JPH0675433A - Toner and image forming method - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a toner that does not cause toner fusion on a photoconductor, is less likely to contaminate a contact charging device with toner, and can obtain an image with high density and no fog. . A toner for use in an image forming method, comprising a contact charging unit that contacts the surface of a latent image carrier and / or a rotating body for transfer that contacts the surface of the latent image carrier, the toner being a triphenylmethane-based toner. Resin particles containing at least a compound and a binder resin and inorganic oxide fine powder are contained, and the THF-soluble component of the toner has a molecular weight distribution of 3,000 to 5 in terms of molecular weight distribution by GPC (gel permeation chromatography). There is at least one peak in the region of 100,000 and at least one peak in the region of molecular weight of 100,000 or more, and 50 to 90% of the components having the molecular weight of 100,000 or less
The toner is characterized in that

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner and an image forming method for developing an electrostatic latent image in an image forming method such as electrophotography and electrostatic recording.

[0002]

2. Description of the Related Art FIG. 1 shows a schematic structure of general electrophotography. In the figure, reference numeral 1 denotes a drum type photoconductor, which is driven to rotate in the arrow direction. The photoconductor 1 is uniformly charged by the charging device 2, and then imagewise exposed by the exposure unit 3. As a result, electrostatic latent images are sequentially formed on the photoconductor.

The electrostatic latent image is then developed by the toner of the developing device 4. This developed image is transferred by the transfer device 5.
The images are sequentially transferred onto a transfer material P such as paper fed between the photoconductor and the transfer device 5.

The transfer material P which has received the image transfer is separated from the surface of the photoconductor and is introduced into the fixing device 8 to form a copy.

Toner remaining on the photoconductor is removed by the cleaning device 6, and the photoconductor after cleaning is neutralized by the static elimination exposure 7.

As shown in the figure, as the charging device 2 and the transfer device 5, a corotron, a scorotron or the like has been generally used conventionally. This is a method in which a high voltage is applied to a thin wire such as tungsten, and ions are emitted from the wire.

However, in such a device, a large amount of ozone is generated and its odor is disliked.

Further, such a device has a problem that most of the ions emitted from the wire 2a flow into the casing 2b and the efficiency is poor. On the contrary, if there is no casing, it is necessary to supply an extremely high voltage for discharging.

In order to solve these problems, if the distance between the thin wire and the member to be charged is reduced, the uneven charging may occur due to fine irregularities on the surface of the member to be charged, or spark discharge may occur.

Further, in such a system, there is a problem of reliability that the wire is deteriorated and cut during use, and a problem that the wire is contaminated with fine particles of an inorganic oxide and leads to an image defect.

In order to solve such a problem, a method of applying a voltage to a conductive material that is in direct contact with the photoconductor has been adopted as a charging system, and a conductive roller is similarly applied to the photoconductor as a transfer system. The structure which makes direct contact has been adopted.

[0012] These methods can solve the above-mentioned problems such that the generation of ozone can be extremely reduced, and further, high voltage is not required, so that downsizing and cost reduction can be achieved.

However, since the member is in direct contact with the photosensitive member, an adverse effect occurs. That is, the transfer residual toner that has not been transferred onto the transfer material is cleaned by the cleaning device 6, but at this time, the photoconductor is not always completely cleaned, and a small amount of toner or components in the toner remains. It is inevitable to do.
Then, the substance on the photoconductor is subjected to the force of being crushed by the member which is in direct contact with the photoconductor for charging or transfer. For this reason, a phenomenon in which toner or the like is fused to the photoconductor is likely to occur.

Furthermore, the fact that a voltage is applied to the member promotes this phenomenon. In recent years, not only small-sized copying machines, but also high-speed, large-sized copying machines have begun to employ contact charging and a rotating body for transfer. At this time, it is necessary to increase the applied voltage and the AC frequency as the copying speed increases in order to stabilize charging and transfer. However, this promotes toner fusion to the photoreceptor. Further, a high-speed / large-sized copying machine needs to extend the number of durable photosensitive members, which also makes the problem more serious.

To solve such a problem, Japanese Patent Laid-Open No. 3-85
In 572, it is proposed that the surface of the transfer roller is a ground surface, and in Japanese Patent Laid-Open No. 3-102382, it is proposed to increase the charge amount of the toner by an auxiliary charging means to prevent the dirt of the drum. ing. However, such an improvement in the apparatus sacrifices other functions or increases the cost, and therefore, a method for solving the problem without improving the apparatus has been desired.

[0016]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner and an image forming method which do not cause toner fusion on the photosensitive member.

Another object of the present invention is to provide a toner and an image forming method capable of obtaining an image having a high density without fog and having no voids during transfer.

Another object of the present invention is to provide a toner and an image forming method in which the contact charging device is unlikely to be contaminated with toner, and even if it is contaminated, uneven charging does not occur.

Another object of the present invention is to provide a toner and an image forming method which are less likely to contaminate the transfer rotary member with the toner, and do not cause transfer failure even if the contamination occurs.

That is, the object of the present invention is to
It is an object of the present invention to provide a novel toner and an image forming method that solve the above problems.

[0021]

[Means and Actions for Solving the Problems]
This is achieved by the following configuration.

That is, a toner containing at least a compound represented by the following general formula (I) or a compound obtained by laking the compound, a resin particle containing at least a binder resin, and an inorganic oxide fine powder, The toner is a toner used in an image forming method that includes a contact charging unit that contacts the surface of the latent image carrier and / or a transfer rotator that contacts the surface of the latent image carrier. In the molecular weight distribution by GPC (gel permeation chromatography), at least one peak exists in the region of molecular weight 3,000 to 50,000, at least one peak exists in the region of molecular weight 100,000 or more, and molecular weight of 100,000 or less. Achieved by toners, where the components are 50-90%.

[0023]

[Chemical 3] [Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are the same or different from each other, a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl Represents a group. R ⁷ , R ⁸ and R ⁹ are each a hydrogen atom, a halogen atom, which may be the same or different,
It represents an alkyl group or an alkoxy group. A ^- is an anion such as sulfate ion, nitrate ion, borate ion, phosphate ion, hydroxide ion, organic sulfate ion, organic sulfonate ion, organic phosphate ion, carboxylate ion, organic borate ion, and tetrafluoroborate. Indicates. Furthermore, this toner is used in an image forming method equipped with a contact charging unit that contacts the surface of the latent image carrier and / or a rotating body for transfer that contacts the surface of the latent image carrier. This is accomplished by developing the held electrostatic latent image.

The present invention will be described in detail below.

The inventors of the present invention prevent fusion of toner by using a compound represented by the above formula (I) or a compound obtained by laking this in a structure in which there is a member in contact with the photoconductor. It has been found that the present invention is extremely effective against, and has reached the present invention.

One of the reasons seems to be that the charge amount of the toner can be increased to an appropriate level for transfer. Since transfer is basically a process using an electric field, the electrostatic charge can be more strongly exerted when the toner charge amount is higher. Therefore, a toner having a high charging ability is more efficiently transferred, the residual toner on the photoconductor is reduced, and it is preferable for toner fusion. Especially when an abrasive additive is added to the toner to prevent toner fusion,
Although the amount of charge tends to decrease and the image density tends to decrease, it is preferable that the toner has a high chargeability also from this point of view.

The compound represented by the general formula (I) is one of triphenylmethane dyes and pigments. The use of such a triphenylmethane compound in the technical field is disclosed in JP-B-57-3940 and JP-A-54-84732.
JP-B-58-9415, JP-A-55-7
No. 9456, No. 60-107654, No. 61-124955, No. 61-3675.
No. 8, JP-A-2-73260, and JP-A 2-1.
It is known in Japanese Patent No. 23372, Japanese Unexamined Patent Publication No. 2-273754 and the like.

The positive triboelectrification property of the triphenylmethane compound is greatly affected by the amino group substituting the phenyl group. As a result of examining various compounds, Japanese Patent Publication No. 57-
Only two phenyl groups as disclosed in 3940, JP-A-54-84732, JP-B-58-9415 and JP-A-60-107654 are substituted with amino groups. The triphenylmethane derivative was insufficient in the triboelectrification imparting ability in the image forming method of the present invention. That is, as described above, in order to prevent toner fusion on the photoreceptor, it is preferable to increase the triboelectric charge amount of the toner, but a triphenylmethane derivative in which only two phenyl groups are substituted with amino groups However, the triboelectric charge amount was insufficient to prevent toner fusion.

On the other hand, one in which one of the three phenyl groups is changed to a naphthyl group is disclosed in JP-A-55-79456,
JP-A-61-2124955 and JP-A-61-367
No. 58, etc., the positive triboelectric charge amounts of these compounds were too high in the image forming method of the present invention. That is, if the amount of charge of the developed toner becomes excessive, the adhesion of the toner to the photoconductor based on the mirroring force becomes strong, and it is generally difficult to remove the toner by the cleaning device. Therefore, when a toner containing these compounds is applied to the image forming apparatus of the present invention, toner fusion easily occurs.

As described above, it was newly found that the triphenylmethane dyes and pigments that can be effectively used in the image forming apparatus of the present invention are limited to those conventionally known.

Further, in order to completely prevent the fusion of the toner, it is not enough to use the compound represented by the above formula (I), and the design of the binder resin as described later is also an essential requirement. In the case of the binder resin of the present invention, the dispersive power in the kneading step of toner production tends to be weaker than that of a normal resin. Therefore, the additive of the present invention is required to have a property that it can be well dispersed in the binder resin even with a weak dispersing force. As a result of investigations by the present inventors, it was found that the compound represented by the above formula (I) has good dispersibility in a resin even with a weak dispersive force as compared with other known charge imparting agents.

That is, the compound represented by the above formula (I) is a triphenylmethane dye / pigment having the most suitable triboelectrification property in the image forming method of the present invention, and has good dispersibility in the resin of the present invention. I found that. The characteristic of having good dispersibility, high triboelectric chargeability, and not exhibiting excessive triboelectricity makes the triboelectric charge amount distribution of the toner sharp, and thus greatly contributes to image stabilization.

Specific examples of the compound represented by the above formula (I) are shown below, but the invention is not limited thereto.

[0034]

[Chemical 4]

[0035]

[Chemical 5] The compound is laked by a known method. For example, an aqueous solution of a laker is added to an aqueous solution of a compound of acetic acid to precipitate a lake pigment. Alternatively, an extender pigment is suspended in an aqueous acetic acid solution of a compound, and then an aqueous solution of a laker is added to deposit the lake pigment on the surface of the extender pigment. As the lake agent, phosphotungsten molybdic acid, phosphotungstic acid, a water-soluble salt of phosphomolybdic acid, and
There are water-soluble salts containing complex anions such as ferrocyan and ferricyan. Organic acid salts can also be used as a laking agent, but gallic acid lakes, for example, do not have very good charging characteristics. This is the organic acid lake,
This is probably because the compatibility of the resin and the rake is good, so that the properties of the resin having a poor charging property appear remarkably.

As a method of incorporating the above-mentioned pigment, that is, the charge control agent used in the present invention into the toner, there are a method of adding it inside the toner and a method of adding it externally. The amount of these charge control agents used is determined according to the type of binder resin, the presence or absence of other additives, and the toner manufacturing method including the dispersion method, and is not uniquely limited. It is preferably used in an amount of 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the binder resin. When externally added, the amount is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the resin, and particularly preferably mechanochemically fixed to the surface of the toner particles.

The charge control agent used in the present invention can also be used in combination with a conventionally known charge control agent.

Inorganic oxide fine powder is added to the toner having the charge control agent of the present invention. Silica or alumina treated with a silane coupling agent and / or a silicone oil having a side chain containing a nitrogen atom. Alternatively, it is preferable to externally add a fine powder of titania.

The inventors of the present invention have found that the use of the fine powder as described above is very effective in preventing toner fusion in a structure in which there is a member that contacts the photoconductor. I found it.

The reason for this seems to be as follows. It is generally known that when the toner fusion occurs, the inorganic oxide fine powder is likely to be attached to the photoconductor. The mechanism seems to be as follows. If the inorganic oxide fine powder is separated from the toner surface, the inorganic oxide fine powder is so fine that it easily slips through the cleaning device. The fine inorganic oxide powder that has slipped off covers the photoconductor thinly. It is considered that that part of the photoconductor changes in properties such as abrasion resistance and affinity of the toner with the resin to induce toner fusion.

On the other hand, among the above-mentioned fine powders, those treated with the silane coupling agent are easily disentangled when added to the toner, and the fine powders aggregated, so-called "damage" is reduced. Therefore, since the amount of fine powder released from the toner surface is small, toner fusion is not induced unlike the above mechanism. However, if the type of silane coupling agent is selected and not carefully treated, the chargeability and hydrophobicity may be unsatisfactory.

Among the above fine powders, those treated with a silicone oil having a side chain containing a nitrogen atom,
It has the effect of preventing toner fusion. Although the detailed mechanism is unknown, it is considered that the external transfer of fine powder treated with silicone oil having a side chain containing a nitrogen atom improves the transferability of the toner. The transferability of the toner is improved by the effect of nitrogen atoms, which gives a stable positive charging property and behaves faithfully to the transfer electric field, and by the viscosity of the silicone oil,
It seems that the adhesion between the toner particles is suitable for transfer. When the transferability of the toner is good, the amount of the toner remaining on the photoconductor is reduced, so that the toner fusion is suppressed. However, care must be taken when treating with silicone oil, as it can easily cause lumps.

Fine powder treated with both a silane coupling agent and a silicone oil having a nitrogen atom-containing side chain is most preferable for preventing toner fusion. Since it is treated with both, the amount of fine powder is less than that treated with only silicone oil. Therefore, the amount of fine powder released from the toner surface is reduced, and toner fusion is prevented. Further, since it is treated with a silicone oil having a side chain containing a nitrogen atom, stable positive chargeability and the effect of preventing toner fusion due to the viscosity of the silicone oil can be obtained.

In addition to anhydrous silicon dioxide (silica), silicates such as aluminum silicate, sodium silicate, potassium silicate, magnesium silicate and zinc silicate can be used as the base fine silica powder to be treated. Applicable. In addition, either a dry method or a wet method can be used.

Further, as the silica fine powder to be added, it is preferable to use positively chargeable silica fine powder rather than being negatively chargeable.

In the present invention, treatment with a silicone oil having an organo group having at least one nitrogen atom in its side chain is used in order to obtain finely charged silica powder.

As the silicone oil having a nitrogen atom in the side chain, one having a structure represented by the formula (II) can be generally used.

[0048]

[Chemical 6] (Wherein R ₁ and R ₆ represent hydrogen, an alkyl group, an aryl group or an alkoxy group, R ₂ represents an alkylene group or a phenylene group, and R ₃ represents a compound having a nitrogen-containing heterocycle in its structure, R ₄ and R ₅ are hydrogen, an alkyl group,
Represents an aryl group. Further, R ₂ may be omitted. However, the above-mentioned alkyl group, aryl group, alkylene group and phenylene group may contain an amine, and may have a substituent such as halogen within a range not impairing the charging property. Also, j is a number of 1 or more, and k, m, and n are positive numbers including 0. k + m + n is a positive number of 1 or more. The most preferred structure among the above structures is one having 1 or 2 nitrogen atoms in the side chain containing the nitrogen atom. Many heterocycles containing nitrogen have been known so far, and examples thereof are given below.

[0049]

[Chemical 7] An example of a saturated heterocycle containing nitrogen is given below.

[0050]

[Chemical 8] As the silane coupling agent used in the present invention, conventionally known ones can be used.

For example, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane,
Benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane, etc. Ethoxysilane, dimethylaminopropyltrimethoxysilane, diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane,
Dibutylaminopropyltrimethoxysilane, monobutylaminopropyltrimethoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropyldimethoxysilane, dibutylaminopropylmonomethoxysilane, dimethylaminophenyltriethoxysilane, trimethoxysilyl-γ-propylphenyl Use of amines, trimethoxysilyl-γ-propylbenzylamine and the like, and those containing the above-mentioned structures as nitrogen-containing heterocycles such as trimethoxysilyl-γ-propylpiperidine and trimethoxysilyl-γ-propylimidazole. You can

As the treating agent in the present invention, it is preferable to use two kinds of silicone oil (A) having a nitrogen atom in the side chain and nitrogen-containing silane coupling agent (B). These two types may be mixed in advance and treated at the same time, or may be treated with the treatment agent (B) and then the treatment agent (A) in this order. ,
It is not preferable to treat the treatment agent (B).

This is probably because the fine silica powder agglomerates when treated with silicone oil first, and the treated silica particles are less likely to become fine. Since fine silica particles and less "damage" lead to the effect of the present invention, the nitrogen-containing silane coupling agent and the silicone oil having a nitrogen atom in the side chain are simultaneously treated before the final heat treatment. It is preferable that the fine silica particles are uniformly present on the surface.

Fine particles of titania and alumina are also preferable as the fine particles of inorganic oxide used in the present invention.

Generally, when surface treatment is performed on silica fine powder, it is necessary to use a treatment agent such as amino-modified silicone oil in order to achieve both hydrophobicity and positive chargeability.
However, the oil-based treatment agent is difficult to perform uniform treatment,
"Dama" is formed and it is difficult to loosen fine particles. On the other hand, fine powders of titania and alumina are
It does not have a strong negative charge like silica fine powder. For this reason,
Both hydrophobicity and chargeability can be achieved without using an oil-based treatment agent. Therefore, the fine powder of titania and alumina as the fine inorganic oxide powder is easily loosened into fine particles and less "damage" is obtained. By using such titania fine powder in the present invention, toner fusion is prevented. Among the above inorganic oxide fine powders, BET
Preferably the base fine powder within the scope of the specific surface area by the measured nitrogen adsorption is 40 m ² / g or more (especially 50 to 400 m ² / g) by law, the treated fine powder, 3
Within the scope of 0 m ² / g or more (especially 70~350m ² / g) it is preferable.

The applied amount of these fine inorganic oxide powders exerts an effect when the amount is 0.01 to 20% with respect to the weight of the developer, and is particularly preferable when 0.03 to 5% is added. It shows fluidity and stable chargeability. The preferred mode of addition is 0.01 to 0.01% by weight of the developer.
It is preferable that 3% by weight of the inorganic oxide fine powder is attached to the surface of the toner particles.

Finally, when the degree of hydrophobicity of the inorganic oxide fine powder is hydrophobized to show a value of 30 or more as the degree of hydrophobicity measured by the methanol titration test, the triboelectric charge amount of the toner is It is preferable because it shows a sharp and uniform positive charging property.

The "methanol titration test" defined in this specification for evaluating the degree of hydrophobicity of fine inorganic oxide powders is carried out as follows. 0.2 g of the fine inorganic oxide powder to be tested is added to 50 ml of water in an Erlenmeyer flask having a volume of 250 ml. Methanol is titrated from the burette until the total amount of fine inorganic oxide powder is wet. At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed by suspending the total amount of fine inorganic oxide powder in the liquid, and the degree of hydrophobization is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

As the binder resin used in the present invention, the molecular weight distribution of the toner is a molecular weight distribution by GPC of the THF soluble component, and at least one peak exists in the region of the molecular weight of 3,000 to 50,000. At least 1 in more than 100,000 areas
There are two peaks, and components with a molecular weight of 100,000 or less are 50 to 9
A binder resin that gives 0% is used.

The inventors of the present invention are very effective in preventing toner fusion when the binder resin as described above is used in a structure in which there is a member in contact with the photoconductor. I found it.

The reason for this seems to be as follows. In the toner fusion, the toner is deformed due to the stress caused by heat and pressure. Therefore, if the toner is hard to be deformed by heat and pressure, the toner fusion should be unlikely to occur. However, such toner generally deteriorates the fixing property. To achieve this balance,
It is necessary to consider the temperature dependence of viscoelasticity. That is,
In the environment where toner fusion occurs, heat is mainly due to friction. Therefore, the temperature becomes lower than that at the time of fixing. Therefore, when the temperature is relatively low, the elasticity is high and it is difficult to be deformed by the pressure, but when the temperature is high as in fixing, the elasticity is preferably low. When the binder resin has the above-mentioned molecular weight distribution, the temperature dependence of viscoelasticity becomes preferable.

The elastic property is controlled by a relatively high molecular weight component, but in the present invention, it is necessary that at least one peak exists in a region having a molecular weight of 100,000 or more, preferably 300,000 to 5,000,000. There should be at least one peak in the region. More preferably, 300,000-2
In the area of, 000,000, it is preferable that the maximum peak is in the area of 100,000 or more. Furthermore, this peak is 2
The second largest peak is the most preferable form for balancing toner fusion and fixing. When the peak of the high molecular weight component is in the region of more than 5 million, the elasticity is too high and good fixing property cannot be obtained. If the peak does not exist in the area of 100,000 or more, the elasticity is too low and the offset is likely to occur during fixing.

In the present invention, at least one peak must exist in the molecular weight range of 3,000 to 50,000, preferably in the range of 3,000 to 30,000, and more preferably in the range of 5,000 to 20,000. At least one peak should be present. Furthermore, the maximum peak in this region is the most preferable form in order to obtain good fixability and good dispersibility of the pigment added as the charge control agent. If there is no peak in the region of 50,000 or less, the viscosity is insufficient and good fixability cannot be obtained. Further, even in the region of 50,000 or less, when the peak of the low molecular weight component is in the region of less than 3,000, a good pigment dispersion state cannot be obtained.

Further, the present invention is characterized in that the weight fraction of the polymer having a molecular weight of 100,000 or less is 50 to 90%.
% Is particularly preferable. By being in this range,
Good viscoelastic temperature dependence is exhibited, good fixing properties are exhibited, and even if the contact charging device or the transfer rotary member is contaminated with toner, charging unevenness and transfer failure do not occur. It is considered that this is because when the toner adheres and is contaminated, it becomes difficult to form a thick adhered substance.

The type of the binder resin used in the present invention is, for example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like, or a substitution product thereof; styrene-p-chlorostyrene copolymerization. Coal, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene- Acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile- Styrene-based copolymers such as indene copolymers Combined; polyvinyl chloride, phenol resin, natural modified phenol 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.

A crosslinked styrene copolymer is also a preferable binder resin.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate,
Didecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a heavy bond or a substituted product thereof;
For example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like, and its substitution products; for example, vinyl esters such as vinyl chloride, vinyl acetate, vinyl benzoate and the like;
For example, ethylene-based olefins such as ethylene, propylene, butylene, etc .; for example, vinyl methyl ketone,
Vinyl ketones such as vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether and the like;
These vinyl monomers are used alone or in combination of two or more.

As the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used. For example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, Ethylene glycol dimethacrylate,
A carboxylic acid ester having two double bonds such as 1,3-butanediol dimethacrylate; a divinyl compound such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and a compound having three or more vinyl groups; Are used alone or as a mixture.

The colorants used in the present invention include carbon black, lamp black, iron black, ultramarine blue, nigrosine compound, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6G, chalco oil blue, chrome yellow. Conventionally known dyes and pigments such as quinacridone, benzidine yellow, rose bengal, triarylmethane compounds, monoazo dyes and disazo dyes may be used alone or in combination.

Examples of the magnetic material used in the present invention include iron oxides such as magnetite, γ-iron oxide, ferrite and iron-excessive ferrite; metals such as iron, cobalt and nickel; or metals such as these and aluminum and cobalt;
Examples thereof include alloys with metals such as copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof.

These ferromagnetic substances have an average particle size of 0.1 to 0.1.
1 μm, preferably 0.1 to 0.5 μm, is desirable. The amount contained in the magnetic toner is about 40 to 150 parts by weight with respect to 100 parts by weight of the resin component, and particularly preferably 100 parts by weight of the resin component. 60 to 120 parts by weight.

The toner of the present invention may be mixed with an additive, if necessary. Examples of the additives include lubricants such as zinc stearate, abrasives such as cerium oxide and silicon carbide, anti-caking agents, and conductivity-imparting agents such as carbon black and tin oxide.

Fluorine-containing polymer fine powder such as polyvinylidene fluoride fine powder is also a preferable additive from the viewpoint of fluidity, abradability, charge stability and the like.

For the purpose of improving releasability at the time of heat roll fixing, 0.5 to 5 wt% of wax-like substances such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, sazol wax and paraffin wax. % Is also one of the preferable modes of the present invention.

Further, the toner of the present invention can be mixed with a carrier and used as a two-component toner. As the carrier that can be used in the present invention, known carriers can be used, for example, iron powder, ferrite powder, magnetic powder such as nickel powder, glass beads, and the like, and the surface thereof is treated with a resin or the like. What you have done is listed. Further, as the resin coating the carrier surface, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, acrylic acid ester copolymer, methacrylic acid ester copolymer, silicone resin, fluorine-containing resin, A polyamide resin, an ionomer resin, a polyphenylene sulfide resin, or the like, or a mixture thereof can be used.

In producing the toner according to the present invention, the toner constituent materials as described above are thoroughly mixed by a ball mill or other mixing machine, and then thoroughly kneaded by using a heat kneader such as a hot roll kneader or an extruder. After cooling and solidification, a method of obtaining a toner by mechanical pulverization and classification is preferable. Alternatively, a method of obtaining a toner by dispersing constituent materials in a binder resin solution and then spray-drying; or a binder resin Polymerization toner production method in which a predetermined material is mixed with a monomer to be constituted to form an emulsion suspension, and then the toner is polymerized; or a so-called microcapsule toner including a core material and a shell material Alternatively, a method of incorporating a predetermined material into the shell material or both of them, and the like can be applied. Further, if necessary, desired additives can be sufficiently mixed with a mixer such as a Henschel mixer to produce the toner according to the present invention.

In the present invention, the molecular weight distribution by GPC of the THF soluble component of the toner is measured under the following conditions.

The column was stabilized in a heat chamber at 40 ° C., and THF was added as a solvent to the column at this temperature.
(Tetrahydrofuran) at a flow rate of 1 ml per minute,
About 100 μl of the THF sample solution is injected for measurement. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from a calibration curve (relationship between the logarithmic value of the molecular weight and the count number) prepared from several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, a product of Tosoh or Showa Denko having a molecular weight of about 10 ² to 10 ⁷ is used, and it is suitable to use at least about 10 points of a standard polystyrene sample.
An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns, for example, sho of Showa Denko KK
dex GPC KF-801, 802, 803, 80
Combination of 4,805,806,807,800P and TSKgel G1000H made by Tosoh Corporation
(H _XL ), G2000H (H _XL ), G3000H
(H _XL ), G4000H (H _XL ), G5000H
(H _XL ), G6000H (H _XL ), G7000H
(H _XL ), the combination of TSKguardcolumn can be mentioned.

The sample is prepared as follows.

The sample is placed in THF, left for several hours, shaken well, and mixed well with THF (until the coalescence of the sample disappears), and then allowed to stand for 12 hours or more. TH at this time
After leaving it in the F for 24 hours or more, the sample processing filter (pore size 0.45 to 0.
5 μm, for example, Maisori Disc H-25-5 manufactured by Tosoh, and Excicrodisc 25CR manufactured by Gelman Science Japan Co., Ltd.) can be used as a sample of GPC. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

As the contact charging means applicable to the present invention, the charging roller 12 as shown in FIG. 2 is preferable. As another means, the charging blade 1 as shown in FIG.
There are a method using 2'and a method using a conductive brush. These contact charging means have the effects of not requiring high voltage and reducing the generation of ozone, but
Since the member is in direct contact with the photoconductor, the problem of toner fusion is likely to occur, and it is most suitable for the present invention as a specific contact charging means. The present invention does not limit what kind of method the contact charging means to be applied has and what kind of effect it has, and any method of directly contacting a member with a photoconductor to charge it can be applied to the present invention. It is possible.

A preferable process condition when the charging roller is used is that the contact pressure of the roller is 5 to 500 g / c.
In m, when a DC voltage superimposed with an AC voltage is used, AC voltage = 0.5 to 5 kVpp, AC frequency = 50
˜5 kHz, DC voltage = −200 to −1.5 kV, and when DC voltage is used, DC voltage = −200 to −
It is 5 kV.

As a material for the charging roller and the charging blade, conductive rubber is preferable, and a releasing film may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), etc. can be applied.

As the material of the transfer rotary member applicable to the present invention, the same material as the charging roller can be used, and the preferable transfer process condition is that the contact pressure of the roller is 5 to 500 g / cm. And the DC voltage is 200
-10 kV.

[0085]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.
All parts in the following formulations are parts by weight.

(Synthesis Example 1) Styrene 80 parts n-Butyl acrylate 20 parts 2,2 Bis (4,4-di-t-0.2 parts butylperoxycyclohexyl) propane These are polymerized by suspension polymerization. I got A.

Styrene 83 parts Butyl acrylate 17 parts Di-t-butyl peroxide 1.0 part These were subjected to solution polymerization using xylene as a solvent to obtain a polymer B. The polymer A and the polymer B were mixed in a solution at a weight ratio of 30:70 to obtain a binder resin 1.

(Synthesis Example 2) Styrene 80 parts n-Butyl acrylate 20 parts 2,2 bis (4,4-di-t-0.1 part butylperoxycyclohexyl) propane These are polymerized by suspension polymerization. I got C.

Styrene 84 parts Butyl acrylate 16 parts Di-t-butyl peroxide 0.8 parts These were subjected to solution polymerization using xylene as a solvent to obtain a polymer D. The polymer C and the polymer D were mixed in a solution at a weight ratio of 25:75 to obtain a binder resin 2.

(Synthesis Example 3) Styrene 80 parts Butyl acrylate 20 parts Di-t-butyl peroxide 0.5 part These were subjected to solution polymerization using xylene as a solvent to obtain a binder resin 3.

Example 1 Binder Resin 1 100 parts Magnetite 80 parts Low molecular weight polypropylene wax 3 parts Compound Example (1) 2 parts After thoroughly mixing the above materials with a blender, use a twin-screw kneading extruder set at 150 ° C. Kneaded The obtained kneaded product is cooled and coarsely pulverized by a cutter mill, then finely pulverized by a fine pulverizer using a jet stream, and the obtained fine powder is divided into multi-division classifiers utilizing the Coanda effect (Japanese The fine powder and the coarse powder were strictly classified at the same time with an elbow jet classifier manufactured by Iron Mining Co., Ltd. to obtain a black fine powder having a weight average particle diameter of 8.3 μm.

On the other hand, the temperature is maintained at about 250 ° C. while stirring 100 parts of silica fine powder (specific surface area: about 200 m ² / g) synthesized by the dry method. Hexamethyldisilazane and silicone oil having a primary amine in the side chain are mixed at a ratio of 1/1 to obtain a treating agent. The silicone oil contains the structure of formula (III) as a constitutional unit.

[0093]

[Chemical 9] 30 parts of this treating agent was sprayed onto the silica fine powder and treated for 30 minutes.

This treated silica fine powder (specific surface area 16
0 m ^{2 /} g) 0.6 part and 100 parts of the black fine powder,
The mixture was mixed with a Henschel mixer to obtain a positively chargeable one-component magnetic toner. Table 1 shows the GPC measurement results of this toner.

Further, as shown in FIG. 2, a commercially available electrophotographic copying machine NP-2020 (manufactured by Canon Inc.) was modified.
A charging roller 12 made of a conductive rubber and connected to a power source 9 is disposed in contact with the photoconductor 1 to form a contact charging device, which uniformly charges the surface of the photoconductor. The contact pressure of the charging roller was 50 g / cm, and a DC voltage of -700 V and an AC voltage of 2.6 kVpp superimposed at 600 Hz were applied.

On the downstream side of the developing device 4 when viewed in the direction of rotation of the photoconductor, a transfer roller 15 formed of a conductive rubber similar to the charging roller is in pressure contact with the toner image on the surface of the photoconductor. At the same time, the transfer material is conveyed, and at this time, the transfer bias is applied to the transfer roller from the power source 9, and the toner image is transferred from the photoconductor to the transfer material. The contact pressure of the transfer roller was 20 g / cm, and a DC voltage of -4.5 kV was applied.

A copy test of 30,000 sheets was carried out on the above magnetic toner with the above modified NP-2020 machine. As a result, a clear image free from fog was obtained at an image density of 1.35 from the initial stage. The image after copying 30,000 sheets was also clear with a density of 1.38, and no image defect due to toner fusion was observed.

Example 2 Binder Resin 2 100 parts Magnetite 80 parts Low molecular weight polypropylene wax 3 parts Compound Example (2) 2 parts In the same manner as in Example 1 except that the weight average particle size was 8.
A black fine powder of 7 μm was obtained.

On the other hand, the temperature is maintained at about 250 ° C. while stirring 100 parts of silica fine powder (specific surface area: about 200 m ² / g) synthesized by the dry method. Dibutylaminopropyltrimethoxysilane and silicone oil having a primary amine in the same side chain as in Example 1 were mixed at a ratio of 2/1 to obtain a treating agent. 30 parts of this treating agent was sprayed onto the silica fine powder and treated for 30 minutes.

0.6 part of this treated silica fine powder was used in Example 1.
A single-component magnetic toner was obtained by mixing in the same manner as in. Table 1 shows the measurement results of GPC of this toner.

Using the same modified NP-2020 as in Example 1, a copying test was performed on the above magnetic toner on 30,000 sheets. As a result, the image density was 1.41 from the beginning.
A clear image without fog was obtained. The image after copying 30,000 sheets was also clear with a density of 1.40, and no image defect due to toner fusion was observed.

Comparative Example 1 Binder Resin 1 100 parts Magnetite 75 parts Low molecular weight polypropylene wax 3 parts Quaternary ammonium salt 5 parts From the above materials, in the same manner as in Example 1, weight average particle size 8.
8 μm black fine powder was obtained. The quaternary ammonium salt has a structure represented by the following formula (IV).

[0103]

[Chemical 10] This black fine powder and the same treated fine silica powder as in Example 1
Six parts were mixed in the same manner as in Example 1 to obtain a one-component magnetic toner. Table 1 shows the measurement results of GPC of this toner.

Using the same modified NP-2020 machine as in Example 1, a copy test was conducted on the above magnetic toner. As a result, a clear image with an image density of 1.31 and no fog was obtained in the initial stage, but after copying 10,000 sheets, image defects due to toner fusion of about several millimeters began to be seen. After that, the image defects became severe as the copying was continued, so the test was stopped.

Comparative Example 2 A one-component magnetic toner was obtained in the same manner as in Example 1, except that the binder resin 1 was changed to the binder resin 3. Table 1 shows the measurement results of GPC of this toner.

A copying test was conducted on this toner in the same manner as in Example 1. As a result, a clear image free of fog was obtained at an image density of 1.39 in the initial stage.
After copying 7,000 sheets, a few points of image defects due to toner fusion of several millimeters can be seen. After that, the image defects became severe as the copying was continued, so the test was stopped.

Example 3 A one-component magnetic toner was obtained in the same manner as in Example 1 except that the compound example (1) was changed to the compound example (3).

With respect to this toner, as in Example 1, 2
A copy test of 10,000 sheets was carried out. As a result, a clear image free from fog was obtained at an image density of 1.32 from the initial stage. The image after copying 20,000 sheets was also clear with a density of 1.33, and no image defect due to toner fusion was observed.

Example 4 A one-component magnetic toner was obtained in the same manner as in Example 1 except that the compound example (1) was changed to the compound example (4).

For this toner, as in Example 1, 2
A copy test of 10,000 sheets was carried out. As a result, a clear image free from fog was obtained at an image density of 1.36 from the initial stage. The image after copying 20,000 sheets was also clear with a density of 1.31, and no image defect due to toner fusion was observed.

Example 5 A one-component magnetic toner was obtained in the same manner as in Example 1 except that the treating agent for the fine silica powder was changed to 30 parts of silicone oil having a primary amine in the side chain.

With respect to this toner, as in Example 1, 2
10,000 copy tests were performed. As a result, a clear image free from fog was obtained at an image density of 1.40 from the initial stage. The image after copying 20,000 sheets was also clear with a density of 1.38, and no image defect due to toner fusion was observed.

Example 6 In Example 1, the silica fine powder was treated with 25 parts of hexyltrimethoxysilane per 100 parts of titanium oxide (hydrophobicity 60, specific surface area 90 m ^{2 /} g), and changed to 1.0 part. A one-component magnetic toner was obtained in the same manner except for the above.

For this toner, as in Example 1, 3
A copy test of 10,000 sheets was carried out. As a result, a clear image free from fog was obtained at an image density of 1.32 from the initial stage. The image after copying 30,000 sheets was also clear with a density of 1.37, and no image defect due to toner fusion was observed.

Example 7 A one-component magnetic toner was obtained in the same manner as in Example 1 except that only 20 parts of dibutylaminopropyltrimethoxysilane was used as the treating agent for the silica fine powder.

For this toner, as in Example 1, 2
A copy test of 5,000 sheets was conducted. As a result, a clear image with an image density of 1.41 and no fog was obtained from the initial stage. The image after copying 25,000 sheets was also clear with a density of 1.38, and no image defect due to toner fusion was observed.

Example 8 Binder resin 1 100 parts Carbon black 5 parts Low molecular weight polypropylene wax 4 parts Compound example (1) 2 parts A resin having a weight average diameter of 9.0 μm was prepared in the same manner as in Example 1 using the above materials. A fine powder was obtained. Obtained resin fine powder 1
To 600 parts of the silica fine powder used in Example 1 was mixed to prepare a toner.

Next, 94 parts of an acrylic-coated ferrite carrier having an average particle diameter of 55 μm and 6 parts of the obtained toner were mixed to prepare a developer.

For this developer, the N used in Example 1 was used.
With a modified P-2020 machine, use a developer for two components
A copy test of 10,000 sheets was carried out. As a result, a clear image free from fog was obtained at an image density of 1.38 from the initial stage. The image after copying 30,000 sheets was also clear with a density of 1.42, and no image defect due to toner fusion was observed.

[0120]

[Table 1]

[0121]

As described above, in the present invention, by containing the compound represented by the general formula (I) as a charge control agent, a sharp and appropriate charging property is exhibited, so that the toner for the photoreceptor is obtained. Fusing is suppressed. Further, since a binder resin having good viscoelastic temperature dependency is used, both prevention of toner fusion and good fixing property are achieved. Further, by using a fine powder of silica, alumina, or titania treated with a silane coupling agent and / or a silicone oil having a side chain containing a nitrogen atom, there is no chance of toner fusion.

As described above, each of them functions to prevent toner fusion, but in the present invention, a larger effect is exhibited than what is expected to be obtained by combining the respective effects. The configuration is very suitable for this.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a general electrophotographic apparatus.

FIG. 2 is a schematic configuration diagram of an electrophotographic apparatus having a charging roller as a contact charging unit.

FIG. 3 is a schematic configuration diagram of an electrophotographic apparatus having a charging blade as a contact charging unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Latent image carrier (photoreceptor) 4 Developing device 12, 12 'Charging means 15 Transfer roller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G03G 13/08 7810-2H G03G 9/08 371 374 (72) Inventor Hirohide Tanigawa Shimomaruko Ota-ku, Tokyo 3-30-2 Canon Inc.

Claims (4)

[Claims] 1. A toner comprising at least a resin particle containing at least a compound represented by the following general formula (I) or a compound obtained by laking the compound, a binder resin, and an inorganic oxide fine powder: ) The toner is
A toner for use in an image forming method, comprising: a contact charging unit that comes into contact with the surface of a latent image carrier and / or a rotating body for transfer that comes into contact with the surface of a latent image carrier, which is (b) TH of the toner.
In the molecular weight distribution by GPC (gel permeation chromatography) of the F-soluble content, at least one peak exists in the region of molecular weight 3,000 to 50,000, and at least one peak exists in the region of molecular weight 100,000 or more, A toner comprising 50 to 90% of a component having a molecular weight of 100,000 or less. [Chemical 1] [Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are the same or different from each other, a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl Represents a group. R ⁷ , R ⁸ and R ⁹ are each a hydrogen atom, a halogen atom, which may be the same or different,
It represents an alkyl group or an alkoxy group. A ^- is an anion such as sulfate ion, nitrate ion, borate ion, phosphate ion, hydroxide ion, organic sulfate ion, organic sulfonate ion, organic phosphate ion, carboxylate ion, organic borate ion, and tetrafluoroborate. Indicates. ] 2. The inorganic oxide fine powder is a fine powder of silica, alumina or titania treated with a silane coupling agent and / or a silicone oil having a side chain containing a nitrogen atom. Item 1. The toner according to Item 1. 3. An image forming method, comprising: a contact charging unit that contacts the surface of the latent image carrier and / or a rotating body for transfer that contacts the surface of the latent image carrier, wherein (a) the following general formula (I): A compound represented by or a compound obtained by laking it, and resin particles containing at least a binder resin, and at least containing an inorganic oxide fine powder, and
(B) The molecular weight distribution of the THF soluble component by GPC (gel permeation chromatography) shows a molecular weight of 3,000 to
There is at least one peak in the region of 50,000 and the molecular weight is 1
An electrostatic latent image held on the surface of the latent image holding member is developed by using a toner having at least one peak in a region of 0,000 or more and a component having a molecular weight of 100,000 or less of 50 to 90%. An image forming method characterized by the above. [Chemical 2] [Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are the same or different from each other, a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl Represents a group. R ⁷ , R ⁸ and R ⁹ are each a hydrogen atom, a halogen atom, which may be the same or different,
It represents an alkyl group or an alkoxy group. A ^- is an anion such as sulfate ion, nitrate ion, borate ion, phosphate ion, hydroxide ion, organic sulfate ion, organic sulfonate ion, organic phosphate ion, carboxylate ion, organic borate ion, and tetrafluoroborate. Indicates. ] 4. The fine powder of inorganic oxide is a fine powder of silica, alumina or titania treated with a silane coupling agent and / or a silicone oil having a side chain containing a nitrogen atom. Item 4. The image forming method according to Item 3.