JP2916838B2 - Toner for developing electrostatic images - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer used for electrophotography, electrostatic printing, and magnetic recording.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
Many methods are known as described in Japanese Patent Publication No. JP-A-Heisei, 43-24878 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. Forming and then developing the latent image with toner,
After transferring the toner image to a transfer material such as paper as necessary,
The toner is fixed by heating, pressure, heat and pressure, or solvent vapor to obtain a copy, and the toner remaining on the photoreceptor without being transferred is cleaned by various methods, and the above steps are repeated. In recent years, such copying apparatuses have begun to be used not only as office work copying machines for simply copying original manuscripts, but also as printers for computer output or personal copying for individuals.

[0003] For this reason, smaller, lighter, faster, and more reliable devices have been strictly pursued, and machines have become simpler in various aspects. As a result, the performance required of the toner has become higher, and if the performance of the toner cannot be improved, a better machine cannot be realized.

For example, various methods and apparatuses have been developed for fixing a toner image to a sheet such as paper. For example, there are a compression heating method using a heat roller and a heat fixing method in which a heating member is brought into close contact with a heating member via a film.

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

Conventionally, for the purpose of preventing the toner from adhering to the surface of the fixing roller, for example, the roller surface is formed of a material having excellent releasability with respect to the toner, such as silicone rubber or a fluorine-based resin. In order to prevent the roller surface from being fatigued, the roller surface is coated with a thin film of a liquid having good releasability such as silicone oil. However, this method is extremely effective in preventing toner offset, but has a problem that a fixing device is complicated because a device for supplying an anti-offset liquid is required. .

[0007] This is in the opposite direction of miniaturization and weight reduction, and moreover, silicone oil and the like may evaporate due to heat and contaminate the inside of the machine. Therefore, instead of using a silicone oil supply device, instead of supplying the anti-offset liquid during heating from the toner, a method of adding a release agent such as low molecular weight polyethylene or low molecular weight polypropylene to the toner is proposed. Have been. If a large amount of such an additive is added in order to obtain a sufficient effect, filming on the photoreceptor or contamination of the surface of the toner carrier such as a carrier or a sleeve will deteriorate the image and pose a practical problem. Therefore, a device is used in which a small amount of a release agent is added to the toner so as not to deteriorate the image, and a small amount of release oil is supplied or the offset toner is wound up with a device using a web-type member such as a web. It has been used in combination.

However, in view of recent demands for downsizing, weight reduction, and high reliability, it is necessary to remove even these auxiliary devices. It is impossible to achieve these requirements only with the copying machine itself, and therefore, it is essential to further improve the performance of the toner, such as fixing properties and anti-offset properties, including the binder resin of the toner and the release agent. It is difficult to realize without further improvements such as.

It is known that a toner contains a polyalkylene as a releasing agent.
No. 4, JP-A-52-3304, etc., a styrene-based resin may contain a monopolymer wax such as low-molecular-weight polyethylene or low-molecular-weight polypropylene.
Japanese Patent No. 3647 discloses a technique in which a styrene-based resin contains a low-molecular-weight olefin copolymer.

However, the conventional methods as the above-described means for preventing offset have drawbacks such as causing image defects such as fog due to deterioration of the charging characteristics of the toner and causing a decrease in image density. In addition, when a low molecular weight olefin copolymer is used, the adhesiveness is increased due to a decrease in crystallinity, the compatibility is improved, but the adhesiveness is increased. There were drawbacks such as deterioration.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic charge image which solves the above-mentioned problems. That is, an object of the present invention is to provide a toner for developing an electrostatic charge image which is fixed at a low temperature and has excellent offset resistance in a wide temperature range from a low temperature to a high temperature.

Another object of the present invention is to provide a toner for developing an electrostatic charge image which does not cause fusing and filming to a photosensitive member, a cleaning member or the like even in a high-speed system or for a long time. .

It is another object of the present invention to provide a toner for developing an electrostatic charge image which does not cause a long-term drop in image density due to image stains such as fog and contamination of a charging member.

Another object of the present invention is to provide a toner for developing an electrostatic charge image having excellent blocking resistance.

[0015]

SUMMARY OF THE INVENTION The present invention relates to a toner for developing an electrostatic image containing at least a binder resin and a hydrocarbon wax, and the DSC of the hydrocarbon wax measured by a differential scanning calorimeter. In the curve
Regarding the endothermic peak at the time of temperature rise and the exothermic peak at the time of temperature decrease, the onset temperature of the endothermic peak is in the range of 50 to 90 ° C., and there is at least one endothermic peak P _{1 in} the region of the temperature of 90 to 120 ° C. peak temperature ± of peak _{P 1}
Within the range of 9 ° C., there is a maximum exothermic peak at the time of temperature decrease, the wetting index of the binder resin is 37 dyn / cm (JIS wetting test method) or more, and / or the acid value is 2 mgKOH / g.
(JIS acid value) or more, and the content of the hydrocarbon wax is within 20 parts by weight based on 100 parts by weight of the binder resin.

[0016]

The toner is excellent in fixing property and excellent in anti-offset property in a wide temperature range from a low temperature to a high temperature, and is used for high-speed and long-term durable use by fusing and filming to a photoreceptor and a cleaning member. The reason why this does not occur is not always clear, but as a result of intensive studies by the present inventors, it is assumed as follows.

One of the features of the developer of the present invention is that the binder resin has a wetting index of 37 dyn / cm or more, and preferably 38 dyn / cm or more.

When the wetting index is 37 dyn / cm or more,
In particular, it has good fixability and offset resistance. According to the study of the present inventors, the wetting index of the transfer paper is 4
When the wettability of the binder resin is closer to the wettability of the transfer paper, the fixability is better. When the wetting index of the binder resin is 37 dyn / cm or more, the hydrocarbon of the present invention is used. It has been found that when both of the system waxes are used for the toner, very good fixability is exhibited.

The wetting index of a fluororesin fixing roller having good releasability is approximately 20 dyn / cm, and the more the wetting property of the binder resin is away from the wetting property of the fixing roller, the better the releasability. It has been found. In particular, it has been found that when the binder resin has a wetting index of 37 dyn / cm or more, it exhibits very good releasability when used in a toner together with the hydrocarbon wax of the present invention.

The present invention can also be achieved by using the following binder resin and the hydrocarbon wax of the present invention. One of the features is that the acid value of the binder resin is 2 mgKOH / g or more, preferably 3 mgKOH / g.
g or more. The larger the acid value, the more excellent the fixability to transfer paper and the releasability from the fixing roller and the film, but the effect starts to appear at 2 mgKOH / g or more, and becomes more effective at 3 mgKOH / g or more. However, if it exceeds 50 mgKOH / g, the developability tends to start to be affected, and if it exceeds 100 mgKOH / g, image defects such as a decrease in image density and an increase in fog start to appear. Therefore, in order to satisfy the fixing property, the anti-offset property and the developing property, the acid value is 2 mgKOH / g to 100 m
gKOH / g, preferably 3 mgKOH / g to 5
Particularly preferred is 0 mgKOH / g. Further, the wetting index of the binder resin having an acid value is 37 dyn / cm or more,
In particular, when it is 38 dyn / cm or more, the fixing property and the releasability are most excellent. This is probably because the functional group (for example, a carboxyl group) having an acid value in the binder resin has a high affinity for the cellulose of the transfer paper and has no affinity for the fluororesin of the fixing roller.

The wettability of the binder resin is determined according to JIS K-676.
8 (wetting test method). In the JIS wetting test method, a liquid with a different surface tension (a liquid with a different ratio of ethylene glycol monoethyl ether / formamide) is applied to a test piece with a cotton swab, the contraction state of the liquid film is determined, and the surface of the liquid that is completely wetted is determined. The tension (dyn / cm) is defined as “wetting scale (dyn / cm)”.

The acid value is a value measured according to JIS K-0070.

In the hydrocarbon wax of the present invention, the hydrocarbon wax has an endothermic peak at the time of temperature rise and a peak onset temperature of 50 to 90 ° C. in a DSC curve measured by a differential scanning calorimeter. In range, 90
At least one endothermic peak P in the range of
₁ is present, the maximum exothermic peak at the time of cooling is within the range of endothermic peak temperature ± 9 ° C. peak P _1, it is one of the characteristics to be satisfied.

At the time of temperature rise, a change when heat is applied to the wax can be seen, and an endothermic peak accompanying the transition and melting of the wax is observed. Peak onset temperature is 50-9
When the temperature is within the range of 0 ° C., developability, blocking resistance, and low-temperature fixability can be satisfied. If the peak onset temperature is less than 50 ° C., the change temperature of the wax is too low, resulting in a toner having poor blocking resistance or poor developability at elevated temperatures. Is too high, and sufficient fixability cannot be obtained. Within the range of 90 to 120 ° C, preferably 95 to 1
By having an endothermic peak in the range of 20 ° C, particularly preferably in the range of 97 to 115 ° C, satisfactory fixability and offset resistance can be satisfied. If the peak temperature exists only below 90 ° C., the melting temperature of the wax is too low, sufficient hot offset resistance cannot be obtained, and 120 ° C.
If the peak temperature exists only in a region exceeding the temperature, the melting temperature of the wax is too high and sufficient low-temperature offset resistance and low-temperature fixability cannot be obtained. That is, the presence of the peak temperature in this region makes it easier to balance the offset resistance and the fixability. Here, when the peak below 90 ° C. becomes the maximum peak, the same behavior as when only a peak is present in this region is exhibited. Therefore, a peak in this region may be present. It must be smaller than the peak in the region of ° C.

When the temperature is lowered, the change during cooling of the wax and the state at normal temperature can be seen, and an exothermic peak accompanying the solidification, crystallization, and transition of the wax is observed. The largest exothermic peak among the exothermic peaks at the time of cooling is the exothermic peak accompanying the coagulation and crystallization of the wax. The presence of an endothermic peak associated with melting at the time of temperature rise near the exothermic peak temperature indicates that the wax is more homogeneous, such as the structure and molecular weight distribution of the wax, and the difference is within 9 ° C. The temperature is preferably within 7 ° C., particularly preferably within 5 ° C. That is, by reducing this difference, the wax is sharp-melted, that is, hard at low temperatures, melts quickly at the time of melting, and a large decrease in melt viscosity occurs.
Developability, blocking resistance, fixability, and offset resistance can be well balanced and set. The maximum exothermic peak is a temperature of 85 to 115 ° C (preferably 90 to 110 ° C).
It is good to be in the area of.

The DSC measurement of the wax is based on the above-described toner, and the definition of each temperature is defined as follows. As a specific example, a DSC curve of wax A used in the present invention is shown in FIGS.

Endothermic peak: (Endothermic in the plus direction) Peak onset temperature: Temperature at the intersection of the tangent to the base line and the tangent of the curve at the point where the differential value of the curve at the time of temperature rise becomes the first maximum (OP .) Peak temperature: Peak top temperature (PP) Exothermic peak: (The heat is generated in the minus direction) Peak temperature: Maximum peak peak temperature The content of these hydrocarbon waxes is Resin 100
Used within 20 parts by weight to 0.5 part by weight
It is effective to use it in parts by weight, and it may be used in combination with other waxes.

The hydrocarbon wax used in the present invention is a low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure or a Ziegler catalyst under low pressure, or an alkylene polymer obtained by thermally decomposing a high molecular weight alkylene polymer. A hydrocarbon wax obtained by extracting and separating a specific component from a synthetic hydrocarbon obtained from a distillation residue of a hydrocarbon obtained from a synthesis gas consisting of carbon monoxide and hydrogen by the Ager method is used. The hydrocarbon wax is separated by a press sweating method, a solvent method, vacuum distillation, and a fractional crystallization method. That is, those obtained by removing the low molecular weight components by these methods, those obtained by extracting the low molecular weight components, and those obtained by further removing the low molecular weight components therefrom. Hydrocarbon may be added to the hydrocarbon, or an antioxidant may be added.

The hydrocarbon as a base is synthesized by a reaction between carbon monoxide and hydrogen using a metal oxide catalyst (often a multi-component system of two or more types), for example, a zincol method, a hydrochol method ( Hydrocarbons of up to several hundred carbons obtained by the fluidized catalyst bed) or by the Age method (using a fixed catalyst bed), in which a large amount of waxy hydrocarbons can be obtained (finally hydrogenated to obtain the desired product) And a hydrocarbon obtained by polymerizing an alkylene such as ethylene with a Ziegler catalyst is preferable since it is a branched, small, and saturated long-chain linear hydrocarbon. In particular, a hydrocarbon wax synthesized by a method that does not rely on the polymerization of alkylene is preferable because of its structure and a molecular weight distribution that can be easily separated. A preferred range in the molecular weight distribution is such that the number average molecular weight (Mn) is 550 to 120.
0, preferably 600-1000, and a weight average molecular weight (Mw) of 800-3600, preferably 900-3.
000, and Mw / Mn is 3 or less, preferably 2.5
Or less, particularly preferably 2.0 or less. Moreover, molecular weight 700-2400 (preferably molecular weight 750-200)
0, particularly preferably in the region of a molecular weight of 800 to 1600). By having such a molecular weight distribution, the toner can have favorable thermal characteristics. That is, if the molecular weight is smaller than the above range, the thermal effect is excessively susceptible, blocking resistance and developability are deteriorated, and if the molecular weight is larger than the above range, heat from the outside cannot be effectively used, Excellent fixability and offset resistance cannot be obtained.

As other physical properties, the density at 25 ° C. is 0.95 (g / cm ³ ) or more and the penetration is 1.5 (10 ^−1).
mm) or less, preferably 1.0 (10 ^-1 mm) or less. If the ratio is out of these ranges, it tends to change at low temperatures and tends to be inferior in storage stability and developability.

The melt viscosity at 140 ° C. is 10
It is 0 cP or less, preferably 50 cP or less, particularly preferably 20 cP or less. When the melt viscosity exceeds 100 cP, the plasticity and the releasability become poor, and excellent fixing properties and offset resistance are affected. Further, the softening point is preferably 130 ° C. or lower, particularly preferably 120 ° C. or lower. When the softening point exceeds 130 ° C., the temperature at which the mold releasability works particularly effectively becomes high, which affects the excellent offset resistance. Further, the acid value is less than 2.0 mgKOH / g, preferably 1.0 mgKOH / g.
OH / g. When the ratio exceeds this range, the interfacial adhesive strength with the binder resin, which is one of the components constituting the toner, is large, and the phase separation at the time of melting tends to be insufficient, so that good releasability is hardly obtained, The offset resistance at high temperatures is not good, and the triboelectricity of the toner is adversely affected, which may cause problems in developability and durability.

The content of these hydrocarbon waxes is not more than 20 parts by weight based on 100 parts by weight of the binder resin.
It is effective to use 0.5 to 10 parts by weight.

In the present invention, the molecular weight distribution of the hydrocarbon wax is determined by gel permeation chromatography (G
PC) under the following conditions.

(GPC measurement conditions) Apparatus: GPC-150
C (Waters) Column: GMH-HT 30 cm 2 columns (manufactured by Tosoh Corporation) Temperature: 135 ° C Solvent: o-dichlorobenzene (0.1% ionol added) Flow rate: 1.0 ml / min Sample: 0.15% 0.4 ml of the sample is injected. The measurement is carried out under the above conditions, and the molecular weight of the sample is calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample. Further, it is calculated by converting to polyethylene using a conversion formula derived from the Mark-Houwink viscosity formula.

The penetration of the wax in the present invention is J
It is a value measured according to IS K-2207. Specifically, it is a numerical value representing the penetration depth when a needle having a conical tip having a diameter of about 1 mm and a vertex angle of 9 ° is penetrated with a constant load in a unit of 0.1 mm. The test conditions in the present invention are a sample temperature of 25 ° C., a load of 100 g, and a penetration time of 5 seconds.

The melt viscosity is a value measured using a Brookfield viscometer. The conditions are a measurement temperature of 140 ° C., a shear rate of 1.32 rpm, and a sample of 10 ml.

The acid value is the number of mg of potassium hydroxide required to neutralize the acid groups contained in 1 g of the sample (JI
SK5902). Density is JIS K at 25 ° C
6760, the softening point is a value measured according to JIS K2207.

The properties required by the above wax can be achieved only by using a hydrocarbon-based wax composed of a fractionally extracted hydrocarbon, and the wax has a specific wetting index and an acid value. When combined with a binder resin, particularly excellent fixing properties can be obtained.

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

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

Particularly preferred styrene-acrylic binder resins include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, and p-styrene. Chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene,
such as p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, and p-n-dodecylstyrene Using a monomer selected from styrene and its derivatives, as acrylic monomers, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, acrylic Acrylates such as 2-ethylhexyl acrylate, stearyl acrylate, dimethylaminoethyl acrylate, phenyl acrylate and the like, and acrylic acid and acrylamide, or ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methacrylic acid Isobutyl, From methacrylates such as n-octyl acrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and methacrylic acid and methacrylamide. Styrene-acrylic copolymers using the selected monomers are preferred, and the wetting index of these styrene-acrylic copolymers is 37 dy.
In order to make n / cm or more, acrylic acid and a nitrogen-containing acrylic acid derivative, methacrylic acid and a nitrogen-containing acrylic acid derivative, and a quaternized product thereof are introduced into the copolymer from the above acrylic monomers. There is also a method using a monomer having the following acid group. In this method, the binder resin can have an acid value. Unsaturated dibasic acids and anhydride monomers such as maleic acid, citraconic acid, dimethylmaleic acid, itaconic acid, alkenylsuccinic acid and anhydrides thereof; fumaric acid, itaconic acid and dimethylfumaric acid; Further, monoesters of the above unsaturated dibasic acids. Acrylic methacrylic anhydride. Alkenyl malonic acid, alkenyl glutaric acid, alkenyl adipic acid and anhydrides and monoesters thereof.

Of these, maleic acid, fumaric acid, succinic acid, and monomers having a succinic acid structure are preferred. Particularly, maleic acid monoesters are preferred.

The binder resin used in the present invention may be a polymer cross-linked with a cross-linkable monomer as exemplified below, if necessary.

As the crosslinking agent for the binder resin, a compound having two or more polymerizable double bonds may be mainly used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; Carboxylic acid esters having two double bonds such as glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butadiol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and 3
Compounds having at least two vinyl groups are used alone or as a mixture.

In the developer of the present invention, it is preferable to use a charge control agent mixed (internally added) to the developer particles or mixed (externally added) with the developer particles. The charge control agent makes it possible to control the amount of charge optimally according to the development system. In particular, in the present invention, the balance between the particle size distribution and the charge can be further stabilized. Examples of the positive charge controlling agent include denatured products such as nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonic acid and tetrabutylammonium tetrafluoroborate, and analogs thereof. Onium salts such as phosphonium salts and the like, lake pigments thereof, triphenylmethane dyes and these lake pigments, (phosphorus tungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic Acid, ferricyanide, ferrocyanide, etc.) Metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borane DOO, diorgano tin borate such as dicyclohexyl tin borate; can be used in combination singly or two or more kinds. Among these, charge control agents such as nigrosine, quaternary ammonium salts, and triphenylmethane pigments are particularly preferably used.

In addition, the general formula

[0048]

Embedded image Monomer of a monomer represented by: styrene described above,
Copolymers with polymerizable monomers such as acrylates and methacrylates can be used as positive charge control agents. In this case, these charge control agents also act as (all or part of) the binder resin.

The following substances control the toner to be negatively charged.

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

The above-described charge control agent (having no action as a binder resin) is preferably used in the form of fine particles. In this case, the number average particle size of the charge control agent is
Specifically, it is preferably 4 μm or less (more preferably 3 μm or less).

When internally added to the developer, such a charge control agent is preferably used in an amount of 0.1 to 20 parts by weight (more preferably 0.2 to 10 parts by weight) based on 100 parts by weight of the binder resin. .

The silica fine powder used in the present invention is BE
The specific surface area by nitrogen adsorption measured by the T method is 30 m ² / g
Those within the above range (particularly 50 to 400 m ² / g) give good results. It is preferable to use 0.01 to 8 parts by weight, preferably 0.1 to 5 parts by weight of silica fine powder with respect to 100 parts by weight of the toner.

The silica fine powder used in the present invention is:
Silicon varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having a functional group, other organosilicon compounds, etc., for the purpose of hydrophobicity, charge control, etc., if necessary It is also preferable that the composition is treated in combination with the above-mentioned treating agent or with various treating agents.

As other additives, for example, lubricant powders such as Teflon powder, zinc stearate powder, and polyvinylidene fluoride powder are preferable, and polyvinylidene fluoride is particularly preferable.
Alternatively, abrasives such as cerium oxide powder, silicon carbide powder, and strontium titanate powder, among which strontium titanate is preferred. Or, for example, titanium oxide powder,
Fluidity-imparting agents such as aluminum oxide powder, particularly hydrophobic ones are preferred. A small amount of a caking preventing agent, or a conductivity-imparting agent such as a carbon black powder, a zinc oxide powder, an antimony oxide powder, or a tin oxide powder, or white and black fine particles of opposite polarity can also be used as a developer improver.

Further, when the toner of the present invention is used as a two-component developer, it is used by mixing with a carrier powder. In this case, the mixing ratio of the toner and the carrier powder is 0.1 to 50% by weight as the toner concentration, preferably 0.5%.
It is preferably from 10 to 10% by weight, more preferably from 3 to 10% by weight.

As the carrier usable in the present invention, known carriers can be used. For example, magnetic powders such as iron powder, ferrite powder and nickel powder, glass beads, etc. And those treated with a vinyl resin or a silicone resin.

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

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

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

The colorant that can be used in the toner of the present invention includes any suitable pigment or dye. As a colorant of the toner, for example, carbon black as a pigment,
Examples include aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, red bengala, phthalocyanine blue, and induslen blue. These are used in an amount necessary and sufficient to maintain the optical density of the fixed image, and are preferably added in an amount of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight based on 100 parts by weight of the resin. A dye is further used for the same purpose. For example, azo dyes, anthraquinone dyes,
There are xanthene dyes, methine dyes and the like.
0.1 to 20 parts by weight, preferably 0.3 to parts by weight
The addition amount of 10 to 10 parts by weight is good.

To prepare the toner for developing an electrostatic image according to the present invention, a binder resin, a wax, a metal salt or a metal complex, a pigment or dye as a colorant, a magnetic substance, a charge control agent if necessary, While the other additives, etc. were thoroughly mixed by a mixer such as a Henschel mixer, a ball mill, and then melt-kneaded using a heat kneader such as a heating roll, a kneader, or an extruder to make the resins compatible with each other. The toner according to the present invention can be obtained by dispersing or dissolving a metal compound, a pigment, a dye, and a magnetic substance, and performing cooling and solidification followed by pulverization and classification.

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

[0064]

The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

First, the hydrocarbon wax used in the present invention will be described.

Wax A (the present invention) and wax B (the present invention) from hydrocarbon wax synthesized by the Age method
And wax C (invention) were obtained by fractional crystallization.

Using a Ziegler catalyst, ethylene was subjected to low pressure polymerization to obtain wax E (comparative example) having a relatively low molecular weight.
Wax D (the present invention) from which low molecular weight components had been removed to some extent by fractional crystallization was obtained. These physical properties are shown in Tables 1 and 2.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

[Table 3] Next, a synthesis example of the binder resin used in the toner of the present invention will be described. Tables 4 and 5 show the wetting index and the acid value of the binder resin used in this example.

Synthesis Examples 2 and 3 were synthesized in the same manner as in Synthesis Example 1 using the starting materials shown in Table 4.

Synthesis Example 1 Styrene 70.00 parts by weight n-butyl acrylate 15.00 parts by weight Acrylic acid 15.00 parts by weight Di-tert-butyl peroxide 1.50 parts by weight The above compound was heated to 200 parts by weight of toluene. The solution was dropped over 4 hours. Further, the polymerization was completed under reflux of toluene, and toluene was removed while raising the temperature (120 ° C.) under reduced pressure.

The above resin 30.00 parts by weight Styrene 44.65 parts by weight n-butyl acrylate 20.00 parts by weight Mono-n-butylmale 5.00 parts by weight Divinylbenzene 0.35 parts by weight Benzoyl peroxide 1.20 parts by weight Di-tert-butylperoxy-2-0.70 parts by weight Ethyl hexanote
170 parts by weight of water in which 2 parts by weight were dissolved were added, and the mixture was vigorously stirred to obtain a suspension dispersion. The above-mentioned suspension dispersion was added to a reactor in which 50 parts by weight of water had been added and purged with nitrogen.
The suspension polymerization reaction was carried out for an hour. After the reaction, wash with water, dehydrate,
After drying, resin A was obtained.

[0074]

[Table 4] Synthesis Example 4 78.90 parts by weight of styrene 20.00 parts by weight of n-butyl acrylate 1.00 part by weight of mono-n-butylmalate 0.10 part by weight of divinylbenzene 0.20 part by weight of 2,2-azobis- (2,4 -Dimethylvaleronitrile) From the above compound, a polymer A was obtained by a solution polymerization method using xylene as a solvent.

75.00 parts by weight of styrene 14.00 parts by weight of n-butyl acrylate 1.00 parts by weight of mono-n-butylmalate 1.00 parts by weight of di-t-butyl peroxide From the above compounds, polymer A and polymer B was mixed with the solution at a weight ratio of 40:60 to obtain a binder resin 4.

Synthesis Examples 5 to 7 were synthesized in the same manner as in Synthesis Example 4 using the starting materials shown in Table 5.

[0077]

[Table 5] Example 1 Binder resin A 100 parts by weight Iron tetroxide 90 parts by weight Metal complex of monoazo dye 2 parts by weight Wax A 4 parts by weight After the above materials were mixed well by a blender, a twin-screw kneading extruder set at 150 ° C. Was melt-kneaded. The obtained kneaded material was cooled, coarsely pulverized by a cutter mill, and then finely pulverized using a fine pulverizer using a jet stream, and the obtained finely pulverized powder was classified by a fixed wall type air classifier. A classified powder was produced. In addition, the obtained classified powder is multi-divided using the Coanda effect (Nippon Mining Co., Ltd. elbow jet classifier)
Then, the ultrafine powder and the coarse powder were strictly classified and removed at the same time to obtain a toner A having a volume average diameter of 9.0 μm.

Further, 100 parts by weight of toner A 0.8 parts by weight of hydrophobic silica fine particles 3.0 parts by weight of strontium titanate fine particles The above materials were mixed with a Henschel mixer to obtain a developer A.

This developer was used in a commercially available electrophotographic copying machine NP-
Using 6550 (manufactured by Canon Inc.), fixability and offset resistance were evaluated. Fixing property is low temperature environment (7.5
At 200 ° C.) and leave the evaluator and the fixing unit inside the evaluator and the fixing unit inside the copier in a state of being sufficiently adapted to a low-temperature environment. Used for evaluation. For the evaluation of the fixing property, the image was rubbed with a silbon paper 10 times in a reciprocating manner at a load of about 100 g, and the peeling of the image was evaluated by the reduction rate (%) of the reflection density. The offset property was examined by examining whether image contamination occurred during continuous copying of 200 sheets of copied images.

As a result, the fixability was good and no offset occurred. Also stop the cleaning web,
An intermittent copying test was performed to check the cleaning properties of the fixing roller. There is no image stain even at 10,000 sheets,
The fixing roller was not damaged. Also, 500c
100 g of the developer was placed in the c-polycup and left in an environment of 50 ° C. for one week to perform a blocking test. Table 6 shows the evaluation results.

Example 2 100 parts by weight of binder resin C 90 parts by weight of iron sesquioxide 90 parts by weight Metal complex of monoazo dye 2 parts by weight 4 parts by weight of wax B The above material was produced in the same manner as in Example 1 to prepare toner B. Obtained.

Further, 100 parts by weight of toner B 0.8 parts by weight of hydrophobic silica fine particles 3.0 parts by weight of strontium titanate The above materials were mixed with a Henschel mixer to obtain a developer B. Evaluation was performed in the same manner as in Example 1. Table 6 shows the results
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Comparative Example 1 100 parts by weight of binder resin B 90 parts by weight of iron tetroxide 2 parts by weight of metal salt of dialkylsalicylic acid 4 parts by weight of wax A The above materials were produced in the same manner as in Example 1, and toner C was prepared. Obtained.

Further, 100 parts by weight of toner C 0.8 parts by weight of hydrophobic silica fine particles 3.0 parts by weight of strontium titanate The above materials were mixed with a Henschel mixer to obtain a developer C. Evaluation was performed in the same manner as in Example 1. Table 6 shows the results
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Example 3 100 parts by weight of binder resin D 80 parts by weight of triiron tetroxide 3 parts by weight of nigrosine 4 parts by weight of wax C The above material was produced in the same manner as in Example 1 to obtain toner D.

Further, 100 parts by weight of toner D 0.6 parts by weight of fine particles of positively charged hydrophobic silica 0.2 parts by weight of fine particles of polyvinylidene fluoride The above materials were mixed with a Henschel mixer to obtain a developer D.

This developer was used in a commercially available electrophotographic copying machine NP-
Using 3825 (manufactured by Canon Inc.), fixability and offset resistance were evaluated. Fixability is low temperature environment (7.5 ℃)
Leave the evaluator overnight at, take a copy image from the state where the evaluator and the fixing device inside it are well adapted to low temperature environment,
The first copy image was used for evaluation of fixability. The evaluation of the fixability is as follows.
Rubbing with load, image peeling, decrease in reflection density (%)
Was evaluated. The offset property is 200 sheets of B5 transfer paper continuously.
After taking one copy image, the copy paper of A3 was taken, and it was examined whether image contamination occurred.

As a result, the fixability was good and no offset occurred. Also stop the cleaning web,
An intermittent copying test was performed to check the cleaning properties of the fixing roller. There is no image stain even at 10,000 sheets,
The fixing roller was not damaged. Also, 500c
100 g of the developer was placed in the c-polycup and left in an environment of 50 ° C. for one week to perform a blocking test. Table 6 shows the evaluation results.

Comparative Example 2 Binder resin D 100 parts by weight Iron tetroxide 80 parts by weight Nigrosine 2 parts by weight Wax E 4 parts by weight The above materials were produced in the same manner as in Example 1 to obtain toner E.

Further, 100 parts by weight of toner E 0.6 parts by weight of positively charged hydrophobic silica fine particles 0.2 part by weight of polyvinylidene fluoride fine particles 0.2 part by weight The above materials were mixed with a Henschel mixer to obtain a developer E. Evaluation was performed in the same manner as in Example 3. Table 6 shows the results
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Comparative Example 3 Binder resin E 100 parts by weight Iron trioxide 80 parts by weight Nigrosine 2 parts by weight The above material was produced in the same manner as in Example 1 to obtain toner F.

Further, 100 parts by weight of toner F 0.6 parts by weight of positively charged hydrophobic silica fine particles 0.2 part by weight of polyvinylidene fluoride fine particles 0.2 part by weight The above materials were mixed with a Henschel mixer to obtain a developer F. Evaluation was performed in the same manner as in Example 3. Table 6 shows the results
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Example 4 100 parts by weight of binder resin F 80 parts by weight of triiron tetroxide 2 parts by weight of triphenylmethane lake pigment 4 parts by weight of wax D The above material was produced in the same manner as in Example 1 to prepare toner G. Obtained.

Further, 100 parts by weight of toner G 0.6 parts by weight of positively-charged hydrophobic silica fine particles The above materials were mixed with a Henschel mixer to obtain a developer G. Evaluation was performed in the same manner as in Example 3. Table 6 shows the results
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Comparative Example 4 100 parts by weight of binder resin F 80 parts by weight of triiron tetroxide 2 parts by weight of triphenylmethane lake pigment The above materials were produced in the same manner as in Example 1 to obtain toner H.

Further, 100 parts by weight of toner H 0.6 parts by weight of positively charged hydrophobic silica fine particles The above materials were mixed with a Henschel mixer to obtain a developer H. Evaluation was performed in the same manner as in Example 3. Table 6 shows the results
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Example 5 Binder resin G 100 parts by weight Iron trioxide 80 parts by weight Quaternary ammonium salt 1 part by weight Wax A 4 parts by weight Was.

Further, 100 parts by weight of toner I 0.6 parts by weight of positively charged hydrophobic silica fine particles The above materials were mixed with a Henschel mixer to obtain developer I. Evaluation was performed in the same manner as in Example 3. Table 6 shows the results
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Example 6 100 parts by weight of binder resin H 80 parts by weight of triiron tetroxide 4 parts by weight of wax A The above materials were produced in the same manner as in Example 1 to obtain toner J.

Further, 100 parts by weight of toner J 1.0 part by weight of positively-chargeable hydrophobic silica fine particles The above materials were mixed with a Henschel mixer to obtain a developer J. Evaluation was performed in the same manner as in Example 3. Table 6 shows the results
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[0101]

[Table 6]

[0102]

According to the toner of the present invention having the above-described characteristics, it has excellent fixing properties, anti-offset properties and anti-blocking properties, is strong in fusing, and gives a clear image even in long-term durable image formation.

[Brief description of the drawings]

FIG. 1 shows the DS of the wax A according to the present invention when the temperature is raised.
It is a figure showing a C curve.

FIG. 2 shows the DS of the wax A according to the present invention when the temperature is lowered.
It is a figure showing a C curve.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masashi Jimbo 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tsutomu Onuma 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside the Company (72) Inventor Masayoshi Uchiyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 9/08

Claims (2)

(57) [Claims] At least a binder resin and a hydrocarbon-based washer.
Toner for developing electrostatic images containing particles,  Measured by differential scanning calorimeterThe hydrocarbon wax
OfIn the DSC curve, the endothermic peak at the time of temperature rise and the temperature fall
The endothermic peak onset temperature
In the range of 50-90 ° C, temperature range of 90-120 ° C
At least one endothermic peak P₁The endothermic
Ark P₁Maximum temperature when temperature falls within the range of peak temperature of ± 9 ° C
Heat peakYes,  Wetting index of the binder resinIs37dyn / cm (JIS
Test method)And / or an acid value of 2 mg KO
H / g (JIS acid value) or more, When the content of the hydrocarbon-based wax is 100
Not more than 20 parts by weight based on parts by weight Characterized by static
Charge image developing toner. 2. The method according to claim 1 , wherein the content of said hydrocarbon wax is binding.
0.5 to 10 parts by weight based on 100 parts by weight of resin
The toner for developing an electrostatic image according to claim 1, wherein
-