JP3451854B2 - One-component developer and image forming method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-component developer for developing an electrostatic latent image on a latent image carrier and an image forming method using the same.

[0002]

2. Description of the Related Art In recent years, as an electrophotographic dry developing system, not only an electrostatic copying machine but also a printer, a facsimile machine, or a multifunction machine having a copying machine and a printer / facsimile machine has been used. In particular, as a recent trend, there is a strong demand for smaller size, lighter weight, ecological measures such as resource saving and recycling. In order to deal with this, improvement and new development of the image forming method and the developer used therefor have been carried out. At present, as a dry developing method in various electrostatic copying methods which have been put into practical use, a two-component developing method using a carrier such as toner particles and iron powder and a one-component developing method not using a carrier are known.

The two-component developing method is the most widely used method, but the toner particles adhere to the surface of the carrier to deteriorate the developer, and a clear image can be retained for a long period of time. In addition to having the drawbacks such as not being possible, it is necessary to have a toner concentration control system that keeps the concentration ratio of toner in the developer constant and a mixing device that mixes the toner newly added to the developer with the developer. However, it has a drawback that the developing device becomes large.

Therefore, as a developing system, there is an increasing demand for a one-component developing system which is characterized in that the developing device is small and lightweight, and the toner density adjusting system is not troublesome. At present, the developing system has become the mainstream. It's starting. The one-component toner developing method is classified into a magnetic one-component developing method using a magnetic toner and a non-magnetic one-component developing method using a non-magnetic toner.

In the magnetic one-component developing method, a developer carrying member having a magnetic field generating means such as a magnet provided therein is used to hold and develop the magnetic toner, and the toner transfer control is easy. In recent years, many have been put to practical use because of less internal pollution of copying machines, printers and the like. However, since the magnetic toner used in the magnetic one-component developing system contains a colored magnetic material such as black or brown such as magnetite in its interior, there is a serious drawback that it cannot be applied to full-colorization, which is increasing in demand in the market in recent years. is there. Further, the magnetic one-component developing device has to include a magnet inside the developing roll, and therefore, there is a limit to downsizing of the developing roll, and thus there is a limit to downsizing of the developing device.

On the other hand, in the non-magnetic one-component developing system, since a magnetic material is not used for the toner, colorization is possible, and
Since no magnet is used for the developer carrying member, it is possible to reduce the weight, size, and cost. However, in the two-component developing method, there is a stable charging and conveying member called a carrier, and in the magnetic one-component developing method, there is a stable conveying and layer forming means such as a magnetic force of a magnet roll, whereas in the non-magnetic one-component developing method. In the method, since there is no such stable charging and conveying means, it is necessary to stably supply / hold the toner on the developer carrying member only by the electrostatic force to charge / develop the toner.

Therefore, the toner of the non-magnetic one-component developing system is required to have higher and more severe characteristics (rapid and uniform charging, better fluidity, etc.). That is, the non-magnetic one-component toner has to be charged / conveyed within a short contact time with the blade or the sleeve, and has a higher charging rate than a normal magnetic one-component toner or a two-component toner and a high charging speed (a rapid charging (Rise) is required. Further, the non-magnetic one-component toner is charged mainly by the contact friction with the blade / sleeve, but when the toner component is contaminated on those charging members, it is charged and deteriorated like the carrier of the two-component developer. Occurs, the density is reduced due to the decrease in charge, the background is fogged, the inside of the machine is stained, etc., and especially when the toner component is attached to the blade, streak-shaped image defects are caused. Therefore, in order to provide the non-magnetic one-component toner with high maintainability, in addition to the above-mentioned high charging ability and high charging speed, the property of low adhesion is strongly required.

Conventionally, in order to stabilize the charging and carrying of toner, and to improve the fluidity and charging property,
For example, fine powder of inorganic oxide such as silica is added to the toner. However, the commonly used silica-based fine powder is effective for improving the fluidity of the toner, but excessively increases the charge of the negatively chargeable toner under low temperature and low humidity, while it increases under high temperature and high humidity. Absorbs water and reduces the chargeability, so that the chargeability varies greatly depending on the environmental conditions used. As a result, it is not possible to secure the transportability of the toner onto the developer carrying member and the optimum charging property under both high temperature and high humidity and low temperature and low humidity, and it is not possible to reproduce the image density, background fog, and toner flapping. In addition, there is a problem of causing in-flight pollution and the like.

In order to solve these problems, it has been proposed to use surface-treated inorganic fine powder as the inorganic fine powder added to the toner. For example, JP-A-46-5782
JP-A-48-47345, JP-A-48-
47346, JP-A-59-34539, JP-A-59-198470, and JP-A-59-231.
Japanese Patent No. 550, etc. describes that the surface of silica fine particles is subjected to a hydrophobic treatment. However, the use of these inorganic fine powders alone does not provide sufficient performance in terms of charging property, and there is no advantage particularly in the case where a polyester resin is used as the binder resin. That is,
In a case where sufficient chargeability can be imparted at high temperature and high humidity, the amount of conveyance on the developer carrying member becomes excessive to impart excessive charge at low temperature and low humidity, and broadening of charge becomes severe, In particular, the developability is lowered and the fog ratio is increased.

The toner to which silica fine particles are externally added is
Generally, regardless of whether it is a two-component system or a one-component system, the charging rise is slow.
Even under low temperature and low humidity where high charge can be obtained, there is a drawback that fog and toner cloud (contamination inside the machine) are likely to occur due to the opposite polarity toner. Furthermore, even in a good environment, when used for a long period of time, the toner component adheres to the blade portion and uniform conveyance cannot be performed. This results in fluffing, contamination in the machine, and the like. This also applies to the case of using silica treated with a silicone oil of a low surface energy substance as described in JP-A-61-277964. Occur. Further, the fine silica powder has a wide charge distribution on the developer carrying member mainly due to high resistance, high chargeability, slow charging speed, etc., and the charge amount is temporarily within an appropriate range. In addition, since it also has drawbacks such as the generation of a large amount of reverse polarity toner,
Fogging due to reverse polarity toner and toner cloud (dirt inside the machine) will occur. As described above, even if the silica fine particles are subjected to a hydrophobic treatment, a treatment to alleviate the negative chargeability, etc., they have not been able to improve the environmental dependence of the charge of silica, the charge speed, and the poor charge distribution. At present, the problem of reducing the adhesion to the charging member has not been improved yet.

In addition, it may be because titania generally used as an inorganic oxide added for the purpose of improving the chargeability and fluidity of the toner has a faster charging rise than silica and has a low resistance. It has the characteristic that the charge distribution is sharp. However, when titania is used, high charge cannot be imparted to the toner, and the toner conveyance amount is reduced, density reproducibility is reduced due to reduction in charge, and background fogging is likely to occur. Therefore, for the purpose of improving the charging property, a method has been proposed in which hydrophobic titanium oxide is externally added to the toner regardless of whether it is a two-component system or a one-component system (JP-A-58).
-216252, JP-A-60-123862, JP-A-60-238847). This hydrophobic titanium oxide is obtained by treating the surface with a silane compound, a silane coupling agent, silicone oil, or the like. According to this method, the chargeability can be improved more than that of the untreated hydrophilic titania, and it is used for the two-component toner and the magnetic one-component toner, and is actually put on the market.

However, in the non-magnetic one-component toner, a certain amount of charge can be improved depending on the type and amount of the treating agent, but the amount of charge is not yet at a satisfactory level and the environmental dependence is limited. is there. Further, when the hydrophobicity of titanium oxide is increased by using a treating agent, the charging level and the environmental dependence are certainly improved as compared with the conventional hydrophilic titanium oxide, but conversely, the charging rate and charging property of titanium oxide are increased. In reality, the sharpness of the distribution is much lower than that of conventional titanium oxide.

Titanium oxide is obtained mainly by a method of extracting titanium oxide crystals from an ilmenite ore by a sulfuric acid method or a hydrochloric acid method. The crystals are obtained by refining by a wet method, heating and firing. In addition, naturally there will be chemical bonds generated by dehydration condensation.
It is not easy to redisperse such aggregated particles. In particular, the titanium oxide extracted as fine powder is secondary,
Since the third-order aggregation is formed, the effect of improving the fluidity of the toner is significantly inferior to that of silica.

In recent years, there is an increasing demand for high image quality, especially in color images, and along with this, attempts have been made to achieve high image quality by reducing the toner particle size. The phenomenon in which the adhesive force increases and the fluidity of the toner is reduced will be further expanded. Further, titanium oxide which has been conventionally used has a drawback that it cannot be firmly attached to the toner surface and is easily peeled off from the toner surface, probably because the specific gravity is larger than that of silica. As a result, the long-term charge stability associated with sleeve contamination and blade contamination is poor, and contamination of the photoconductor is also likely to occur, which causes image quality deterioration and image quality defect.

Further, in order to improve the fluidity of the toner and achieve the environmental independence of charging, a combination of hydrophobic titanium oxide and hydrophobic silica has been proposed as an external additive.
(JP-A-60-136755). According to this method, although the drawbacks of the hydrophobic silica and the hydrophobic titanium oxide are temporarily suppressed, it becomes easy to be influenced by either one of the additives depending on the dispersion state, and in particular the durability is ensured. In addition, it is difficult to stably control the dispersion structure on the toner surface, and when stress is applied on the sleeve, defects of either hydrophobic silica or hydrophobic titanium oxide are likely to appear. It was difficult to control it stably.

Next, a method of adding a hydrophobic amorphous titanium oxide to a toner has been proposed (Japanese Patent Laid-Open No. 5-20).
No. 4183, JP-A-5-72797). Amorphous titanium oxide can be obtained by hydrolyzing a metal alkoxide or a metal halide using a CVD method (Chemical Engineering Papers, Vol. 18, No. 3, 30).
3 to 307 (1992)). However, although the titanium oxide obtained by such a hydrolysis method can achieve both charging characteristics and improved toner fluidity, it has a large amount of adsorbed water inside the particles, so that it itself becomes a photoreceptor during transfer. It will remain. That is, since amorphous titanium oxide has a strong adhesive force with the photoconductor, only the amorphous titanium oxide remains on the photoconductor without being transferred, and white titanium spots on the image or the hard titanium oxide scratches the photoconductor surface during cleaning. There are drawbacks such as.

On the other hand, as a method for purifying titanium oxide by a wet method, the silane compound is hydrolyzed in an aqueous medium, the surface treatment of titanium oxide is carried out, and the titanium oxide is taken out in a state where aggregation is suppressed. Has been proposed (Japanese Patent Laid-Open No. 5-188633). When the silane compound is treated by this method, the fluidity of the toner is improved because the number of aggregated particles is reduced as compared with the conventional hydrophobizing method of titanium oxide, but the charge level and the environmental dependence of the negatively charged toner are different from those of the conventional method. There is no change, and the high negative chargeability and environmental dependence are not sufficient,
Furthermore, the charging speed (addition property of additional toner) and charge distribution are adversely affected.

Furthermore, when the above-mentioned inorganic oxide is added to the toner surface and continuously used for a long period of time, stress is applied to the toner by the layer forming member and the like, toner filming and fusion occur on the layer forming member, and external addition is performed. Since the chargeability of the toner changes due to peeling or embedding of the agent, it becomes difficult to maintain stable charge and transport of the toner for a long period of time. As a means for solving these problems, Japanese Patent Laid-Open No. Hei 6
-95429, JP-A-6-102699,
JP-A-6-266156 proposes to use a specific binder resin in order to prevent the external additive from being embedded. Further, JP-A-6-51561, JP-A-6-208242, and JP-A-6-250.
For example, Japanese Patent Laid-Open No. 442 proposes to use a specific charge control agent or an external additive. However, none of these methods is satisfactory, and particularly in a full-color development system that superimposes four colors, it is necessary to control the development amount of toner more precisely, and therefore the charge amount of toner is reduced. In addition, many problems still remain for the long-term stabilization of the transport amount.

[0019]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has as its object to solve the problems. That is, the first object of the present invention is to stabilize the charging and conveyance of toner for a long period of time,
It is an object of the present invention to provide a one-component developer capable of obtaining stable image density. A second object of the present invention is to provide a one-component type developer which does not exhibit low developability, fog, etc. for a long period of time, and is resistant to filming and fusion. Further, a third object of the present invention is to provide an image forming method using a one-component developer capable of obtaining stable and excellent image quality for a long period of time.

[0020]

Means for Solving the Problems As a result of earnest studies on a one-component developer, the present inventors have found that a specific titanium compound is used as an external additive for toner particles containing a binder resin and a colorant. By using a reaction product obtained by the reaction with a silane compound, it was found that stable and clear image quality without concentration change, fog, filming, etc., can be obtained for a long time, and the present invention is completed. I arrived.

That is, the one-component developer of the present invention is a one-component developer comprising toner particles containing a binder resin and a colorant, and an additive, wherein the additive is TiO 2.
It is characterized by containing a titanium compound obtained by reacting a part or all of (OH) ₂ with a fluorine-containing silane compound. Further, the image forming method of the present invention is an image forming method having a step of forming a latent image on a developer carrying member and a step of developing the obtained latent image with a developer on the developer carrying member. As the developer, TiO is added to the toner particles.
It is characterized in that a one-component developer externally added with a titanium compound obtained by the reaction of (OH) ₂ and a fluorine-containing silane compound is used.

The titanium compound used as an additive (external additive) of the above-mentioned developer may be produced from a fluorine-containing silane compound represented by the following formula (1) or (2) as a raw material. preferable. _{C n F 2n + 1 CH 2} CH 2 Si (CH 3) p X 3-p (1) ( wherein, X represents a hydrolyzable group, n represents 1, 4, 6, 8
Or 10 and p is 0 or 1. _{) C m F 2m + 1 -Ph} -CH 2 CH 2 Si (CH 3) q Y 3-q (2) ( wherein, Ph is a phenylene group, Y represents a hydrolyzable group, m is 1,4 , 6 or 8, and q is 0 or 1.)

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The one-component developer of the present invention forms a thin layer of the developer on the developer carrier, conveys the obtained thin layer of the developer to the developing section, and forms the electrostatic latent image on the latent image carrier. The image forming method is used for an image forming apparatus for developing, and the image forming method includes a latent image forming step of forming a latent image on at least a latent image holding member, and a developer formed in a thin layer on a developer carrying member. Developing process for developing a latent image on the latent image holding member by using a toner, a transfer process for transferring a developer (toner) image on the latent image holding member to a transfer member, and a fixing for thermally fixing the toner image on the transfer member. It has a process.

A conventionally known method can be applied to the latent image forming step, and an electrostatic latent image is formed on a latent image support such as a photosensitive layer or a dielectric layer by an electrophotographic method or an electrostatic recording method. To do. The latent image carrier used in the present invention is a conventionally known one in which a photosensitive layer is formed on a cylindrical support, and as the photosensitive layer, a known photoconductive material such as organic type or amorphous silicon is used. Things can be used. As the cylindrical support, a support made of a conductive substrate and obtained by a known production method such as extrusion molding of aluminum or aluminum alloy and surface treatment is used.

In the developing step, a developer carrier (developing roll)
The toner is formed into a thin layer on the rotating cylindrical body of by an elastic blade or the like, and the toner is conveyed to the developing unit, and the developing roll and the latent image holding member for holding the electrostatic latent image are brought into contact with each other or fixed in the developing unit. The electrostatic latent image is developed using toner while applying a bias between the developing roll and the latent image holding member by providing a gap. The developer carrying member used in the present invention includes an elastic sleeve such as silicone rubber, a sleeve obtained by drawing out metal or ceramics such as aluminum, SUS stainless steel, nickel or the like, or a substrate surface for controlling toner transportability and chargeability. Surface treatment such as oxidation or metal plating, polishing, blasting, etc., coating with resin, etc., especially aluminum, S
When a sleeve made of metal such as US stainless steel or nickel or a ceramic is drawn out, the advantage of the present invention is remarkably improved because long-term charging property is obtained by reducing toner adhesion to the sleeve.

To form a toner layer on the developing roll,
This is done by bringing the elastic blade into contact with the sleeve surface. As the material of the elastic blade, it is preferable to use a rubber elastic body such as silicone rubber or urethane rubber, and an organic or inorganic material may be added and dispersed in the elastic body in order to control the toner charge amount.

In the transfer step, the toner image on the latent image holding member is transferred to the paper which is the transfer member. As the transfer means in the present invention, there are used known means such as a contact type in which a transfer roller is brought into pressure contact with a latent image holding member and a non-contact type in which a corotron is used. The type is commonly used. The cleaning step removes the toner remaining on the latent image holding member without being transferred in the transfer step with a cleaner. As the cleaning means in the present invention, a known device such as blade cleaning or roller cleaning is used. Elastic rubber such as silicone rubber or urethane rubber is used for the blade cleaning. In the fixing step, the toner image transferred onto the transfer body is fixed by a fixing device, and as the fixing means, a heat fixing method using a heat roll is usually used.

The one-component type developer in the present invention comprises toner particles containing at least a binder resin and a colorant and an additive for coating the outer surface thereof, and the additive is a wet method. It is necessary to use a titanium compound produced by the reaction of a part or all of the resulting TiO (OH) ₂ with a fluorine-containing silane compound. In the present invention, the titanium compound used as an additive preferably has a specific gravity in the range of 2.8 to 3.6.

In the present invention, it is preferable to use the fluorine-containing silane compound represented by the following formula (1) or (2). _{C n F 2n + 1 CH 2} CH 2 Si (CH 3) p X 3-p (1) ( wherein, X represents a hydrolyzable group, n represents 1, 4, 6, 8
Or 10 and p is 0 or 1. _{) C m F 2m + 1 -Ph} -CH 2 CH 2 Si (CH 3) q Y 3-q (2) ( wherein, Ph is a phenylene group, Y represents a hydrolyzable group, m is 1,4 , 6 or 8, and q is 0 or 1.) In the formulas (1) and (2), the hydrolyzable group may be any functional group capable of being decomposed by water, It is preferably a halogen atom such as chlorine atom or an alkoxy group such as methoxy or ethoxy group.

In general, the conventional method for producing titanium oxide by the wet method is one which is produced by a chemical reaction in a solvent and is classified into a sulfuric acid method and a hydrochloric acid method. Among them, in the sulfuric acid method, the following reaction proceeds in the liquid phase and insoluble TiO (OH) ₂ is obtained by hydrolysis. FeTiO ₃ + 2H ₂ SO ₄ → FeSO ₄ + TiOSO
₄ + 2H ₂ O TiOSO ₄ + 2H ₂ O → TiO (OH) ₂ + H ₂ SO
_{4 In} the hydrochloric acid wet method, first, chlorination is performed by the same method as in the dry method to produce titanium tetrachloride, and then it is dissolved in water and hydrolyzed by adding a strong base to the TiO (OH ) ₂ is obtained. The chemical formula for this is as follows. TiCl ₄ + H ₂ O → TiOCl ₂ + 2HCl TiOCl ₂ + 2H ₂ O → TiO (OH) ₂ + 2HCl

Further, in the usual production process of titanium oxide, titanium oxide is obtained by subsequently repeating washing with water and filtration and firing. If necessary, crush,
After crushing, the same treatment as in the silane compound is performed. However, the conventional manufacturing method of this titanium oxide is T
Since i is strongly bonded to each other, there is a serious drawback that particles are sintered in the firing step and a large number of aggregates are generated. In order to solve this problem, many contrivances have been made for strengthening wet pulverization, reaction with a treating agent before drying, etc., but at present, it is impossible to crush this agglomerate to primary particles. Even if the titanium oxide thus obtained is applied to the additive of the toner particles and the coverage on the toner particles is secured by combining with the silica particles, the same fluidity as in the case of using silica cannot be obtained. In addition, the photosensitive material scratches and filming due to the aggregation will occur.

The titanium oxide obtained by the conventional manufacturing method is
There is a limit to the amount that can be treated with a silane compound. Generally, when the amount of the silane compound used is increased, the chargeability-imparting ability is increased, but the limit of the ability is reached at a treatment amount of about 15 to 20% by weight with respect to titanium oxide.
Therefore, if the amount of the coupling agent is increased in order to impart the high charge, not only the high charge cannot be obtained, but also the excess coupling agents react with each other to further increase the aggregated particles. If it is added to the toner particles, the charging speed may be lowered and the charging distribution may be broadened.
As described above, conventionally used titanium oxide has many agglomerated particles, and none of them has a high charge imparting ability, a low charging speed and a charge distribution.

The titanium compound used in the present invention is obtained by reacting TiO (OH) ₂ produced in the above wet process with a silane compound and then drying.
In this method, there is no high temperature firing step of several hundred degrees,
There is no agglomeration because strong bonding between titanium does not occur,
The particles can be taken out in the state of almost primary particles, and this titanium compound can be treated in a large amount because the silane compound can be directly reacted with TiO (OH) ₂ .

This titanium compound has a higher treatment amount limit value that contributes to the charging ability than the conventional treated titanium oxide, and even if it depends on the particle size of the raw material, it is about three times as much as the conventional product ( It has an advantage that it can be treated up to about 50 to 70% with respect to the titanium raw material. Therefore, the charging amount of the toner can be controlled by the treatment amount of the silane compound, and the charging ability that can be imparted is the same as that of the conventional titanium oxide. It can be improved significantly. Further, since the surplus silane compound can be reduced, that is, the reaction between the silane compounds is reduced, a high charge can be obtained without lowering the charging speed and the charge distribution even when the processing amount is increased.

Further, since this titanium compound does not migrate to the sleeve and does not migrate the processing agent, the contamination of the sleeve is small, the toner charge on the developer carrier does not change for a long time, and the photosensitive material is not used. There is no adhesion to the top, and no image quality defect occurs for a long time. Since this is a light titanium oxide having a specific gravity of 2.8 to 3.6, it adheres firmly to the surface of the toner, and as a result, it is not detached from the toner even if it is used for a long period of time. There is little reaction between silane compounds with each other (it adheres firmly to the drug substance)
This is because the transfer of processing agent is small. The titanium compound used in the present invention has an average primary particle size of 10
It is 0 nm or less, preferably in the range of 10 to 70 nm.

In the present invention, in order to produce the above titanium compound, some or all of the silane compound,
The fluorine-containing silane compound represented by the above formula (1) or formula (2) is used as a treating agent. By using this fluorine-containing silane compound, the adhesiveness of the external additive and / or toner to the blade, which is the charging member, is significantly reduced, and the image does not have streaks due to poor conveyance, and the density is maintained for a long time. Excellent reproducibility and good image quality without background fog can be obtained. The fluorine-containing silane compound represented by formula (1) or formula (2) is used in the range of 5 to 100% by weight based on the total silane compound used. If the amount is 5% by weight or less, streak-like image quality deterioration occurs due to toner contamination of the blade when used for a long period of time, and further background fog, which is considered to be due to the low charging property of the streak part, occurs. It is assumed that the fact that the fluorine-containing silane compound is contained even in a part of the silane compound is effective for blade adhesion is due to the presence of the fluorine-containing silane compound in the outermost surface layer of the titanium compound. It

Since the demand for high image quality has recently increased, the toner tends to have a smaller particle size, and in order to improve the transfer failure due to the increase in the adhesive force due to the smaller particle size, a large particle size is used. Silica or titania is used as a second external additive (transfer aid). However, the titanium compound used in the present invention can be used even when such a transfer aid having a large particle size is added. For example, by using the titania compound having a large particle size in combination with the titanium compound used in the present invention, the low charge generated due to the addition of the second external additive, the environmental dependency and the decrease in the admix property (repeated use for a long period of time) It is possible to obtain good transferability without deteriorating the charge distribution due to the above, and without lowering the charge imparting ability due to the long-term stress generated by peeling of the treatment agent.

In the present invention, in addition to the fluorine-containing silane compounds represented by the above formulas (1) and (2), silane compounds used for the treatment of titanium compounds include chlorosilane, alkoxysilane, silazane and special silyl compounds. Agents can be used. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, hexamethyldisilazane,
N, O-bis (trimethylsilyl) acetamide, N,
N-bis (trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane,
γ-methacryloxypropyltrimethoxysilane, β-
(3,4-Epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-
Examples include, but are not limited to, chloropropyltrimethoxysilane.

The amount of the above treating agent used is TiO (OH) ₂
Generally, TiO depends on the primary particle size of the
The amount of the silane compound is in the range of 10 to 80 parts by weight, more preferably 20 to 50 parts by weight, based on 100 parts by weight of the (OH) ₂ raw material. When the amount of treatment is less than 10 parts by weight, the treatment function of the silane compound cannot be exhibited, and when the amount of treatment exceeds 80 parts by weight, the surplus silane compound is turned into oil, resulting in poor fluidity of the toner. Occurs. However, the treatment with the silane compound is intended to impart a high charge to the toner, improve the environmental dependency, improve the fluidity of the toner, reduce the interaction within the photosensitive material, and reduce the blade adhesion during long-term use. Therefore, the treatment amount is appropriately adjusted by comprehensively examining the particle size and surface area of the toner particles, the developer carrier, and the TiO (OH) ₂ raw material used.

The amount of the additive (titanium compound) added to the toner particles varies depending on the particle size of the toner particles, the composition of the developer carrying member, etc., but is 0 with respect to 100 parts by weight of the toner. 0.1 to 5.0 parts by weight, preferably 0.2 to 2.0 parts by weight. If the amount is less than 0.1 part by weight, the fluidity of the toner will be insufficient, and
If it exceeds 0 parts by weight, the fixing temperature will be raised and the fixing strength will be lowered in the fixing step, and when used in full color, the light-transmitting property will be lowered and the color development of the superposed base color will be disturbed. become.

In the developer of the present invention, as the toner particles, known ones composed mainly of a binder resin and a colorant are used. As those used as the binder resin, styrene, styrenes such as chlorostyrene, ethylene, propylene, butylene, monoolefins such as isoprene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl esters such as vinyl butyrate, Α-methylene aliphatic monocarboxylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, etc. , Vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether, and other vinyl ethers, vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone, and other vinyl ketones, and homopolymers or copolymers thereof Although exemplified, particularly, as a typical binder resin, polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, Examples thereof include styrene-maleic anhydride copolymer, polyethylene and polypropylene, and further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin and paraffin wax.

As the colorant used in the toner, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride,
Phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 1
2: 2, C.I. I. Pigment Red 57: 1, C.I.
I. Pigment Yellow 97, C.I. I. Pigment
Yellow 12, C.I. I. Pigment Blue 15: 1,
C. I. Pigment Blue 15: 3 and the like can be illustrated as a typical example.

A charge control agent may be added to the one-component developer in the present invention, if necessary. As the charge control agent, a known one can be used, but a fluorine-based surfactant,
Metal salicylate complex, metal-containing dye such as azo metal compound, polymer acid such as copolymer containing maleic acid as a monomer component, quaternary ammonium salt, azine dye such as nigrosine, carbon black or charge control Although a resin or the like is used, it is particularly preferable to use a salicylic acid complex of Zn or Al metal or a quaternary ammonium salt in the range of 0.1 to 10 wt%.

Further, a releasing agent may be added to the developer in order to improve the offset resistance. As the releasing agent used, paraffins having 8 or more carbon atoms, polyolefins and the like are preferable, and examples thereof include paraffin wax, paraffin latex, microcrystalline wax, polypropylene, polyethylene and the like, which may be used alone or in combination. , The addition amount is 0.3
The range of 10 to 10% by weight is preferable. The volume average particle diameter of the developer is preferably 3 to 15 μm, more preferably 5 to 10 μm. If the volume average particle diameter is less than 3 μm, the fluidity is remarkably reduced, so that the layer cannot be formed satisfactorily, causing fog and dirt. On the other hand, if the volume average particle diameter is 15 μm or more, the resolution is lowered and high image quality cannot be obtained.

The developer of the present invention can be produced by any known method, but the one produced by a kneading and pulverizing method is particularly preferable. That is, the binder resin, the colorant and the like are melt-kneaded using a kneader such as a kneader or an extruder, cooled, crushed, and classified into toner particles obtained by adding the above-mentioned additives. The method of mixing and manufacturing is preferable.

In the present invention, the titanium compound is added to the toner particles and mixed, and the mixing can be carried out, for example, by a V-type blender, a Henschel mixer, a Loedige mixer or the like. At that time, if necessary, various additives may be added, and examples of the additive include other fluidizing agents, cleaning aids such as polystyrene microparticles, polymethylmethacrylate microparticles, and polyvinylidene fluoride microparticles, or transfer aids. Agents and the like. Further, if necessary, coarse particles of toner may be removed using a vibration sieving machine, a wind sieving machine, or the like.

The charge amount of the developer of the present invention was 100 μm using a blow-off charge amount measuring instrument manufactured by Toshiba Chemical Co.
30 g of iron powder of m and 1.2 g of toner were stirred for 60 seconds with a Turbula mixer and then measured. Measurement environment is temperature 22
It was conducted at ° C / humidity of 55% RH. The particle size of the toner was measured with a particle size measuring instrument TAII manufactured by Coulter Counter Co., Ltd. and an aperture diameter of 100 μm. The specific gravity of the titanium compound used in the present invention is determined by JI using a Le Chatelier specific gravity bottle.
It was measured according to SK-0061,5-2-1. The operation method is as follows. (1) Add about 250 ml of water to the Le Chettelier pycnometer,
Adjust so that the meniscus is on the scale. (2) Immerse the pycnometer in a constant temperature water bath until the liquid temperature is 20.0 ± 0.
When the temperature reached 2 ° C, read the position of the meniscus accurately on the scale of the pycnometer. (Precision is 0.025 ml) (3) About 100 g of the sample is weighed to the order of 1 mg, and its mass is W. (4) Put the weighed sample in a pycnometer and remove bubbles. (5) Immerse the pycnometer in a constant temperature water bath and adjust the liquid temperature to 20.0 ±
Keep at 0.2 ° C and read the position of the meniscus accurately on the scale of the pycnometer. (Accuracy is 0.025 ml) (6) Specific gravity is calculated by the following formula. _{D = W / (L 2 -L} 1) in S = D / 0.9982 [wherein, D: density of the sample (20 ℃) (g / cm 3),
S: specific gravity of the sample (20/20 ° C), W: apparent mass of the sample (g), L ₁ : reading of meniscus before placing the sample in the specific gravity bottle (20 ° C) (ml), L ₂ : sample Reading of the meniscus after placing in a pycnometer (20 ° C) (ml). ] 0.9982 in the above formula means the density (g / cm ³ ) of water at 20 ° C.

[0048]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following description, all "parts" mean "parts by weight" unless otherwise specified. The present invention is
Titanium oxide produced by the wet method, that is, titanium oxide produced by the sulfuric acid method and the hydrochloric acid method can be used, but here, ilmenite ore is used as titanium oxide,
Ilmenite ore is dissolved in sulfuric acid to separate iron, and the TiOSO ₄ thus obtained is hydrolyzed to TiO (OH) ₂
The wet precipitation method was used to generate In this method, what is important is hydrolysis for generating nuclei and dispersion adjustment / aggregation adjustment and washing with water. Particularly, pH adjustment (acid neutralization) in dispersion treatment / aggregation adjustment and adjustment of slurry concentration are Since it determines the primary particle size of the titanium compound thereafter, a high level of control is required.

[Production of Additives for Toner Particles] (Preparation of External Additive A) TiO (OH) produced by the above method
₂ 100 parts by weight, 40 parts by weight of isobutyltrimethoxysilane and a fluorine-containing silane compound (structural formula: C ₈ F ₁₇ CH
₂ CH ₂ Si (OCH ₃ ) ₃ ) 10 parts by weight are mixed, and 6
Heat to 0 ° C. to react. Then, it was washed with water, filtered, dried at 120 ° C., and the soft agglomeration was released by a pin mill to obtain a titanium compound A having an average primary particle size of 40 nm and a specific gravity of 3.2. (Adjustment of External Additive B) In the adjustment of the external additive A, an average primary particle diameter of 25 n was obtained by the same method as that of the external additive A except that pH adjustment and dispersion / aggregation adjustment were replaced for particle diameter adjustment.
A titanium compound B having m and a specific gravity of 3.2 was obtained. (Adjustment of External Additive C) External Additive A except that the addition amount of isobutyltrimethoxysilane was changed to 10 parts by weight and the addition amount of the fluorine-containing silane compound was changed to 40 parts by weight in the adjustment of the external additive A. An average primary particle size of 45n
A titanium compound C having m and a specific gravity of 3.2 was obtained. (Adjustment of External Additive D) External Additive A except that the addition amount of isobutyltrimethoxysilane was changed to 20 parts by weight and the addition amount of the fluorine-containing silane compound was changed to 5 parts by weight in the adjustment of the external additive A. Average primary particle size 40n
A titanium compound D having a specific gravity of 3.4 and a specific gravity of 3.4 was obtained.

(Preparation of External Additive E) In the preparation of the external additive B, isobutyltrimethoxysilane was replaced with decyltrimethoxysilane, and the fluorine-containing silane compound was replaced by a structural formula: CF ₃ CH ₂ CH ₂ Si (OCH). ₃₎ except that instead of ₃ ones, the average in the same manner as the external additive B primary particle size 25 nm, to obtain an external additive E specific gravity 3.3. (Adjustment of external additive F) TiO (OH) produced by the above method
₂ 100 parts of fluorine-containing silane compound (structural formula: CF
50 parts by weight of ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ) are mixed and heated to 80 ° C. to react. Then, the product was washed with water, filtered, dried at 120 ° C., and soft aggregated by a pin mill to obtain a titanium compound F having an average primary particle size of 25 nm and a specific gravity of 3.4. (Adjustment of External Additive G) TiO (OH) produced by the above method
₂ was washed with water, filtered, and then baked at 650 ° C. to obtain titanium oxide having an average primary particle size of 40 nm. Then, pulverize with a jet mill, and then disperse in methanol to make titania 1
40 parts by weight of isobutyltrimethoxysilane and 100 parts by weight of fluorine-containing silane compound (structural formula: C ₈ F ₁₇ CH ₂ C
After mixing 5 parts by weight of H ₂ Si (OCH ₃ ) ₃ ) and wet pulverizing with a sand grinder, the solvent is removed with stirring with a kneader, and the external additive G (specific gravity: 3.
9) was obtained.

(Preparation of External Additive H) T produced by the above method
The iO (OH) ₂ was washed with water, filtered, and then fired at 650 ° C. to obtain titanium oxide having an average primary particle size of 25 nm. Then, it is again dispersed in toluene, wet-milled using a sand grinder, and then 100 parts by weight of titania are added to a fluorine-containing silane compound (structural formula: CF ₃ CH ₂ CH ₂ Si).
50 parts by weight of (OCH ₃ ) ₃ ) was mixed, stirred, dried by heating, and pulverized with a jet mill to obtain an external additive H having a specific gravity of 3.9. (Adjustment of External Additive I) Fluorine-Containing Silane Compound (Structural Formula:
An average primary particle size of 25n was obtained in exactly the same manner as the external additive H except that 50 parts by weight of CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ) was replaced with 50 parts by weight of decyltrimethoxysilane.
External additive I having m and a specific gravity of 4.0 was obtained. (Preparation of External Additive J) In the external additive H, except that 50 parts by weight of the fluorine-containing silane compound was replaced by 20 parts by weight,
An external additive J having an average primary particle size of 25 nm and a specific gravity of 3.8 was obtained in the same manner as the external additive H. (Adjustment of external additive K) TiO (OH) produced by the above method
₂ 50 parts by weight of decyltrimethoxysilane are mixed with 100 parts and heated to react. After that, it was washed with water, filtered, dried at 120 ° C., and the soft agglomeration was released by a jet mill to obtain a titanium compound K having an average primary particle size of 25 nm and a specific gravity of 3.3.

[Production of Toner Particles] (Production of Toner Particles X) Binder Resin (Polyester Resin, Mw = 15000, Tg = 65 ° C.) 91 Parts Phthalocyanine Pigment (Blue 15: 3) 5 Parts Charge Control Agent (Bontron E88 4 parts, mixed with a Henschel mixer, melt-kneaded using a twin-screw continuous extruder (TEM48BS: Toshiba Machine Co., Ltd.), cooled, and then finely pulverized with a jet mill. Then, it was further classified by a classifier to obtain toner particles X having an average particle size of 7 μm.

(Production of Toner Particles Y) Binder Resin (Polyester Resin, Mw = 40000, Tg = 68 ° C.) 85 Parts Carbon Black (BP1300: Cabot Co.) 8 Parts Low Molecular Weight Polypropylene (Viscor 660P: Sanyo Kasei Co., Ltd.) ) 5 parts Low molecular weight polyethylene (molecular weight: 6000) 2 parts After mixing the above materials with a Henschel mixer, melt kneading with a continuous kneader (TEM35) manufactured by Toshiba Machine Co., cool and finely pulverize with a type I mill, and further inertia The toner particles Y having an average particle diameter of 9 μm were obtained by classification with a type classifier.

[Image Forming Apparatus] FIG. 1 is a schematic sectional view of an image forming apparatus used for image quality evaluation in the present invention. In FIG. 1, the photoconductor drum 1 and the developing roll 3 are arranged so as to have a constant gap, and the photoconductor drum 1 is charged by a roll charger 2 and then exposed to laser light to form an electrostatic latent image. The electrostatic latent image was formed by superposing an AC voltage and a DC voltage on the developing roll 3 and the developer supplying roll 4. The layer forming blade 5 made of silicone rubber was brought into contact with the developing roll 3 at a constant linear pressure to form a thin layer of toner. The peripheral speed of the photosensitive drum 1 is 60 mm / sec, and
The peripheral speed of the developing roll 3 was 90 mm / sec. A roll transfer device 6 was used for transferring the toner, and a blade type cleaner 7 was used for cleaning. Alumite was used as the material of the developing roll 3.

Example 1 100 parts by weight of the toner particles X obtained by the above method and 1.0 part by weight of the external additive A were mixed using a Henschel mixer, and then developed by sieving with a wind sieving machine at 106 μm. Agent 1 was obtained. Example 2 A developer 2 was obtained in the same manner as in Example 1 except that the external additive A was replaced with the external additive B. Example 3 A developer 3 was obtained in exactly the same manner as in Example 1 except that the external additive A was replaced with the external additive C. Example 4 A developer 4 was obtained in the same manner as in Example 1 except that the external additive A was replaced with the external additive D.

Example 5 A developer 5 was obtained in the same manner as in Example 2 except that the toner particles X were replaced by the toner particles Y. Example 6 A developer 6 was obtained in the same manner as in Example 5 except that the external additive B was replaced with the external additive E. Example 7 A developer 7 was obtained in the same manner as in Example 3 except that the toner particles X were replaced with the toner particles Y. The charge amount of the obtained developer 7 was -25 μc / g as measured by the above method. Example 8 A developer 8 was obtained in the same manner as in Example 6 except that the amount of the external additive added was changed to 0.5 part by weight.

Comparative Example 1 A developer 9 was obtained in the same manner as in Example 1 except that the external additive A was replaced with the external additive G. Comparative Example 2 A developer 10 was obtained in the same manner as in Example 1 except that the external additive A was replaced with the external additive H. Comparative Example 3 A developer 11 was obtained in the same manner as in Example 1 except that the external additive A was replaced with the external additive I.

Comparative Example 4 Developer 12 was prepared in the same manner as in Example 1 except that the external additive A used in Example 1 was replaced with the one obtained by dry-processing the surface of amorphous titanium having a particle size of 30 nm with silicone oil. Got Comparative Example 5 Except that the external additive A in Example 1 was replaced with silicone oil-treated silica fine particles having a particle size of 16 nm,
A developer 13 was obtained in exactly the same manner as in Example 1.

Comparative Example 6 A developer 14 was obtained in the same manner as in Example 5, except that the external additive B was replaced with the external additive I. Comparative Example 7 A developer 15 was obtained in the same manner as in Example 5 except that the external additive B was replaced with the external additive J. Comparative Example 8 A developer 16 was obtained in exactly the same manner as in Example 5, except that the external additive B in Example 5 was replaced with silica fine particles having a particle diameter of 12 nm that had been treated with hexamethyldisilazane. Comparative Example 9 Except that the external additive B in Example 5 was replaced with 0.5 parts by weight of silicone oil-treated silica fine particles having a particle size of 16 nm and 0.5 parts by weight of the external additive J, the same as Example 5. Developer 17 was obtained in the same manner. Comparative Example 10 A developer 18 was obtained in exactly the same manner as in Example 7 except that the external additive C was replaced with the external additive K.

The developers 1 to 18 obtained in the above respective examples are
In the image forming method using the image forming apparatus shown in FIG. 1, in an environment of high temperature and high humidity of 30 ° C. and 90% RH and 3 ° C. at 5 ° C.
A print test was performed on 20,000 sheets under a low temperature and low humidity environment of 0% RH. The results are shown in Table 1.

[0061]

[Table 1]

[Toner flow characteristics * 1] The fluidity of the toner was evaluated using an off-line auger dispenser (target dispense amount ≧ 700 mg / sec). As an evaluation standard, 700 or more was evaluated as ◯, and less than that was evaluated as x. [Initial charge amount * 2] Toner is conveyed onto the sleeve and measured by the suction tribo measurement method in each environment.
The amount of charge after copying 20,000 sheets was measured in the same manner. [Comprehensive charge evaluation * 3] Environmental difference = {initial charge amount (high temperature and high humidity ÷ low temperature and low humidity) + charge amount after running 20,000 sheets (high temperature and high humidity ÷ low temperature and low humidity)} x 1/2 and comprehensive evaluation is performed. Such a judgment was made. Environmental difference judgment criteria: ○ ≧ 0.7, Δ ≧ 0.5, × <0.5 Maintainability = {High temperature / high humidity charge amount (after 20,000 sheets ÷ initial stage) + Low temperature and low humidity charge amount (after 20,000 sheets ÷ Initial stage)} × 1/2 was used for the overall evaluation, and the following judgment was made. Criteria for maintainability: ○ ≧ 0.7, Δ ≧ 0.5, × <0.5 Charge distribution = The charge distribution of the toner on the sleeve after copying 20,000 sheets is measured by a charge distribution measuring device, and the distribution of It was calculated by dividing the center value by the width of the distribution. Judgment criteria: ○ ≧ 0.6, △ ≧ 0.4, × <0.4

[Comprehensive Image Quality Evaluation * 4] Fog: Sensitivity evaluation in which the background portion was observed with a magnifying glass of 50 times. ○: none, △: a little, ×: fairly, XX: very many. Density unevenness / conveyance failure: Solid density is 3 with Macbeth densitometer
Judgment is made by measuring points (A4 upper part to lower part). Density maintenance: Judgment was made by measuring the image densities at the initial stage and 10,000 sheets with a Macbeth densitometer. Image quality defect: Visually determine the image quality defect caused by the defect of the photosensitive material. Stains inside the machine: Visually judge the state of toner scattering and toner accumulation due to sleeve streaks. Line: Judged based on the image quality after copying 20,000 sheets and the deposits on the blade. Judgment criteria: ○: good image quality and blade △: good image quality, some adhesion to blade ×: problematic image quality (streaks occur) and blade XX: poor image quality and blade adhesion

[0064]

The one-component developer of the present invention is excellent in chargeability, charge rate, environmental dependence and charge distribution,
In addition, it is good in various characteristics as a one-component developer such as charge retention of the toner on the developer carrier, sleeve contamination, blade contamination, and photosensitive material scratch / contamination. The density is stable, and it is possible to obtain an excellent image quality without generation of lines due to background fog and contamination of the charging member.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an image forming apparatus used for image quality evaluation in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum, 2 ... Roll charger, 3 ... Development roll, 4 ... Developer supply roll, 5 ... Layer forming blade, 6 ...
Roll transfer device, 7 ... Blade type cleaner.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-6286 (JP, A) JP-A-9-316360 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9/08 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A one-component developer comprising toner particles containing a binder resin and a colorant and an additive, wherein the additive is a part or all of TiO (OH) ₂ and a fluorine-containing silane compound. A one-component developer comprising a titanium compound obtained by the above reaction. 2. The one-component developer according to claim 1, wherein the fluorine-containing silane compound is represented by the following formula (1) or formula (2). _{C n F 2n + 1 CH 2} CH 2 Si (CH 3) p X 3-p (1) ( wherein, X represents a hydrolyzable group, n represents 1, 4, 6, 8
Or 10 and p is 0 or 1. _{) C m F 2m + 1 -Ph} -CH 2 CH 2 Si (CH 3) q Y 3-q (2) ( wherein, Ph is a phenylene group, Y represents a hydrolyzable group, m is 1,4 , 6 or 8, and q is 0 or 1.) 3. An image forming method comprising a step of forming a latent image on a latent image holding member and a step of developing the obtained latent image with a developer on a developer carrying member, wherein the developer is An image forming method comprising using the one-component developer according to claim 1.