment with silicone oil is performed.

As a treatment method using a silane coupling agent, a dry treatment in which a cloud of silicic acid fine powder is made by stirring or the like and a vaporized silane coupling agent is reacted, or the fine silicic acid powder is dissolved in a solvent. And a method of wet treatment in which a silane coupling agent is dropped and reacted. A particularly preferred method is
This is a dry method in which a silane coupling agent is brought into contact with cloudy silica fine powder in the presence of steam to cause a reaction.

A known technique is used for the hydrophobic treatment of the original silica surface with silicone oil and / or silicone varnish. For example, silica fine powder and silicone oil are directly mixed with a mixer such as a Henschel mixer. It may be mixed, or by a method of spraying silicone oil onto the raw silica. Alternatively, in a suitable solvent,
The silicone oil may be dissolved or dispersed, mixed with the base silica fine powder, and then the solvent may be removed.

As a method which is favorably used for producing the highly hydrophobic silica fine powder used in the present invention, after treating with a silane coupling agent, spraying silicone oil,
A method of performing heat treatment at 200 ° C. or higher is preferably used.
At this time, the silane coupling agent is used in an amount of 5 to 60 parts by mass, more preferably 1 to 100 parts by mass, based on 100 parts by mass of the raw silica.
It is advisable to add and process in the range of 0 to 50 parts by mass. 5
When the amount is less than the mass part, the drum fusion tends to occur, and when the amount is more than 60 parts by mass, the production may be difficult.

The silicone oil or silicone varnish is used in an amount of 5 parts per 100 parts by mass of the raw silica or the treated silica.
To 40 parts by mass, more preferably 7 to 35 parts by mass. When the amount is less than 5 parts by mass, drum fusion tends to occur, and when the amount is more than 40 parts by mass,
Evils such as image deletion are likely to occur.

Further, the high hydrophobic silica fine powder used in the present invention has a final carbon content of 3.0 to 1
Those in the range of 3.0% by mass, more preferably,
It is preferable to use one in the range of 4.5 to 12.0% by mass. In the present invention, such a carbon content is analyzed by a trace carbon analyzer (EMI manufactured by Horiba, Ltd.).
A-100).

The highly hydrophobic silica fine powder used in the present invention has a number average particle diameter (length average) of 0.1 μm.
m, more preferably 5 to 50 nm.
The highly hydrophobic silica fine powder used in the present invention has a specific surface area of 1 when measured by a nitrogen adsorption method.
It is preferably from 0 to 550 m ² / g, more preferably from 50 to 500 m ² / g.

Further, the highly hydrophobic silica fine powder used in the present invention has a charge amount of -30 to -40 to iron powder.
It is preferable to use a material having a negative triboelectrification of 0 μg / g.
It is preferred to use those of μg / g.

The above-mentioned highly hydrophobic fine silica powder used in the present invention is used in an amount of 0.6 to 100 parts by mass of toner particles.
It is preferable to be used by adding at a ratio of 3.0 parts by mass. That is, when the addition amount is less than 0.6 parts by mass,
It is difficult to obtain a sufficient image density, and if it is more than 3.0 parts by mass, adverse effects such as drum fusion are caused, which is not preferable.

In the toner of the present invention, other additives, for example, lubricant powders such as Teflon (registered trademark) powder, zinc stearate powder, polyvinylidene fluoride powder; Cerium powder,
Abrasives such as silicon carbide powder and 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, and organic and inorganic fine particles of opposite polarity can be used in small amounts as developability improvers.

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.

The toner of the present invention preferably has an external additive amount (free external additive amount) not adhering to the toner surface of 0.20% or less. The amount of this free external additive is 0.20%
If it is larger, the amount of toner that adheres to the pressure member and adheres and grows with the external additive as a nucleus increases, and the contamination of the pressure member is particularly increased.

To prepare the toner according to the present invention, a binder resin, a pigment as a colorant, a dye or a magnetic substance, 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 meat to make the resins compatible with each other and disperse or dissolve the pigment or dye. The toner according to the present invention can be obtained by performing an appropriate classification.

The hydrophobic properties of the hydrophobic silica according to the present invention are as follows:
Selection is made using a methanol drop transmittance curve. Specifically, a methanol drop transmittance curve measured under the following conditions using a powder wettability tester WET-100P manufactured by Resca Co., Ltd. was used as the measuring device.

That is, first, hydrophobic silica fine powder 0.0 as a sample was placed in a container holding 70 ml of a hydrated methanol solution consisting of 60% by volume of methanol and 40% by volume of water.
6 g is precisely weighed and added to prepare a sample liquid for measurement.
Next, 1.3 ml of methanol was added to the sample liquid for measurement.
wavelength 7 while continuously adding at a dropping rate of ml / min.
The transmittance was measured with light of 80 nm.

The amount of release of the external additive according to the present invention is
g was precisely weighed, taken into a mesh having a mesh size of 45 μm, the lower portion of the mesh was suctioned, and the external additive remaining on the mesh was defined as Ag. The amount of free external additive was calculated as follows: A / 50 × 100 (%).

[0101]

Next, the present invention will be described in more detail with reference to examples and comparative examples of the present invention, but this does not limit the present invention in any way. “Parts” means “parts by mass”.

(Polymer Synthesis Example 1) 300 parts of xylene was charged into a four-necked flask, and the inside of the vessel was sufficiently purged with nitrogen while stirring. Then, the temperature was increased to reflux, and styrene 68 was heated under reflux. A mixture of 0.8 parts, 22 parts of n-butyl acrylate, 9.2 parts of monobutyl maleate, and 1.8 parts of di-tert-butyl peroxide was added dropwise over 4 hours, and the mixture was held for 2 hours and polymerized. Was completed and the solvent was removed to obtain a polymer L1. GPC measurement of this polymer L1 showed a peak molecular weight of 15,000.

(Polymer Synthesis Example 2) 180 parts of degassed water and 20 parts of a 2% by mass aqueous solution of polyvinyl alcohol were charged into a four-necked flask, and then 74.9 parts of styrene, 20 parts of n-butyl acrylate, A mixed solution of 5.0 parts of monobutyl maleate and 0.2 parts of 2,2-bis (4,4-di-tert-butylperoxycyclohexyl) propane was added and stirred to form a suspension. After sufficiently replacing the inside of the flask with nitrogen, the temperature was raised to 90 ° C. to initiate polymerization. The polymerization was completed by maintaining the same temperature for 24 hours to obtain a polymer H1.
Thereafter, the polymer H1 was separated by filtration, dried, and then subjected to GPC measurement to find that the peak molecular weight was 800000.

[Synthesis Example of Binder Resin] Polymer L1 and Polymer H
1 in a 70:30 mass ratio in a xylene solution,
Binder resin 1 was obtained.

<Example 1> As the binder resin, 100 parts of the binder resin 1 was used, and magnetic iron oxide (average particle diameter: 0.20 μm) was used.
m, 795.8 kA / m Magnetic field characteristic Hc: 9.2 kA
/ M, σs: 82 Am ² / kg, σr: 11.5 Am ² /
kg), 3 parts of monoazo metal complex (negative charge controlling agent), 3 parts of Fischer-Tropsch wax (maximum endothermic peak 105 ° C), and 3 parts of alcohol wax (maximum endothermic peak 78 ° C). Mix and add 13
The mixture was melt-kneaded with a twin-screw extruder heated to 0 ° C. The obtained kneaded material was cooled, coarsely pulverized by a hammer mill, the coarsely pulverized material was finely pulverized by a jet mill, and the obtained finely pulverized material was classified by an air classifier to obtain a black fine powder (mass average particle size). The diameter was 6.8 μm).

To 100 parts of the obtained black fine powder, 1.2 parts of hydrophobic silica fine powder A described below was added, and the mixture was stirred and mixed at 1700 rpm for 2 minutes with a Henschel mixer, and then 150 mesh. The coarse particles were removed with a sieve to obtain Magnetic Toner 1. The amount of free silica was 0.30%.

The silica A used above was prepared by mixing a water-containing methanol solution (methanol 60% by volume and water 40% by volume).
0.06 g of hydrophobic silica fine powder was precisely weighed and added to a container holding the sample solution to prepare a sample solution for measurement, and methanol was added to the sample solution for measurement at a dropping rate of 1.3 ml / min. A highly hydrophobic silica having the following characteristics in a methanol drop transmittance curve prepared by measuring the transmittance of a water-containing methanol solution with light having a wavelength of 780 nm while dropping the solution into the silica.

[0108]

[Table 1]

<Example 2> A magnetic toner 2 was obtained in the same manner as in Example 1 except that silica fine powder B having hydrophobicity described below was used as the hydrophobic metal oxide fine powder. The amount of free silica was 0.23%.

The silica B used above was prepared by mixing a water-containing methanol solution (methanol 60% by volume and water 40% by volume) with 70%.
To a container holding 0.1 ml of hydrophobic silica fine powder was precisely weighed and added to prepare a sample liquid for measurement, and methanol was added dropwise to the sample liquid for measurement at 1.3 ml / min. It is a highly hydrophobic silica having the following hydrophobic properties in a methanol drop transmittance curve created by measuring the transmittance of a water-containing methanol solution with light having a wavelength of 780 nm while dropping the silica.

[0111]

[Table 2]

Example 3 As a wax component, 6 parts of a polypropylene wax (maximum endothermic peak: 143 ° C.)
Magnetic toner 3 was obtained in the same manner as in Example 1, except that B was used as the hydrophobic metal oxide fine powder. The amount of free silica was 0.25%.

<Example 4> A magnetic toner 4 was obtained in the same manner as in Example 2 except that the externally added hydrophobic metal oxide powder was stirred and mixed at 1700 rpm for 4 minutes using a Henschel mixer. The amount of free silica was 0.17%.

<Comparative Example 1> A magnetic toner 5 was obtained in the same manner as in Example 1 except that the hydrophobic oxide fine powder was not externally added.

[Evaluation] For the toners of the above Examples and Comparative Examples, the components of the fixing device of a commercially available laser beam printer, LaserJet 6L (manufactured by Hewlett-Packard Company) were modified to the configuration shown in FIG. 1, and a printout test was performed. Carried out. The printout speed is 14 sheets per minute (A
4 vertical). The obtained images were evaluated for the following items. These results are summarized in Table 3.

(1) Pressure Roller Dirt The pressure roller dirt can be removed in a low-temperature and low-humidity environment (15 ° C., 10% R).
In H), the degree of toner contamination on the members inside the fixing device and the image at the end of printing out 2,000, 3,000, and 4,000 sheets was visually evaluated. ◎ (excellent): There is no dirt on the pressure roller and no dirt on the image. （(Good): The pressure roller has almost no stain, and the image has no stain. Δ (OK): The pressure roller has dirt, but the image has no dirt. X (poor): The pressure roller has dirt, and the image has dirt.

(2) Image density The image density was 23.0 ° C. and 60% relative humidity.
Initial and 30 g on plain paper (75 g / m ² )
Evaluation was performed by measuring the maintenance of the image density at the end of printing out 00 sheets. The image density was measured using a “Macbeth reflection densitometer” (manufactured by Macbeth Co., Ltd.).
The density of the solid black portion of the millimeter was measured at five points, and the average value was calculated. ◎: 1.40 or more, extremely good ： １: less than 1.40, 1.20 or more, good Δ: less than 1.20, 1.00 or more, good without practical problems ×: less than 1.00, insufficient image density

[0118]

[Table 3]

[0119]

As described above, according to the present invention,
The heat start-up time and power consumption are reduced compared to the on-demand type heat-fixing device using a conventional low-heat-capacity film. While achieving the
It is also possible to obtain a high-quality image.

[0120]

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a configuration of a tensionless film heating type heat fixing device as a first embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stay 2 Heat resistant film 3 Heating body 6 Pressure roller T Toner P Recording material (member to be heated)

Claims (6)

[Claims] 1. A heating and fixing device for holding and heating a member to be heated on which a toner visible image is formed and applying heat energy and pressure to the member to be heated by using a heating and fixing device. Pressure is applied to the member to be heated by a pressure member having a heat-resistant elastic layer having a thermal conductivity of 0.20 W / m · k or less to heat and fix the toner visible image to the member to be heated. An image forming toner used in an image forming method, wherein the toner contains a binder resin, a colorant, and a wax,
An image forming toner comprising a hydrophobic metal oxide fine powder as an external additive. 2. A hydrophobic silica fine powder is externally added as an external additive, and the hydrophobic property of the hydrophobic silica fine powder is measured by using 70 ml of a water-containing methanol solution composed of 60% by volume of methanol and 40% by volume of water. To a sample liquid for measurement prepared by adding 0.06 g of finely weighed hydrophobic silica powder to a container held therein, while adding methanol at a dropping rate of 1.3 ml / min, the transmittance is measured with light having a wavelength of 780 nm. When expressed using a methanol drop transmittance curve prepared by the above method, the hydrophobic property of the hydrophobic silica fine powder is such that the transmittance of the sample liquid for measurement at a methanol content of 60 to 72% by volume is 90% or more. 2. The image forming apparatus according to claim 1, wherein the transmittance of the sample liquid for measurement at a methanol content of 74% by volume is 90% or more. Toner. 3. The toner according to claim 1, wherein the external additive is present on the surface of the toner particles in a state where the external additive adheres to the toner particles and is released.
% Or less, the toner for image formation according to claim 1 or 2. 4. A heating and fixing device for holding and heating a member on which a toner visible image is formed and applying heat energy and pressure to the member to be heated by using a heating and fixing device. Pressure is applied to the member to be heated by a pressure member having a heat-resistant elastic layer having a thermal conductivity of 0.20 W / m · k or less to heat and fix the toner visible image to the member to be heated. In the image forming method, the toner contains a binder resin, a colorant, and a wax, and contains a hydrophobic metal oxide fine powder as an external additive. 5. A toner to which a hydrophobic silica fine powder is externally added as an external additive, wherein the hydrophobic silica fine powder has a hydrophobic property of 60% by volume of methanol and 40% by volume of water. 1.3 ml / mi of methanol was added to a sample liquid for measurement prepared by adding 0.06 g of hydrophobic silica fine powder precisely weighed to a container holding 70 ml of the solution.
When a methanol drop transmittance curve prepared by measuring transmittance with light having a wavelength of 780 nm while adding at a dropping speed of n is used, the hydrophobic property of the hydrophobic silica fine powder has a methanol content of 60 to The transmittance of the sample solution for measurement at 72% by volume is 90% or more, and the transmittance of the sample solution for measurement at a methanol content of 74% by volume is 90% or more. 2. The image forming method according to 1., 6. An external additive is present on the surface of the toner particles in a state of adhering and releasing, and the amount of the released hydrophobic metal oxide fine powder or hydrophobic silica is 0.20% of the total toner mass.
The image forming method according to claim 4, wherein the ratio is not more than%.