JPS63128361A - Capsule toner for heat roller fixing - Google Patents

Abstract

PURPOSE:To obtain excellent low-temp. fixability and offset resistance and to expand a practicable fixable temp. range by incorporating vinyl polymer and wax into meltable core material particles. CONSTITUTION:The vinyl polymer and wax are incorporated into the meltable core material particles of the capsule toner for heat roller fixing formed by providing the meltable core material particles and the shells consisting of a thermoplastic resin provided so to cast the surface of the core material particles. Since the vinyl polymer is incorporated into the core material particles, the viscoelasticity of the toner when melted is adjusted to an adequate size by the characteristic of said vinyl polymer. The transfer of the toner material to a heat roller of the heat roller fixing device is, therefore, hardly generated and the excellent offset resistance is obtd. Since the wax is incorporated into the core material particles, the toner is made meltable at the lower temp. by the characteristic of the wax, i.e., the characteristic that the wax melts at a low temp. The excellent low temp. fixability is thus exhibited particularly under environmental conditions of a low temp. and low humidity. The fixable temp. range is thereby greatly widened.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a capsule toner used for developing electrostatic latent images formed in electrophotography, electrostatic printing, electrostatic recording, etc. This invention relates to a capsule toner for heat roller fixing.

[Background of the invention]

For example, in electrophotography, an electrostatic latent image is usually formed on an electrostatic latent image carrier made of a photoconductive bad light material by charging and exposure, and then this electrostatic latent image is transferred using toner, which is a colored particle. After development, the resulting toner image is transferred to an image support such as transfer paper, and then fixed by heat or pressure to form a visible image.

Conventional methods for fixing toner images include a method in which the toner is heated and melted in a non-contact state using a heater;
Some of the known methods include fixing by dissolving the toner with an organic solvent, fixing by pressurizing the toner, and so-called hot roller fixing method in which a heated roller is brought into direct contact with the toner to melt and press the toner to fix it. The hot roller fixing method is widely used because it has high thermal efficiency and enables high-speed fixing.

However, in recent years, efforts have been made to (a) suppress deterioration caused by overheating of copying machines, and (b) shorten the warm-up time required for the heat roller to rise to a temperature capable of fixing after the heat roller fixing device is activated. (c) To reduce the temperature drop of the heat roller due to the absorption of heat by an image support such as transfer paper, and to enable stable image formation over a number of consecutive times; and (d) copying. From the viewpoint of downsizing machines and improving safety, there is a strong demand to reduce the power consumption of the heater built into the fuser and to enable the fusing process while keeping the heat roller temperature lower. There is.

Therefore, toners are required to (1) be able to achieve good fixing at even lower temperatures, that is, have excellent low-temperature fixing properties, and basically meet the following conditions: is necessary.

(2) In the heat roller fixing method, which is preferred as a fixing method, there is an offset phenomenon, that is, a part of the toner that makes up the image is transferred to the surface of the heat roller during fixing, and this is transferred again to the transfer paper that is sent next. Since the phenomenon of smearing images is likely to occur, toner should be given performance that prevents transfer to a hot roller, that is, anti-offset property.

(3) It should be able to exist stably as a powder without agglomerating under the environmental conditions of use or storage, that is, it should have excellent blocking resistance.

(4) It has good triboelectric charging properties, and the development process, transfer process, and cleaning process can be performed satisfactorily to obtain a clear image without fogging.

(5) The so-called filming phenomenon in which toner substances adhere to the surface of a photoreceptor or carrier particles is suppressed, and images can be stably formed many times.

Conventionally, by using a capsule toner as a toner, the capsule toner is composed of core particles and an outer shell provided to cover the surface of the core particles.
Techniques for improving low-temperature fixability have been proposed. This type of capsule toner uses a low melting point compound or a material with a low glass transition point as core material particles in order to improve meltability at low temperatures. Specifically, the following techniques are disclosed.

■Technology in which core material particles are composed of wax
(Refer to Publication No.-1588).

(2) A technique in which the core particles are made of polyester crosslinked with a polyvalent metal compound (see Japanese Patent Laid-Open No. 174957/1983).

■Technology in which core material particles are composed of low-melting point polyester (
(See Japanese Unexamined Patent Publication No. 176642/1983).

■Technology in which the core material particles are made of a low molecular weight styrene-acrylic resin with a gel content of 20 to 70% (see JP-A-58-176643)
.

■Technology in which the core particles are made of amorphous polyester with a glass transition point of 60°C or lower (Japanese Patent Application Laid-Open No. 58-205161
(see publication).

(2) A technique in which the core material particles are composed of a crosslinked vinyl polymer having a glass transition point of 55°C or less and a gel content of 20% or more (see Japanese Patent Laid-Open No. 58-205161).

■The core material particles have a glass transition point of 60℃ or less and an acid value of 1.
Technology composed of amorphous polyester of 0 to 150 (
(See Japanese Patent Application Laid-Open No. 58-205163).

■Technology in which the core material particles are composed of amorphous polyester and a polyvalent metal compound (Japanese Unexamined Patent Publication No. 58-2051
(See Publication No. 64).

[Problem that the invention seeks to solve]

However, in the above technique (2), when a hot roller fixing method is applied as the fixing method, the offset resistance is considerably poor and the practicality is extremely low.

In addition, although it is recognized that the above technologies (1) to (2) have improved performance under the environmental conditions of normal temperature and normal pressure (e.g., temperature 20°C, relative humidity 60%), compared to the above technology (2), they still have no offset resistance. Therefore, there is a problem that the fixing temperature range in which fixing can be performed without causing an offset phenomenon is narrow, and it is still of low practicality.

Moreover, low temperature and low humidity (e.g. temperature 10℃, relative humidity 40%)
), the temperature of the image support such as transfer paper is low, so the toner tends to be insufficiently melted during fixing, resulting in poorly fixed toner adhering to the rollers that make up the fixing device. There is a problem in that the accumulation contaminates the roller, which causes conveyance failures such as paper jams, and shortens the useful life of the roller.

As described above, the reality is that, depending on the conventional capsule toner, a fully satisfactory capsule toner for heat roller fixation has not yet been obtained.

This is because conventional capsule toners are basically intended for use in pressure fixing methods. That is, the toner is designed to be suitable for the fixing method to which the toner is applied. For example, when a toner designed to be applied to the pressure fixing method is applied to the heat roller fixing method, problems such as offset phenomenon may occur. occurs, and it is not necessarily possible to form a sufficient copy image.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and an object thereof is to have excellent low-temperature fixing properties and offset resistance, and to have a wide practical fixing temperature range, and to have a low-temperature, low-humidity environmental condition. It maintains its excellent low-temperature fixing properties even under low temperatures, and it is possible to fix without staining the rollers that make up the fixing device.It also has excellent blocking resistance, frictional charging properties, and filming resistance. To provide a capsule toner for hot roller fixing which can stably form a clear image without capri over a large number of times.

[Means for solving problems]

The capsule toner for heat roller fixing of the present invention includes meltable core particles and an outer shell made of a thermoplastic resin provided to cover the surface of the core particles. It is characterized in that the meltable core material particles contain a vinyl polymer and wax.

[Function and effect of the invention]

According to the capsule toner for hot roller fixing of the present invention, since the core material particles contain a vinyl polymer, the viscoelasticity of the toner when melted is adjusted to an appropriate level due to the characteristics of the vinyl polymer. It is difficult to transfer the toner substance to the heat roller of the heat roller fixing device, and it has excellent offset resistance.Moreover, since wax is contained in the core material particles,
Due to the characteristics of this wax, that is, the ability to melt efficiently at low temperatures, the toner can be melted at lower temperatures, and exhibits excellent low-temperature fixing properties, particularly under low-temperature, low-humidity environmental conditions. As described above, since the toner can be fixed at a lower temperature without causing the offset phenomenon, the fixable temperature range is sufficiently widened, and it is possible to obtain a toner which is extremely excellent in practical use.

Since wax has the property of being hard at temperatures below its melting point, it greatly contributes to the hardening of the core material particles.
The toner has excellent durability, and since wax has excellent releasability in its molten state, the transfer of toner material to the heat roller is more reliably suppressed, and as a result, the heat of the heat roller fuser is suppressed. There is little dirt on the roller, and images can be formed successfully many times.

Since the core particles are covered with an outer shell made of thermoplastic resin, the outer shell provides excellent blocking resistance, good triboelectric charging properties, cleaning properties, and excellent anti-filming properties. .

[Specific structure of the invention]

Hereinafter, a specific configuration of the present invention will be explained.

In the present invention, a capsule toner for heat roller fixation is basically constructed by covering the surface of core material particles containing a vinyl polymer and wax with an outer shell made of a thermoplastic resin.

The glass transition point 'rg of the vinyl polymer is 40 to 7.
The temperature is preferably 0°C, particularly preferably 40 to 60°C. By selecting a material having a glass transition point 'rg within such a range, even better low temperature fixing properties, anti-offset properties, and durability can be obtained. That is, when the glass transition point Tg is too small, the core material particles become soft and the offset resistance and durability may be reduced, while when the glass transition point "rg is too large, the low-temperature fixing properties are reduced. Therefore, sufficient low-temperature fixability may not be obtained, particularly under environmental conditions of low temperature and low humidity (for example, a temperature of 10° C. and a relative humidity of 40%).

In the present invention, the glass transition point Tg refers to the extension line of the baseline below the glass transition point when measured using a differential scanning calorimeter [low temperature DSCJ (manufactured by Rigaku Denki Co., Ltd.) at a heating rate of 10°C/min]. This is the temperature at the intersection of the curve and the tangent line showing the maximum slope from the rising edge of the peak to the top of the peak.

In the present invention, the core material particles may contain other components in addition to the vinyl polymer and wax, and the vinyl polymer accounts for at least 50% by weight or more in the core material particles. It is preferable that the content is as follows. If this ratio is too small, the offset resistance and durability of the capsule toner may deteriorate.

Further, the vinyl polymer has a weight average molecular weight Mw
The value of the ratio Mw/Mn between the number average molecular weight Mn and the number average molecular weight Mn is preferably 3.5 or more, particularly preferably 5 or more. By selecting a toner having a ratio Mw/Mn of 3.5 or more, particularly 5 or more, the capsule toner can have even better offset resistance and mechanical durability. In particular, a styrene resin having the ratio Mw/Mn of 3.5 or more can be preferably used. Here, the styrene resin refers to a polymer or copolymer of one or more styrene monomers, or a copolymer of a styrenic monomer and a vinyl monomer other than the styrene monomer. It is a polymer.

Examples of the styrenic monomer for obtaining such a styrenic resin include styrene, 0-methylstyrene, m-
Methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n -Octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3゜4-dichlorostyrene, etc. be able to.

These monomers may be used alone or in combination.

In addition, vinyl monomers other than styrene monomers for obtaining styrenic resins include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, acrylic n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate , propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, methacrylate α-methylene aliphatic monocarboxylic acids and their esters such as diethylaminoethyl acid; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide; vinyl acetate, vinyl butyrate,
Vinyl esters such as vinyl benzoate; Vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; Vinyl ketones such as vinyl methyl ketone; Dienes such as butadiene and isoprene; Unsaturated carboxylic acids such as maleic acid and fumaric acid; Others can be mentioned. These monomers may be used alone or in combination.

In the above, weight average molecular weight and number average molecular weight M
The value of n can be determined by various methods, and there are slight differences depending on the measurement method, but in the present invention, it is determined by the following measurement method.

That is, the weight average molecular weight h, number average molecular weight Mn, and peak molecular weight are measured by gel permeation chromatography (GPC) under the conditions described below. At a temperature of 40° C., a solvent (tetrahydrofuran) is flowed at a flow rate of 1.2 −/min, and a sample solution of 3 mg of tetrahydrofuran with a concentration of 0.2 g/20 − as a sample weight is injected for measurement. When measuring the molecular weight of a sample, select measurement conditions in which the molecular weight of the sample falls within a range where the logarithm of the molecular weight and the count number of the calibration curve prepared using several types of monodispersed polystyrene standard samples are linear. .

The reliability of the measurement results is based on the NB5706 boristyrene standard sample (weight average molecular weight M
w=28.8X10', number average molecular weight Mn=13.
7×10' + Mw/ Mn-2,11) ratio Mw/
This is confirmed by checking that the Mn value is 2.11±0.10.

Moreover, any column may be used as the GPCO column as long as it satisfies the above conditions. Specifically, for example, TSK-GEL, GMHa (manufactured by Toyo Soda Co., Ltd.), etc. can be used.

Further, the vinyl polymer is a vinyl polymer containing a high molecular weight polymer component and a low molecular weight polymer component, and has at least two maximum values in a molecular weight distribution curve determined by gel permeation chromatography. Preferably. As such a vinyl polymer, a styrene-acrylic copolymer is particularly preferred.

In such vinyl polymers, the high molecular weight polymer component has a peak molecular weight of 50,000 to 2,000,000.
The peak molecular weight of the low molecular weight polymer component is preferably within the range of 1,000 to 40,000, and furthermore, the vinyl polymer has at least two Preferably, it has a maximum value.

It should be noted that some of these vinyl polymers have a peak molecular weight of 4.
A so-called intermediate molecular weight polymer component of 0,000 to 50,000 may be included.

When the peak molecular weight of the high molecular weight polymer component is too small, or when the peak molecular weight of the low molecular weight polymer component is too small, the offset resistance and mechanical durability of the toner may decrease; When the peak molecular weight of the combined component is too high, or when the peak molecular weight of the low molecular weight polymer component is too high, the vinyl polymer becomes too tough, resulting in poor low-temperature fixing properties, or in the crushing process in the toner manufacturing process. Grinding may be difficult.

The proportion of the high molecular weight polymer component is preferably 5 to 60 parts by weight, particularly preferably 10 to 50 parts by weight, based on 100 parts by weight of the low molecular weight polymer component. By selecting within such a preferable range, low-temperature fixing properties and offset resistance become even more excellent.

Such a vinyl polymer can be produced, for example, by the following method.

(1) A method in which a high molecular weight polymer component and a low molecular weight polymer component are produced individually and melt-kneaded, or they are dissolved in a common solvent and mixed.

(2) A method of performing polymerization in the presence of one polymer component to obtain the other polymer component.

In addition, the vinyl polymer varies depending on its composition, and although it cannot be generally specified, it is generally
It is preferable that the softening point Tsp according to the ring and ball method specified in K2531-1960 is 80 to 150°C.

In the present invention, wax is contained as an essential component in the core material particles together with the vinyl polymer. Due to the presence of this wax, when the toner is fixed by the heat roller, the toner contacts the heat roller and melts quickly, and a thin film of wax is formed at the interface with the heat roller, and as a result, the toner substance is transferred to the heat roller. The transfer and adhesion of can be effectively prevented, and the service life of the heat roller can be further improved.

The wax is preferably one that melts sharply at its melting point Tmp and has a low melting point Tmp. In addition, in order to melt sharply and have a low viscosity, the melt viscosity at 120°C must be 5.000 cp.
s or less, and the number average molecular weight Mn is preferably 10,000 or less.

The melting point Tmp of the wax is preferably 40 to 120°C, particularly preferably 50 to 110°C. When the melting point Tmp of the wax is too high, low-temperature fixing properties may be reduced, while when the melting point Tn+p is too small, anti-offset properties and durability may be reduced.

Note that the melting point Tmp of wax is determined by differential scanning calorimetry (
DSC).

In other words, the number 1111! sample at a constant heating rate (10
The melting peak value when heated at ℃/m1n) is the melting point Tm
Let it be p.

Examples of waxes that can be used in the present invention include solid paraffin wax, micro wax, rice wax, amide wax, fatty acid wax, fatty acid metal salt wax, fatty acid ester wax, and partially saponified fatty acid ester wax. , silicone varnish, higher alcohol, carnauba wax, etc.

The content of wax in the core material particles is preferably 5 to 50% by weight, particularly preferably 5 to 45% by weight. If the wax content is too small, the low-temperature fixing properties may be reduced, while if the wax content is too large, the offset resistance may be reduced.

In the present invention, in addition to the vinyl polymer and wax, other resins may be mixed in the core material particles as necessary. Examples of such other resins include polyester resins, epoxy resins, and polyurethane resins.

In the present invention, the surface of the core particle is covered with an outer shell made of a thermoplastic resin, and as such a thermoplastic resin, those conventionally used as resins for toners can be used. Specific examples include vinyl polymers, polyester resins, epoxy resins, and polyurethane resins. Among these, vinyl polymers and polyester resins are particularly preferred, and specific examples include styrene-n-butyl acrylate copolymer, styrene-methyl methacrylate-n20-butyl methacrylate copolymer, and terephthalic acid-bisphenol A propylene. Examples include oxide condensates.

The thermoplastic resin forming the outer shell has a glass transition point Tg
It is preferable that the temperature is 50°C or higher. Glass transition point Tg
When is too small, the blocking resistance of the capsule toner may deteriorate.

The thermoplastic resin forming the outer shell has a ratio Mw/Mn of its weight average molecular weight Mw to number average molecular weight Mn of 7.
It is preferable that it is 0 or more. When the value of this ratio Mw/Mn is too small, the offset resistance of the capsule toner may deteriorate.

The capsule toner of the present invention may optionally contain a colorant,
So-called toner components such as a charge control agent and a fixing property improving aid may be added. These toner components may be contained in the core particles or in the outer shell.

Capsule toner also contains additives such as fluidity improvers, abrasives, and cleanability improvers, which are adhered to the outer shell or are held by being driven into the outer shell. Good too.

Examples of colorants include carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green offsalate,
Mention may be made of lamp black, rose bengal, mixtures thereof, and others.

Examples of the charge control agent include metal complex dyes, nigrosine dyes, and ammonium salt compounds.

Examples of the fixing property improving aid include polyolefins such as polyethylene and polypropylene. In particular, polyolefins having a softening point Tsp of 70 to 150°C by the ring and ball method are preferable, and furthermore, the softening point Ts
Polyolefins having p of 120 to 150°C are preferred.

Inorganic fine particles can be preferably used as the fluidity improver and abrasive. The primary particle diameter of the inorganic fine particles is preferably 51μ to 2μ, particularly 51p to 2μ.
Preferably 500 xp.

In addition, the specific surface area according to the BET method is 20 to 500 m"
/g is preferable. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight, particularly preferably 0.01 to 2.0% by weight of the capsule toner. Specific examples of inorganic fine particles include silica,
Alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony dioxide, oxide Magnesium, zirconium oxide,
Examples include barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

Particularly preferred is fine silica powder.

The silica fine powder is a fine powder having an St -0-5i bond, and may be produced by either a dry method or a wet method. In addition to anhydrous silicon dioxide, aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, zinc silicate, etc. may be used, but those containing 85% by weight or more of SiO2 are preferred. As specific examples of fine silica powder, there are various commercially available products, but those having a hydrophobic group on the surface of the fine particles are particularly preferable, such as [Aerosil R-972J, "Aerosil R-974J, , [
Aerosil R-812J (manufactured by Aerosil), [
Taranox 500J (manufactured by Talco) and the like can be preferably used. In addition to these, fine silica powder whose surface has been treated with a silane coupling agent, a titanium coupling agent, silicone oil, a silicone oil having an amine in its side chain, etc. can be used.

Examples of the cleaning performance improver include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, and polymer particles such as methyl methacrylate particles and styrene particles.

Further, in the case of producing a magnetic toner, fine particles of magnetic material may be contained in one or both of the core material particles and the outer shell.

Such magnetic materials include ferrite, magnetite, iron, nickel, cobalt, and other ferromagnetic metals or alloys, compounds containing these elements, and compounds that do not contain ferromagnetic elements but can be treated with appropriate heat treatment. Mention may be made of alloys which become ferromagnetic, such as alloys of the type called Heusler alloys containing manganese and copper, such as manganese-copper-aluminum, manganese-copper-tin, chromium dioxide, and the like. The magnetic material is preferably contained in the form of a fine powder having an average particle size of 0.1 to 1 μm and uniformly dispersed. And the content ratio of magnetic material is
The amount is preferably 10 to 70 parts by weight, particularly preferably 20 to 50 parts by weight, based on 100 parts by weight of the capsule toner.

In the present invention, core material particles can be manufactured, for example, by the following method.

(1) The above-mentioned vinyl polymer and wax for forming the core material particles and toner components such as a colorant used as necessary are melt-kneaded using, for example, an extruder, and after cooling, finely kneaded using a jet mill or the like. A method of pulverizing and classifying the pulverized material to obtain core material particles of the desired particle size.

(2) The above-mentioned vinyl polymer and wax for forming the core material particles and toner components such as colorants used as necessary are melt-kneaded using, for example, an extruder, and then sprayed in the molten state. A method of obtaining core material particles of a desired particle size by spraying with a dryer or the like.

(3) The vinyl polymer and wax constituting the core material particles and toner components such as colorants used as necessary are melt-kneaded using, for example, an extruder, and then immersed in a liquid in a molten state. A method of obtaining core material particles of a desired particle size by dispersing them.

In addition, in the present invention, as a method for forming an outer shell on the surface of the core particle, a coating solution in which a thermoplastic resin for forming the outer shell is dissolved or dispersed in a solvent is used, for example, by dipping, spray drying, etc. A coating layer is formed by coating the surface of core material particles using a method such as a method or a fluidized bed method, heating and drying to volatilize the solvent, and curing the coated layer during or after drying. I can do it. For example, when forming a coating layer by a fluidized bed method, the core particles are raised to an equilibrium height by a rising pressurized gas flow in a fluidized bed device, and then the core particles fall again. The coating solution can be sprayed and this spraying can be repeated to form the shell.

The capsule toner of the present invention may be combined with a carrier to form a two-component developer, or may be used as a magnetic capsule toner containing a magnetic substance to form a one-component developer consisting only of the magnetic capsule toner. It may be something that does.

The capsule toner of the present invention is a capsule toner for heat roller fixation, and is used to form an image, for example, in the following manner. That is, in electrophotography, an electrostatic latent image formed on a photoreceptor, which is a latent image carrier, is developed with a two-component developer or a one-component developer configured using the capsule toner of the present invention, The obtained toner image is electrostatically transferred, for example, to a support made of paper or the like, and then the transferred toner is fixed by a hot roller fixing method, thereby forming a fixed image.

A heat roller fixing device used in a heat roller fixing method is usually composed of a heat roller, a pressure roller disposed in opposition to the heat roller, and a heat source.

Further, a cleaning roller is disposed opposite to the heat roller as necessary. While maintaining the temperature of the heat roller within a certain range using a heating source, the toner is brought into direct contact with the heat roller by passing the toner-transferred support between the heat roller and the pressure roller. is heat-fixed to the support.

Further, the material of the heat roller is preferably a fluorine-based material or a silicone-based material, and the durability of the heat roller can be significantly improved due to the synergistic effect with the capsule toner according to the present invention.

[Specific examples]

Although specific examples of the present invention will be described below, the present invention is not limited to these examples.

<Example 1> (1) Production of core material particles 50 parts by weight of styrene, 0 parts by weight of methyl methacrylate,
A composition of a high molecular weight polymer component consisting of 40 parts by weight of n-butyl acrylate and 0.3 parts by weight of benzoyl peroxide was gradually added dropwise to 200 parts by weight of toluene at reflux temperature to carry out solution polymerization. I got it.

Next, 500 g of toluene was added to the solution of the high molecular weight polymer component.
After adding 125 parts by weight of styrene, 25 parts by weight of methyl methacrylate, n
A composition of a low molecular weight polymer component consisting of 25 parts by weight of -butyl methacrylate, 25 parts by weight of α-methylstyrene, and 17.5 parts by weight of benzoyl peroxide was gradually added dropwise to carry out solution polymerization.

Next, the toluene solvent was distilled off under reduced pressure to obtain a vinyl polymer consisting of a high molecular weight polymer component and a low molecular weight polymer component. This is referred to as "vinyl polymer 1".

This vinyl polymer 1 has gel permeation.
2.7 in the molecular weight distribution curve by chromatography
It has maximum values at X 105 and 7.4 X 10'', respectively, weight average molecular weight is 1.2
It is ℃.

100 parts by weight of the vinyl polymer 1, 10 parts by weight of carbon blank [Mogul LJ (manufactured by Cabot), and paraffin wax "Sasol Wasox H1"
(Melting point T mp: 10B°C, manufactured by Sasol Corporation) in a V-type blender, melt-kneaded with two rolls, cooled, coarsely crushed with a hammer mill, and further finely crushed with a jet mill. After that, the mixture was classified using an air classifier to obtain core particles having a particle size of 1 to 30 nm.

This is referred to as "core material particle 1."

(2) Production of outer shell Styrene-methyl methacrylate-acrylic acid-n-butyl acrylate copolymer (copolymerization weight ratio - 65:15
:5 :15) emulsified dispersion (solid content: 10% by weight) 5
After adding 300 parts by weight of the core material particles 1 to 00 parts by weight and sufficiently dispersing them, spray drying was performed at an inlet temperature of 180°C and an outlet temperature of 60°C to coat the surface of the core material particles with the above copolymer. A capsule toner powder was obtained.

To 50 parts by weight of this capsule toner powder, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972J (manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain a capsule toner according to the present invention. Let it be "toner 1".

(3) Preparation of developer 950 of a resin-coated carrier prepared by coating the surface of copper-zinc ferrite particles with a styrene-methyl methacrylate copolymer (copolymerization weight ratio -70:30) to the above weight part of toner 1. A developer was prepared by mixing parts by weight. This will be referred to as "Developer 1".

(4) Actual photocopying test Using the above developer 1, an electrophotographic copying machine rU-Bix
1600J (manufactured by Konishiroku Photo Industry Co., Ltd.) to form and develop an electrostatic latent image, and conduct a live copying test in which the resulting toner image was transferred onto transfer paper and fixed by a heated roller fixing device to form a copy image. The following items were evaluated.

■Minimum fixing temperature After creating an unfixed image using the above copying machine, a heat roller with a diameter of 30φ whose surface layer is made of Teflon (polytetrafluoroethylene manufactured by DuPont) and a silicone rubber surface layer rKE-1300RTVJ (Shin-Etsu Chemical A toner image of the sample toner was transferred onto a 64 g/m'' transfer paper using a heat roller fixing device consisting of a pressure roller (manufactured by Kogyo Co., Ltd.) at a linear speed of 70 μ/sec and a linear pressure of 0. ．．
8kg/C111% -1-tube width 4.9nn
Raise the temperature in steps of 5 degrees Celsius within a range of 40 degrees Celsius, repeat at each temperature, apply Kimwibe rubbing to the formed fixed image, and then set the lowest temperature for a fixed image that shows sufficient rubbing resistance. The lowest fixing temperature was set. Note that the heat roller fixing device used here does not have a silicone oil supply mechanism. In addition, the environmental conditions are normal temperature and normal pressure (temperature 2
0℃, relative humidity 60%) and low temperature and low humidity (temperature 10℃).

The Mw was set at 2 times (relative humidity: 40%).

■Offset Occurrence Temperature The offset occurrence temperature is measured in accordance with the above minimum fixing temperature measurement, but after creating an unfixed image with the above copier,
The toner image is transferred and fixed using the heat roller fixing device described above, and then a blank transfer paper is sent to the heat roller fixing device under the same conditions and visually observed to see if toner stains occur on it. Operate 1. The set temperature of the heat roller of the heat roller fixing device was repeatedly raised in sequence, and the lowest set temperature at which toner staining occurred was taken as the offset generation temperature. In addition, the environmental conditions are normal temperature and normal pressure (temperature 2
Two Mws were used: one at 0° C., relative humidity 60%) and one at low temperature and low humidity (temperature 10° C., relative humidity 40%).

(2) Fixable Temperature Range The difference between the offset generation temperature and the minimum fixing temperature measured as described above was defined as the fixable temperature range.

■Blocking resistance The blocking resistance test was conducted at a temperature of 55℃ and a relative humidity of 6.
The toner was left under 0% environmental conditions for one day and judged based on whether or not agglomerates were formed in the toner. If no agglomerates were observed, it was marked "○", and if agglomerates were observed, it was marked "x". And so.

■Environmental conditions are low temperature and low humidity (temperature 10℃, relative humidity 40%)
Durability of the fuser under low temperature and low humidity (temperature 10°C, relative humidity 40%)
The setting temperature of the fixing device of J is 10 times higher than the above minimum fixing temperature.
We conducted many live-action tests with the temperature set at a high temperature of ℃, and found that the heat roller was dirty, the cleaning roller for the heat roller was dirty, the pressure roller was dirty, offset occurred,
The durability of the fixing device was evaluated based on the occurrence of paper jams and stains on the back side of the transfer paper.

■Fog “Sakura Densitometer” (manufactured by Konishiroku Photo Industry Co., Ltd.)
The determination was made by measuring the relative density of a white background portion with a document density of 0.0 with respect to the developed image. Note that the white background reflection density was set to 0.0. For evaluation, if the relative concentration is less than 0.01, it is marked as "○", and if it is 0.01 or more and less than 0.03, it is marked as "○".
Cases of 0.03 or more were marked as "x".

(2) Image Quality A live copying test was conducted 30,000 times continuously using the above-mentioned copying machine, and the sharpness of the copied image at the initial stage of image formation and at the final stage of image formation was examined. The evaluation was rated "○" if it was good, "△" if it was not good but still at a practical level, and "x" if it was inferior and had problems in practical use.

■Cleanability A live copying test was conducted 30,000 times using the above-mentioned copying machine, and each time the number of copies reached 5,000, the surface of the photoreceptor was visually observed after being cleaned by the cleaning blade. Judgment was made based on the presence or absence of deposits. The evaluation was rated "○" if it was good, "Δ" if it was not good but still at a practical level, and "x" if it was inferior and had problems in practical use.

■ Filming resistance After carrying out 30,000 continuous tests using the copying machine mentioned above, the surface of the carrier particles, the surface of the photoreceptor, and the cleaning blade were each observed using an electron microscope or visually, and the presence or absence of adhesion was determined by I judged it. When no deposits were observed, it was marked as "○", when some deposits were observed, it was marked as "△", and when a considerable amount of deposits were observed, it was marked as "x".

The above results are shown in Table 1 below.

<Example 2> (1) Production of core material particles In Example 1, the composition of the high molecular weight polymer component was 50 parts by weight of styrene, 10 parts by weight of methyl methacrylate, 40 parts by weight of 2-ethylhexyl acrylate, and benzoyl. Using a composition of high molecular weight polymer component consisting of 0.3 parts by weight of peroxide, 140 parts by weight of styrene, 25 parts by weight of methyl methacrylate, and 25 parts by weight of 2-ethylhexyl acrylate as a composition of low molecular weight polymer components. , 10 parts by weight of α-methylstyrene, and 20 parts by weight of benzoyl peroxide. A vinyl polymer consisting of the following was obtained. This is referred to as "vinyl polymer 2."

This vinyl polymer 2 contains gel, vermutation,
2.7 in the molecular weight distribution curve by chromatography
It has maximum values at X 10S and 9.2 X 10'', respectively, and the weight average molecular weight Mw is 1.4 X 105,
The ratio Mw/Mn value is 14.3, the glass transition point Tg is 48
It is ℃.

100 parts by weight of the vinyl polymer 2, 10 parts by weight of carbon black "Mogul LJ (manufactured by Cabot), and solid paraffin (melting point 'I'mp: 62-6
5 parts by weight of polypropylene [Viscol 66
Core material particles were obtained in the same manner as in Example 1 using 3 parts by weight of 0PJ (softening point Tsp: 130°C, manufactured by Sanyo Chemical Industries, Ltd.). This will be referred to as "core material particle 2."

(2) Production of outer shell Capsule toner powder was obtained in the same manner as in Example 1, except that the core particles 2 described above were used.

A capsule toner according to the present invention was obtained in the same manner as in Example 1 except that this capsule toner powder was used. This is 1
"Toner 2".

(3) Preparation of developer A developer was prepared in the same manner as in Example 1, except that the above Toner 2 was used. This will be referred to as "Developer 2".

(4) Photo-photography test A photo-photography test was conducted in the same manner as in Example 1, except that the developer 2 described above was used and the number of image formations was 50,000 times, and each item was evaluated. The results are also shown in Table 1 below.

<Example 3> (1) Production of core material particles In Example 1, fatty acid ester wax "Wax E" (melting point Tmp
Core material particles were obtained in the same manner as in Example 1, except that 10 parts by weight of polyethylene (softening point Tsp: 135°C) were used. This will be referred to as "core material particle 3."

(2) Production of outer shell A capsule toner powder was obtained in the same manner as in Example 1, except that the core particles 3 described above were used.

A capsule toner according to the present invention was obtained in the same manner as in Example 1 except that this capsule toner powder was used. this"
"Toner 3".

(3) Preparation of developer A developer was prepared in the same manner as in Example 1, except that the above Toner 3 was used. This will be referred to as "Developer 3".

(4) Photo-photography test A photo-photography test was conducted in the same manner as in Example 1, except that the developer 3 described above was used and the number of image formations was changed to 50,000 times, and each item was evaluated. The results are also shown in Table 1 below.

<Comparative Example 1> A developer was prepared in the same manner as in Example 1, except that the core material particles 1 obtained in the same manner as in the example were used as a toner (hereinafter referred to as "Comparative Toner 1"). Using this developer, a photographic test was conducted in the same manner as in Example 1, and each item was evaluated. The results are also shown in Table 1 below.

<Comparative Example 2> Styrene-n-butyl acrylate copolymer (copolymerization weight ratio -70: 30. Glass transition point Tg = 47°C 9 Weight average molecular weight Mw = 6.4X10', Number average molecular weight M
n = 2.1 x LO' + 1 maximum value in the molecular weight distribution curve) and 10 parts by weight of carbon black "Mogal LJ (manufactured by Cabo Soto),
Core material particles were obtained by processing in the same manner as in Example 1.

A comparative capsule toner (hereinafter referred to as "comparative toner 2") was produced in the same manner as in Example 1 except that these core particles were used.

) obtained.

A developer was prepared using this comparative toner 2 in the same manner as in Example 1, and a photographic test was conducted using this developer in the same manner as in Example 1, and each item was evaluated. The results are also shown in Table 1 below.

<Comparative Example 3> Core material particles were obtained in the same manner as in Example 1, except that paraffin wax was not used.

A comparative capsule toner (hereinafter referred to as "comparative toner 3") was produced in the same manner as in Example 1 except that these core particles were used.

) was obtained.

A developer was prepared using this comparative toner 3 in the same manner as in Example 1, and a photographic test was conducted using this developer in the same manner as in Example 1, and each item was evaluated. The results are also shown in Table 1 below.

As understood from the results in Table 1, toner 1 of the present invention
-3, all have excellent low temperature fixing properties,
In particular, it has sufficient low-temperature fixability even under low-temperature, low-humidity environmental conditions, has excellent offset resistance, and has a wide fixable temperature range of 100 to 105°C. In addition, the anti-blocking property is good, and even after 30,000 times of live copying tests, clear copied images without fogging can be obtained.
Furthermore, the cleaning properties and filming resistance are also good. Furthermore, even under low temperature and low humidity environmental conditions, there is no dirt on the heated roller, and the image forming process can be carried out smoothly without problems such as paper jams. Even after 50,000 cycles, the heat roller does not become dirty, and the durability of the heat roller fixing device can be significantly improved. Further, by performing fixing using a heat roller made of fluororesin, the durability of the heat roller fixing device can be further improved.

On the other hand, Comparative Toner 1 does not have an outer shell, so it has sufficient low-temperature fixing properties, but its anti-blocking properties are poor, resulting in poor triboelectric charging properties with the carrier. The copied image becomes foggy and unclear. In addition, the cleaning properties and filming resistance are poor, and the durability is low. In addition, under low temperature and low humidity environmental conditions, heat roller stains occur significantly.
As a result, paper jams occur, making it difficult to perform the image forming process smoothly.

In addition, in Comparative Toner 2, the core particles do not contain wax, so the low-temperature fixing properties are poor, and especially under low-temperature, low-humidity environmental conditions, the low-temperature fixing properties are extremely poor, resulting in poor fixing. The heat roller becomes extremely dirty due to the toner, and as a result, problems such as clogging occur at an early stage, resulting in low durability.

In addition, in Comparative Toner 3, since no wax is contained in the core particles, low-temperature fixing properties are poor, and especially under low-temperature, low-humidity environmental conditions, low-temperature fixing properties are extremely poor, resulting in poor fixing. The heat roller was extremely dirty due to toner, and the live-action test was only 10
Paper jams occur after 00 cycles and the durability is low.

Claims (1)

[Scope of Claims] 1) A capsule toner for hot roller fixing comprising meltable core particles and an outer shell made of a thermoplastic resin provided to cover the surface of the core particles, comprising: A capsule toner for heat roller fixing, characterized in that material particles contain a vinyl polymer and wax. 2) The heat roller according to claim 1, wherein the vinyl polymer has a ratio Mw/Mn of weight average molecular weight Mw to number average molecular weight Mn of 3.5 or more. Capsule toner for fixing. 3) A patent characterized in that the vinyl polymer contains a low molecular weight polymer component and a high molecular weight polymer component, and has at least two maximum values in a molecular weight distribution curve determined by gel permeation chromatography. A capsule toner for heat roller fixing according to claim 1. 4) The peak molecular weight of the low molecular weight polymer component is 1,000 or more
40,000, and the peak molecular weight of the high molecular weight polymer component is within the range of 50,000 to 2,000,000. capsule toner. 5) Glass transition point Tg of vinyl polymer is 40 to 70°C
The capsule toner for heat roller fixing according to claim 1, characterized in that: 6) The proportion of vinyl polymer in the meltable core material particles is 5
The capsule toner for heat roller fixing according to claim 1, characterized in that the content is 0% by weight or more. 7) The capsule toner for heat roller fixing according to claim 1, wherein the wax has a melting point of 40 to 120°C. 8) Claim 1, characterized in that the thermoplastic resin forming the outer shell has a glass transition point Tg of 50°C or higher.
Capsule toner for heat roller fixing as described in .